Frequency of drug resistance in Vibrio spp. in Japan

Marine Vibrio spp. isolated from the intestinal tracts of yellowtails (Seriola quinqueradiata) cultured on the farm of the Kochi Prefecture and goby (Periophthalmus cantonensis) in the Ariake Sea, west Kyushu Island in Japan, were found to be resistant to aminobenzylpenicillin (Ap) as well as various heavy-metal ions. Ap-resistance was detected in about 78% of drug-resistance strains; all the strains tested were resistant to lead acetate, sodium arsenate, cobalt chloride, cadmium chloride and nickel sulphate, respectively. However, the level of drug resistance against mercury chloride was slightly different between strains isolated from two different areas and no transferable resistance plasmid was observed. Substrate profile analysis of Vibrio spp. SV-20 and SV-87 from yellowtails indicated that Ap-resistance was due to type IV penicillinase.