Identification of Shiga- like toxin Escherichia coli isolated from children wi th diarrhea by polymerase chain reaction

目的：探讨产志贺样毒素大肠埃希菌（SLTEC）在小儿腹泻中的病原学地位。方法：根据肠出血性大肠埃希菌（EHEC）0157：H7SLT1、SLT2、eaeA基因片段设计了3对引物,采用PCR法检测大肠埃希菌中SLT1、SLT2、eaeA毒力基因。结果：29株标准致泻大肠埃希菌（EHEC、EPEC、ETEC）和10株其它肠道病原菌中,只有1株EHEC检出SLT1、SLT2、eaeA毒力基因,其它均为阴性。从1032例腹泻患儿粪便中分离的474株未定型大肠埃希菌中,检出SLT1 20株（4.2％）,SLT2 7株（1.5％）;74株产志贺样毒素侵袭性大肠埃希菌（ESIEC）中检出SLT115株（20.3％）,SLT2 5株（6.8％）。结论：SLTEC是太原地区引起小儿腹泻的一种重要的致泻病原菌。     

产毒性和致病性大肠杆菌中小肠结肠炎耶尔森菌强毒力岛的检测

目的　了解小肠结肠炎耶尔森菌强毒力岛在产毒性和致病性大肠杆菌中的分布,探讨毒力岛在大肠杆菌中的结构和功能。方法　对毒力岛的关键基因irp2、fyua和asn-intB进行PCR扩增和DNA测序,并对irp2和fyua进行原位杂交。结果　在检测的93株肠产毒性大肠杆菌和10株肠致病性大肠杆菌基因irp2的检出率分别为32.25％（30/93）和30％（3/10）,fyua的阳性率为21.51％（20/93）和30％（3/10）,而且这些阳性菌株中的毒力岛大部分连接到天门冬氨酸tRNA（asn tRNA）位点。结论　小肠结肠炎耶尔森菌强毒力岛在产毒性和致病性大肠杆菌中较高的阳性率,对于大肠杆菌毒力的变化和毒力的调控以及细菌毒力的进化可能具有重要意义。     

佛山市食品中致泻大肠埃希菌菌型分布及毒力研究

目的 了解佛山市食品中致泻大肠埃希氏菌的菌型分布及毒力携带情况。方法采集佛山市十类食品362件中分离的17株致泻大肠埃希氏菌。按GB4789．6-94国家卫生标准检验方法进行血清分型；用ELISA检测耐热肠毒素(ST)和不耐热肠毒素(LT)；毒力测定采用小鼠致病力试验和采用irp2和irpB基因探针菌落原位杂交检测ES-IEC菌株毒力岛。结果 菌型分布在三类11个型别上，其中EPEC占41．17％(7／17)，EIEC为35．29％(6／17)。ESIEC为23．53％(4／17)；17株致泻大肠埃希氏菌在七类食品中均有存在。对小鼠致病力试验均为阳性；耐热肠毒素(ST)和不耐热肠毒素(LT)均为阴性，其中4株ESIEC中1株携带耶尔森氏菌强毒力岛(HPI)。结论佛山市食品中污染致泻大肠埃希氏菌普遍，对小鼠致病力与耐热和不耐热肠毒素无必然联系；有携带耶尔森氏菌HPI的ESIEC存在。应引起足够重视。     

产毒性和致病性大肠杆菌中小肠结肠炎耶尔森菌强毒力岛的检测

目的 了解小肠结肠炎耶尔森菌强毒力岛在产毒性和致病性大肠杆菌中的分布，探讨毒力岛在大肠杆菌中的结构和功能。方法 对毒力岛的关键基因irp2,fyua和asn-intB进行PCR扩增和DNA测序，并对irp2和fyua进行原位杂交。结果 在检测的93株肠产毒性大肠杆菌的10株肠致病性大肠杆菌基因irp2的检出率分别为32.25%(30/93)和30%（3/10),fyua的阳性率为21.51%(20/93)和30%（3/10）。而且这些阳性菌株中的毒力岛大部分连接到天门冬氨酸tRNA(asntRNA）位点。结论 小肠结肠炎耶尔森菌强毒力岛在产毒性和致病性大肠肝菌中较高的阳性率，对于大肠杆菌毒力的变化和毒力的调控以及细菌毒力的进化可能具有重要意义。     

