title: Drug resistance of enteric bacteria. 13. Distribution of R factors in Escherichia coli strains isolated from livestock.
abstract: Escherichia coli strains isolated from 151 swine and 108 fowl, which were kept at the Animal Health Center, Maebashi, Japan, were surveyed for drug resistance and distribution of R factors. All of the swine and 38% of the fowl excreted E. coli strains resistant to tetracycline, chloramphenicol, streptomycin, and sulfanilamide, or certain combinations thereof. Among 278 resistant cultures isolated from swine, 13% were found to be resistant to one antibiotic, whereas 87% were resistant to more than one antibiotic. Among these resistant strains, 40% carried R factors which were transferable by the usual conjugal process. The resistance patterns of these R factors included 36% which were singly resistant and 64% which were multiply resistant. Among 54 resistant cultures isolated from fowl, 24% were singly resistant and 76% were multiply resistant. Of the resistant strains from fowl, 22% carried R factors. The resistance patterns of R factors included 50% of the singly resistant type and 50% which were multiply resistant. In spite of feeding with dairy products containing only tetracycline, a high incidence of multiple resistance was observed in the E. coli strains and the R factors isolated from these animals.
mesh_terms: D000818:Animals; D002701:Chloramphenicol / Q000494:pharmacology*; D003227:Conjugation, Genetic; D004352:Drug Resistance, Microbial; D004926:Escherichia coli; D005111:Extrachromosomal Inheritance; D005827:Genetics, Microbial; D011200:Poultry; D013307:Streptomycin / Q000494:pharmacology*; D013424:Sulfanilamides / Q000494:pharmacology*; D013552:Swine; D013752:Tetracycline / Q000494:pharmacology*
chemical_list: D013424:Sulfanilamides; D002701:Chloramphenicol; D013752:Tetracycline; D013307:Streptomycin