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Biomedical subjects

A F Pinigin

Publications and source records attributed to A F Pinigin.

At least 19 recordsLinked to original sources

[Dynamics of drug resistance of Vibrio cholerae isolated from surface water reservoirs in Siberia and the Soviet Far East in 1976-1990].

In the study on antibiotic resistance 1383 strains of El Tor Vibrio cholerae isolated from surface water reservoirs in 12 administrative territories of the Siberia and Far East within a period of 15 years were tested. The following antibiotics were used: ampicillin, streptomycin, monomycin, polymyxin, tetracycline, chloramphenicol, rifampicin and nalidixic acid. The resistance was unstable and its pattern was wave-like according to annual changes in the biological cycle. It was especially evident in regard to ampicillin, streptomycin, monomycin and polymyxin. The highest numbers of the strains were resistant to polymyxin, ampicillin and streptomycin (up to 100 per cent in some years). The lowest numbers of the strains were resistant to chloramphenicol (0.4 per cent) and tetracycline (1.9 per cent). No strains resistant to rifampicin and nalidixic acid were isolated. In some cases the antibiotic resistance level depended on the geographical zone where the strain was isolated. A direct quantitative dependence of the resistance level on the MIC was observed: the lower the MIC of the drug was, the lower the number of the strains resistant to it was. Within the 15-year period there was no general tendency to increase the resistance in V. cholerae to the antibiotics used.

Drug Resistance, Microbial↗

[Lecithinase activity of Vibrio cholerae and of vibrios not agglutinated by O-cholera serum].

The lecithinase activities of 187 V. cholerae strains differing in their virulence and 70 cultures of NAG vibrios of different origin varied in all experimental groups. The level of lecithinase activity in the groups of V. cholerae strains having low virulence, or no virulence at all, was considerably higher than in virulent strains. NAG vibrios isolated from diarrhea patients and from samples of lake and pond water did not differ in the activity of this enzyme.

Humans↗

[Comparative antibiotic sensitivity of NAG vibrios].

Six hundred and forty eight NAG vibrio strains isolated at various periods from patients and carriers and from environmental objects such as surface of water reservoirs and sewage were studied with respect to their sensitivity to 14 antibiotics with the method of serial dilutions in solid media. Irrespective of the isolation place, object and time, the NAG vibrios were highly resistant to penicillins and polymyxin M. At the same time they were highly sensitive to gentamicin (MIC 1-2 micrograms/ml), levomycetin (MIC 0.5-1 micrograms/ml) and tetracyclines (MIC 0.25-1 micrograms/ml). Study of the recipient capacity of NAG vibrios with respect to R plasmids showed that they could be recipients of exogenic R plasmids of various incompatibility groups.

Anti-Bacterial Agents↗

[Phage typing of nonagglutinating vibrios isolated in the territory of the USSR].

The work presents the results of the phage typing of 2,437 NAG vibrio strains isolated in the USSR from patients and carriers (374 strains), from open water basins (1,675 strains), from sewage (234 strains) and from bottom silt (172 strains). Phage typing was carried out with a set of 5 phages capable of lyzing enteropathogenic NAG vibrios (phages TEPV 1, 2, 3, 4, 5). NAG vibrios isolated from humans were sensitive to phages TEPV in 45% of cases and NAG vibrios isolated from the environment, only in 29.9% of cases. Enteropathogenic NAG vibrios belonging to phagovar 1 were isolated most frequently from samples taken both from humans and from the environment. The NAG vibrios isolated from patients, carriers and the sources of water supply nearest to them belonged to the same phagovars.

Animals↗

[Br. ovis sensitivity to antibiotics].

Irrespective of their geographical origin the cultures of Br. ovis are highly sensitive to tetracycline and streptomycin. The bactericidal concentrations of tetracycline for 86.6 per cent of the strains and streptomycin for 93.20 per cent of the strains were 0.02--0.04 and 0.1--0.4 gamma/ml respectively. The bactericidal effect of morphocycline, kanamycin, benzyl-penicillin, lincomycin and monomycin was less pronounced. Polymyxin M had no bactericidal effect on the Brucella even in concentrations of 200 gamma/ml. Antibiotic sensitivity of S-subcultures of Br. ovis and the initial R-variants was studied comparatively. It was found that genetically related S-subcultures of Br. ovis were more resistant to the antibiotics than the initial R-strains.

Anti-Bacterial Agents↗

[The interrelationships between Vibrio cholerae and the infusorian Tetrahymena pyriformis].

The results of the study of interaction between V. cholerae of different virulence and T. pyriformis are presented. The study has revealed the heterogeneity of V. cholerae population: alongside easily phagocytized vibrios, there are vibrios resistant to the digestive action of T. pyriformis. An increase in the number of V. cholerae in association with T. pyriformis has been evaluated, taking into account the selective multiplication of vibrios resistant to phagocytosis. The data on changes in the agglutinative, phagolytic and virulent properties of V. cholerae cultivated together with T. pyriformis are presented. The suggestion has been made that protozoa can function as hosts of pathogenic vibrios supporting their existence in water.

Animals↗

[The characteristic properties of Vibrio cholerae eltor isolated from environmental objects on the territory of the former USSR during the 7th cholera pandemic].

The properties of 22,382 V. eltor strains isolated from environmental objects on the territory of different climatic and geographical zones during the period of 1970-1988 were studied. The study was made on the morphology of their colonies, the agglutinability of the strains by cholera O serum, type-specific serum and RO serum, their capacity for being lyzed by V. eltor bacteriophage, their hemolytic activity and virulence. Differences in the occurrence of strains with any of the above-mentioned properties, depending on the object from which they were isolate, the climatic and geographical zone and the intensity of the epidemiological situation with regard to cholera.

Cholera↗