Antimicrobial resistance of bacterial isolates from positive urine culture in four hundred five dogs between 2013-2014

We collected urine samples from dogs admitted to a South Korean referral animal hospital for diagnostic procedures. The samples were cultured and investigated for antimicrobial resistance. A total of 469 bacterial strains from 405 dogs were isolated and subjected to antimicrobial susceptibility testing. A total of 158 (33.7%) and 311 (66.3%) gram positive and negative bacterial strains, respectively, were identified. Bacterial strains identified included Escherichia coli (32.8%), Staphylococcus spp. (17.9%), Enterococcus spp. (12.4%), and Proteus mirabilis (11.9%). The multi-drug resistance rate for the entire bacterial population was 82.3%; the rates for E. coli and Staphylococcus spp. were 80.5% and 67.9%, respectively. Coagulase-negative Staphylococcus spp. accounted for 88.1% with multi-drug resistance rate of 68.9%. Imipenem, amikacin, chloramphenicol, amoxicillin/clavulanic acid, and norfloxacin (in decreasing order) had the greatest impact factors on the bacterial populations. Considering the impact factor of individual antimicrobial drugs and resistance rates for each bacterial strain in this study, amoxicillin-clavulanic acid may be recommended as a first-line drug for urinary tract infection. However, multi-drug resistance rates were high.; Therefore, bacterial culture and antimicrobial susceptibility tests should always be performed.