Table 2.

Discrepancies between the MRSA-Screen test,mecA gene detection by PCR, and phenotypic tests for the detection of methicillin resistance among 200 S. aureusclinical isolates

No. of isolatesResulta for:
MRSA-ScreenbmecA gene detectionOxacillin disk diffusioncOxacillin-salt agar screend
1+e
4+− (2), + (2)
20++− (14), + (6)
  • a +, resistant; −, susceptible.

  • b Agglutination.

  • c Inhibition zone diameters were ≤10 mm for resistant isolates and ≥13 mm for susceptible isolates.

  • d Growth indicated resistance; no growth indicated susceptibility. The number of isolates with each result is given in parentheses after the symbol.

  • e This isolate, when retested, gave no agglutination.