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为了调查青岛地区牛源产志贺毒素大肠杆菌(STEC)的流行情况和耐药情况,本试验对保存的780株牛源大肠杆菌进行PCR鉴定、血清分型以及药敏试验,经测序确认共检出27株STEC,随后对检出的STEC进行了30种血清型的鉴定,鉴定出14株共9种血清型,占定型菌株的51.9%,其中以O78、O2、O45血清型为主且O78占定型菌株的14.8%,为优势血清型。药敏试验结果显示,27株STEC对四环素、氨苄西林的耐药率分别为88.9%和81.5%;对氟苯尼考、磷霉素、恩诺沙星、萘啶酸、头孢噻呋、链霉素、甲氧苄啶-磺胺甲噁唑的耐药率介于11.1%~59.3%;对卡那霉素具有较高敏感性,耐药率仅为7.4%;所有受试菌株均对阿米卡星、环丙沙星和左氧氟沙星敏感。本试验结果对青岛地区牛源STEC的治疗提供理论依据。 相似文献
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《畜牧与兽医》2016,(8):18-21
为建立双抗体夹心ELISA法检测产志贺毒素大肠杆菌(STEC)Ⅰ型志贺毒素(Stx1),利用重组Ⅰ型志贺毒素A亚单位(Stx1A)免疫小鼠,制备单克隆抗体,从中筛选出非竞争性的2株单抗,构建双抗体夹心法ELISA检测方法,并对试验样品中的志贺毒素进行检测。结果显示:共获得4株针对Stx1A的单克隆抗体,分别为1H2-G7、2H1-C12、8E7-E6和2F6-F8。当8E7-E6作为包被抗体,而2F6-F8作为检测抗体时,其检测毒素的OD值最高。对样品中的Stx进行检测,表明该方法只有效识别Stx1,对Stx2不识别。结论:成功建立了用于检测Stx1的双抗体夹心ELISA法,为临床上快速诊断STEC感染奠定了基础。 相似文献
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产志贺毒素大肠杆菌(Shiga toxin-producing Escherichiacoli. STEC)是一种重要的人畜共患病病原菌,可以引起人类水样腹泻、岀血性肠炎等轻度肠不适,严重时导致溶血性尿毒综合征(Hemolytic uremic syndrome, HUS)、终末期肾病(End stage renal disease, ESRD)甚至死亡。有研究显示,每年全球范围内估计感染致病型STEC造成超过2800000例人类急性疾病,死亡230例[1].鉴于STEC对全球公共安全的重要影响,对其高效检测和鉴定至关重要. 相似文献
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产肠毒素大肠杆菌主要致病因子及其致病机理的研究进展 总被引:1,自引:0,他引:1
仔猪腹泻是畜牧业养殖的主要问题之一,每年在世界范围内造成极大的经济损失。肠毒素大肠杆菌(enterotoxigenicescherichia coli,ETEC)是引起仔猪腹泻的主要病原之一〔1〕。肠毒素大肠杆菌致病因子包括:粘附素(adhesion)、肠毒素(Enterotoxins)、水肿病毒素(edema disease princ 相似文献
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为了解中国牦牛产志贺毒素的大肠杆菌(Shiga toxin-producing Escherichia coli, STEC)中主要黏附因子的流行情况,采用PCR方法对来自四川甘孜阿坝等地区健康牦牛的70株STEC的eae、saa、iha 3种与黏附相关的毒力基因进行检测,并对部分含有相关黏附因子的阳性分离株的毒力基因进行了克隆及序列分析。结果显示,牦牛STEC中saa、iha的阳性率分别为71.42%(50/70)和78.57%(55/70),无eae基因序列(0/70),saa、iha的测序结果与GenBank上序列的同源性分别为100%和93%~99%。健康牦牛分离的STEC无LEE毒力岛编码eae,其他的一些与黏附相关的主要毒力基因saa、iha的携带率较高。 相似文献
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为了解中国川西北牦牛肉中产志贺毒素大肠杆菌(STEC)的携带情况及stx2的亚型和特征,试验将采集的204份川西北牦牛肉样品(各25g)增菌培养后,每份挑取5个可疑菌落,采用stx1、stx2双重PCR方法检测STEC,对分离株中的stx2分型并克隆测定stx2编码区序列。结果显示,在204份样品中分离出8株STEC,平均分离率为3.9%(8/204);存在4个不同的O血清型,分别为O38(4)、O50(1)、O74(2)、O150(1);在6株含有stx2的菌株中,其中有2株为stx2a型、4株为stx2c型。结果表明牦牛源分离株氨基酸序列与人源和牛源菌株同源性较高;由stx2A、B亚基的氨基酸序列系统进化树可知,牦牛源分离株与人源、牛源菌株聚为一支,表明它们之间遗传距离相对较近,牦牛源stx2各自分布在自己的小分支中,表明牦牛源STEC stx2与人源和牛源stx2相比,尽管亲缘关系较近,但仍存在一定程度的差异。 相似文献
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大肠杆菌O157和其它产志贺毒素大肠杆菌的毒力因子——粘附素 总被引:3,自引:0,他引:3
大肠杆菌O157的致病性已引起全世界公众和微生物学家的关注,而O157的致病因子有很多,本文就大肠杆菌O157可能的粘附素:菌毛、OMP及紧密素在致病中的作用进行综合评价,并对这些因子在其它产志贺毒素大肠杆菌中的出现率及与致病的关系进行分析,以期对大肠杆菌O157的致病机理有一个比较清楚的认识,推动我国对大肠杆菌O157的研究,以填补我国在这方面的相对空白。 相似文献
