幽门螺杆菌毒力基因cagA、vacA和iceA与胃十二指肠疾病的关系

目的 了解长春地区就医人群中幽门螺杆菌（Helicobacter pylori,H. pylori）毒力基因分布,分析本地区H. pylori主要毒力基因型与胃十二指肠疾病关系。方法 将胃黏膜标本培养分离H. pylori并运用聚合酶链式反应（polymerase chain reaction,PCR）对H. pylori的三种毒力基因cagA、vacA（s1a、s1b、s1c、s2、m1a、m1b、m2、i1和i2）、iceA（iceA1和iceA2）及其亚型进行检测,分析H. pylori的毒力基因型与疾病之间的关系。结果 分离H. pylori 60株,标本依据病理诊断结果分为4组：消化性溃疡组（peptic ulcer disease,PUD）25株、非溃疡性消化不良组（non-ulcer dyspepsia,NUD）9株、糜烂性胃炎组（gastritis erode,GE）15株和胃癌组（gastric cancer,GC）11株。cagA基因的阳性率为90.0%,与阴性相比在疾病中的分布差异有统计学意义（χ2=8.4440,P=0.0270）。vacA基因的s1和s2亚型的阳性率分别为86.7%和13.3%。在s1阳性菌株中,s1c等位基因检出率最高为33.3%,其次s1a检出率为23.3%,而s1b在NUD和GC中检出率为0.0%。vacA基因m区m1检出率为43.3%（m1a和m1b检出率均为21.7%）和m2检出率为56.7%。vacA基因i区等位基因i1和i2的检出率分别为78.3%和21.7%,i1明显高于i2,可能是胃肠道疾病的主要毒力因子,但与疾病的类型无明显相关性。iceA1和iceA2的阳性率分别为80.0%和16.7%,iceA1/iceA2混合型的阳性率为3.3%。三种毒力基因混合型以cagA+/vacAs1m1i1/iceA1的菌株最多,占总数的31.7%,其次为cagA+/vacAs1m2i1/iceA1,占总数的28.3%。结论 本地区H. pylori毒力因子cagA、vacA和iceA都与胃十二肠疾病的发生密切相关,但与疾病的类型无关。H. pylori毒力基因混合型cagA+/vacAs1m1i1/iceA1和cagA+/vacAs1m2i1/iceA1是胃十二肠疾病疾病中最主要的优势基因型,其分布也与疾病的类型无密切相关性。     

端粒酶活性与幽门螺杆菌相关性胃疾病

端粒酶在胃肿瘤的发生发展中可能具有重要作用,幽门螺杆菌感染与胃肠道疾病的关系密切,且幽门螺杆菌已被列为第一类致癌因子,近年来,一些研究显示了幽门螺杆菌感染与端粒酶活性之间存在一定关系,本文就端粒酶与幽门螺杆菌相关性胃疾病予以综述。     

幽门螺杆菌感染对胃酸及胃液氨浓度的影响

目的 :探讨幽门螺杆菌 (Hp)感染对胃酸分泌及氨浓度的影响以及十二指肠 (DU)的关系。方法 :对DU患者 ,Hp根治前后的胃液pH ,空腹胃酸及氨浓度之间的关系进行研究。结果 :Hp阳性的UC患者其空腹胃酸、氨浓度显著高于正常对照组 (P <0 0 5 ) ,而根除Hp后 ,空腹胃酸显著下降 ,接近正常水平 (P >0 0 5 ) ,氨浓度明显下降。结论 :Hp感染使DU患者胃酸分泌增多 ,二者之间的相互作用在DU的发病中占有重要地位。     

从胃活检组织中分离幽门螺杆菌

比较了不同培养条件和方法对胃活检组织中幽门螺杆菌检出率的影响,从而建立了一种有效的分离培养方法。临床２０例胃活检组织,１４例组织学检查阳性,１０例快速尿素酶和常规尿素酶试验阳性,８例细菌培养阳性,显示此培养方法敏感性５７．１％。     

幽门螺杆菌的致病机理研究进展

本文从幽门螺杆菌（ＨＰ）的流行病学、胃内定居及定居相关因子、胃内生长代谢及代谢产物（包括多种酶和毒素）以及免疫病理等方面综述了近年来对该菌在胃、十二指肠疾病致病机理的研究进展,并提出今后研究方向。     

