China Animal Husbandry and Veterinary Medicine ›› 2025, Vol. 52 ›› Issue (3): 1405-1415.doi: 10.16431/j.cnki.1671-7236.2025.03.041

• Basic Veterinary Medicine • Previous Articles    

Isolation,Identification and Drug Resistance Analysis of a Strain of Corynebacterium pseudotuberculosis from Goats

LIU Zewu1, FAN Yueyuan1, YUANJiarui1, GESANG Zhuoga2, BAN Dan2, BAI Weibing1, CHAJinlong3, SILANG Yuzhen2, FU Guowen1   

  1. 1. Yunnan Agricultural University, Kunming 650000, China;
    2. Institute of Animal Husbandry and Veterinary, Tibet Academy of Agriculture and Animal Husbandry Sciences, Lhasa 850000, China;
    3. Yunnan Agricultural Vocational and Technical College, Kunming 650031, China
  • Received:2024-06-10 Published:2025-02-22

Abstract: 【Objective】 The purpose of this experiment was to identify the pathogen of goats suspected to be suffering from pseudotuberculosis in a farm in Yiliang,Yunnan province,and explore its drug resistance and pathogenicity,so as to provide theoretical basis for the diagnosis and treatment of the disease.【Method】 According to the clinical symptoms of the infected goats,the cause of the disease was preliminarily determined,the disease material was collected aseptically,and the pathogenic bacteria were isolated and purified to identify the morphological characteristics,culture characteristics and biochemical characteristics.The 16S rRNA gene sequences of the isolate was amplified by PCR and analyzed by sequencing.The drug resistance and pathogenicity of the isolate were investigated by drug susceptibility test,drug resistance gene test and pathogenicity test in mice.【Result】 The isolate grew well on the blood agar plate,the colonies were yellowish-white and opaque,and did not grow well in the common nutrient agar and the common nutrient broth.Gram staining microscopy showed that the bacteria were spheroidal or rod-shaped and Gram-positive bacteria.The results of biochemical identification showed that glucose and urea tests were positive,while lactose,maltose,mannitol,sucrose,Simon’s citrate,hydrogen sulfide,indigo matrix,nitrate reduction test,methyl red (MR) test and VP test were negative.16S rRNA sequence alignment results showed that,the 16S rRNA gene sequence similarity between the isolated and Corynebacterium pseudotuberculosis in NCBI database was more than 99%,and it was identified as Corynebacterium pseudotuberculosis.Drug sensitivity test results showed that,the isolate showed intermediation to streptomycin,gentamicin and neomycin,and resistance to amtronam,ceftazidime and polymyxins.The results of drug resistance gene detection showed that the isolate carried drug resistance genes Sul2,Sul3,blaTEM and blaCTX-M. The results of animal pathogenicity test showed that abdominal and subcutaneous inoculation with 4.4×108 CFU/mL isolated bacteria could cause death of mice,and the mortality rate was 100%.Subcutaneous abscess appeared 96 h after subcutaneous inoculation,and Corynebacterium pseudotuberculosis could be isolated from the pus.【Conclusion】 In this experiment,a strain of Corynebacterium pseudotuberculosis of goats origin was successfully isolated and identified,and the pathogen of the infected goats was identified.The strain was highly pathogenic to mice.The results provided reference for the diagnosis,epidemiological investigation and treatment of Corynebacterium pseudotuberculosis infection in goats.

Key words: goats; Corynebacterium pseudotuberculosis; isolation and identification; drug resistance

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