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本研究的目的是通过调查新疆地区分离的牛源产志贺毒素大肠杆菌(STEC)的耐药表型和基因型,掌握STEC耐药性的发展和传播规律。本研究对新疆6个地区的牛源(非O157:H7)STEC分离株进行了18种抗生素的药物敏感性试验,并检测菌株中携带的超广谱β-内酰胺酶(ESBLs)基因。结果显示:4.31%STEC表现为多重耐药,1.91%为产ESBLs菌株。检测到的主要ESBLs基因包括blaTEM和blaCTX-M。这是首次在新疆STEC中检测到blaTEM和blaCTX-M。本研究分离出的多数多重耐药STEC属于系统发育A群。多重耐药STEC可能是由非致病性大肠杆菌获得毒性和耐药基因而形成的。抗生素的选择压力可能对细菌在牛肠道中的定植表现出一定竞争优势,从而增加了耐药STEC对食物的污染。 相似文献
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XUE Tao LI Li GAO Qing-qing CHEN Xian-liang LI Tian-tian QU Xin-qin GAO Song 《中国畜牧兽医》2017,44(10):2878-2885
This study was aimed to understand the relationship of virulence gene distribution and genetic evolution between cattle originated Shiga toxin-producing Escherichia coli (STEC) and human originated enterohaemorrhagic Escherichia coli (EHEC) O157. This experiment collected 18 strains STEC in a dairy farm from Jiangsu province and 9 STEC reference strains (human, sheep, swine and avian), according to the method of U.S. Centers for Disease Prevention and Control Center (PulseNet), using the XbaⅠ enzyme digestion and pulsed field gel electrophoresis (PFGE) analysis, virulence genes were detected in some STEC isolates. The virulence gene distribution of O157 from different origin was remarkably different. The cattle originated STEC O157 and the human originated EHEC O157:H7 (EDL933W) had the most similar virulence gene distribution. In contrast, virulence genes were lack in cattle STEC O18 and O26, even though the cattle STEC O18 and O26 had the similar genotype as human EHEC O157:H7 (EDL933W). PFGE of Xba Ⅰ digested chromosomal DNA from 27 isolates of STEC exhibited 22 profiles. In general,the Dice coefficients of different originated STEC ranged from 72% to 100%.Cattle STEC O157 had a high similarity with two strains of human originated EHEC O157, while a low similarity was demonstrated between cattle STEC O157 and STEC O157 of swine and avian. The Dice coefficients of the cattle STEC O157 and the two strains of human EHEC O157 ranged from 83% to 95%. The Dice coefficients of cattle STEC O26 (Ⅶ,Ⅷ) and the two strains of human EHEC O157 were more than 82%. Therefore, it was concluded that the cattle STEC O157 and human EHEC O157 had a closer relationship in terms of virulence gene distribution and in genetic evolution. 相似文献
