猪链球菌宿主多样性调查

Survey on host diversity of Streptococcus suis

利用PCR方法对表观健康的猪肉、禽、鱼和狗随机抽取317份样品进行猪链球菌检测.结果显示,猪肉样品中4份呈阳性,阳性率为5.4％;禽口腔拭样中15份呈阳性,阳性率为10.6％;鱼和犬样品皆为阴性.进一步对阳性株进行分型鉴定,19株中9型7株,22型4株,1型、2型、16型及24型各1株,还有4株未知型号.对分离出来的19株菌株进行毒力岛GI4、GI8、GI12、毒力基因lin和rmp检测,结果为猪肉中分离出来的1株2型猪链球菌对GI8、GI12、lin阳性.分别用从猪肉中分离出的2型、鹧鸪中分离出的9型、鸽子中分离出的9型、鸡中分离出的1型、研究室保存的2型菌株9801对斑马鱼进行攻毒试验,结果各半数致死量（LD50）依次为4.27x 10^4CFU、2.72x 10^4CFU、5.18x10^3CFU、2.25x 10^4CFU、6.38x10^5CFU.

PCR technology was used to detect streptococcus suis from 317 samples of apparent healthy pork, poultry, fish anddog. The result showed that 4 samples of pork were positive, the positive rate was 5.4%, 15 samples of poultry were positive, thepositive rate was 10.6% ; while the samples of dog and fish were negative. The positive strains were further serotyped, there were 7strainsof type 9,4 strains of type 22, and 1 strain of typel, type 2, type 16 and type 24m repectively, and 4 unknown. One type 2strain isolated from pork contained the pathogenicity island of GI8, GIi2 and virulence genes of lin. Finally, the zebrafish werechallenged with the type 2 isolated from pork, type 9 isolated from partridge, type 9 isolated from pigeon, type 1 from chicken andtype 2 HA9801 kept by the laboratory. The LD50 were 4.27 x10^4CFU, 2.72x 10^4CFU, 5.18 x 10^3CFU, 2.25 x 10^4CFU and 6.38 x10^4CFU, respectively.