In Staphylococcus aureus, mecA and femA are the genetic determinants of methicillin
resistance. By using a multiplex PCR strategy, 310-and 686-bp regions of the mecA and
femA genes, respectively, were coamplified to identify susceptible (lacking mecA) and
resistant (mecA+) staphylococci and to differentiate S. aureus (femA+) from coagulase-
negative staphylococci (lacking femA). A third staphylococcal genomic sequence,
corresponding to IS431 and spanning 444 bp, was used as a PCR control. One hundred …

Vannuffel and coworkers (1) offer an interesting approach to the problem of rapid and
specific detection of methicillinresistant Staphylococcus aureus in clinical specimens. This
approach is based on the premise that methicillin-resistant S. aureus strains harbor both
mecA and femA genes, while methicillin-resistant coagulase-negative staphylococci (CNS)
carry the mecA gene only. The authors detect both genes directly in clinical samples (eg,
blood samples) by multiplex PCR and claim that this simultaneous detection identifies both …