Affiliation:
1. Department of Pediatrics, Section of Infectious Diseases, Baylor College of Medicine, Houston, Texas, USA
Abstract
ABSTRACT
One of the strategies utilized to decrease infections in the hospital setting relies on topical antimicrobials and antiseptics. While their use is beneficial, concerns arise over the potential to develop resistance or tolerance to these agents. We examined nosocomial
Staphylococcus aureus
isolates from 2007 to 2013 for the presence of genes associated with tolerance to chlorhexidine. Isolates and patients were identified from an
S. aureus
surveillance study at Texas Children's Hospital. Nosocomial
S. aureus
isolates (those causing infection at ≥72 h of hospitalization) were identified and underwent PCR for the
qacA
or
qacB
(
qacA/B
) and
smr
genes associated with elevated minimum bactericidal concentrations of chlorhexidine. Molecular typing with pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and
agr
typing and a review of the medical record were performed. Two hundred forty-seven nosocomial
S. aureus
infections were identified. Overall, 111 isolates carried one or both genes (44.9%); 33.1% were positive for
smr
, 22.7% were positive for
qacA/B
, and 10.9% of the isolates possessed both genes. The
smr
-positive isolates were more often resistant to methicillin, ciprofloxacin, and/or clindamycin. The isolates positive for
qacA/B
were more often associated with indwelling central venous catheters and a vancomycin MIC of ≥2 μg/ml. Isolates carrying either
smr
or
qacA/B
were associated with a diagnosis of bacteremia. The
smr
-positive isolates more often belonged to sequence type 8 (ST8) than the isolates that were positive for
qacA/B
. Mupirocin resistance was detected in 2.8% of the isolates. Antiseptic-tolerant
S. aureus
strains are common in our children's hospital and are associated with decreased susceptibility to other systemic antimicrobials and with bloodstream infections. Further work is needed to understand the implications that these organisms have on the hospital environment and antiseptic use in the future.
Funder
HHS | NIH | National Institute of Allergy and Infectious Diseases
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Pharmacology (medical),Pharmacology
Cited by
38 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献