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1.
为研究致鹅卵黄性腹膜炎大肠杆菌(E.coli) fimFGH基因的变异情况,本实验根据GenBank中登录的序列设计引物,PCR扩增了3株致鹩卵黄性腹膜炎性E.coli E0238、E0239、E0240 Ⅰ型菌毛的fimFGH基因并测序.序列比对分析结果表明,3株细菌的fimF、fimG和fimH基因及其所编码的蛋白... 相似文献
2.
禽大肠杆菌的分离与16S rRNA的鉴定 总被引：9，自引：4，他引：5
从疑似患有大肠杆菌病的病死鸡群中采取粪便样品,分离病原进行生化鉴定,从8份样品中分离鉴定出6株大肠杆菌。根据细菌16S rRNA 基因的高度保守性,设计合成大肠杆菌的共同引物,对随机选取的1株细菌进行PCR扩增,并与GenBank中的E.coli 16S rRNA进行序列比对,确定这株细菌与大肠杆菌的同源性达99%以上。本方法特异性好,为实验室鉴定大肠杆菌提供了一种简单、容易操作的手段。 相似文献
3.
《现代畜牧兽医》2021,(3)
为有效防治鹅大肠杆菌病并分析其耐药性,无菌采集疑似大肠杆菌感染鹅的肝脏、脾脏等组织,进行细菌分离培养、生化鉴定、PCR鉴定、16S rRNA序列比对。结果表明,所分离的细菌为大肠杆菌。通过血清凝集试验,鉴定其主要血清型为O88、O171、O59、O27。应用小鼠对4种血清型代表菌株进行致病性试验,结果分离的菌株致小鼠发病率为92.5%,死亡率为87.5%,表现腹腔有纤维素性渗出物,肝淤血肿大且表面有纤维素性伪膜等病理变化。对代表菌株采用微量肉汤稀释法进行药敏试验,结果显示,分离株对甲氧苄啶、磺胺异恶唑敏感,对黏杆菌素、美罗塔南等11种临床常用药物高度耐药。研究表明,从辽宁省黑山县分离的鹅大肠杆菌具有较强的致病性和较高的耐药性。 相似文献
4.
从发病雏鹅肝脏中分离到1株细菌,根据培养特性、镜检结果、生化特征、血清学分型及PCR检测结果,表明分离茵为鼠伤寒沙门菌.动物试验结果表明,分离菌可致死雏鹅;药敏试验表明,该菌对环丙沙星、痢特灵、茵必治、阿米卡星、链霉素等药物敏感,对利福平和四环素耐药,与其它家禽或水禽来源的沙门菌相比,该分离株耐药性不严重.将分离茵16SrDNA基因进行扩增,PCR产物经胶回收试剂盒纯化后测序,序列Blast分析与血清型鉴定一致.将序列与GenBank上已登录的29株不同来源的鼠伤寒沙门茵序列进行比较,构建系统进化树,结果显示分离菌与美国分离的VDL-SS334株位置最为接近,同源性为95.9％. 相似文献
5.
从病死母猪肺脏中分离到一株革兰氏阴性小杆菌,用生理生化鉴定、药敏试验、致病性试验和PCR鉴定方法对分离菌株进行鉴定,并用多杀性巴氏杆菌荚膜分型引物对分离株的荚膜血清型进行鉴定。结果表明:本菌为猪多杀性巴氏杆菌,对多种抗生素高度敏感,对小白鼠有强致病性;PCR扩增16SrDNA基因获得1415bp片段,分离株的16SrDNA核苷酸序列与多杀性巴氏杆菌(AY078999)的同源性为99%,因此该分离菌株被鉴定为致病性巴氏杆菌,命名为YN20110122株;本菌分离株为荚膜A型血清型多杀性巴氏杆菌。 相似文献
6.
