High proportion of wrongly identified methicillin-resistant Staphylococcus aureus carriers by use of a rapid commercial PCR assay due to presence of staphylococcal cassette chromosome element lacking the mecA gene

J Clin Microbiol. 2011 Feb;49(2):722-4. doi: 10.1128/JCM.01988-10. Epub 2010 Dec 15.

Abstract

During a 9-month period, 217 patients were newly diagnosed as methicillin-resistant Staphylococcus aureus (MRSA) carriers by using a commercial rapid PCR-based test (GeneXpert). However, no MRSA was recovered by culturing the second swab in 61 of these patients. Further analyses showed that 28 (12.9%) of the patients harbored S. aureus isolates with a staphylococcal cassette chromosome element lacking the mecA gene and were thus incorrectly determined to be MRSA carriers.

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacteriological Techniques / methods*
  • Carrier State / diagnosis
  • Carrier State / microbiology
  • DNA, Bacterial / genetics*
  • False Positive Reactions*
  • Humans
  • Methicillin-Resistant Staphylococcus aureus / genetics
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification*
  • Penicillin-Binding Proteins
  • Polymerase Chain Reaction / methods*
  • Staphylococcal Infections / diagnosis*
  • Staphylococcal Infections / microbiology

Substances

  • Bacterial Proteins
  • DNA, Bacterial
  • Penicillin-Binding Proteins
  • mecA protein, Staphylococcus aureus