摘要
为确诊广东省江门市某规模化猪场保育仔猪发生脑膜炎死亡的病因,本研究通过临床解剖观察、细菌分离培养、革兰染色镜检、溶血性观察、生化鉴定、小鼠毒力试验和药敏试验、16S rRNA及M蛋白(SzP)基因序列分析进行鉴定。结果:从发病猪脑顶叶分离到1株致病菌,命名为SEZ20180618,分离菌在鲜血平板上生长出微隆起、圆滑湿润的小菌落,呈β溶血,革兰染色阳性、呈链状排列的球菌;16S rRNA基因序列分析显示,分离菌与马链球菌兽疫亚种处于同一分支,同源性在97%以上;SzP氨基酸序列与马链球菌兽疫亚种CT株、Cxy012株、SH00166株等参考菌株的相应序列同源性为100%。分离菌株SEZ20180618对BALB/c小鼠具有较强的毒力,对BALB/c小鼠的半数致死量为1.54×10^(6 )CFU;分离菌对阿莫西林、青霉素、庆大霉素等14种临床常用抗菌药物均敏感,对阿米卡星和复方新诺明2种药物中度敏感。
In order to determine the cause of death of piglets from meningitis in a large-scale pig farm in Jiangmen City, Guangdong Province, investigation was performed in this study using clinical anatomical observation, bacterial isolation and culture, gram staining microscopy, hemolytic observation, biochemical identification, mouse virulence test and drug sensitivity test, 16 S rRNA and M protein(SzP) gene sequence analysis. The results showed that a pathogenic bacterium, named SEZ20180618, was isolated from the parietal lobe of the infected porcine brain. The isolated bacterium grew into small, smooth and moist colonies with slight eminence, and showed β hemolysis. Gram-positive Streptococcus was observed by gram staining. The 16 S rRNA gene sequence analysis showed that the isolates and the Streptococcus equi subsp. zooepidemicus were of the same branch, and their homology was over 97%. The homology of the SzP amino acid sequence with CT, Cxy012, SH00166 and other reference strains of Streptococcus equi subsp. zooepidemicus was 100%. SEZ20180618 had strong pathogenicity to BALB/c mice, and its lethal dose to mice was 1.54×10^(6) CFU. This pathogen was sensitive to 14 commonly used antibiotics such as amoxicillin, penicillin and gentamicin, etc. and moderately sensitive to amikacin and cotrimoxazole.
作者
邓汝森
张海龙
颜广智
陈盛楠
顾万军
黄良宗
DENG Husen;ZHANG Hailong;YAN Guangzhi;CHEN Shengnan;GU Wangjun;HUANG Liangzong(College of Life Science and Engineering,Foshan Science and Technology University,Foshan 528000,China;Guangdong Findergene Technology Co.,Ltd,Foshan 528000,China)
出处
《畜牧与兽医》
北大核心
2021年第9期66-70,共5页
Animal Husbandry & Veterinary Medicine
基金
广东省现代农业产业技术体系生猪创新团队项目(2019KJ126)
广东君睿生物技术研究有限公司项目。
关键词
马链球菌兽疫亚种
分离鉴定
药敏试验
猪
Streptococcus equi subsp.zooepidemicus
isolation and identification
drug sensitivity test
swine
