Prevalence and antimicrobial susceptibility of Enterococcus spp. from urine of dogs and cats in northwestern Croatia.

This study investigated the prevalence and antimicrobial susceptibility of enterococci isolated from dogs and cats with urinary tract infections in northwestern Croatia. During this study, the laboratory received 787 urine samples, 651 from dogs and 136 from cats. A total of 260 urine samples (211 from dogs and 49 from cats) were bacteriologically positive. Of these, 29 isolates belonged to Enterococcus spp.; 22 from dogs and seven from cats. Enterococci isolates were identified by PCR method, 12 of which were Enterococcus faecium and 17 were Enterococcus faecalis species. In dogs, 16 E. faecalis and six E. faecium strains were identified, whereas in cats, six E. faecium and only one E. faecalis strain were identified. Antimicrobial susceptibility was determined by the Kirby-Bauer disk diffusion method for nine antimicrobials: penicillin, ampicillin, vancomycin, nitrofurantoin, rifampicin, tetracycline, chloramphenicol, enrofloxacin, ciprofloxacin. The isolates were tested for high-level resistance to streptomycin and gentamicin. The highest resistance of Enterococcus spp. was observed to rifampicin (86%) and enrofloxacin (83%), followed by tetracycline and ciprofloxacin (69%). Resistance to vancomycin was 28%, and the lowest resistance was to chloramphenicol (17%). Multidrug resistance was found in 76% of enterococci isolates. High-level streptomycin resistance was detected in 17% and high-level gentamicin resistance in 10% of the isolated enterococci. When comparing species susceptibility, E. faecium isolates were significantly more resistant to penicillin, ampicillin, nitrofurantoin, and ciprofloxacin (p < 0.05). Eleven E. faecium isolates (92%) and 12 E. faecalis isolates (76%) were multidrug resistant.