Abstract
In Staphylococcus aureus, mecA and femA are the genetic determinants of methicillin resistance. By using a multiplex PCR strategy, 310- and 686-bp regions of the mecA and femA genes, respectively, were coamplified to identify susceptible (lacking mecA) and resistant (mecA+) staphylococci and to differentiate S. aureus (femA+) from coagulase-negative staphylococci (lacking femA). A third staphylococcal genomic sequence, corresponding to IS431 and spanning 444 bp, was used as a PCR control. One hundred sixty-five staphylococcal strains were tested. All 72 methicillin-resistant strains were found to be mecA+, and 92 of the 93 susceptible isolates lacked mecA. Only one coagulase-negative Staphylococcus isolate carrying the mecA gene was highly susceptible to oxacillin. The femA determinant was a unique feature of S. aureus; it was found in 100% of the S. aureus strains tested but was undetectable in all of the coagulase-negative staphylococci tested. The possibility of directly detecting the mecA and femA genes in blood samples was also investigated. After two amplification steps, a sensitivity of 50 microorganisms per ml of freshly collected spiked blood was achieved. In conclusion, coamplification of mecA and femA determinants proved to be very reliable both for rapid detection of methicillin resistance and differential diagnosis between S. aureus and other staphylococci. This technique, which can be successfully performed with blood samples, could be a useful tool in the diagnosis and treatment monitoring of staphylococcal infections.
Full Text
The Full Text of this article is available as a PDF (264.1 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Barberis-Maino L., Berger-Bächi B., Weber H., Beck W. D., Kayser F. H. IS431, a staphylococcal insertion sequence-like element related to IS26 from Proteus vulgaris. Gene. 1987;59(1):107–113. doi: 10.1016/0378-1119(87)90271-x. [DOI] [PubMed] [Google Scholar]
- Berger-Bächi B., Barberis-Maino L., Strässle A., Kayser F. H. FemA, a host-mediated factor essential for methicillin resistance in Staphylococcus aureus: molecular cloning and characterization. Mol Gen Genet. 1989 Oct;219(1-2):263–269. doi: 10.1007/BF00261186. [DOI] [PubMed] [Google Scholar]
- Brown D. F., Brown L. Evaluation of the E test, a novel method of quantifying antimicrobial activity. J Antimicrob Chemother. 1991 Feb;27(2):185–190. doi: 10.1093/jac/27.2.185. [DOI] [PubMed] [Google Scholar]
- Christensen G. D., Bisno A. L., Parisi J. T., McLaughlin B., Hester M. G., Luther R. W. Nosocomial septicemia due to multiply antibiotic-resistant Staphylococcus epidermidis. Ann Intern Med. 1982 Jan;96(1):1–10. doi: 10.7326/0003-4819-96-1-1. [DOI] [PubMed] [Google Scholar]
- Davies J. Inactivation of antibiotics and the dissemination of resistance genes. Science. 1994 Apr 15;264(5157):375–382. doi: 10.1126/science.8153624. [DOI] [PubMed] [Google Scholar]
- Geha D. J., Uhl J. R., Gustaferro C. A., Persing D. H. Multiplex PCR for identification of methicillin-resistant staphylococci in the clinical laboratory. J Clin Microbiol. 1994 Jul;32(7):1768–1772. doi: 10.1128/jcm.32.7.1768-1772.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gerberding J. L., Miick C., Liu H. H., Chambers H. F. Comparison of conventional susceptibility tests with direct detection of penicillin-binding protein 2a in borderline oxacillin-resistant strains of Staphylococcus aureus. Antimicrob Agents Chemother. 1991 Dec;35(12):2574–2579. doi: 10.1128/aac.35.12.2574. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hackbarth C. J., Chambers H. F. Methicillin-resistant staphylococci: genetics and mechanisms of resistance. Antimicrob Agents Chemother. 1989 Jul;33(7):991–994. doi: 10.1128/aac.33.7.991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hürlimann-Dalel R. L., Ryffel C., Kayser F. H., Berger-Bächi B. Survey of the methicillin resistance-associated genes mecA, mecR1-mecI, and femA-femB in clinical isolates of methicillin-resistant Staphylococcus aureus. Antimicrob Agents Chemother. 1992 Dec;36(12):2617–2621. doi: 10.1128/aac.36.12.2617. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Leclercq R., Derlot E., Duval J., Courvalin P. Plasmid-mediated resistance to vancomycin and teicoplanin in Enterococcus faecium. N Engl J Med. 1988 Jul 21;319(3):157–161. doi: 10.1056/NEJM198807213190307. [DOI] [PubMed] [Google Scholar]
