抗菌药物对金双歧去除定植于肠道产ESBLs大肠埃希菌效果的影响研究

目的研究抗菌药物对金双歧去除肠道产ESBLs大肠埃希菌定植效果的影响,为临床合理利用金双歧辅助治疗提供依据。方法选取崇州市人民医院2013年1月至2013年6月开展的＂金双歧去除肠道产ESBLs大肠埃希菌定植的临床研究＂科研项目中试验组患者102例,分成静脉使用抗菌药物组和未使用抗菌药物组,两组患者口服金双歧进行肠道内去定植。结果静脉使用抗菌药物组金双歧去除定植于肠道产ESBLs大肠埃希菌的去除率为30.30%;未使用抗菌药物组金双歧去除定植于肠道产ESBLs大肠埃希菌的去除率为41.67%。两组差异具有统计学意义（χ2=7.61,P〈0.01）。结论抗菌药物对金双歧具有抑制和杀灭作用,使金双歧去除定植于肠道的产ESBLs大肠埃希菌能力减弱或消失。     

ICU患者肠道定植产ESBLs大肠埃希菌基因同源性研究

目的研究ICU患者肠道定植产ESBLs大肠埃希菌基因的同源性,为制定控制多重耐菌医院感染措施提供流行病学和分子生物学依据。方法对ICU患者肛拭子分离出的80株产ESBLs大肠埃希菌做药敏试验,对药敏结果表型完全相同的分成组,对筛选出的药敏表型完全相同的菌株采用Diversilab自动化重复序列（REP）-PCR（repetitive—element sequence—basedPCR）分型系统,分析肠道定植产ESBLs大肠埃希菌基因的同源性。结果80株菌株中有56株未找到药敏结果相同的菌株,未做基因同源性检测;有7组2株药敏表型结果完全相同,有2组3株药敏表型结果完全相同,有1组4株药敏表型结果完全相同,10组药敏表型结果完全相同的菌株做基因同源性检测;7组2株药敏表型结果完全相同只有1组基因有同源性,2组3株药敏表型结果完全相同只有1组中的2株基因有同源性,1组4株药敏表型结果完全相同基因无同源性。5株来源于不同组别药敏表型结果不完全相同的菌株基因具有同源性;具有同源性的菌株患者分别来源于不同时间和不同地点的患者。结论肠道定植产ESBLs大肠埃希菌大部分药敏结果不完全相同;药敏结果完全相同的菌株基因不一定有同源性,药敏结果不完全相同的菌株基因少部分有同源性。     

2010至2011年我院产ESBLs大肠埃希菌的耐药性分析

分析2010年1月至2011年12月牡丹江医学院附属红旗医院临床分离的大肠埃希菌的耐药性变化,为指导临床合理用药提供依据。2010至2011年临床各科室送检的全部标本(包括血、尿、便、痰、分泌物等),采用微生物分析仪进行分离鉴定及药物敏感性分析。2010和2011年产ESBLs大肠埃希菌检出率分别为23.8%5、7.4%,呈上升趋势。产ESBLs大肠埃希菌对大多数抗菌药物的耐药率明显高于非产ESBLs大肠埃希菌(P<0.05)。产ESBLs大肠埃希菌检出率越来越高,耐药率日益严重,给临床抗菌治疗带来很大困难,开展产ESBLs大肠埃希菌耐药性分析,指导临床合理应用抗生素,对控制大肠埃希菌对抗菌药物的耐药性增长有重大意义。     

福建医科大学生肠道中产超广谱β-内酰胺酶大肠埃希菌的定植状况

【摘 要】 目的 分析福建医科大学生肠道中产超广谱β-内酰胺酶（ESBLs）大肠埃希菌（E.coli）的定植状况。方法 2011年9月随机招募福建医科大学生92名,每人收集一份粪便标本并接种于ChromID ESBLs产色培养基筛查ESBLs 阳性E.coli;PCR扩增常见β-内酰胺类基因（SHV、TEM、CTX-M-1组、CTX-M-2组和CTX-M-9组）并且每种基因型随机挑选5株进行测序;同时进行E.coli系统发育分型分析。结果 92份粪便标本筛查出76株ESBLs阳性E.coli,阳性率为82.61%（76/92）;基因扩增显示ESBLs 阳性E.coli中CTX-M-9组58株（76.32%）、TEM型45株（59.21%）、CTX-M-1组27株（35.53%）和SHV型1株（1.32%）;经随机挑选5株测序CTX-M-9组5株均为CTX-M-14基因型,TEM均为TEM-1基因型,CTX-M-1组均为CTX-M-15基因型,SHV为SHV-12基因型;系统发育分型检出A型41株（53.95%）,D型29株（38.16%）,B2型4株（5.26%）,B1型2株（2.63%）。结论 福建医科大学生ESBLs阳性 E.coli定植状况相当严峻,且主要以CTX-M-9组（CTX-M-14基因型）为主。     