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为了探讨牛源产志贺毒素大肠杆菌(Shiga toxin-producing Escherichia coli,STEC)分离株在毒力基因分布和遗传进化方面与人源EHEC O157菌株之间的关系,本试验选择收集来自江苏某奶牛场的STEC菌株18株以及人源、羊源、猪源、禽源STEC参考菌株9株,参照美国疾病预防控制中心PulseNet推荐的方法,运用XbaⅠ酶进行酶切并完成脉冲肠凝胶电泳(PFGE)分型和聚类分析;同时对部分STEC菌株进行毒力基因检测。结果表明,经毒力基因检测,不同来源的O157菌株毒力基因分布不尽相同,其中牛源STEC O157与参考株EHEC O157∶H7(EDL933W)的基因排谱最为相近;牛源STEC O18和O26的基因排谱与参考株EHEC O157∶H7(EDL933W)类似,但存在部分基因的缺失。对27株不同来源的STEC分离株进行PFGE,产生了22种不同的酶切图谱。总体来看,不同来源的STEC Dice相似性系数在72%~100%之间。牛源O157分离株与猪源及禽源O157菌株的相似度偏低,而与两株人源O157分离株的相似度偏高,Dice相似性系数在83%~95%之间,牛源O26(克隆群Ⅶ、Ⅷ)与人源O157的相似性系数 > 82%。显然,从牛群中分离到的部分STEC菌株与人源EHEC O157具有较近的遗传进化关系。 相似文献
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大肠杆菌毒力因子研究概况 总被引:17,自引:0,他引:17
致病性大肠杆菌的毒力因子主要有黏附素、毒素、外膜蛋白 ( OMP)及铁转运系统等。在大肠杆菌侵袭宿主组织并引起其发病的过程中 ,这些毒力因子相互协调、发挥作用。文章对毒力因子的致病作用、致病机理、免疫原性及其在疾病防制中的应用几个方面的研究概况作了综述 ,为防制大肠杆菌病、研制新型高效的大肠杆菌疫苗提供了理论依据。另外 ,文章还介绍了近年来已相继研制成功的全菌体疫苗、纯化菌毛疫苗、单价或多价基因工程菌毛疫苗以及重组肠毒素双价基因工程苗、OMP亚单位疫苗等。展现了新型疫苗的研制 ,给防制大肠杆菌病带来了新的前景以及大肠杆菌作为工程菌的应用对畜禽其他疾病防制的推动作用 相似文献
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Kentaro OKUNO Sharda Prasad AWASTHI Germn A. KOPPRIO Atsushi IGUCHI Noritoshi HATANAKA Atsushi HINENOYA Rubn Jos LARA Shinji YAMASAKI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(4):630
The aims of this study were to investigate prevalence, O-genotype, and virulence gene profile including Shiga toxin (Stx) 2 gene-subtype of Stx-producing Escherichia coli (STEC) in beef cattle from the Bahía Blanca in Argentina. Rectal swabs were collected from 283 beef cattle in 2012. stx genes were detected in 90 (32%) out of the 283 rectal swabs by stx gene-specific PCR assay. The positive cases were 13 with stx1, 58 with stx2, and 19 with both stx1 and stx2. Among 90 stx gene-positive samples, 45 STEC strains were isolated, which included 3 stx1, 34 stx2, and eight stx1 and stx2 genes positive isolates. O-genotyping grouped 45 STEC strains into 19 different O-genotypes such as Og8, Og145, Og171, Og185 (4 from each), Og22, Og153, Og157 (3 from each) and others. Various stx2 gene-subtypes were identified in 42 STEC strains: 13 positive cases for stx2a, 11 for stx2c, 3 for stx2g, 10 for stx2a and stx2d, 4 for stx2a and stx2c, and 1 for stx2b, stx2c and stx2g. efaI gene, generally prevalent in clinical strains, was detected in relatively high in the STEC strains. These data suggest that stx2a and stx2c were distributed not only in O145 and O157 but also in minor O-genotypes of STEC in Argentina. 相似文献
