SPA协同凝集试验检测肠产毒性大肠杆菌不耐热肠毒素的研究

本文报道应用葡萄球菌A蛋白(SPA)协同凝集试验检测55株产毒性大肠杆菌不耐热肠毒素,结果与Y-1细胞培养法基本一致。此外,以血平板上培养菌用多粘菌素及三硝基甲苯溶解制备不耐热肠毒素,用协同凝集试验进行检测,结果较其它测毒方法敏感、特异、简单、经济、是一种检测不耐热肠毒素(LT)可行的方法,特别适用于基层的实验室。     

广州市远郊九佛农村5岁以下儿童产毒性大肠杆菌(ETEC)腹泻的定点研究

1988年3月—5月在广州远郊九佛农村两个自然对342名不足5岁儿童的ETEC腹泻作定点研究。发生腹泻186人次,估算发病率为1.26次/人/年。检出病原体6种71株,检出率38％(71/186),依次为ETEC45株:轮状病毒和志贺氏菌各11株,气单胞菌2株,沙门氏菌和致病性大肠杆菌(EPEC)各1株。ETEC的三种肠毒素基因探针(热敏肠毒素LT,热稳定肠毒素ST-H和ST-P)的检测结果依次为16.2％(30/186)、3.7％(7/186)、1.7％(3/186),另外,同时具有二种肠毒素(LT+ST)的ETEC有5株占2.6％(5/186)。ETEC的抗药性普遍存在,多抗性尤为严重,最少的抗9种,最多的竟抗20种。LT阴性(LT-)菌的多抗性强度显著大于LT~+菌(P<0.05)。两种菌对痢特灵,呋喃妥因、床大霉素、卡那霉素都高度敏感,对青霉素、万古霉素、杆菌肽、新生菌素、麦迪霉索具有较强抗性。ETEC中存在7种耐药模式,其中3种为ETEC模式,4种志贺氏模式,这在国内未见报道,对深入研究志贺氏菌的耐药机理有实际意义。     

平板免疫溶血法检测产毒性大肠杆菌不耐热肠毒素

产毒性大肠杆菌(ETEC)是近年发现的一种既能感染儿童,也能感染成人,传播较为广泛的腹泻病原菌,有时症状酷似霍乱。与其它二种类型的病原性大肠杆菌(肠道致病性大肠杆菌和肠道侵袭性大肠杆菌)不同的是它尚能引起多种幼畜的腹泻。因此产毒性大肠杆菌的检测对于腹泻病原学诊断,流行病学以及人畜腹泻的防治有一定的意义。国内外已有多种方法可以测定大肠杆菌不耐热肠毒素(LT),     

SPA协同凝集试验快速检测大肠杆菌不耐热肠毒素

我们在做产肠毒素大肠杆菌(ETEC)质粒电泳分析过程中,建立了金黄色葡萄球菌A蛋白(SPA)协同凝集试验检测大肠杆菌不耐热肠毒素(LT),现将结果报告如下。材料和方法一、菌种:5株ETEC标准株来自中国药品生物制品检定所,24株人源ETEC菌株分别来自军事医学科学院、解放军302医院和本所。二、培养基:SPA协同凝集试验和兔肠结扎用Biken NO_2产毒培养基。质粒电泳用LB培养基。三、SPA协同凝集试验:将ETEC标准株,待检株和阴性对照株分别接种1ml Biken NO_2产毒培养基,37℃振荡培养6～7小时,15000rpm离     

产肠毒素大肠杆菌快速检测方法的建立和评价

目的 利用环介导等温扩增（LAMP）技术,建立产肠毒素大肠杆菌（ETEC）的快速、便捷、敏感、特异的检测方法,并对该方法的特异性和敏感性进行评价,为实验动物检测和细菌性腹泻的诊断提供技术支持。方法 根据GenBank公布的产肠毒素大肠杆菌的LT毒素基因序列（S60731.1）设计外引物和内引物进行LAMP扩增,对LAMP特异性和敏感性与PCR方法做比较。结果 建立的LAMP方法检测限为100pg,灵敏度是PCR的10倍以上并具有较高的特异性,利用该方法对27份猴腹泻样品进行LAMP和PCR方法检测, LAMP（60min内）检测结果与PCR符合率为100%,而LAMP（90分钟内）检测敏感性高于PCR。结论 建立了一种用于检测肠毒性大肠杆菌（ETEC）的LAMP检测方法,该方法特异性强,灵敏度高,方便快捷,适合于ETEC临床快速检测。     

单克隆抗体酶联免疫试验诊断产肠毒素大肠杆菌胃肠炎及其在流行病学中应用的研究

产肠毒素大肠杆菌(ETEC)是引起婴幼儿腹泻的主要病原体,所产毒素主要是不耐热肠毒素(LT)和耐热肠毒素(ST)。目前国内对ETEC腹泻的流行特征报道很少,对检测ETEC的方法评价不一。本研究用单克隆抗体酶联免疫吸附试验(McAb-ELISA)和单克隆抗体免疫溶血试     

大肠杆菌热稳定肠毒素的检测分析

目的:探讨大肠杆菌热稳定肠毒素的检测方法与效果。方法:采用三种方法检测大肠杆菌的热稳定肠毒素。结果:酶联免疫吸附实验与双向琼脂扩散实验的LT检出率与实验灵敏度比乳鼠罐胃实验要高,而且酶联免疫吸附实验能同时测定十几个样品。结论:三种方法检测大肠杆菌热稳定性肠毒素,其中酶联免疫吸附实验方法特异性强、重复性好;双向琼脂扩散实验是测定LT的经典方法,敏感性较高;乳鼠实验被认为是测定ST的常规方法,但其检出不高且受很多因素制约。     

