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1.
六十二株水貂源大肠杆菌分离株耐药表型与耐药基因及克隆菌群分析 总被引：2，自引：2，他引：0
为了调查诸城地区某水貂养殖场粪便源大肠杆菌的表观及其分子特征,采集某个水貂养殖场的水貂粪便进行大肠杆菌分离鉴定,对分离鉴定的大肠杆菌进行血清型鉴定和对14种常见抗菌药物的耐药表型鉴定;使用PCR检测耐药基因以及Ⅰ整合子基因盒的携带情况,利用多位点序列分型（MLST）来分析菌株的克隆关系并构建系统发育树来分析相同克隆群菌株的遗传相似性。结果显示,自82份水貂粪便样品分离到62株大肠杆菌,分离率75.61%;大肠杆菌分离株对AMP和TET的耐药率超过90%,多重耐药菌株（MDR）占比为85.48%。PCR检测到5类耐药基因的存在,qnrS检出率最高,为61.29%（38/62）;aaC2、aaC4、sul1和aac（6'）-Ib-cr耐药基因与菌株产生相应的耐药抗性存在一致性（P<0.01）。分离菌株中Ⅰ类整合子可变区域的优势结构为dfrA27-aadA2-qnrA。鉴定出致病性血清型的存在,且对应菌株都具有多重耐药性,优势血清型为O104：H4。分离株中存在33个STs,ST46为优势STs（16.13%）,具有3个主要克隆群,依次为CC10、CC46和CC176;与致病性相关菌株的STs和人源大肠杆菌具有共同的遗传背景。本研究表明,养殖场的水貂受到致病性和多重耐药性大肠杆菌的污染,相同克隆群菌株的耐药基因分布具有多态性,表观特征差异明显。 相似文献
2.
奶牛粪中致病性大肠杆菌的分离鉴定及生物学特性的研究 总被引：2，自引：0，他引：2
对呼和浩特市地区不同奶牛场共20头健康荷斯坦奶牛的鲜粪便进行了病原性大肠杆菌的分离提取,共分离到大肠杆菌40株,经鉴定病原性大肠杆菌6株,均为强毒株,占分离菌数的15.0%,而34株为非致病性大肠杆菌,占分离菌数的85.0%。同时对6株病原性大肠杆菌进行了病原性特性的研究,发现病原性菌的生化特性基本一致,与资料报道相符。对6株病原性大肠杆菌进行了抗"O"血清鉴定,除1株有自凝现象,其余5株分属O1、O2、O83个血清型,分别占定型菌株的20%、40%和40%。 相似文献
3.
《畜牧兽医学报》2019,(12)
为了调查诸城地区某水貂养殖场粪便源大肠杆菌的表观及其分子特征,采集某个水貂养殖场的水貂粪便进行大肠杆菌分离鉴定,对分离鉴定的大肠杆菌进行血清型鉴定和对14种常见抗菌药物的耐药表型鉴定;使用PCR检测耐药基因以及Ⅰ整合子基因盒的携带情况,利用多位点序列分型(MLST)来分析菌株的克隆关系并构建系统发育树来分析相同克隆群菌株的遗传相似性。结果显示,自82份水貂粪便样品分离到62株大肠杆菌,分离率75.61%;大肠杆菌分离株对AMP和TET的耐药率超过90%,多重耐药菌株(MDR)占比为85.48%。PCR检测到5类耐药基因的存在,qnrS检出率最高,为61.29%(38/62);aaC2、aaC4、sul1和aac(6′)-Ib-cr耐药基因与菌株产生相应的耐药抗性存在一致性(P0.01)。分离菌株中Ⅰ类整合子可变区域的优势结构为dfrA27-aadA2-qnrA。鉴定出致病性血清型的存在,且对应菌株都具有多重耐药性,优势血清型为O104:H4。分离株中存在33个STs,ST46为优势STs(16.13%),具有3个主要克隆群,依次为CC10、CC46和CC176;与致病性相关菌株的STs和人源大肠杆菌具有共同的遗传背景。本研究表明,养殖场的水貂受到致病性和多重耐药性大肠杆菌的污染,相同克隆群菌株的耐药基因分布具有多态性,表观特征差异明显。 相似文献
4.
