摘要
为了明确甘肃省某猪场发病猪病原及其相关生物特性,本试验采集临床发病猪心脏、肝脏、脾脏和关节液组织并进行病原分离和革兰染色,采用16S rRNA测序和血清分型鉴定菌株,并分析其毒力基因、药敏结果、生长曲线、致病性和免疫原性。结果显示,分离到1株猪链球菌3型,命名为LZS3。分离菌株LZS3携带epf、mrp和sly三种毒力基因;药敏试验结果显示,该菌株对左氧氟沙星、氟苯尼考和环丙沙星耐药,对阿莫西林和头孢噻吩敏感;生长曲线显示,LZS3培养8 h达到生长高峰;在小鼠感染模型中,LZS3以2.5×10^(8) CFU/只剂量感染小鼠可致其全部死亡,显示强致病性;利用铝胶和GEL02佐剂制备的灭活疫苗对小鼠保护率达90%~100%。结果表明,感染分离菌株LZS3治疗首选阿莫西林,LZS3免疫原性优异,可作为候选疫苗株,为猪链球菌3型的防治提供科学支撑。
To identify the causative pathogen and investigate its biological characteristics in diseased pigs from a pig farm in Gansu Province,tissue samples including heart,liver,spleen,and joint fluid were collected for pathogen isolation and Gram staining.The isolate was identified through 16S rRNA sequencing and serotyping,followed by analysis of virulence genes,antibiotic susceptibility,growth kinetics,pathogenicity,and immunogenicity.A single isolate of Streptococcus suis serotype 3 was successfully obtained and designated LZS3.Molecular analysis revealed that strain LZS3 harbors three major virulence genes:epf,mrp,and sly.Antibiotic susceptibility testing showed that the strain is resistant to levofloxacin,florfenicol,and ciprofloxacin,but sensitive to amoxicillin and cephalothin.Growth curve analysis showed that LZS3 reaches its growth peak at 8 hours.In a mouse infection model,inoculation with 2.5×10^(8)CFU/mouse LZS3 resulted in 100%mortality,demonstrating strong pathogenicity.Inactivated vaccines formulated with alum adjuvant or GEL02 adjuvant provided 90%-100%protection in mice,indicating excellent immunogenicity.In conclusion,amoxicillin is the preferred therapeutic agent for LZS3 infections.The strain exhibits strong immunogenic potential,supporting its use as a candidate vaccine strain,and provides a scientific support for the prevention and control of S.suis serotype 3.
作者
张阳
王胜华
赵文昌
ZHANG Yang;WANG Shenghua;ZHAO Wenchang(Jiuquan Vocational and Technical College,Jiuquan 735000,China;Chinese Center for Animal Disease Control and Prevention,Beijing 102618,China;Suzhou District Ren'ai Animal Hospital,Jiuquan 735000,China)
出处
《中国兽医杂志》
北大核心
2025年第10期58-63,共6页
Chinese Journal of Veterinary Medicine
基金
国家重点研发计划(2023YFD1800504)。
关键词
猪链球菌
分离鉴定
毒力基因
耐药
致病性
免疫原性
Streptococcus suis
isolation and identification
virulence gene
drug resistance
pathogenicity
immunogenicity
