共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
致病性大肠杆菌包括肠致病性大肠杆菌(intestinal pathogenic Escherichia coli, IPEC)和肠外致病性大肠杆菌(extraintestinalpathogenicE.coli,ExPEC),可引起人和动物多种感染性疾病。ExPEC主要在肠道外其他组织脏器定殖并导致感染,包括尿道致病性大肠杆菌(uropathogenicE.coli, UPEC)、新生儿脑膜炎大肠杆菌(newborn meningitis E. coli, NMEC)和禽致病性大肠杆菌(avian pathogenic E. coli, APEC)。人源ExPEC (UPEC和NMEC)主要引起人尿道感染、肾盂肾炎和新生儿脑膜炎,而APEC可导致禽类的大肠杆菌病,造成家禽业的巨大经济损失。另外,乳腺致病性大肠杆菌(mammary pathogenic E. coli, MPEC)和猪源ExPEC可导致奶牛乳房炎、猪的肺炎及急性败血症等病症。研究发现,ExPEC类菌株在基因组结构上很相似,与IPEC本质区别在于致病机制不同,ExPEC具有很多相同的毒力基因和耐药基因,而且动物源ExPEC... 相似文献
4.
对人尿道致病性大肠杆菌(uropathogenic Escherichia coli,UPEC)HEC4株和禽致病性大肠杆菌(avian pathogen-ic Escherichia coli,APEC)E058株进行毒力基因和其他相关特性的比较,结果显示,它们具有一些共同的毒力基因,包括一些存在于APEC中一个大的可传递质粒上的基因;同时,它们也具有一些相似的生化特性。对SPF鸡的致病性试验显示,这两株分离株具有相似的致病力。因此,对于APEC和UPEC的相关性,以及APEC是否有可能导致人尿道感染或者成为UPEC的毒力基因贮主,有待进一步研究。 相似文献
6.
[目的]检测禽致病性大肠杆菌IMT5155自分泌黏附素基因等具有代表性的疑似毒力基因在不同来源大肠杆菌中的分布,为进一步研究其致病机理提供依据.[方法]采用PCR和Dot blot,检测疑似毒力基因在不同地区(101株大肠杆菌中国分离株和121株大肠杆菌德国分离株)、不同来源(人源、禽源及猪源)大肠杆菌中的分布,并分析其和大肠杆菌系统进化分群的关系.[结果]自分泌黏附素基因B11等11个疑似毒力基因在禽致病性大肠杆菌中分布率较高,阳性率分别为:A1 36.4%(32/88)、A8 53.4%(47/88)、A1063.6%(56/88)、B1137.5%(33/88)、F3 59.1%(52/88)等,且疑似毒力基因主要存在于大肠杆菌B2进化群中.值得注意的是,D1、E9和F11基因片段在新生儿脑膜炎大肠杆菌中有较高的分布率,分别为60%(6/10)、80%(8/10)和90%(9/10),而在新生儿脑膜炎大肠杆菌中未检测到B11基因.[结论]自分泌黏附素B11等疑似毒力基因与禽致病性大肠杆菌关系密切,但疑似毒力基因D1、E9和F11与新生儿脑膜炎大肠杆菌密切相关,提示禽致病性大肠杆菌可能是新生儿脑膜炎大肠杆菌的毒力基因储库. 相似文献
7.
为调查林麝肺源致病性大肠杆菌O因子血清型以及相关耐药基因的流行状况,本试验采用玻板凝集反应法进行O因子血清型鉴定;同时用PCR方法检测耐药基因。结果显示:O血清型定型的有16株菌,分别属于9个不同的血清型,其中O78为优势血清型,占定型菌株的43.75%(7/16)。同时,29株菌皆携带多种耐药基因,其中磺胺类耐药基因sul1、sul2、sul3,喹诺酮类耐药基因aac(6')-Ib、qnrB,β-内酰胺酶类耐药基因blaTEM、blaCTX-M,氨基糖苷类耐药基因aac(3)-IIa、ant(3″)-Ia和四环素类耐药基因tet(B)检出率较高,检出率分别为100%、96.55%、96.55%、100%、86.21%、100%、65.52%、100%、96.55%和58.62%。本试验结果对林麝临床科学合理用药有重要指导意义。 相似文献
8.