《畜牧与饲料科学》2017,(6)
旨在确定引起安徽地区猪场仔猪黄痢发生的病原菌种类,并从分子水平上揭示其多重耐药机制。利用麦康凯培养基对从仔猪黄痢病死猪肝脏样本中初步分离到的9株细菌进行选择性培养;提取分离菌株的基因组DNA,利用PCR法扩增其16SrDNA序列并进行测序;将测序结果提呈至NCBI数据库,与GenBank中已发表的序列进行BLAST比对,对分离菌株进行种水平鉴定;采用纸片扩散法开展分离菌株对抗菌药物的敏感性试验;利用PCR法检测分离菌株携带多重耐药基因AcrA的情况。结果表明,9株分离菌在麦康凯琼脂培养上均呈中等大小的玫瑰红色菌落,符合大肠杆菌的菌落特征;9株分离菌的16SrDNA序列与GenBank中公布的大肠杆菌16SrDNA序列的相似性均在99.0%以上,提示分离菌株均为大肠杆菌;9株分离菌对12种抗菌药物呈现不同程度的耐药性,对阿米卡星、大观霉素和氯霉素的耐药性较强;9株分离菌的AcrA基因携带率为100%。综上提示,多重耐药性大肠杆菌是引起该地区猪场仔猪黄痢发生的致病菌,在临床治疗中应引起足够重视。 相似文献
7.
从病死犬病料中分离到1株类志贺邻单胞菌,并对该菌做了生理生化鉴定、药敏试验,致病性试验。结果表明,本菌对多种抗生素耐药,其庆大霉素耐药机制与所携带的质粒相关;本菌对小白鼠有强致病性,其LD50为1．6×10^7.4CFU。用PCR方法扩增分离菌株16SrDNA基因并测序,并将其与GenBank上其他细菌16SrDNA核苷酸序列进行同源性分析。结果表明,分离株的16SrDNA核苷酸序列与类志贺邻单胞菌（GQ359962．1）的同源性为98％,因此将该分离菌株鉴定为致病性肠球菌,命名为YN-1株（云南-1株）。 相似文献
8.
潘永娜 《畜牧兽医科技信息》2013,(11):16
本试验从普兰店地区部分养鸡场采集具有典型临诊特征的鸡大肠杆菌病的病、死鸡病料,进行细菌分离培养和鉴定,分离到17株鸡大肠杆菌。对此17株大肠杆菌进行血清型鉴定,鉴定出血清型15株,分别属于O18、O15、O8、O78、O35,其中O35血清型共6株,占定型菌株的40%;O18血清型共5株,占定型菌株的33.3%。结果表明O35型和O18型鸡大肠杆菌为普兰店地区优势流行血清型。1病料采集鸡大肠杆菌病主要临诊表现有脐炎型、急性败血型、气囊炎型、全眼球炎型、卵黄性腹膜炎型。败血症型在临床上主要表现为纤维 相似文献
9.
《养禽与禽病防治》2018,(11)
鸡大肠杆菌病是由大肠埃希菌的某些血清型引起的细菌性疾病,近几年来,由大肠杆菌引起的疾病逐年增多,病情复杂且混合感染,大肠杆菌可引起鸡的脐炎、气囊炎、眼球炎、心包炎、败血症、卵黄性腹膜炎及输卵管炎,一旦暴发常常给养殖户造成严重的经济损失。2016-2017年间,从滨州市3个县多家养殖场分离到10株大肠杆菌,并且进行了培养分离、显微镜下形态学观察和生化鉴定。对菌株进行大肠杆菌O抗原鉴定,共有O1(3株)、O2(2株)、O24(2株)和O7(3株)。分离菌株有高致病性。通过药敏试验结果分析发现大肠杆菌耐药性严重,多重耐药且耐药谱复杂。药敏试验结果表明,大肠杆菌对新霉素、恩诺沙星、阿奇霉素和头孢哌舒等较为敏感。新霉素与磷霉素、阿奇霉素和头孢哌舒之间的药物组合,效果更好。 相似文献
10.
《中国预防兽医学报》2017,(3)
为分析邢台地区致鸡卵黄性腹膜炎大肠杆菌(E.coli)分离株的血清型、毒力基因和耐药性,本实验采用常规鉴定方法和16S rRNA PCR的方法,从邢台地区不同养鸡场46份患卵黄性腹膜炎的40周龄~45周龄蛋鸡病料组织中分离鉴定出37株E.coli。人工感染1日龄的雏鸡,结果显示32株分离菌为致病性E.coli,采用玻板凝集法检测其血清型分布,结果显示定型的27株致病性E.coli分离株共属于11个血清型,以O_(78)、O_(148)、O_2及O_8为优势血清型。采用PCR方法检测32株致病性E.coli分离株14种毒力基因,其中irp2、fyuA、ompT、Iss~a、iucD~a、iutA、iroN、hlyF、fimC毒力基因检出率最高,分别为100%、96.9%、93.8%、86.7%、84.3%、71.9%、65.7%、56.3%和50%,其余毒力基因检出率较低。耐药性分析结果显示,32株致病性E.coli分离株仅对头孢克肟、左氧氟沙星、阿奇霉素、头孢曲松和氟苯尼考5种药物高度敏感,对其他药物存在不同程度的耐药性。本研究为防治致病性E.coli引起蛋鸡卵黄性腹膜炎提供了实验依据。 相似文献
11.
