Abstract
Objectives:Chlorhexidine is used as a disinfectant to prevent surgical infections. Recently, studies have indicated that chlorhexidine usagehas selected methicillin-resistant Staphylococcus aureus strains that aretolerant to chlorhexidine and that this may be related to the presence of the qacA/B-encoded efflux pumps. Here, we evaluated if high-level exposure to chlorhexidine selects for tolerant colonizing Staphylococcus epidermidis and we addressed the consequences of long-term exposure to chlorhexidine.Methods: Chlorhexidine susceptibility and carriage of qacA/Bwas determined for colonizing S. epidermidis isolated fromscrub nurses heavily exposed to chlorhexidine andwere compared with isolates fromnon-users of chlorhexidine hand rubs. S. epidermidis blood isolates from the 1960s, before the wider introduction of chlorhexidine to the market, were also tested and compared with recently collected S. epidermidis blood isolates. Results:There was no correlation between the use of chlorhexidine in scrub nurses and the presence of qacA/B genes in S. epidermidis isolates or increased MICs/MBCs of chlorhexidine for S. epidermidis isolates. While 55% of current blood isolates harboured the qacA/B genes, none of the 33 historical S. epidermidis isolates did, although their MICs and MBCs of chlorhexidine were comparable to those for current isolates.Conclusions: Chlorhexidine used as a hand rub does not select for S. epidermidis isolates with increased MICs or MBCs of chlorhexidine. However, the absence of qacA/B genes in S. epidermidis isolates obtained in the 1960s suggests that long-term use of biocides like chlorhexidine or related compoundsmayselect for the presence of qacA/B genes.
| Original language | English |
|---|---|
| Journal | The Journal of antimicrobial chemotherapy |
| Volume | 68 |
| Issue number | 10 |
| Pages (from-to) | 2226-2233 |
| Number of pages | 8 |
| ISSN | 0305-7453 |
| DOIs | |
| Publication status | Published - Oct 2013 |