A new multiplex PCR-based reverse line-blot hybridization (mPCR/RLB) assay for rapid staphylococcal cassette chromosome mec (SCCmec) typing

J Med Microbiol. 2009 Aug;58(Pt 8):1045-1057. doi: 10.1099/jmm.0.007955-0. Epub 2009 Jun 15.

Abstract

The aim of this study was to develop a new discriminatory method for MRSA SCCmec typing based on multiplex PCR-based reverse line-blot hybridization (mPCR/RLB) assay to enable rapid identification and classification of MRSA SCCmec types in a clinical laboratory. Forty-five primer sets and 49 probes were designed and tested in uniplex PCR (uPCR) and mPCR/RLB. Probes were compared in silico to 14 whole-genome sequences and 18 partial SCCmec gene sequences of Staphylococcus aureus and complete genome and partial SCCmec genes of seven non-MRSA strains, including meticillin-susceptible S. aureus and meticillin-resistant coagulase-negative staphylococci. The method was tested on a set of 42 well-characterized reference MRSA strains. It identified all five epidemiologically relevant SCCmec types and 26 subtypes, including established and new subtypes of SCCmec III, IV (eight subtypes each) and V (three subtypes). The discriminatory power of mPCR/RLB SCCmec typing was similar to that of MLST and spa typing (Simpson indices of diversity of 0.916, 0.926 and 0.882, respectively; differences not statistically significant). The application of mPCR/RLB hybridization assay to MRSA SCCmec typing can improve the specificity, discriminatory power and throughput of the typing procedure. The detection of up to 43 mPCR products in a single hybridization assay transforms MRSA SCCmec typing from passive epidemiological library typing into a potential tool for near-real-time infection control surveillance and tracking of MRSA transmission in hospitals.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Typing Techniques / methods*
  • Base Sequence
  • Chromosomes, Bacterial / genetics*
  • DNA, Bacterial / genetics
  • Genotype
  • Methicillin / pharmacology
  • Methicillin Resistance / genetics
  • Methicillin-Resistant Staphylococcus aureus / genetics*
  • Nucleic Acid Hybridization / methods*
  • Phylogeny
  • Polymerase Chain Reaction / methods*

Substances

  • Anti-Bacterial Agents
  • DNA, Bacterial
  • Methicillin