Pathogens

14 pages, 734 KiB

Open AccessReview

Insect Meals and Insect Antimicrobial Peptides as an Alternative for Antibiotics and Growth Promoters in Livestock Production

by Ewelina Patyra and Krzysztof Kwiatek

Pathogens 2023, 12(6), 854; https://doi.org/10.3390/pathogens12060854 - 20 Jun 2023

Cited by 16 | Viewed by 3584

Abstract

The extensive use of antibiotics in animal production has led to the development of antibiotic-resistant microorganisms and the search for alternative antimicrobial agents in animal production. One such compound may be antimicrobial peptides (AMPs), which are characterized by, among others, a wide range [...] Read more.

The extensive use of antibiotics in animal production has led to the development of antibiotic-resistant microorganisms and the search for alternative antimicrobial agents in animal production. One such compound may be antimicrobial peptides (AMPs), which are characterized by, among others, a wide range of biocidal activity. According to scientific data, insects produce the largest number of antimicrobial peptides, and the changing EU legislation has allowed processed animal protein derived from insects to be used in feed for farm animals, which, in addition to a protein supplement, may prove to be an alternative to antibiotics and antibiotic growth promoters due to their documented beneficial impact on livestock health. In animals that were fed feeds with the addition of insect meals, changes in their intestinal microbiota, strengthened immunity, and increased antibacterial activity were confirmed to be positive effects obtained thanks to the insect diet. This paper reviews the literature on sources of antibacterial peptides and the mechanism of action of these compounds, with particular emphasis on insect antibacterial peptides and their potential impact on animal health, and legal regulations related to the use of insect meals in animal nutrition. Full article

(This article belongs to the Special Issue Elimination of Pathogenic Microorganisms by Natural and Synthetic Compounds)

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17 pages, 2003 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of the Effect of Plectranthus amboinicus L. Leaf Extracts on the Bacterial Antioxidant System and Cell Membrane Integrity of Pseudomonas aeruginosa PA01 and Staphylococcus aureus NCTC8325

by Sheeba Sawant, Timothy C. Baldwin, Oliwia Metryka and Ayesha Rahman

Pathogens 2023, 12(6), 853; https://doi.org/10.3390/pathogens12060853 - 20 Jun 2023

Cited by 2 | Viewed by 3165

Abstract

Plectranthus amboinicus (Indian borage) has been extensively studied for its medicinal properties, which can be exploited to develop new antimicrobial therapeutics. The current study investigated the effect of Plectranthus amboinicus leaf extracts on the catalase activity, reactive oxygen species, lipid peroxidation, cytoplasmic membrane [...] Read more.

Plectranthus amboinicus (Indian borage) has been extensively studied for its medicinal properties, which can be exploited to develop new antimicrobial therapeutics. The current study investigated the effect of Plectranthus amboinicus leaf extracts on the catalase activity, reactive oxygen species, lipid peroxidation, cytoplasmic membrane permeability, and efflux pump activity in S. aureus NCTC8325 and P. aeruginosa PA01. As the enzyme catalase protects bacteria against oxidative stress, disruption of its activity creates an imbalance in reactive oxygen species (ROS) levels, which subsequently oxidizes lipid chains, leading to lipid peroxidation. In addition, bacterial cell membranes are a potential target for new antibacterial agents, as efflux pump systems play a crucial role in antimicrobial resistance. Upon exposure of the microorganisms to Indian borage leaf extracts, the observed catalase activity decreased by 60% and 20% in P. aeruginosa and S. aureus, respectively. The generation of ROS can cause oxidation reactions to occur within the polyunsaturated fatty acids of the lipid membranes and induce lipid peroxidation. To investigate these phenomena, the increase in ROS activity in P. aeruginosa and S. aureus was studied using H₂DCFDA, which is oxidized to 2′,7′-dichlorofluorescein (DCF) by ROS. Furthermore, the concentration of lipid peroxidation product (malondialdehyde) was assessed using the Thiobarbituric acid assay and was shown to increase by 42.4% and 42.5% in P. aeruginosa and S. aureus, respectively. The effect of the extracts on the cell membrane permeability was monitored using diSC3-5 dye and it was observed that the cell membrane permeability of P. aeruginosa increased by 58% and of S. aureus by 83%. The effect on efflux pump activity was investigated using Rhodamine-6-uptake assay, which displayed a decrease in efflux activity of 25.5% in P. aeruginosa and 24.2% in S. aureus after treatment with the extracts. This combination of different methods to study various bacterial virulence factors provides a more robust, mechanistic understanding of the effect of P. amboinicus extracts on P. aeruginosa and S. aureus. This study thus represents the first report of the assessment of the effect of Indian borage leaf extracts on bacterial antioxidant systems and bacterial cell membranes, and can facilitate the future development of bacterial resistance modifying agents derived from P. amboinicus. Full article

(This article belongs to the Special Issue Advances in Treatment of Biofilm Infections)

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(a) Effect of Indian leaf borage extracts on catalase activity in P. aeruginosa. (1) Untreated cells. (2) Ciprofloxacin-treated cells, drug control. (3) IB-extract-treated cells. (4) 1% DMSO-treated cells, solvent control. (b) Effect of Indian borage leaf extracts on catalase activity in S. aureus. (1) Untreated cells. (2) Ciprofloxacin-treated cells, drug control. (3) IB-extract-treated cells. (4) 1% DMSO-treated cells, solvent control. Full article ">Figure 2
Effect of IB leaf extracts on ROS concentration in P. aeruginosa and S. aureus. Untreated: untreated culture control; 1% DMSO: solvent control; Cipro: ciprofloxacin, drug control; IB: Indian borage leaf extract. The bar graph indicates the reactive oxygen species (ROS) intracellular concentrations in AU·CFU mL−1 in bacterial cells after exposure to different compounds. The vertical bars denote the mean values based on three replicates with error bars representing the standard deviation. The data labels above the bar graphs denote the ROS intracellular concentration in AU·CFU mL−1. The untreated P. aeruginosa samples displayed 28,975 AU·CFU mL−1 of ROS concentration, the concentration changed to 32,225 AU·CFU mL−1, 204,943.6 AU·CFU mL−1, and 45,060.6 AU·CFU mL−1 after exposure to 1% DMSO, cipro, and IB extracts, respectively. Similarly, the untreated S. aureus samples showed 27,375.33 AU·CFU mL−1. However, after 1% DMSO, Cipro and IB treatment, the ROS concentration changed to 34,006.3 AU·CFU mL−1, 186,044.3 AU·CFU mL−1, and 151,678.6 AU·CFU mL−1, respectively. The p value denoted by asterisks (***) reveals that ciprofloxacin and IB extracts had a significant (p < 0.001) effect on the ROS intracellular concentration levels in comparison with the untreated control. The non-significant effect of 1% DMSO on ROS activity is indicated by ns. Full article ">Figure 3
(a) Effect of IB extracts on cytoplasmic membrane integrity in P. aeruginosa. (b) Effect of IB leaf extract on cytoplasmic membrane integrity in S. aureus. Fluorescence: The fluorescence is observed at an excitation wavelength (622 nm) and an emission wavelength (670 nm). Untreated: untreated culture control; 1% DMSO: positive control; Cipro: ciprofloxacin, drug control; 20% acetone: solvent control; IB: Indian borage leaf extract. The graph indicates the fluorescence of diSC3-5 dye released at different time intervals after exposure to different treatments in P. aeruginosa (a) and S. aureus (b). In P. aeruginosa, the cipro and IB-treated samples show the highest dye release of 71% with 0.162 O. D and 58% with 0.15 O. D at 60 min, respectively, followed by 1% DMSO with 45% at 0.138 O. D and 20% acetone with 4.2% at 0.099 O.D. In S. aureus, the IB- and cipro-treated samples displayed the highest dye release of 83% with 0.181 O. D and 78% with 0.178 O. D at 60 mins, respectively, followed by dye release of 59% with 0.158 O. D of 1% DMSO-treated samples at 60 min. Full article ">Figure 4
Effect of IB leaf extracts on efflux pumps in P. aeruginosa and S. aureus evaluated using the R-6-G uptake assay. Untreated: untreated culture control; Reserpine: standard efflux pump inhibitor control; 1% DMSO: solvent control; Cipro: ciprofloxacin, drug control; IB: Indian borage leaf extract. The bar graph indicates the efflux pump inhibition (EPI) activity by comparing the absorbance of Rhodamine-6-G dye after exposure to different compounds. Data labels above the bar graphs denote % efflux pump inhibition. In P. aeruginosa, reserpine-treated samples showed a maximum efflux pump inhibition of 52.5% followed by ciprofloxacin at 35.5% and IB leaf extracts at 25.5%. In S. aureus, reserpine-treated samples showed 77% of EPI activity, followed by 48% and 24.2% of EPI activity by the ciprofloxacin and IB-treated samples. The p value is denoted by asterisks in the figure. The effect of IB leaf extracts on efflux pumps in P. aeruginosa showed a significant (p < 0.001) impact on the EPI activity. Similarly, in S. aureus, a significant (p < 0.05) effect, was recorded on the EPI activity after exposure to the IB leaf extracts. The p value denoted by asterisks (***) reveals that the ciprofloxacin and IB extracts had a significant (p < 0.001) effect on the EPI activity in comparison with untreated control. The non-significant effect of 1% DMSO on the EPI activity is indicated by ns. Full article ">Figure 5
Schematic presentation of the effect of P. ambioincus extracts on P. aeruginosa and S. aureus virulence factors. Oxidative stress occurs due to an imbalance in redox status. Reactive oxygen species are continuously generated in aerobic organisms. Catalases are involved in ROS elimination by catalyzing the conversion of hydrogen peroxide to water and oxygen. Improved enzymatic activity of catalases, decreases the accumulation of ROS, and helps in the survival and stability of the bacterial cells. However, a decline or disruption in the catalase activity increases ROS concentration, which attacks membrane lipids causing lipid peroxidation. The accumulation of lipid peroxidation by products such as malondialdehyde and HNE target lipids, DNA, and proteins such as bacterial transport protein, which causes a disruption or reduction in efflux pumps activity and helps in accumulating antibiotics within the cells. Ultimately, this leads to a disruption in cellular responses and causes cell death. Full article ">

19 pages, 3109 KiB

Open AccessArticle

TRIM16 Overexpression in HEK293T Cells Results in Cell Line-Specific Antiviral Activity

by Lance R. Nigos, Nichollas E. Scott, Andrew G. Brooks, Malika Ait-Goughoulte, Sarah L. Londrigan, Patrick. C. Reading and Rubaiyea Farrukee

Pathogens 2023, 12(6), 852; https://doi.org/10.3390/pathogens12060852 - 20 Jun 2023

Cited by 2 | Viewed by 3117

Abstract

Host cell restriction factors are intracellular proteins that can inhibit virus replication. Characterisation of novel host cell restriction factors can provide potential targets for host-directed therapies. In this study, we aimed to assess a member of the Tripartite-motif family protein (TRIM) family, TRIM16, [...] Read more.

Host cell restriction factors are intracellular proteins that can inhibit virus replication. Characterisation of novel host cell restriction factors can provide potential targets for host-directed therapies. In this study, we aimed to assess a member of the Tripartite-motif family protein (TRIM) family, TRIM16, as a putative host cell restriction factor. To this end, we utilized constitutive or doxycycline-inducible systems to overexpress TRIM16 in HEK293T epithelial cells and then tested for its ability to inhibit growth by a range of RNA and DNA viruses. In HEK293T cells, overexpression of TRIM16 resulted in potent inhibition of multiple viruses, however, when TRIM16 was overexpressed in other epithelial cell lines (A549, Hela, or Hep2), virus inhibition was not observed. When investigating the antiviral activity of endogenous TRIM16, we report that siRNA-mediated knockdown of TRIM16 in A549 cells also modulated the mRNA expression of other TRIM proteins, complicating the interpretation of results using this method. Therefore, we used CRISPR/Cas9 editing to knockout TRIM16 in A549 cells and demonstrate that endogenous TRIM16 did not mediate antiviral activity against the viruses tested. Thus, while initial overexpression in HEK293T cells suggested that TRIM16 was a host cell restriction factor, alternative approaches did not validate these findings. These studies highlight the importance of multiple complementary experimental approaches, including overexpression analysis in multiple cell lines and investigation of the endogenous protein, when defining host cell restriction factors with novel antiviral activity. Full article

(This article belongs to the Special Issue Cell Intrinsic Innate Responses to Viral Infections)

