1株新ST型猪链球菌的分离鉴定

Characteristics of a novel strain of Streptococcus suis

从健康仔猪鼻腔分离到1株血清8型猪链球菌,基因型为mrp-efsly+,命名为RC4726。对青霉素类、头孢菌素类、磺胺类、喹诺酮类药物敏感,对红霉素、阿齐霉素、克林霉素和四环素耐药,MIC值分别为0.5 mg/mL,2 mg/mL,0.5 mg/mL,4 mg/mL。4×108CFU不能使C57BL6小鼠发病。MLST结果显示,RC4726的7个管家基因的座位分别为18,34,24,12,1,1,4。试验结果表明RC4726是一个新ST型,属于非致病性猪链球菌。

A Streptococcus suis serotype 8 strain was isolated from the nasal cavity of piglets, named as RC4726. The strain was mrp^-efsly^＋. RC4726 strain was resistant to erythromycin,azithromycin, clindamycin and tetracycline, with MIC value was 0.5 mg/mL, 2 mg/mL, 0.5 mg/mL, 4 mg/mL, respectively, but sensitive to penicillin, cephalosporins, sulfanilamide group. C57BL6 mice challenged with 4× 10^8CFU RC4726 did not show clinical signs while SC84 caused sudden death in mice. The allelic profile of RC4726 was 18, 34, 24, 12, 1, 1, 4. The results demonstrated that RC4726 was a novel strain of S. suis without virulence.