一株分离自流浪猫的猪链球菌9型的分子生物学鉴定

发布时间：2018-06-03 05:12

本文选题：猪链球菌 + 血清型型　；参考：《微生物学报》2016年02期

【摘要】：【目的】猪链球菌是一种能感染人和猪的人畜共患病病原,并且还可零星感染多种哺乳动物。本试验旨在调查流浪猫携带猪链球菌的情况。【方法】在流浪猫身上分离猪链球菌,经血清凝集实验和PCR检测,鉴定其血清型;经多序列位点分型分析,鉴定其ST型;将所分离的细菌与Gen Bank上已公布的猪链球菌构建16S rRNA的系统发育树,分析该菌株与其他猪链球菌的亲缘关系;药敏纸片法分析其耐药性;小鼠攻毒试验分析其毒力。【结果】本试验在流浪猫身上分离到一株猪链球菌,命名为m70,其血清型为9型。多序列位点分型显示,m70株属于一个新的ST型。与Gen Bank上已公布的猪链球菌16S rRNA进行系统发育树分析,结果显示m70属于一个单独的分支。m70与临床菌株的耐药情况相似,对四环素耐药,对红霉素中介耐药,对氨苄西林敏感。小鼠攻毒试验显示,感染10~8 CFU剂量m70的小鼠,死亡率达到60% 80%(3/5 4/5),3次攻毒试验的平均LD_(50)为5.1×10~7 CFU;而本实验室保存的猪链球菌强毒株HA9801感染小鼠的平均LD_(50)为3.9×10~7 CFU,两者之间没有显著差异(P0.05)。【结论】从流浪猫身上分离得到的猪链球菌m70属于优势血清型,且毒力较强,提示一些流行血清型的猪链球菌强毒株具有从流浪猫传染人的潜在风险。
[Abstract]:Objective: Streptococcus suis is a zoonotic pathogen that can infect human and pig, and it can infect a variety of mammals sporadically. The purpose of this study was to investigate the situation of streptococcus suis carried by stray cats. [methods] Streptococcus suis was isolated from stray cats, the serotype of streptococcus suis was identified by serum agglutination test and PCR detection, and its St type was identified by multilocus typing analysis. The phylogenetic tree of 16s rRNA was constructed between the isolated bacteria and Streptococcus suis published on Gen Bank, and the phylogenetic relationship between the strain and other Streptococcus suis was analyzed. [results] A strain of Streptococcus suis was isolated from stray cats, named as m70, and its serotype was serotype 9. Multiple locus typing showed that M70 belonged to a new St type. Phylogenetic tree analysis was performed with 16s rRNA of Streptococcus suis published on Gen Bank. The results showed that M70 belongs to a single branch. M70 is similar to clinical strains in drug resistance. It is resistant to tetracycline, erythromycin and ampicillin. Mice infected with 10 ~ 8 CFU dose of m70 showed that mice were infected with a dose of m70. The mortality rate was 60%. The average LDH50 for three times attack test was 5.1 脳 10 ~ 7 CFU, and the average LDX 50 for mice infected with HA9801 was 3.9 脳 10 ~ 7 CFU. [conclusion] there was no significant difference between the two groups. [conclusion] the average LDX 50 was 3.9 脳 10 ~ 7 CFU in mice infected with Streptococcus suis virulent strain. [conclusion] there is no significant difference between them. The obtained Streptococcus suis m70 belongs to the dominant serotype. The virulence of Streptococcus suis is strong, suggesting that some serotypes of Streptococcus suis have the potential risk of transmission from stray cats.
【作者单位】：南京农业大学世界动物卫生组织猪链球菌病参考实验室农业部动物细菌学重点实验室;广西壮族自治区动物疫病预防控制中心;
【基金】：国家自然科学基金(31402213) 江苏省自然科学基金(BK20140686) 中央高校基本科研业务费专项资金资助(KJQN201525)~~
【分类号】：S852.611

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