摘要
为了了解大肠杆菌的致病性及携带毒力基因情况,试验对贵州贵阳清镇某养殖场患病麻黄鸡的心脏、肝脏、脾脏、肾脏及眶下窝组织采用细菌分离、生化鉴定、16S rDNA同源性分析等方法进行大肠杆菌的鉴定,对分离的病原菌进行药敏试验、毒力基因检测和致病性试验。结果表明:从病鸡心脏、肝脏、肾脏、脾脏及眶下窝组织分离到形态均一、圆形、边缘整齐、表面光滑的半透明菌落,为革兰氏阴性杆菌,将该分离菌命名为GZGY201912。分离菌GZGY201912能发酵葡萄糖、棉籽糖、木糖,鸟氨酸、赖氨酸和氨基酸对照试验均为阳性,硫化氢试验为阴性。分离菌GZGY201912 16S rDNA基因序列与大肠杆菌同源性最高,为100%,同时系统进化树显示,其与大肠杆菌聚为一支。分离菌GZGY201912仅对氨基糖苷类的阿米卡星敏感,对红霉素、卡那霉素表现中介,对羧苄西林、苯唑西林、氨芐西林等其余21种抗生素耐药。GZGY201912含有fimC、fimH、kpsⅡ、iss 4种毒力基因。分离菌GZGY201912浓度为3.3×108 cfu/mL时就能引起雏鸡致病,并能引起雏鸡出现纤维素性心包炎、嗉囊和肠管充气、腺胃肿大等症状。说明本研究成功分离到1株致病性大肠杆菌,且其携带4种毒力基因。
In order to understand the pathogenicity and carrying virulence genes of Escherichia coli(E. coli),E. coli was identified from the heart, liver, spleen, kidney and suborbital tissue of the diseased ephedra chicken in qingzhen, Guiyang, Guizhou by bacterial isolation, biochemical identification, and homology analysis of 16 S rDNA. Drug senstivity test, virulence gene detection and pathogenicity test were carried out with isolated pathogens.The results showed that from the heart, liver, kidney, spleen and suborbital tissue of the sick chickens, the isolated colonies were uniformly shaped, round, with neat edges, smooth on the surface, and translucent, which were Gram negative bacilli, named GZGY201912. The GZGY201912 strain can ferment glucose, raffinose, and xylose. The control tests of ornithine, lysine and amino acids were all positive, and the hydrogen sulfide test was negative. 16 S rDNA gene sequence of the isolate GZGY201912 had the highest homology with E. coli, which was 100%. Meanwhile, phylogenetic tree showed that it was clustered with E. coli. The GZGY201912 strain was only sensitive to amikacin which is an aminoglycoside, intermediate to erythromycin and kanamycin, and was resistant to the remaining 21 antibiotics such as carbenicillin, benzoxicillin and ampicillin. The GZGY201912 strain contained four virulence genes, such as fimC,fimH,kpsⅡ,and iss. The GZGY201912 strain concentration of 3.3×108 cfu/mL could cause disease in chickens, and could cause fibrinous pericarditis, inflation of crops and intestinal tubes, and enlarged glandular stomach in chickens. The results suggested that a pathogenic E. coli strain was successfully isolated in this study, and it carried 4 virulence genes.
作者
陈广
温贵兰
张喜懿
张小波
文明
程振涛
龚新勇
CHEN Guang;WEN Guilan;ZHANG Xiyi;ZHANG Xiaobo;WEN Ming;CHENG Zhentao;GONG Xinyong(College of Animal Science,Guizhou University,Guiyang 550025,China;Guizhou Provincial Key Laboratory of Animal Diseases and Veterinary Public Health,Guiyang 550025,China;College of Big Data,Guizhou University,Guiyang 550025,China)
出处
《黑龙江畜牧兽医》
CAS
北大核心
2021年第4期69-74,156,共7页
Heilongjiang Animal Science And veterinary Medicine
基金
2019年度贵州省农业科技支撑计划项目(黔科合支撑[2019]2286号)
贵州省高层次创新型人才培养项目(黔财教[2017]号)
贵州省科技平台及人才团队计划项目(黔科合平台人才[2018]5253)
贵州省研究生教育创新计划项目(GZZ2017002)
贵州大学博士基金项目(贵大人基合字[2013]12号)。
关键词
大肠杆菌
生化鉴定
药敏试验
致病性
临床症状
毒力基因
Escherichia coli
biochemical identification
drug sensitivity test
pathogenicity
clinical symptoms
virulence gene
