High-frequency transfer of a naturally occurring chromosomal tetracycline resistance element in the ruminal anaerobe Butyrivibrio fibrisolvens.

摘要: Butyrivibrio fibrisolvens strains resistant to tetracycline were isolated from the bovine rumen. Two of three Tcr B. tested able donate resistance at frequencies ranging 10(-7) 10(-1) per donor cell in anaerobic filter matings a rifampin-resistant mutant type strain B.fibrisolvens, 2221R. The recipient 2221R exhibited rapid autoaggregation, which might be factor high transfer rates observed. transconjugants also capable further transferring fusidic acid-resistant mutant, 2221F. Comparison genomic DNAs by pulsed-field gel electrophoresis demonstrated altered band profiles transconjugants, consistent with acquisition large mobile chromosomal element. transferable elements two donors 1.23 and 1.230 (TnB123 TnB1230, respectively) showed same preferred insertion site chromosome are likely similar, or identical, elements. Hybridization experiments no close relationship between TnB1230 int-xis regions Tn916 Tn5253. Although DNA hybridized probes carrying tet(M) tet(O) sequences, found have acquired distinct that only weakly these probes, suggesting second, distantly related determinant had been transferred.