浙江人群幽门螺杆菌cagA/vacA优势基因型和不同基因型混合感染的调查

目的　了解消化性溃疡和慢性胃炎患者感染的幽门螺杆菌 (Hp)cagA vacA优势基因型及不同基因型Hp感染、混合感染与疾病的关系。 方法　选择胃窦、胃体双份活检标本均培养出Hp的 42例慢性胃炎 (CG)和 3 6例消化性溃疡 (PU )患者作为研究对象 ,采用聚合酶链反应 (PCR)检测156份Hp分离株的cagA基因、vacA基因的信号区 (s)和中间区 (m )亚型 ,分析Hp基因型及多株Hp混合感染在CG和PU中的分布。结果　胃窦标本cagA基因的检测中 78例患者中有 75例 (96.2 % )为cagA阳性 ,相应的胃体标本中 ,76例患者 (97.4% )为cagA阳性 ,有 1例 (1.3 % )患者胃窦、胃体检出cagA状态不一的Hp混合菌株。在胃窦标本的vacA基因分型中 ,s1a m1、s1a m2、s1a m1b、s1a m1b m2 4种vacA基因型在 78例患者中所占比例分别为 6.4% (5 78)、55.1% (43 78)、2 6.9% (2 1 78)和 1.3 % (1 78) ,多株混合感染为 3 .8% (3 78) ;而相应的胃体标本中 ,前述四种vacA基因型所占比例依次为 6.4% (5 78)、53 .8% (42 78)、2 5.6% (2 0 78)和 3 .8% (3 78) ,多株混合感染为 5.1% (4 78)。cagA+ s1a m2和cagA+ s1a m1b在胃窦标本中占 51.3 % (40 78)和 2 6.9% (2 1 78) ,而在相应的胃体标本中占 52 .6% (41 78)和 2 5.6% (2 0 78)。少量胃窦、胃体     

Whole CanA Gene Amplification of Helicobacter pylori and Its Fingerprinting by Restriction Fragment Length Polymorphism

To set up a method of amplification for the whole CagA gene of Helicobacter pylori and its fingerprinting by restriction fragment length polymorphism(RFLP),nested PCR was employed in combination with TD-PCR to amplify the gene and EcoRI and Hind Ⅲ were used to generate the RFLP fingerprinting.Target DNA fragments from 13 of 20 samples were successfully amplified and the relevant RFLP fingerprintings were obtained.It is concluded that the method can be used to amplify the whole CagA gene and CagA gene has apparent diversity of RFLP profile.     

幽门螺杆菌cagA、oipA、iceA1基因的检测及其意义

〔目的〕检测分离自胃炎、胃溃疡患者的幽门螺杆菌 (Hp)cagA、oipA、iceA1基因 ,了解这些基因与消化性疾病的关系。〔方法〕取 163份临床胃活检标本 ,用布氏平板分离培养Hp ,分离培养出来的细菌 ,用聚合酶链反应 (PCR)方法扩增cagA、oipA、iceA1基因片段 ,用卡方检验进行统计学分析。〔结果〕163份标本中检出Hp 5 8株 ,检出率为 3 5 .6%。ca gA基因的阳性率为 75 .9%(4 4 5 8) ,其中胃炎 66.7%(2 8 42 ) ,胃溃疡 10 0 %(16 16) ;oipA基因的阳性率为 46.6%(2 7 5 8) ,其中胃炎 2 6.2 %(11 42 ) ,胃溃疡 10 0 %(16 16) ;iceA1基因的阳性率为 3 1.0 %(18 5 8) ,其中胃炎 2 1.4%(9 42 ) ,胃溃疡 3 3 .3 %(9 16)。卡方检验分析表明胃溃疡患者HpcagA、oipA、iceA1阳性率均显著高于胃炎患者。〔结论〕HpcagA、oipA、iceA1毒力基因在胃溃疡患者的检出显著高于胃炎患者。     

Prevalence of Helicobacter pylori cagA genotype among dyspeptic patients in Southern Thailand

