The indiscriminate use of antibiotics during the past 50 yr in human and veterinary medicine and agriculture has enhanced the selection of antimicrobial resistant bacteria (AMRB) and genes (ARG), representing a serious threat to public health worldwide. Wildlife can act as reservoirs of antimicrobial resistant (AMR) environmental pollution, contributing to the dissemination of AMRB and ARG, especially in aquatic environments impacted by anthropogenic activities. The objective of this study was to evaluate the role of the coypu (Myocastor coypus), an invasive semiaquatic species, as an ecologic sentinel of AMR in the wetlands of Catalonia, Spain. A total of 116 free-living coypu were analyzed to detect the presence of AMRB and determine their antimicrobial susceptibility profile, and to detect the carriage of extended-spectrum β-lactamase and colistin resistance genes by conventional PCR. Resistant bacteria were detected in 16.3% of the samples (n=19), belonging to Aeromonas spp. (31.5%), Pseudomonas spp. (26.3%), and Enterobacterales (42.1%), with Escherichia coli (26.3%) as the principal enterobacterium. Most isolates showed AMR to aminopenicillins, lincosamides, and third-generation cephalosporins. Conversely, all isolates were sensitive to carbapenems. Analysis of ARG revealed 32% (6/19) of strains were positive for the blaCMY-2 gene (three isolates of E. coli, two of Pseudomonas spp., and one of Aeromonas hydrophila). These findings reinforce the value of testing invasive species such as coypus as bioindicators of AMR in environmental surveillance programs.
Seminati et al. (Mon,) studied this question.