Faecal carriage and acquisition of Extended-Spectrum Beta-Lactamase (ESBL)-producing Enterobacteriaceae in dogs, cats and humans: prevalence, risk factors, and co-carriage.

Background Faecal carriage with ESBL-producing Enterobacteriacea (ESBL-E) has been observed in pets, but prevalence, risk factors and co-carriage between cats, dogs and humans have not been determined rigorously. Objectives To determine prevalence, persistence and risk factors for carriage with ESBL-E in healthy dogs, cats and humans. Methods In a nationwide study, Dutch residents, one person per household, were randomly invited to complete a questionnaire and to submit a faecal sample. Dog and cat owners were invited to also submit a faecal sample of dog or cat. Repeated sampling after 1 and 6 months was performed in a subset. ESBL-E were obtained through selective culture and characterized by whole genome sequencing. Logistic regression analyses and random forest models were performed to identify risk factors. Results The prevalence of ESBL-E carriage in these cohorts was 3.8% (95%CI: 2.7%-5.4%) for human participants (n=550), 10.7% (95%CI: 8.3%-13.7%) for dogs (n=555) and 1.4% (95%CI: 0.5-3.8) for cats (n=285). Among animals blaCTX-M-1 was most abundant, followed by blaCTX-M-15. In dogs persistence of carriage was 57.1% at 1 month and 42.9% at six months. Eating raw meat (OR:8.8, 95%CI:4.7-16.4; PAR:46.5%, 95%CI:41.3-49.3) and dry food (OR:0.2, 95%CI:0.1-0.5; PAR:56.5%, 95%CI:33.2-66.6) were predictors for ESBL-E carriage in dogs. Human-dog co-carriage with identical ESBL-genes was demonstrated in five households. Human-cat co-carriage was not observed. Conclusion Within the same household ESBL-E prevalence was higher in dogs than in humans and lower in cats. The main risk factor for ESBL-E carriage was eating raw meat. Co-carriage in dogs and household members was uncommon.