J. Bacteriol., 12 1996, 6671-6676, Vol 178, No. 23
Copyright © 1996, American Society for Microbiology

Conjugal transfer of the 5-nitroimidazole resistance plasmid pIP417 from Bacteroides vulgatus BV-17: characterization and nucleotide sequence analysis of the mobilization region

S Trinh, A Haggoud and G Reysset
Unite des Anaerobies, Institut Pasteur, Paris, France.

Three small 5-nitroimidazole (5-Ni) resistance plasmids (pIP417, pIP419, and pIP421) from Bacteroides clinical isolates are transferable by a conjugative process during homologous or heterologous matings. The mobilization properties of pIP417 originated from strain BV-17 of Bacteroides vulgatus were studied. The plasmid was successfully introduced by in vitro conjugation into different strains of Bacteroides and Prevotella species and could be transferred back from these various strains to a plasmid-free 5-Ni-sensitive Bacteroides fragilis strain, indicating that in vivo spread of the resistance gene may occur. The transfer of plasmid pIP417 harbored by the Tc(r) strain BF-2 of B. fragilis was stimulated by low concentrations of tetracycline or chlorotetracycline. This suggests a possible role for coresident conjugative transposons in the dissemination of 5-Ni resistance among gram-negative anaerobes. The nucleotide sequence of the 2.1-kb DNA mobilization region was determined. It contains a putative origin of transfer (oriT) in an A+T-rich-region, including three inverted repeats, and two integration host factor binding sites. The two identified mobilization genes (mobA and mobB) are organized in one operon and were both required for efficient transfer. Southern blotting indicated that the mobilization region of plasmid pIP417 is closely related to that of both the erythromycin resistance plasmid pBFTM1O and the 5-Ni resistance plasmid pIP419 but not to that of the 5- Ni resistance plasmid pIP421.

This article has been cited by other articles:

• Soki, J., Gal, M., Brazier, J. S., Rotimi, V. O., Urban, E., Nagy, E., Duerden, B. I. (2006). Molecular investigation of genetic elements contributing to metronidazole resistance in Bacteroides strains. J Antimicrob Chemother 57: 212-220 [Abstract] [Full Text]  
• Lofmark, S., Fang, H., Hedberg, M., Edlund, C. (2005). Inducible Metronidazole Resistance and nim Genes in Clinical Bacteroides fragilis Group Isolates. Antimicrob. Agents Chemother. 49: 1253-1256 [Abstract] [Full Text]  
• Sweeney, L. C., Dave, J., Chambers, P. A., Heritage, J. (2004). Antibiotic resistance in general dental practice--a cause for concern?. J Antimicrob Chemother 53: 567-576 [Abstract] [Full Text]  
• Vedantam, G., Hecht, D. W. (2002). Isolation and Characterization of BTF-37: Chromosomal DNA Captured from Bacteroides fragilis That Confers Self-Transferability and Expresses a Pilus-Like Structure in Bacteroides spp. and Escherichia coli. J. Bacteriol. 184: 728-738 [Abstract] [Full Text]  
• Jeong, J.-Y., Mukhopadhyay, A. K., Dailidiene, D., Wang, Y., Velapatiño, B., Gilman, R. H., Parkinson, A. J., Nair, G. B., Wong, B. C. Y., Lam, S. K., Mistry, R., Segal, I., Yuan, Y., Gao, H., Alarcon, T., Brea, M. L., Ito, Y., Kersulyte, D., Lee, H.-K., Gong, Y., Goodwin, A., Hoffman, P. S., Berg, D. E. (2000). Sequential Inactivation of rdxA (HP0954) and frxA (HP0642) Nitroreductase Genes Causes Moderate and High-Level Metronidazole Resistance in Helicobacter pylori. J. Bacteriol. 182: 5082-5090 [Abstract] [Full Text]  
• Franco, A. A., Cheng, R. K., Chung, G.-T., Wu, S., Oh, H.-B., Sears, C. L. (1999). Molecular Evolution of the Pathogenicity Island of Enterotoxigenic Bacteroides fragilis Strains. J. Bacteriol. 181: 6623-6633 [Abstract] [Full Text]  
• Vedantam, G., Novicki, T. J., Hecht, D. W. (1999). Bacteroides fragilis Transfer Factor Tn5520: the Smallest Bacterial Mobilizable Transposon Containing Single Integrase and Mobilization Genes That Function in Escherichia coli. J. Bacteriol. 181: 2564-2571 [Abstract] [Full Text]  
• Sitailo, L. A., Zagariya, A. M., Arnold, P. J., Vedantam, G., Hecht, D. W. (1998). The Bacteroides fragilis BtgA Mobilization Protein Binds to the oriT Region of pBFTM10. J. Bacteriol. 180: 4922-4928 [Abstract] [Full Text]