兔巴氏杆菌的分离与鉴定

Isolation and Identification of Rabbit Pasteurella

兔巴氏杆菌(Pasteurella)病又称为兔出血性败血症,由多杀性巴氏杆菌引起的一种急性传染病。近期,福建省某兔场大量母兔死亡,笔者对病兔进行剖检和病理组织学观察,还进行了实验室分子生物学检测和药敏试验。剖检发现病兔主要为肾脏有出血和白色病死灶,肺脏肿胀、出血、淤血,淋巴结出血等。病理组织学变化主要表现为病兔肺脏呈间质性肺炎,局部充血、出血;淋巴结则表现为生发中心增多;肾脏肾小管上皮细胞变性坏死,有的部分可见化脓性肾炎。细菌的分离鉴定结果表明,该病原体为革兰阴性菌,在血琼脂平板上呈单菌落、透明露滴状;生化试验结果表明,枸橼酸、明胶、葡萄糖、阿拉伯糖阳性;分子生物学PCR鉴定结果表明,1450 kb左右有一条特异性条带,符合预期;PCR产物测序结果表明,该菌与巴氏杆菌1986076011株同源性最高达到98.24%;动物试验结果表明,接种的试验小鼠全部死亡。可见,所分离的细菌是兔巴氏杆菌。药敏试验结果表明,该细菌对氟苯尼考、先锋霉素V、头孢曲松敏感,对氨苄西林、苯唑西林、哌拉西林等药物不敏感。

Rabbit Pasteurella multocida infection is also known as rabbit hemorrhagic septicemia,which is causedby Pasteurella multocida,Infection of pasteurella multocida can cause a large number of rabbit death a short time.Recently,A large number of pregnant rabbits died in a rabbit farm in Fujian Province.We examined the pathologicalchanges of the rabbits.White lesions were found in kidney.Pneumonedema and pneumorrhagia were found in lung.Hyperemia was found in Lymphatic node.In order to further investigate the pathological changes,the lungs,lymphnodes,kidneys and other tissues of the infected rabbits were collected.After fixation,the dehydration and embed-ding,pathological tissue sections and H.E staining were carried out.The main histopathological changes were inter-stitial pneumonia,congestion and hemorrhage in the lung of the infected rabbits.The number of germinal centerswas increased in lymph nodes.In the kidney,the epithelial cells of the renal tubules were degenerated and necrotic,and some of them have purulent nephritis.Then we separated and identified a bacterium from the painstaking care.And the molecular detection and drug sensitivity test were carried out.The results of bacterial isolation and identifi-cation showed that it was a single colony and transparent drop in the blood agar medium,and this pathogen wasgram-negative.The results of biochemical tests showed that citrate,gelatin,glucosereaction and arabinose reactionwere positive.Identification of PCR showed that there was a band around 1450 kb.The sequencing results of thePCR production indicated that the highest homology with strain 1986076011 was to 98.24%.And the infection re-sults showed that all mice-inoculated with Pasteurella multocida died.Visible,the isolated bacteria was rabbit Pas-teurella multocida.The drug sensitivity test showed that the bacterium was most sensitive to chloramphenicol,pio-neer mycin V,ceftriaxone,but it is not sensitive to ampicillin,oxacillin and piperacillin.