China Animal Husbandry and Veterinary Medicine ›› 2024, Vol. 51 ›› Issue (12): 5570-5576.doi: 10.16431/j.cnki.1671-7236.2024.12.043

• Basic Veterinary Medicine • Previous Articles     Next Articles

Isolation,Identification and Pathogenicity Analysis of a Strain of Pasteurella multocida A∶L3 from Yaks

ZHUO Ma   

  1. Institute of Animal Husbandry and Veterinary, Xizang Academy of Agriculture and Animal Husbandry Sciences, Lhasa 850000, China
  • Received:2024-03-19 Published:2024-12-02

Abstract: 【Objective】 The objective of this study was to explore the etiology of disease and death of yaks in a breeding farm in Ali area,Tibet,and analyze the biological characteristics of the pathogenic bacteria,so as to provide reference for effectively preventing and controlling the disease.【Method】 Tissues of dead yaks were collected aseptically,and laboratory diagnosis was carried out according to clinical symptoms,and pathogenic bacteria were isolated and cultured.The isolate was identified by morphological observation,biochemical identification,16S rRNA PCR amplification and sequencing,kmt gene identification,capsular serotyping and lipopolysaccharide typing.The drug sensitivity and pathogenicity of the isolate was investigated.【Result】 The isolate grew grayish white,transparent and dewdroplet colonies in 7% serum TSA medium.Gram staining showed strong Gram-negative brevibacterium at both ends.The results of biochemical tests showed that the isolate was positive in glucose,ornithine decarboxylase,oxidase,sorbitol and mannitol biochemical reaction tubes.The results of capsular serotyping and lipopolysaccharide typing showed that the isolate was Pasteurella multocida capsular type A,and its lipopolysaccharide type was L3.Drug susceptibility test showed that the isolate was sensitive to carbenicillin,ampicillin,cefazolin,gentamicin,nitrofurantoin,cefuroxime,amicana,minocycline and norfloxacin.The results of pathogenicity test showed that the mortality rate of mice was 100% (5/5) after injecting 0.2 mL 1×108 CFU/mL of the isolate bacterial solution,and the isolate had strong pathogenicity.【Conclusion】 In this study,a strain of serotype A lipopolysaccharide L3 Pasteurella multocida was successfully isolated and identified,which was sensitive to carbenicillin,ampicillin,cefazolin and other drugs,and was highly pathogenic.The results provided data reference for exploring the biological information and etiological characteristics of Pasteurella multocida from yaks.

Key words: Pasteurella multocida; yak; isolation and identification; pathogenicity

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