Identification of flagellar and associated polypeptides of Helicobacter (formerly Campylobacter) pylori

Flagella of Helicobacter pylori were isolated from intact organisms by shearing and differential centrifugation. Treatment of the flagella with the detergent Triton X-100 removed the flagellar sheath, which was confirmed by electron microscopy, and the remaining naked flagella were shown by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to consist primarily of a single 54 kilodalton (kDa) polypeptide. This was confirmed by immunogold labelling and electron microscopy of detergent treated whole organisms, using a mouse antiserum specific for the 54 kDa polypeptide. Polypeptides solubilised from crude flagellar preparations by detergent treatment were found to have molecular weights of 26, 30, 58, 62, 66 and 80 kDa. These polypeptides are possible components of the flagellar sheath and they may represent outer membrane proteins, based on the assumption that the flagellar sheath is related in composition to the outer membrane of the organism. Analysis and definition of these components of the surface structures of the organism are important in understanding the interaction between the organism and its host in pathogenesis.     

Antibacterial effects of the urushiol component in the sap of the lacquer tree (Rhus verniciflua Stokes) on Helicobacter pylori

Background: Urushiol is a major component of the lacquer tree which has been used as a folk remedy for the relief of abdominal discomfort in Korea. The aim of this study was to evaluate the antibacterial effects of the urushiol on Helicobacter pylori. Materials and Methods: Monomer and 2–4 polymer urushiol were used. In the in vitro study, pH‐ and concentration‐dependent antibacterial activity of the urushiol against H. pylori were investigated. In addition, the serial morphological effects of urushiol on H. pylori were examined by electron microscopy. In vivo animal study was performed for the safety, eradication rate, and the effect on gastritis of urushiol. The expression of pro‐inflammatory cytokines was checked. Results: All strains survived within a pH 6.0–9.0. The minimal inhibitory concentrations of the extract against strains ranged 0.064–0.256 mg/mL. Urushiol caused separation of the membrane and lysis of H. pylori within 10 minutes. Urushiol (0.128 mg/mL × 7 days) did not cause complications on mice. The eradication rates were 33% in the urushiol monotherapy, 75% in the triple therapy (omeprazole + clarithromycin + metronidazole), and 100% in the urushiol + triple therapy, respectively. H. pylori‐induced gastritis was not changed by urushiol but reduced by eradication. Only the expression of interleukin‐1β in the gastric tissue was significantly increased by H. pylori infection and reduced by the urushiol and H. pylori eradication (p = .014). Conclusions: The urushiol has an antibacterial effect against H. pylori infection and can be used safely for H. pylori eradication in a mouse model.     

幽门螺杆菌空泡毒素研究进展

幽门螺杆菌空泡毒素是该菌产生的已知其它细菌毒素无明显源性的唯一蛋白毒素。该毒素是幽门螺杆菌重要的毒力致病因子,它的产生与感染胃肠上皮损伤和溃疡形成密切相关。本就幽门螺杆菌空泡毒素的结构与功能研究进展以及在未来免疫预防与免疫治疗中的作用进行了阐述。     

Micronutrients (Other than iron) and Helicobacter pylori infection: a systematic review

Background: Many micronutrients depend on a healthy stomach for absorption. Helicobacter pylori chronic gastritis may alter gastric physiology affecting homeostasis of vitamins and minerals. Objectives: Systematic review to assess whether H. pylori infection is associated with reduced micronutrient levels (other than iron) in the plasma or gastric juice and whether low micronutrient levels are modified by eradication treatment. Method: Medline was searched for relevant publications from inception to June 2010. Studies describing micronutrient levels in H. pylori‐infected and not‐infected adults and/or the effect of eradication treatment on micronutrient levels were included. Findings: Fifty‐two publications were selected: 46 investigated the association between H. pylori infection and reduced micronutrient levels and 14 the effect of eradication treatment on micronutrient levels. Sixty‐four studies investigated vitamins (23 ascorbic acid, four ß‐carotene, 21 cobalamin, 11 folate, and five α‐tocopherol) and 10 addressed minerals (one calcium, one copper, one magnesium, one phosphorus, three selenium, and three zinc). Pooled standardized mean differences in micronutrient levels showed positive associations with H. pylori infection for ascorbic acid (gastric juice, ?1.087) and cobalamin (?0.744), and a positive effect of eradication treatment, which increased ascorbic acid in the gastric juice (?1.408) and serum cobalamin (?1.910). No significant association between infection and low folate levels was observed. Meta‐analyses for other micronutrients were not performed owing to insufficient data. Conclusions: Meta‐analyses indicate that H. pylori infection is associated with reduced levels of ascorbic acid and cobalamin, supported by the positive effect of eradication treatment. For other micronutrients, further studies are needed.     

