Extensive dissemination of ESBL-producing Clonal Complex 14 Escherichia coli is likely spread through sexual transmission among men who have sex with men at risk of sexually transmitted infections.

Objectives: We characterized the genetic proximity of Sequence Type (ST) 131, 1193 and 14 Extended-Spectrum Beta-Lactamase-producing E. coli (ESBL-Ec) to assess human determinants of carriage in community settings.

Methods: In this cross-sectional study, we included individuals seeking care at a sexually transmitted infection (STI) or HIV outpatient clinic. ESBL-Ec were compared using phylogeny, core-genome Multi-Locus Sequence Typing and Single-Nucleotide Polymorphism (SNP) determination. Determinants were compared between STs and correlated to genetic distances.

Results: 103 individuals carried 112 strains of ST131 (n=63), ST14 (n=26) and ST1193 (n=23). Compared to ST131, ST14 isolates were more commonly found in individuals with any STI (p=0.031), men who have sex with men (p<0.001) and recent antibiotic use (p=0.021); whereas ST1193 isolates were more commonly found in individuals who engaged in insertive anal sex in <6 months (p=0.017). ST131 isolates showed high genomic diversity, while other STs evidenced a high level of proximity. SNPs data indicated the likely spread of a single ST14 (range=1;32) and some ST1193 clusters (range=2;111), which were linked to ST-specific sexual behaviors.

Conclusions: In populations of those at risk of acquiring STI, ST14 and ST1193 ESBL-Ec are emerging. Specific sexual transmissions routes are likely to play a role in their spread.