仔猪腹泻致病性大肠杆菌分型鉴定及耐药性分析 总被引：1，自引：1，他引：0
为了解贵州省规模化养猪场腹泻仔猪致病性大肠杆菌流行情况及耐药性变化,本研究运用凝集试验、PCR和药敏纸片琼脂扩散法等方法对分离的78株致病性大肠杆菌进行血清型、毒力基因及耐药性分析。结果显示,78株致病性大肠杆菌以O138、O87血清型为主,占定型菌株的60.8%;其中62株致病性大肠杆菌检出毒力基因,检出率为79.5%,可分为8种毒力基因类型,分属肠致病性大肠杆菌（EPEC）、肠产毒性大肠杆菌（ETEC）和肠聚集性大肠杆菌（EAEC）,毒力基因eaeA、elt和escV检出率较高,分别为38.5%、28.2%和21.8%;分离到的致病性大肠杆菌对β-内酰胺类药物高度耐药,均为多重耐药株,耐药种类可达8种以上。结果表明,当前贵州省规模化养猪场腹泻仔猪致病性大肠杆菌的毒力基因检出率较高且基因型复杂,耐药性严重。本试验结果可为规模化养猪场防控仔猪腹泻提供基础资料及理论依据。 相似文献
5.
【目的】了解河北地区动物源大肠杆菌分离菌株的耐药情况和各耐药菌株之间的亲缘关系,为有效防控大肠杆菌耐药性的产生提供科学依据。【方法】从河北省某养殖场采集健康动物的粪便样本297份(鸡源48份、猪源249份),通过细菌分离纯化和PCR扩增对分离菌株进行鉴定,采用药敏试验确定分离菌株的耐药表型,并对其进行耐药基因检测、血清型鉴定、系统发育群分析、质粒复制子分型和基因分型鉴定。【结果】分离菌株在麦康凯培养基上呈粉红色圆形菌落,经16S rDNA测序分析鉴定出129株大肠杆菌,其中92株大肠杆菌呈现多重耐药现象,主要以3～4耐为主,耐药基因以floR、tetA、qnrS和strB的检出率最高;多重耐药大肠杆菌以O132为优势血清型,系统进化群主要分布在A和B1群,主要流行质粒为IncFIB和IncN;经MLST分型获得27个ST型,主要为ST93型,其中12株序列型为未知型。【结论】河北地区健康动物肠道内大肠杆菌多重耐药现象较为严重,其血清型众多,分子特征呈现多样性,仍需加强对动物源大肠杆菌耐药性和分子特征的监测。 相似文献
6.
为了追踪由牛源致病性沙门杆菌造成的粪便污染源头,对内蒙古某奶牛场200头健康状况良好的泌乳荷斯坦奶牛的新鲜粪便进行了致病性沙门杆菌的分离鉴定.试验共分离出55株疑似沙门杆菌,再经过形态学观察、动物试验、生化鉴定和血清型鉴定从55株疑似沙门杆菌中分离出8株致病性沙门杆菌,分离率为14.5%(8/55),其菌型分布为A群(O2)、B群(O4)、C1亚群(O7)、D群(O9),其中B群所占比例最高(37.5%),其次是C1亚群(25.0%)、D群(25.0%)、A群(12.5%).在此基础上选用乌梅、黄芩、大黄、黄连、穿心莲、金银花、板蓝根、桂枝等8种中草药按照试管液体2倍稀释法进行药物最低抑菌浓度试验,结果表明,抑菌效果较好的药物是乌梅、黄芩、大黄;其他中草药对沙门杆菌抑菌效果较差或无抑制作用. 相似文献
7.
奶牛粪样中致病性大肠埃希菌的分离与鉴定 总被引：1，自引：0，他引：1
大肠埃希菌血清型众多,一些具有特殊血清型的大肠埃希菌对人和动物有致病性。本试验从包头市侯家营奶牛场77头外表健康成年泌乳荷斯坦奶牛采集新鲜粪样,进行细菌分离培养,共分离到疑似大肠埃希菌69株,经过形态观察、生化鉴定、动物致病性试验和血清型鉴定,其中12株为致病性大肠埃希菌,均为强毒株,占分离菌数的17.4%,另57株为非致病性大肠埃希菌,占分离菌数的82.6%。同时对12株致病性大肠埃希菌进行了"O"血清型鉴定,分属7种血清型O78、O6、O9、O98、O1、O8、O149,分别占定型菌株的25.0%(3/12)、8.3%(1/12)、16.7%(2/12)、8.3%(1/12)、8.3%(1/12)、8.3%(1/12)、25.0%(3/12)。 相似文献
8.
