Comparative study of Vibrio cholerae non-O1 isolated from 2 rivers according to antibiotics and metals susceptibility.
Vibrio cholerae non-O1 was isolated at six locations on each of two different rivers in 1984 and 1985. A study of the strains isolated from these rivers according to antibiotic and metal susceptibility and the incidence of resistant strains produced the following results. 1) Tests to determine susceptibility to eight antibiotics (chloramphenicol, tetracycline, streptomycin, kanamycin, ampicillin, gentamicin, nalidixic acid and polymyxin-B) indicated that there was virtually no difference in the susceptibility of strains isolated from the two rivers. Of the 115 environmental strains, 81 (70.4%) showed resistance to one or more drugs. However, no strains were resistant to gentamicin. There was considerable variation in the concentration of susceptibility to polymyxin-B, and for this reason it was difficult to determine the resistance concentration. 2) 64.3% (74/115) of the strains isolated from the two rivers showed ampicillin resistance and produced beta-lactamase. 3) 67.9% (55/81) of all resistant strains were resistant only to ampicillin, while 16.0% (13/81) were resistant to ampicillin and nalidixic acid. The rate of resistance to these substances was higher than to the other drugs. 4) The incidence of resistant strains differed according to environmental conditions along the two rivers. These variations appear to reflect the influence of environmental conditions in the catchment areas. 5) There was no metallic contamination in either the Sagami River, which has good water quality, or the Sakai River, which is heavily polluted. This meant that there was no variation in the metal susceptibility of the isolated strains according to differences in the degree of water pollution. Furthermore, none of the strains showed resistance to metals.
Uchiyama
H
H
Department of Public Health, School of Hygienic Sciences, Kitasato University.
Todoroki
T
T
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D005618:Fresh Water; D007564:Japan; D008670:Metals / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D014734:Vibrio cholerae / Q000187:drug effects* / Q000302:isolation & purification; D014871:Water Microbiology
D000900:Anti-Bacterial Agents; D008670:Metals