The study attempted to investigate the occurrence of non-O157 E. coli serogroups O26, O103, O111 and O145 in cattle at slaughter and to determine the virulence potential of these isolates. A total of 399 fecal samples were analyzed by selective plating and E. coli isolates were characterized by polymerase chain reaction (PCR) for the genes vtx1, vtx2, eae and EHEC hlyA. Immunomagnetic separation (IMS) is required to increase the efficiency of the isolation procedure. E. coli O26, O103, O111 and O145 were recovered from 24 (6%) fecal samples. E. coli O26 and O103 seemed to be more abundant in slaughter cattle than E. coli O111 and O145. Sixteen out of the 24 isolates harbored vtx genes. All vtx-positive isolates harbored one or more additional virulence factors. Six out of the 8 vtx-negative isolates harbored eae and/or EHEC hlyA, whereas 2 strains harbored none of the tested virulence genes. 相似文献
12.
The aim of this study was to evaluate a Chemiluminescence Enzyme Immunoassay (CLIA) developed for the detection of E. coli O157:H7, using different E. coli O157 serotypes. The sensitivity and specificity of the kit were determined from the tenfold dilutions of the 24-hour broth cultures of the test strains. According to the results obtained in this trial, the sensitivity of the kit is 10(3)-10(4) cells ml-1, and it is specific for E. coli O157. Twenty-five g ground raw beef samples were prepared and inoculated with E. coli O157:H7 at different CFU g-1. The samples were incubated in 225 ml of modified E. coli broth with novobiocin (mEC + n) at 42 degrees C for 4 h and the immunoassays were performed following the instructions of the manufacturer. According to the results obtained by the CLIA test 10(1)-10(2) E. coli O157 g-1 can be detected from the sample. So this kit seems to be suitable for screening the samples before selective cultivation of E. coli O157:H7. 相似文献
13.
These experiments determined the ability of Escherichia coli O157:H7 to colonize and persist in pigs simultaneously inoculated with other pathogenic E. coli strains. Three-months-old pigs were inoculated with a mixture of five E. coli strains. The mixture included two Shiga toxigenic E. coli (STEC) O157:H7 strains, two enterotoxigenic E. coli (ETEC) strains and one enteropathogenic E. coli (EPEC) strain. A high dose mixture with all five strains at 10(10)CFU/animal (CFU: colony forming units) and a low dose mixture with the STEC strains at 10(7)CFU and the EPEC and ETEC strains remaining at 10(10)CFU were used. The STEC strains persisted in the alimentary tracts of some pigs at 2 months post-inoculation, following inoculation with both the high and low dose mixtures. When all strains were given at 10(10)CFU (high dose) the STEC strains persisted in greater numbers and in more pigs than did the other E. coli strains. The results demonstrated that persistent colonization (> or =2 months) by E. coli O157:H7 can occur in pigs. These findings were similar to those reported from sheep inoculated with the same mixture of E. coli strains. The results are consistent with reports suggesting that pigs have the potential to be reservoir hosts for STEC O157:H7. 相似文献
14.
