弯曲菌性胃肠疾患的速筛检及发病机理初探

幽门弯曲菌与胃炎和消化性溃疡关系非常密切。该菌可产大量尿素酶,胃粘膜尿素酶试验可以判定该菌的存在。本文采用快速尿素酶试验,检测了160例有上消化道症状的患者,其中发现96例有该菌,同时测定了60份胃液标本的尿素含量,Cp阴性者尿素浓度为1.01±0.30mmol/L(M SD),阴性则为2.63±0.77mmol/L。结果提示该菌尿素酶活性以及细菌寄居处胃粘膜粘液分泌减少可能是胃肠疾患病变发展过程中的重要因素。     

半巢式PCR技术在幽门螺杆菌检测中的应用

目的采用半巢式PCR方法检测牙菌斑、唾液及胃粘膜幽门螺杆菌(Helicobacter pylori,Hp),以了解口腔中Hp与胃粘膜Hp感染的关系.方法利用半巢式PCR方法(Heminested PCR Assay)扩增磷酸葡萄糖胺变位酶基因(phosphogluco-samlne mutase gene、glmM)内部片段,并对82例慢性胃炎和十二指肠溃疡患者的牙菌斑、唾液及胃粘膜进行检测.结果56例确诊Hp感染的患者中胃粘膜半巢式PCR检测全部阳性,22例(39.3%)牙菌斑Hp阳性,34例(60.7%)唾液Hp阳性;26例胃粘膜Hp阴性的患者中3例(11.5%)牙菌斑Hp阳性,3例(11.5%)唾液Hp阳性.结论Hp不仅存在于胃粘膜组织中,也存在于口腔牙周组织,提示口腔中的Hp可能与胃粘膜中的Hp存在着一定的病因学关系.     

C反应蛋白在胃黏膜、口腔幽门螺旋杆菌感染中的意义

目的探讨胃黏膜及口腔幽门螺旋杆菌(HP)感染与C反应蛋白(CRP)的相关性。方法选择196例HP阳性患者,检测其CRP,然后给予三联抗HP治疗,4周后复查HP、CRP,HP仍阳性患者行幽门螺旋杆菌唾液测试板法(HPS)检查,得到HP阳性及阴性、HSP阳性及阴性4组患者CRP值,将上述结果进行统计分析。结果 HP、HPS阳性患者的CRP水平相比对应阴性患者显著升高,差异有统计学意义(P0.05)。结论 HP感染与血清CRP水平密切相关。     

儿童上消化道疾病与幽门螺旋杆菌之间的关系

目的观察儿童消化性疾病的病理变化及其与HP感染的关系。方法选择60例年龄在14～17岁有反复腹痛、呕吐、吐血、纳差等症状的患儿,通过胃镜检查,观察其消化道形态变化,并取胃粘膜进行病理检测和HP检测,并根据HP检查结果随机分为HP阳性组及HP阴性组。结果 HP阳性胃粘膜炎症反应程度明显严重,于HP阴性组(p<0.05);儿童上消化道疾病与HP关系密切。结论儿童上消化道疾病患儿胃粘膜炎症反应程度与HP感染明显相关。     

杭州地区临床和环境分离副溶血弧菌菌株携带毒力基因的特征

目的　了解杭州地区临床和环境分离副溶血弧菌菌株的毒力基因特征。方法　对近年从食物中毒病人、临床散发病人和外环境 (小水产品 )中分离的 174株副溶血弧菌菌株 ,应用PCR技术进行耐热直接溶血素基因 (tdh)和耐热直接溶血素相关基因 (trh)的检测。结果　临床来源的副溶血弧菌 (94株来自食物中毒病人和 34株来自散发腹泻病人 )菌株的tdh携带率均大于 97% ,trh携带率为 0 % ;而所有 4 6株分离自环境 (小水产品 )的副溶血弧菌菌株未见有tdh携带 ,仅 1株trh阳性。 1株tdh阴性、trh阳性的副溶血菌株 ,其尿素酶试验为阳性 ,而在其他所有trh阴性的副溶血菌株中 ,不管其tdh是阳性或是阴性 ,尿素酶试验均为阴性。结论　引起杭州地区食物中毒及散发腹泻的副溶血弧菌主要为tdh阳性、trh阴性菌株 ,外环境中存在的trh阳性的副溶血弧菌也是一个潜在的病原     

