鸡源多杀性巴氏杆菌的分离鉴定及生物学特性分析

Isolation,identification and biological characteristic analysis of Pasteurella multocida from chicken

为了对云南某鸡场发生鸡急性死亡的疑似禽霍乱病例进行病原确诊,无菌采集送检死鸡肝脏组织进行细菌分离培养、生化鉴定、细菌16S rRNA基因分析及荚膜分型鉴定,对分离菌株进行耐药性、致病性分析。结果,该分离菌为荚膜A型多杀性巴氏杆菌;药敏试验表明,分离菌对头孢氨苄、头孢他啶、阿莫西林、氨苄西林等8种药物敏感,对大观霉素、复方新诺明等6种药物中度敏感,对卡那霉素、链霉素、四环素等12种药物耐药;耐药基因检测显示,该分离株仅含有磺胺类sul2基因和四环素类tetB基因;动物试验表明,接种500 CFU的45日龄鸡在接种后7 d内全部死亡,接种12.5 CFU的小鼠在接种后48 h内全部死亡,死亡小鼠病理组织切片显示各器官均有不同程度的病变。上述结果表明,该分离株为荚膜A型多杀性巴氏杆菌强毒株,是该鸡场发生疫情的病原。本研究结果为我国鸡源多杀性巴氏杆菌的遗传特性研究提供了基础资料。

In order to determine the pathogen of suspected avian cholera in a chicken farm in Yunnan province,aseptic collection of dead chicken liver tissue for bacterial isolation and culture,biochemical identification,bacterial 16S rRNA gene and capsular type analysis,drug resistance and animal pathogenicity experiment was carried out.In result,the isolate was Pasteurella multocida capsular Serotype A.The susceptibility test showed that the isolate was sensitive to 8 kinds of drugs such as cefalexin,ceftazidime,amoxicillin and ampicillin,moderately sensitive to 6 kinds of drugs such as spectinomycin and sulfamethoxazole,and resistant to 12 kinds of drugs such as kanamycin,streptomycin and tetracycline.The detection of drug resistance gene showed that the isolate contained only sulfonamide sul2 gene and tetracycline tet B gene.animal pathogenicity experiment showed that all the 45-day-old chickens inoculated with 500 CFU died within 7 days,and all the mice inoculated with 12.5 CFU died within 48 hours.The pathological sections of the dead mice showed different degrees of pathological changes in all organs.In summary,the isolate is a virulent strain of P.multocida capsular Serotype A,which is the pathogen of the epidemic situation in this chicken farm.This experiment results can provide references for genetic characteristics study of chicken P.multocida isolates in China.