Search Results (7)

Toxoplasma gondii is a ubiquitous zoonotic parasite with a wide range of warm-blooded animals as intermediate hosts, where the transmission primarily occurs through ingesting T. gondii oocysts in the environment. Hence, animals inhabiting a wide geographical range can be sentinels for the environmental contamination of T. gondii oocysts. The aim of this study was to determine the seroprevalence of T. gondii in two generalist ungulates in the Republic of Korea (ROK), wild boar (Sus scrofa) and Korean water deer (Hydropotes inermis argyropus), and identify the risk factors associated with this infection. Commercial ELISA kits confirmed a seroprevalence of 34.9% in wild boar (170/487, 95% CI: 30.7–39.3%) and 29.9% in Korean water deer (135/452, 95% CI: 25.7–34.3%). In both species, the seroprevalence was highest in winter, and showed no sex-related differences. In wild boars, the seroprevalence showed steep reduction in 2020 and increased with body mass. Meanwhile, in Korean water deer, seroprevalence did not show significant association with any of the tested variables, although an increase in seroprevalence was observed in 2020 compared to previous years. This study documents the widespread yet heterogeneous nature of T. gondii prevalence in its intermediate host population. Hence, the constant monitoring of T. gondii prevalence in its host species, both definitive and intermediate, while simultaneously considering risk factors would be necessary to identify the drivers behind the fluctuating pattern of T. gondii prevalence. Full article

Tick-borne diseases result from human–ixodid tick encounters, making it crucial to understand host–ixodid tick interactions and host-dependent distribution for epidemiology and prevention. This study examines water deer patterns and ixodid tick interactions in designated croplands of South Korea over two years, finding that the highest deer presence occurred in July and the lowest in May, during crop harvesting. Four tick species were identified, with Haemaphysalis longicornis being predominant (92.2%). Tick life stage analysis revealed peak nymphs and adults in July and larvae in October. Nymph abundance correlated positively with nearby water deer. MaxEnt biodiversity prediction results indicated wider water deer distribution in summer, reflecting their tendency to use multiple croplands. Areas with nymphs and adults aligned with predicted deer presence in summer, while larval areas aligned in autumn. Increased agroforestry expanded water deer habitats, enhancing tick dispersion. Prevention involved minimizing human–deer encounters by strategic land use in tick-prone areas. This comprehensive study provides insights into preventing severe fever with thrombocytopenia syndrome in agricultural workers, emphasizing the need for targeted interventions based on host behavior and tick life stages in different seasons. Full article

The Korean water deer (WD), a predominant wildlife species in South Korea, is listed as vulnerable by the IUCN Red List. Despite belonging to the same family, Cervidae, WD show significantly fewer adult ixodid tick infestations compared to roe deer (RD). Ticks, which cannot fly, engage in questing behavior in natural environments to latch onto hosts. They detect signals like body temperature and host skin chemicals to navigate through the hair coat to the preferred epidermis. In light of this, we performed an extensive comparative study of the skin tissue and hair characteristics of both deer species, focusing on elements contributing to the reduced tick bite incidence in WD. Remarkably, WD exhibited more prominent blood vessels, sebaceous glands, and sweat glands, which are crucial for skin barrier functions (p < 0.005). Moreover, WD had irregular scale patterns on their hair cuticles and possessed hair that was significantly stiffer and 2.83 times thicker than that of RD (p < 0.001). These characteristics potentially impede ticks from reaching the epidermis hair in WD and RD in the context of tick bite prevention. Further investigations in this area could enhance our understanding of tick–host dynamics and contribute to developing preventive measures against tick-borne diseases in other deer species. Full article

Ambiguous, heterogeneous, endospore-forming Bacillus species, notably Bacillus cereus, often produce fatal toxins that threaten human health. We identified Bacillus from wild animal fecal samples (n = 80), including the Korean water deer (n = 25) and striped field mouse (n = 55). Using traditional culture-based methods, 25 animal fecal samples (31.25%; 25/80) were found to be positive for Bacillus species, whereas using molecular techniques, 19 samples (23.75%; 19/80) were found to be positive for the same. In addition, we designed a Bacillus species-specific 16S ribosomal RNA (rRNA) gene marker and utilized it to identify 19 samples by means of PCR amplification and sequencing, using at least one colony from the 19 Bacillus positive samples. The recovered sequences were matched to sequences of three Bacillus species (B. cereus, B. amyloliquefaciens, and B. megaterium) from the GenBank database. Moreover, the phylogenetic tree generated in this study established specific clades for the Bacillus group. In addition, to differentiate between B. cereus, B. anthracis, and B. thuringiensis, we designed a single nucleotide polymorphism (SNP)-based primer by identifying SNPs in the alignment of 16S rRNA gene sequences of B. cereus group strains. The SNPs were used to design primer sets for discrimination between highly similar species from the B. cereus group. The study could be used in surveillance of agricultural fresh-produce-associated Bacillus outbreaks, for accurate identification of each Bacillus species, and in the development of control measures. Full article

