上海地区幽门螺杆菌cagA基因3‘区和vacA基因的多态性分析及其临床意义

目的：探讨上海地区人群杆菌（Ｈ．ｐｙｌｏｒｉ）ｃａｇＡ基因３’区和ｖａｃＡ基因的多态性及其临床意义。方法：９９株Ｈ．ｐｙｌｏｒｉ菌株分离自１７例慢性浅表性胃炎（ＣＳＧ）、２１例慢性萎缩性胃炎（ＣＡＧ）、１９例胃溃疡（ＧＵ）、２３例十二指肠溃疡（ＤＵ）和１９例胃癌（ＧＣ）患者。用聚合酶链反应（ＰＣＲ）技术对Ｈ．ｐｙｌｏｒｉ菌株的ｃａｇＡ基因３’区和ｖａｃＡ基因基因信号序列及中间区等位基因进行扩增和检     

幽门螺杜菌cagA,vacA基因的调查及其临床意义

目的 调查广州地区患者感染幽门螺杆菌（Ｈｐ）的细胞毒素相关基因（ｃａｇＡ）及空泡毒素基因（ｖａｃＡ）亚型的流行情况,探讨Ｈｐ ｃａｇＡ及ｖａｃＡ亚型与Ｈｐ相关性胃肠疾病间的关系。方法 自广州地区不同疾病患乾胃黏膜中分离得到１９１株Ｈｐ,抽提各株菌的总ＤＮＡ,采用特定引物对各株菌ｃａｇＡ３’端、ｖａｃＡ中间序列（ｍ）及信号序列（ｓ）进行ＰＣＲ检测。结果 广州地区Ｈｐ ｃａｇＡ阳性者占８５．３％（１６     

上海人幽门螺杆菌vac A基因表型与相关胃肠疾病

目的 探讨用ｖａｃＡ基因表型检测对幽门螺力（Ｈｐ）进行分型,并分析不同基因型与相关胃肠疾病之间的关系,方法 对临床胃黏膜标本中Ｈｐ菌株进行分离培养及其总ＲＮＡ抽提,逆转录聚合酶链反应检测ｖａｃＡ基因表型,结果 ５０株临床分离Ｈｐ菌株ｖａｃＡ基因表型ｓｌ／ｍ２型４６株（２％）ｓｌ／ｍｌ型４株（８％）,未发现ｓ２型,结论 上海人Ｈｐ菌株ｖａｃＡ基因绝大多数表达ｓ１／ｍ２型,ｓｌ／ｍ２基因表型分布于所有     

cagⅡ在胃十二指肠疾病患者幽门螺杆菌中的检出率及其与幽门螺杆菌相 …

目的：探讨ｃａｇⅡ在胃十二指肠疾病患者幽门螺杆菌（Ｈ．ｐｙｌｏｒｉ）中的检出率及其与Ｈ．ｐｙｌｏｒｉ相关性疾病的关系。方法：Ｈ．ｐｙｌｏｒｉ菌株分离自１０７例胃十二指肠疾病患者，其中慢性胃炎６７例，消化性溃疡３４例，胃癌６例。采用聚合酶链反应（ＰＣＲ）技术，对１０７株Ｈ．ｐｙｌｏｒｉ菌株ｃａｇⅡ中的５９７ｂｐ片段进行扩增。结果：１０７株Ｈ．ｐｙｌｏｒｉ菌株的ｃａｇⅡ了性检出率为６９．２％（７４／１     