携带小肠结肠炎耶尔森菌HPI毒力岛大肠杆菌的毒力基因分析

目的探索HPI毒力岛阳性大肠杆菌的毒力基因存在情况。方法使用PER和杂交技术对152株HPI毒力岛阳性的大肠杆菌进行相关毒力基因检测。结果在152株携带HPI毒力岛的大肠杆菌中，基本上未栓出常见的5类致泻性大肠杆菌的毒力基因，但是部分菌株检出泌尿道致病性大肠杆菌PAI毒力岛基因yc73和prrA以及RTX毒力岛基因rtx615。结论这些大肠杆菌和已知的致泻性大肠杆菌有明显不同，携带HPI毒力岛的大肠杆菌可能包括几个不同的群，可能存在其它的尚未发现的毒力因子，有必要继续进行进一步研究。     

西南战区腹泻患者携带耶尔森菌HPI毒力岛大肠艾希菌调查

目的收集西南战区部队和地方医院腹泻患者粪便标本,做细菌分离与鉴定,分析病原菌组成。对分离的部分生化反应符合大肠艾希菌,但血清学证明不属于肠侵袭性大肠杆菌（EIEC）、肠产毒性大肠杆菌（ETEC）、肠致病性大肠杆菌（EPEC）和肠出血性大肠杆菌（EHEC）的菌株,做耶尔森菌HPI毒力岛irp-2基因检测,了解西南战区腹泻病人粪便中分离的大肠艾希菌携带耶尔森菌HPI毒力岛irp-2基因的存在情况。方法常规法分离,用肠杆菌科细菌生化鉴定编码系列（API-20E或GYZ-11e系统）和VITEK32全自动微生物生化分析仪以及弧菌科细菌生化鉴定编码系列（GYZ-9V系统）进行系统鉴定,PCR扩增法检测耶尔森菌HPI毒力岛。结果在1 352例腹泻病人中检出36个属种594株病原菌,检出率为43.93%,弗劳地枸橼酸杆菌检出率为6.14%、肺炎克雷伯菌为5.62%、变形杆菌4.66%、志贺菌4.07%,EIEC 1.85%,检出36株携带耶尔森菌HPI毒力岛irp-2基因大肠艾希菌,检出率为2.66%。结论从1352例腹泻患者粪便标本中分离到弗劳地枸橼酸杆菌占首位,肺炎克雷伯菌次之,变形杆菌、志贺菌分别居第三、第四位。西南战区存在携带耶尔森菌HPI毒力岛irp-2基因的大肠艾希菌。     

产毒性大肠杆菌（ETEC）中毒力岛分布的研究

目的 了解小肠结肠炎耶尔森菌强毒力岛在产毒性大肠杆菌中的分布,以便于进一步深入研究毒力岛在大肠杆菌中的结构的完整性和功能。方法 PCR扩增和原位杂交及基因序列分析,结果 在检测的93株产毒性大肠杆菌（ETEC）的毒力岛的检出率为32.25%(32/93),而且这些阳性菌株中的毒力岛大部分连接到asntRNA(天门冬氨酸tRNA0位点。结论 产毒性大肠杆菌是致病性较强的病原菌之一,而小肠结肠炎耶尔森菌强毒力岛在产毒性大肠杆菌中阳性率较高的分布。对于进一步研究产毒性大肠杆菌的毒力的变化和毒力的调控以及细菌毒力的进化具有重要意义。     

