Gut colonization with vancomycin-resistant <italic>Enterococcus</italic> and risk for subsequent enteric infection.

Background: Gut colonization with vancomycin-resistant <italic>Enterococcus</italic> (VRE) is associated with poor outcomes. This study evaluated the impact of VRE colonization on subsequent acquisition of enteric pathogens. Methods: We performed a retrospective cohort study of adults admitted to an ICU from 2012 to 2017 who were screened for VRE colonization and subsequently underwent stool testing with a gastrointestinal pathogen PCR panel (GI PCR) with or without PCR testing for <italic>Clostridium difficile</italic>. Our primary outcome was the presence of any enteric pathogen. Cox proportional hazards modeling was used to adjust for factors associated with enteric infection. Results: Of 761 patients who underwent VRE screening and subsequent GI PCR, 131 (17%) were colonized with VRE. Patients with VRE colonization were less likely to test positive on GI PCR compared to patients without VRE (9.2% vs 18%, p = 0.01); specifically for <italic>E. coli</italic> species (p = 0.03) and viral (p = 0.04) enteric infections. In 716 patients who underwent <italic>C. difficile</italic> testing, there was a trend towards more <italic>C. difficile</italic> infections in patients colonized with VRE (15% vs 10%, p = 0.11). On multivariable analysis, patients with VRE had a decreased risk of a positive GI PCR (aHR 0.47, 95% CI 0.25–0.88, p = 0.02) but not <italic>C. difficile</italic> infection, effects which persisted during 5 years of follow-up. Among positive tests, there was a greater proportion of <italic>C. difficile</italic> with VRE (57% vs 28%, p < 0.01). Conclusions: VRE colonization was associated with a decreased risk of subsequent non-<italic>C. difficile</italic> enteric infection. VRE domination of the gut microbiome may protect against acquisition of common enteric pathogens. [ABSTRACT FROM AUTHOR]