上海地区婴幼儿产肠毒素大肠菌腹泻的初步报告

本文报道了1983年上海地区7～9月份自1～3岁腹泻幼儿中分离的产肠毒素大肠菌(ETEC)情况。在109例1～3岁腹泻幼儿中应用改良Elek试验测定不耐热肠毒素(LT),乳鼠法测定耐热肠毒素(ST),检出ETEC 17株,检出率为15.59％,其中ST阳性株占47.08％,LT阳性株占11.76％,LT和ST同时阳性的菌株占41.18％。同期自同年龄组79名正常幼儿中分离到ETEC5株,分离率为6.33％。     

平板免疫溶血试验测定大肠杆菌不耐热肠毒素(LT)

产毒性大肠杆菌(ETEC)是人和家畜感染性腹泻的重要病原,可产生二种不同类型的肠毒素,即不耐热肠毒素LT和耐热肠毒素ST。虽然已有多种测定LT的方法,但均有一定的局限性,作者根据被动免疫溶血试验的原理,对检测方法作了如下重要改进:(1)从固体培养基表面直接挑取菌苔,不经再培养提取LT,缩短了检测时间,简化了鉴定程序;(2)在琼脂糖中加入未用毒素致敏的羊红血球,因此一个血平板可同时鉴定若干不同菌株制备的毒素标本;(3)用生长在     

肠毒素基因结构表达与变异

霍乱肠毒素(CT)与大肠杆菌不耐热肠毒素(LT)在结构、功能与致病性等方面的相似性已有许多报导。随着研究的深入,逐渐发现CT与LT不完全相同,不同株的霍乱弧菌(VC)产生的CT量及CT抗原性可有不同;产肠毒素大肠杆菌(ETEC)产生的LT也是如此。此外还发现许多其他肠道菌也有不少菌株可产生不耐热肠毒素。细菌性腹泻的预防还有     

Comparison of methods in the detection of enterotoxigenic Escherichia coli in a Malaysian laboratory

The prevalence of Enterotoxigenic Escherichia coli (ETEC) in 433 stool samples from diarrhoeal cases of all ages was studied using two commercially available test kits for the detection of heat labile toxin (LT) and the infant mouse assay for the heat stable toxin (ST). 16 samples (3.7%) were positive for ETEC, of which nine were producing ST alone, six LT alone and only one was producing both LT and ST. Although the percentage of isolation rate was low, its occurrence was almost as common as the Shigella spp and Salmonella spp in the same study. Of the two test kits examined, the Phadebact ETEC-LT Test 50 (Pharmacia Diagnostics, Uppsala, Sweden) was found to be more suitable for use in a routine diagnostic laboratory. Ten out of 12 (83%) of the strains tested were resistant to one or more antibiotics.     

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.     

Enterotoxigenic Escherichia coli infection in childhood diarrhoea in Mombasa, Kenya

This study was carried out at the Coast General Hospital in Mombasa, Kenya, during the dry month of March, 1984. Stool specimens were collected from 81 infants and children aged 0-36 months and with diarrhea of less than 7 days' duration. 35 age-matched children, who visited the hospitals with complaints other than gastrointestinal, served as controls. None of the children had received previous antibiotic therapy. Stools were checked for enterotoxigenic Escherichia coli (ETEC). E. coli isolates were assayed for labile toxin (LT) and stable toxin (ST) production by the Biken test and the suckling mouse assay, respectively. 19 ETEC were isolated from children with diarrhea, constituting an isolation rate of 23.5%. No ETEC were isolated from the controls. ST producers predominated (94.7%). Results indicate that the rates of ETEC isolation increase with age. In the majority of cases (16/19) ETEC caused diarrhea which was watery, with the number of motions ranging from 3 to 10 times. Fever was present in 9 patients. Mucus and blood were observed in very few cases. Vomiting was frequent (10/19) but abdominal pain was less common (5/10).     

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.

     

妊娠高血压综合征患者红细胞钠钾测定

应用经典冲洗法和电脑控制的原子吸收光谱分析法检测,正常孕妇RBC内外Na~+、K~+浓度,妊娠高血压综合征(妊高征)患者RBC的K~+以及血浆Na~+、K~+均无明显变化;妊高征患者RBC内Na~+含量增多和Na~+/K~+值较正常孕妇升高,尤以重度妊高征为明显,提示RBC内Na~+增多在妊高征的发生与发展方面可能起重要作用。     

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。     

妊娠高血压综合征病人血清白细胞介素-6 水平的测定

①目的探讨妊娠高血压综合征(妊高征)病人血清IL-6水平的变化及其与妊高征发病的关系.②方法采用双抗体夹心酶联免疫吸附法(ELISA),测定了60例妊高征病人(其中轻度、中度、重度各20例)及35例正常晚期妊娠妇女血清IL-6浓度.③结果妊高征组血清IL-6含量明显高于正常妊娠组,差异有显著性(t=2.165,P＜0.05).中、重度妊高征组IL-6含量与轻度及正常妊娠组比较,差异有显著性(F=8.412,q=4.365～6.053,P＜0.05、0.01),轻度妊高征组IL-6含量与正常妊娠组比较,差异无显著性(q=2.102,P＞0.05).④结论血清中IL-6的升高参与了血管内皮损伤过程,IL-6可能在妊高征的发病过程中起一定的作用.     

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。     

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。