A survey on drug resistance and R plasmids in Salmonella isolated from domestic animals in Japan.

Abstract

A total of 217 Salmonella strains isolated from domestic animals (78 strains from cattle, 74 from swine and 65 from chickens) in Japan in 1976 were examined for drug resistance and prevalence of R plasmids. S. typhimurium and S. enteritidis were commonly encountered among 20 serovars identified in this survey. Of the 217 strains examined, 164(76%) were resistant to one or more of the drugs tested. High incidence of multiple drug resistance was observed in the Salmonella strains of cattle origin, over 70% of which showed a multiple resistance to chloramphenicol, tetracycline, streptomycin and sulfonamide. Of the 164 resistant Salmonella strains, 104 (63%) were found to carry R plasmids which were capable of performing a conjugal transfer. Of them, 64 (62%) were originated from cattle. Most of them had multiple resistant markers, including chloramphenicol. It was also found that R plasmids of incompatibility groups H1 and Iα were widely distributed among Salmonella strains isolated from domestic animals, especially from cattle, in Japan.