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. 1981 Feb;145(2):867–872. doi: 10.1128/jb.145.2.867-872.1981

Physical characterization of Bacteroides fragilis R plasmid pBF4.

R A Welch, F L Macrina
PMCID: PMC217191  PMID: 6257654

Abstract

Bacteroides fragilis V479-1 has previously been shown to harbor a self-transmissible 27 X 10(6)-dalton plasmid (pBF4) which confers lincosamide-macrolide resistance. The present study has focused on the physical properties of pBF4. The plasmid was found to be present in 1 to 2 copies per chromosomal equivalent. pBF4 was genetically stable, although spontaneously occurring plasmidless segregants could be detected at low frequency (approximately 1%). This frequency was unaffected by growth of cells in ethidium bromide. About one-third of all spontaneously occurring macrolide-lincosamide-sensitive clones of strain V479-1 were found to contain pBF4 molecules that carried deletions. Ten independently obtained deletion derivatives of pBF4 from lincosamide-macrolide-sensitive strains were compared with the parental pBF4 by restriction endonuclease cleavage analysis. A restriction site map of pBF4 was constructed, and the location of the deletions was approximated. Self-annealed pBF4 molecules, examined by electron microscopy, revealed the presence of two pairs of inverted repeat (IR) sequences on the plasmid. IR-1 was about 400 base pairs in length, and its two component members were separated by an intervening sequence of about 15 kilobases. IR-2 was about 75 base pairs in length, and its component members were separated by 4.2 kilobases. Each of the deletions of pBF4 studied had a terminus at or near the same IR-2 sequence.

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Selected References

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  1. Bartlett J. G., Sutter V. L., Finegold S. M. Treatment of anaerobic infections with lincomycin and clindamycin. N Engl J Med. 1972 Nov 16;287(20):1006–1010. doi: 10.1056/NEJM197211162872002. [DOI] [PubMed] [Google Scholar]
  2. Guerry P., LeBlanc D. J., Falkow S. General method for the isolation of plasmid deoxyribonucleic acid. J Bacteriol. 1973 Nov;116(2):1064–1066. doi: 10.1128/jb.116.2.1064-1066.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Kleckner N. Translocatable elements in procaryotes. Cell. 1977 May;11(1):11–23. doi: 10.1016/0092-8674(77)90313-0. [DOI] [PubMed] [Google Scholar]
  4. Macrina F. L., Kopecko D. J., Jones K. R., Ayers D. J., McCowen S. M. A multiple plasmid-containing Escherichia coli strain: convenient source of size reference plasmid molecules. Plasmid. 1978 Jun;1(3):417–420. doi: 10.1016/0147-619x(78)90056-2. [DOI] [PubMed] [Google Scholar]
  5. 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]

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