幽门螺杆菌感染的动物模型及实际应用

幽门螺杆菌已被公认为慢性胃炎、消化性溃疡、胃癌等胃癌的重要病因,但其 致病与免疫机制等多问题的深入解决尚有 待于动物模型的发展。本文好在小猪、犬、猴、裸鼠胃中建立的ＨＰＢ感染模型,或用ＨＰ近似菌如Ｈｅｌｉｃｏｂａｃｔｅｒｆｅｌｉｓ（ＨＦ）或Ｈｅｌｉｃｏｂａｃｔｅｒｍｕｓｔｅｌａｓ（ＨＭ）在小鼠、雪貂胃中建立的拟ＨＰ感染模型,并介绍了它们在观察抗ＨＰ疗法疗效、ＨＰ及其近似菌致病及免疫机制研究中的应用     

幽门螺杆菌——胃的亲密敌人

一个细菌的传奇幽门螺杆菌(Helicobacterpylori)是人类最古老、也是最亲密的"同伴"之一,然而科学家却花了一个多世纪才认清它们。幽门螺杆菌是一种革兰氏阴性杆菌,对人类"情有独钟",是目前所知能够在人胃中生存的惟一微生物种类。幽门螺杆菌外形常常为 S 一个细菌的传奇幽门螺杆菌(Helicobacterpylori)是人类最古老、也是最亲密的"同伴"之一,然而科学家却花了一个多世纪才认清它们。幽门螺杆菌是一种革兰氏阴性杆菌,对人类"情有独钟",是目前所知能够在人胃中生存的惟一微生物种类。幽门螺杆菌外形常常为 S形或弧形,体长为3微米,宽为0.5微米;菌体一端长有几根长约3～5微米的鞭毛,这些鞭毛可以使细菌方便地穿过胃黏膜而定居至胃上皮细胞。幽门螺杆菌有一项特殊的本领,它们能产生大量尿素酶,尿素酶经过分解之后在菌体周围形成一团碱性的"氨云",以此抵抗胃中的强酸,免被胃酸杀死。幽门螺杆菌在世界不同种族、不同地区的人群中均有感染,可以说是成年人中存在最广泛的慢性细菌。在人群中存在的总趋势是感染率随年龄增加而上升,男性略高于女性。它的主要传播途径是人与人的直接或间接接触,发展中国家感染率约为80%,发达国家约为40%。我国的感染年龄早于发达国家20年左右,20～40岁感染率为45.4%～63.6%,70岁以上高达78.9%。另外,我     

幽门螺杆菌

幽门螺杆菌与胃十二指肠病关系的研究已取得显著进展,从而根本改变了我们地慢性胃炎和溃疡病的病因、诊断和防治方面的传统观念。本文对幽门螺杆菌的生物学性状、微生物学检查,致病性,感染治疗等方面进行了论述。     

幽门螺杆菌感染的诊断和治疗

本文阐述幽门螺杆菌（ＨＰ）在消化性溃疡病中的作用以及ＨＰ感染的诊断和治疗,着重介绍清除ＨＰ的一些药物及治疗方案。     

Conservation of the cytotoxin-associated (cag A) gene of Helicobacter pylori and investigation of association with vacuolating-cytotoxin activity and gastroduodenal disease

Abstract Polymerase chain reaction (PCR) amplification and DNA hybridization analyses were used to test for the presence of the cytotoxin-associated ( cag A) gene in 108 strains of Helicobacter pylori . Fifty-two geographically diverse strains of known vacuolating cytotoxin activity, and 56 recent UK clinical isolates from patients with duodenal ulceration ( n =28) and from healthy individuals who were endoscopically normal ( n =28) were studied. Overall, cag A was detected by PCR in 74 (69%) strains and DNA hybridization provided evidence of gene homologues in a further eight strains. For 96% of the cytotoxin-producing strains and 46% of the non-cytotoxin producing strains, there was a close association either with presence or absence of cag A. At the genomic level, Southern blot DNA hybridization showed that cag A was probably present in a single copy in most of the H. pylori tested, and that Hae III restriction site variation within and around the gene provided additional markers of diversity for the species. As 40% of the cag A containing strains did notnproduce an active cytotoxin, and no significant association between cag A presence and DU-disease was observed, we concluded that the presence of the cag A gene in H. pylori could not be used as a single reliable predictor of higher risk patients.     

三联疗法抗幽门螺杆菌感染对儿童肠道菌群状态的影响

目的　探讨抗幽门螺杆菌治疗对儿童肠道菌群状态的影响。方法　分别称取18例幽门螺杆菌感染儿童治疗前后新鲜粪便1.0 g,对肠道菌群中最有代表性的3种需氧菌(肠杆菌、肠球菌和酵母菌)和4种厌氧菌(双歧杆菌、乳杆菌、类杆菌和产气荚膜梭菌) ,分别进行需氧和厌氧培养,菌落计数,同时计算B/ E值来代表定植抗力。结果　抗Hp治疗后,双歧杆菌、乳杆菌和类杆菌较治疗前明显降低( P<0 .0 5 ) ,B/ E值明显下降( P<0 .0 1) ,肠杆菌数量明显增加( P<0 .0 5 ) ,酵母菌的检出率明显增加( P<0 .0 5 )。结论　三联疗法抗Hp治疗对儿童肠道菌群产生明显的影响,因此在治疗Hp感染时须考虑到大量抗生素治疗后可能对患儿产生的副作用及潜在的危险     

