Antimicrobial Resistance in Bacteria Isolated from Exotic Pets: The Situation in the Iberian Peninsula

Literature related to antimicrobial resistant (AMR) bacteria in exotic pets is minimal, being essential to report objective data on this topic, which represents a therapeutic challenge for veterinary medicine and public health. Between 2016 and 2020, laboratory records of 3156 exotic pet specimens’ microbiological diagnoses and antibiotic susceptibility testing (AST) results were examined. The samples were classified into three animal classes: birds (<i>n</i> = 412), mammalia (<i>n</i> = 2399), and reptilian (<i>n</i> = 345). The most prevalent bacteria in birds and mammals were <i>Staphylococcus</i> spp. (15% and 16%), while in reptiles they were <i>Pseudomonas</i> spp. (23%). Pseudomonas was the genus with the highest levels of AMR in all animal groups, followed by <i>Enterococcus</i> spp. By contrast, Gram-positive cocci and <i>Pasteurella</i> spp. were the most sensitive bacteria. Moreover, in reptiles, <i>Stenotrophomonas</i> spp., <i>Morganella</i> spp., and <i>Acinetobacter</i> spp. presented high levels of AMR. Multidrug-resistant (MDR) bacteria were isolates from reptiles (21%), birds (17%), and mammals (15%). The Enterobacterales had the highest MDR levels: <i>S. marcescens</i> (94.4%), <i>C. freundii</i> (50%), <i>M. morganii</i> (47.4%), <i>K. pneumoniae</i> (46.6%), <i>E. cloacae</i> (44%), and <i>E. coli</i> (38.3%). The prevalence of MDR <i>P. aeruginosa</i> strains was 8%, detecting one isolate with an XDR profile. Regarding antimicrobial use, many antibiotics described as critically important for human use had significant AMR prevalence in bacteria isolated from exotic pets. Under the One-Health approach, these results are alarming and of public health concern since potential transmission of AMR bacteria and genes can occur from exotic pets to their owners in both senses. For this reason, the collaboration between veterinarians and public health professionals is crucial.