[Antibiotic sensitivity of El Tor Vibrio cholerae after exposure to various pesticides and mineral fertilizers]. / Antibiotikochuvstvitel'nost' kholernykh vibrionov El'-Tor, podvergnutykh vozdeistviiu nekotorykh pestitsidov i mineral'nykh udobranii.

The strains of El Tor Vibrio cholerae were exposed to different concentrations of pesticides (fazolone, treflane, prometrine, magnesium chlorate, omait and gardon) and mineral fertilizers (superphosphate, ammophos and carbamide) for 2 to 135 days. The subcultures of various ages were tested for their sensitivity to 16 antibiotics. The whole of 229 cultures were tested. There was a general tendency to lowering of the El Tor vibrio sensitivity to the majority of the antibiotics tested. The vibrio strains resistant to the antibiotics widely used in medical practice i. e. levomycetin, streptomycin, tetracycline, lincomycin, neomycin and kanamycin were isolated.

[Comparative features of methos of inducing auxotrophic mutants of cholera and nonagglutinating vibrios]. / Sravnitel'naia kharakteristika metodov induktsii auksotrofnykh mutantov kholernykh i neaggliutiniruiushchikhsia vibrionov.

The effect of chemical mutagens (EI, NEU, NMU, NMG) on six El-Tor strains and eight NAG-vibryos was studied in order to obtain auxotrophic mutatns. The methods used showed the advantage of A. Adelberg and D. Mayers's method in the Yu. G. Suchkov's modification. It enables to get a greater number of mutants, and it differs from other methods in the simplicity in organization of experiments. The mutants obtained of El-Tor and NAC-vibryos differed from each other and from initial strains in their biochemical properties, agglutinability, phagolisability and culture requirements.