Antimicrobial Susceptibility and Biochemical Characteristics of Streptococcus suis Isolated from Diseased Pigs in Gyeongbuk Province

Streptococcus suis is a worldwide pathogen of a variety of porcine infection and has also been de-scribed as a pathogen for humans. We studied biochemical characteristics, antimicrobial susceptibility, and identification of polymerase chain reaction (PCR) of S. suis isolated from diseased pigs in Gyeongbuk province from 2004 to 2009. Sixty-one isolates were identified as S. suis by biochemical characteristics and PCR from 40 farms. The biochemical characteristics of S. suis isolates were pro-duction of VP-negative, hippurate, esculin, and arginine decarboxylase-positive, and fermentation of carbohydrate was variable lactose, trehalose, inulin, and raffinose, which was typeable 11 phenotype. In an antimicrobial susceptibility test, the majority of isolates were highly susceptible to amox-icillin/clavulanic acid, ampicillin, cephalothin, cefoperazone and florfenicol, while being highly re-sistant to streptomycin, kanamycin, amikacin, neomycin, erythromycin, clindamycin, and tetracycline. The isolates were divided into 11 phenotypes of biochemistry. By using PCR, the 16S-rRNA gene DNA fragment was detected at 304 bp from all of isolates. These results may provide the basic in-formation needed to establish strategies for the prevention of S. suis infection in pigs.Keywords : Streptococcus suis., antimicrobial susceptibility, biochemical characteristics, PCR