In vitro subcultures of bacteria can lead to genetic and phenotypic changes. This study aimed at investigating the effect of repeated subcultures on the adhesion, motility, cytotoxicity, and gastric inflammation caused by Helicobacter pylori. H.pylori SS1 strain was subcultured 64 times on agar plates containing Brucella broth and 5% bovine calf serum. The adhesion, motility, cytotoxicity, and gastric inflammation produced in Mongolian gerbils were compared between the first and 64th subcultured strain. The adhesion rates, following 3 hr exposure of AGS cells to either the first strain or the 64th-transferred strain, were 21% and 12%, respectively. The motility of the 64th-transferred strain decreased significantly when compared to the 1st strain (9.1 mm vs. 15.1 mm). The cytotoxicity index tended to be higher in the first strain than in the 64th-transferred strain (73.7% vs. 69.2%). The initial infection rate on the gerbils showed no difference between the two strains. However, chronic gastric inflammation of the first strain-infected gerbils was somewhat more severe than that of the 64th-transferred strain-infected gerbils. Therefore, the use of repeatedly subcultured strains of H. pylori in virulence experiments can lead to different results from thoses of the original strain.
Animals ; Bacterial Adhesion ; Gastritis/immunology/*microbiology ; Gerbillinae ; Helicobacter Infections/immunology/*microbiology ; Helicobacter pylori/growth & development/*pathogenicity ; Male ; Virulence

OBJECTIVES: The significance of the coccoid forms of H. pylori is still controversial and the questions of whether these forms are viable and infective or degenerative are still open. We induced conversion from rod to coccoid forms and studied morphological changes and antigenic evolutions during this conversion and, thereby, elucidated the viability of coccoid forms. METHODS: The H. pylori strain (C001) used for Western blotting was isolated from the patient with gastric cancer. The antigenic evolution during coccoid conversion of H. pylori was studied by Western blotting, using different sera from thirty patients known to be culture positive. These sera were used to reveal the total antigens of the strain cultured for 2 days (100% rod) and 15 days (> 99% coccoid). After SDS-PAGE, with 10% separating gel of total antigens (rod and coccoid), transblotting (Trans-Blot electrophoretic cell, Bio-Rad) was taken onto a nitrocellulose membrane (Bio-Rad). Then, the blots, with human sera diluted at 1/100, were developed with color reaction by goat serum anti-human IgG with alkaline phosphatase and BCIP. RESULTS: The antigenic profiles were not changed in 46.7% (14/30 cases) and were changed in 53.3% (16/30 cases) during coccoid conversion. Antigenic fractions changed during coccoid conversion were protein band at 120 kDa and band at 35 kDa, and were not detected in coccus forms. The rest of the profiles were identical between rod and coccoid forms. The protein which disappeared include CagA (120 kDa) and porin, or adhesin (35 kDa). The morphological changes during coccoid conversion were U shaped at day 7, doughnut shaped at day 9 and full coccoid at day 15. CONCLUSIONS: The results showed that coccoid forms of H. pylori retain cellular structures similar to rod form, and some of the antigens (CagA and porin) disappeared during coccoid conversion. Therefore, coccoid form might be viable and represent one of the stages of H. pylori biological cycle.
Adaptation, Physiological ; Antigens, Bacterial/isolation & purification* ; Gastritis/microbiology ; Helicobacter Infections/microbiology ; Helicobacter pylori/ultrastructure* ; Helicobacter pylori/immunology* ; Helicobacter pylori/growth & development ; Human ; Microscopy, Electron ; Stomach Neoplasms/microbiology ; Virulence

OBJECTIVETo evaluate the accuracy of the Helicobacter pylori (H. pylori) stool antigen (HpSA) test and ImmunoCard STAT HpSA in the primary diagnosis of H. pylori infection.

METHODSWe searched Medline (1966-2007.4), EMbase (1985-2007.4), Chinese Journals Full-text Database (CJFD) (1994-2007) etc. to identify Clinical Trials of ImmunoCard STAT HpSA for the primary diagnosis of H. pylori infection. Meta-analysis was conducted using the method recommended by The Cochrane Collaboration Center.

RESULTSEleven trials were included with pooled sensitivity, pooled specificity as 0.93 (95% CI: 0.91-0.94), 0.93 (95% CI: 0.90- 0.95), respectively. Pooled positive likelihood ratio and pooled negative likelihood ratio were 12.01 (95% CI: 8.90-16.19), 0.08 (95% CI: 0.07-0.11), respectively with the pooled diagnostic odds ratio as 160.14(95% CI :100.43-255.34). The area under the summary receiver operating characteristic (SROC) was 0.974 +/- 0.005.

CONCLUSIONImmunoCard STAT HpSA appeared to be an accurate non-invasive method for the initial diagnosis of H. pylori infection.