宅蝇幽门螺杆菌DNA的检测

绝大多数个体的幽门螺杆菌(HP)传染源不明,推测由粪-口和口-口方式传播。研究显示,实验室对照蝇能群殖HP,这就表明摄入蝇分泌物污染的食品或蝇直接接触粘膜可引起HP感染。其他研究者,采用初始的PCR和尿素酶试验也证实野生宅蝇存在HPDNA。虽然HP具有相对特异性,但上述初始检测方法,可使野生宅蝇中其他尿素酶阳性细菌DNA也能扩增,为此,采用特异性和敏感性更高的PCR分析技术,检测野生宅蝇(家蝇属)HPDNA异枸橼酸脱氢酶。在农村、农场、城市捕获的野生宅蝇中,检测了HP异枸橼酸脱氢酶基因,结果发现:北美地区97组中有10组HP阳性(每组5…     

生殖道染色技术应用于幽门螺杆菌诊断1 102例

用生殖道染色技术Ⅱ液做胃粘膜HP染色1102例。HP阳性检出率716例占总检人数的64．97％。40例HP阳性病人用生殖道染色技术，快速尿素酶实验、细菌培养三者对比实验。结果相同。生殖道染色技术Ⅱ液对螺杆菌有较强的亲和力，着色鲜艳，操作简便，染色快，费用低，综合集中了银染色、姬姆萨染色、甲苯胺蓝等染色的优点。     

多重PCR技术检测医院感染大肠埃希菌、肺炎克雷伯菌质粒AmpC酶基因型别

目的了解我地区大肠埃希菌、肺炎克雷伯菌携带质粒介导AmpC酶的情况及基因型别. 方法用头孢西丁耐药表型筛选阳性可疑菌株,提取耐药质粒,然后采用多重PCR技术检测是否存在质粒介导的AmpC 基因及其基因型别;并对PCR产物进行测序. 结果 7株头孢西丁耐药的大肠埃希菌多重PCR均为阴性,4株肺炎克雷伯菌中3株多重PCR阳性,测序结果均为DHA-1型质粒AmpC酶. 结论多重PCR技术是一种灵敏、特异、快速的检测质粒AmpC酶及其基因型别的好方法;采用该方法在我地区首次检测出产DHA-1型质粒AmpC酶的肺炎克雷伯菌.     

幽门螺杆菌的分离与特性研究

目的 分离一株幽门螺杆菌，研究它的生物学特性及免疫原性，同时比较几种检测手段的优势。方法 采用厌氧微生物培养技术及PCR检测方法分离、初步鉴定幽门螺杆菌。重点对其中一株菌HP－WGM做各项生理生化实验，ELISA试验分析。结果 从106位患中分离鉴定得到40株疑似幽门螺杆菌。HP－WGM菌株革兰氏染色试验阴性、杆状、稍弯曲、菌体的一端着生数根带鞘鞭毛。该菌脲酶、触酶、氧化酶均为阳性，不还原硝酸盐，H2S的生成试验阴性，基生长耐3．5％NaCl、1％甘氨酸，水解淀粉，不液明胶。该菌有一定的免疫原性。结论 HP－WGM菌株可作为一种抗原用于检测幽门螺杆的感染程度。对于疾病的确诊，应采用至少2种以上以的检测手段，用于科学研究时，细菌培养、鉴定的方法才是最为可靠的手段。     

两种不同方法检测幽门螺杆菌感染的临床比较

目的比较不同检测幽门螺杆菌感染方法，为临床提供一种检测幽门螺杆菌的最佳方案。方法对125例患者分别采用快速血清尿素酶抗体检测法和^13C尿素呼气试验（UBT）检验Hp感染情况，并比较敏感性及特异性等。结果125例检测者中，Hp阳性56例，Hp阴性69例。^13C尿素呼气试验法：真阳性52例，假阳性2例，真阴性66例，假阴性5例；血清尿素酶抗体检测法：真阳性51例，假阳性3例，真阴性65例，假阴性6例。两种方法敏感性、特异性、准确度较高，差异无显著意义（P〉0．05）。结论^13C尿素呼气试验检测易为患者接受，是较理想的检查方法，但因有一定的放射性，还要有特殊的仪器；血清尿素酶抗体检测方法简便、操作简单，无痛苦、无污染，其无创伤性尤其适合儿童检查。     