ObjectiveTo investigate the prevalence of Helicobacter pylori (H. pylori) infection in dyspepsia patients and its relation to virulence factor cagA gene.MethodsIn total, 110 gastric biopsies from dyspeptic patients were comparatively studied using rapid urease test and multiplex PCR. Multiplex PCR detected three genes of 16S rRNA, cagA, and ureC.ResultsH. pylori was detected in 14 gastric biopsies (13%). Significantly higher number of female were infected. Furthermore, cagA gene was found in all H. pylori–positive specimens. In addition, the result indicated that the multiplex PCR with annealing temperature at 57 oC was able to effectively amplify specific products.ConclusionThe results confirmed that high preva¬lence of cagA gene in H. pylori among dyspeptic patients in Southern Thailand.     

cagA positive and negative Helicobacter pylori strains are simultaneously present in the stomach of most patients with non-ulcer dyspepsia: relevance to histological damage

^a Institute of Internal Medicine, University of Siena, Siena, Italy, ^b Institute of Pathology, University of Siena, ^c IRIS, Siena, ^d Institute of Surgical Clinics, University of Siena, ^e Institute of Internal Medicine, University of Bologna, Bologna, Italy

Correspondence to: Dr N Figura, Institute of Internal Medicine, University of Siena, Policlinico Le Scotte, viale Bracci, I-53100 Siena, Italy.

Accepted for publication 6 February 1998

Background/Aims—Infection with Helicobacter pylori strains harbouring the cagA gene (cagA+) is associated with an increased risk of developing peptic ulcer and gastric cancer. The aim of this study was to assess whether H pylori isolates with different cagA status were present in patients with non-ulcer dyspepsia, and whether a variable cagA status is relevant to histological gastric mucosal damage and glandular cell proliferation.
Methods—Well separated H pylori colonies (between 2 and 25) from primary plates, per gastric area, for each of 19 patients with non-ulcer dyspepsia were examined for cagA by hybridisation. Western blotting was used to examine both representative colonies for CagA expression and the patients' sera for antibody response to CagA. Glandular gastric cell proliferation was assessed immunohistochemically.
Results—Of the 747 colonies examined, 45.3% were cagA+. All colonies from four patients were cagA+, and all colonies from two patients were cagA−. In 13 patients (68%) both cagA+ and cagA− colonies were found. CagA expression of isolates corresponded to their cagA status. H pylori strains with different CagA molecular masses were present in three patients. Results based on all 19 patients studied showed that the prevalence of cagA+ colonies in areas with mucosal atrophy associated or not with intestinal metaplasia (67.9%) was significantly higher than in normal mucosa (44.7%) and mucosa from patients with chronic gastritis (44.0%) (p< 0.001). High levels of cell proliferation were associated with histological atrophy with or without intestinal metaplasia, but not with the possession of cagA by organisms colonising the same mucosal sites.
Conclusions—Most patients with non-ulcer dyspepsia are infected by both cagA+ and cagA− H pylori colonies. The cagA status of infecting organisms may play a role in the development of atrophy and intestinal metaplasia.
(GUT 1998;:772-778)

Keywords: gastritis; Helicobacter pylori infection;  cagA;  mucosal atrophy;  cell proliferation

     

镇江地区H pylori的cagA基因及其3′可变区结构的变化

目的:评估镇江地区H pylori临床株的cagA基因阳性率、了解菌株CagA蛋白的可能分型、其羧端可变区EPIYA的数目以及与临床结果之间有无关联.方法:培养分离来自临床胃十二指肠疾病患者的H pvlori,提取基因组DNA,通过PCR方法检测H pylori cagA基因的状况.随机选择不同病种的cagA基因阳性(cagA~ )的PCR产物.通过转化质粒,进行cagA~ PCR产物测序,通过ExPASY-Tranlation软件获得cagA基因相应的CagA蛋白的氨基酸序列.国际标准株NCTC11637的cagA基因以及CagA蛋白序列通过搜索NCBI(www.ncbi.nlm.nih.gov)数据库获得.结果:60株H pylori临床株中,56例为cagA~ ,阳性率达93.3%.20例测序的结果表明,CagA蛋白结构可分为2种类型,19株东亚型和1株西方型.所有19株东亚型均为Yamaoka分型的A型,所有20例菌株的EPIYA的数目均为3个,与临床结果无关联.结论:cagA基因阳性率在不同病种之间无差异.镇江地区H pylori临床株的CagA蛋白的一级结构,与日本、韩国菌株一样,主要为东亚型,其CagA蛋白羧端可变区EPIYA数目均为3个,与临床结果无关联.     

