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

• Published in: Journal of Veterinary Medical Science Vol. 82; no. 1; pp. 9 - 13
• Main Authors: ICHIKAWA, Takashi, OSHIMA, Masaaki, YAMAGISHI, Junjiro, MURAMATSU, Chieko, ASAI, Tetsuo
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 01.01.2020; Japan Science and Technology Agency; The Japanese Society of Veterinary Science
• Subjects: Ampicillin; Antimicrobial agents; Antimicrobial resistance; Bacteriology; Cefotaxime; Chloramphenicol; Chloromycetin; Clarithromycin; Clindamycin; Endocarditis; Erythromycin; genotype; Genotypes; High resistance; Levofloxacin; Meropenem; Penicillin; phenotype; Phenotypes; pig; Strains (organisms); Streptococcus suis; Sulfamethoxazole; Swine; Trimethoprim; Vancomycin; Japan; phenotype; antimicrobial resistance; Streptococcus suis; genotype; pig
• ISSN: 0916-7250; 1347-7439
• DOI: 10.1292/jvms.19-0449

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