Evaluation of rapid urease test for detection of Helicobacter pylori in gastric biopsy specimens

Using 80 gastric biopsy specimens from patients with various gastroduodenal diseases, the isolation rate of H. pylori and urease activity of the biopsy specimens were examined. The sensitivity and specificity of the rapid urease test was 84.6% and 75.9%, respectively, for the cultivation of H. pylori. The mean number of H. pylori detected in urease-positive and negative biopsy specimens was 10^{6.1 ± 0.9} and 10^{4.5 ± 1.2} cfu/g specimens, respectively.     

Prevalence of Helicobacter pylori in asymptomatic subjects—A nested PCR based study

The aim of the study was to see the prevalence of Helicobacter pylori in asymptomatic children and adults by using nested PCR which is considered to be more specific than serological methods. Saliva and stool samples of 137 healthy children (aged 8 months to 16 y) and 108 asymptomatic adults (aged 17–60 y) were collected. PCR with primers targeting Hsp60 gene sequence of H. pylori was used. H. pylori positivity with nested PCR was observed in 45.7% (112/245) of the saliva and 42.8% (105/245) of the stool specimens. Prevalence of H. pylori in saliva was found to be 2.1%, 22.7%, 55.9%, 56.0%, 68.9% and 62.9% in the age groups of <5 y, 6–10 y, 11–16 y, 17–30 y, 31–45 y and 45–60 y, respectively. The detection rates in stool were 4.25% in <5 y, 13.64% in 6–10 y, 50% in 11–16 y, 64% in 17–30 y, 58.62% in 31–45 y and 61.1% in 45–60 y of age groups. The most favourable age group for acquiring the infection was 11–16 y. H. pylori positivity increased with lowering of socioeconomic status. There was no gender bias in prevalence of the bacterium.     

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.     

DNA methylation: a marker for carcinogen exposure and cancer risk

Cancers arise as a consequence of multiple genetic and epigenetic alterations. Many genes aberrantly methylated in cancers have been identified in recent years, and their use in cancer diagnosis and therapy is currently under investigation. During our genome-wide screening for a novel tumor-suppressor gene in gastric cancers, we found that only a small amount of aberrant methylation was present, even in non-cancerous gastric mucosae. A subsequent large-scale analysis of the gastric mucosae of healthy individuals and gastric cancer patients using quantitative methylation-specific PCR (qMSP) revealed that Helicobacter pylori infection potently induced aberrant DNA methylation in non-cancerous gastric mucosae and that these high methylation levels can decrease following cessation of the H. pylori infection. Helicobacter pylori infection induced the methylation of specific genes among 48 genes that can be methylated in gastric cancer cell lines. Most importantly, the methylation levels in the gastric mucosae of individuals without H. pylori infection correlated with their risk of gastric cancer. These findings show that a field for cancerization is formed by H. pylori infection and that this field can be measured using DNA methylation as a marker. The concept of an “epigenetic field for cancerization” has been also demonstrated for colon and breast cancers, and it is possibly present for other cancers and other diseases. Applied knowledge of epigenetic changes in human diseases has now started to make an impact on the prevention, diagnostics, and therapeutics of these diseases.     