Identification and molecular analysis of superoxide dismutase isoforms in Helicobacter pylori

Three electromorphs of iron superoxide dismutase (FeSOD) were identified among 29 Helicobacter pylori isolates by native gel electrophoresis and activity staining. The electromorphs designated isoforms A, B, and C are characterized by slow, intermediate and fast electrophoretic migration, respectively, which was not observed under denaturing conditions. The isoforms were not associated with virulence determinants and with the outcome of disease. Sequence analysis of the sodB gene in strains producing different FeSOD isoforms and comparison of deduced protein sequences revealed that differences in the electric migration behavior are associated with exchange of charged amino acids, suggesting that faster migration is caused by a more negative total charge of the proteins. Electrophoretic migration of native FeSOD was not influenced by changes in the iron cofactor concentration, oxidative stress, and different media, indicating that FeSOD isoforms represent stable strain-specific markers.     

幽门螺杆菌动物模型研究进展

幽门螺杆菌动物模型用于HP相关疾病和HP疫苗作用的研究。常规实验动物包括悉生猪、悉生狗、非人类灵长动物、猫、雪貂、小鼠、大鼠、沙鼠等。猫螺杆菌和雪貂螺杆菌感染也被用于模型研究。最近,转基因小鼠和基因敲除小鼠也被用作幽门螺杆菌动物模型研究。     

Characteristics of Helicobacter pylori natural transformation

For Helicobacter pylori, which exhibits substantial genetic diversity, many strains are naturally competent for transformation by exogenous DNA. To better understand the mechanism of natural transformation and its role in the generation of diversity, we sought to systematically identify factors important for natural transformation in H. pylori. We now show that the highest frequency of H. pylori transformation occurs when DNA is introduced prior to exponential phase growth, and that it is a saturable phenomenon. That transformation can be inhibited by DNA from Helicobacter (H. pylori and Helicobacter bilis) but not Escherichia coli suggests specificity based on DNA source. Finally, the cag island was determined to be unnecessary for high-frequency transformation.     

Immunological properties of the cell surface haemagglutinins (sHAs) of Helicobacter pylori strain NCTC 11637

Abstract Rabbits were immunised with stage 1 and stage 2 soluble haemagglutinins (sHA) of Helicobacter pylori strain NCTC 11637 and with rabbit erythrocytes coated with stage 1 sHA. After adsorption of stage 1 sHA on erythrocytes, SDS-PAGE analysis showed that 4 major protein bands were removed from the preparation. The anti-sHA coated erythrocyte serum had the highest HA inhibition titre of 16. Crossed immunoelectrophoresis of the stage 1 sHA, against stage 1 and 2 antisera showed multiple precipitin arcs; however, the anti-sHA coated erythrocyte serum produced only two arcs. One arc produced by the anti-stage 2 serum was absent with the anti-stage 1 serum. This arc could have been produced against a 20 kDa polypeptide which was absent in the stage 1 sHA. The other arc was stronger when compared with that produced by anti-stage 1 serum. These two arcs corresponded to the two arcs produced by the anti-sHA coated erythrocyte serum, which had the highest inhibition titre. The two arcs were markedly reduced in crossed immunoelectrophoresis with an adsorbed stage 1 sHA preparation, which indicates that these arcs were produced against the sHAs.     

