SU1565892A1 - Method of determining sensitivity of gonococcus to antibiotic - Google Patents

Abstract

This invention relates to medicine and may be used in the treatment of gonorrhea. The purpose of the invention is the acceleration of the method. Gonococcus culture is isolated from the patient with gonorrhea and sown on a dense medium. In parallel, blood samples were taken 1 h after the administration of the antibiotic, the serum was separated and a series of dilutions were prepared using plasmol. The prepared serum dilutions are added to the gonococcus cultures and incubated for 5-6 hours. After the incubation, the cultures are microscopically examined and in the absence of culture growth with a certain serum dilution containing the appropriate amount of antibiotic, the minimum inhibitory concentration of the antibiotic is determined and, accordingly, the bactericidal activity of the blood serum . From the results obtained, it is concluded that the antibiotic used for the treatment is effective.

Description

This invention relates to medicine and may be used in the treatment of gonorrhea.

The purpose of the invention is the acceleration of the method.

The method is carried out as follows.

The material under study is plated on microsepton or blood agar. The obtained pure culture is suspended in a physiological solution to a concentration of 10 units. optical turbidity standard.

A thin capillary of a Pasteur pipette is seeded with a suspension of autoculture (0.15 0.25 mm) into square blocks of a dense nutrient medium,

placed on a sterile glass slide. The blocks are made of plastagara. After seeding the microorganisms, the blocks are covered with a cover glass.

In parallel, blood samples are taken from patients 60 minutes after intramuscular or oral administration of one type of antibiotic.

In the chambers prepared using the method described above, a Pasteur pipette with a thin capillary was injected using serial dilution with a patient's serum containing an antibiotic and plasmol. The dilution of the blood serum in the first chamber of the row is 1: 2 (0.5 ml of plasmol + 0.5 ml of the patient's serum). Scatter number

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it determines the pharmacokinetic features of the antibiotic: 8,16,32 and so on (for aminoglycosides, the maximum serum dilution is 1: 128). The control chambers contain a nutrient medium, which contains human serum and the biogenic stimulator plasmol in equal volume ratios. Chambers in Petri dishes are placed in a thermostat and cultured at 37 ° C. After 5-6 hours, the chambers are removed from the thermostat and, due to their transparency, the growth of gonococci is determined in a phase-contrast microscope. In the control chamber, gonococcal microcolonies grow during this time. In the experimental growth chambers, the pathogens will not be if the appropriate antibacterial serum dilutions in the patient's serum dilutions contain the amount of the antibacterial drug. The highest dilution of patient serum causing growth retardation is the antibacterial serum test (ATC).

When determining the serum antibacterial activity (AAS) in patients, it was established that titer values range from 1: 2 to 1: 128. As a result of determining sensitivity to prescribed antibiotics, it turned out that the highest serum titer values (1:32 - 1: 512) correspond to sensitive strains. When isolating pathogen strains that are insensitive to the antibiotic administered, the titer is 1: lf - 1:16. In the case of isolation, resistant AAS strains are low (1: 2) or not detected at all.

The conducted studies show the coincidence of AAS indicators with the clinical efficacy of antibiotic therapy. With AAS, the estimated titer value of 1: 2, the dynamics of the infection course with the start of penicillin therapy was not detected in any of the 16 patients with various clinical forms of gonorrheal infection (fresh acute, fresh subacute, fresh torpid and chronic gonorrhea urethritis). Without continuing further treatment with penicillin, since it would be ineffective, penicillin was replaced by other patients for this patient.

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biotics - aminoglycosides with a broad antibacterial spectrum of action (kanamycin, monomitsin, gentamicin), to which a high sensitivity of the isolated gonococcal autostrains is noted.