具有cagA、vacA基因的幽门螺杆菌感染与胃、十二指肠疾病的关系

为初步探讨南京地区具有ｃａｇＡ、ｖａｃＡ基因幽门螺杆菌（Ｈｐ）的感染状况以及ｃａｇＡ、ｖａｃＡ基因的存在与表达和胃、十二指肠疾病的关系，利用ＰＣＲ技术扩增ｃａｇＡ、ｖａ－ｃＡ基因，对１０４份临床分离Ｈｐ菌进行检测分析。结果：（１）消化性溃疡患者ｃａｇＡ＋、ｖａｃＡ＋Ｈｐ感染率高于慢性胃炎患者（χ２＝１０．６，Ｐ＜０．０１）；（２）ｃａｇＡ＋组胃炎炎症的急性活动程度重于ｃａｇＡ－组（χ２＝９．９９，Ｐ＜０．０１），而ｃａｇＡ十组肠上皮化生率与ｃａｇＡ－组间无显著差异（χ２＝１．６４，Ｐ＞０．０５）；（３）胃癌患者以ｃａｇＡ＋、ｖａｃＡ＋菌株及ｃａｇＡ－、ｖａｃＡ＋菌株感染多见，胃癌感染后者的６例均为腺癌。结果提示消化性溃疡患者以具有ｃａｇＡ、ｖａｃＡ基因的Ｈｐ感染多见；ｃａｇＡ基因的存在与表达可能与炎症的急性活动程度有关，而与肠化生无关；ｃａｇＡ、ｖａｃＡ基因的存在与表达可能均与肿瘤的形成有关，ｖａｃＡ基因是否与腺癌形成有关，有待研究。     

中国幽门螺杆菌vacA基因的等位变异

目的 明确中国幽门螺杆菌（Ｈｅｌｉｃｏｂａｃｔｅｒ ｐｙｌｏｒｉ,Ｈｐ）全长ｖａｃＡ基因的等位变异及其与西方主要菌株基因序列的差异。方法 从５例胃病患者胃黏膜粘栓组织中分离培养２２个单个Ｈｐ克隆,以Ｗｅｓｔｅｒｍ ｂｌｏｔ确定ｖａｃＡ表型特点,以体外细胞毒性试验研究其活性。然后选择５株有代表性的克隆进行基因组ＤＮＡ抽提、ＰＣＲ扩增及ｖａｃＡ基因全序列测定、分析。结果 ５株中４株ｖａｃＡ表达阳性。只     

幽门螺杆菌感染对胃黏膜上皮细胞增殖的影响

空泡毒素 (ＶａｃＡ)是幽门螺杆菌 (Ｈｐ)的重要致病因素。根据其编码基因ｖａｃＡ信号序列的不同可分为ｓ1ａ ,ｓ1ｂ ,ｓ1ｃ和ｓ2型。ｖａｃＡｓ1ａ型菌株与胃十二指肠疾病的关系更为密切 ,可能是致胃十二指肠疾病的高毒力菌株。不同ｖａｃＡ类型的菌株对于上皮细胞增殖的影响存在差异[1] 。因此 ,我们主要观察感染ｖａｃＡｓ1ａ阳性Ｈｐ菌株 ,ｖａｃＡｓ1ａ阴性Ｈｐ菌株及Ｈｐ阴性的慢性胃炎和十二指肠球部溃疡 (ＤＵ)患者胃黏膜上皮细胞增殖情况 ,以探讨Ｈｐ及其不同菌株感染对细胞增殖的影响以及其可能的作用机制。材料与方法一、标本中…     

cag致病岛与幽门螺杆菌致病作用的关系

幽门螺杆菌（Ｈ．Ｐｙｌｏｒｉ）诱导疾病发生的分子机制目前尚不清楚，针对Ｈ． ｐｙｌｏｒｉ致病相关因素的研究仍在继续深人。１９９６年Ｃｅｎｓｉｎｉ等［１］在ｃａｇＡ阳性Ｈ ｐｙｌｏｒｉ菌株中发现的新的ＤＮＡ片段──ｃａａ致病岛，被认为是Ｈ． ｐｙｌｏｒｉ中的又一致病相关因素。本文就ｃａｇ致病岛与Ｈ．ｐｙｌｏｒｉ相关致病因子的关系作一简要综述。 一、致病岛的概念 致病菌中编码毒素、粘附因子、侵袭因子或其他毒力因子的致病基因存在于细菌染色体特定区域中，并出现于诸如转座子、质粒、噬菌体等可转染的遗传学元件中…     

