猪链球菌江西分离株的生物学特性研究

发布时间：2018-04-25 23:20

本文选题：猪链球菌 + 分离　；参考：《江西农业大学》2017年硕士论文

【摘要】：猪链球菌(Streptococcus suis,SS)是猪链球菌病主要病原菌,能够引起猪的脑膜炎、败血症、心内膜炎、关节炎和肺炎,导致全球养猪业出现严重经济损失,也是一种重要的人畜共患病原菌,具有公共卫生学意义。本研究针对江西地区分离得到的猪链球菌的耐药性、毒力基因型分布及血清型进行检测分析,以期为江西地区猪链球菌病防治奠定基础。在2014年至2016年间,从江西省多个不同规模猪场,对疑似猪链球菌病的病猪进行病料采集,通过细菌的分离培养、特异性PCR鉴定及测序比对,共得到62株猪链球菌,其中在肺脏分离率最高。多数猪链球菌病呈现与其它病原混合感染,主要为PRRSV和PCV-2。运用PCR基因分型方法对62株猪链球菌的流行的1、2、7、9型进行鉴定。其中猪链球菌1型8株,猪链球菌2型22株,猪链球菌9型5株,分别占12.9%、35.5%、8.1%,未知血清型占43.5%,未检测到7型猪链球菌。表明江西省存在猪链球菌的多种血清型感染,其中猪链球菌2型为主要流行血清型。根据猪链球菌6种主要毒力基因(mrp、orf2、gdh、sly、fbps、epf),设计合成对应引物序列,对62株猪链球菌进行检测,检测结果为:gdh(62/100%),mrp(47/75.8%),epf(33/53.2%),fbps(36/58.1%),orf2(34/54.8%),sly(14/22.3%)。22株猪2型链球菌中各种毒力因子占比均高于平均水平,可分为10种基因型,gdh+mrp+epf+fbps+orf2+sly-和gdh+mrp+epf+fbps+orf2+sly+为主要基因型。选取16种临床常用抗菌药物,应用K-B纸片琼脂扩散法,对62株猪链球菌进行药物敏感性试验,结果显示,猪链球菌江西分离株多重耐药严重,多重耐药分离株数为59(95.16%)。对四环素、红霉素、强力霉素耐药最为严重,分别占96.78%、80.64%和80.64%;对头孢唑啉、头孢噻肟和阿莫西林敏感度较高,分别占85.49%、87.1%和82.26%。表明猪链球菌在一定程度上对常用药物产生了耐药性。
[Abstract]:Streptococcus suis (Streptococcus suis, SS), the main pathogen of Streptococcus suis disease, can cause meningitis, septicemia, endocarditis, arthritis and pneumonia in pigs, causing serious economic losses in the global pig raising industry. It is also an important zoonosis, which has the significance of public hygiene. This study was isolated in Jiangxi area. The drug resistance, the distribution of virulence genotype and the serotype of Streptococcus suis were detected and analyzed in order to lay the foundation for the prevention and control of Streptococcus suis disease in Jiangxi. From 2014 to 2016, from various pig farms in Jiangxi Province, the diseases of pigs suspected to be Streptococcus suis were collected, the isolation and culture of bacteria, specific PCR identification and measurement were carried out. 62 strains of Streptococcus suis were obtained by sequence alignment, among which the lung separation rate was the highest. Most Streptococcus suis disease was mixed with other pathogens, mainly PRRSV and PCV-2. used PCR genotyping to identify the 62 strains of Streptococcus suis, including 8 strains of Streptococcus suis, 22 Streptococcus suis type 2, and 5 strains of Streptococcus suis 9, and 5 strains of Streptococcus suis. 12.9%, 35.5%, 8.1%, unknown serotypes accounted for 43.5%, and no Streptococcus suis type 7 was not detected. It showed that there were a variety of serotype infection of Streptococcus suis in Jiangxi Province, and Streptococcus suis 2 was the main serotype. According to the 6 main virulence genes of Streptococcus suis (MRP, ORF2, GDH, sly, FBPS, EPF), the sequence of corresponding primers was designed and synthesized, and 62 pig chains were designed. The test results were as follows: GDH (62/100%), MRP (47/75.8%), EPF (33/53.2%), FBPS (36/58.1%), ORF2 (34/54.8%), sly (14/22.3%) type 2 streptococci were all higher than the average level, and could be divided into 10 genotypes. 16 species were selected. 62 strains of Streptococcus suis were tested by K-B paper agar diffusion method. The results showed that the multidrug resistance of Streptococcus suis Jiangxi isolates was serious and the number of multidrug resistant isolates was 59 (95.16%). The most serious resistance to tetracycline, erythromycin, and doxycycline was 96.78%, 80.64% and 80.64%, respectively. The sensitivity of cephalosporin, cefotaxime and amoxicillin was 85.49%, 87.1% and 82.26%. respectively, indicating that Streptococcus suis was resistant to commonly used drugs.

【学位授予单位】：江西农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S852.611

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