缺失HPI毒力岛的EAggEC O42突变菌株的构建及鉴定

目的构建并鉴定HPI毒力岛缺失的EAggEC突变株.方法运用基因重组方法，以irp8基因部分序列作为同源重组的一侧序列，irp5基因序列作为同源重组的另一侧序列，中间插入有卡那霉素（Km）抗性基因（kan）标记。以pCVD442作为载体，构建含有irp8部分序列和irp5基因的重组自杀质粒pC085。以EAggEC O42为出发菌株．构建缺失irp8-irp5约24kb的HPI毒力岛功能卡受心区区域的全岛缺失侏EAG85．结果通过接合转移和同源重组．利用蔗糖抗性筛选，pC085上的同源序列有效的置换rEAggEC O42的irp8和irp5基凶。PCR方法扩增irp3、ybtA、irp9等基因的结果显示，筛选出的EAG85确为缺失HPI毒力岛基闪的EAggEC菌株结论成功地构建了缺失HPI毒力岛的EAggEC O42突变菌株．为进一步阐明HPI毒力岛存EAggEC菌株中的功能建立了重要的物质基础。     

国内首次发现携带耶尔森菌HPI毒力岛rip^-2也基因的阴沟肠杆菌

目的研究感染性腹泻患者粪便中分离的阴沟肠杆菌携带的小肠结肠炎耶尔森菌HPI毒力岛irp-^2基因，并评价其菌株的毒力和耐药情况。方法PCR扩增法检测毒力岛irp^-2基因，小白鼠腹腔注射法捡测毒力，药敏试验采用K—B纸片扩散法。结果从感染性腹泻患者粪便中分离的9株阴沟肠杆菌均扩增出irp^-2基因片段，其相对分子量与对照菌株小肠结肠炎耶尔森菌WA株（08型）的相应PCR片段一致，并具有较强的毒力。结论检出的阴沟肠杆菌含有小肠结肠炎耶尔森菌HPI毒力岛irp^-2基因且为具有毒力的菌株，与致病性密切相关。     

闽东农村婴幼儿腹泻病原学调查

对闽东农村５８２例婴幼儿腹泻患者进行细菌性病原调查，在２０８例腹泻患儿粪便中检出致泻菌２４６株，检出率为４２．２６％，其中ＥＴＥＣ７７株（１３．２３％），ＥＩＥＣ１９株（３．２６％），空肠弯曲菌１７株（２．９２％），沙门氏茵６株（１．０３％），亲水性气单胞菌２株（０．３４％）。表明致泻大肠杆菌（ＥＴＥＣ，ＥＰＥＣ，ＥＩＥＣ）是我区婴幼儿致泻主导菌群，占检出菌的６６．３％。混合感染率在农村腹泻患儿中高达１７．３％，值得临床工作者重视。     

Study of the identification of enterotoxigenic Escherichia coli by LT-DNA gene hybridization.

Reference strains of enterotoxigenic Escherichia coli (ETEC), non-ETEC, and other enteropathogenic bacteria were used to prove the reliability of LT-DNA gene hybridization. In the test, LT-DNA gene hybridization was compared with plate immunohemolytic test (PIHT) in identifying LT-ETEC. The results obtained by both methods showed no significant differences. 791 strains of E. coli isolated from 1,875 children with acute diarrhea in Taiyuan Children's Hospital were examined for LT-ETEC by LT-DNA gene hybridization and PIHT. 289 strains examined by LT-DNA gene hybridization were LT positive, while 205 strains examined by PIHT were LT positive. Three different assays were done: colony hybridization, PIHT and fecal direct blot hybridization on each of 74 fecal specimens from children with acute diarrhea. It was found that identification of LT-ETEC using fecal direct blot hybridization is a simple, sensitive and more practical method.