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Overexpression of TRIM16 in HEK293T cells results in antiviral activity against a broad range of viruses. (A) TRIM16 with an N-terminal Flag tag was constitutively overexpressed in HEK293T cells under hygromycin selection. Intracellular FLAG expression was measured by flow cytometric analysis. CTRL cells (overexpressing an irrelevant intracellular protein, cytoplasmic chicken ovalbumin) were included as a control. (B) HEK293T cells were transduced with lentivirus to express FLAG-tagged TRIM16 and expression was induced in the presence of the antibiotic doxycycline (DOX). Cells were cultured overnight with (DOX) or without (No DOX) 1 μg/mL of DOX and then intracellular FLAG expression was measured by flow cytometric analysis. (C) Dox-inducible HEK293T CTRL or TRIM16 cells were cultured overnight in the presence (+DOX) or absence (-DOX) of 1 μg/mL of DOX, before lysates were analysed by SDS-PAGE and Western blot using an anti-FLAG mAb. Lysates from cells constitutively overexpressing TRIM16 were also analysed. Calnexin was included as a loading control. (D) HEK293T cells constitutively overexpressing CTRL or TRIM16 proteins were infected with different viruses (RSV MOI 1, HMPV MOI 2, PIV MOI 1, IAV MOI 5, HSV MOI 1) and virus titres were determined 2 h and either 24 h (IAV) or 48 h post-infection (hpi). Combined titres from two independent experiments are shown. (E) DOX-inducible HEK293T cells were cultured overnight in the presence (DOX) or absence (No DOX) of 1 μg/mL DOX and then infected with different viruses (RSV MOI 0.1, HMPV MOI 1, PIV MOI 1, IAV MOI 0.1, HSV MOI 1). Virus titres at 24 (IAV) or 48 hpi were determined for each condition. Representative data from two independent experiments are shown. Black dots represent individual data points. Statistical analysis of viral titres was performed using an unpaired Student’s two-sample t-test with p-values reported as follows: * <0.5, ** <0.1, *** <0.01, **** <0.001. (F) HEK293T cells (CTRL and constitutively overexpressing TRIM16) were infected with RSV A2 (MOI 2) and then prepared for proteomic analysis at 48 hpi. Mass spectrometry analysis shows downregulation of all RSV proteins (pink) in TRIM16 overexpressing cells compared to CTRL cells. Host proteins upregulated in infected TRIM16 overexpressing cells compared to CTRL cells are coloured green, and downregulated host proteins are coloured brown. LOD—limit of detection. Full article ">Figure 2
Inducible TRIM16 expression does not mediate antiviral activity in other cell lines. (A) Different cell lines (A549, Hela, Hep2, and Vero) expressing DOX-inducible FLAG-tagged TRIM16 were generated. Cells were cultured overnight in the presence (DOX) or absence (No Dox) of 1 μg/mL DOX and then intracellular FLAG expression was measured by flow cytometry. (B–D) Different cell lines with DOX-inducible CTRL or FLAG-tagged TRIM16 were cultured overnight in the presence (DOX) or absence (No DOX) of 1 μg/mL DOX and then infected with either B) RSV (A549 MOI 0.1, Hela MOI 0.01, Hep2 MOI 0.01, Vero MOI 0.1), (C) IAV (MOI 5 for all cell lines) or (D) HSV-1 (MOI 1 for all cell lines). Virus titres were determined either 24 (IAV) or 48 hpi. B/C/D show data from triplicate samples that are representative of at least two independent experiments. Black dots represent individual data points. All comparisons between groups were performed using an unpaired Student’s two-sample t-test with p-values reported as follows: * <0.5, ** <0.1, *** <0.01, **** <0.001. LOD—limit of detection. Full article ">Figure 3
Investigating the antiviral activity of endogenous TRIM16 using siRNA-based knockdown (KD). (A) Expression of endogenous TRIM16 mRNA in different cell lines was determined by qPCR using primers specific to TRIM16 and results are expressed relative to two housekeeping genes (HKG): GAPDH and TBP. (B) A549 cells were cultured in media alone (No IFN) or media supplemented with IFN-α (1000 U/mL) or IFN-γ (50 ng/mL) for 24 h and then subjected to qPCR for TRIM16 expression. Expression levels of IFITM3, a well-characterised IFN-inducible gene, were also determined. (C) A549 cells were treated with 10 μM TRIM16 siRNA (TRIM16 KD) or with non-targeted control siRNA (NTC) for 72 h before knockdown efficiency was assessed by qPCR for TRIM16 mRNA expression. (D) A549 cells treated for 72 h with TRIM16 or NTC siRNA were then infected with RSV (MOI 0.01 or MOI 0.1), IAV (MOI 0.1), or HSV-1 (MOI 0.01). Virus titres were determined at 24 and 48 hpi. Representative data from two independent experiments are shown. (E) A549 cells were treated with TRIM16 or NTC siRNA for 72 h before the mRNA expression of different TRIM proteins was determined using qPCR. Black dots represent individual data points. Statistical analysis of ordinal scale data (e.g., relative expression data in A/B/C/E) were performed using a Mann–Whitney U test/Wilcoxon Rank-Sum test. Virus titre data was analysed using an unpaired two-sample Student’s t-test. The p-values are indicated as follows: * <0.5, ** <0.1, *** <0.01, **** <0.001. LOD—limit of detection. Full article ">Figure 4
Investigating the antiviral activity of endogenous TRIM16 in A549 cells using CRISPR/Cas9 editing. (A) A549 TRIM16 knockout (TRIM16 KO) and control cell lines (Scrambled) were generated using CRISPR/Cas9 editing. TRIM16 protein expression in bulk A549 cell populations was assessed by Western blot analysis using a TRIM16-specific mAb. Actin is included as a loading control. (B) mRNA expression of different TRIM proteins in TRIM16 KO or Scrambled control cell lines was determined using qPCR and data were normalized to expression levels of two HKG (GAPDH and TBP). (C) Bulk TRIM16 KO or Scrambled A549 cell populations were infected with RSV (MOI 0.01 or 0.1), IAV (MOI 0.1), and HSV-1 (MOI 0.01), and titres of infectious virus were determined at 24 and 48 hpi. Representative data from two independent experiments are shown. (D) Clonal lines of TRIM16 KO or Scrambled A549 cells were generated by limiting dilution and analysed by Western blot using a TRIM16-specific mAb with actin included as a loading control. (E) Clonal TRIM16 KO or Scrambled cells were infected with RSV (MOI 0.01 or 0.1) and virus titres were determined at 24 and 48 hpi. Data from each clone are shown in different colours (clone 1—red, clone 2—green, clone 3—blue). Representative data from two independent experiments are shown. Black dots represent individual data points. Statistical analysis of ordinal scale data (e.g., relative expression of different TRIMS) was performed using a Mann–Whitney U test/Wilcoxon Rank-Sum test. Virus titre data were analysed using an unpaired two-sample Student’s t-test. The p-values are indicated as follows: * <0.5, ** <0.1, *** <0.01, **** <0.001. LOD—limit of detection. Full article ">

21 pages, 1445 KiB

Open AccessEditor’s ChoiceReview

An Overview of Angiostrongylus cantonensis (Nematoda: Angiostrongylidae), an Emerging Cause of Human Angiostrongylosis on the Indian Subcontinent

by Divakaran Pandian, Tomáš Najer and David Modrý

Pathogens 2023, 12(6), 851; https://doi.org/10.3390/pathogens12060851 - 20 Jun 2023

Cited by 9 | Viewed by 6706

Abstract

Human angiostrongylosis is an emerging zoonosis caused by the larvae of three species of metastrongyloid nematodes of the genus Angiostrongylus, with Angiostrongylus cantonensis (Chen, 1935) being dominant across the world. Its obligatory heteroxenous life cycle includes rats as definitive hosts, mollusks as intermediate [...] Read more.

Human angiostrongylosis is an emerging zoonosis caused by the larvae of three species of metastrongyloid nematodes of the genus Angiostrongylus, with Angiostrongylus cantonensis (Chen, 1935) being dominant across the world. Its obligatory heteroxenous life cycle includes rats as definitive hosts, mollusks as intermediate hosts, and amphibians and reptiles as paratenic hosts. In humans, the infection manifests as Angiostrongylus eosinophilic meningitis (AEM) or ocular form. Since there is no comprehensive study on the disease in the Indian subcontinent, our study aims at the growing incidence of angiostrongylosis in humans, alongside its clinical course and possible causes. A systematic literature search revealed 28 reports of 45 human cases from 1966 to 2022; eosinophilic meningitis accounted for 33 cases (75.5%), 12 cases were reported as ocular, 1 case was combined, and 1 case was unspecified. The presumed source of infection was reported in 5 cases only. Importantly, 22 AEM patients reported a history of eating raw monitor lizard (Varanus spp.) tissues in the past. As apex predators, monitor lizards accumulate high numbers of L3 responsible for acute illness in humans. For ocular cases, the source was not identified. Most cases were diagnosed based on nematode findings and clinical pathology (primarily eosinophilia in the cerebrospinal fluid). Only two cases were confirmed to be A. cantonensis, one by immunoblot and the other by q-PCR. Cases of angiostrongylosis have been reported in Delhi, Karnataka, Kerala, Maharashtra, Madhya Pradesh, Puducherry, Telangana, and West Bengal. With a population of more than 1.4 billion, India is one of the least studied areas for A. cantonensis. It is likely that many cases remain undetected/unreported. Since most cases have been reported from the state of Kerala, further research may focus on this region. Gastropods, amphibians, and reptiles are commonly consumed in India; however, typical preparation methods involve cooking, which kills the nematode larvae. In addition to studying rodent and mollusk hosts, monitor lizards can be used as effective sentinels. Sequence data are urgently needed to answer the question of the identity of Angiostrongylus-like metastrongylid nematodes isolated from all types of hosts. DNA-based diagnostic methods such as q-PCR and LAMP should be included in clinical diagnosis of suspected cases and in studies of genetic diversity and species identity of nematodes tentatively identified as A. cantonensis. Full article

(This article belongs to the Special Issue Rat Lungworm Disease)

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Developmental stages of Angiostrongylus cantonensis in intermediate and definitive hosts; Illustrative pictures depict the laboratory strain of Angiostrongylus cantonensis from Fatu Hiva, derived from snails from the Marquesas Islands, French Polynesia [<a href="#B14-pathogens-12-00851" class="html-bibr">14</a>]. (A) Mixture of male and female adults removed from pulmonary arteries of a laboratory rat; females are larger (up to 30–35 mm), with typical barber-pole appearance, caused by the interweaving of the intestine and uterus; males (arrowheads) are smaller (max 15–25 mm), whitish, with well-developed bursa copulatrix; scale bar = 5 mm. (B) First-stage larva as shed in rat feces, scale bar = 50 µm. (C) Third-stage larva from a gastropod intermediate host, scale bar = 50 µm. Full article ">Figure 2
Schematic distribution of Angiostrongylus cantonensis reports on the Indian subcontinent. The red areas indicate countries or states with published records of angiostrongylosis, the black dots show cases—large dots multiple cases, and small dots single cases. Exact location of one Nepalese case is unknown, therefore, it is not indicated. The borders between Indian states are not shown, the map background was downloaded from <a href="https://d-maps.com" target="_blank">https://d-maps.com</a>, accessed on 8 November 2022. Full article ">Figure 3
Diversity of rat species (Rattini) on the Indian subcontinent. The grayscale corresponds to the number of rat species described from each country or state, as indicated in the figure. Borders between countries white; coast, borders between Indian states, and outline of the subcontinent black. The map background was downloaded from <a href="https://d-maps.com" target="_blank">https://d-maps.com</a>, accessed on 8 November 2022. Full article ">

21 pages, 737 KiB

Open AccessEditor’s ChoiceArticle

Risk Factors for Hepatitis E Virus Infection and Eating Habits in Kidney Transplant Recipients

by Eva Wu, Nadine Koch, Friederike Bachmann, Marten Schulz, Evelyn Seelow, Ulrike Weber, Johannes Waiser, Fabian Halleck, Mirko Faber, Claus-Thomas Bock, Kai-Uwe Eckardt, Klemens Budde, Jörg Hofmann, Peter Nickel and Mira Choi

Pathogens 2023, 12(6), 850; https://doi.org/10.3390/pathogens12060850 - 20 Jun 2023

Cited by 2 | Viewed by 2192

Abstract

There is a significant risk for ongoing and treatment-resistant courses of hepatitis E virus (HEV) infection in patients after solid organ transplantation. The aim of this study was to identify risk factors for the development of hepatitis E, including the dietary habits of [...] Read more.

