TABLE 2.

Causes of discordance for samples initially identified as positive by IDI-MRSA PCR and negative by primary culture

Source of swabs with discordant resultsNo. of swabs
PCR positive, culture negativeaObtained from patients defined as MRSA positiveBroth enrichment culture positiveSame-day MRSA patient historyb
YesNoYesNo
Nasal plus axilla-groin-perineum711607
Perineum331221
Wound532314
  • a Culture negative, initial unenriched selective culture performed on MSA-FOX.

  • b Same-day history indicates that the patient was positive for MRSA from other specimens obtained on the same day.