Abstract
Conjugal transposons play an important role in the dissemination of antibiotic resistance determinants in the streptococci and have been postulated to exist in Bacteroides fragilis. To investigate the presence of conjugal transposons in B. fragilis, we employed a Tra- derivative of the transfer factor pBFTM10 contained in the chimeric plasmid pGAT400 delta BglII. We attempted to restore transferability to this plasmid from a series of transconjugants generated by crossing B. fragilis TMP230 containing the TET transfer factor with B. fragilis TM4000, a standard recipient. Transconjugant TM4.2321 transferred pGAT400 delta BglII to Escherichia coli HB101 at almost the same frequency as did the Tra+ parental plasmid, pGAT400. Analysis of the transferred plasmids revealed the presence of 9.6 kilobases of additional DNA in every case but at different positions in independent isolates. The presence of this DNA, designated Tn4399, allowed the pGAT400 delta BglII derivatives to retransfer from the TM4000 background to B. fragilis or E. coli recipients. DNA hybridization studies demonstrated the presence of one copy of Tn4399 in TMP230 and three copies at new sites in TM4.2321. Tn4399 is a new B. fragilis transposon with unique transfer properties that may play a role in the dissemination of drug resistance genes. It differs from previously described conjugal transposons by its ability to mobilize nonconjugal plasmids in cis.
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- Birnboim H. C., Doly J. A rapid alkaline extraction procedure for screening recombinant plasmid DNA. Nucleic Acids Res. 1979 Nov 24;7(6):1513–1523. doi: 10.1093/nar/7.6.1513. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Clewell D. B., Gawron-Burke C. Conjugative transposons and the dissemination of antibiotic resistance in streptococci. Annu Rev Microbiol. 1986;40:635–659. doi: 10.1146/annurev.mi.40.100186.003223. [DOI] [PubMed] [Google Scholar]
- Clewell D. B., Helinski D. R. Properties of a supercoiled deoxyribonucleic acid-protein relaxation complex and strand specificity of the relaxation event. Biochemistry. 1970 Oct 27;9(22):4428–4440. doi: 10.1021/bi00824a026. [DOI] [PubMed] [Google Scholar]
- Courvalin P., Carlier C. Tn1545: a conjugative shuttle transposon. Mol Gen Genet. 1987 Feb;206(2):259–264. doi: 10.1007/BF00333582. [DOI] [PubMed] [Google Scholar]
- Franke A. E., Clewell D. B. Evidence for a chromosome-borne resistance transposon (Tn916) in Streptococcus faecalis that is capable of "conjugal" transfer in the absence of a conjugative plasmid. J Bacteriol. 1981 Jan;145(1):494–502. doi: 10.1128/jb.145.1.494-502.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Guiney D. G., Hasegawa P., Davis C. E. Plasmid transfer from Escherichia coli to Bacteroides fragilis: differential expression of antibiotic resistance phenotypes. Proc Natl Acad Sci U S A. 1984 Nov;81(22):7203–7206. doi: 10.1073/pnas.81.22.7203. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Guiney D. G., Jr Promiscuous transfer of drug resistance in gram-negative bacteria. J Infect Dis. 1984 Mar;149(3):320–329. doi: 10.1093/infdis/149.3.320. [DOI] [PubMed] [Google Scholar]
- Guyer M. S. The gamma delta sequence of F is an insertion sequence. J Mol Biol. 1978 Dec 15;126(3):347–365. doi: 10.1016/0022-2836(78)90045-1. [DOI] [PubMed] [Google Scholar]
- Malamy M. H., Tally F. P. Mechanisms of drug-resistance transfer in Bacteroides fragilis. J Antimicrob Chemother. 1981 Dec;8 (Suppl 500):59–75. doi: 10.1093/jac/8.suppl_d.59. [DOI] [PubMed] [Google Scholar]
- Marsh P. K., Malamy M. H., Shimell M. J., Tally F. P. Sequence homology of clindamycin resistance determinants in clinical isolates of Bacteroides spp. Antimicrob Agents Chemother. 1983 May;23(5):726–730. doi: 10.1128/aac.23.5.726. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mays T. D., Smith C. J., Welch R. A., Delfini C., Macrina F. L. Novel antibiotic resistance transfer in Bacteroides. Antimicrob Agents Chemother. 1982 Jan;21(1):110–118. doi: 10.1128/aac.21.1.110. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Odelson D. A., Rasmussen J. L., Smith C. J., Macrina F. L. Extrachromosomal systems and gene transmission in anaerobic bacteria. Plasmid. 1987 Mar;17(2):87–109. doi: 10.1016/0147-619x(87)90016-3. [DOI] [PubMed] [Google Scholar]
- Privitera G., Dublanchet A., Sebald M. Transfer of multiple antibiotic resistance between subspecies of Bacteroides fragilis. J Infect Dis. 1979 Jan;139(1):97–101. doi: 10.1093/infdis/139.1.97. [DOI] [PubMed] [Google Scholar]
- Rashtchian A., Dubes G. R., Booth S. J. Tetracycline-inducible transfer of tetracycline resistance in Bacteroides fragilis in the absence of detectable plasmid DNA. J Bacteriol. 1982 Apr;150(1):141–147. doi: 10.1128/jb.150.1.141-147.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robillard N. J., Tally F. P., Malamy M. H. Tn4400, a compound transposon isolated from Bacteroides fragilis, functions in Escherichia coli. J Bacteriol. 1985 Dec;164(3):1248–1255. doi: 10.1128/jb.164.3.1248-1255.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Salyers A. A., Shoemaker N. B., Guthrie E. P. Recent advances in Bacteroides genetics. Crit Rev Microbiol. 1987;14(1):49–71. doi: 10.3109/10408418709104435. [DOI] [PubMed] [Google Scholar]
- Scott J. R., Kirchman P. A., Caparon M. G. An intermediate in transposition of the conjugative transposon Tn916. Proc Natl Acad Sci U S A. 1988 Jul;85(13):4809–4813. doi: 10.1073/pnas.85.13.4809. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shoemaker N. B., Guthrie E. P., Salyers A. A., Gardner J. F. Evidence that the clindamycin-erythromycin resistance gene of Bacteroides plasmid pBF4 is on a transposable element. J Bacteriol. 1985 May;162(2):626–632. doi: 10.1128/jb.162.2.626-632.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smith C. J., Macrina F. L. Large transmissible clindamycin resistance plasmid in Bacteroides ovatus. J Bacteriol. 1984 May;158(2):739–741. doi: 10.1128/jb.158.2.739-741.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Southern E. M. Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol. 1975 Nov 5;98(3):503–517. doi: 10.1016/s0022-2836(75)80083-0. [DOI] [PubMed] [Google Scholar]
- Tally F. P., Snydman D. R., Gorbach S. L., Malamy M. H. Plasmid-mediated, transferable resistance to clindamycin and erythromycin in Bacteroides fragilis. J Infect Dis. 1979 Jan;139(1):83–88. doi: 10.1093/infdis/139.1.83. [DOI] [PubMed] [Google Scholar]
- Vijayakumar M. N., Priebe S. D., Guild W. R. Structure of a conjugative element in Streptococcus pneumoniae. J Bacteriol. 1986 Jun;166(3):978–984. doi: 10.1128/jb.166.3.978-984.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Welch R. A., Macrina F. L. Physical characterization of Bacteroides fragilis R plasmid pBF4. J Bacteriol. 1981 Feb;145(2):867–872. doi: 10.1128/jb.145.2.867-872.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]


