Isolated Bacteria and Their Antimicrobial Susceptibility through Urine Culture Obtained from Companion Animals in Japan

Abstract

It is important to understand the current results concerning isolated bacteria and their antimicrobial susceptibility through urine cultures to perform diagnosis and treatment of urinary tract infections among ill companion animals. However, there are very few investigations regarding the data of urine cultures based on nationwide-surveillance in Japan. The purpose of this study was to determine species identification of the bacteria and their antimicrobial susceptibility through urine cultures obtained from the animals with a nationwide approach. We analyzed the nationwide-surveillance data of bacterial identification and drug susceptibility by standard methods with urine specimens collected from approximate 1,000 animal clinics/ hospitals from 1 st August 2014 to 31 st July 2016 (for two years). Of 6,179 urine samples collected, there were 5,246 bacterial strains isolated from the 3,941 specimens. The most prevalent species identified were Escherichia coli (34.4%)/ Staphylococcus intermedius group (12.9%)/ Enterococcus faecalis (10.2%)/ Klebsiella pneumoniae (6.6%)/ Proteus mirabilis (5.8%)/ Pseudomonas aeruginosa (4.0%)/ Enterococcus faecium (4.0%)/Group G Streptococci (3.2%)/Coagulase-negative Staphylococci (2.2%)/ Enterobacter cloacae (1.7%), indicating that the total proportion was 85.0% of all isolated bacteria. We found that the rate of methicillin-resistant Staphylococci (MRS) was 57.6% among the isolates from the S. intermedius group. We also observed that the detection rates of extended-spectrum β -lactamase (ESBL) were E. coli 42.3%/ K. pneumoniae 63.3%/ P. mirabilis 20.3% among the Enterobacteriaceae isolates from 1 st August 2015 through 31 st July 2016. Carbapenem-resistant strains, multidrug-resistant P . aeruginosa , and vancomycin-resistant strains were not detected. Just as in human infections, the floral bacteria in the rectum were highly isolated from the animalsʼ urine, and the proportions of MRS and ESBL-producing Enterobacteriaceae isolates were high-level. Our observations indicate the current characteristics of antimicrobial resistance among the urine-origin isolates from the animals, suggesting that we should promote antimicrobial stewardships in the animal clinical setting.