目的 分析2023年1月至2024年1月湖北地区鸡滑液囊支原体的遗传特性及致病性，为湖北省鸡滑液囊支原体防控提供理论依据。 方法 将PCR鉴定阳性的病料通过液体培养基分菌，对分离纯化菌株的vlhA基因序列进行测序，用MEGA11软件分析构建进化树，并通过鸡胚感染试验及45日龄SPF鸡感染试验验证致病性。 结果 发现3株鸡滑液囊支原体与近年来国内的流行株亲缘关系最近，其中HB分离株的鸡胚感染试验显示该菌株具有较强的鸡胚致死性；动物毒力感染试验结果表明，不同剂量的菌液感染45日龄鸡，连续观察14 d，感染剂量为2×10⁶ CCU/只时，90%的鸡出现临床症状，且爪垫、趾跗关节发病部位病原分离率达到96%，龙骨囊肿部位基本无法分离到病原。 结论 本研究建立了一株鸡滑液囊支原体分离菌株的体内感染模型并分析了其感染症状与致病性，为鸡滑液囊支原体疫苗的开发和免疫保护评价提供了基础。

Objectives The genetic characteristics and pathogenicity of Mycoplasma synoviae in chickens from January 2023 to January 2024 in Hubei Province were analyzed to provide a theoretical basis for the prevention and control of Mycoplasma synoviae in chickens in Hubei Province. Methods Liquid culture medium was used to isolate strains from PCR positive samples. The vlhA gene of the isolated and purified strains was sequenced. A phylogenetic tree was constructed with the MEGA11 software. The pathogenicity was verified through chicken embryo infection test and 45-day-old SPF chicken infection test. Results Three strains of Mycoplasma synoviae were found to be most closely related to the epidemic strains in China in recent years. Among them, the chicken embryo infection test of the HB isolated strain showed that the HB isolated strain had strong lethality to chicken embryos. The results of the animal virulence infection test showed that when 45-day-old chickens were infected with different doses of bacterial solution and continuously observed for 14 days, 90% of the chickens developed clinical symptoms when the infection dose was 2×10⁶ CCU/animal. The rate of pathogen isolated from the affected parts of the claw pads and tarsometatarsal joints reached 96%, while it was almost impossible to isolate the pathogen from the affected parts of the keel bone cysts. Conclusions An in vivo infection model for a strain of Mycoplasma synoviae isolated from chickens was established. The infection symptoms and pathogenicity of the strain isolated were analyzed. It will provide a foundation for the development of vaccines against Mycoplasma synoviae and the evaluation of immune protection.