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. 1979 Sep;25(3):902–911. doi: 10.1128/iai.25.3.902-911.1979

Genetics of staphylococcal enterotoxin B in methicillin-resistant isolates of Staphylococcus aureus.

W M Shafer, J J Iandolo
PMCID: PMC414533  PMID: 259057

Abstract

Biophysical and genetic analysis of staphylococcal enterotoxin B (SEB) synthesis in 16 methicillin-resistant (Mecr) Staphylococcus aureus isolates demonstrated that the toxin gene (entB) can occupy either a plasmid or chromosomal locus. Biophysical analysis of the plasmid deoxyribonucleic acid content of these strains by agarose gel electrophoresis revealed the presence of a 1.15-megadalton plasmid in six isolates that appears to contain the entB gene. Genetic manipulation of SEB synthesis by transduction and elimination procedures demonstrated that this plasmid is critical for enterotoxigenesis. Nevertheless, the majority of the Mecr SEB+ isolates (62.5%) analyzed in this investigation were found to lack the 1.15-megadalton plasmid. In at least two of these strains (COL and 57-dk), transduction and elimination procedures showed that entB was chromosomal. Genetic studies involving strains harboring either a plasmid or chromosomal entB gene demonstrated that toxin synthesis was coeliminated with mec. However, analysis of the entB and mec loci by transformation or transduction showed that the genes are not closely linked. On the other hand, transduction of entB, regardless of the donor, was observed when both mec and the Tcr plasmid were jointly cotransduced. This finding suggests that, during transduction, a transient association between entB, mec, and the Tcr plasmid may exist.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bjorn M. J., Vasil M. L., Sadoff J. C., Iglewski B. H. Incidence of exotoxin production by Pseudomonas species. Infect Immun. 1977 Apr;16(1):362–366. doi: 10.1128/iai.16.1.362-366.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Cohen S., Sweeney H. M. Transduction of Methicillin Resistance in Staphylococcus aureus Dependent on an Unusual Specificity of the Recipient Strain. J Bacteriol. 1970 Dec;104(3):1158–1167. doi: 10.1128/jb.104.3.1158-1167.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Dornbusch K., Hallander H. O., Löfquist F. Extrachromosomal control of methicillin resistance and toxin production in Staphylococcus aureus. J Bacteriol. 1969 May;98(2):351–358. doi: 10.1128/jb.98.2.351-358.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Dornbusch K., Hallander H. O. Transduction of penicillinase production and methicillin resistance-enterotoxin B production in strains of Staphylococcus aureus. J Gen Microbiol. 1973 May;76(1):1–11. doi: 10.1099/00221287-76-1-1. [DOI] [PubMed] [Google Scholar]
  5. Iandolo J. J., Shafer W. M. Regulation of staphylococcal enterotoxin B. Infect Immun. 1977 May;16(2):610–616. doi: 10.1128/iai.16.2.610-616.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Kayser F. H., Wüst J., Santanam P. Genetic and molecular characterisation of resistance determinants in methicillin-resistant Staphylococcus-aureus. J Med Microbiol. 1976 May;9(2):137–148. doi: 10.1099/00222615-9-2-137. [DOI] [PubMed] [Google Scholar]
  7. Klaenhammer T. R., McKay L. L., Baldwin K. A. Improved lysis of group N streptococci for isolation and rapid characterization of plasmid deoxyribonucleic acid. Appl Environ Microbiol. 1978 Mar;35(3):592–600. doi: 10.1128/aem.35.3.592-600.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Kuhl S. A., Pattee P. A., Baldwin J. N. Chromosomal map location of the methicillin resistance determinant in Staphylococcus aureus. J Bacteriol. 1978 Aug;135(2):460–465. doi: 10.1128/jb.135.2.460-465.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Lacey R. W. Antibiotic resistance plasmids of Staphylococcus aureus and their clinical importance. Bacteriol Rev. 1975 Mar;39(1):1–32. doi: 10.1128/br.39.1.1-32.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Lacey R. W. Staphylococcus aureus strain DU4916--an atypical methicillin-resistant isolate? J Gen Microbiol. 1974 Sep;84(1):1–10. doi: 10.1099/00221287-84-1-1. [DOI] [PubMed] [Google Scholar]
  11. Löfdahl S., Sjöström J. E., Philipson L. Characterization of small plasmids from Staphylococcus aureus. Gene. 1978 Apr;3(2):145–159. [PubMed] [Google Scholar]
  12. Meyers J. A., Sanchez D., Elwell L. P., Falkow S. Simple agarose gel electrophoretic method for the identification and characterization of plasmid deoxyribonucleic acid. J Bacteriol. 1976 Sep;127(3):1529–1537. doi: 10.1128/jb.127.3.1529-1537.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. NOVICK R. P. ANALYSIS BY TRANSDUCTION OF MUTATIONS AFFECTING PENICILLINASE FORMATION IN STAPHYLOCOCCUS AUREUS. J Gen Microbiol. 1963 Oct;33:121–136. doi: 10.1099/00221287-33-1-121. [DOI] [PubMed] [Google Scholar]
  14. Novick R. P., Bouanchaud D. The problems of drug-resistant pathogenic bacteria. Extrachromosomal nature of drug resistance in Staphylococcus aureus. Ann N Y Acad Sci. 1971 Jun 11;182:279–294. doi: 10.1111/j.1749-6632.1971.tb30664.x. [DOI] [PubMed] [Google Scholar]
  15. Pariza M. W., Iandolo J. J. Base ratio and deoxyribonucleic acid homology studies of six Staphylococcus aureus typing bacteriophages. Appl Microbiol. 1974 Feb;27(2):317–323. doi: 10.1128/am.27.2.317-323.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Shafer W. M., Iandolo J. J. Chromosomal locus for staphylococcal enterotoxin B. Infect Immun. 1978 Apr;20(1):273–278. doi: 10.1128/iai.20.1.273-278.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Shafer W. M., Iandolo J. J. Staphylococcal enterotoxin A: a chromosomal gene product. Appl Environ Microbiol. 1978 Aug;36(2):389–391. doi: 10.1128/aem.36.2.389-391.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Shalita Z., Hertman I., Sarid S. Isolation and characterization of a plasmid involved with enterotoxin B production in Staphylococcus aureus. J Bacteriol. 1977 Jan;129(1):317–325. doi: 10.1128/jb.129.1.317-325.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Sjöström J. E., Löfdahl S., Philipson L. Transformation reveals a chromosomal locus of the gene(s) for methicillin resistance in Staphylococcus aureus. J Bacteriol. 1975 Sep;123(3):905–915. doi: 10.1128/jb.123.3.905-915.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Smith K., Novick R. P. Genetic studies on plasmid-linked cadmium resistance in Staphylococcus aureus. J Bacteriol. 1972 Nov;112(2):761–772. doi: 10.1128/jb.112.2.761-772.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Stiffler P. W., Sweeney H. M., Cohen S. Absence of circular plasmid deoxyribonucleic acid attributable to a genetic determinant for methicillin resistance in Staphylococcus aureus. J Bacteriol. 1973 Nov;116(2):771–777. doi: 10.1128/jb.116.2.771-777.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Wyman L., Goering R. V., Novick R. P. Genetic control of chromosomal and plasmid recombination in Staphylococcus aureus. Genetics. 1974 Apr;76(4):681–702. doi: 10.1093/genetics/76.4.681. [DOI] [PMC free article] [PubMed] [Google Scholar]

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