     

南宁市致泻性大肠杆菌病原监测与研究

目的：了解南宁市食品及腹泻病人、奶牛致泻性大肠杆菌污染、感染状况。方法：对４６６份各类标本（肉类、奶类、海产品、蔬菜及腹泻者肛拭、奶牛粪便等）进行致泻性大肠杆菌病原分离培养。结果：未检获Ｏ１５７：Ｈ７，检获其他致泻性大肠杆菌１１５株，检出率为２３．１％，其中ＥＰＥＣ３５株（３０．４３％），ＥＩＥＣ１７株（１４．７８％），ＥＴＥＣ２１株（１８．２６％），ＥＳＩＥＣ４２株（３６．５２％）。结论：食品被     

感染性腹泻临床与病原学分布特点及耐药分析

目的探讨新疆地区感染性腹泻的临床及病原学分布特点,指导经验性治疗感染性腹泻,避免滥用抗菌药物。方法回顾性分析2009年8～10月及2010年5～10月新疆医科大学第二附属医院肠道门诊感染性腹泻患者的临床及病原学特点、药敏结果。结果以急性腹泻为首发症状就诊的183例患者中,26例(14.2%)粪便细菌培养阳性,其中志贺菌属感染14例(53.8%),大肠埃希菌属感染5例(19.2%),沙门菌属感染3例(11.5%),肺炎克雷伯杆菌、嗜水气单胞菌、摩氏摩根菌、雷氏普罗威登斯菌感染各1例(3.8%)。年龄≤60岁患者病原菌的检出率高于年龄﹥60岁者(P﹤0.05)。志贺菌属感染以黏液便、水样便为主,大肠埃希菌与沙门菌感染以稀便为主。志贺菌、大肠埃希菌及沙门菌普遍对氨苄西林耐药,对β-内酰胺酶类、头孢菌素类和喹诺酮类等抗菌药物产生不同程度的耐药性;尚未发现病原菌对碳青霉烯类抗菌药物产生耐药性。结论肠道门诊细菌感染性腹泻患者粪便细菌培养阳性率较低,仍以志贺菌属为主要病原菌。监测病原菌分布、药敏结果,合理选择抗菌药物对降低细菌耐药十分重要。     

Molecular detection and antimicrobial resistance of diarrheagenic Escherichia coli strains isolated from diarrheal cases

OBJECTIVE: To identify and classify Iranian isolates of diarrheagenic Escherichia coli (E. coli) on the basis of presence of virulence genes and to determine antibiotic susceptibility of isolated strains. METHODS: The current cross-sectional study was conducted in 2005 at the Pasteur Institute, Tehran, Iran. One hundred and ninety-three diarrheagenic E. coli isolated from diarrheal patients in different regions of Iran were included in current study. Virulence factor genes for diarrheagenic E. coli were detected by polymerase chain reaction. RESULTS: Of the 193 diarrheagenic E. coli detected by PCR, 86 (44.5%) were Shiga toxin-producing E. coli STEC, 74 (38.4%) enteropathogenic E. coli EPEC, 19 (9.8%) enteroaggregative E. coli, and 14 (7.3%) enterotoxigenic E. coli isolates. Susceptibility to 12 clinically important antimicrobial agents was determined for 193 strains of diarrheagenic E. coli. A high incidence of resistance to tetracycline (63%), ampicillin (62%), streptomycin (56%), amoxicillin/clavulanic acid (44.5%), trimethoprim/sulfamethoxazole (39.5%), and cephalothin (37%) was observed. CONCLUSION: The STEC and EPEC strains with high resistance to tetracycline and ampicillin, but highly susceptible to quinolones are among the most important causative agent of diarrhea in Iran. This study suggests that antimicrobial resistance is widespread among E. coli strains colonizing Iranian patients. Guidelines for appropriate use of antibiotics in developing countries require updating.     

