副猪嗜血杆菌对小鼠的致病性探究及感染模型的建立

Study on the Pathogenicity of Haemophilus parasuis to Mice and Establishment of Infection Model

为研究副猪嗜血杆菌(Haemophilus parasuis,HPS)对昆明系(KM)小鼠的致病性,同时探索建立HPS的KM小鼠感染模型,应用血清4型(SD-05、ZC-7、ND-21)、5型(BD-1、HB-08、PZ-26)菌株对KM小鼠进行毒力测定,然后以2种血清型最适菌株的最适剂量,腹腔注射KM小鼠开展攻毒试验,观察临床症状及剖检变化,并对死亡小鼠进行细菌分离以及PCR鉴定。结果显示:血清4型SD-05株、血清5型HB-08株毒力较强,对KM小鼠最适接种剂量分别为1.2×10^(9)及1.175×10^(9) CFU;攻毒后小鼠出现颤抖、萎靡厌食等临床症状,剖检可见肺脏出血、胸腔积液等病理变化,并在小鼠组织器官中成功分离出HPS菌株。结果表明,HPS血清4型、5型菌株对KM小鼠存在较强致病性,且初步认定KM小鼠可作为HPS感染动物模型。本研究为HPS致病性研究及小鼠感染模型建立奠定了应用基础。

In order to study the pathogenicity of Haemophilus parasuis(HPS)to Kunming(KM)mice,and establish an HPS infection model,the HPS virulence to KM mice was determined by the strains of serum serotype 4(SD-05,ZC-7 and ND-21)and serotype 5(BD-1,HB-08 and PZ-26),followed by challenge test through intraperitoneal injection in KM mice at an optimal dose of prime strains of two serum serotypes,to observe clinical symptoms and pathological changes,then the bacteria were isolated from dead mice and confirmed by PCR.The results showed that the serotype 4 SD-05 strain and serotype 5 HB-08 strain were more virulent,and their optimal inoculation doses were 1.2×10^(9) CFU and 1.175×10^(9) CFU respectively;clinical symptoms such as tremor,malaise and anorexia were observed in the challenged mice,and pathological changes such as lung hemorrhage and pleural effusion were seen under autopsy,HPS strain was isolated from the tissues and organs of the mice.In conclusion,HPS serotypes 4 and 5 were with strong pathogenicity to KM mice,and it was determined that KM mice could be used as a model of animals infected with HPS.In the paper,an application basis was provided for the study on HPS pathogenicity and establishment of the model of mouse infection.