不同病变胃组织端粒酶活性及其与让螺杆菌感染的关系

分析不同病变胃粘膜端粒酶活性的差异及其与幽门螺杆菌（Ｈ．ｐｙｌｏｒｉ）感染的关系，探讨端粒酶活性、Ｈ．ｐｙｌｏｒｉ感染与胃粘膜癌变的关系。方法：应用端粒重复扩增法测定正常胃粘膜、癌前病变和胃癌组织中的端粒酶活性，用酶免疫法检测Ｈ．ｐｙｌｏｒｉ感染患者的血清Ｈ．ｐｙｌｏｒｉ－ＣａｇＡ－ＩｇＧ水平，并分析端粒酶活性与Ｈ．ｐｙｌｏｒｉ－ｃａｇＡ－ＩｇＧ水平的关系。结果：１７２例胃镜活检标本中，下沉胃粘膜     

幽门螺杆菌感染患者胃癌及癌旁组织中p53,p16和bc1—2基因的表达

研究幽门螺杆菌（Ｈ．ｐｙｌｏｒｉ）感染胃癌得胃粘膜病变中抑癌基因ｐ５３、ｐ１６和关键性凋亡调节基因ｂｃ１－２蛋白的表达,进一步探讨Ｈ．ｐｙｌｏｒｉ在胃癌发生、发展过程中作用的分子机制。方法：胃镜检查及外科手术中取４０例胃癌患者的癌组织和癌旁２ ｃｍ处组织各２块,石蜡包埋,切片ＨＥ染色作病理诊断及免疫组化检查ｐ５３、ｐ１６及ｂｃ１－２蛋白的表达。Ｈ．ｐｙｌｏｒｉ阳性由快速尿素酶试验结合病理染色／＾１     

广东地区幽门螺杆菌空泡毒素基因亚型及其与胃肠疾病的关系

目的：1)调查广东地区患感染幽门螺杆菌(Hp)的空泡毒素基因(vacA)亚型的流行情况；2)探讨不同的vacA亚型与协相关胃肠疾病问的关系。方法：自广东地区不同疾病患胃黏膜中分离得到191株Hp，抽提各株菌的总DNA，采用特定引物对各株菌vacA基因中间序列(m)及信号序列(s)进行PCR检测。结果：1)广东地区患感染Hp vacA基因亚型有sla／m2、sla／mlb、slb／m2、slb／mlb、s2／m2及sla／mlb—m2六种组合、各亚型所占比例分别为88．0%(168／191)、7．3％(14／191)、3．1％(6／191)、0．5％(1／191)、0．5％(1／191)及0．5％(1／191)；2)vacA亚型在不同Hp相关胃肠疾病中的检出率无显性差异。结论：1)广东地区Hp vacA基因亚型以sla／m2占绝大部份；2)不能单纯以vacA亚型作为预测感染Hp后的疾病转归。     

新疆维吾尔族人群幽门螺杆菌vacA基因型分布特征

目的探讨新疆维吾尔族胃病患者感染幽门螺杆菌（Helieobacter pyroli,Hp）vacA基因亚型的分布状况及与胃病的关系。方法临床收集维吾尔族人群慢性浅表性胃炎、慢性萎缩性胃炎、胃溃疡和胃癌患者胃镜活检标本,采用Hp分离培养技术对其进行培养鉴定;采用Chelex 100提取Hp基因组,聚合酶链反应-序列特异性引物（PCR-SSP）对Hp基因组DNA进行vacA基因亚型检测,并对vacA基因亚型与特定疾病间的关系进行分析。结果胃活检标本Hp培养阳性46例,上述4种病人vacAs区s1a型阳性率分别为78.6%（11/14）、63.2%（12/19）、66.7%（4/6）和85.7%（6/7）,vacAs区s2型阳性率分别为0（0/14）、5.3%（1/19）、0（0/6）和14.3%（1/7）,vacA m区m1b型阳性率分别为14.3%（2/14）、10.5%（2/19）、16.7%（1/6）和0（0/7）,vacA m区m2型阳性率分别为78.6%（11/14）、57.9%（11/19）、50.0%（3/6）和85.7%（6/7）。4种疾病间的vacA亚型分布差异均无统计学意义（P〉0.05）。结论新疆维吾尔族人群中Hp vacA亚型以s1a/m2型为主。     

