title: Demonstration of R factors in Bordetella bronchiseptica isolated from pigs.
abstract: Transferability of drug resistance in strains of Bordetella bronchiseptica isolated from pigs was examined. These strains were resistant to sulfadimethoxine (SA, more than 1,600 mug/ml), streptomycin (SM, more than 800 mug/ml), and aminobenzyl penicillin (APC, 200 mug/ml). All of them could transfer their drug resistance as one unit to a sensitive strain of Escherichia coli as well as to B. bronchiseptica by mixed cultivation. The transferred SM-SA-APC resistance in the exconjugants of E. coli and B. bronchiseptica was also transmissible by mixed cultivation. But the transfer of triple resistance was not mediated by the cell-free filtrate of the drug-resistant strain of B. bronchiseptica which was used as donor. The triple resistance in the exconjugant E. coli ML1410 was found to be eliminated as a whole by treatment with acriflavin. According to these results, it could be safely concluded that R factors carrying SM-SA-APC resistance were demonstrated in strains of B. bronchiseptica isolated from pigs.
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001884:Bordetella / Q000187:drug effects*; D004352:Drug Resistance, Microbial; D005111:Extrachromosomal Inheritance; D008826:Microbial Sensitivity Tests; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents