Background: Chlorhexidine gluconate (CHG) use has been shown to decrease rates of healthcare associated infections. S. aureus possessing either the smr or qacA/B genes are associated with decreased susceptibility to CHG and other antiseptics. Previous studies of antiseptic tolerant staphylococci have largely focused on high-risk populations and the exact role of healthcare exposure on acquisition of these organisms is unclear. We sought to describe the risk factors and features of infection caused by antiseptic tolerant S. aureus in a general pediatric population.
Methods: Isolates were selected from the prospective S. aureus surveillance study ongoing at Texas Childrens Hospital. Every third sequential isolate in the year 2014 was selected for inclusion. All isolates underwent PCR for the genes qacA/B and smr. Medical records were reviewed. Statistical analyses were performed with the assistance of STATA ver 13.
Results: 506 isolates were included in the study with 74.3% being community-acquired and 75.1% soft-tissue infections. 19.8% of isolates were smr-positive and 15.6% qacA/B-positive. smr-positive isolates were associated with the diagnosis of surgical site infection, CHG exposure and treatment failure (Figure 1). qacA/B-positive infections were more often associated with bacteremia, any underlying medical condition, nosocomial acquisition, the presence of CVLs, ICU admission and death (Figure 2). Isolates bearing both smr and qacA/B were more often seen in patients previously exposed to CHG (30.7%, p=0.02). Among patients with an antiseptic tolerant infection, 45.8% lacked any underlying conditions, CVLs, CHG exposure or hospitalization/surgery in the prior 3 months.
Conclusion: Antiseptic tolerant S. aureus are common in our community and associated with nosocomial acquisition, CVLs, prior CHG exposure and underlying medical conditions as well as worse clinical outcomes. These findings imply the role of the healthcare environment in acquisition of these organisms. Nearly half of patients with infection caused by these organisms, however, lack typical risk factors for a healthcare associated infection. These data suggest that while healthcare exposure is an important risk factor, these organism are prevalent in the community as well.
Site-Co-investigator on clinical trial that is unrelated to research presented
E. O. Mason Jr., None
S. L. Kaplan, Forest Labs: Grant Investigator , Research support and Site-PI for clinical trial unrelated to presented research
Pfizer: Grant Investigator , Research grant
Cubist: Grant Investigator , Research grant and Site-PI for clinical trial unrelated to presented research
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