International Spread of Multidrug-Resistant Campylobacter coli in Men Who Have Sex with Men in Washington State and Quebec, 2015-2018

Background: Campylobacter spp. are among the most common causes of enteric bacterial infections worldwide. Men who have sex with men (MSM) are at increased risk for sexually-transmitted enteric infections, including globally-distributed strains of multidrug-resistant Shigella spp. Methods: Retrospective study of MSM-associated Campylobacter in Seattle and Montreal with phenotypic antimicrobial resistance profiles and whole genome sequencing. Findings: We report the isolation of two clonal lineages of multi-drug-resistant Campylobacter coli from MSM in Seattle, Washington and Montreal, Quebec. Whole genome sequencing revealed nearly identical strains obtained from the two regions over a four-year period. Comparison with large genomic databases revealed extensive Campylobacter spp. clusters carrying multiple drug resistance genes that segregated with these isolates. Examination of the genetic basis of antimicrobial resistance revealed multiple macrolide resistance determinants including a novel ribosomal RNA methyltransferase situated in a CRISPR array locus in a Campylobacter coli isolate. Interpretation: As previously reported for Shigella, specific multi-drug-resistant strains of Campylobacter are circulating by sexual transmission in MSM populations across diverse geographic locations, suggesting a need to incorporate sexual behavior in the investigation of clusters of foodborne pathogens revealed by whole-genome sequence data. Funding Statement: University of Washington Department of Laboratory Medicine. Declaration of Interests: F.C.F. reports consulting fees and non-financial support from BioFire. No other competing interests for the other authors. Ethics Approval Statement: This study was approved by the University of Washington Institutional Review Board and the Centre hospitalier de l'Universite de Montreal Research Ethics Committee.