There is a significant risk for ongoing and treatment-resistant courses of hepatitis E virus (HEV) infection in patients after solid organ transplantation. The aim of this study was to identify risk factors for the development of hepatitis E, including the dietary habits of patients. We conducted a retrospective single-center study with 59 adult kidney and combined kidney transplant recipients who were diagnosed with HEV infection between 2013 and 2020. The outcomes of HEV infections were analyzed during a median follow-up of 4.3 years. Patients were compared with a control cohort of 251 transplant patients with elevated liver enzymes but without evidence of an HEV infection. Patients’ alimentary exposures during the time before disease onset or diagnosis were assessed. Previous intense immunosuppression, especially treatment with high-dose steroids and rituximab, was a significant risk factor to acquire hepatitis E after solid organ transplantation. Only 11 out of 59 (18.6%) patients reached remission without further ribavirin (RBV) treatment. A total of 48 patients were treated with RBV, of which 19 patients (39.6%) had either viral rebounds after the end of treatment or did not reach viral clearance at all. Higher age (>60 years) and a BMI ≤ 20 kg/m² were risk factors for RBV treatment failure. Deterioration in kidney function with a drop in eGFR (p = 0.046) and a rise in proteinuria was more common in patients with persistent hepatitis E viremia. HEV infection was associated with the consumption of undercooked pork or pork products prior to infection. Patients also reported processing raw meat with bare hands at home more frequently than the controls. Overall, we showed that the intensity of immunosuppression, higher age, a low BMI and the consumption of undercooked pork meat correlated with the development of hepatitis E. Full article

(This article belongs to the Special Issue Hepatitis E Virus (HEV) Infection among Humans and Animals: Epidemiology, Clinical Characteristics, Treatment and Prevention)

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13 pages, 1600 KiB

Open AccessArticle

Estimating the Impact of Consecutive Blood Meals on Vector Competence of Aedes albopictus for Chikungunya Virus

by Eva Veronesi, Anca Paslaru, Julia Ettlin, Damiana Ravasi, Eleonora Flacio, Matteo Tanadini and Valeria Guidi

Pathogens 2023, 12(6), 849; https://doi.org/10.3390/pathogens12060849 - 20 Jun 2023

Cited by 2 | Viewed by 1559

Abstract

The continuous expansion of Aedes albopictus in Europe and the increases in autochthonous arboviruses transmissions in the region urge a better understanding of the virus transmission dynamic. Recent work described enhanced chikungunya virus (CHIKV) dissemination in Aedes aegypti mosquitoes exposed to a virus-free [...] Read more.

The continuous expansion of Aedes albopictus in Europe and the increases in autochthonous arboviruses transmissions in the region urge a better understanding of the virus transmission dynamic. Recent work described enhanced chikungunya virus (CHIKV) dissemination in Aedes aegypti mosquitoes exposed to a virus-free blood meal three days after their infection with CHIKV. Our study investigated the impact of a second blood meal on the vector competence of Ae. albopictus from southern Switzerland infected with CHIKV. Seven-day-old Ae. albopictus females were exposed to CHIKV-spiked blood and incubated at constant (27 °C) and fluctuating (14–28 °C) temperatures. Four days post-infection (dpi), some of these females were re-fed with a non-infectious blood meal. Virus infectivity, dissemination, transmission rate, and efficiency were investigated at seven and ten dpi. No enhanced dissemination rate was observed among females fed a second time; however, re-fed females have shown higher transmission efficiency than those fed only once after seven days post-infection and incubated under a fluctuating temperature regime. Vector competence for CHIKV was confirmed in Ae. albopictus from southern Switzerland. We did not observe an increase in dissemination rates among mosquitoes fed a second time (second blood meal), regardless of the temperature regime. Full article

(This article belongs to the Special Issue Mosquito-Borne Viruses)

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12 pages, 4173 KiB

Open AccessArticle

Dose-Dependent Inhibitory Effect of Probiotic Lactobacillus plantarum on Streptococcus mutans-Candida albicans Cross-Kingdom Microorganisms

by Jianhang Bao, Xinyan Huang, Yan Zeng, Tong Tong Wu, Xingyi Lu, Gina Meng, Yanfang Ren and Jin Xiao

Pathogens 2023, 12(6), 848; https://doi.org/10.3390/pathogens12060848 - 20 Jun 2023

Cited by 6 | Viewed by 2289

Abstract

Dental caries is one of the most common chronic diseases worldwide. Streptococcus mutans and Candida albicans are two major pathogens associated with dental caries. Several recent studies revealed that Lactobacillus plantarum inhibits S. mutans and C. albicans in biofilms and in a rodent [...] Read more.

Dental caries is one of the most common chronic diseases worldwide. Streptococcus mutans and Candida albicans are two major pathogens associated with dental caries. Several recent studies revealed that Lactobacillus plantarum inhibits S. mutans and C. albicans in biofilms and in a rodent model of dental caries. The aim of this study was to investigate the dose-dependent effect of L. plantarum against S. mutans and C. albicans in a planktonic model that simulated a high-caries-risk clinical condition. Mono-, dual-, and multi-species models were utilized, with five doses of L. plantarum (ranging from 1.0 × 10⁴ to 1.0 × 10⁸ CFU/mL). Real-time PCR was used to assess the expression of the virulence genes of C. albicans and S. mutans and the genes of L. plantarum. Student’s t-tests and one-way ANOVA, followed by post hoc tests, were employed to compare the cell viability and gene expression among groups. A dose-dependent inhibition on C. albicans and S. mutans was observed with increased dosages of L. plantarum. L. plantarum at 10⁸ CFU/mL demonstrated the highest antibacterial and antifungal inhibitory effect in the dual- and multi-species models. Specifically, at 20 h, the growth of C. albicans and S. mutans was suppressed by 1.5 and 5 logs, respectively (p < 0.05). The antifungal and antibacterial effects were attenuated in lower doses of L. plantarum (10⁴–10⁷ CFU/mL). The expression of C. albicans HWP1 and ECE 1 genes and S. mutans lacC and lacG genes were significantly downregulated with an added 10⁸ CFU/mL of L. plantarum (p < 0.05). The addition of 10⁸ CFU/mL L. plantarum further inhibited the hyphae or pseudohyphae formation of C. albicans. In summary, L. plantarum demonstrated dose-dependent antifungal and antibacterial effects against C. albicans and S. mutans. L. plantarum emerged as a promising candidate for the creation of novel antimicrobial probiotic products targeting dental caries prevention. Further research is warranted to identify the functional metabolites produced by L. plantarum at different dosages when interacting with C. albicans and S. mutans. Full article

(This article belongs to the Special Issue Advanced Research on the Streptococcus mutans)

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Figure 1
Dynamic changes in the viable cells of C. albicans, S. mutans, and L. plantarum in mono-, dual-, and multi-species models. (A,B) C. albicans viable cells in dual- and multi-species conditions. (C,D) S. mutans viable cells in dual- and multi-species conditions. (E) L. plantarum viable cells in mono-species condition. (F) L. plantarum viable cells in C. albicans presence dual-species condition. (G) L. plantarum viable cells in S. mutans presence dual-species condition. (H) L. plantarum viable cells in multi-species condition. Overall, dose-dependent antimicrobial and antifungal effects were seen for L. plantarum; 108 CFU/mL of L. plantarum showed inhibition on the growth of C. albicans and S. mutans. The dotted line represents the control groups in each model. Full article ">Figure 2
Changes in species composition in multi-species. The composition of each microorganism in multi-species condition is shown. (A–E) The composition of C. albicans, S. mutans, and L. plantarum in multi-species condition. Full article ">Figure 3
Effect of L. plantarum on the expression of C. albicans and S. mutans genes in multi-species model at 20 h. qRT-PCR was performed for S. mutans and C. albicans genes of interest for mixed-species culture at 20 h. S. mutans (A) and C. albicans (B) gene expression ratios are shown, and the comparison is relative to S. mutans and C. albicans dual-species. p values were determined by one-way ANOVA with post hoc test. * p < 0.05, ** p < 0.01, **** p < 0.0001. Full article ">Figure 4
Dose-related expression of L. plantarum gene in mono-species model. qRT-PCR was performed for L. plantarum genes of interest for mono-species culture at 20 h. L. plantarum gene expression ratio is shown, and the comparison is relative to 104 CFU/mL L. plantarum mono-species group. p values were determined by one-way ANOVA with post hoc test. * p < 0.05, *** p < 0.001, **** p < 0.0001. Full article ">Figure 5
Expression of L. plantarum genes when interacting with S. mutans and C. albicans in multi-species model at 20 h. qRT-PCR was performed for L. plantarum genes of interest for mixed-species culture at 20 h. L. plantarum gene expression ratio is shown (A–O), and the comparison is relative to L. plantarum mono-species group. p values were determined by t-test. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001. Full article ">Figure 6
Dose-dependent inhibition of C. albicans hyphae formation by L. plantarum gene in multi-species model at × 100 magnification. (A) S. mutans and C. albicans grown in dual-species model at 20 h. (B–F) S. mutans and C. albicans grown with addition of various doses of L. plantarum at 20 h. The addition of 108 CFU/mL L. plantarum inhibited the growth of C. albicans and the transition from yeast to hyphae or pseudohyphae form. These are representative images of multiple fields of view. Full article ">

16 pages, 1282 KiB

Open AccessArticle

Barriers with Valve Mechanisms Are Predicted to Protect Crops from Slug Carriers of Rat Lungworm Disease

by Genevieve C. Pang, Amy T. Hou, Ryan Tamashiro, Kristin M. Mills and Lorrin W. Pang

Pathogens 2023, 12(6), 847; https://doi.org/10.3390/pathogens12060847 - 19 Jun 2023

Viewed by 1303

Abstract

Angiostrongyliasis (Rat Lungworm disease) is an emerging parasitic disease caused by the ingestion of gastropods infected with the neurotropic nematode Angiostrongylus cantonensis. The reduction of crop infestation with infected slug carriers may vary widely by protection method. We explored the application of [...] Read more.

Angiostrongyliasis (Rat Lungworm disease) is an emerging parasitic disease caused by the ingestion of gastropods infected with the neurotropic nematode Angiostrongylus cantonensis. The reduction of crop infestation with infected slug carriers may vary widely by protection method. We explored the application of barriers with valve mechanisms, whereby selective directional forces caused a greater number of slugs to exit than enter the protected plot, leading to decreased slug population densities at a steady state. Using field data, we constructed predictive models to estimate slug population densities at a steady state in protected plots with (1) no valve effect, (2) a valve effect, (3) no valve effect with a single breach of the barrier, (4) a valve effect with a single breach of the barrier, (5) a valve effect with a constant breach of the barrier, and (6) a repelling effect. For all scenarios, plots protected using a barrier with a valve effect had consistently lower slug densities at a steady state. Our findings support the use of barriers with valve mechanisms under different conditions, and potentially in combination with other interventions to reduce the contamination of crops by slug carriers of A. cantonensis. Improving barriers extends beyond disease mitigation to economic and cultural impacts on the local farmer and consumer communities. Full article

(This article belongs to the Special Issue Rat Lungworm Disease)

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25 pages, 3789 KiB

Open AccessArticle

The Immune Response in the Uteri and Placentae of Chlamydia abortus-Infected Ewes and Its Association with Pregnancy Outcomes

by Sergio Gaston Caspe, David Andrew Ewing, Morag Livingstone, Clare Underwood, Elspeth Milne, Neil Donald Sargison, Sean Ranjan Wattegedera and David Longbottom

Pathogens 2023, 12(6), 846; https://doi.org/10.3390/pathogens12060846 - 19 Jun 2023

Cited by 3 | Viewed by 2058

Abstract

The enzootic abortion of ewes, caused by the bacterium Chlamydia abortus (C. abortus), is one of the main causes of abortion in sheep. There are multiple contributory factors, including chlamydial growth, host immune response, and hormonal balance, that result in different [...] Read more.

The enzootic abortion of ewes, caused by the bacterium Chlamydia abortus (C. abortus), is one of the main causes of abortion in sheep. There are multiple contributory factors, including chlamydial growth, host immune response, and hormonal balance, that result in different pregnancy outcomes, such as abortion, the birth of weak lambs that may die, or healthy lambs. This study aimed to determine the relationship between phenotypical patterns of immune cell infiltration and different pregnancy outcomes in twin-bearing sheep (both lambs born dead; one alive and one dead; both alive) when experimentally infected with C. abortus. Both the sheep uteri and placentae were collected after parturition. All samples were analysed for specific immune cell features, including cell surface antigens and the T-regulatory (Treg) cell-associated transcription factor and cytokines, by immunohistochemistry and in situ hybridisation. Some of these immunological antigens were evaluated in ovine reproductive tissues for the first time. Differential patterns of T helper/Treg cells revealed significant group effects in the placentae. It suggests the potential role that the balance of lymphocyte subsets may play in affecting different pregnancy outcomes in C. abortus-infected sheep. The present study provides novel detailed information about the immune responses observed at the maternofoetal interface in sheep at the time of pre-term abortion or lambing. Full article

(This article belongs to the Special Issue New Insights into Brucellosis and Other Abortive Diseases in Ruminants)