Antigens, Bacterial ; immunology ; Feces ; microbiology ; Helicobacter Infections ; diagnosis ; immunology ; Helicobacter pylori ; immunology ; isolation & purification ; pathogenicity ; Reagent Kits, Diagnostic ; Sensitivity and Specificity

ObjectiveGastroscopy combined with gastric mucosa biopsies is currently regarded as a gold standard for diagnosis of gastric cancer. However, its application is restricted in clinical practice due to its invasive property. A new noninvasive population screening process combining the assay of anti-Helicobacter pylori antibody and serum pepsinogen (PG) (ABC method) is adopted to recognize the high-risk patients for further endoscopy examination, avoiding the unnecessary gastroscopy for most population and saving the cost consumption for mass screening annually. Nevertheless, controversies exist for the grouping of ABC method and the intervals of gastroscopy surveillance for each group. In this review, we summarized these popular concerned topics for providing useful references to the healthcare practitioner in clinical practice.

Data SourcesThe PubMed databases were systematically searched from the inception dates to November 22, 2017, using the keywords "Helicobacter pylori," "Pepsinogens," and "Stomach Neoplasms."

Study SelectionOriginal articles and reviews on the topics were selected.

ResultsAnti-H. pylori antibody and serum PG concentration showed significant changes under the different status of H. pylori infection and the progression of atrophic gastritis, which can be used for risk stratification of gastric cancer in clinic. In addition, anti-H. pylori antibody titer can be used for further risk stratification of gastric cancer contributing to determine better endoscopy surveillance interval.

ConclusionsThe early detection and diagnosis of gastric cancer benefit from the risk stratification, but the cutoff values for H. pylori antibody and serum PG concentration require further modification.

Antibodies, Bacterial ; blood ; immunology ; Gastroscopy ; Helicobacter Infections ; blood ; immunology ; Helicobacter pylori ; immunology ; Humans ; Mass Screening ; methods ; Stomach Neoplasms ; blood ; microbiology

OBJECTIVETo determine the distributions of six Helicobacter pylori (Hp)-specific antibodies in a high-risk population of gastric cancer (GC) and explore the relationship between Hp virulence factors and precancerous gastric lesions.

METHODSBased on the two intervention trials conducted in Linqu County, the seropositivities for CagA, VacA, GroEL, UreA, HcpC and GGT were assessed by recombinant immunoassay (recomLine) in 623 participants with H. pylori infection determined by (13)C-urea breath test ((13)C-UBT) and/or enzyme linked immunosorbent assay (ELISA).

RESULTSIn a total of 623 participants were detected by recomLine analysis, of which 594 were Hp-positive. The seropositivities rates of CagA, VacA, GroEL, UreA, HcpC and GGT were 84.0%, 38.2%, 66.7%, 17.7%, 58.8% and 42.8%, respectively. A total of 523 participants were determined as type I infection of Hp, accounting for 88.1%. Compared with superficial gastritis (SG), the infection rate of Hp type I was higher in the chronic atrophic gastritis (CAG) (P = 0.001).

CONCLUSIONSThe results of this population-based study suggest that the virulence factors of Hp may be related to the development of GC in a Chinese high-risk population. The recomLine analysis may serve as a tool for identification of Hp strains and prediction of high-risk population of GC.

Adult ; Antibodies, Bacterial ; blood ; Female ; Gastritis ; blood ; immunology ; microbiology ; Gastritis, Atrophic ; blood ; immunology ; microbiology ; Helicobacter Infections ; blood ; immunology ; Helicobacter pylori ; Humans ; Male ; Middle Aged ; Precancerous Conditions ; blood ; immunology ; microbiology ; Stomach Neoplasms ; blood ; immunology ; microbiology

BACKGROUND/AIMS: This study was designed to investigate the role of gastric acid in the extent of H. pylori-induced gastritis. METHODS: Twenty eight mice were innoculated with live H. pylori. They were allocated into four groups. Mice in group I received no treatment, group II mice were treated with sham injection, group III received 125microgram/kg body weight of pentagastrin, while group IV received 250microgram/kg body weight of pentagastrin subcutaneously three times a week. After 7 months, the mucosal pH, H. pylori density, neutrophils and monocytes infiltration, and the degree of atrophy were assessed in the stomach. RESULTS: In the gastric body, the densities of H. pylori were not different among groups. The degree of neutrophil infiltration was significantly lower in group IV compared to other groups (p<0.05). The degree of monocyte infiltration was also significantly lower in group IV than group III (p<0.05). In the gastric antrum, there was no significant difference of the H. pylori density, neutrophil and monocyte infiltration, and degree of atrophy among the groups. The mice with the gastric mucosal pH lower than mean of 3.2 had significant lower level of H. pylori density (1.4 vs. 2.4, p=0.04), and infiltration of neutrophils (0.9 vs. 2.3, p=0.018), and monocytes (1.2 vs. 1.8; p=0.011) than the those with mucosal pH above 3.2 in the body of stomach. CONCLUSIONS: Gastric acid plays a role in suppressing the proximal propagation of H. pylori-induced gastritis to the body of stomach.
Animals ; Female ; Gastric Acid/*metabolism ; Gastric Mucosa/pathology ; Gastritis/immunology/*microbiology ; Helicobacter Infections/*immunology/microbiology ; *Helicobacter pylori/isolation & purification ; Hydrogen-Ion Concentration ; Mice ; Mice, Inbred C57BL ; Models, Animal

