猪链球菌2型福建株的分离鉴定

从临床表现为败血症的濒死病猪肝脏、肺脏、淋巴结中分离到一株链球菌,进行形态学、生化特性、小白鼠感染试验及PCR鉴定和CPS2 J序列测定.结果表明:该分离菌的形态、培养和生化特性基本符合链球菌的特点;人工感染试验显示,小白鼠腹腔接种0.2 mL分离菌培养物不发病,但接种1 mL能在48 h内致小白鼠死亡,并能从脏器中分离到接种菌;分离菌的PCR扩增产物与猪链球菌2型阳性参考菌株JA070109大小一致、长度为675 bp的特异性条带,其PCR产物的核苷酸序列与GeneBank上公布的猪链球菌2型不同菌株的同源性高达98%-100%.可见,该分离菌为猪链球菌2型,并首次证实福建存在猪链球菌2型.

Isolation and identification of Streptococcus suis type 2 in Fujian

A bacterium strain was isolated from liver,lung,lymph node of dying swine with septicemia symptom.The isolates were identified by morphology,biochemistry,pathogenicity,PCR and CPS2J sequencing analysis.The results demonstrated that the morphology,culture and biochemical characteristics of the isolates were basically coincident with streptococcus character.Mice challenged with 0.2 mL of the bacterial culture did not cause visible symptoms,however,all mice died within 48 hours when challenged with 1mL of the bacterial culture by i.p.The microorganism same as the isolates was discovered in organs of dead mouse.The CPS2J gene PCR and sequencing analysis showed that the PCR product of the isolates was a 675 bp DNA fragment which was exactly same as the PCR product of Streptococcus suis type 2 positive reference strain(JA070109),and the sequence homology with S.suis type 2 CPS2J gene sequence from GeneBank was 98%-100%.All these results proved that the isolate was S.suis type 2.It was the first S.suis type 2 being isolated in Fujian Province.