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Placentae from the different clinical outcome groups. Placentae were identified by the number of the sheep, group (DD: dead/dead; DL: dead/live; LL: live/live; NC: negative control), and the number of placentae collected from each sheep (P1 and P2). Placentae showed different degrees of gross lesions (extent of lesions expressed as a percentage of placental surface area, shown in brackets): (A) Ewe 1 P1 DD (60%); (B) Ewe 2 P1 DD (100%); (C) Ewe 2 P2 DD (100%); (D) Ewe 3 P1 DD (50%); (E) Ewe 4 P1 DL (90%); (F) Ewe 4 P2 DL (0%); (G) Ewe 5 DL (fused placentae) P1 (90%) and P2 (25%); (H) Ewe 6 P1 DL (100%); (I) Ewe 7 P1 LL (80%); (J) Ewe 7 P2 LL (40%); (K) Ewe 8 P1 LL (10%); (L) Ewe 8 P2 LL (40%); (M) Ewe 9 P1 NC (0%); (N) Ewe 9 P2 NC (0%); (O) Ewe 10 P1 NC (0%); (P) Ewe 10 P2 NC (0%). Full article ">Figure 2
IHC labelling for C. abortus in the placenta. The figure depicts immunolabelling for C. abortus in the placenta using mAb 4/11 targeting C. abortus-MOMP in the experimental groups: Dead/Dead (DD), Dead/Live (DL), Live/Live (LL), and Negative Control (NC). C. abortus-MOMP is labelled in dark red over a blue counterstain. IHC used the AEC red substrate and was counterstained with haematoxylin. Full article ">Figure 3
IHC labelling for C. abortus in the uteri. The figure shows immunolabelling for C. abortus in the placenta using mAb 4/11 targeting C. abortus-MOMP in the experimental groups: Dead/Dead (DD), Dead/Live (DL), Live/Live (LL), and Negative Control (NC). C. abortus-MOMP is labelled in dark red over a blue counterstain. IHC used the AEC red substrate and counterstained it with haematoxylin. Full article ">Figure 4
Labelling of ovine uteri using IHC for CD Markers. IHC using mAb targeted CD4 T cells, FoxP3 cells, CD8 T cells, and IL-10 cells were labelled with AEC red (Vector Laboratories, Peterborough, UK) over a blue counterstain with haematoxylin. Full article ">Figure 5
IHC labelling for lymphoid cells in the placenta. IHC using mAb-targeting NK cells, the γδ- T cell (TCR and WC1 antigen), and TNF-α; these are labelled with AEC red (Vector Laboratories, Peterborough, UK) over a blue counterstain with haematoxylin. Full article ">Figure 6
mRNA detection of IFN-γ by ISH in the placenta. Dead/Dead (DD), Dead/Live (DL), Live/Live (LL), and Negative Control (NC). ACD RNAscopeTM RED kit (Biotechne, Minneapolis, MI, USA). Full article ">Figure 7
Box and whisker plots showing the multiple comparisons of immune markers and the C. abortus marker in the uteri and placentae. Different markers for IHC (C. abortus MOMP, CD4 T cells, CD8 T cells, γδ-T cells (γδ-TCR and γδ-WC1), NKp46, TNF-α, IL-10, FoxP3) and ISH (IFN-γ and IL-17A) in different ewe outcome groups (DD, DL, LL, and NC). Every boxplot identifies the uteri in orange and the corresponding placentae in light blue for each group of animals. Boxes in the plots are shown using the first quartile (bottom line of the box), median (central line in the box), and third quartile (upper line of the box). The whiskers (vertical lines) show a measure in the range, which could be extended to the most extreme data point no more than 1.5 times the interquartile range from the box. Outlier data are shown as solid points. Full article ">

15 pages, 4753 KiB

Open AccessArticle

Bis-Benzylisoquinoline Alkaloids Inhibit Porcine Epidemic Diarrhea Virus by Disrupting Virus Entry

by Caisheng Zhang, Huan Chen, Liumei Sun, Pu Zhao, Chuanxiang Qi, Ying Yang, Anqi Si, Yingjuan Qian and Yong-Sam Jung

Pathogens 2023, 12(6), 845; https://doi.org/10.3390/pathogens12060845 - 19 Jun 2023

Cited by 4 | Viewed by 2063

Abstract

The porcine epidemic diarrhea virus (PEDV), belonging to the α-coronavirus, is the causative agent of porcine epidemic diarrhea (PED). Presently, protection from the existing PEDV vaccine is not effective. Therefore, anti-PEDV compounds should be studied. Berbamine (BBM), Fangchinoline (FAN), and (+)-Fangchinoline (+FAN), are [...] Read more.

The porcine epidemic diarrhea virus (PEDV), belonging to the α-coronavirus, is the causative agent of porcine epidemic diarrhea (PED). Presently, protection from the existing PEDV vaccine is not effective. Therefore, anti-PEDV compounds should be studied. Berbamine (BBM), Fangchinoline (FAN), and (+)-Fangchinoline (+FAN), are types of bis-benzylisoquinoline alkaloids that are extracted from natural medicinal plants. These bis-benzylisoquinoline alkaloids have various biological activities, including antiviral, anticancer, and anti-inflammatory properties. In this study, we found that BBM, FAN, and +FAN suppressed PEDV activity with a 50% inhibitory concentration of 9.00 µM, 3.54 µM, and 4.68 µM, respectively. Furthermore, these alkaloids can decrease the PEDV-N protein levels and virus titers in vitro. The time-of-addition assay results showed that these alkaloids mainly inhibit PEDV entry. We also found that the inhibitory effects of BBM, FAN, and +FAN on PEDV rely on decreasing the activity of Cathepsin L (CTSL) and Cathepsin B (CTSB) by suppressing lysosome acidification. Taken together, these results indicated that BBM, FAN, and +FAN were effective anti-PEDV natural products that prevented PEDV entry and may be considered novel antiviral drugs. Full article

(This article belongs to the Special Issue Swine Viral Diseases)

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CC50 and IC50 of Berbamine (BBM), Fangchinoline (FAN), and (+)-Fangchinoline (+FAN). (A–C) The chemical structures of BBM, FAN, and +FAN. (D) Vero-E6 cells were treated with 0, 5, 10, and 20 μM of BBM, FAN, and +FAN for 14 h, and then treated with CCK-8 for 2 h. The OD450 value was measured. (E) The Half Maximal Inhibitory Concentration (IC50) was determined by cell-based ELISA assay and calculated by nonlinear regression analysis. The horizontal dotted lines show 50% cell viability or 50% inhibition rate. Full article ">Figure 2
BBM, FAN, and +FAN inhibit PEDV infection in vitro. (A) Overall scheme for Vero-E6 cells infection and treatment with BBM (10 μM), FAN (5 μM), and +FAN (5 μM); the solid gray line refers to the PEDV infection period and the dotted gray line refers to the compound treatment. (B) The protein sample was harvested at 12 h post-infection (h.p.i.) and PEDV-N and actin protein levels were determined by Western blotting. (C) The cells were harvested at 12 h.p.i., and the PEDV, HLJBY strain titer was determined by the PFU assay. (D) The cells were fixed and permeabilized at 12 h.p.i. and PEDV-N fluorescence intensity was determined by an IFA assay. The results were analyzed using the Student t-test (***, p < 0.001). Full article ">Figure 3
Time-of-addition analysis of BBM, FAN, and +FAN. (A) Overall scheme for Vero-E6 cells infection and treatment with BBM (10 μM), FAN (5 μM), and +FAN (5 μM); the solid gray line refers to the PEDV infection period and the dotted gray line refers to the BBM, FAN, and +FAN treatment. (B) After 12 h.p.i., the protein sample was harvested, and the PEDV-N and actin protein levels were determined by Western blotting. Full article ">Figure 4
BBM, FAN, and +FAN did not target PEDV particles directly. (A) The overall scheme for Vero-E6 cells infection and treatment with BBM (0, 2, 5, and 10 μM), FAN (0, 1, 2, and 5 μM), and +FAN (0, 1, 2, and 5 μM). PEDV, HLJBY strain (one MOI) was mixed with BBM, FAN, and +FAN for 1 h at 37 °C. Then, the mixture was diluted in 2 mL DMEM and incubated with Vero-E6. (B–D) The protein sample was harvested at 12 h.p.i., and the PEDV-N and actin protein levels were determined by Western blotting. (E) An overall scheme for PEDV infection and treatment with BBM (10 μM), FAN (5 μM), and +FAN (5 μM). The gray solid line refers to the PEDV infection period. The dotted gray line refers to the BBM, FAN, and +FAN treatments. (F) Vero-E6 cells were pretreated with BBM, FAN, and +FAN for 2 h (1 h at 37 °C and another at 4 °C), infected with PEDV, HLJBY strain (one MOI), and then treated with BBM, FAN, and +FAN for 1 h at 4 °C. Finally, the cells were washed with cold PBS to wash out the unbound virus, followed by RT-PCR assay to determine the levels of PEDV-M and actin mRNA. Full article ">Figure 5
BBM, FAN, and +FAN inhibited PEDV entry by suppressing endo-lysosome acidification. (A) The overall scheme for PEDV infection and treatment with BBM (10 μM), FAN (5 μM), and +FAN (5 μM). The gray solid line refers to the PEDV infection period. The dotted gray line refers to the BBM, FAN, and +FAN treatments. (B) Vero-E6 cells were infected with PEDV, HLJBY strain (one MOI) at 4 °C. After infection, the cells were treated with BBM, FAN, and +FAN for 2 h at 37 °C and washed thrice with citrate buffer, followed by incubation in fresh DMEM for 3 h. Finally, the protein sample was harvested, and the levels of PEDV-N and actin protein were determined by Western blotting. (C) Vero-E6 cells were infected with PEDV, HLJBY strain (one MOI) at 4 °C. After infection, the cells were treated with NH4Cl (0, 30, and 50 mM) for 2 h at 37 °C and washed thrice with citrate buffer, followed by incubation with fresh DMEM for 3 h. Finally, the protein sample was harvested, and the levels of PEDV-N and actin protein were determined by Western blotting. (D–F) The Vero-E6 cells were treated with BBM, FAN, and +FAN for 0, 1, 2, and 4 h, and then labeled with 2 μM lysosensorTM yellow/blue DND-160 for 3 min at 37 °C. The excess dye was removed with cold PBS and then transferred to DMEM. The emission ratio at 451/510 nm was measured at excitation-365 nm. The results were analyzed by Student t-test (*, p < 0.05; **, p < 0.01; ns, p > 0.05). Full article ">Figure 6
BBM, FAN, and +FAN inhibit PEDV entry by decreasing the activity of CTSL and CTSB. (A–C) The Vero-E6 cells were treated with BBM (10 μM), FAN (5 μM), and +FAN (5 μM) for 0, 1, 2, and 4 h and then labeled with the Magic Red® Cathepsin-L Assay Kit at 37 °C for 40 min. The excess dye was removed with PBS, followed by transferring it to DMEM without phenol red. The fluorescence intensity was measured at excitation-592 nm/emission-628 nm. (D–F) The Vero-E6 cells were treated with BBM (10 μM), FAN (5 μM), and +FAN (5 μM) for 0, 1, 2, and 4 h, followed by labeled with the Magic Red® Cathepsin-B Assay Kit at 37 °C for 40 min. The excess dye was removed with PBS, followed by transferring it to DMEM without phenol red. The fluorescence intensity was measured at excitation-592 nm/emission-628 nm. The results were analyzed by Student t-test (*, p < 0.05; **, p < 0.01; ***, p < 0.001). Full article ">Figure 7
Diagram showing a hypothesized antiviral mechanism of BBM, FAN, and +FAN during PEDV infection. Full article ">

20 pages, 2305 KiB

Open AccessArticle

Effectiveness of Intermittent Preventive Treatment with Sulfadoxine-Pyrimethamine in Pregnancy: Low Coverage and High Prevalence of Plasmodium falciparum dhfr-dhps Quintuple Mutants as Major Challenges in Douala, an Urban Setting in Cameroon

by Carole Else Eboumbou Moukoko, Loick Pradel Kojom Foko, Angèle Ayina, Bernard Tornyigah, Annie Rachel Epote, Ida Calixte Penda, Patricia Epee Eboumbou, Serge Bruno Ebong, Gaetan Texier, Sandrine Eveline Nsango, Lawrence Ayong, Nicaise Tuikue Ndam and Albert Same Ekobo

Pathogens 2023, 12(6), 844; https://doi.org/10.3390/pathogens12060844 - 19 Jun 2023

Cited by 5 | Viewed by 2402

Abstract

Intermittent preventive treatment in pregnancy with sulfadoxine and pyrimethamine (IPTp-SP) is a key component in the malaria control strategy implemented in Africa. The aim of this study was to determine IPTp-SP adherence and coverage, and the impact on maternal infection and birth outcomes [...] Read more.