儿童泌尿系感染大肠埃希菌的耐药性分析

目的 了解大肠埃希菌在儿童中的感染情况及其耐药性.方法 对中段尿标本进行分离培养及鉴定,药敏试验用K-B法,检测ESBLs用表型确证试验,药敏结果分析用WHONET 5.5软件,统计分析采用x2检验.结果 2009年1月至2011年12月从儿科门诊和病房送检的1755份中段尿标本中共检出85株大肠埃希菌,检出率为4.8％,男女比为6:11; ＜3岁的婴幼儿组57例,占67.1％;3～6岁育龄前儿童17例,占20.0％;＞6岁儿童11例,占12.9％;产ESBLs的大肠埃希菌占60.0％;85株大肠埃希菌对亚胺培南和美罗培南全部敏感,对头孢哌酮/舒巴坦、哌拉西林/他唑巴坦和阿米卡星的敏感率均为90％以上,产ESBLs的大肠埃希菌对氨苄西林、头孢唑啉、头孢他啶、头孢曲松、头孢吡肟、头孢西丁、头孢呋新酯、左旋氧氟沙星和罗红霉素的耐药率较非产ESBLs菌株的耐药率高,P值均＜0.05,差异有统计学意义.结论 儿童泌尿系感染大肠埃希菌,可以选用的抗菌素已极为有限,临床要谨慎用药,并及时根据药敏结果修正药物种类.     

产ESBLs大肠埃希菌的AmpC基因型分析

目的 了解深圳市人民医院产超广谱β-内酰胺酶(ESBLs)大肠埃希菌合并产AmpC酶的状况及基因型特点.方法 从近几年深圳市人民医院产ESBLs大肠埃希菌临床菌株中,筛选出对头孢西丁耐药菌株51株,PCR分别扩增菌株的TEM、SHV、CTX-M基因,同时应用多重PCR检测菌株的AmpC酶基因,序列测定PCR阳性产物以确定其基因亚型.结果 51株菌中有49株至少检出一种ESBLs或AmpC基因.单ESBLs基因阳性菌株37株(72.5％),单AmpC基因阳性4株(7.8％),合并ESBLs和AmpC基因阳性的8株(15.6％).共有41株(80.4％)含CTX-M-14基因,4株含CTX-M-15,其他基因型ESBLs较少.2株检出两种ESBLs基因;一株同时检三种ESBLs基因.检出AmpC基因的菌株12株,其中10株为DHA-1型,2株为CMY-2型;其中6株DHA-1型及2株CMY-2型菌同时检出CTX-M-14基因.结论 该院头孢西丁耐药产ESBLs大肠埃希菌中大多数为单产ESBLs菌,主要为CTX-M-14型;少数同时产生ESBLs和AmpC酶,AmpC酶以DHA-1型为最常见.     

泌尿系感染产ESBLs大肠埃希菌基因分型

目的 了解深圳市人民医院临床泌尿系感染标本中产ESBLs大肠埃希菌的基因型特点.方法 收集近几年深圳市人民医院临床尿液标本中非重复的产ESBLs大肠埃希菌43株,PCR分别扩增菌株的TEM、SHV、CTX-M基因,阳性株进行DNA测序分型.结果 43株产ESBLs大肠埃希菌中40株CTX-M基因阳性,分别为CTX-M-14型36株,CTX-M-9型2株,CTX-M-15型2株,其中17株CTX-M-14型菌株检出TEM-1基因;所有菌株均未检出SHV基因.结论 本地区致泌尿系感染产ESBLs大肠埃希菌中,CTX-M-14型为主.     

