Colonization With Multidrug-Resistant Organisms Among Healthy Adults in the Community Setting: Prevalence, Risk Factors, and Composition of Gut Microbiome

Background: The prevalence of colonization with multidrug-resistant organisms (MDROs) among healthy adults in the community is largely unknown. This study investigated the colonization rate of multidrug-resistant , methicillin-resistant (MRSA), and vancomycin-resistant enterococci (VRE) in the community in Taiwan, and compared the gut microbiota between MDRO carriers and non-carriers.

Methods: This prospective cohort study was conducted from March 2017 to February 2018 at the Hsin-Chu and Jin-Shan branches of National Taiwan University Hospital. Nasal swabs and stool samples were obtained from healthy adults attending a health examination to screen for MDROs. Bacteria isolates of MDROs were tested for antibiotic susceptibility and resistant genes. Relevant data were collected using a standardized questionnaire to evaluate the risk factors for MDROs carriage, and 16S rRNA metagenomics sequencing was performed to analyze gut microbiota.

Results: Among 187 participants, 4.6% (8/174) carried MRSA and 41.4% (77/186) carried third-generation cephalosporin-resistant (3GC-R) or . The carriage rate of AmpC beta-lactamases and ESBL-producing strains were 16.1 and 27.4%, respectively. No carbapenem-resistant (CRE) or VRE were detected. The dominant resistant gene of isolates was CTX-M-type (73%), while that of was AmpC beta-lactamases (80%). In the multivariate analysis, the significant risk factors for carrying 3GC-R or were being an employee of technology company A [adjusted odds ratio (aOR) 4.127; 95% confidence interval (CI) 1.824-9.336; = 0.001], and traveling to Southeast Asia in the past year (aOR 6.545; 95% CI 1.071-40.001; = 0.042). The gut microbiota analysis showed that the phylum and the family were significantly more abundant in 3GC-R and carriers.

Conclusion: A high rate of Taiwanese adults in the community carried 3GC-R , while no CRE or VRE colonization was noted. Compared with non-carriers, an expansion of in gut microbiota was found among 3GC-R carriers.