为了解河南省濮阳市致犊牛腹泻大肠杆菌的致病性、血清型、生物被膜形成能力及耐药性等生物学特性,对2018—2020年采集的243份腹泻犊牛肛拭子以及粪便、肝脏等病料样品进行大肠杆菌分离鉴定,采用人工感染小鼠试验、玻板凝集试验以及结晶紫微孔板法和K-B药敏纸片法,对分离的致病性大肠杆菌进行相关特性检测。结果显示：从243份病料样品中分离到87株致病性大肠杆菌,致病性大肠杆菌分离率为35.8%（87/243）;分离的致病性大肠杆菌分属于14种血清型,其中O101（18.4%）、O38（17.2%）和O142（14.9%）为优势血清型;分离的致病性大肠杆菌中,被膜形成能力强的24株（26.6%）,中等的34株（43.6%）,弱的17株（19.5%）,不形成的12株（15.4%）;分离的致病性大肠杆菌对阿莫西林、氨苄西林、链霉素10种药物的耐药率较高,均在49.4%以上。结果表明：致病性大肠杆菌在濮阳市可能呈地方性流行,O101、O38、O142为犊牛源优势血清型;该地的致病性大肠杆菌外界生存能力较强,且对多种临床常用药物产生了耐药性。因此,应采取综合防控措施,科学使用敏感抗菌药物,研制优势血清型多价疫苗,加强犊牛大肠杆菌性腹泻的防控。 相似文献
9.
10.
仔猪腹泻致病性大肠杆菌分型鉴定及耐药性分析 总被引：1，自引：1，他引：0
为了解贵州省规模化养猪场腹泻仔猪致病性大肠杆菌流行情况及耐药性变化,本研究运用凝集试验、PCR和药敏纸片琼脂扩散法等方法对分离的78株致病性大肠杆菌进行血清型、毒力基因及耐药性分析。结果显示,78株致病性大肠杆菌以O138、O87血清型为主,占定型菌株的60.8%;其中62株致病性大肠杆菌检出毒力基因,检出率为79.5%,可分为8种毒力基因类型,分属肠致病性大肠杆菌(EPEC)、肠产毒性大肠杆菌(ETEC)和肠聚集性大肠杆菌(EAEC),毒力基因eaeA、elt和escV检出率较高,分别为38.5%、28.2%和21.8%;分离到的致病性大肠杆菌对β-内酰胺类药物高度耐药,均为多重耐药株,耐药种类可达8种以上。结果表明,当前贵州省规模化养猪场腹泻仔猪致病性大肠杆菌的毒力基因检出率较高且基因型复杂,耐药性严重。本试验结果可为规模化养猪场防控仔猪腹泻提供基础资料及理论依据。 相似文献
11.
L Beutin 《Veterinary research》1999,30(2-3):285-298
Certain strains of Escherichia coli behave as pathogens in dogs and cats causing gastro-intestinal and extra-intestinal diseases. Among the five known groups of diarrhoeagenic E. coli, namely enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), shiga-toxin producing E. coli (STEC) and enteroaggregative E. coli (EAggEC), only EPEC and ETEC were clearly associated with enteric disease in young dogs. ETEC isolates from diarrhoeic dogs were found to be positive for the heat-stable enterotoxins STa and STb but negative for heat-labile enterotoxin (LT). Canine ETEC were found to be different from those of other animals and humans by their serotypes, production of alpha-haemolysin and adhesive factors and by the production of uncharacterized types of enterotoxins by some ETEC. Canine EPEC could be distinguished from EPEC of humans or other animals by their serotypes and by the eae-protein intimin which mediates intimate adherence of EPEC to intestinal mucosa cells. STEC were occasionally isolated from faeces of healthy and diarrhoeic dogs but their role in canine diarrhoea is not yet well known. EIEC and EAggEC were not reported to occur in dogs or cats. Very little is known on diarrhoegenic E. coli in cats and further epidemiological investigations on this subject are needed. Besides its role in gastro-intestinal infections, E. coli can cause infections of the urogenital tract and systemic disease in dogs and cats. Extra-intestinal pathogenic E. coli strains from dogs and cats belong to a limited number of serotypes and clonal groups and are frequently found as a part of the normal gut flora of these animals. Many of these E. coli strains carry P-fimbriae and produce alpha-haemolysin and a necrotizing cytotoxin (CNF1). Some of the frequently isolated types of extra-intestinal pathogenic E. coli from dogs, cats and humans were found to be highly genetically related but showed differences in their P-fimbrial adhesins which determine host specificity. Transmission of extra-intestinal and enteral pathogenic E. coli between dogs and humans was reported. Further research is needed, however, to determine the role of dogs and cats as transmission vectors of pathogenic E. coli strains to other animals and humans. 相似文献
12.
