Carbapenemase-Producing Aeromonas veronii Disseminated in the Environment of an Equine Specialty Hospital

The emergence of bacterial resistance to carbapenem antibiotics is an urgent public health threat. Carbapenem drugs are a last resort treatment option for life-threatening infections. The frequent use of broad-spectrum antibiotics to treat hospitalized patients provides significant selection pressure favoring the emergence and dissemination of resistant organisms, including carbapenem-resistant Enterobacteriaceae (CRE). CREs have been reported in animal populations, but only rarely in horses. Our objective was to determine the prevalence of CRE in the environment of a referral equine specialty hospital. Environmental samples were collected on seven different sampling dates. Four clonal carbapenemase-producing Aeromonas veronii were recovered from 315 sampled surfaces (1.3%). All four isolates harbored the carbapenemase-producing, metallo-β-lactamase gene bla cphA , although corresponding minimum inhibitory concentrations were within the susceptible range for imipenem and meropenem. All had an identical multilocus sequence type with a previously unreported allelic profile and contained multiple plasmids. To our knowledge, this recovery of bla cphA -harboring A. veronii is the first report of carbapenemase-producing bacteria in the environment of an equine veterinary hospital. However, the low recovery rate suggests that environmental contamination is uncommon. Appropriate hospital cleaning and disinfection protocols are necessary to maintain a low risk of contamination for patients and personnel.