宁夏地区犊牛腹泻性大肠杆菌的分型鉴定及其主要毒力基因检测

发布时间：2018-04-22 12:43

本文选题：犊牛 + 腹泻　；参考：《宁夏大学》2016年硕士论文

【摘要】：为有效应对宁夏地区犊牛腹泻性疾病,研究宁夏地区犊牛腹泻性大肠杆菌优势血清型的分布与主要毒力基因。本课题于2015年3月至2015年12月间采集和接检宁夏区内因腹泻致死的犊牛组织样32头份,包括心、肝、脾、肺、肾和肠淋巴结共118份组织样；腹泻犊牛粪样86头份,共计204份样品,涉及118头腹泻犊牛。经微生物培养法、生化鉴定法和16S rDNA鉴定法,共计分离得到114株大肠杆菌,其中来自于组织样的有52株,来自于粪样的有62株。1、共选择34种大肠杆菌O抗原标准血清进行分型鉴定,结果显示：114株大肠杆菌所含血清型有O26、O138、O126、O51、O92、O107、O68、O86、O35、O13、O55、O8、 O142、O91、O137、 O144、O153、O18、O20、O101、O158、O22、O93、O148、O117、O109、09、O15、 O53共计29种血清型86株定型株,总检出率为75.43%；另O10、O112、O7、O128、O43五种血清型未能检出。依比例确定优势血清型为026(6/114)、 O126(5/114)、O18(9/114)、O35(4/114)、O158(8/114)、O101(6/114)、 O107(5/114)、09(5/114)共计48株,占参与分型菌株的42.11%,占定型菌株的55.81%；其中源于组织样的定型株有37株,来源于粪样的定型株有49株,另有28株未鉴定出血清型。2、针对48株优势定型株分别进行fimh、afa、eae、ehly、ipah和f41六种毒力基因检测。检测结果显示：含fimh基因的菌株达32株,占参与分析株比例的66.67%；含afa毒力基因的菌株有8株,占参与分析株比例的16.67%；含eae毒力基因的菌株有5株,占参与分析株比例的10.41%；同时存在fimh与afa基因的菌株有2株；其他3种毒力基因均未检测到。3、对部分菌株毒力基因的PCR产物测序后结果显示：所测eae及afa的基因序列与GenBank公开的对应基因核苷酸序列一致性达98%-100%。
[Abstract]:In order to effectively deal with diarrhea disease of calves in Ningxia area, the distribution and main virulence genes of predominant serotype of diarrhea Escherichia coli in calves in Ningxia area were studied. From March 2015 to December 2015, 32 samples of tissue samples were collected from calves killed by diarrhea in Ningxia district, including 118 tissues of heart, liver, spleen, lung, kidney and intestinal lymph nodes, and 86 samples of feces from diarrhea calves. A total of 204 samples involving 118 diarrhea calves. A total of 114 strains of Escherichia coli were isolated by microbial culture, biochemical identification and 16s rDNA identification, among which 52 were from tissue samples. The total detection rate was 75.43 and the other five serotypes, O10, O112O7O128O43, could not be detected. In proportion, the dominant serotypes were 026 / 6 / 114, O1266 / 5 / 114 / O18 / 9 / 11 / 4 / O35 / 4 / 4 / 8 / 8 / 114 / 10 / 6 / 114, O107 / 5 / 5 / 11409 / 5114) a total of 48 strains, accounting for 42.1111% of the strains participating in the typing and 55.81% of the stereotyped strains; among them, 37 were from tissue type and 49 were from fecal samples. Another 28 strains were not identified as serotypes. 48 dominant genotypes were tested for six virulence genes, fimhaaeeaeeaeeae ehlyipah and f41, respectively. The results showed that there were 32 strains with fimh gene, 8 strains with afa virulence gene and 5 strains with eae virulence gene. 10.41% of the strains involved in the analysis and 2 strains with fimh and afa genes. None of the other three virulence genes were detected. The PCR products of some virulence genes were sequenced. The results showed that the sequence of eae and afa was consistent with the nucleotide sequence of the corresponding gene published by GenBank.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S852.61

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