In recent decades, rapid industrial growth has accelerated the construction of new roads, which has led to the destruction and isolation of wildlife habitats. Newly constructed roads affect wildlife in many ways. In particular, fatal wildlife-vehicle collisions (WVCs) have a direct impact on wildlife. A substantial number of WVCs occur every year on expressways, where vehicle speeds and vehicle traffic are significant. However, our understanding of the relative importance of the factors associated with areas in which large numbers of WVCs occur on the expressway remains poor. Therefore, herein, we analyze the spatial characteristics of WVCs. The effect of spatial distribution on the occurrence of WVCs was analyzed using the types of land cover in the areas where water deer appear (Cheongju, Boeun, and Sangju) and the areas in which WVCs occur along the Cheongju–Sangju Expressway (CSE). We identified the WVC hotspots by using CSE patrol data recorded between January 2008 and December 2019, and we analyzed the corresponding distribution patterns and land cover characteristics. Along the CSE, a total of 1082 WVCs occurred, out of which collisions involving water deer (Hydropotes inermis argyropus) accounted for 91%. Water deer appear frequently in Forested Areas and Agricultural Land, but the WVC distribution in the Hotspots followed a highly clustered pattern, with a higher proportion of WVCs occurring in Used Areas (areas including buildings such as residential facilities, commercial and industrial facilities, and transportation facilities). Used Areas have a smaller cut slope compared to Forested Areas, and Used Areas are open terrains. Therefore, the occurrence of WVCs will be high given that wildlife can easily access the expressway. Based on these results, we can infer that the landscapes near the expressway influence the occurrence of WVCs. To establish an effective policy for reducing WVCs on a road, the WVC characteristics and spatial distribution of the road should be considered together. Further research on the wildlife ecology and land-use status of WVC hotspots is required to mitigate WVCs on expressways and protect human and animal life. Therefore, if the characteristics of WVC hotspots are analyzed considering the characteristics of various ecosystems, an appropriate WVC reduction plan can be established. Full article

Fences have been widely implemented to reduce the risk of wildlife–vehicle collisions, wildlife disease spread, and crop damage. To manufacture fences, it is imperative to assess the behavioural responses of the target species. Here, we investigated the success rate of fences and classified eight behavioural responses of Korean water deer (Hydropotes inermis argyropus) to different fence heights. We explored the association of 801 behavioural responses and defined a threshold based on 40 events by applying non-metric multidimensional scaling and a binary logistic generalised linear mixed model. With fences lower and higher than 1.2 m, recession and rest were the dominant behaviours, respectively, before the deer crossed the fences by performing vertical and running jumps. Considering all independent events, 0.9 m was the marginal threshold, with highly variable outliers over this value. Placing exit pathways for deer and eliminating possible resting areas outside fences are essential for reducing the number of successful jump attempts. The optimal fence height could differ based on conditional factors; however, we recommend a height of 1.5 m considering the cost and roadkill risk. In conclusion, exploring and classifying the behavioural responses of the target species may be critical for establishing appropriate fence protocols. Full article

Blastocystis is a protozoan parasite commonly detected in the intestinal tract of humans and animals. It has been actively studied worldwide; however, information on Blastocystis is limited in Korea. Because there is an increasing concern about the contact between wildlife and domestic animals or humans, we assessed the infection status and zoonotic potential of Blastocystis in Korean water deer (KWD, Hydropotes inermis argyropus) using genotyping and phylogenetic analysis. A total of 125 fresh fecal samples were collected from KWD which were killed by vehicles on highways or roadsides in this study. Among the 125 samples, 51 (40.8%) were PCR positive. We performed nucleotide sequencing and phylogenetic analysis of 26 of the 51 PCR-positive samples. By analyzing Blastocystis 18S rRNA, two subtypes (ST4 and ST14) were identified in this study. Of the 26 samples analyzed, 25 were identified as ST14 and one as ST4. Infection of ST14 in humans has not been reported. Although only one ST4 sample was detected in this study, ST4 has zoonotic potential without showing ruminant specificity. Thus, continuous attention should be provided to the potential of transmission between wildlife and domestic animals and humans. Full article