- Maccanti O., Bonadio M. Activity of vancomycin against recently isolated nosocomial gram-positive cocci. Drugs Exp Clin Res. 1992;18(7):295–297. [PubMed] [Google Scholar]
- Mulligan M. E., Murray-Leisure K. A., Ribner B. S., Standiford H. C., John J. F., Korvick J. A., Kauffman C. A., Yu V. L. Methicillin-resistant Staphylococcus aureus: a consensus review of the microbiology, pathogenesis, and epidemiology with implications for prevention and management. Am J Med. 1993 Mar;94(3):313–328. doi: 10.1016/0002-9343(93)90063-u. [DOI] [PubMed] [Google Scholar]
- Murakami K., Minamide W., Wada K., Nakamura E., Teraoka H., Watanabe S. Identification of methicillin-resistant strains of staphylococci by polymerase chain reaction. J Clin Microbiol. 1991 Oct;29(10):2240–2244. doi: 10.1128/jcm.29.10.2240-2244.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Murray B. E. New aspects of antimicrobial resistance and the resulting therapeutic dilemmas. J Infect Dis. 1991 Jun;163(6):1184–1194. [PubMed] [Google Scholar]
- Noble W. C., Virani Z., Cree R. G. Co-transfer of vancomycin and other resistance genes from Enterococcus faecalis NCTC 12201 to Staphylococcus aureus. FEMS Microbiol Lett. 1992 Jun 1;72(2):195–198. doi: 10.1016/0378-1097(92)90528-v. [DOI] [PubMed] [Google Scholar]
- Phillips L. G., Heggers J. P., Robson M. C. Burn and trauma units as sources of methicillin-resistant Staphylococcus aureus. J Burn Care Rehabil. 1992 Mar-Apr;13(2 Pt 2):293–297. doi: 10.1097/00004630-199203000-00023. [DOI] [PubMed] [Google Scholar]
- Predari S. C., Ligozzi M., Fontana R. Genotypic identification of methicillin-resistant coagulase-negative staphylococci by polymerase chain reaction. Antimicrob Agents Chemother. 1991 Dec;35(12):2568–2573. doi: 10.1128/aac.35.12.2568. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ryffel C., Tesch W., Birch-Machin I., Reynolds P. E., Barberis-Maino L., Kayser F. H., Berger-Bächi B. Sequence comparison of mecA genes isolated from methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis. Gene. 1990 Sep 28;94(1):137–138. doi: 10.1016/0378-1119(90)90481-6. [DOI] [PubMed] [Google Scholar]
- Schwalbe R. S., Stapleton J. T., Gilligan P. H. Emergence of vancomycin resistance in coagulase-negative staphylococci. N Engl J Med. 1987 Apr 9;316(15):927–931. doi: 10.1056/NEJM198704093161507. [DOI] [PubMed] [Google Scholar]
- Suzuki E., Hiramatsu K., Yokota T. Survey of methicillin-resistant clinical strains of coagulase-negative staphylococci for mecA gene distribution. Antimicrob Agents Chemother. 1992 Feb;36(2):429–434. doi: 10.1128/aac.36.2.429. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Suzuki E., Kuwahara-Arai K., Richardson J. F., Hiramatsu K. Distribution of mec regulator genes in methicillin-resistant Staphylococcus clinical strains. Antimicrob Agents Chemother. 1993 Jun;37(6):1219–1226. doi: 10.1128/aac.37.6.1219. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Turnidge J., Grayson M. L. Optimum treatment of staphylococcal infections. Drugs. 1993 Mar;45(3):353–366. doi: 10.2165/00003495-199345030-00004. [DOI] [PubMed] [Google Scholar]
- Unal S., Hoskins J., Flokowitsch J. E., Wu C. Y., Preston D. A., Skatrud P. L. Detection of methicillin-resistant staphylococci by using the polymerase chain reaction. J Clin Microbiol. 1992 Jul;30(7):1685–1691. doi: 10.1128/jcm.30.7.1685-1691.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]