[背景] 化脓隐秘杆菌作为一种条件致病菌，常与蓝耳病病毒、猪圆环病病毒、巴氏杆菌等混合感染猪，引起各种非特异性化脓性感染，部分临床症状与副猪嗜血杆菌相似。本试验从江西某猪场一起因呼吸道症状急性死亡病猪的肺脏分离到一株具有β溶血特性、疑似化脓隐秘杆菌的细菌病原。[目的] 鉴定该病原的菌属种类、生物学特性及基因组特征，为该菌疾病的基础研究与临床防控奠定理论基础。[方法] 采用透射电镜、扫描电镜结合PCR鉴定等方法对菌属种类进行鉴定；通过动物实验、药敏试验，分析菌株的生物学特性；借助全基因组测序、生物信息学等技术发掘该菌的基因组特征。[结果] 形态观察、16S rRNA基因鉴定及系统发育分析证实，该分离菌株是化脓隐秘杆菌，命名为JX18；药敏试验表明，该菌株对克林霉素和林可霉素不敏感，对其余所选药物均敏感；动物实验结果显示，对小鼠腹腔攻毒后，小鼠腹部出现明显脓肿病灶，最高剂量组的小鼠全部死亡；全基因组测序结果表明，该菌株携带plo、nanH、nanP、fimA、fimC、fimE等重要毒力基因，并且与其他化脓隐秘杆菌菌株毒力基因的相似性较高；根据同源基因数据库（Cluster of Orthologous Groups，COG）预测，菌株JX18中参与碳水化合物代谢的基因占比最高；通过毒力基因数据库（virulence factor database，VFDB）、UniProtKB/Swiss-Prot等数据库预测，JX18菌株基因组中携带有多个组氨酸激酶、反应调节因子等与细菌双组分调控系统相关基因，以及多种与粘附、侵入及分泌系统相关的毒力基因。[结论] 在江西省分离鉴定出一株猪源强致病性化脓隐秘杆菌，丰富了猪源化脓隐秘杆菌病原信息，为进一步开展猪源化脓隐秘杆菌相关研究与防控奠定了理论依据。
[Background] As an opportunistic pathogen, Trueperella pyogenes is frequently associated with mixed infections with porcine reproductive and respiratory syndrome virus, porcine circovirus, or Pasteurella, which can cause various non-specific suppurative infections. Some clinical symptoms are similar to those of Haemophilus parasuis infection. In this study, a bacterial pathogen showing β-hemolysis was isolated from the lung of an infected pig that died of respiratory symptoms in Jiangxi Province. [Objective] To investigate the species, biological characteristics, and genomic characteristics of the isolated pathogen. Our study aimed for better understanding of the pathogenesis of bacterial infection. [Methods] The morphology of the isolated bacteria was characterized by transmission electron microscopy and scanning electron microscopy. The pathogenicity, biological characteristics, and genomic characteristics of the bacteria were confirmed through animal experiments, drug sensitivity test, whole genome sequencing and bioinformatics analysis, respectively. [Results] Through morphology observation, identification of 16S rRNA gene, and phylogenetic analysis, it was confirmed that the isolated pathogen was Trueperella pyogenes and named JX18. Results of the drug sensitivity test showed that JX18 was resistant to clindamycin and lincomycin, but sensitive to other selected drugs. The results of animal experiments showed that typical symptoms of suppurative infection appeared in the abdomen of mice after the challenge of T. pyogenes JX18. All mice challenged with the highest dose died. Results of the whole-genome sequencing showed that JX18 carries important virulence genes, including plo, nanH, nanP, fimA, fimC and fimE. Moreover, these virulence genes have high homology with that of other T. pyogenes strains. Results suggested that genes involved in the carbohydrate transport and metabolism have the highest proportion in the genome of JX18. According to the VFDB and UniProtKB/Swiss-Prot databases, JX18 carries multiple histidine-kinase genes, response regulator genes, genes of the bicomponent regulatory system, and virulence genes related to adhesion, invasion, and secretion. [Conclusion] In this study, a high pathogenic pathogen, T. pyogenes JX18, was isolated in Jiangxi province and had been identified. Our study may enrich the pathogenic information of T. pyogenes, and provide the foundation for exploring strategies for the prevention and control of T. pyogenes infection.