Analysis of Borderline‐Resistant Strains of Methicillin‐Resistant Staphylococcus aureus Using Polymerase Chain Reaction

Abstract

Identification of methicillin‐resistant Staphylococcus aureus by drug‐susceptibility tests alone poses a serious problem, because a considerable number of clinical S. aureus isolates are borderline resistant to methicillin. To circumvent this problem, we have developed a quick and sensitive method of PCR amplification for the detection of mecA gene, which, coding for PBP2′, is the specific genetic element of methicillin‐resistant Staphylococcus aureus. This method made it possible to identify MRSA strains in a short time using as few as 30 cells as a starting material for template DNA. Using this method, we found that the strains of borderline methicillin‐resistance could be accurately identified. We also found one S. aureus clinical strain, T3, which lacked mecA gene in spite of its resistance to methicillin. © owned by Center for Academic Publications Japan (Publisher)