9.
摘 要:[背景]近年来,我国规模猪场着重加强了对猪繁殖与呼吸综合征、猪圆环病毒病、猪瘟、猪伪狂犬病、猪链球菌病、副猪嗜血杆菌病等疫病的防控,却忽视了由肠外致病性大肠杆菌(Extraintestinal Pathogenic Escherichia coli,ExPEC)对猪群健康产生的潜在危害性,了解和掌握猪源ExPEC流行特征意义显著。[目的]探究临床分离的54株猪源ExPEC血清型、系统进化群和基因型的分布及流行特征。[方法]应用玻板凝集试验和试管凝集试验鉴定O抗原血清型,采用PCR技术检测系统进化群鉴定相关基因、28个ExPEC相关毒力基因以及多位点序列分型相关基因。[结果]受试菌中有52株确定了O抗原血清型,其中40株为O38 (74.1%),为优势血清型;8株为O127 (14.8%),O93和O11均2株(各占3.7%)。受试菌中44株为B2群(81.5%),是主要系统进化群,D群和B1群均5 株(各占 9.3%);28 个 ExPEC 相关毒力基因中ompA、ibeA、fimH、traT、focD、papA、iroN、iutA、iucD、cvaC、tsh、kpsMT Ⅱ、iss和ompT出现的频率超过50%,其中ompA和ibeA检出率分别达100%和96.3%,为高度流行的毒力基因,未检到cnf1,而bmaE、malX和iha更倾向分布于D群菌株中。受试菌共呈现31种ST型,其中ST10和ST648均5株(各占9.3%),ST410和ST101均4株(各占7.4%)。[结论]猪源ExPEC优势血清型及系统进化群在不同地区、不同时段上的流行分布均存在一定差异,呈现动态过程,O38作为优势血清型目前尚未见报道,具有高致病性的B2群和D群菌株有逐渐增多的趋势。ST型复杂多样,呈现遗传多样性,在一定程度上与人源和禽源ExPEC具有相同的遗传背景。 相似文献
10.
从临床疑似大肠杆菌感染的病禽组织中分离到69株细菌(其中鹅源29株,鸡源40株);通过常规形态学、培养特性和生化特征的研究,确定为大肠杆菌。PCR检测表明,其中46株(66.7%)为F1 大肠杆菌,10株(14.5%)为F1 HPI 大肠杆菌,2株(2.9%)为HPI 大肠杆菌;通过比较还发现,F1菌毛和HPI在鹅源和鸡源大肠杆菌中以及不同脏器来源的菌株中具有相似的分子流行病学。O抗原鉴定结果表明鹅源大肠杆菌的O抗原型主要有O26、O78、O18、O117,鸡源大肠杆菌的O抗原型主要有O109、O24、O18、O139、O78。药敏试验表明,其中绝大多数菌株对先锋霉素V、呋喃妥因、庆大霉素敏感,对环丙沙星因菌株差异而不同,林可霉素、四环素、多粘菌素多不敏感。 相似文献
11.
Mutator phenotype confers advantage in Escherichia coli chronic urinary tract infection pathogenesis
Labat F Pradillon O Garry L Peuchmaur M Fantin B Denamur E 《FEMS immunology and medical microbiology》2005,44(3):317-321
It has been suggested that mutator phenotype could be associated with an increase in virulence, but to date experimental evidences are lacking. Epidemiological studies have revealed that urinary tract infection isolates encompass the highest proportion of mutator strains within the Escherichia coli species. Using the uropathogenic strain CFT073 and its mutS- mutator mutant, we show that the mutator strain is selected in vitro in urine and in the late stages of infection in a mouse model having urinary tract infection. Thus, we report that, under specific conditions, i.e., urinary tract infection, the mutator phenotype may confer an advantage in pathogenesis. 相似文献
12.