幽门螺杆菌cagA基因片段原核表达载体的构建及其cagA基因和CagA蛋白及感染者血清抗体的检测

目的:构建幽门螺杆菌(Helicobacter pylori,Hp)cagA基因片段的原核表达系统,建立ELISA检测CagA及其抗体,了解表达CagA的Hp菌株(CagA Hp)感染与所致疾病种类的关系.方法:从快速尿素酶试验阳性的156例患者胃黏膜活检标本中分离Hp.采用PCR检测109株Hp cagA基因,并从临床菌株Y06中扩增2 148 bp的cagA基因片段(cagA1).构建cagA1原核表达系统,用SDS-PAGE检查目的重组蛋白(rCagA1)的表达情况,用Western blot和免疫双扩散试验鉴定rCagA1的免疫反应性和抗原性.建立ELISA,检测109株Hp CagA表达和相应患者血清中CagA抗体.分析CagA Hp感染与胃炎和消化性溃疡的关系.结果:80.8%胃黏膜活检标本中分离出Hp(126/156),97.2%的Hp菌株(106/109)cagA基因阳性.与文献报道比较,所克隆的cagA1片段核苷酸和氨基酸序列同源性分别为94.83%和93.30%.所构建的原核表达系统表达的rCagA1量约为细菌总蛋白的30.0%.rCagA1能与Hp全菌抗体发生结合反应,免疫家兔产生双扩散效价为1∶4的抗体.92.6%菌株(101/109)可表达CagA,88.1% 患者(96/109)血清CagA抗体阳性.消化性溃疡标本中CagA Hp菌株分离阳性率(97.9%)高于胃炎标本(88.5%),但无统计学差异(χ2=3.48,P>0.05).结论:本实验构建的原核表达系统表达的rCagA1有良好的免疫反应性和抗原性,建立的ELISA可用于Hp CagA及其抗体的检测,分离的Hp菌株cagA基因携带率和CagA表达率均很高.消化性溃疡和胃炎与其感染的Hp是否表达CagA无明显关系.     

新疆地区汉族和维吾尔族人群感染幽门螺杆菌cagA分布特征及与胃相关性疾病的关系

目的:探讨新疆地区汉族和维吾尔族慢性浅表性胃炎、慢性萎缩性胃炎、胃溃疡、胃癌患者感染幽门螺杆菌(H.pylori)细胞毒素相关基因(cagA)的分布特征及与胃相关性疾病的关系。方法:从92例胃相关性疾病的患者(汉族46例、维吾尔族46例)胃镜活检标本中分离培养H.pylori,抽提各菌株的总DNA,采用特异性引物进行PCR扩增检测H.pylori的cagA基因,并分析其分布特征及与胃相关性疾病的关系。结果:92株H.pylori菌株中cagA基因的检出率为84.8%,在所研究的4种疾病中汉族和维吾尔族患者感染的H.pylori cagA基因检出率差异无统计学意义(P>0.05);汉族和维吾尔族患者4种特定疾病的H.pylori cagA基因检出率差异无统计学意义(P>0.05)。结论:新疆地区汉族和维吾尔族间H.pylori cagA基因阳性率未见明显差异,特定胃相关性疾病间H.pylori cagA基因阳性率也未见明显差异。     

幽门螺杆菌vacA及cagA基因型与胃疾病的关系

目的探讨幽门螺杆菌(Hp)vacA、cagA基因型与胃疾病的关系。方法选取105例胃疾病病人,包括慢性浅表性胃炎(CSG)45例,慢性萎缩性胃炎(CAG)48例,胃癌(GC)12例。于胃窦处取3块胃黏膜,分别进行快速尿素酶反应、病理检查和聚合酶链反应(PCR)。提取胃黏膜基因组DNA,用6对引物检测Hp vacA、cagA基因的表达。结果快速尿素酶反应、病理检查均阳性的标本57例,Hp的阳性率为54.2%(57/105)。Hp vacA s1/m2、s1/m1、s2/m1、s2/m2的阳性率分别为53%(30/57)、18%(10/57)、8%(5/57)、21%(12/57);Hp cagA的阳性率为89%(51/57)。vacA、cagA基因型在CSG、CAG和GC之间差异无显著性(P>0.05)。结论Hp菌株的优势基因亚型为Hp cagA、vacA s1/m2;Hp vacA、cagA基因与特定胃疾病间无显著相关性,不能预示Hp感染的临床结果。