Multiplex Polymerase Chain Reaction for Rapid Identification of Diarrheagenic Escherichia coli

Despite the fact that diarrhaegenic Escherichia coli (DEC) has been identified as a major etiologic agent of childhood diarrhea which represent a major public health problem in developing countries, only a few studies have been performed in Bangladesh to identify these organisms. To detect DEC in patients with acute diarrhea, a total of 300 stool specimens were tested by multiplex polymerase chain reaction (PCR). The multiplex PCR was designed for the detection of target genes of "eae" for enteropathogenic E. coli (EPEC), "stx" for enterohemorrhagic E. coli (EHEC), "ipaH" for enteroinvasive E. coli (EIEC), "aspU", "CVD432" and "aggR" for enteroaggregative E. coli (EAEC) as well as "elt" and "est" for enterotoxigenic E. coli (ETEC). Out of 300 stool specimens collected from patients with acute diarrhea, the DEC was detected in 18% (54/300) cases. The dominating strain was ETEC (13%, 39/300), followed by EAEC (5%, 15/300) and no EHEC, EIEC and EPEC could be detected. Both heat-stable toxin (ST) and heat-labile toxin (LT) genes of ETEC were detected in 66.68% (26/39) strains and only ST or LT as single gene was detected in 23.07% (9/39) or 10.25% (4/39) strains respectively. The multiplex PCR assay could be used as a rapid as well as efficient diagnostic tool for identification of DEC in the clinical laboratory settings.     

小儿细菌性腹泻病原菌分析及耐药变迁

目的 :了解引起小儿细菌性腹泻的主要病原菌及其耐药的变迁。方法 :肠道病原菌常规分离鉴定方法。结果 :从 2 0 15 7例北京儿童医院急性腹泻患者粪便中分离出沙门菌属、志贺菌属、变形菌属及致病性大肠杆菌共 13 44株 ,总检出率为 6.7%。其中志贺氏菌属 10 3 0株 ,检出率为 76.7%。福氏志贺菌占志贺菌属 82 .0 % ,其次是宋内志贺氏菌占 17.7%。沙门菌属 178株 ,总检出率为 13 .2 %。变形杆菌属 12 4株 ,总检出率 9.2 % ,以奇异变形杆菌为主。致病大肠杆菌 12株 ,总检出率 0 .9%。福氏痢疾杆菌对 β-内酰氨酶类耐药率有所增加 ,阿莫西林 /棒酸的耐药率也有所增加 ;对喹诺酮类抗生素的耐药率有所下降 ;对头孢三代类几乎都是敏感的 ;对氯霉素高度耐药。宋内氏痢疾杆菌、沙门氏痢疾杆菌对喹诺酮类的耐药率有所下降。结论 :小儿细菌性腹泻以志贺氏菌为主 ,其中又以福氏痢疾杆菌占绝对优势。儿童感染的福氏痢疾杆菌对以前常用的氯霉素、氨苄青霉素、哌拉西林、阿莫西林 /棒酸的耐药率增高 ;对头孢三代都较敏感。环丙沙星治疗福氏痢疾杆菌仍然是敏感的。治疗宋内痢疾杆菌可选用氨苄西林     

Orphan airlift. Enteric pathogens isolated from Vietnamese children immigrating to the United States.

Isolation studies for bacterial and parasitic agents were carried out on stool specimens from Vietnamese infants at the time of their mass airlift to the United States. One or more bacterial pathogens were found in 49% of the 367 stool specimens cultured. The isolates included enteropathogenic Escherichia coli (161), Shigella (16), Salmonella (15), but no Salmonella typhi or Vibrio cholerae. Parasites identified in 88 stool specimens included Giardia lamblia (10), Ascaris lumbricoides (7), and Entamoeba histolytica (1). Transmission of agents to volunteers probably occurred, because 48% of 272 adults questioned had diarrhea shortly after caring for the children, and stool cultures from these adults resulted in the isolation of E coli (105), Salmonella (1), and Shigella (3).     

南京地区儿童肠道感染致病性大肠埃希菌血清型的分布及耐药性

目的:了解南京地区儿童细菌性腹泻中致病性大肠埃希菌(Escherichia coli,E.coli)的主要血清型和对抗生素的敏感性.方法:对5 409例粪便标本进行分离培养并用血清学方法鉴定E.coli血清型,采用纸片扩散法测定E.coli对常用抗生素的敏感性.结果:5 409例粪便标本中分离出633株E.coli,检...