title: A rapid and high-throughput screening approach for methicillin-resistant Staphylococcus aureus based on the combination of two different real-time PCR assays.
abstract: Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen that has been responsible for major nosocomial epidemics worldwide. For infection control programs, rapid and adequate detection of MRSA is of great importance. We developed a rapid and high-throughput molecular screening approach that consists of an overnight selective broth enrichment, followed by mecA, mecC, and S. aureus-specific (SA442 gene) real-time PCR assays, with subsequent confirmation using a staphylococcal cassette chromosome mec element (SCCmec)-orfX-based real-time PCR assay (GeneOhm MRSA assay) and culture. Here, the results of the screening approach over a 2-year period are presented. During this period, a total of 13,387 samples were analyzed for the presence of MRSA, 2.6% of which were reported as MRSA positive. No MRSA isolates carrying the mecC gene were detected during this study. Based on the results of the real-time PCR assays only, 95.2% of the samples could be reported as negative within 24 h. Furthermore, the performance of these real-time PCR assays was evaluated using a set of 104 assorted MRSA isolates, which demonstrated high sensitivity for both the combination of mecA and mecC with SA442 and the BD GeneOhm MRSA assay (98.1% and 97.1%, respectively). This molecular screening approach proved to be an accurate method for obtaining reliable negative results within 24 h after arrival at the laboratory and contributes to improvement of infection control programs, especially in areas with a low MRSA prevalence.
authors.affiliation: Department of Medical Microbiology and Medical Immunology, Rijnstate Hospital, Velp, The Netherlands rnijhuis@rijnstate.nl.
authors.forename: Roel H T
authors.initials: RH
authors.lastname: Nijhuis
authors.affiliation: Department of Medical Microbiology and Medical Immunology, Rijnstate Hospital, Velp, The Netherlands.
authors.forename: Noortje M
authors.initials: NM
authors.lastname: van Maarseveen
authors.affiliation: Laboratory of Medical Microbiology and Immunology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors.forename: Erik J
authors.initials: EJ
authors.lastname: van Hannen
authors.affiliation: Department of Medical Microbiology and Medical Immunology, Rijnstate Hospital, Velp, The Netherlands.
authors.forename: Anton A
authors.initials: AA
authors.lastname: van Zwet
authors.affiliation: Department of Medical Microbiology and Medical Immunology, Rijnstate Hospital, Velp, The Netherlands.
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Mascini
mesh_terms: D057166:High-Throughput Screening Assays; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification*; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D011237:Predictive Value of Tests; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis*; D013997:Time Factors