上海地区幽门螺杆菌cagA基因3’区和vacA基因的多态性分析及其临床意义

探讨上海地区人群中幽门螺杆菌（H．pylori）cagA基因3’区和vacA基因的多态性及其临床意义。方法：99株H．pylori菌株分离自17例慢性浅表性胃炎（CSG）、21例慢性萎缩性胃炎（CAG）、19例胃溃疡（GU）、23例十二指肠溃疡（DU）和19例胃癌（GC）患者。用聚合酶链反应（PCR）技术对H．pylori菌株的cagA基因3’区和vacA基因信号序列及中间区等位基因进行扩增和检测。结果：99株H．pylori菌株中84株（84．8％）cagA基因阳性,其3’区产物大小均约650bp,属A型。vacA基因信号序列仅检出sla型,见于从94．1％（16／17）的CSG、952％（20／21）的CAG、89．5％（17／19）的GU、87．00（20／23）的DU和89．5％（17／19）的GC患者中分离的菌株（P＝0．87）;中间区等位基因仅检出m2型,见于从70．6％（12／17）的CSG、71．4％（15／21）的CAG、63．20（12／19）的GU、73．9％（17／23）的DU和57．9％（11／19）的GC患者中分局的菌株（P＝0．72）。结论：上海地区人群中H．pylori菌株的cagA基因3’区相对保守;绝大多数vacA基因属sla／m2型。本研究结果不支持这些基因的多态性与H．pylori感染临床结局相关的观点。     

Helicobacter pylori vacA genotypes and cagA status and their relationship to associated diseases

Helicobacter pylori (H. pylori ) is a major causativebacterium of chronic gastritis, peptic ulcer and mucosaassociated lymphoid tissue lymphoma in humans, and associated with an increased risk of gastric cancer[1 -8]. An important virulant factor of H. pylori is the vacuolating cytotoxin ( VacA ) encoded by vacA that induces cytoplasmic vacuolation in target cells both in vitro and in vivo[9-11]. VacA is produced as a 140 kDa precursor which contains an N-terminal signal peptide and an approximately 33 kDa C-terminal outer membrance exporter. The precursor is cleaved at both N-terminal and C-terminal and secreted into the extracellular milieu as a 95 kDa mature protein. The mature protein futher undergoes specific cleavage to yield 37 kDa and 58 kDa subunits[12-14] Although vacA is present in all H. pylori strains, only about 50% to 60% of strains can induce vacuolation of epithelial cells as assessed by the HeLa cell assay. vacA shows considerable genetic variation in H. pylori isolated from all over the world and contains at least two variable regions. The s region exists as sl or s2 allelic types. Among type sl strains, subtypes sla and slb have been identified. The m region occurs as ml or m2 allelic types. Specific vacA genotype of H. pylori strains are associated with the production of the cytotoxin in vitro, epithelial damage in vivo, and clinical consequences[15-27]. The other virulant factor is the cytotoxin-associated protein (CagA) encoded by the cytotoxin-associated gene (cagA). The cagA gene is present in about 60% to 70% of strains and all of these strains express the cagA. The presence of cagA is also associated with the production of the cytotoxin in vitro, and clinical outcome[24-30]. The aim of this study was (i) to identify vacA genotypes and cagA status of H. pylori isolated from Chinese patients; (ii) to evaluation the relatioship beween vacA genotypes, cagA status and related gastroenterological disorders.     

