563. Association Between Chlorhexidine Gluconate Concentrations and Resistant Bacterial Bioburden on Skin

Abstract

BackgroundLittle research exists to guide optimal Chlorhexidine gluconate (CHG) bathing practices. We examined the association between CHG concentrations and methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Enterobacteriaceae (CRE), and vancomycin-resistant Enterococcus (VRE) on the skin. Also, we studied whether bioburden is affected by bathing method (2% CHG cloth vs. 4% liquid CHG soap) and time since last CHG bath.MethodsPatients with MRSA, CRE and VRE at 4 US hospitals were enrolled. Skin swabs (arm, chest) were collected to quantify bioburden and CHG concentrations. Information on bathing method and time since last CHG bath was collected. χ 2 test, Spearman’s correlation, and linear regression were performed.Results253 patients were enrolled. On arm skin, MRSA was detected in 17 (19%), CRE on 16 (12%), and VRE on 12 (21%) patients. Detectable CHG levels were observed in 82 (93%) MRSA, 81 (79%) CRE, and 44 (79%) VRE patients. A negative correlation was observed between bioburden and CHG concentration for MRSA (rs = −0.11, P = 0.28) and CRE (rs = −0.02, P = 0.82) while a positive correlation was observed for VRE (rs = 0.15, P = 0.28). On chest skin, MRSA was detected in 25 (28%), CRE on 18 (12%), and VRE on 7 (13%) patients. Detectable CHG levels were observed in 83 (95.4%) MRSA, 78 (72%) CRE, and 43 (77%) VRE patients. MRSA bioburden was negatively correlated with CHG concentration (rs = −0.16, P = 0.12), while a positive correlation was noted for CRE (rs = 0.18, P = 0.06) and VRE (rs =0.24, P = 0.06). There was no significant difference in bacterial bioburden between CHG concentrations (>20 ppm vs. ≤20 ppm) at both skin sites (Table 1). The bioburden did not differ by method of CHG bath. The mean estimates of bacterial bioburden on both skin sites did not show a significant decrease with increase in CHG concentrations and were not affected by time since last bath (Table 2).ConclusionDetection of MRSA, CRE and VRE was infrequent irrespective of CHG bathing method and time since last bath. We found inconsistent associations between increasing CHG concentrations and bacterial bioburden. CHG bathing frequency may be optimized for individual patient populations to augment the reduction of bacteria. Additional research to understand the association of CHG skin concentrations and resistant bacterial burden is required. Disclosures All authors: No reported disclosures.