FRANCOIS P, PITTET D, BENTO M, PEPEY B, VAUDAUX P, LEW DP, SCHRENZEL J; Interscience Conference on Antimicrobial Agents and Chemotherapy (42nd : 2002 : San Diego, Calif.).
Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2002 Sep 27-30; 42: abstract no. D-2007.
Geneva Univ. Hosp., Geneva, Switzerland
BACKGROUND: A procedure was developed for rapid detection and identification of MRSA directly from biological samples. METHODS: The method (qMRSA) consists in a S. aureus immuno-magnetic enrichment (90 min) followed by mechanical lysis with nucleic acid purification (90 min) and a fluorescent amplification/detection by triplex quantitative PCR (qPCR) (140 min). Our qPCR assay measured simultaneously: i) mecA gene, common to both S. aureus and S. epidermidis, ii) femA gene specific to S. aureus, and iii) femA gene specific to S. epidermidis. Fluorescent data were calibrated with four reference strains: one methicillin-susceptible S. aureus (MSSA), one MRSA, one methicillin-susceptible and one methicillin-resistant S. epidermidis. qMRSA was compared to an optimized culture procedure including broth enrichment. RESULTS: qMRSA allowed a sensitive detection of the measured mecA and femA signals, yielding specific and reproducible identification of MRSA. This 96-well assay allowed processing in <6 h 25 samples/run. We tested 50 patients whose samples originated from 5 different sources (nares, inguinal, or pooled swabs, urine and sputum). Whereas 23 culture-positive samples were positively detected by qMRSA, 11 culture-negative samples were also scored as positive by the qPCR. Interestingly, all these patients were either previously identified as MRSA carriers and/or were screened as MRSA culture-positive at any other sampling site during the same hospital stay. The superior sensitivity of qMRSA over culture might result from trace amounts of DNA released from bacteria killed by recent decontamination procedures. A similar quality performance of qMRSA was also obtained using the SmartCycler . CONCLUSIONS: This novel molecular assay is a promising procedure for detecting MRSA carriers within 6h and implementing prompt and cost-effective infection control measures.
Publication Types:
Keywords:
- Biological Assay
- Humans
- Infection Control
- Polymerase Chain Reaction
- Sensitivity and Specificity
- Staphylococcal Infections
- Staphylococcus aureus
Other ID:
UI: 102267467
From Meeting Abstracts