Carbapenemase Producing Enterobacteriaceae isolated from yellow-legged gulls (Larus michahellis) from south of France, may 2022. Enterobacteriaceae

In the next decades, the antimicrobial resistance will become one of the major threats to human health. Studying these determinants via a "One Health" approach is essential to highlight the antimicrobial resistance transmission pathways. In this study, we characterized the carriage of Carbapenemase-Producing Enterobacteriaceae (CPE) in a colony of Yellow-legged Gulls (Larus michahellis), a wild bird species exposed to human sources of antimicrobial resistance through their feeding behavior, they are foraging in landfills, they are living near high density urban areas. They are thus known to be reservoirs of human antimicrobial resistance. After isolation of CPE-strains, all these isolates were sequenced either by Illumina and Oxford Nanopore methods. Thus, we identified a high prevalence of carriage in the colony (8.93%). Two gulls were carriers of OXA-48-producing strains on IncL-plasmids, in particular E. coli belonging to high-risk STs (ST10, ST648). Eight other gulls were carriers of IMI-4 or NMC-A producing-Enterobacter cloacae complex. Those carbapenemase genes are mainly described form aquatic origin. They were chromosomally integrated on integrative mobile elements (EcloIMEX), in STs already described in humans. Overall, these data suggest that these wildbirds can act as vectors for CPEs of both human and environmental origin, disseminating these strains as they migrate, and potentially exposing humans to clinically relevant antimicrobial resistance genes.