Multicenter evaluation of the Xpert MRSA NxG Assay for detection of methicillin resistant Staphylococcus aureus in nasal swabs.

Related Articles

Multicenter evaluation of the Xpert MRSA NxG Assay for detection of methicillin resistant Staphylococcus aureus in nasal swabs.

J Clin Microbiol. 2017 Nov 08;:

Authors: Yarbrough ML, Warren DK, Allen K, Burkholder D, Daum R, Donskey C, Knaack D, LaMarca A, May L, Miller LG, Parenti DM, Peterson L, Tan TY, Widen R, Hernandez DR, Wolk DM, Burnham CA

Abstract
Healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) infections are a burden on the healthcare system. Clinical laboratories play a key role in reducing this burden, as timely identification of MRSA colonization or infection facilitates infection control practices that are effective at limiting invasive MRSA infections. The Xpert MRSA NxG Assay recently received FDA clearance for the direct detection of MRSA from nasal swabs. This multicenter study evaluated the clinical performance characteristics of the Xpert MRSA NxG Assay with prospectively collected rayon nasal swabs (n = 1103) and flocked swab (ESwab) nasal specimens (n = 846). Culture-based identification methods and antimicrobial susceptibility testing were used as the reference standard for comparison. According to the reference method, the positivity rate of MRSA in the population evaluated was 11.1% (122/1103) for rayon swabs and 11.6% (98/846) for flocked swabs. The overall sensitivity and specificity of the rayon swabs was 91.0% (95% CI: 84.6-94.9%) and 96.9% (95% CI: 95.7-97.8%), respectively across eight testing sites. The flocked swab specimens were 92.9% (86.0-96.5%) sensitive and 97.6% (95% CI: 96.2-98.5%) specific for MRSA detection across six testing sites. The sensitivity and specificity of the combined flocked and rayon swab data were 91.8% (95% CI: 87.4-94.8%) and 97.2% (95% CI: 96.3-97.9%), respectively. The positive predictive value (PPV) of rayon swabs was 78.7% versus 83.5% for ESwabs. The negative predictive value (NPV) of rayon swabs and ESwab specimens was 98.9% and 99.1%, respectively. In conclusion, the Xpert MRSA NxG Assay is a sensitive and specific assay for the direct detection of MRSA from nasal swab specimens.

PMID: 29118165 [PubMed - as supplied by publisher]

http://ift.tt/2zwAEkD