Antimicrobial susceptibility of bacterial isolates from urinary tract infections in companion animals in Spain

Background The increasing emergence of multidrug-resistant bacteria, causing urinary tract infections (UTI) in dogs and cats, represents a great therapeutic challenge and a public health concern. Methods Laboratory records of 4943 urinary microbiological diagnosis results and antimicrobial resistance profiles of suspected UTI cases in dogs and cats were analysed from 2016 to 2018 in Spain. Results This study showed a higher percentage of positive microbiological diagnoses in dogs (42%, 1368/3270) than in cats (27%, 457/1673). Although Escherichia coli was the most frequently isolated bacterium, the frequency of antimicrobial susceptibility of E. coli isolates was lower compared to other bacterial species like Enterococcus spp., Staphylococcus spp., Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter (E. cloacae), and Proteus mirabilis. The antimicrobial susceptibility testing of Gram-positive cocci showed higher levels of resistance in cats to common beta-lactams used for the treatment of complicated UTIs, as well as to fluoroquinolones, aminoglycosides, and carbapenems. Moreover, enterobacteria (E. coli, K. pneumoniae, and P. mirabilis) from cats presented high resistance frequencies to beta-lactams, including third- and fourth-generation cephalosporins and fluoroquinolones. Conclusion This study updates data on the current antimicrobial resistance in UTI bacteria from companion animals in Spain, which may help to guide clinicians for the appropriate use of antimicrobials.