Helicobacter pylori vacA s1a and s1b alleles from clinical isolates from different regions of Chile show a distinct geographic distribution

AIM: To establish the most common vacA alleles in Helicobacter pylori (H pylori) strains isolated from Chilean patients and its relationship with gastritis and gastroduodenal ulcers. METHODS: Two hundred and forty five H pylori clinical isolates were obtained from 79 biopsies from Chilean infected patients suffering from gastrointestinal diseases. An average of 2-3 strains per patient was isolated and the vacA genotype was analyzed by PCR and 3% agarose electrophoresis. Some genotypes were checked by DNA sequencing. RESULTS: The most prevalent vacA genotype in Chilean patients was s1b m1 (76%), followed by s1a m1 (21%). In contrast, the s2 m2 genotype was scarcely represented (3%). The s1b m1 genotype was found most frequently linked to gastropathies (P<0.05) rather than ulcers. Ulcers were found more commonly in male and older patients. Curiously, patients living in cities located North and far South of Santiago, the capital and largest Chilean city, carried almost exclusively strains with the s1b m1 genotype. In contrast, patients from Santiago and cities located South of Santiago carried strains with either one or both s1a m1 and s1b m1 genotypes. Regarding the s2 m2 genotype, comparison with GenBank sequences revealed that Chilean s2 sequence was identical to those of Australian, American, and Colombian strains but quite different from those of Alaska and India. CONCLUSION: Differences in geographic distribution of the s and m vacA alleles in Chile and a relationship of s1b m1 genotype with gastritis were found. Sequence data in part support a hispanic origin for the vacA genotype. Asymmetric distribution of genotypes s1b ml and s2 m2 recedes H Pylori strain distribution in Spain and Portugal.     

cagA and vacA genotype of Helicobacter pylori associated with gastric diseases in Xi＇an area

AIM: To establish stock of clinical Helicobacter pylori (H.pylon) isolates, to perform cagA and vacA typing of these isolates, to evaluate the relationship between genotypes of cagA and vacA and upper gastrointestinal diseases and to assess the association of vacA genotypes with presence of the pathogenicity marker-cagA.METHODS: Clinical H.pylori strains were isolated from the antrum of 259 patients in Clumbia agar. The isolated H.pylori strains were identified by histology, and16SrRNA PCR.CagA genotypes were detected by colony hybridization, the probe was derived from the cloned plasmid PcagA, and digested by EcoRI-HindⅢ and the isolated PcagA DNA fragment was radioactively labelled by the random priming method. vacA genes types (s,m)and subtypes (s1a, s1b,s2) were typed by PCR. Vacuolating toxin was detected with neutral red absorb test. The results were treated statistically by χ2test, ttest, and rank sum test.RESULTS: A total of 192 clinical H. pylori strains were isolated and the stock of Helicobacter pylori was established. The total positive rate of cagA was 87 % in all gastric diseases,and 95 % in gastric cancer group. There was a difference between gastric cancer group and the other groups (P＜0.05)except duodenal ulcer group. The expression of type s1 of vacA was more than type s2 (P＜0.05), and, the expression of type m1 was equal to type m2. In gastric cancer group,there was a difference between s1a and s1b (P＜0.05), and s1a was more than s1b. Vacuolating toxins were more in Xi′an area isolates.CONCLUSION: The cagA+ vacA type s1 clinical isolates are more in Xi′an area, but this can not serve as an index to predict gastric cancer.     

广东地区幽门螺杆菌cagA基因与细菌定植及其致病性关系的研究

目的：分析广东地区细胞毒素相关基因（cagA）在幽门螺杆菌（H.pylori)中的分布情况及其与患者性别、年龄的关系；探讨H.pylori cagA在不同胃肠疾病发生中的作用及其与胃粘膜慢性炎症程度及H.pylori定植密度的关系。方法：采用改良Skirrow培养基分离培养得到191株H.pylori，用特定引物对各株细菌的cagA 3′端行聚合酶链反应（PCR）扩增鉴定；对其中83例患者再各取胃窦粘膜2块，经HE及Giemsa染色后观察胃粘膜慢性炎症程度及H.pylori定植密度。结果：广东地区H.pylori cagA阳性者占85.3%(163/191)；H.pylori cagA阳性率与患者的性别、年龄无关；消化性溃疡及胃癌患者的H.pylori cagA阳性率显著高于慢性胃炎患者；cagA阳性H.pylori菌株在胃粘膜表面的定植密度较cagA阴性菌株更高，引起的胃粘膜慢性炎症也更为严重；H.pylori的定植密度与其引起的慢性炎症程度呈正相关。结论：广东地区cagA阳性H.pylori感染者占绝大多数；cagA阳性菌株较cagA阴性菌株具有更强的致病力，可能引起更为严重的胃肠道损害。     