Intermittent preventive treatment in pregnancy with sulfadoxine and pyrimethamine (IPTp-SP) is a key component in the malaria control strategy implemented in Africa. The aim of this study was to determine IPTp-SP adherence and coverage, and the impact on maternal infection and birth outcomes in the context of widespread SP resistance in the city of Douala, Cameroon. Clinical and demographic information were documented among 888 pregnant women attending 3 health facilities, from the antenatal care visit to delivery. Positive samples were genotyped for P. falciparum gene (dhfr, dhps, and k13) mutations. The overall IPTp-SP coverage (≥three doses) was 17.5%, and 5.1% received no dose. P. falciparum prevalence was 16%, with a predominance of submicroscopic infections (89.3%). Malaria infection was significantly associated with locality and history of malaria, and it was reduced among women using indoor residual spraying. Optimal doses of IPTp-SP were significantly associated with reduced infection among newborns and women (secundiparous and multiparous), but there was no impact of IPTp-SP on the newborn bodyweight. Pfdhfr-Pfdhps quintuple mutants were over-represented (IRNI-FGKAA, IRNI-AGKAA), and sextuple mutants (IRNI-AGKAS, IRNI-FGEAA, IRNI-AGKGS) were also reported. The Pfk13 gene mutations associated with artemisinin resistance were not detected. This study highlights the role of ANC in achieving optimal SP coverage in pregnant women, the mitigated impact of IPTp-SP on malaria outcomes, and the high prevalence of multiple SP-resistant P. falciparum parasites in the city of Douala that could compromise the efficacy of IPTp-SP. Full article

(This article belongs to the Section Parasitic Pathogens)

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Location of the study sites in the town of Douala, Littoral Region, Cameroon. Note: Three health facilities were included in three health districts, referred to as the Deido, Bonassama, and Nylon districts, located in Douala III district of the Littoral Region in Cameron, Central Africa Region. Full article ">Figure 2
Flow diagram of the study depicting the process of participant inclusion. Note: SP: Sulfadoxine-pyrimethamine, G6PD: glucose-6-phosphate dehydrogenase, HIV: human immunodeficiency virus, BDH: Bonassama District Hospital, DDH: Deido District Hospital, NySPMC: Nylon St Paul Maternity Clinic. Full article ">Figure 3
Association between (a) gestational age and antenatal care visits, (b) gestational age and IPTp-SP coverage, and (c) antenatal care visits and IPTp-SP coverage. Note: IPTp-SP: Intermittent preventive treatment with sulfadoxine-pyrimethamine in pregnancy. Pearson’s chi square test was used to compare percentages. Statistically significant at p-value < 0.05. Full article ">Figure 4
Proportion of peripheral P. falciparum infections among the women by comparing diagnostic methods. Note: LM: light microscopy; RDT: rapid diagnostic test; qPCR: quantitative polymerase chain reaction. * Total sample size was below 888 as results for LM, RDT, and qPCR were not available for some women during the study. Full article ">Figure 5
Anemia and its relation to malaria infection. (a) Prevalence of anemia, (b) variation of hemoglobin count by peripheral malaria infection, and (c) variation of hemoglobin count by type of peripheral malaria infection. Full article ">

13 pages, 2573 KiB

Open AccessBrief Report

Oral Epithelial Cells Expressing Low or Undetectable Levels of Human Angiotensin-Converting Enzyme 2 Are Susceptible to SARS-CoV-2 Virus Infection In Vitro

by Laith Ebraham, Chuan Xu, Annie Wang, Cyril Hernandez, Nicholas Siclari, Divino Rajah, Lewins Walter, Salvatore A. E. Marras, Sanjay Tyagi, Daniel H. Fine, Carlo Amorin Daep and Theresa L. Chang

Pathogens 2023, 12(6), 843; https://doi.org/10.3390/pathogens12060843 - 19 Jun 2023

Cited by 2 | Viewed by 2200

Abstract

The oral cavity is thought to be one of the portals for SARS-CoV-2 entry, although there is limited evidence of active oral infection by SARS-CoV-2 viruses. We assessed the capacity of SARS-CoV-2 to infect and replicate in oral epithelial cells. Oral gingival epithelial [...] Read more.

The oral cavity is thought to be one of the portals for SARS-CoV-2 entry, although there is limited evidence of active oral infection by SARS-CoV-2 viruses. We assessed the capacity of SARS-CoV-2 to infect and replicate in oral epithelial cells. Oral gingival epithelial cells (hTERT TIGKs), salivary gland epithelial cells (A-253), and oral buccal epithelial cells (TR146), which occupy different regions of the oral cavity, were challenged with replication-competent SARS-CoV-2 viruses and with pseudo-typed viruses expressing SARS-CoV-2 spike proteins. All oral epithelial cells expressing undetectable or low levels of human angiotensin-converting enzyme 2 (hACE2) but high levels of the alternative receptor CD147 were susceptible to SARS-CoV-2 infection. Distinct viral dynamics were seen in hTERT TIGKs compared to A-253 and TR146 cells. For example, levels of viral transcripts were sustained in hTERT TIGKs but were significantly decreased in A-253 and TR146 cells on day 3 after infection. Analysis of oral epithelial cells infected by replication-competent SARS-CoV-2 viruses expressing GFP showed that the GFP signal and SARS-CoV-2 mRNAs were not evenly distributed. Furthermore, we found cumulative SARS-CoV-2 RNAs from released viruses in the media from oral epithelial cells on day 1 and day 2 after infection, indicating productive viral infection. Taken together, our results demonstrated that oral epithelial cells were susceptible to SARS-CoV-2 viruses despite low or undetectable levels of hACE2, suggesting that alternative receptors contribute to SARS-CoV-2 infection and may be considered for the development of future vaccines and therapeutics. Full article

(This article belongs to the Collection SARS-CoV Infections)

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12 pages, 2805 KiB

Open AccessArticle

Discovery of Terpenes as Novel HCV NS5B Polymerase Inhibitors via Molecular Docking

by Tomasz M. Karpiński, Marcin Ożarowski, Pedro J. Silva, Mark Stasiewicz, Rahat Alam and Abdus Samad

Pathogens 2023, 12(6), 842; https://doi.org/10.3390/pathogens12060842 - 18 Jun 2023

Cited by 1 | Viewed by 2079

Abstract

Hepatitis C virus (HCV) is a dangerous virus that is responsible for a large number of infections and deaths worldwide. In the treatment of HCV, it is important that the drugs are effective and do not have additional hepatotoxic effects. The aim of [...] Read more.

Hepatitis C virus (HCV) is a dangerous virus that is responsible for a large number of infections and deaths worldwide. In the treatment of HCV, it is important that the drugs are effective and do not have additional hepatotoxic effects. The aim of this study was to test the in silico activity of 1893 terpenes against the HCV NS5B polymerase (PDB-ID: 3FQK). Two drugs, sofosbuvir and dasabuvir, were used as controls. The GOLD software (CCDC) and InstaDock were used for docking. By using the results obtained from PLP.Fitness (GOLD), pKi, and binding free energy (InstaDock), nine terpenes were finally selected based on their scores. The drug-likeness properties were calculated using Lipinski’s rule of five. The ADMET values were studied using SwissADME and pkCSM servers. Ultimately, it was shown that nine terpenes have better docking results than sofosbuvir and dasabuvir. These were gniditrin, mulberrofuran G, cochlearine A, ingenol dibenzoate, mulberrofuran G, isogemichalcone C, pawhuskin B, 3-cinnamyl-4-oxoretinoic acid, DTXSID501019279, and mezerein. Each docked complex was submitted to 150 ns-long molecular dynamics simulations to ascertain the binding stability. The results show that mulberrofuran G, cochlearine A, and both stereoisomers of pawhuskin B form very stable interactions with the active site region where the reaction product should form and are, therefore, good candidates for use as effective competitive inhibitors. The other compounds identified in the docking screen either afford extremely weak (or even hardly any) binding (such as ingenol dibenzoate, gniditrin, and mezerein) or must first undergo preliminary movements in the active site before attaining their stable binding conformations, in a process which may take from 60 to 80 ns (for DTXSID501019279, 3-cinnamyl-4-oxoretinoic acid or isogemichalcone C). Full article

(This article belongs to the Special Issue Advances in HCV Research)

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11 pages, 559 KiB

Open AccessArticle

Clinical Use of Intravenous Fosfomycin in Critical Care Patients in Taiwan

by Tzu-Ting Chen, Yun-Fu Chang and Yea-Chwen Wu

Pathogens 2023, 12(6), 841; https://doi.org/10.3390/pathogens12060841 - 18 Jun 2023

Cited by 2 | Viewed by 3094

Abstract

This retrospective study aimed to evaluate the clinical use and side effects of fosfomycin in critically ill patients in Taiwan. Forty-two patients (mean age, 69.9 years; female, 69%) who received fosfomycin were included from a teaching hospital in Taiwan from January 2021 to [...] Read more.

This retrospective study aimed to evaluate the clinical use and side effects of fosfomycin in critically ill patients in Taiwan. Forty-two patients (mean age, 69.9 years; female, 69%) who received fosfomycin were included from a teaching hospital in Taiwan from January 2021 to December 2021. We analyzed the prescription pattern of intravenous fosfomycin and evaluated patient safety profiles, clinical successes, and microbiological cure rates. The main indication was urinary tract infections (35.6%), and the most frequently identified pathogen was Escherichia coli (18.2%). The overall clinical success was 83.4%, with one multidrug-resistant pathogen isolated from eight patients (19.0%). The average dose of fosfomycin given was 11.1 ± 5.2 g/day. The average duration of therapy was 8.7 ± 5.9 days, with a median duration of 8 days, where fosfomycin was mostly (83.3%) given in combination. Fosfomycin was given 12 hourly to a maximum number (47.6%) of cases. The incidence rates of adverse drug reactions (hypernatremia and hypokalemia) were 33.33% (14/42) and 28.57% (12/42), respectively. The overall survival rate was 73.8%. Intravenous fosfomycin may be an effective and safe antibiotic to use in combination with other drugs for empirical broad-spectrum or highly suspected multidrug-resistant infections in critically ill patients. Full article

(This article belongs to the Section Bacterial Pathogens)

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19 pages, 1627 KiB

Open AccessReview

What about the Cytoskeletal and Related Proteins of Tapeworms in the Host’s Immune Response? An Integrative Overview

by Diana G. Ríos-Valencia, Javier Ambrosio, Rocío Tirado-Mendoza, Julio César Carrero and Juan Pedro Laclette

Pathogens 2023, 12(6), 840; https://doi.org/10.3390/pathogens12060840 - 18 Jun 2023

Viewed by 2864

Abstract

Recent advances have increased our understanding of the molecular machinery in the cytoskeleton of mammalian cells, in contrast to the case of tapeworm parasites, where cytoskeleton remains poorly characterized. The pertinence of a better knowledge of the tapeworm cytoskeleton is linked to the [...] Read more.

Recent advances have increased our understanding of the molecular machinery in the cytoskeleton of mammalian cells, in contrast to the case of tapeworm parasites, where cytoskeleton remains poorly characterized. The pertinence of a better knowledge of the tapeworm cytoskeleton is linked to the medical importance of these parasitic diseases in humans and animal stock. Moreover, its study could offer new possibilities for the development of more effective anti-parasitic drugs, as well as better strategies for their surveillance, prevention, and control. In the present review, we compile the results of recent experiments on the cytoskeleton of these parasites and analyze how these novel findings might trigger the development of new drugs or the redesign of those currently used in addition to supporting their use as biomarkers in cutting-edge diagnostic tests. Full article

(This article belongs to the Special Issue Advances in the Immunobiology of Parasitic Diseases Volume II)

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23 pages, 2419 KiB

Open AccessReview

Virulence Factors of Mycobacterium tuberculosis as Modulators of Cell Death Mechanisms

by Lucero A. Ramon-Luing, Yadira Palacios, Andy Ruiz, Norma A. Téllez-Navarrete and Leslie Chavez-Galan

Pathogens 2023, 12(6), 839; https://doi.org/10.3390/pathogens12060839 - 18 Jun 2023

Cited by 17 | Viewed by 13046

Abstract

Mycobacterium tuberculosis (Mtb) modulates diverse cell death pathways to escape the host immune responses and favor its dissemination, a complex process of interest in pathogenesis-related studies. The main virulence factors of Mtb that alter cell death pathways are classified according to their origin [...] Read more.

Mycobacterium tuberculosis (Mtb) modulates diverse cell death pathways to escape the host immune responses and favor its dissemination, a complex process of interest in pathogenesis-related studies. The main virulence factors of Mtb that alter cell death pathways are classified according to their origin as either non-protein (for instance, lipomannan) or protein (such as the PE family and ESX secretion system). The 38 kDa lipoprotein, ESAT-6 (early antigen-secreted protein 6 kDa), and another secreted protein, tuberculosis necrotizing toxin (TNT), induces necroptosis, thereby allowing mycobacteria to survive inside the cell. The inhibition of pyroptosis by blocking inflammasome activation by Zmp1 and PknF is another pathway that aids the intracellular replication of Mtb. Autophagy inhibition is another mechanism that allows Mtb to escape the immune response. The enhanced intracellular survival (Eis) protein, other proteins, such as ESX-1, SecA2, SapM, PE6, and certain microRNAs, also facilitate Mtb host immune escape process. In summary, Mtb affects the microenvironment of cell death to avoid an effective immune response and facilitate its spread. A thorough study of these pathways would help identify therapeutic targets to prevent the survival of mycobacteria in the host. Full article

(This article belongs to the Section Immunological Responses and Immune Defense Mechanisms)