Treatment of Helicobacter pylori Infection

This article aims to examine current best practice in the field reference to first-line, second-line, rescue and emerging treatment regimens for Helicobater pylori eradication. The recommended first-line treatment in published guidelines in Europe and North American is proton pump inhibitor combined with amoxicillin and clarithromycin being the favoured regimen. Rates of eradication with this regimen however are falling alarmingly due to a combination of antibiotic resistance and poor compliance with therapy. Bismuth based quadruple therapies and levofloxacin based regimes have been shown to be effective second line regimens. Third-line options include regimes based on rifabutin or furazolidone, but susceptibility testing is the most rational option here, but is currently not used widely enough. Sequential therapy is promising but needs further study and validation outside of Italy. Although the success of first line treatments is falling, if compliance is good and a clear treatment paradigm adhered to, almost universal eradication rates can still be achieved. If compliance is not achievable, the problem of antibiotic resistance will continue to beset any combination of drugs used for H. pylori eradication.     

Helicobacter pylori Reinfection in Brazilian Patients with Peptic Ulcer Disease: A 5-Year Follow-Up

Background:  The Helicobacter pylori reinfection seems to be higher in developing countries, than in developed ones. The aim of the study was to determine the annual recurrence rate of H. pylori , in Brazilian patients with peptic ulcer disease, in a 5-year follow-up.
Methods:  Patients, with peptic ulcer disease diagnosed by upper digestive endoscopy (UDE) and H. pylori infection verified by histological analysis, rapid urease test, polymerase chain reaction, and urea breath test (UBT), were treated for bacterial eradication. The cure of the infection was verified using the same tests, 3 months after. Clinical evaluation and UBT were performed after sixth and ninth month. After 1 year of follow-up, UBT and UDE were repeated. Up to the fifth year, patients were assessed twice a year and an UBT was performed annually. The patients included and all the reinfected were tested for 15 different genes of the H. pylori .
Results:  One hundred and forty-seven patients were followed: 19 for 1 year, eight for 2 years, four for 3 years, five for 4 years, and 98 for 5 years, totaling 557 patients/years. Recurrence did not occur in the first year. In the second year, two patients were reinfected; in the third, four patients; in the fourth, three patients; and in the fifth, one patient. The total of reinfected patients was 10. The annual reinfection rate was 1.8%.
Conclusion:  Brazil presents a low prevalence of H. pylori reinfection, similar to the developed countries.     

Susceptibility in vitro of Helicobacter pylori to cetylpyridinium chloride

The antimicrobial agent cetylpyridinium chloride (CPC) which is used in therapy of oro-pharyngeal infections and for antiseptic treatment of the oral cavity is active against different bacterial species. Determination of the minimal inhibitory concentration (MIC) using the agar dilution technique revealed that the gastric pathogen Helicobacter pylori in vitro is highly susceptible to CPC as indicated by an MIC of 10 microM (3.4 microg ml(-1)) which was significantly lower than the MIC of CPC against other bacterial species, which were analyzed in comparison to H. pylori. Bacteria of the genus Campylobacter, various Streptococcus spp., Staphylococcus aureus and Escherichia coli showed higher MICs ranging from 100 microM to 2 mM. In summary, this finding renders CPC-containing drugs candidates possibly useful for eradication or for the prevention of transmission of the gastric pathogen.     

Helicobacter pylori and Non-malignant Diseases

In 2007 Helicobacter pylori research continued to deal with some controversies raised in the last decade. The main problems remain unsolved: peptic ulcer disease negative for H. pylori , synergism of H. pylori infection and aspirin and other nonsteroidal anti-inflammatory drugs or cyclooxygenase 2 specific inhibitors, the role of H. pylori eradication in uninvestigated and nonulcer dyspepsia, and the possible protective effect of H. pylori infection against gastroesophageal reflux disease and its complications such as Barrett's esophagus and adenocarcinoma. The incidence and prevalence of peptic ulcer disease as well as ulcer-related mortality are continuing to decline all over the world. The increasing consumption of anti-inflammatory and antisecretory drugs was not found to change the trend over the last period and therefore H. pylori was considered the key factor in causing ulcer-related mortality. Some progress has been achieved in understanding H. pylori -induced immunological processes, and attack mechanisms, as well as specific pathogenesis in uremic and cirrhotic patients. There is still a lot to learn about the bacterium and host factors related to H. pylori infection and its complications.