Plasma ghrelin isoforms and gastric ghrelin O-acyltransferase expression are influenced by Helicobacter pylori status

ObjectiveHelicobacter pylori is known to affect the host’s nutritional status. This study was performed to elucidate the relationship between H. pylori status and the dynamics of the ghrelin system, in the context of ghrelin O-acyltransferase (GOAT) expression.MethodsWe conducted a clinical study of 30 subjects focusing on the following points: 1) the effects of H. pylori infection on the concentrations of circulating ghrelin isoforms and on ghrelin and GOAT mRNA expression in the gastric mucosa, and 2) the effects of H. pylori eradication on the same parameters.ResultsThe plasma acyl-ghrelin and desacyl-ghrelin concentrations of 16 H. pylori positive participants were significantly lower than those of 14 H. pylori negative controls. The acyl-ghrelin/desacyl-ghrelin ratio was not significantly different between the H. pylori positive and H. pylori negative participants. The levels of ghrelin and GOAT mRNA in the gastric mucosa were significantly lower in the H. pylori positive participants than in the H. pylori negative controls. In 11 subjects in whom H. pylori eradication was successful, their plasma acyl-ghrelin levels tended to increase after H. pylori eradication, but the difference was not significant; however, their plasma desacyl-ghrelin levels were significantly reduced. Although gastric ghrelin mRNA expression increased significantly after H. pylori eradication, gastric GOAT mRNA expression tended to increase but was not significantly altered.ConclusionH. pylori status might affect the host’s nutritional status through changes in the plasma levels of ghrelin isoforms and the gastric expression levels of ghrelin and GOAT mRNA.     

Curcumin Inhibits Gastric Inflammation Induced by Helicobacter Pylori Infection in a Mouse Model

Helicobacter pylori (H. pylori) infection triggers a sequence of gastric alterations starting with an inflammation of the gastric mucosa that, in some cases, evolves to gastric cancer. Efficient vaccination has not been achieved, thus it is essential to find alternative therapies, particularly in the nutritional field. The current study evaluated whether curcumin could attenuate inflammation of the gastric mucosa due to H. pylori infection. Twenty-eight C57BL/6 mice, were inoculated with the H. pylori SS1 strain; ten non-infected mice were used as controls. H. pylori infection in live mice was followed-up using a modified ¹³C-Urea Breath Test (¹³C-UBT) and quantitative real-time polymerase chain reaction (PCR). Histologically confirmed, gastritis was observed in 42% of infected non-treated mice at both 6 and 18 weeks post-infection. These mice showed an up-regulation of the expression of inflammatory cytokines and chemokines, as well as of toll-like receptors (TLRs) and MyD88, at both time points. Treatment with curcumin decreased the expression of all these mediators. No inflammation was observed by histology in this group. Curcumin treatment exerted a significant anti-inflammatory effect in H. pylori-infected mucosa, pointing to the promising role of a nutritional approach in the prevention of H. pylori induced deleterious inflammation while the eradication or prevention of colonization by effective vaccine is not available.     

Comparisons between degree of histological gastritis and DNA fingerprints,cytotoxicity and adhesivity of Helicobacter pylori from different gastric sites

Thirty-six isolates of H. pylori from up to three gastric biopsy sites (antrum, corpus and fundus) from 13 patients in Italy with different degrees of histological gastritis were investigated. All strains were tested for motility, cytotoxicity and degree of adhesion, and were typed by analysis of ribosomal RNA gene patterns (ribopatterns). Seventeen different DNA types (ribotypes) were identified, with each patient possessing H. pylori of one or more unique types. Only two patients had identical H. pylori at three sites. Most patients had H. pylori with different ribotypes or subtypes, but nine strains were not typable. Five patients had the same strain colonizing two of the three sites and atypical strains were mostly from the antrum. A complex pattern of H. pylori colonization in the stomach of some individuals was evident and suggested multiple sources of infection. No consistent associations were detected between degree of gastritis and adherence, cytotoxicity and motility but a 2.56Kb rRNA gene fragment that had a higher frequency in strains associated with severe gastritis than mild gastritis, may provide a useful molecular marker for future pathogenicity studies.     