Avian pathogenic Escherichia coli (APEC) causes economically significant infections in poultry. The genetic diversity of APEC and phylogenetic relationships within and between APEC and other pathogenic E. coli are not yet well understood. We used multilocus sequence typing (MLST), PCR-based phylogrouping and virulence genotyping to analyse 75 avian E. coli strains, including 55 isolated from outbreaks of colisepticaemia and 20 from healthy chickens. Isolates were collected from 42 commercial layer and broiler chicken farms in Sri Lanka. MLST identified 61 sequence types (ST) with 44 being novel. The most frequent ST, ST48, was represented by only six isolates followed by ST117 with four isolates. Phylogenetic clusters based on MLST sequences were mostly comparable to phylogrouping by PCR and MLST further differentiated phylogroups B1 and D into two subgroups. Genotyping of 16 APEC associated virulence genes found that 27 of the clinical isolates and one isolate from a healthy chicken belonged to highly virulent genotype according to previously established classification schemes. We found that a combination of four genes, ompT, hlyF, iroN and papC, gave a comparable prediction to that of using five and nine genes by other studies. Four STs (ST10, ST48, ST117 and ST2016) contained APEC isolates from this study and human UPEC isolates reported by others, suggesting that these STs are potentially zoonotic. Our results enhanced the understanding of APEC population structure and virulence association. 相似文献
13.
Samples of faeces from 57 dogs with acute diarrhoea, 82 dogs with chronic diarrhoea, 34 clinically healthy household dogs and 88 kennelled control dogs were analysed by hybridisation, using DNA probes to detect enteropathogenic Escherichia coli (EPEC) and enterotoxigenic E coli (ETEC), verocytotoxin-producing E coli (VTEC), enterohaemorrhagic E coli (EHEC), enteroinvasive E coli (EIEC) and enteroaggregative E coli (EAggEC). Samples of duodenal juice from 60 of the 82 dogs with chronic diarrhoea were also examined. Significantly more of the dogs with diarrhoea were excreting EPEC (acute 35.1 per cent, chronic 31.7 per cent) and VTEC (acute 24.6 per cent, chronic 28 per cent) than the kennelled dogs (EPEC 17.1 per cent, VTEC 0 per cent) or the household control dogs (EPEC 6 per cent, VTEC 5.9 per cent). Enteropathic E coli was also detected in the duodenal juice of 23 of 60 (38.3 per cent) of the dogs with chronic diarrhoea. The EPEC attaching and effacing A (eaeA) gene and the verocytotoxin 1 (VR1) gene coding for VTEC were often found together. There was good agreement between in vitro studies and hybridisation for the detection of eaeA and VT1. Isolates from the dogs with diarrhoea adhered significantly more to Hep-2 cells, and VT1-positive strains from the dogs with diarrhoea consistently killed more than 50 per cent of Vero cells. 相似文献
14.
Mastitis has been recognized for some time as the most costly disease in dairy herds. From March 1997 to August 1998, 2144 samples of bovine mastitic milk were collected, from which 182 Escherichia coli isolates were made, and from which 141 isolates had the somatic antigen (serogroup) determined. Twelve different serogroups were isolated from mastitic milk, and among them were O26, O55, O111 and O119, all of them classic enteropathogenic E. coli (EPEC) serogroups. These represented 40.0% of the isolates. The 20 of 57 isolates tested had plasmids and in dot blot hybridization, nine isolates were positive for an EaeA probe and an EPEC adherence factor (EAF) probe while two isolates were negative for EaeA probe but positive for the EAF probe. The nine isolates were characterized as attaching and effacing (A/E) E. coli (AEEC) isolates. 相似文献
15.
Yuste M De La Fuente R Ruiz-Santa-Quiteria JA Cid D Orden JA 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2006,53(2):75-77
A total of 206 attaching and effacing Escherichia coli strains from ruminants were analysed for the presence of the astA (EAST1) and bfpA genes. None of these strains was bfpA-positive. The percentage of enteropathogenic E. coli (EPEC) strains astA-positive found in healthy cattle (15.6%) suggests that this animal species may be a significant reservoir of atypical EPEC potentially pathogenic for humans. 相似文献
16.