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Major virulent factors of Mtb involved in cell death mechanisms. (a) Mycobacterial virulence proteins are mainly secreted through one of the essential secretion systems, ESX. ESX1, ESX3, and ESX5 are localized across the membrane, where proteins, such as ESAT-6, CFP-10, PE_PGRS, PtpA, SapM, PknG, and PknE, are delivered (left). (b) Non-proteins are glycolipids and phospholipids forming mycobacterial membrane structures. LAM (lipoarabinomannan), ManLAM (mannose-capped LAM), PDIM (phthiocerol dimycocerosate), and PIMs (Phosphatidyl-myo-inositol mannosides) are inserted in the cell wall (right). TDM, trehalose mono, and di mycolate; PGL, phenolic glycolipid. Full article ">Figure 2
Mycobacterium tuberculosis and apoptosis modulation. The mycobacteria or its virulence factors may modulate apoptosis, both intrinsic and extrinsic pathways at different levels, as inductors (red arrows) or inhibitors (black inhibitors). (a) Apoptosis may be detonated via TNF and FasL impacting initiator caspases-8 and -9 and effector caspases-3 and -7. (b) The intrinsic pathway also may control mycobacteria infection at the mitochondria level, cytochrome c released, and apoptosome formation by activating caspases-9 and -3. (c) TNF death signal may be blocked at DISC formation and caspase-8 activation. (d) The proapoptotic protein BAX may be down-regulated with the H37Ra strain. (e) Mycobacteria may stabilize the anti-apoptotic Bcl-2. (f) Up-regulation at the gene level of FasL and caspases may be done during mycobacteria infection; (g) down-regulation of IL-12 expression and TNF has also been reported. Full article ">Figure 3
Mycobacterium tuberculosis and the necrotic-like cell death modulation. The mycobacteria or its virulence factors may modulate pyroptosis, necroptosis, and ferroptosis pathways at different levels as inducers (red arrows) or inhibitors (black inhibitors). For example, Mtb through ESAT-6, LpqH activates inflammasome, favoring pyroptosis, while Zmp1 and PknF inhibit it. The Mtb ESX-1 secretion system, secreted protein ESAT-6, TNT, and PDIM lipid induce necroptosis. Meanwhile, multiple factors inhibit or activate ferroptosis, including the HO-1 enzyme, the SOCS1 protein, and the PI3K/Akt/mTORC1 signaling pathway, which act at different levels and points regulating the cell death pathway. PtpA favors ferroptosis by inhibiting GPX4 expression, a ferroptosis regulator. Full article ">Figure 4
Overview of cell death pathways modulated by Mtb through their virulence factors. Mtb can use its various virulence factors as inductors (red arrows) or inhibitors (black inhibitors) of diverse cell death mechanisms to orchestrate the infection process; as well, it allows it to disseminate and replicate for its survival. Full article ">

23 pages, 1287 KiB

Open AccessEditor’s ChoiceReview

Metallic Nanoparticles and Core-Shell Nanosystems in the Treatment, Diagnosis, and Prevention of Parasitic Diseases

by Grzegorz Król, Kamila Fortunka, Michał Majchrzak, Ewelina Piktel, Paulina Paprocka, Angelika Mańkowska, Agata Lesiak, Maciej Karasiński, Agnieszka Strzelecka, Bonita Durnaś and Robert Bucki

Pathogens 2023, 12(6), 838; https://doi.org/10.3390/pathogens12060838 - 17 Jun 2023

Cited by 9 | Viewed by 3235

Abstract

The usage of nanotechnology in the fight against parasitic diseases is in the early stages of development, but it brings hopes that this new field will provide a solution to target the early stages of parasitosis, compensate for the lack of vaccines for [...] Read more.

The usage of nanotechnology in the fight against parasitic diseases is in the early stages of development, but it brings hopes that this new field will provide a solution to target the early stages of parasitosis, compensate for the lack of vaccines for most parasitic diseases, and also provide new treatment options for diseases in which parasites show increased resistance to current drugs. The huge physicochemical diversity of nanomaterials developed so far, mainly for antibacterial and anti-cancer therapies, requires additional studies to determine their antiparasitic potential. When designing metallic nanoparticles (MeNPs) and specific nanosystems, such as complexes of MeNPs, with the shell of attached drugs, several physicochemical properties need to be considered. The most important are: size, shape, surface charge, type of surfactants that control their dispersion, and shell molecules that should assure specific molecular interaction with targeted molecules of parasites’ cells. Therefore, it can be expected that the development of antiparasitic drugs using strategies provided by nanotechnology and the use of nanomaterials for diagnostic purposes will soon provide new and effective methods of antiparasitic therapy and effective diagnostic tools that will improve the prevention and reduce the morbidity and mortality caused by these diseases. Full article

(This article belongs to the Section Parasitic Pathogens)

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11 pages, 294 KiB

Open AccessArticle

Prevalence, Serotypes, Antimicrobial Resistance and Biofilm-Forming Ability of Listeria monocytogenes Isolated from Bulk-Tank Bovine Milk in Northern Greece

by Apostolos S. Angelidis, Afroditi S. Grammenou, Charalampos Kotzamanidis, Nektarios D. Giadinis, Antonios G. Zdragas and Daniel Sergelidis

Pathogens 2023, 12(6), 837; https://doi.org/10.3390/pathogens12060837 - 17 Jun 2023

Cited by 7 | Viewed by 1843

Abstract

The prevalence of Listeria monocytogenes in bovine bulk-tank milk (BTM) in Greece has not been previously investigated. The aim of the study was to estimate the prevalence of L. monocytogenes in bovine BTM in Greece and to characterize the isolates in terms of [...] Read more.

The prevalence of Listeria monocytogenes in bovine bulk-tank milk (BTM) in Greece has not been previously investigated. The aim of the study was to estimate the prevalence of L. monocytogenes in bovine BTM in Greece and to characterize the isolates in terms of carriage of genes encoding for pathogenic determinants, assess the isolates’ biofilm-forming ability and determine their susceptibility against 12 antimicrobials. Samples (n = 138) of bovine BTM were obtained from farms located throughout Northern Greece and were analyzed qualitatively and quantitatively for L. monocytogenes. Five samples (3.6%) tested positive for L. monocytogenes. The pathogen’s populations in these positive samples were below 5 CFU/mL. Most isolates belonged to the molecular serogroup “1/2a, 3a”. All isolates carried the virulence genes inlA, inlC, inlJ, iap, plcA and hlyA, but actA was detected in only three isolates. The isolates displayed weak to moderate biofilm-forming ability and distinct antimicrobial resistance profiles. All isolates were characterized as multidrug resistant, with resistance to penicillin and clindamycin being a common feature. Considering that L. monocytogenes constitutes a serious public health threat, the key findings of the study, related to the carriage of virulence genes and multidrug resistance, highlight the importance of continued monitoring of the pathogen in farm animals. Full article

(This article belongs to the Section Bacterial Pathogens)

15 pages, 3251 KiB

Open AccessArticle

Prevalence of Enterococcus spp. and the Whole-Genome Characteristics of Enterococcus faecium and Enterococcus faecalis Strains Isolated from Free-Living Birds in Poland

by Renata Kwit, Magdalena Zając, Aleksandra Śmiałowska-Węglińska, Magdalena Skarżyńska, Arkadiusz Bomba, Anna Lalak, Ewelina Skrzypiec, Dominika Wojdat, Weronika Koza, Emilia Mikos-Wojewoda, Paulina Pasim, Milena Skóra, Marcin Polak, Jarosław Wiącek and Dariusz Wasyl

Pathogens 2023, 12(6), 836; https://doi.org/10.3390/pathogens12060836 - 16 Jun 2023

Cited by 8 | Viewed by 2919

Abstract

Enterococci as opportunistic bacteria are important for human health. Due to the prevalence and ease of acquisition and transfer of their genes, they are an excellent indicator of environmental contamination and the spread of antimicrobial resistance. The aim of the study was to [...] Read more.

Enterococci as opportunistic bacteria are important for human health. Due to the prevalence and ease of acquisition and transfer of their genes, they are an excellent indicator of environmental contamination and the spread of antimicrobial resistance. The aim of the study was to assess the prevalence of Enterococcus spp. in wild birds in Poland, determination of antimicrobial susceptibility and WGS analysis of Enterococcus (E.) faecium and E. faecalis. For this purpose, 138 samples from various species of free-living birds were tested, with 66.7% positive results. Fourteen species were detected, with E. faecalis being the most common, followed by E. casseliflavus and E. hirae. In antimicrobial susceptibility testing, 10.0% of E. faecalis and 50.0% of E. faecium showed resistance to one antimicrobial agent, in addition the MDR phenotype which was found in one E. faecium. The most common resistance phenotype included tetracycline and quinupristin/dalfopristin. The WGS analysis confirmed the significant advantage of the virulence gene diversity of E. faecalis strains over E. faecium. In addition, plasmid replicons were found in 42.0% of E. faecalis and 80.0% of E. faecium. The obtained results confirm free-living birds can be a reservoir of Enterococcus spp. with a considerable zoonotic potential. Full article

(This article belongs to the Special Issue Surveillance of Zoonotic Pathogens Carried by Wildlife)

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11 pages, 1176 KiB

Open AccessArticle

Neutralizing Antibodies against the SARS-CoV-2 Ancestral Strain and Omicron BA.1 Subvariant in Dogs and Cats in Mexico

by Freddy Dehesa-Canseco, Roxana Pastrana-Unzueta, Nadia Carrillo-Guzmán, Francisco Liljehult-Fuentes, Juan Diego Pérez-De la Rosa, Humberto Ramírez-Mendoza, Jose Guillermo Estrada-Franco, Roberto Navarro-López, Jesús Hernández and Mario Solís-Hernández

Pathogens 2023, 12(6), 835; https://doi.org/10.3390/pathogens12060835 - 16 Jun 2023

Cited by 3 | Viewed by 1745

Abstract

SARS-CoV-2 mainly affects humans; however, it is important to monitor the infection of companion and wild animals as possible reservoirs of this virus. In this sense, seroprevalence studies in companion animals, such as dogs and cats, provide important information about the epidemiology of [...] Read more.

SARS-CoV-2 mainly affects humans; however, it is important to monitor the infection of companion and wild animals as possible reservoirs of this virus. In this sense, seroprevalence studies in companion animals, such as dogs and cats, provide important information about the epidemiology of SARS-CoV-2. This study aimed to evaluate the seroprevalence of neutralizing antibodies (nAbs) against the ancestral strain and the Omicron BA.1 subvariant in dogs and cats in Mexico. Six hundred and two samples were obtained from dogs (n = 574) and cats (n = 28). These samples were collected from the end of 2020 to December 2021 from different regions of Mexico. The presence of nAbs was evaluated using a plaque reduction neutralization test (PRNT) and microneutralization (MN) assays. The results showed that 14.2% of cats and 1.5% of dogs presented nAbs against the ancestral strain of SARS-CoV-2. The analysis of nAbs against Omicron BA.1 in cats showed the same percentage of positive animals but a reduced titer. In dogs, 1.2% showed nAbs against Omicron BA.1. These results indicate that nAbs were more frequent in cats than in dogs and that these nAbs have a lower capacity to neutralize the subvariant Omicron BA.1. Full article

(This article belongs to the Topic Immune Response to Zoonotic Pathogens)

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12 pages, 1185 KiB

Open AccessArticle

Growth of V. parahaemolyticus in Tropical Blacklip Rock Oysters

by Anna C. Padovan, Alison R. Turnbull, Samantha J. Nowland, Matthew W. J. Osborne, Mirjam Kaestli, Justin R. Seymour and Karen S. Gibb

Pathogens 2023, 12(6), 834; https://doi.org/10.3390/pathogens12060834 - 16 Jun 2023

Cited by 3 | Viewed by 2256

Abstract

The opportunistic pathogen Vibrio parahaemolyticus poses a significant food safety risk worldwide, and understanding its growth in commercially cultivated oysters, especially at temperatures likely to be encountered post-harvest, provides essential information to provide the safe supply of oysters. The Blacklip Rock Oyster (BRO) [...] Read more.

The opportunistic pathogen Vibrio parahaemolyticus poses a significant food safety risk worldwide, and understanding its growth in commercially cultivated oysters, especially at temperatures likely to be encountered post-harvest, provides essential information to provide the safe supply of oysters. The Blacklip Rock Oyster (BRO) is an emerging commercial species in tropical northern Australia and as a warm water species, it is potentially exposed to Vibrio spp. In order to determine the growth characteristics of Vibrio parahaemolyticus in BRO post-harvest, four V. parahaemolyticus strains isolated from oysters were injected into BROs and the level of V. parahaemolyticus was measured at different time points in oysters stored at four temperatures. Estimated growth rates were −0.001, 0.003, 0.032, and 0.047 log₁₀ CFU/h at 4 °C, 13 °C, 18 °C, and 25 °C, respectively. The highest maximum population density of 5.31 log₁₀ CFU/g was achieved at 18 °C after 116 h. There was no growth of V. parahaemolyticus at 4 °C, slow growth at 13 °C, but notably, growth occurred at 18 °C and 25 °C. Vibrio parahaemolyticus growth at 18 °C and 25 °C was not significantly different from each other but were significantly higher than at 13 °C (polynomial GLM model, interaction terms between time and temperature groups p < 0.05). Results support the safe storage of BROs at both 4 °C and 13 °C. This V. parahaemolyticus growth data will inform regulators and assist the Australian oyster industry to develop guidelines for BRO storage and transport to maximise product quality and safety. Full article

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Growth profiles of Vibrio parahaemolyticus in Blacklip Rock Oysters stored at 4 °C, 13 °C, 18 °C, and 25 °C. Points indicate the averages of five replicates, bars are the standard deviation, and the lines indicate fitted curves. The last sample at 25 °C consisted of only one replicate. Full article ">Figure 2
Estimated Vibrio parahaemolyticus growth in Blacklip Rock Oysters at each temperature after 48 and 72 h. Black line is the estimated average counts and the grey area is the 95% confidence interval based on a polynomial generalised linear model. Starting concentrations of V. parahaemolyticus injected into the oysters were 2.0 × 107 CFU/mL for the 4 °C and 13 °C experiment and 4.2 × 105 CFU/mL for the 18 °C and 25 °C experiment. Full article ">Figure 3
Vibrio parahaemolyticus concentrations in Blacklip Rock Oyster injected with filtered sterile seawater and stored at 4 °C, 13 °C, 18 °C, and 25 °C. Full article ">Figure 4
Growth rates of Vibrio parahaemolyticus in different oyster species at different temperatures [<a href="#B19-pathogens-12-00834" class="html-bibr">19</a>,<a href="#B22-pathogens-12-00834" class="html-bibr">22</a>,<a href="#B23-pathogens-12-00834" class="html-bibr">23</a>,<a href="#B24-pathogens-12-00834" class="html-bibr">24</a>,<a href="#B25-pathogens-12-00834" class="html-bibr">25</a>]. Full article ">

9 pages, 1172 KiB

Open AccessCommunication

Canine Distemper Virus Infection in the Free-Living Wild Canines, the Red Fox (Vulpes vulpes) and Jackal (Canis aureus moreoticus), in Croatia

by Jelena Prpić, Ivana Lojkić, Tomislav Keros, Nina Krešić and Lorena Jemeršić

Pathogens 2023, 12(6), 833; https://doi.org/10.3390/pathogens12060833 - 15 Jun 2023

Cited by 5 | Viewed by 2303

Abstract

The canine distemper virus (CDV), a paramyxovirus that is closely related to the human measles virus and rinderpest virus of cattle, is a highly contagious viral disease in dogs and wild carnivores worldwide. CDV represents a serious threat to domestic and wild animals, [...] Read more.

