Authors: S Roisin C Laurent C Nonhoff A Deplano M Hallin B Byl M J Struelens O Denis
Publish Date: 2011/08/28
Volume: 31, Issue: 5, Pages: 873-880
Abstract
The purpose of this study was to assess the accuracy of the Xpert MRSA assay XP for the detection of methicillinresistant Staphylococcus aureus MRSA carriage upon hospital admission Nasal swabs were prospectively collected for MRSA screening from 1891 patients admitted to a teaching hospital XP results were compared to chromogenic agar culture results MRSA was cultured in 61 specimens 3 Compared with culture XP had a sensitivity specificity positive and negative predictive value of 607 973 378 and 989 respectively The median turnaround time TAT for the results was 3 h Of 24 MRSA isolated from XPnegative samples three harbored composite SCCmec Among 61 samples with culturenegative but XPpositive results 15 methicillinsusceptible S aureus MSSA isolates tested positive by XP on pure colony lysates These MSSA included i strains with SCCmec deletion encompassing mecA and ii multilocus sequence typing MLST clonal complex CC 1 strains harboring a chromosomal sequence homologous to one of the orfX–SCCmec junction sequences targeted by XP On account of the low sensitivity and positive predictive value in a hospital patient population with moderate prevalence of MRSA culture still appears to be necessary in order to confirm polymerase chain reaction PCR results The emergence of new SCCmec variants and the presence of MSSA harboring crossreactive SCCmeclike elements may challenge the successful implementation of such detection systemsThis work was supported by a grant from the Belgian Antibiotic Policy Coordination Committee BAPCOC Ministry of Public Health Belgium and was organized under the auspices of the Federal Platform for Hospital Hygiene The XP system and some of the reagents were kindly provided by Cepheid Europe MaurensScopont France
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