A serologic test for antibodies is useful for diagnosis of Helicobacter pylori(H.pylori) infection in children. We evaluated the reliability of H.pylori IgG antibody titer in grading the severity of infection in children. We surveyed the sero-prevalence of H.pylori infection in 300 healthy school children (13 to 15 years old). Thirty-four percent(102 of 300 children) were sero-positive for H.pylori. Of the 102 sero-positive children, 70 underwent gastroscopic examination. Ninety percent of sero-positive children(63 of 70 children) were proven to be H.pylori infected. All children with H.pylori infection had histologically proven gastritis, and its severity did not correlate with the IgG antibody titer. Although a serologic test is useful to identify H.pylori infection in children, it can not predict the severity of H.pylori associated gastritis.
Adolescent ; Antibodies, Bacterial/*blood ; Gastritis/diagnosis/immunology/*microbiology ; Helicobacter Infections/diagnosis/*immunology ; Helicobacter pylori/*immunology ; Human ; Immunoglobulin G/*blood ; Support, Non-U.S. Gov't

Helicobacter pylori (H. pylori) has been a major concern as a gastric pathogen with unique features since discovered in the end of the 20th century. Recent data on comparative genome study have revealed that H. pylori has successfully survived with its host though over 58,000 years of evolution and migration from continent to continent. To maintain the symbiotic relationship with human, H. pylori has come up with ways to induce host tolerance as well as exert harmful injuries. Studies about H. pylori have accumulated the knowledge about how the cellular and molecular interactions are controlled and regulated to decide whether the symbiotic relationship is directed to diseases or peaceful mutualism. We reviewed recent literatures and research outcomes about the H. pylori and host interaction in molecular and cellular basis.
Adaptive Immunity ; Epithelial Cells/metabolism/microbiology/pathology ; Helicobacter Infections/immunology/metabolism/*pathology ; Helicobacter pylori/*immunology ; *Host-Pathogen Interactions ; Humans ; Symbiosis ; T-Lymphocytes/immunology/metabolism

OBJECTIVEA systematic meta-analysis was performed to explore the role of cytotoxin-associated gene-A (CagA) seropositive strains of Helicobacter pylori (H. pylori) in the pathogenesis of atherosclerotic diseases. Data sources Data from Medline, EMBASE, CBMdisc, CNKI and the Cochrane Collaboration database were searched. Similar search strategies were applied to each of these databases. Study selection The review was restricted to the case-control studies on infective, chronic virulent CagA strains of H. pylori, involving the risk of ischemic stroke and coronary heart disease, ineligible studies were excluded. Two reviewers independently extracted the data and assessed study quality.

RESULTSTotally 26 case-control studies (11 studies on ischemic stroke and 15 studies on coronary heart disease) were retrieved and considered. The combined data revealed that the chronic seropositive virulent strains of H. pylori infection had a trend of increasing the risk of ischemic strokes and coronary heart diseases, yielding pooled ORs of 2.68 (95% CI: 2.20, 3.27) and 2.11 (95% CI: 1.70, 2.62), respectively. We also performed subgroup analyses, dividing the total population into Caucasian and Chinese subgroups. Through the subgroup analysis, no significant difference was found between the subgroups.

CONCLUSIONSOur results support the hypothesis that CagA-seropositive strains infection is significantly associated with susceptibility to ischemic strokes and coronary heart diseases. The magnitude of the association with atherosclerotic diseases needs to be confirmed by prospective studies and the studies on CagA-seropositive strains eradication are more important.

Antibodies, Bacterial ; blood ; Antigens, Bacterial ; immunology ; Atherosclerosis ; etiology ; pathology ; Bacterial Proteins ; immunology ; Helicobacter Infections ; blood ; complications ; microbiology ; Helicobacter pylori ; immunology ; pathogenicity ; Virulence

Antibodies, Bacterial ; blood ; Antigens, Bacterial ; biosynthesis ; Bacterial Proteins ; biosynthesis ; Carrier Proteins ; biosynthesis ; Gastritis ; microbiology ; Helicobacter Infections ; immunology ; Helicobacter pylori ; immunology ; isolation & purification ; Humans ; Recombinant Proteins ; biosynthesis