China Animal Husbandry and Veterinary Medicine ›› 2024, Vol. 51 ›› Issue (7): 3128-3141.doi: 10.16431/j.cnki.1671-7236.2024.07.037

• Basic Veterinary Medicine • Previous Articles    

Isolation,Identification and Pathogen Characteristics Evaluation of a Strain of Pasteurella multocida D:L3:L5 from Cattle

ZHAO Yiduo1,2,3, ZHANG Kang2,3, WANG Lei2,3, LU Xiaorong2,3, ZHANG Jingyan2,3, CHENG Jia1, GUO Zhiting2,3, XU Guowei2,3, HUANG Liping2,3, NIU Yuhui2,3, MA Ting2,3, FENG Xiaowei2,3, EGIDE2,3, LIU Mingchao1, LI Jianxi2,3   

  1. 1. College of Veterinary Medicine, Hebei Agricultural University, Baoding 071000, China;
    2. Lanzhou Institute of Animal Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China;
    3. Engineering and Technology Research Center of Traditional Chinese Veterinary Medicine of Gansu Province, Lanzhou 730050, China
  • Received:2023-11-01 Published:2024-07-03

Abstract: 【Objective】 The experiment was aimed to explore the distribution of capsule serotypes,drug resistance and virulence genes of Pasteurella multocida from a large-scale dairy farm in Xining city,Qinghai province,in order to provide reference for the treatment and prevention of respiratory diseases caused by Pasteurella multocida in cattle.【Method】 Bacteria were isolated from the lung sample of a dead cattle.And then,through the methods of colony observation,dyeing microscopy,biochemical identification,specific primer amplification,16S rRNA clone sequencing analysis,phylogenetic tree construction,capsular serum and lipopolysaccharide type,virulence gene detection,pathogenicity test and drug sensitivity test,the isolated Pasteurella multocida was identified and its pathogen characteristics were evaluated.【Result】 The colonies isolated from the lung samples were dewdrop-like with a slight depression in the gray middle,and no hemolysis ring appeared.Gram staining showed coccidia pink,Wright’s staining showed blue coccidia with dense staining at both ends.Biochemical identification showed that the results of D-glucose,D-mannitol,D-mannose,tyrosine arylaminase,phosphatase,COURMARATE and ELLMAN reaction were positive.16S rRNA sequencing results showed that the strain was more than 95% similar to a variety of Pasteurella multocida,and the isolated strain was identified as Pasteurella multocida and named XN222.The results of capsule serum typing and lipopolysaccharide type showed that XN222 was classified as type D,and its lipopolysaccharide types were L3 and L5.The results of virulence gene amplification showed that XN222 carried 19 virulence genes,including ptfA,fimA,hsf-2, sodA, tbpA, sodC,and so on.The results of pathogenicity test in mice showed that injection of 0.2 mL 1.5×108 CFU/mL bacterial solution resulted in 100% (10/10) death of mice,indicating that the isolated strain XN222 had strong pathogenicity. The results of drug sensitivity test showed that XN222 was sensitive to 15 kinds of antimicrobial agents,such as ceftiofur,levofloxacin,enrofloxacin,marbofloxacin,tetracycline and penicillin,and was moderately sensitive to tylosin.【Conclusion】 In this study,a highly pathogenic Pasteurella multocida type D strain was isolated.The discovery of this strain enriched the domestic bovine subtype of Pasteurella multocida,and provided biological materials for the prevention and control of bovine respiratory diseases caused by Pasteurella multocida,etiological investigation and development of Pasteurella multocida multivalent vaccine.

Key words: Pasteurella multocida type D; isolation and identification; pathogen characteristics

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