The effect of Helicobacter pylori infection and dietary iron deficiency on host iron homeostasis: a study in mice

BACKGROUND: Helicobacter pylori, which requires iron to survive, may cause host iron deficiency by directly competing with the host for available iron or by impairing iron uptake as a consequence of atrophy-associated gastric hypochlorhydria. The aim of this study was to examine the effect of H. pylori infection and dietary iron deficiency on host iron homeostasis in a mouse model. MATERIALS AND METHODS: H. pylori SS1-infected and uninfected C57BL/6 mice, fed either a normal diet or an iron-deficient diet, were assessed for iron status and infection-associated gastritis over a 30-week period. RESULTS: After 10 weeks, serum ferritin values were higher in H. pylori-infected mice than in uninfected controls, irrespective of dietary iron intake (p = .04). The infection-related increase in body iron stores persisted in the iron-replete mice but diminished over time in mice with restricted dietary iron intake (p < .0001). At 30 weeks serum ferritin levels were lower in these animals (p = .063). No significant difference in bacterial numbers was detected at the 30-week time point (p > .05) and the histological changes observed were consistently associated with infection (p < .01) and not with the iron status of the mice (p = .771). CONCLUSIONS: Infection with H. pylori did not cause iron deficiency in iron-replete mice. However, diminished iron stores in mice as a result of limited dietary iron intake were further lowered by concurrent infection, thus indicating that H. pylori competes successfully with the host for available iron.     

幽门螺杆菌基因组特征及研究进展

幽门螺杆菌是胃相关疾病：慢性胃炎、消化性溃疡、胃癌和MALT淋巴瘤的一个重要的病原体。其毒力因子包括：尿素酶、鞭毛蛋白、粘附素、细胞毒素相关蛋白和空泡毒素等,通过对全基因序列分析研究,对幽门螺杆菌的致病机制有了进一步的了解。     

Organ-specific autoantibodies in children with Helicobacter pylori infection

BACKGROUND: We compared the prevalence of organ-specific autoantibodies in a group of Helicobacter pylori infected children and a group of uninfected children and investigated the relationship between the presence of relevant autoantibodies and the status of the target organs. PATIENTS AND METHODS: One hundred and twenty-four children with dyspepsia (54 boys, 70 girls; mean age 10.5 years; range 4-19) underwent gastroscopy: 56 had H. pylori infection (31 girls, 25 boys), while 68 (37 girls and 31 boys), were H. pylori-negative. All sera were tested for the presence of: parietal cell autoantibodies (PCA), intrinsic factor autoantibodies (IFA), microsomial autoantibodies, thyroglobulin autoantibodies, islet cell autoantibodies, glutamic acid decarboxylase autoantibodies, adrenal cortex autoantibodies, steroid-producing cell autoantibodies; gastrin, pepsinogen A, pepsinogen C and anti-H. pylori antibodies. The histological features and the ureA and cagA genes were also considered. RESULTS: The frequency of organ-specific autoantibodies was higher in patients with H. pylori infection than in uninfected patients (chi2-test p < .0001). Specifically gastric autoantibodies were significantly higher: seven of the 56 H. pylori-positive children were PCA-positive and one was IFA-positive (chi2-test p = .0004). The presence of autoantibodies was not associated with any clinical or biohumoral signs of disease. CONCLUSIONS: Our study detected a relationship between H. pylori infection in childhood and the presence of organ-specific autoantibodies unassociated with any clinical or biohumoral signs of disease. Helicobacter pylori infection in childhood could trigger the onset of clinical autoimmune gastritis, and/or other clinical autoimmune diseases.     

幽门螺杆菌热休克蛋白70基因的克隆与表达

从幽门螺杆菌染色体ＤＮＡ,用ＰＣＲ方法扩增得到了热休克蛋白７０基因。序列分析表明,我国Ｈｐ临床分离株Ｙ２的热休克蛋白７０基因与经全基因组序列测定的两株幽门螺杆菌２６６９５和ｊ９９有高度同源性。将该基因克性到融合分泌表达载体ｐＭＡＬ－ｐ２中,转化大肠杆菌,在ＩＰＴＧ诱导下表达出与预期大小相符的１１３ｋＤ的融合表达蛋白。该蛋白质３０℃诱导表达５ｈ后,可达到细菌周质总蛋白质的１９．４％。用免疫印迹分析表     