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旨在了解新疆牛、羊和骆驼源产志贺毒素大肠埃希菌(Shiga toxin-producing Escherichia coli,STEC)的系统进化分群、血清群、毒力基因、耐药性及其遗传多样性,本研究采用PCR方法对牛、羊和骆驼源STEC进行了系统发育分群、血清群和毒力基因stx1、stx2(包括亚型)、eaeA、hlyA检测,通过K-B纸片法对分离株进行药物敏感性检测,并对其进行ERIC-PCR基因分型。结果表明:94株非O157 STEC以B1群为主,含9个血清群,包括O146(n=14)、O22(n=7)、O3(n=4)、O168(n=4)、O8(n=3)、O167(n=2)、O88(n=1)、O112ab (n=1)和O147(n=1)。毒力基因检测显示,46.8%(44/94)仅携带stx1,6.4%(6/94)仅携带stx2,46.8%(44/94)同时携带stx1+stx2。羊源STEC以携带stx1+hlyA为主(68.0%);牛源STEC以携带stx1+stx2+hlyA为主(57.9%);骆驼源STEC以携带stx1+hlyA为主(25.0%)。stx1a主要分布于牛源STEC,stx1c主要分布于羊源STEC。14株(14.9%)为耐药菌,对头孢他啶、四环素、头孢噻肟、氨苄西林和氨曲南的耐药率为3.2%~5.3%,对复方新诺明、头孢吡肟、哌拉西林-他唑巴坦、氨苄西林-舒巴坦、阿莫西林-克拉维酸和多黏菌素B的耐药率为1.1%~2.1%。ERIC-PCR结果显示牛、羊和骆驼源STEC亲缘关系较近。牛、羊和骆驼携带多种已知血清群STEC,贮存丰富的毒力基因,存在感染人类的风险,应在屠宰加工过程中予以预防和控制。 相似文献
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Sánchez S García-Sánchez A Martínez R Blanco J Blanco JE Blanco M Dahbi G Mora A Hermoso de Mendoza J Alonso JM Rey J 《Veterinary journal (London, England : 1997)》2009,180(3):384-388
Shiga toxin-producing Escherichia coli (STEC) are an important group of emerging pathogens, with ruminants recognised as their main natural reservoir. The aim of this work was to establish the prevalence of non-O157 STEC in free-ranging wild ruminants in the Extremadura region of Spain and to characterise them phenogenotypically. Faecal samples were collected from 243 wild ruminants, including Cervus elaphus, Capreolus capreolus, Dama dama and Ovis musimon and were examined for STEC using both phenotypic (Vero cells) and genotypic (PCR and PFGE) methods.Shiga toxin-producing Escherichia coli were isolated from 58 (23.9%) of the samples and a total of 65 isolates were characterised. A PCR method indicated that 11 (16.9%) strains carried the stx1 gene, 44 (67.7%) carried the stx2 gene and 10 (15.4%) carried both these genes. The ehxA gene was detected in 37 (57%) of the isolates but none contained either the eae or saa genes. The isolates were from a total of 12 ‘O’ serogroups, although 80% were restricted to the O2, O8, O128, O146, O166 and O174 serogroups. The most commonly isolated STEC bacteria, which were from the O146 serogroup, exhibited a high degree of polymorphism as indicated by PFGE. Shiga toxin-producing Escherichia coli isolates of serogroups O20, O25, O166, O171, O174 and O176 had not previously been found in wild ruminants. This is the first study to confirm that wild ruminants in Spain are a reservoir of STEC and are thus a potential source of human infection. 相似文献