目的 调查肺结核合并下呼吸道大肠埃希菌感染患者的临床特点及其病原菌对常用抗菌药物的耐药性,为临床诊疗提供参考依据。方法 回顾性分析2011年1月至2015年8月共109例肺结核患者合并下呼吸道感染病例,按照《全国临床检验操作规程》第3版操作流程分离鉴定,K-B纸片扩散法进行药敏试验。结果 检出大肠埃希菌的标本主要为痰液(88.07%)。药敏检测提示,大肠埃希菌对阿米卡星、亚胺培南、哌拉西林/他唑巴坦、美罗培南、奈替米星、妥布霉素和头孢哌酮/舒巴坦较敏感,耐药率均<20%,可作为临床治疗该菌感染的首选抗菌药物。结论 大肠埃希菌是导致肺结核患者下呼吸道感染常见致病菌之一,其耐药性较高,应引起人们的高度关注。同时应提高临床样本的送检率,根据药敏检测结果合理选用抗菌药物。 相似文献
13.
Jan M. Prins Constance Schultsz Peter Speelman Sander J.H. van Deventer 《FEMS immunology and medical microbiology》1996,16(3-4):283-289
Abstract We measured urinary endotoxin, IL-6 and IL-8 levels in 23 patients with gram-negative urosepsis. The endotoxin and cytokine levels showed a 100–1000 fold range. No correlation was found between levels of urinary endotoxin, and IL-6 or IL-8 levels. In all cases bacterial numbers were ≥ 105 CFU ml−1 urine. The endotoxin content of the isolated microorganisms neither correlated with the urinary cytokine levels, nor with IL-6 and IL-8 levels obtained in vitro when 103 log-phase CFU of each of the bacteria were incubated with heparinized whole blood of three healthy donors. Neither the haemolysin phenotype of the bacteria, nor the presence of the P-pili gene was correlated with the cytokine response in vivo or in vitro. Other factors than known bacterial virulence factors apparently contribute to the wide variation in urinary cytokine levels in urinary tract infection. 相似文献
14.
呼吸道感染病原菌分析 总被引:7,自引:0,他引:7
王佩芬 《中国微生态学杂志》2000,12(6):349-350
目的 了解老年人院内呼吸道感染与非老年人呼吸道感染病原菌分布情况。方法 回顾性调查1998年1月至12月老年人院内呼吸道感染(老年组)的285份痰标本和同时期非老年人呼吸道感染(非老年组,含门诊和住院)的1192份痰标本的培养情况。结果 老年组阳性率为89.1%(254/285),其中22份标本为混合感染,共检出病原菌276株,以非发酵菌占绝对优势(97.8%);非老年组阳性率为40.3%(480/1192),病原菌无明显集中趋势,非发酵菌28.3%,肠杆菌科23.8%,革兰阳性菌25.0%,真菌22.9%。结论 老年组阳性率明显高于非老年组(X^2=219.6,P〈0.005),病原菌以非发酵菌为主,非老年组病原菌各科细菌所占比例无明显差异,引起呼吸道感染的病原菌主要为条件致病菌。 相似文献
15.
Jane L Pearcea Richard K.J Lukea Karl A Bettelheima 《FEMS immunology and medical microbiology》1999,25(1-2):137-144
This investigation is an extension of previous studies on the possible role of intestinal Escherichia coli in sudden infant death syndrome (SIDS) to include the isolation of extraintestinal E. coli. The lungs of 52 and the blood of 144 SIDS infants were cultured and isolates were investigated. E. coli was isolated from about a quarter of post-mortem lung samples and about 15% of blood samples from SIDS infants. The isolates were subjected to microbiological studies, including serotyping and haemolysin assays. The majority were found to belong to serogroups commonly associated with bacteraemia. These results may indicate that extraintestinal E. coli plays a role in SIDS. 相似文献
16.
[背景]猪源肠外致病性大肠埃希氏菌(extraintestinal pathogenic Escherichia coli,ExPEc)是一种严重危害养猪业的病原菌,有关其生物膜形成能力与耐药性的研究报道很少。[目的]探讨从病猪肺脏中分离鉴定的3株ExPEc的生物膜形成能力及耐药性,为从抗生物膜形成角度防治猪肠外大肠埃希氏菌病提供参考。[方法]采用96孔板结晶紫染色法结合正交实验优化猪源ExPEc分离株的生物膜形成最佳条件与成膜能力;通过扫描电镜观察各菌株生物膜的形态结构;利用PCR方法检测其携带的生物膜形成相关基因;采用微量肉汤稀释法测定抗生素对生物膜态与浮游态下猪源ExPEc分离株的最小抑菌浓度(minimum inhibitory concentration,MIC)。[结果]3株猪源ExPEc的最佳成膜条件并不一致,但在各自最佳条件下均能形成很强的生物被膜且同时携带10个生物膜形成相关基因(pgaA,pgaB,pgaC,pgaD,luxS,fimA,hipA,iha,flhC,flhD)。扫描电镜观察显示,菌株SE-1聚集后可形成片状生物膜,菌株SE-2和SE-3聚集后可形成多... 相似文献
17.
