title: Value of Xpert MRSA/SA blood culture assay on the Gene Xpert® Dx System for rapid detection of Staphylococcus aureus and coagulase-negative staphylococci in patients with staphylococcal bacteremia.
abstract: The Xpert MRSA/SA BC assay was examined prospectively in patients with staphylococcal bacteremia including 6 patients with blood culture bottles inoculated with biological fluid (synovial fluid in 4 cases and peritoneal fluid in 2 cases). Among the 56 Staphylococci species isolated, 80.3% were coagulase-negative staphylococci (CoNS) and 19.7% were S. aureus. Methicillin susceptibility test results showed that 77.8% of isolates were methicillin-resistant CoNS (MRCoNS) and 22.2% of isolates were methicillin-susceptible CoNS (MSCoNS). Of 11 S. aureus isolates, 63.7% were methicillin-susceptible S. aureus (MSSA) and 36.3% were methicillin-resistant S. aureus (MRSA). Xpert MRSA/SA BC results showed that genotypic results were in concordance with phenotypic results in 94.6% of cases versus 5.4% of discordant cases. Of these 3 discordant cases, 1 S. aureus isolate had an MRSA phenotype and an SPA(+)mec(+)SCCmec(-) genotype and another S. aureus isolate was phenotypically MSSA and genotypically SPA(+)mec(+)SCCmec(-), and 1 S. epidermidis isolate was phenotypically MSCoNS and genotypically SPA(-)mec(+)SCCmec(-).
authors.affiliation: Laboratoire de Bactériologie, CHU Nord, Place Victor Pauchet, AMIENS Cedex 1, France. Biendo.Maurice@chu-amiens.fr
authors.forename: Maurice
authors.initials: M
authors.lastname: Biendo
authors.forename: Hedi
authors.initials: H
authors.lastname: Mammeri
authors.forename: Emilie
authors.initials: E
authors.lastname: Pluquet
authors.forename: Hélène
authors.initials: H
authors.lastname: Guillon
authors.forename: Florence
authors.initials: F
authors.lastname: Rousseau
authors.forename: Brigitte
authors.initials: B
authors.lastname: Canarelli
authors.forename: Mohamed
authors.initials: M
authors.lastname: Belmekki
authors.forename: François
authors.initials: F
authors.lastname: Eb
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001202:Ascitic Fluid / Q000382:microbiology; D016470:Bacteremia / Q000175:diagnosis / Q000382:microbiology*; D001431:Bacteriological Techniques / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification; D008875:Middle Aged; D058889:Molecular Typing / Q000379:methods*; D010641:Phenotype; D011446:Prospective Studies; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification*; D013582:Synovial Fluid / Q000382:microbiology