摘要
为查明贵州省某猪场中引起仔猪呼吸道疾病的病原菌,深入了解该病原的生物学特性,无菌采集病死猪肺组织,于含血清的胰蛋白胨大豆琼脂培养基划线培养分离菌株,采用形态学观察、生化试验、16S rRNA基因测序、PCR-限制性片段长度多态性(PCR-RFLP)等方法对分离到的疑似菌株进行鉴定,并进行毒力基因检测和药物敏感性测定,最后通过小鼠模型测定了其致病性。结果:分离菌株为猪链球菌1型,命名为S240051;对庆大霉素、卡那霉素、新霉素、链霉素、多西环素、四环素、万古霉素、磺胺异噁肟8种抗生素耐药;对青霉素、阿莫西林、头孢噻肟、氨苄西林、环丙沙星、恩诺沙星、左氧氟沙星、泰妙菌素、克林霉素、利福平11种抗生素敏感;携带sly(链球菌溶血素S)、epf(胞外蛋白酶因子)、mrp(黏附性纤毛蛋白)、orf2(开放阅读框2)、fbps(纤维蛋白原结合蛋白)、gapdh(甘油醛-3-磷酸脱氢酶)、srt A(分选酶A)、ccp A(分解代谢物控制蛋白A)等毒力基因;该菌感染浓度为3.96×10~9CFU/只时,感染小鼠100%死亡,且死亡小鼠肺脏、肝脏和脾脏组织病理切片可见明显病变。以上研究丰富了猪链球菌病病原生物学资料,为猪链球菌1型耐药机制和致病机理研究奠定了基础。
To investigate the etiology of respiratory diseases in piglets from a swine farm in Guizhou Province and characterize the biological features of the causative pathogen,samples of lung tissues from dead pigs were aseptically collected for bacterial isolation.Suspected strains were purified via streaking on serum-enriched tryptone soybean agar(TSA)medium.The isolates were then systematically identified through morphological analysis,biochemical profiling,16S rRNA gene sequencing,and PCR-RFLP.Further characterization included virulence gene detection and antimicrobial susceptibility testing.Finally,pathogenicity was evaluated using a murine infection model.The results were that the isolated strain was designated as Streptococcus suis serotype 1(SS1)strain S240051,it was resistant to 8 antibiotics,including gentamicin,kanamycin,neomycin,streptomycin,doxycycline,tetracycline,vancomycin and sulfamethoxazole,and it was sensitive to 11 antibiotics including penicillin,amoxicillin,cefotaxime,ampicillin,ciprofloxacin,enrofloxacin,levofloxacin,tiamulin,clindamycin and rifampin.Virulence genotyping confirmed the presence of sly,epf,mrp,orf2,fbps,gapdh,strA,ccpA genes.When the infection concentration of the bacterium was 3.96x 10 CFU/mouse,100%of the mice died.Histopathological analysis revealed significant lesions in the lung,liver,and spleen tissues of the infected mice.This study enriched the pathogenic and phenotypic data on Streptococcus suis and presented foundational insights into the drug resistance mechanisms and pathogenicity of Streptococcus suis Serotype 1.
作者
陈家丽
周思旋
林如涛
史开志
吴昊
陈席敏
陈玉霞
王冬丁
朱祉聿
吴屿彤
CHEN Jiali;ZHOU Sixuan;LIN Rutao;SHI Kaizhi;WU Hao;CHEN Ximin;CHEN Yuxia;WANG Dongdin;ZHU Zhiyu;WU Yutong(College of Animal Sciences,Guizhou University,Guiyang 550025,China;Institute of Animal Husbandry and Veterinary Medicine,Guizhou Academy of Agricultural Sciences,Guiyang 550005,China)
出处
《畜牧与兽医》
北大核心
2026年第2期71-79,共9页
Animal Husbandry & Veterinary Medicine
基金
贵州省科技计划项目(黔科合支撑[2022]重点032,黔科合支撑[2022]一般088,黔农科科技创新[2023]07,黔农科院科技创新[2022] 01,黔科合成果[2022]一般007号)。
关键词
猪链球菌1型
毒力基因
致病性
耐药性
分离鉴定
Streptococcus suis serotype 1
virulence genes
pathogenicity
drug resistance
isolation and identification