Duplex real-time PCR assays were used as modules to cover partially automated detection of 12 genes encoding adhesins, enterotoxins and Shiga toxins in faecal E. coli isolates. For this a total of 194 E. coli isolates from pigs suffering from post-weaning diarrhoea (PWD), including 65 isolates with haemolytic activity, and 83 isolates from calves with diarrhoea were examined. Data obtained by PCR were compared with O-typing and with haemolytic activity as indirect virulence markers. E. coli O-types O139:K82, O141:K85, and O149:K91 accounted for 43.8% (n = 85) of all porcine strains and for 55.4% (n = 36) of the porcine strains, which exhibited haemolytic activity. These strains carried virulence genes by 65.9% (n = 56) and 80.6% (haemolytic E. coli, n = 29), respectively. The E. coli O-types O139:K82 and O141:K85 were significantly associated with the adhesin gene F18, and O149:K81 with the F4 gene. In this context, detection of the gene encoding F18 was coupled predominantly with the genes responsible for the production of the toxins ST-I, ST-II and Stx2, and the F4 gene with those of the enterotoxins ST-I, ST-II and LT. Both virulence patterns were detected more pronounced in E. coli strains with haemolytic activity. Fifty-six of a total of 83 E. coli isolates originating from calves were O-typed as O101 (O101:K28, O101:K30, O101:K32; n = 29), O78:K80 (n = 23), and O9:K35 (n = 4). Most of the E. coli O78:K80 strains carried the F17 gene (69.6%, n = 16). Virulence genes encoding for F4, F5 or ST-I were detected only in single cases. Intimin and Shiga toxin genes that are present in enterohaemorrhagic E. coli (EHEC) were not detected. 相似文献
15.
对从天津地区分离到的71株鸡大肠杆菌的部分生物学特性包括致病性、血清型、耐药特性和免疫原性等进行了研究。结果表明其中60株为致病性菌株,占分离菌株的84.5%;60个致病性菌株共定型出45个菌株,分属O1、O2、O5、O6、O20、O45、O53、O74、O75、O78、O88、O89、O92、O107、O111、O145等16个血清型,其中O78、O88、O2、O45、O53和O145为优势血清型,占定型菌株的73.4%;试验菌株具有广泛的耐药性,60个致病性菌株均为多重耐药。免疫原性测定试验结果表明,O2、O78、O88血清型菌株均可对相同血清型菌株提供很好的保护,但3个血清型菌株之间缺乏有效的保护。 相似文献
16.
To determine if Escherichia coli O157:H7 is capable of residing in the gall bladder of cattle, inoculation studies were conducted with O157:H7 strain 86-24 in weaned Holstein calves. Strain 86-24 was isolated from the gall bladders of five calves 36 days after inoculation. Two other calves contained the inoculation strain in the distal colon but the organism was absent in their gall bladders. A second trial in which the calves were euthanized 15 days after inoculation found strain 86-24 in six of seven inoculated calves but only in colon and/or rumen samples. In a third trial that inoculated eight calves with a four-strain cocktail of O157:H7 strains, the gall bladders from all eight animals were positive 9 days after inoculation. The colon and rumen samples from these calves were also positive. E. coli O157:H7 isolates recovered from bile samples and subtyped by pulsed field gel electrophoresis found that three of the four inoculation strains were present in one or more of the calves. Thus, residence in the gall bladder is not restricted to a single strain. Additional evidence of the ability to localize in the gall bladder of cattle was provided by testing the bile from 150 gall bladders (five collection dates, 30 samples each) obtained at an abbatoir and the isolation of E. coli O157:H7 from four samples (2.7%). This study establishes that E. coli O157:H7 can reside transiently or permanently at a low level in the gall bladder of cattle. 相似文献
17.
Mercado EC Rodríguez SM D'Antuono AL Cipolla AL Elizondo AM Rossetti CA Malena R Méndez MA 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2003,50(1):8-13
CS31A is a K88-related non-fimbrial adhesin first described on Escherichia coli strains isolated from diarrhoeic and septicaemic calves. In this report, CS31A antigen was screened by immunological methods and confirmed by PCR among bovine E. coli isolates. In addition, CS31A-producing strains were characterized with respect to different fimbrial antigens, O-serogroup and other properties related to virulence. Faecal or tissue specimens of 100 diarrhoeic or septicaemic calves and 27 older cattle with different pathologies from 71 outbreaks or individual cases that occurred in Buenos Aires province, Argentina, were examined. CS31A + E. coli strains were isolated from 21 (21.0%) calves from 16 outbreaks or individual cases. No CS31A + E. coli was detected in samples from cattle more than 1 year old. Fimbriae F5, F41, F17a and F17b were not detected among the CS31A-producing strains. Three (14.3%) of the CS31A+ E. coli strains expressed the F17c fimbria. All of the 21 isolates exhibited at least one property of septicaemic strains (resistance to serum, production of aerobactin or colicins) but none of them demonstrated heat-stable enterotoxigenic activity. CS31A + E. coli isolates belonged to 10 serogroups, more commonly O8, O7, O17 and O21. The results obtained here confirm the worldwide distribution of CS31A antigen in bovine E. coli strains. However, CS31A + or CS31A + /F17c + E. coli were less frequently isolated than they were in North hemisphere countries. 相似文献
18.