The canine distemper virus (CDV), a paramyxovirus that is closely related to the human measles virus and rinderpest virus of cattle, is a highly contagious viral disease in dogs and wild carnivores worldwide. CDV represents a serious threat to domestic and wild animals, especially to the conservation of endangered wild carnivores. Our study aims to investigate the occurrence of CDV in free-living wild canines in Croatia. For this purpose, 176 red foxes and 24 jackal brain samples collected in the frame of the active surveillance of rabies during winter 2021/2022 were tested. This study provided the first comprehensive overview of the prevalence and spatial distribution of CDV in the wildlife of Croatia, including the molecular phylogenetic analysis of the H gene sequence of field CDV strains circulating in red fox and jackal populations of Croatia. The molecular characterization of hemagglutinin gene genomic regions confirmed the phylogenetic clustering of obtained sequences into the Europa 1 genotype. The obtained CDV red fox sequences were mutually very similar (97.60%). This study indicates the high genetic similarity of Croatian CDV red fox sequences and CDV red fox sequences from Italy and Germany, badger sequences from Germany, polecat sequences from Hungary, and dog sequences from Hungary and Germany. Full article

(This article belongs to the Collection Feature Papers in Viral Pathogens)

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17 pages, 2814 KiB

Open AccessArticle

The Eradication of Helicobacter pylori Was Significantly Associated with Compositional Patterns of Orointestinal Axis Microbiota

by Sally Ali Tawfik, Marwa Azab, Mohammed Ramadan, Sarah Shabayek, Ali Abdellah, Sultan S. Al Thagfan and Mohammed Salah

Pathogens 2023, 12(6), 832; https://doi.org/10.3390/pathogens12060832 - 15 Jun 2023

Cited by 5 | Viewed by 2285

Abstract

Background: Helicobacter pylori (H. pylori) is significantly linked to various diseases that seriously impact human health, such as gastric ulcers, chronic gastritis and gastric adenocarcinoma. Methods: The compositional shifts in bacterial communities of the orointestinal axis were surveyed pre/post-eradication of H. [...] Read more.

Background: Helicobacter pylori (H. pylori) is significantly linked to various diseases that seriously impact human health, such as gastric ulcers, chronic gastritis and gastric adenocarcinoma. Methods: The compositional shifts in bacterial communities of the orointestinal axis were surveyed pre/post-eradication of H. pylori. In total, 60 samples, including stool and salivary specimens, were collected from 15 H. pylori-positive individuals (HPP) before beginning and 2 months after receiving the eradication therapy. The V3-V4 regions of the 16S rRNA gene were sequenced using MiSeq. Results: Overall, oral microbiomes were collectively more diverse than the gut microbiomes (Kruskal–Wallis; p = 3.69 × 10⁻⁵). Notably, the eradication of H. pylori was associated with a significant reduction in the bacterial diversity along the orointestinal axis (Wilcoxon rank sum test; p = 6.38 × 10⁻³). Interestingly, the oral microbiome of HPP showed a positive correlation between Proteobacteria and Fusobacteria, in addition to a significant predominance of Streptococcus, in addition to Eubacterium_eligens, Haemophilus, Ruminococcaceae, Actinomyces and Staphylococcus. On the other hand, Fusobacterium, Veillonella, Catenibacterium, Neisseria and Prevotella were significantly enriched upon eradication of H. pylori. Generally, Bacteroidetes and Fusobacteria positively coexisted during H. pylori infection along the orointestinal axis (r = 0.67; p = 0.0006). The eradication of H. pylori was positively linked to two distinctive orotypes (O3 and O4). Orotype O4 was characterized by a robust abundance of Veillonella and Fusobacteria. The gut microbiomes during H. pylori infection showed a remarkable predominance of Clostridium_sensu_stricto_1 and Escherichia_Shigella. Likewise, Bifidobacterium and Faecalibacterium were significantly enriched upon eradication of H. pylori. Conclusions: Finally, the impact of eradication therapy clearly existed on the representation of certain genera, especially in the oral microbiome, which requires particular concern in order to counteract and limit their subsequent threats. Full article

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Phylum level analysis of oral and gut microbiota. (A) Bar charts illustrated the relative abundance of the major phyla in the oral and gut microbiome before and after eradication therapy of subjects. The X-axis represents the relative abundance. The Y- axis defined the study groups. Corrplots, based on the Spearman correlation coefficient, highlight the association between the main phyla: (B,C) represent the association between dominant phyla in oral microbiomes pre/post eradication of H. pylori. (D,E) define the correlation between the main phyla of gut microbiomes before and after receiving the treatment. (F,G) illustrate the association between the major phyla in the microbiomes of the orointestinal axis during and after the eradication of H. pylori. Full article ">Figure 2
Bacterial diversity measurements of orointestinal axis microbiomes. Alpha diversity indices of gut microbiomes illustrated in (A) and (B) panels: Box plots define the bacterial diversity in terms of richness (the number of observed species) and evenness (Shannon diversity index). The X-axis defines the study groups, and the Y-axis denotes the alpha diversity indices. The line in each box indicates the median, the boxes define the interquartile range (IQR) between the 25th and 75th percentile, and the whisker delimits the range. The nonparametric Wilcoxon rank-sum test was employed to identify the statistical significance of pairwise comparisons. Significant differences were indicated with either * (p < 0.05), ** (p < 0.01) or *** (p < 0.001). (C) panel represented PCoA two-dimensional graph of oral and gut microbial community membership before and after eradication therapy (axis 1 = 35.4%; axis 2 = 8.2%). Colors represented the four groups based on before and after treatment. Purple- and blue-colored balls resembled oral samples before and after treatment, respectively. Green- and pink-colored balls resembled stool samples before and after treatment, respectively. Ellipses indicate significant clustering according to site and treatment at (p-value < 0.001, PERMANOVA). Full article ">Figure 3
The genus level-based analysis of gut microbiomes associated with the orointestinal axis. (a) Box plots denote the relative abundance and differences in mean proportions with 95% confidence intervals. (b) The colored boxes describe the core genera of gut and oral microbiomes. (c) DESEQ2 was implemented to identify the significantly represented genera between the studied groups. The significant differences were represented either * (p < 0.05), ** (p < 0.01) or *** (p < 0.001). (d) LEfSe was performed to define the Candidate biomarkers for the studied groups, and the numbers indicate LDA scores. Full article ">Figure 4
Corrplots based on the Spearman correlation coefficient highlighting the association between the dominant genera: (A,B) demonstrate the association between the dominant genera in oral microbiomes pre/post eradication of H. pylori. (C,D) define the correlation between the main genera of gut microbiomes before and after receiving the treatment. (E,F) represent the association between the major genera in the microbiomes of the orointestinal axis during and after the eradication of H. pylori. Full article ">

21 pages, 2459 KiB

Open AccessArticle

Upregulation of Neuropilin-1 Inhibits HTLV-1 Infection

by Wesley Kendle, Kimson Hoang, Erica Korleski, Amanda R. Panfil, Nicholas Polakowski and Isabelle Lemasson

Pathogens 2023, 12(6), 831; https://doi.org/10.3390/pathogens12060831 - 15 Jun 2023

Viewed by 2097

Abstract

Infection with human T-cell leukemia virus type 1 (HTLV-1) can produce a spectrum of pathological effects ranging from inflammatory disorders to leukemia. In vivo, HTLV-1 predominantly infects CD4⁺ T-cells. Infectious spread within this population involves the transfer of HTLV-1 virus particles from [...] Read more.

Infection with human T-cell leukemia virus type 1 (HTLV-1) can produce a spectrum of pathological effects ranging from inflammatory disorders to leukemia. In vivo, HTLV-1 predominantly infects CD4⁺ T-cells. Infectious spread within this population involves the transfer of HTLV-1 virus particles from infected cells to target cells only upon cell-to-cell contact. The viral protein, HBZ, was found to enhance HTLV-1 infection through transcriptional activation of ICAM1 and MYOF, two genes that facilitate viral infection. In this study, we found that HBZ upregulates the transcription of COL4A1, GEM, and NRP1. COL4A1 and GEM are genes involved in viral infection, while NRP1, which encodes neuropilin 1 (Nrp1), serves as an HTLV-1 receptor on target cells but has no reported function on HTLV-1-infected cells. With a focus on Nrp1, cumulative results from chromatin immunoprecipitation assays and analyses of HBZ mutants support a model in which HBZ upregulates NRP1 transcription by augmenting recruitment of Jun proteins to an enhancer downstream of the gene. Results from in vitro infection assays demonstrate that Nrp1 expressed on HTLV-1-infected cells inhibits viral infection. Nrp1 was found to be incorporated into HTLV-1 virions, and deletion of its ectodomain removed the inhibitory effect. These results suggest that inhibition of HTLV-1 infection by Nrp1 is caused by the ectodomain of Nrp1 extended from virus particles, which may inhibit the binding of virus particles to target cells. While HBZ has been found to enhance HTLV-1 infection using cell-based models, there may be certain circumstances in which activation of Nrp1 expression negatively impacts viral infection, which is discussed. Full article

(This article belongs to the Special Issue New Directions in HTLV-1 Research)

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11 pages, 2684 KiB

Open AccessArticle

The Sarcoptic Mange in Maned Wolf (Chrysocyon brachyurus): Mapping an Emerging Disease in the Largest South American Canid

by Flávia Fiori, Rogério Cunha de Paula, Pedro Enrique Navas-Suárez, Ricardo Luiz Pires Boulhosa and Ricardo Augusto Dias

Pathogens 2023, 12(6), 830; https://doi.org/10.3390/pathogens12060830 - 15 Jun 2023

Cited by 5 | Viewed by 3710

Abstract

The maned wolf (Chrysocyon brachyurus) is the largest South American canid. In Brazil, as in other countries, it is considered an endangered species. Habitat loss, landscape changes, hunting, and roadkill are the main threats to this species. In addition, invasive diseases [...] Read more.

The maned wolf (Chrysocyon brachyurus) is the largest South American canid. In Brazil, as in other countries, it is considered an endangered species. Habitat loss, landscape changes, hunting, and roadkill are the main threats to this species. In addition, invasive diseases of domestic animals are considered to be an emerging threat to the maned wolf, where parasitic diseases are relevant. Sarcoptic mange is a skin disease caused by the mite Sarcoptes scabiei. This disease is currently almost globally distributed, with a remarkable host diversity. In Brazil, reports of sarcoptic mange in wildlife include several species, both wild and captive. However, the impact of this disease on wildlife is unknown. At the time of writing, there is only one published report of sarcoptic mange in maned wolves. This study sheds light on the occurrence of sarcoptic mange in free-ranging maned wolves in their natural range. A total of 52 cases (suspected and confirmed) of sarcoptic mange were identified through social media review, camera trapping, chemical immobilization and sample collection. These cases were distributed in southeastern Brazil, in the states of São Paulo (n = 34), Minas Gerais (n = 17), and Rio de Janeiro (n = 1), demonstrating a rapid and widespread spread of this disease, although it still only occurs in part of the species’ range. We expect that these results will help to subsidize future actions relevant to the control of this emerging disease. Full article

(This article belongs to the Special Issue Emerging Infections in Domestic Animals)

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11 pages, 330 KiB

Open AccessEditor’s ChoiceArticle

Small Ruminant Lentivirus Infection in Sheep and Goats in North Portugal: Seroprevalence and Risk Factors

by João Jacob-Ferreira, Ana Cláudia Coelho, Ana Grau Vila, Delia Lacasta and Hélder Quintas

Pathogens 2023, 12(6), 829; https://doi.org/10.3390/pathogens12060829 - 14 Jun 2023

Cited by 1 | Viewed by 2595

Abstract

Small ruminant lentiviruses (SRLVs) are transmitted among ovine and caprine species. This disease is a severe problem for small ruminant production, not only for animals’ well-being but also for flocks’ efficiency. The main aim of this research was to quantify the seroprevalence and [...] Read more.

