首页 > 文献资料
-
cagA和cagM在中国人群感染幽门螺杆菌中的检测
cag致病岛(cag pathogenicity island)为新近在cagA表达阳性的幽门螺杆菌(Hp)菌株中发现的又一致病相关的基因群,其编码蛋白被认为是毒素及毒素转运机能相关的分泌系统.cag致病岛被认为是由水平转移的方式来源于质粒或噬菌体,具有部分或全部丢失等不稳定性表现.
-
牙周致病菌中毒力岛的研究进展
近年来,随着分子生物学研究的不断深入,在细菌学领域出现了一些新的概念,毒力岛即为其中之一.1986年Hacker等[1] 在泌尿道致病性大肠杆菌(LJPEC)536的染色体上发现两个可以发生缺失的大片段,片段丢失后,细菌产生溶血素和P菌毛的能力随之丧失,细菌的毒力受到影响.
-
胃疾病中幽门螺杆菌细胞毒相关基因A和E与白细胞介素-8相关性研究
幽门螺杆菌(Helicobacter pylori,Hp)是一种革兰染色阴性,呈弧形、S型或海鸥状的微需氧菌,专性定植于人胃黏膜上皮表面.Hp普遍被认为是慢性胃炎、胃溃疡、胃癌及胃黏膜相关淋巴组织淋巴瘤的致病因子,但其确切的致病机制尚未阐明.目前多数学者认为,Hp感染所致的胃组织损伤程度及临床症状的严重程度同Hp菌株的毒力相关.细胞毒相关基因A(cytotoxin association gene A,CagA)及Cag毒力岛(Cag pathogenicity island,CagPAI)是目前Hp致病机制研究的热点.经典的观点认为,CagA基因阳性菌株诱导胃黏膜上皮细胞分泌白细胞介素(IL)-8,介导强烈的炎症反应[1].然而近年来研究表明CagPAI中的其他基因在诱导IL-8分泌中也起重要作用.本实验旨在进一步探讨CagPAI基因在致不同胃疾病中的地位.
-
耶尔森菌强毒力岛的研究现状
毒力岛(pathogenicity island,PAIs),是携有毒力基因,而且极有可能是通过噬菌体介导的水平转移而来的染色体上的 DNA大片段.象这样的毒力岛已经在许多菌群中发现,这些菌包括:大肠杆菌、沙门菌、幽门螺旋杆菌和霍乱弧菌[1]以及克雷伯菌和枸橼酸菌[2].毒力岛在肠道菌群中的广泛分布及其特殊的结构与功能,对于研究新型病原微生物出现的机理和进一步了解微生物世界具有重要的意义.本文就目前耶尔森菌强毒力岛(high pathogenicity island,HPI)的研究现状及意义作一综述.
-
幽门螺杆菌CagA蛋白研究进展
幽门螺杆菌(Helicobacter pylori,Hp)分泌的许多毒力因子与胃部疾病有关,其中毒素相关基因A(cytotoxin-associated gene A,cagA)表达的蛋白CagA得到特别关注.cag致病岛(cag pathogenicity island,cagPAI)编码的Ⅳ型分泌系统(T4SS)将CagA运输到胃上皮细胞,一旦进入胃上皮细胞,CagA通过依赖或不依赖酪氨酸磷酸化与多种细胞蛋白作用,调控细胞生长和运动相关的信号通路,使胃上皮细胞发生转化而致癌变.
-
携带毒力岛(HPI)大肠杆菌性小儿腹泻
[ Objective] To investigate the etiologicla status of etiologica status of high - pathogenicity island - arboring Escherichia coli (HPIEC) in diarrhea disease among children. [Method] Diarrheagenic Escherichia coli was isolated and identified from the stool specimens of 1032 children with diarrhea diseases by culturing, serotyping, Polymerase chain reaction amplification (PCR), the High- pathogenicity island- harboring Escherichia coli (HPIEC) was identified by PCR and in situ hybridization. [ Results] A total of 652 strains of E. Coli isolated from 1032 stool speci mens and confirmed by serotyping,PCR and colony hybridization out of which 225 were identified as diarrheagenic E. Coli, including 20 EPEC, 81 ETEC,47 SLTEC ,74 ESIEC, and 3 EIEC strains. 112 (17.2 % ) irp2 virulent gene positive E. Coli (HPIEC) were detected from the 652 strains, out of which 24 were from the 74 ESIEC strains and 17 from the 47 SLTEC strains. The typical clinical symptoms of children with diarrhea disease caused by HPI - harboring E.coli included anorexia( 87.5 % ), abdominal pain (58.0 % ), diarrhea ( 75.9 %, Over six episoders, mostly of mucous stool a day), and fever(50.9 % ). [Conclusion]High - pathogenicity island - harboring E. Coli is one of the important pathogens of diarrhea diseas es in children.