Gut colonization with vancomycin-resistant and risk for subsequent enteric infection.

BACKGROUND

Gut colonization with vancomycin-resistant (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 . 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 species (p = 0.03) and viral (p = 0.04) enteric infections. In 716 patients who underwent testing, there was a trend towards more 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 infection, effects which persisted during 5 years of follow-up. Among positive tests, there was a greater proportion of with VRE (57% vs 28%, p < 0.01).

CONCLUSIONS

VRE colonization was associated with a decreased risk of subsequent non- enteric infection. VRE domination of the gut microbiome may protect against acquisition of common enteric pathogens.