新生儿病区产ESBLs大肠埃希菌整合子及其耐药性分析

目的 了解新生儿病区产ESBLs大肠埃希菌整合子的携带情况及其耐药性.方法 采用K-B琼脂扩散法对56株产ESBLs大肠埃希菌进行药敏试验;应用PCR法检测Ⅰ类、Ⅱ类和Ⅲ类整合子;以肠杆菌科重复序列-聚合酶链式反应(ERIC-PCR)进行基因分型.结果 56株产ESBLs大肠埃希菌的Ⅰ类整合子检出率为60.7％,未检出Ⅱ类和Ⅲ类整合子;菌株对庆大霉素、环丙沙星、左氧氟沙星、复方新诺明、头孢唑林、氨曲南、头孢他啶的耐药率差异有统计学意义(P＜0.05),阳性菌株的耐药率高于阴性菌株;56株大肠埃希菌分为45种基因型.结论 Ⅰ类整合子广泛存在于新生儿病区产ESBLs大肠埃希菌并与其耐药性相关.     

临床产ESBLs大肠埃希菌整合子检测及基因型分析

了解临床分离的产ESBLs大肠埃希菌(ESBLs-producing Escherichia coli,ESBL-EC)中Ⅰ、Ⅱ、Ⅲ类整合子及ESBL-EC基因型的分布。收集2014年1月至12月某三甲医院住院患者分离的大肠埃希菌,经全自动细菌分析系统鉴定并检测其对临床常用抗菌药物的耐药性,双纸片协同试验确定ESBL-EC,采用聚合酶链反应(PCR)对整合子基因和ESBLs基因进行检测。K-B法比较整合子阳性菌株与阴性菌株的耐药率。结果发现,98株临床非重复ESBL-EC对青霉素类、头孢菌素类、喹诺酮类、单环酰胺类和庆大霉素耐药率均大于50%,对妥布霉素耐药率为31.62%,对呋喃妥因、阿莫西林/克拉维酸和阿米卡星较敏感,分别为11.11%、13.4%和6.12%;对碳青霉烯类抗菌素、替加环素和哌拉西林/他唑巴坦敏感率为100%。98株菌中检出47株含Ⅰ类整合子(47.96%),3株含Ⅱ类整合子(3.06%),所有菌株中有1株同时含Ⅰ类和Ⅱ类整合子,未检出Ⅲ类整合子。整合子阳性菌株对四环素和复方新诺明的耐药率高于整合子阴性菌株(P0.05)。98株菌中β-内酰胺酶基因TEM、CTX-M-9、CTX-M-1、CTX-M-2和SHV阳性率分别为62.24%、53.06%、32.65%、4.08%和3.06%,ESBL-EC基因分型分布以TEM合并CTX-M-9型(共30株)最多见,占30.61%。结果表明,Ⅰ类整合子在产ESBLs大肠埃希菌中分布广泛,本研究尚不足以证明整合子的存在可影响ESBL-EC菌株抗生素耐药水平。同时携带TEM和CTX-M-9基因是安徽医科大学解放军174临床学院产ESBLs大肠埃希菌临床耐药菌株产生的主要原因。     

产ESBLs大肠埃希菌和肺炎克雷伯菌的检测结果分析

目的 了解产超广谱β-内酰胺酶(ESBLs)大肠埃希菌(ECO)和肺炎克雷伯菌(KPN)的临床分布及耐药性,为临床合理用药提供依据.方法 采用VITEK-2全自动微生物鉴定/药敏分析系统对细菌进行菌株鉴定及药敏分析,对产ESBLs的ECO和KPN的临床分布与耐药结果用WHONET 5.4软件进行统计分析,应用SPSS 11.5软件进行卡方检验.结果 1955株菌中共检出产ESBLs菌916株,检出率为46.9％,其中EC0 570株,检出率为58.9％,KPN 346株,检出率为35.0％,产ESBLs菌主要从痰液和尿液中检出,主要来自ICU、普外科和神经外科;产ESBLs菌对多种抗生素的耐药率明显高于非产ESBLs菌,差异有统计学意义(P＜0.05),对哌拉西林/他唑巴坦、头孢替坦和亚胺培南较敏感.结论 产ESBLs菌株所致的感染以泌尿道感染和呼吸道感染为主,且呈多重耐药性,临床上要重视对产ESBLs菌株的检测和细菌耐药监测,有效控制产ESBLs菌株的产生和流行.     