Small ruminant lentiviruses (SRLVs) are transmitted among ovine and caprine species. This disease is a severe problem for small ruminant production, not only for animals’ well-being but also for flocks’ efficiency. The main aim of this research was to quantify the seroprevalence and associated risk factors for SRLV infection in the northern region of Portugal. Samples were collected from a total of 150 flocks, of which 129 (86.0%; 95% CI: 80.67%–91.33%) had at least one seropositive animal. Out of 2607 individual blood samples, 1074 (41.2%) were positive for SRLVs. Risk factors associated with SRLV infection were species (caprine), age (>2 years old), flock size (>100 animals), production system (intensive), food production system (milk), type of activity (professional), participation in livestock competitions (yes), replacement young ewe bought (yes), and natural feeding management (yes). This knowledge empowers the implementation of effective preventive measures. Overall, biosecurity measures should be promoted and implemented with the main aim of reducing viral transmission and reducing the prevalence of this disease. We recognise that government authorities should promote and audit voluntary control and eradication programs in small ruminant flocks in the region studied. Full article

(This article belongs to the Special Issue Women’s Special Issue Series: Pathogens)

12 pages, 842 KiB

Open AccessArticle

Topical Bacteriophage Therapy for Staphylococcal Superficial Pyoderma in Horses: A Double-Blind, Placebo-Controlled Pilot Study

by Kalie Marshall and Rosanna Marsella

Pathogens 2023, 12(6), 828; https://doi.org/10.3390/pathogens12060828 - 14 Jun 2023

Cited by 3 | Viewed by 1782

Abstract

Increased antimicrobial resistance highlights the need for alternatives to antibiotics. Bacteriophages, which are benign viruses that kill bacteria, are promising. We studied the efficacy of topical bacteriophages for treating equine staphylococcal superficial pyodermas. Eight Staphylococcus aureus isolates were tested against a bacteriophage bank, [...] Read more.

Increased antimicrobial resistance highlights the need for alternatives to antibiotics. Bacteriophages, which are benign viruses that kill bacteria, are promising. We studied the efficacy of topical bacteriophages for treating equine staphylococcal superficial pyodermas. Eight Staphylococcus aureus isolates were tested against a bacteriophage bank, and a cocktail consisting of two bacteriophages was prepared. Twenty horses with clinical and cytological evidence of superficial pyoderma and confirmed S. aureus infection based on swabbed culture were enrolled in the study. Each horse received both the bacteriophage cocktail and the placebo at two different infection sites, once daily for four weeks. Clinical lesions and cytology were evaluated weekly by an investigator who was unaware of the treatment sites. All infection sites were swabbed and cultured at the end of the study. A linear mixed model showed no significant differences between the placebo and treatment sites in terms of clinical signs, cytological scores of inflammation, and bacterial counts at the end of the study. It is possible that the bacteriophage cocktail killed S. aureus, but cytology scores did not change as new populations of cocci took over. The study limitations included a small sample size and inconsistent control of the underlying causes of pyodermas. Full article

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11 pages, 2080 KiB

Open AccessArticle

Low Prevalence of Toxoplasma gondii in Sheep and Isolation of a Viable Strain from Edible Mutton from Central China

by Yibao Jiang, Shilin Xin, Yiheng Ma, Heng Zhang, Xu Yang and Yurong Yang

Pathogens 2023, 12(6), 827; https://doi.org/10.3390/pathogens12060827 - 14 Jun 2023

Cited by 2 | Viewed by 1609

Abstract

Sheep are highly susceptible to Toxoplasma gondii, and miscarriage is the main clinical feature. This study investigated 227 sheep samples (210 myocardial tissues from slaughterhouses, 6 ewe serum samples, 3 aborted fetuses, and 8 dead lambs from veterinary clinics) from central China [...] Read more.

Sheep are highly susceptible to Toxoplasma gondii, and miscarriage is the main clinical feature. This study investigated 227 sheep samples (210 myocardial tissues from slaughterhouses, 6 ewe serum samples, 3 aborted fetuses, and 8 dead lambs from veterinary clinics) from central China for T. gondii infection. Antibodies against T. gondii were detected using the modified agglutination test (MAT). PCR was performed to detect T. gondii DNA in the tissue samples. The results showed that four samples were seropositive (MAT titer ≥ 1:100), with a seroprevalence of 1.8% (4/227). The seropositive samples included two myocardial samples from a slaughterhouse, one ewe and its aborted fetus from a veterinary clinic. The results revealed that 7 out of 207 (3.4%) sheep tissue samples were PCR-positive, including two myocardial tissue samples from slaughterhouses, three aborted fetuses, and two lambs from veterinary clinics. Toxoplasma gondii vertical transmission had occurred in two of three pairs of ewes and her pups. One viable T. gondii strain (TgSheepCHn14) was isolated from the myocardial tissues of sheep from a slaughterhouse. Tachyzoites were obtained from cell cultures at 70 days following seeding in the brains and lungs of mice. This strain was non-lethal to Swiss mice. The number of parasite brain cysts in mice decreased with time post-infection (p < 0.05). Overall, the prevalence of T. gondii in the sheep samples was low. Although the samples were scattered, and not from planned collections, the current study detected T. gondii antibodies and DNA in aborted fetuses, indicating that vertical transmission could occur and maintain the parasites in sheep herds without exogenous infection. Full article

(This article belongs to the Special Issue Toxoplasma Infection: Current Problems, Progress and New Challenges)

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Map showing the location of samples received from the Henan and Shandong provinces in China. I: Sanmenxia; II: Jiaozuo; III: Zhoukou; IV: Xinxiang; V: Pingdingshan; VI: Luoyang; VII: Xuchang; VIII: Shangqiu; IX: Zhumadian; X: Heze. Green represents sheep samples from the areas that tested positive for Toxoplasma gondii. Full article ">Figure 2
Morphology of Toxoplasma gondii TgSheepCHn14. (A) T. gondii cysts (arrow) were detected in Swiss mouse brain (Tox35-13, M#514), 16 days post-inoculation (DPI), squashed section, unstained, bar = 50 μm; (B) T. gondii tachyzoites (arrow) were found in the lungs of IFN-γ−/− mouse (Tox35-23, M#476ko), 16 DPI, smear, unstained, bar = 50 μm; (C) A cluster of T. gondii parasites (arrow) was found in the liver of IFN-γ−/−mouse (Tox35-23, M#476ko), 16 DPI, IHC, bar = 50 μm. (E,F) T. gondii parasites (square) were detected in Swiss mouse brain (Tox35-13, M#771), 26 DPI, H&E and IHC, continuous paraffin sections, bar = 50 μm. (D,G) Tachyzoites from cell culture, the conoid (Co), nucleus (Nu), rhoptries (Rh), micronemes (Mn), dense granules (Dg), apicoplast (A), mitochondrion (Mi), parasitophorous vacuolar membrane (Pm), parasitophorous vacuolar (Pv), tubulovesicular membrane network (Tn), and host cell mitochondrion HnMi were visible, TEM, bar = 1 μm. Full article ">Figure 3
Relationship between the number of Toxoplasma gondii brain cysts and survival time in mice (Mean ± SEM). Full article ">

10 pages, 279 KiB

Open AccessArticle

Rodents as Sentinels for Toxoplasma gondii in Rural Ecosystems in Slovakia—Seroprevalence Study

by Daniela Antolová, Michal Stanko, Júlia Jarošová and Dana Miklisová

Pathogens 2023, 12(6), 826; https://doi.org/10.3390/pathogens12060826 - 12 Jun 2023

Viewed by 1544

Abstract

Toxoplasma gondii is a ubiquitous intracellular parasite with felids as definitive hosts and a broad range of intermediate hosts. Rodents are considered suitable sentinels for prevalence studies of many infections, including toxoplasmosis. This study aimed to estimate the seroprevalence of T. gondii in [...] Read more.

Toxoplasma gondii is a ubiquitous intracellular parasite with felids as definitive hosts and a broad range of intermediate hosts. Rodents are considered suitable sentinels for prevalence studies of many infections, including toxoplasmosis. This study aimed to estimate the seroprevalence of T. gondii in rodents from different localities of Slovakia and investigate the correlation between the seropositivity and the species, age, sex, and sexual activity of animals. Altogether, 1009 wild rodents belonging to 9 species were trapped in 2015 and 2019, and antibodies to T. gondii were detected in 6.7% of the animals. Seropositivity was detected in seven species, ranging from 0.0% in Micromys minutus and Apodemus sylvaticus to 7.7% in A. flavicollis. The females reached significantly higher seropositivity (9.7%) than the males (3.8%), and the adults were positive significantly more often (9.2%) than the subadults (4.9%). The seropositivity differed also among localities, with significantly higher positivity detected in suburban and touristic areas (12.2%) than in localities with a lower level of human activities (5.5%). This study showed that the occurrence of T. gondii varies significantly in rodent species and habitats with various environmental conditions and different levels of anthropic use. Several biological and ecological factors, e.g., soil contamination, soil conditions, the susceptibility of rodent species etc., may influence this variability. Full article

(This article belongs to the Special Issue Toxoplasma gondii in Animals)

19 pages, 1722 KiB

Open AccessEditor’s ChoiceReview

Xylem Embolism and Pathogens: Can the Vessel Anatomy of Woody Plants Contribute to X. fastidiosa Resistance?

by Giambattista Carluccio, Davide Greco, Erika Sabella, Marzia Vergine, Luigi De Bellis and Andrea Luvisi

Pathogens 2023, 12(6), 825; https://doi.org/10.3390/pathogens12060825 - 12 Jun 2023

Cited by 6 | Viewed by 3707

Abstract

The maintenance of an intact water column in the xylem lumen several meters above the ground is essential for woody plant viability. In fact, abiotic and biotic factors can lead to the formation of emboli in the xylem, interrupting sap flow and causing [...] Read more.

The maintenance of an intact water column in the xylem lumen several meters above the ground is essential for woody plant viability. In fact, abiotic and biotic factors can lead to the formation of emboli in the xylem, interrupting sap flow and causing consequences on the health status of the plant. Anyway, the tendency of plants to develop emboli depends on the intrinsic features of the xylem, while the cyto-histological structure of the xylem plays a role in resistance to vascular pathogens, as in the case of the pathogenic bacterium Xylella fastidiosa. Analysis of the scientific literature suggests that on grapevine and olive, some xylem features can determine plant tolerance to vascular pathogens. However, the same trend was not reported in citrus, indicating that X. fastidiosa interactions with host plants differ by species. Unfortunately, studies in this area are still limited, with few explaining inter-cultivar insights. Thus, in a global context seriously threatened by X. fastidiosa, a deeper understanding of the relationship between the physical and mechanical characteristics of the xylem and resistance to stresses can be useful for selecting cultivars that may be more resistant to environmental changes, such as drought and vascular pathogens, as a way to preserve agricultural productions and ecosystems. Full article

(This article belongs to the Special Issue Pathogens in 2023)

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Factors that determine resistance to cavitation, which are many and often differ according to the plant species and the context in which they are observed. However, it can be assumed that plants characterized by short xylem vessels, with a small diameter and with small and few pits, are more resistant to cavitation. Full article ">Figure 2
Schematization of the pathogen spread (represented in brown color) in the xylem tissue of susceptible or resistant plants: (A) xylem of the Phaeomoniella chlamydospora–susceptible grapevine cultivar Thompson Seedless, characterized by wide and long xylem vessels (photo from [<a href="#B100-pathogens-12-00825" class="html-bibr">100</a>], bar = 1 mm); (B) xylem of the Ophiostoma ulmi–tolerant elm hybrid Dodoens, capable of a fast reaction to infection that includes the formation of much smaller vessels and an increase of their density (photo from [<a href="#B101-pathogens-12-00825" class="html-bibr">101</a>], bar = 500 μm); (C) comparison of the xylem between the Raffaelea lauricola–susceptible avocado cultivar Simmonds (I and II) and the resistant one Duke (III and IV), in which besides differences in vessel length and diameter (C I and C III), any significant difference in the vessel’s density and organization is reported (photo from [<a href="#B102-pathogens-12-00825" class="html-bibr">102</a>], bar = 1500 μm); (D) vessel ending (red) at the petiole level, which acts like filter for emboli and pathogens, especially at the junction between leaf and stem; adjacent long and open vessels (blue) can facilitate the circulation of emboli or pathogens. Full article ">Figure 3
The cavitation process in xylem vessels infected by X. fastidiosa: (1) X. fastidiosa can move actively between vessels by hydrolyzing pit membranes; (2) this can lead to the production of emboli, which seem to stimulate the defensive response of the plant that starts to produce gums and tyloses, as well as those induced by the pathogen; (3) in the most advanced infection stages, gums, tyloses, and bacterial colonies can occlude the vessels, causing cavitation, which favors the survival of the pathogen. Full article ">

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