The association between biocide tolerance and the presence or absence of qac genes among hospital-acquired and community-acquired MRSA isolates

Biocides commonly used in the hospital environment should be effective against clinical isolates of S. aureus if used at concentrations recommended by the manufacturer. However, isolates have the potential to develop increased tolerance to these agents and the expression of Qac efflux pumps results in isolates with a selective advantage when challenged with biocides containing QACs and chlorhexidine gluconate.