【目的】构建禽致病性大肠杆菌(Avian pathogenic Escherichia coli,APEC)VI型分泌系统2(Type VI secretion system 2,T6SS2)结构基因vgrG缺失株,研究其对APEC生物学特性及致病性的影响。【方法】通过Red同源重组方法构建DE719菌株vgrG基因缺失株,并利用低拷贝质粒pSTV28构建互补株。比较分析野生株、缺失株与互补株的生长特性、运动性、生物被膜形成能力、黏附侵袭能力、动物致病力等差异。【结果】vgr G基因缺失不影响DE719的生长速度、运动能力及生物被膜形成能力。致病性试验表明缺失vgrG导致体内定殖能力及致病力显著下降,然而对DF-1细胞的黏附能力增强。【结论】T6SS2核心组分VgrG在APEC感染过程中发挥重要作用,为了解APEC的致病作用提供参考。 相似文献
18.
The presence of the genes for Escherichia coli adherence factor (EAF), attaching and effacing lesion (eae) and bundle-forming pili (bfp) in 72 strains identified as enteropathogenic E. coli (EPEC) by slide agglutination was evaluated using hybridization and PCR. The adherence property of these strains was assayed using 3h HeLa cells adherence assay. The results obtained indicated that virulence-associated genes were present in 65% of the strains but only ten (13.9%) isolates were positive for all the three markers (typical EPEC), 37 (51.4%) isolates carried either one or two of these determinants (atypical EPEC) and the remaining 25 (34.7%) were negative for all these genes. In vitro adherence assay showed that 44 (61.1%) strains adhered to HeLa cells with a defined pattern, 13 (18.1%) isolates adhered loosely with no definite pattern and the remaining 15 (20.8%) were non-adherent. Analysis of the results showed a statistically significant association between the presence of the virulence-related genes with adherence of the strains with a defined pattern (P=0.0001). These results indicated that since over 60% of the strains identified by serogrouping carried at least one of the putative virulence markers, it therefore seems that this simple test is still of value in our setting although the need for a confirmatory test is also indicated. 相似文献
19.
目的分析女性患者泌尿系统感染大肠埃希菌的耐药性,为临床合理使用抗生素提供依据。方法采用全自动微生物鉴定系统对女性泌尿系统感染患者分离出的病原菌进行鉴定和药敏分析。结果大肠埃希菌非产ESBLs株对氨苄西林、第一、二代头孢菌素类药品高度耐药。大肠埃希菌非产ESBLs株对碳青霉烯类药物美罗培南无耐药,对第三代头孢菌素敏感率高,耐药率低。产ESBLs大肠埃希菌,仅碳青霉烯类抗生素美罗培南敏感。结论女性泌尿系统感染大肠埃希菌的多重耐药性日趋严重,需加强对抗生素使用的规范化管理,合理使用抗菌药物,控制耐药菌的传播和流行。 相似文献
20.
Bernard Chinaa Frédéric Goffauxa Vinciane Pirsona Jacques Mainila 《FEMS microbiology letters》1999,178(1):177-182
Attaching and effacing Escherichia coli (AEEC) virulence genes include the eae, the tir, the espA and the espB genes. These genes have been sequenced from several AEEC strains. The sequences alignments revealed the presence of constant and variable regions. Multiplex polymerase chain reactions were developed, in order to determine the subtype of each gene present in a particular isolate. AEEC strains isolated from calves dead of diarrhea, from healthy calves and from infected humans were compared. The same pathotypes were found in sick and healthy calves but in inverted proportion. These pathotypes were also found in human AEEC. Although, the human EHEC strains from serotype O157 possessed their own pathotype. 相似文献