Helicobacter pylori cagA Gene Polymorphism Affects the Total Antioxidant Capacity of Human Saliva

Background:  We aimed to evaluate the total antioxidant capacity (TAC) of saliva in healthy Helicobacter pylori -positive and negative saliva individuals.
Materials and Methods:  A total of 102 human saliva samples were checked for the presence of H. pylori DNA ( ureA and cagA gene fragments).
TAC of saliva was estimated by ABTS radical cation (ABTS^{• +} ) decolorization assay.
Results:  PCR analysis revealed that 36 subjects were ureA-/cagA- , 24 were ureA+/cagA- and 42 were ureA+/cagA+ . Smoking habits had no evident effect on H. pylori infection.
We found that TAC of the ureA-/cagA- material, after 10 seconds reaction reflecting fast-reacting antioxidants, was significantly higher than of ureA+/cagA- and ureA+/cagA+ samples (p < .01 and p < .001, respectively). Similar results were obtained for reaction time of 3 minutes measuring slow-reacting antioxidants (p < .001). We also estimated ureA+/cagA- and ureA+/cagA+ samples alone and reported a statistically significant decrease in the TAC_3min value of ureA+/cagA+ compared with ureA+/cagA- samples (p < .05).
Conclusions:  Our data demonstrated that altered redox equilibrium may be associated with more frequent occurrence of H. pylori in the saliva samples.     

Helicobacter pylori Infection in Children

The review summarizes the articles published on Helicobacter pylori in children between April 2007 and March 2008. Evidence is emerging in different populations including developing countries that the prevalence of H. pylori is declining in all age groups. The reasons for this are unclear but it is unlikely that treatment of infection or improvement in socioeconomic conditions fully explains the decline. For the first time, differences in the inflammatory response between adults and children have been well characterized in a group of adults and children from Chile with similar levels of H. pylori infection. This study suggests that the reduced inflammatory response to H. pylori at a cellular level in children could be the consequence of an enhanced Treg cell response, which in turn down-regulates H. pylori -induced inflammation. The publication of the Paediatric European Register for Treatment of Helicobacter pylori study (PERTH) is important as it demonstrates the advantages of different centers working in collaboration for the benefit of children. It also highlights the fact that while bismuth-based treatment is more effective than proton pump inhibitor-based treatment in children, bismuth preparations are not widely available for use in children.     

Helicobacter pylori associated with glossitis and halitosis

BACKGROUND: Helicobacter pylori is a curved microaerophilic Gram-negative bacterium considered as a risk factor for gastric cancer. The aim of this study was to find an association between burning sensations, acid taste, halitosis, and lingual hyperplasia with the effect of H. pylori on the mouth. MATERIALS AND METHODS: A total of 124 subjects with different gastric diseases were studied: 46 patients with burning, halitosis and lingual dorsum hyperplasia and 78 patients with other diseases. RESULTS: The detection of H. pylori in the oral cavity by histopathologic diagnosis and molecular biology was confirmed in 40/46 (87%) patients with burning, halitosis, and lingual hyperplasia, and in 2/78 (2.6%) subjects with other diseases. Chi2: 91.26 (p < .001) Mantel-Haenszel. CONCLUSION: This trial showed an association between H. pylori and burning, halitosis, and lingual hyperplasia, and further considered this bacterium a risk factor for gastric infection.     

益生菌在幽门螺杆菌根除治疗中的应用

幽门螺杆菌(Helicobacter pylori,H.pylori)是导致活动性胃炎、消化性溃疡、胃癌、胃黏膜相关淋巴组织淋巴瘤等消化系统疾病的重要病因之一,已被世界卫生组织确认为Ⅰ类致癌因子,根除H.pylori对防治上述疾病有重要意义。目前临床上主要采用含抗生素的三联或四联药物进行H.pylori的根除,虽然取得一定的疗效,但随着抗生素耐药率逐年增加,根除率持续下降,限制了其广泛应用。此外,初次或多次治疗失败后再治疗可选择的药物很少。近年来人们开始尝试将益生菌应用在H.pylori根除治疗中,并取得一定疗效。本文就益生菌在辅助根除幽门螺杆菌方面的研究进展作一简单综述。