幽门螺杆菌vacA基因型及其表达产物与胃十二指肠疾病关系的研究

目的 探讨幽门螺杆菌ｖａｃＡ基因型及其表达产物－ＶａｃＡ与胃十二指肠疾病之间的关系。方法 用聚合酶链反应技术测定６２株从慢性胃炎,消化性溃疡和胃癌患者中分离获得的幽门螺杆菌（Ｈｐ）菌株的ｖａｃＡ基因型,用Ｈｅｌａ细胞测定Ｈｐ菌株体外ＶａｃＡ活性。     

贵阳地区幽门螺杆菌临床分离株中ureA、cagA、vacA、iceA基因的分布及分析

目的了解贵阳地区临床分离的幽门螺杆菌（Hp）的毒力基因ureA、cagA、vacA、iceA的分布特征,探讨不同毒力基因型与上消化道疾病的关系。方法用特异的16SrDNA聚合酶链反应进行临床分离Hp的菌种鉴定,对经过鉴定的152株幽门螺杆菌进行ureA、cagA、vacA、iceA基因及亚型的PCR检测。结果 ureA基因的检出率为100%（152/152）,vacA基因的检出率为100%（152/152）,vacA基因亚型以s1a-m2型为主,占76.3%（116/152）,cagA基因检出率为39.5%（60/152）,ieeA1基因检出率36.8%（56/152）,iceA2基因检出率为34.2%（52/152）,13.2%（20/152）的菌株iceA1和iceA2基因均阳性,不同基因型菌株在慢性胃炎和消化性溃疡中的检出率无统计学意义（P〉0.05）。结论贵阳地区幽门螺杆菌毒力基因vacA以s1a-m2型为主,cagA阴性比例高于cagA阳性,不同基因型菌株与消化性疾病间无明显相关性。     

Significance of cagA status and vacA subtypes of Helicobacter pylori in determining gastric histopathology: virulence markers of H. pylori and histopathology

BACKGROUND: It has been suggested that Helicobacter pylori strains containing the cytotoxin-associated gene A (cagA), and s1m1 genotype of vacuolating cytotoxin gene A (vacA) may have been associated with peptic ulcer disease. The aim of the present study was to analyze such an association of cagA presence and vacA subtypes of H. pylori with histopathological findings in patients with gastritis. METHODS: Sixty-five independent H. pylori strains isolated from Turkish patients with gastritis were analyzed. The antral biopsy specimens were processed for culture and histopathology. Histopathological features were recorded and graded according to updated Sydney system. The vacA subtypes and cagA gene were tested by polymerase chain reaction. RESULTS: Mild degree of antral density was associated with mild degree of gastric neutrophil infiltration (P = 0.010). Positive cagA status correlated significantly with the presence of atrophy (P = 0.035) and neutrophil infiltration (P < 0.001), but not with H. pylori density (P = 0.754) nor the degree of mononuclear cell infiltration (P = 0.945). The vacA subtypes were independent of gastric histopathology. The odds ratios for atrophy and neutrophil infiltration of cagA+ versus cagA- strains were 3.62 (95% confidence interval [CI]: 1.04-12.66) and 53.18 (95%CI: 11.08-255.23), respectively. CONCLUSION: The presence of the cagA gene is strongly associated with atrophic and active gastritis. Distinct vacA subtypes of H. pylori appear to have no association with histopathological findings of gastritis.