Prevalence of Antimicrobial Resistance in Escherichia coli Isolated from Retail Meat in Tokyo, Japan

This study aimed to survey the trend of antimicrobial resistance in Escherichia coli obtained from retail meat. We examined the susceptibilities of 1,115 E. coli isolates obtained from chicken, beef, pork, venison, and wild boar meat from 2011 to 2017 in Tokyo to 14 antimicrobials (ampicillin, cefotaxime (CTX), streptomycin, gentamicin, kanamycin, tetracycline (TC), chloramphenicol, nalidixic acid, ciprofloxacin, sulfamethoxazole-trimethoprim, fosfomycin, amikacin, imipenem, and meropenem). Of all the tested isolates, 18.7% (135/721) isolates from chicken, 77.0% (117/152) from beef, 46.6% (89/187) from pork, 100% (28/28) from venison, and 92.6% (25/27) from wild boar meat were susceptible to all tested antimicrobials. Furthermore, TC resistance was the most common, with rates as high as 56.7% (409/721) and 40.6% (76/187) in the isolates from chicken and pork, respectively. CTX resistance was detected in 4.9% (25/506) of the isolates from domestic chicken and 23.7% (51/215) of the isolates from imported chicken. Moreover, CTX resistance rate in isolates from domestic chicken was significantly lower in 2016 (0.9%, 1/111) and in 2017 (0.8%, 1/121) than in 2012 (10.6%, 17/161). In conclusion, E. coli isolates from retail meat were most commonly resistant to TC, and CTX resistance was higher in E. coli isolates from imported chicken than in E. coli isolates from domestic chicken.