Changes in antimicrobial resistance phenotypes and genotypes in Streptococcus suis strains isolated from pigs in the Tokai area of Japan

摘要

strains isolated from porcine endocarditis and tonsils in the Tokai area of Japan during 2004–2007 and 2014–2016 (n=114) were tested for antimicrobialsusceptibility and distribution of selected resistance genes. No strains showed resistance to penicillin, ampicillin, cefotaxime, meropenem, vancomycin, and levofloxacin. High resistance totetracycline (80.7%), clindamycin (65.8%), erythromycin (56.1%), and clarithromycin (56.1%) was observed. In chloramphenicol and sulfamethoxazole-trimethoprim, there was a trend towardsincreased resistance between the first (2004–2007) and second (2014–2016) periods. (O) and (B) genes were the most frequently detected, and (M) and (A/E) genes were only detected in strains isolated during 2014–2016. These results indicate that chloramphenicol andsulfamethoxazole-trimethoprim resistance, and (M) and (A/E) genes emerged in of this area after 2014.