Bifidobacteria and human health: regulatory effect of indigenous bifidobacteria on Escherichia coli intestinal colonization

Bifidobacteria are assumed to exert colonization resistance to enteric pathogens. We associated C3H germfree mice with either Bifidobacterium longum or Escherichia coli or both strains and studied how they settled in the gut and the lymphoid organs as well as their effect on mucus composition. Within 24 hE. coli colonized the gut of germfree or B. longum ex-germfree mice. In contrast,B. longum was established in the intestine of E. coli ex-germfree mice only 1 month after inoculation whereas it colonized the germfree gut within 24 h. Although B. longum did not exert colonization resistance to E. coli, the establishing of bifidobacteria in the gut partly prevented changes in the E. coli cell wall. After colonization of the germfree or B. longum mono-associated mice, E. coli lipopolysaccharide exhibited a higher concentration of Kdo and the O-antigen side chain disappeared. A reduction in Kdo content was observed within 1 month in E. coli-B. longum diassociated mice whereas it remained at a high level in E. coli mono-associated mice. Association in a second step with B. longum led to Kdo reduction. Changes in E. coli LPS might be related to mucus modification. Inoculation of either bacterium led to a slow increase in mucus protein content which was however twice as high after E. coli implantation. Inoculation of B. longum in a second step led to a reduction in protein content before B. longum colonized the intestine at a high level suggesting that the protein concentration in the mucus was controlled by the host itself. A new glycoprotein of 200-230 kDa detected during the period preceeding colonization seemed to be broken down by B. longum. The resulting end product might participate in the restoration of E. coli LPS. Finally,B. longum inoculation led to the disappearance of E. coli from kidneys, liver, spleen and lung. The organs were cleared of E. coli before B. longum highly colonized the intestine suggesting that high intestinal colonization by B. longum was not required. Regulation of E. coli invasion seemed to depend on the ability of B. longum to stimulate the immune system.     

乳果糖联合金双歧对肝硬化合并自发性腹膜炎患者 肠道微生态及黏膜屏障功能的影响

目的探讨乳果糖联合金双歧对肝硬化合并自发性腹膜炎(SBP)患者肠道微生态及黏膜屏障功能的影响。方法选取2017年5月-2019年5月医院收治的60例肝硬化合并SBP患者,采用信封法将其分为常规组和联合组,各30例。常规组实施常规治疗,联合组在常规组基础上实施乳果糖联合金双歧治疗。采集两组患者粪便样本,采用Illumina Miseq测序平台检测并对比治疗前后两组患者肠道菌群多样性,并应用定量PCR技术检测肠道优势菌群相对量;采用口服糖分子探针乳果糖(LAC)、甘露醇(MAN)法评估治疗前后两组黏膜屏障功能的变化。结果治疗前两组多样性(Shannon)指数和丰富度(Chao)指数比较差异无统计学意义(均P0.05),治疗后联合组Shannon和Chao指数均高于常规组(均P0.05);治疗后联合组Shannon指数、Chao指数均高于治疗前(均P0.05),而常规组无变化(均P0.05)。治疗前2组乳杆菌、双歧杆菌、肠杆菌相对数量比较差异均无统计学意义(均P0.05),治疗后联合组双歧杆菌相对数量高于常规组(P0.05),肠杆菌相对数量低于常规组(P0.05),乳杆菌相对数量无变化(P0.05);与治疗前比较,治疗后联合组双歧杆菌相对数量增加(P0.05),肠杆菌减少(P0.05),乳杆菌无变化(P0.05);治疗前后常规组肠道优势菌群数量均无变化(均P0.05)。治疗前两组LAC、MAN排泄率及LAC/MAN比较差异均无统计学意义(均P0.05),治疗后联合组LAC排泄率、LAC/MAN均低于常规组(均P0.05),MAN排泄率高于常规组(P0.05);与治疗前比较,治疗后两组LAC排泄率、LAC/MAN均降低(均P0.05),联合组MAN排泄率升高(P0.05),常规组MAN排泄率无变化(P0.05)。两组临床疗效等级分布比较差异有统计学意义(P0.05),且联合组总有效率高于常规组(P0.05)。结论乳果糖联合金双歧辅助治疗肝硬化合并SBP,有助于调节肠道菌群,改善黏膜屏障功能。     