从肿头综合征鸡分离出产Vero毒素E.coli 总被引：1，自引：1，他引：0
本研究从哈尔滨郊区某鸡场肿头综合征（ Ｓ Ｈ Ｓ）鸡分离出 ３ 株血清型为 Ｏ７８ 的埃希氏大肠杆菌（ Ｅ．ｃｏｌｉ）,从鞍山 Ｓ Ｈ Ｓ病料分离出 １ 株血清型为 Ｏ８ 的 Ｅ．ｃｏｌｉ。并证实这 ４ 株 Ｅ．ｃｏｌｉ 能够对 Ｖｅｒｏ 细胞产生毒性作用,与产 Ｖｅｒｏ 毒素的 Ｅ．ｃｏｌｉ一致。对哈尔滨市郊 Ｓ Ｈ Ｓ病鸡做病理组织学观察,主要变化为头部皮下组织,头盖骨气室及鼻粘膜下纤维素性化脓性炎症,水肿和大肠杆菌性肉芽肿,心、肝、肾等器官炎症变化并有大量异嗜性粒细胞和细菌团块。 相似文献
19.
A cross-sectional study was conducted to determine the prevalence and characteristics of verocytotoxigenic Escherichia coli (VTEC) on 25 dairy farms each located in Waller field and Carlsen field farming areas in Trinidad. On each selected farm, faecal samples were collected from milking cows, calves and humans; rectal swabs were obtained from pet farm dogs; bulk milk was sampled as well as effluent from the milking parlour. Escherichia coli was isolated from all sources on selective media using standard methods. Isolates of E. coli were subjected to slide agglutination test using E. coli O157 antiserum, vero cell cytotoxicity assay to detect verocytotoxin (VT) and heat labile toxin (LT) production, the polymerase chain reaction (PCR) to detect VT genes, and the dry spot test to screen for E. coli O157 and non-O157 strains. In addition, faecal samples from animal and human sources were tested for VT genes using PCR. Of a total of 933 E. coli isolates tested by the slide test, eight (0.9%) were positive for the O157 strain. The vero cell cytotoxicity assay detected VT-producing strains of E. coli in 16.6%, 14.6%, 3.2% and 7.1% of isolates from cows, calves, farm dogs and humans respectively (P < 0.05; chi(2)). For LT production, the highest frequency was detected amongst isolates of E. coli from calves (10.8%) and the lowest (0.0%) amongst isolates from humans and bulk milk (P < 0.05; chi(2)). Of the 61 VT-producing isolates by vero cell cytotoxicity assay tested by PCR, the VT, LT and eae genes were detected in 62.3%, 4.9% and 1.6% respectively (P < 0.05; chi(2)). Amongst the 45 E. coli isolates that were VT positive (vero cell) or VT-gene positive by PCR, 2.2%, 2.2%, 4.4% and 6.7% belonged to non-O157 strains O91, O111, O103 and O157, respectively, as determined by the Dry spot test. Detection of VTEC strains in milk and dairy animals poses a health risk to consumers of milk originating from these farms. In addition, the demonstration of VTEC strains in humans, VT gene in faecal samples and E. coli isolates as well as non-O157 VTEC strains of E. coli are being documented for the first time in the country. 相似文献
20.
为调查新疆部分地区E.coli O157：H7的感染情况和菌株致病性,从新疆阿克苏、伊犁、塔城3个地区的牛场采集新鲜粪样564份,对E.coli O157：H7进行分离与鉴定。利用E.coli营养肉汤（EC肉汤）对样品进行增菌后,用山梨醇麦康凯培养基（SMAC）平板选择性培养,再经过4-甲基伞形酮-β-D葡萄糖醛酸苷培养基（MUG）的筛选,对疑似菌株进行生化和PCR鉴定,并将分离鉴定到的菌株进行小鼠攻毒试验。结果显示,从伊犁地区采集的样品中共分离出2株E.coli O157：H7（Y166和Y226）,其检出率为0.88%;小鼠攻毒试验中,Y166和Y226试验组小鼠在48 h内全部死亡,具有一定致病性;从阿克苏、塔城所采样品中未分离到E.coli O157：H7。 相似文献