High-level Colonization With Antibiotic-Resistant Enterobacterales Among Individuals in a Semi-Urban Setting in South India: An Antibiotic Resistance in Communities and Hospitals (ARCH) Study

BACKGROUND: Antimicrobial resistance poses a significant threat to public health globally. We studied the prevalence of colonization with extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE), carbapenem-resistant Enterobacterales (CRE), and colistin-resistant Enterobacterales (Col-RE) in hospitals and the surrounding community in South India. METHODS: Adults from 2 hospitals and the catchment community who consented to provide stool specimens were enrolled. Stools were plated on CHROMagar selective for ESCrE, CRE, and Col-RE. Bacterial identification and antibiotic susceptibility testing were done using Vitek 2 Compact and disc diffusion testing. Colistin broth microdilution was performed for a subset of isolates. Prevalence estimates were calculated with 95% confidence intervals (CIs), and differences were compared across populations using the Pearson χ(2) or Fisher exact test. RESULTS: Between November 2020 and March 2022, 757 adults in the community and 556 hospitalized adults were enrolled. ESCrE colonization prevalence was 71.5% (95% CI, 68.1%–74.6%) in the community and 81.8% (95% CI, 78.4%–84.8%) in the hospital, whereas CRE colonization prevalence was 15.1% (95% CI, 12.7%–17.8%) in the community and 22.7% (95% CI, 19.4%–26.3%) in the hospital. Col-RE colonization prevalence was estimated to be 1.1% (95% CI, .5%–2.1%) in the community and 0.5% (95% CI, .2%–1.6%) in the hospital. ESCrE and CRE colonization in hospital participants was significantly higher compared with community participants (P < .001 for both). CONCLUSIONS: High levels of colonization with antibiotic-resistant Enterobacterales were found in both community and hospital settings. This study highlights the importance of surveillance of colonization in these settings for understanding the burden of antimicrobial resistance.