Prevalence of antimicrobial resistance in fecal Escherichia coli isolates from stray pet dogs and hospitalized pet dogs in Korea.

A total of 628 Escherichia coli isolates recovered from 877 intestinal samples of stray pet dogs (n = 565) and hospitalized pet dogs (n = 312) in Korea were analyzed for resistance to 15 antimicrobial agents. Most common resistance observed in E. coli isolated from both groups of dogs was to tetracycline (52.4-53.6%), streptomycin (35.8-41.7%), ampicillin (32.9-47.1%), nalidixic acid (21.6-37.4%), and trimethoprim/sulfamethoxazole (19.7-36.4%). Resistance to chloramphenicol, gentamicin, and ciprofloxacin was observed in 19.4% (17.1-24.3%), 18% (16.1-21.8%), and 16.1% (13.5-21.4%) of the isolates, respectively. No E. coli isolated from hospitalized dogs showed resistance to imipenem and cefepime, whereas three (0.7%) isolates from stray dogs were resistant to cefepime. Some of the isolates from both groups showed resistance to cefotaxime (2.4-3.9%) and amikacin (0.5-1.5%). In general, the frequency of resistance tended to be higher in isolates from hospitalized dogs than isolates from stray dogs against most antimicrobials tested. Around 39% (162/422) and 27% (55/206) of E. coli isolates from stray dogs and hospitalized dogs were susceptible to all antimicrobials tested, respectively. Multiresistance (> or = 3 subclasses of antimicrobials) was observed in 32% and 48% of E. coli isolates from stray dogs and hospitalized dogs, respectively. More attention should be paid to the use of antimicrobials and the occurrence of antimicrobial resistance in companion animals.