Serobiotypes and virulence genes of Escherichia coli strains isolated from diarrheic and healthy rabbits in Brazil 总被引：5，自引：0，他引：5
Penteado AS Ugrinovich LA Blanco J Blanco M Blanco JE Mora A Andrade JR Corrêa SS Pestana de Castro AF 《Veterinary microbiology》2002,89(1):41-51
A total of 178 Escherichia coli isolates from diarrheic and healthy rabbits in the S?o Paulo State (Brazil) were serobiotyped and investigated by PCR for the presence of virulence genes. Among the 90 (50.6%) isolates which possessed the eae gene, 74 were from diarrheic animals and all but one encoded intimin beta. Sixty five (72.2%) of the eae+ isolates had insertion of the locus of enterocyte effacement locus in the pheU locus, 11 (12.2%) in the selC and 14 (15.6%) did not insert in either of these loci. All isolates were negative for genes of the E. coli enterotoxins, Stx1, Stx2, CNF1, CNF2 and EHEC hemolysin. The O132:H2 serotype was dominant, being present in 63 isolates (70%) of the 90 eae+ isolates, and 57 of the 63 isolates of this serotype belonged to biotype 30. PCR detected the gene for AF/R2 fimbriae in 75 (83.3%) of the 90 eae+ isolates. Adherence to HeLa cells was best detected following 6h incubation and a positive fluorescence actin staining (FAS) test was given by 52 isolates. These data show that isolates of E. coli associated with diarrhea in rabbits in Brazil possess the genotype and phenotype typically associated with rabbit enteropathogenic E. coli (EPEC). We conclude that EPEC that possess the eae gene are a common cause of diarrhea in Brazilian rabbit farms and that the pathogenic eae+ AF/R2+ isolates of O132:H2:B30 serobiotype are especially predominant. 相似文献
17.
DNA-DNA hybridization, cultured cell lines, and transmission electron microscopy were used to study pathogenicity traits of 64 Escherichia coli isolated from apparently healthy chickens from 18 small-scale farms in Thika District, Kenya. A total of 39 (60.9%) isolates hybridized with the eae gene probe for enteropathogenic E. coli (EPEC) whereas another 16 (25%) hybridized with the lt and st gene probes and were categorized as enterotoxigenic E. coli. Electron microscopic examination of the eae probe-positive E. coli cultures with the HT-2919A cell line confirmed that they were able to attach intimately and produced effacement typical of EPEC. In addition, negative stain electron microscopy showed that the EPEC strains produced pili that have previously been associated with increased virulence of E. coli infections in chickens. This study has also demonstrated that apparently healthy chickens may carry enteropathogenic E. coli strains. 相似文献
18.
B.A. Hales J.N. Fletcher G. Ridha R.M. Batt C.A. Hart J.R. Saunders 《Research in veterinary science》1991,50(3):9-357
Seventeen bovine and 56 porcine Escherichia coli isolates from cases of diarrhoea and from healthy animals were examined for DNA sequences homologous to the genes for verocytotoxins (VT), enterotoxins and human enterohaemorrhagic E coli/enteropathogenic E coli (EHEC EPEC) sequences. VT-1 was the most common toxin among the bovine isolates and VT-2 the most common in the porcine isolates. No isolates had homologous sequences to enteropathogenic adherence factor, but 71.2 per cent hybridised to the DNA probe encoding specific EHEC sequences, and 95.9 per cent showed homology with a 23 kb DNA fragment common to EHEC and EPEC plasmids. 相似文献
19.
Wani SA Hussain I Fayaz I Mir MA Nishikawa Y 《Veterinary journal (London, England : 1997)》2009,182(3):489-490
Seventy-five Escherichia coli isolates with at least one targeted virulence gene were recovered from 338 lambs with (n=230) and without (n=108) diarrhoea. The isolates belonged to 36 different serogroups. Shiga toxin-producing E. coli (STEC) was isolated from 9.6% of lambs with and 24.1% of lambs without diarrhoea. Enteropathogenic E. coli (EPEC) was isolated from 6.1% of lambs with and 11.1% of lambs without diarrhoea. Of 26 EPEC isolates, seven were typical (positive for bfpA), and, of 34 stx(1) positive isolates, 25 were subtyped as stx(1c). Five of 29 stx(2) positive isolates were subtyped as stx(2d) and two as stx(2c). Seven of 45 eae positive isolates were subtyped as eae subtype zeta (eaezeta). This appears to be the first report of the isolation of typical EPEC from sheep in India. 相似文献