China Animal Husbandry and Veterinary Medicine ›› 2023, Vol. 50 ›› Issue (1): 368-376.doi: 10.16431/j.cnki.1671-7236.2023.01.037

• Basic Veterinary Medicine • Previous Articles     Next Articles

Isolation, Identification and Antimicrobial Susceptibility of Mycoplasma gallisepticum from Different Areas

WEI Jin, WANG Jia, ZHAO Haoran, LIU Bo, LIU Yuanjie, YAO Wensheng, LIU Yan, MA Xin   

  1. China Institute of Veterinary Drug Control, Beijing 100081, China
  • Received:2022-09-14 Online:2023-01-05 Published:2023-01-04

Abstract: 【Objective】 The aim of this experiment was to investigate the prevalence and drug resistance of Mycoplasma gallisepticum (MG) in different areas of China, so as to provide a scientific basis for the surveillance, prevention and control of MG disease.【Method】 The prevalent strains were isolated and purified from the 43 infected air sacs from suspected MG infected chickens in poultry farms of Guangdong, Fujian and Anhui provinces.The isolates were identified by culture characteristics test, biochemical characteristics test, Giemsa staining, serological methods and then PCR sequencing analysis, pathogenicity and sensitivity to common antibiotics were tested.【Result】 3 isolates were obtained successfully, and could change the broth medium from red to yellow.They showed typical "fried egg"-like colony in the solid medium and could ferment glucose, not hydrolyze arginine, and not decompose urea, which were consistent with the culture characteristics of MG.Results of Giemsa staining and serological specific identification further confirmed the isolates to be MG. The sequence analysis of the mgc2 gene revealed that the 3 isolates were more closely related to the typical virulent strains.Animal challenge tests showed that the clinical symptoms of the 3 isolates were consistent with those of MG infection, and the incidence was 70%-90%, the 3 isolates had high pathogenicity.The results of antimicrobial susceptibility test showed that the 3 isolates were resistant to enrofloxacin, temicoxin, oxytetracycline and flufenicol, and were sensitive to tylvalosin and warnimilin.The sensitivity of the 3 isolates to spectinomycin, aureomycin, tyloxacin and tiamulin was different in different regions.The Fujian strain showed obvious resistance to spectinomycin, the Anhui strain showed resistance to tiamulin, and the Guangdong strain was sensitive to spectinomycin, aureomycin and tiamulin.【Conclusion】 3 MG isolates with high pathogenicity were isolated, and they were drug-resistant, their sensitivities to drugs were regional.In the future, it was still necessary to strengthen the drug sensitivity monitoring of MG in various regions to reduce the emergence and spread of drug resistance.

Key words: Mycoplasma gallisepticum; isolation and identification; drug sensitive test

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