Concordance of PCR and Culture from Nasal Swabs for Detection of Methicillin-Resistant Staphylococcus aureus in a Setting of Concurrent Antistaphylococcal Antibiotics

The effect of concurrent administration of antibiotics on the detection of methicillin-resistantStaphylococcus aureus (MRSA) remains unresolved. Here, we assessed the concordance of paired nasal swabs processed using commercial PCR and culture and found high concordance in both the absence and presence of antibiotics with activity against MRSA (93.7% [95% confidence interval [CI], 88.1%, 96.8%] and 90.9% [95% CI, 84.8%, 94.7%], respectively), although PCR was more likely to be positive in the presence of antibiotics. (This study has been registered atClinicalTrials.gov under registration no. NCT01234831.)