产ESBL克雷伯菌与大肠埃希菌质粒分布的初步研究

比较产超广谱 β 内酰胺酶克雷伯菌与大肠埃希菌质粒的表型与分布。用BlaTEM引物经PCR技术将 5 1株克雷伯菌与 2 9株大肠埃希菌编码产超广谱 β 内酰胺酶的质粒扩增 ,琼脂糖凝胶电泳分离目的片段后得到完整的质粒电泳图谱。克雷伯菌与大肠埃希菌存在有相同大小的产超广谱 β 内酰胺酶的质粒。 2种细菌有产ESBL相同质粒 ,PCR技术可用于产超广谱 β 内酰胺酶细菌质粒的分析。     

产超广谱β-内酰胺酶大肠埃希菌和肺炎克雷伯菌blaCTX-M基因的检测

目的了解产CTX-M型超广谱β-内酰胺酶 (ESBLs) 大肠埃希菌和肺炎克雷伯菌在深圳市人民医院的分布情况.方法应用美国国家临床实验室标准化委员会(NCCLS)推荐的表型确证试验,从2000年6月～2003年8月该院临床标本分离株中筛选出不重复的产ESBLs菌株215株,其中大肠埃希菌151株,肺炎克雷伯菌64株,应用聚合酶链反应(PCR)检测所有产ESBLs株的bla(CTX-M)基因.结果 PCR结果显示,大肠埃希菌bla(CTX-M)基因阳性率为92.1%(139/151),肺炎克雷伯菌的阳性率为65.6%(42/64).bla(CTX-M)基因阳性菌株主要来源于临床送检尿和痰标本,并广泛分布于20多个临床科室.结论该院临床分离的大肠埃希菌和肺炎克雷伯菌产生的ESBL大多数为CTX-M型,该类酶广泛分布于各临床科室,需引起重视.     

Transcriptional regulation through RfaH contributes to intestinal colonization by Escherichia coli

The Escherichia coli regulatory protein RfaH contributes to efficient colonization of the mouse gut. Extraintestinal pathogenic (ExPEC) as well as non-pathogenic probiotic E. coli strains rapidly outcompeted their isogenic rfaH mutants following oral mixed infections. LPS-core and O-antigen side-chain as well as capsular polysaccharide synthesis are among the E. coli virulence factors affected by RfaH. In respect of colonization, deep-rough LPS mutants (waaG) but not capsular (kps) mutants were shown to behave similarly to rfaH mutants. Furthermore, alteration in the length of O-antigen side-chains did not modify colonization ability either indicating that it was the regulatory effect of RfaH on LPS-core synthesis, which affected intestinal colonization. Loss of RfaH did not significantly influence adhesion of bacteria to cultured colon epithelial cells. Increased susceptibility of rfaH mutants to bile salts, on the other hand, suggested that impaired in vivo survival could be responsible for the reduced colonization capacity.     

Inhibitory effect of penicillin on proline synthesis in Escherichia coli

The production of glutamic gamma-semialdehyde, an intermediate in the synthesis of proline, was inhibited in Escherichia coli by physiological concentrations of penicillin. Sucrose (0.6 m) and sodium chloride (0.1 m) prevented penicillin inhibition of glutamic gamma-semialdehyde synthesis. Cells which were in the stationary phase, or which had been permitted to metabolize without growth, were insensitive to the effects of penicillin on glutamic gamma-semialdehyde synthesis.     

Escherichia coli Nissle 1917 for probiotic use in piglets: evidence for intestinal colonization

Aims:  This study was prompted to investigate the intestinal localization and colonization of orally administered Escherichia coli Nissle 1917 (EcN) in piglets.
Methods and Results:  EcN was fed to ten EcN-negative piglets (3 months) over seven consecutive days. Faecal samples were collected repeatedly and tested for EcN-DNA by a combined culture/PCR assay and for viable EcN by culture methods, respectively. EcN-DNA was detectable in faeces of all piglets within the first 24 h after it was added to the feed. After the administration of EcN had been stopped, the presence of EcN-DNA in faecal samples indicated that all piglets shedded EcN with their faeces intermittently through up to 33 days. In addition, E. coli strains indistinguishable from EcN by all markers tested (rdar colony morphotype, multiplex PCR and GEI II-PCR analyses, Xba I-pattern, K5 phage susceptibility) were isolated from faecal samples and from mucosal swabs taken at euthanasia at the end of the experiment.
Conclusions:  EcN colonizes the intestine and persists in conventionally reared piglets for at least 4 weeks upon oral administration.
Significance and Impact of the Study:  Results of this study have implications for efficacy and safety assessments of EcN as a probiotic strain for use in pigs.