Synergistic effect of anti-Helicobacter pylori urease immunoglobulin Y from egg yolk of immunized hens and Lactobacillus johnsonii No.1088 to inhibit the growth of Helicobacter pylori in vitro and in vivo

Helicobacter pylori is a pathogenic bacterium that infects the stomach, causing chronic gastritis; and it is also considered to be related to the occurrence of gastric cancers. Although some eradication regimens including multiple antibiotics have been developed, the emergence of resistance to antibiotics becomes problematic. Therefore, other approaches to compensate or augment the effects of standard regimens are needed. In this study, we examined the possible synergistic effects of anti-H. pylori urease IgY and Lactobacillus johnsonii No.1088 (LJ88) both in vitro and in vivo. Anti-H. pylori urease IgY was purified from egg yolks laid by the hens immunized with urease purified from H. pylori. LJ88 is a unique strain of lactic acid bacterium isolated from human gastric juice, and it has been reported to inhibit H. pylori both in vitro and in vivo. The in vitro mixed culture study showed that anti-H. pylori urease IgY augmented the anti-H. pylori activity of LJ88 against both clarithromycin-sensitive and -resistant H. pylori strains. In a germ-free mice infection model, combined administration of daily anti-H. pylori urease IgY and weekly living LJ88 significantly reduced H. pylori infections, whereas either monotherapy did not. In an in vivo human gut microbiota-associated mice model, not only daily administration of living LJ88 but also heat-killed one significantly reduced an H. pylori infection in the stomach when combined with anti-H. pylori urease IgY. The extent of reduction of the stomach H. pylori by such a combination therapy was larger than that reported for LJ88 monotherapy. These results taken together revealed a synergistic effect of anti-H. pylori urease IgY and living or heat-killed LJ88, thus suggesting that such a combination might be a promising therapy to possibly compensate and/or augment standard anti-H. pylori regimens.     

Colombia: the widening gap between health care reform and gastric cancer

The purpose of this paper is to discuss Colombia’s recent health care reform and subsequent social implications regarding gastric cancer, which is a common cancer in Colombia. This review explores the use of Helicobacter pylori prevalence classifying as an indicator of failing implementation of health policy, specifically H. pylori should be explored in the context of socioeconomic inequity. A review of the literature examining recent Colombian health care reform and H. pylori infection was conducted. H. pylori occur most frequently in impoverished populations. Gastric cancer (GC) is the main cause of mortality by cancer in Colombia, a South American country, which has a high prevalence of H. pylori in the population. Over the past 40 years, Colombia has undergone a revolutionary improvement in the health and social status of its population. In recent times, the country has faced a unique challenge as its government has grappled with the ongoing civil war with numerous war rebels. It is known that socioeconomic conditions, known to influence gastric cancer risk, are important determinants of H. pylori infection. The role of socioeconomic gradients in developing countries should be emphasized as a basis for etiological research; the disparity between the wealthy and poor is increasing over time. Colombia is currently undergoing major changes in disease-specific mortality rates, including an increasing burden of cancer death.     

Individual hosts carry H. pylori isolates with different cagA features – motifs and copy number

BackgroundH. pylori strains with different genetic contents may infect different or an individual human host. Genetic diversity of cagA is thought to contribute to differences in H. pylori strains pathogenicity. In this study, diversity of cagA genotype, EPIYA motif and copy number was assessed in H. pylori single colonies isolated from individual patients.Materials and methodsGastric biopsies from 14H. pylori-positive dyspeptic patients were cultured on selective brucella blood agar and incubated at 37 °C under microaerobic conditions. Four single colonies were obtained from each biopsy subculture on brucella blood agar under similar incubation condition. Presence of cagA and types of EPIYA motifs was determined by polymerase chain reaction (PCR) and cagA copy number by quantitative real-time (RT) PCR.ResultsSingle colonies of 5 patients showed no variation in cagA genotype, EPIYA motif and copy number. Out of the remaining 9 patients, 1 patient showed presence or absence of cagA gene, 2 patients had mixed EPIYA motifs, 2 patients had different cagA copy number, 1 patient showed absence or presence of cagA and mixed motifs, 2 patients had cagA genes with different nucleotide sequences, 1 patient showed presence or absence of cagA and difference in cagA nucleotide sequence. Four isolates that contained multiple copies of cagA, carried EPIYA-ABC motif.ConclusionGenetic diversity of cagA among single colonies isolated from individual patients represents evidence that gastric mucosa of every individual is colonized with a specific and heterogeneous population of H. pylori. Future studies on patients in different disease groups may elucidate the role of mixed populations of H. pylori in development of gastric diseases.