Example 1. Patient T., 32 years old, entered the dermatovenerologic department of the hospital with a diagnosis of fresh torpid gonorrheal urethritis. When the patient was admitted to the hospital, seeding of the urethra was carried out on conventional nutrient media, mnepton agar and blood agar, in order to isolate the gonococcal autostrain. After 1 day after clinical and topical examinations, the patient was prescribed treatment according to the generally accepted treatment regimen. Penicillin was prescribed as an antibiotic. After 1 hour after the first injection of penicillin (a shock dose of 600 thousand U), the patient is bled from the cubital vein and centrifuged. An antibiotic serum and preliminarily prepared plasmol are introduced into the plastic chambers coated with slides in a Pasteur pipette into which cells are pre-seeded and suspended in physiological saline to a concentration of 10 U according to the optical turbidity standard of an auto-strain of a gonococcal culture of a patient. The dilution of blood serum in the first chamber of a row is 1: 2 (0.5 ml of patient serum and 0.5 ml of plasmol). The number of serum dilutions is 1: 2 to 1: 128. Control chambers contain gonococcus auto-strain4 and nutrient medium from human serum (without antibiotics) and plasmol biostimulant in equal volume ratios (1: 1). All microcameras in Petri dishes are placed in a thermostat and cultured at 37 ° C. After 6 hours, the chambers are removed from the thermostat and examined under a microscope for the presence of gonococcal microcolony growth in all dilutions of the p and the control. Bacterioscopy revealed the growth of microcolonies of the gonococcus autotum strain in the control, as well as in all dilutions of the serum with antibiotic penicillin from 1: 128 to 1: 2 inclusive. The results obtained are the basis for stopping further treatment of this patient with penicillin. The antibiotic kanamycin, the sensitivity to which gonococcus is very high (at a maximum dilution of 1: 6k), is assigned to the freestyle. The result is a complete clinical and etiological cure for the patient.

Example 2. Patient V., 2k years old, entered the dermatovenerologic department of the hospital with a diagnosis of chronic gonorrheal urethritis. From the anamnesis, it was established that the duration of the disease was 5 carried. Previously, the patient was undergoing antibiotic treatment. After a course of treatment, gonococci were detected in the control bacposse. Thus, prior treatment was ineffective, which caused the recurrence of infection. Upon admission of the patient to the hospital, bacteriological seeding from the urethra to the nutrient medium was carried out and after 2k hours colonies of the auto-strain of the pathogen were found in the seeding. The patient is prescribed treatment according to the generally accepted scheme. After 1 h after the first injection of penicillin, the patient takes blood from a vein and centrifuged. Plasmol is added to the antibiotic serum, after which the mixture is inserted with a Pasteur pipette into plastagar’s chambers covered with slides. 8 chambers are pre-seeded suspended in a physiological solution to a concentration of 10 U according to the optical standard of turbidity of the autoshtems of the daily culture of gonococcus isolated from the patient. The number of serum dilutions in the range from 1: 2 to 1: 128. Experimental and control microcameras in Petri dishes are cultivated at

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thermostat and conduct bacterioscopic research on the presence of growth of gonococcus microcolonies. Research results show the presence of growth of gonococcal microcolonies in the control and breeding of a number, starting with and above. The results of the research were the basis for the abolition of antibiotic therapy of penicillis in the thermostat.

370C. After 5 hours, the cameras are removed.

This patient has to be replaced with an antibiotic, gentamicin, to which this auto-strain of gonococcus was quite high. The treatment with kanamycin made it possible to achieve a complete clinical and etiological cure for the patient.

Q The method can be used to determine the sensitivity to antibiotics of various microorganisms both in the course of treatment and v to determine the minimum inhibitory concentration of the antibiotic by the double-dilution method in an appropriate nutrient medium.

The use of the method allows to speed up the selection of an effective antibiotic based on the individual characteristics of the patient. In addition, the method is highly informative, as it allows observing the culture of the infectious agent in a microscope. 5 Determining the sensitivity of micropopulations of gonorrhea pathogens to antibiotics makes it possible to assess their heterogeneity by this property, to determine the number of individuals tolerant to anti-tibiotics, to characterize the change in the morphological and some other properties of the microorganisms under study.

Claims (1)

Invention Formula The method of determining the sensitivity of gonococci to an antibiotic in the process of antibiotic treatment of a patient with gonorrhea infection by isolating the autoculture of gonococci, incubating the latter on solid nutrient medium in the presence of an antibiotic, and determining the sensitivity of gonococci to the antibiotic by the presence or absence of growth, which, in order to accelerate the method, incubation is carried out for 5 to 6 hours in the presence of a patient’s serum containing an antibiotic used for treatment, diluted with plasmolo m