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

No abstract available.
Antigens, Bacterial/*analysis ; Feces/*microbiology ; Helicobacter Infections/*diagnosis ; Helicobacter pylori/*isolation & purification ; Humans ; Immunoenzyme Techniques

OBJECTIVETo isolate the wild-type virulent phage of Helicobacter pylori (Hp) and simulate the treatments in vitro to investigate the methods for oral Hp-assisted penetration of the phage through the gastric barrier and offspring phage release for infection and treatment of gastrointestinal Hp.

METHODSThe Hp strain was cultured with the candle cylinder method and the virulent phage was isolated by single plate or double plate experiment. A simulated gastric juice was applied and the bactericidal effect of the phage was tested with double flats experiment.

RESULTSAfter a 1.5-h treatment in simulated gastric juice, the orally derived Hp-borne phage was still capable of forming plaques while the control phage was not.

CONCLUSIONThe oral Hp can help the phage resist the gastric juice and then infect the gastrointestinal Hp.

Bacteriophages ; isolation & purification ; physiology ; Gastrointestinal Tract ; microbiology ; Helicobacter Infections ; therapy ; Helicobacter pylori ; virology ; Humans ; Virulence

The aim of this study was to evaluate whether PCR-based restriction fragment length polymorphism (RFLP) analysis was effective in differentiating between reinfection and recrudescence of H. pylori strains. Following a 1-2 week regimen of omeprazole 20 mg, amoxicillin 1.0 g, and clarithromycin 500 mg twice daily, twenty patients with duodenal ulcer were enrolled in the study. Ten patients (group 1, control) were not successfully treated, and another 10 patients (group 2) exhibited recurrence of infection 6-24 months following the therapy. Follow-up diagnosis was performed by Giemsa stain and CLO test. RFLP profiles of antral and midbody biopsy specimens were compared before and after therapy. PCR products using the ureC gene were digested with restriction enzymes Hha I, Mbo I, and Hind III, and the fragments generated were analyzed by agarose gel electrophoresis. Hha I, Mbo I, and Hind III digestion produced 13, 7, and 2 distinguishable digestion patterns, respectively. There was no difference in RFLP profiles seen before and after the therapy in 17 duodenal ulcer patients, while different RFLP profiles were discovered in 3 patients. Following treatment, one (group 2) patient differed in Mbo I, and two (one each from both groups) patients differed in Hha I and Mbo I RFLP patterns. Eight of group 2 patients showed recrudescence of previous infection and two patients had reinfection by another strain. This study supports the hypothesis that PCR-based RFLP analysis can be effective for differentiating reinfection and recrudescence of H. pylori strains following triple therapy.
Adult ; Female ; Helicobacter Infections/drug therapy ; Helicobacter Infections/diagnosis* ; Helicobacter pylori/isolation & purification* ; Helicobacter pylori/genetics ; Human ; Male ; Polymerase Chain Reaction* ; Polymorphism, Restriction Fragment Length* ; Recurrence

OBJECTIVES: Considering the geographic differences in the prevalence of virulence factors such as CagA or VacA of H. pylori isolated from Korean adults compared with those from western countries, the establishment of a mouse model infected with H. pylori isolated from Korean adults is needed to investigate the pathogenesis and to develop vaccines against H. pylori infection in Korea. The aim of this study was to establish the BALB/c mouse model infected with H. pylori isolated from Korean. METHODS: Six-week-old BALB/c mice were inoculated intragastrically with 10(9) CFU of H. pylori. Loss of glandular architecture, erosions and infiltration of inflammatory cells within the lamina propria compared with normal gastric mucosa were scrutinized. Evidence for H. pylori infection was assessed by rapid urease test of gastric mucosa and by microscopic examination using the H & E stain and Warthin-Starry silver stain. RESULTS: Rapid urease test was positive in 55% of all inoculated mice. Definite histologic changes and the evidence of H. pylori colonization were observed in the H. pylori infected group. Significant infiltration of inflammatory cells was observed 6 weeks after the last inoculation and the level of serum IgG against H. pylori was increased from 2 weeks after the last inoculation. CONCLUSIONS: The H. pylori isolated freshly from Korean adults could colonize the stomach of BALB/c mice and induce pathologic alterations that mimics human gastric diseases. This model would facilitate the investigations for the pathogenetic mechanisms of H. pylori infection.
Adult ; Animal ; Base Sequence ; DNA Primers/genetics ; Disease Models, Animal ; Female ; Gastric Mucosa/pathology ; Helicobacter Infections/pathology ; Helicobacter Infections/etiology* ; Helicobacter pylori*/pathogenicity ; Helicobacter pylori*/isolation & purification ; Helicobacter pylori*/genetics ; Human ; Korea ; Mice ; Mice, Inbred BALB C ; Virulence/genetics

Autoimmune Diseases ; pathology ; Biopsy ; Cytomegalovirus Infections ; pathology ; Gastric Mucosa ; pathology ; virology ; Gastritis ; pathology ; virology ; Helicobacter Infections ; pathology ; Helicobacter heilmannii ; isolation & purification ; Helicobacter pylori ; isolation & purification ; Humans

OBJECTIVEThis study was aimed to characterize the Helicobacter pylori strains isolated from different geographic regions in China and different ethnic groups in Yunnan province in terms of cagA, iceA, vacA and HP0519 genes which were proposed to be related to the pathogenesis.

METHODS150 Helicobacter pylori strains were collected from Yunnan province, Fujian province and Beijing. Chromosome DNA was extracted and polymerase chain reaction (PCR) was carried out to determine the 3' region of cagA, iceA, vacA and HP0519 status with specific primers. PCR results were analyzed statistically according to their isolated original and clinical outcomes.

RESULTSFor cagA 3' region, 93% (139/150) of the Chinese Helicobacter pylori strains belonged to East Asian type according to the specific primer of TF/JR. Among the 150 strains, 75% (113/150) belonged to iceA1, and 19% (29/150) to iceA2. The dissemination of iceA was not associated with any of the geographic regions, different ethnic groups or different clinical outcomes. 96% (144/150) of the vacA s region belonged to s1. In the vacA middle region, m2, m1b, m1b-m2 were 57% (85/150), 27% (41/150) and 11% (16/150) respectively. However, m1a was only observed in two strains from Fujian. Neither vacA s1 nor m2 showed significant difference between Yunnan, Fujian and Beijing. However, the distribution of mlb-m2 in Yunnan was higher than that in Fujian and Beijing. In Yunnan province, the distribution of vacA s1 was not associated with different ethnic groups but m2 from Bai group was less than other two ethnic groups. The ratio of m1b in Bai group was higher than that in other groups. Both vacA' s region and m region alleles had no significant relationship with the clinical outcomes. With the 15 bp and 24 bp DNA insertion and deletion primers test, 93% (140/150) of the strains were positive. The distributions of the 15 bp and 24 bp DNA insertion or deletion were different according to the different ethnic groups.

CONCLUSIONBy JF/TR primer, 93% of the Chinese strains cagA's 3' region belonged to East Asian type. Most of the Chinese strains vacA's allele was s1. The distribution of vacA s1 had no relationship with the clinical outcome of the isolates. From different geographic regions and ethnic groups, the distribution of vacA m region allele was different. 93% of the Chinese strains HP0519 genes had 24 bp or 15 bp insertion or deletion character. The biological meaning of the polymorphism of HP0519 needs advanced investigation.

China ; Genes, Bacterial ; genetics ; Helicobacter Infections ; ethnology ; genetics ; Helicobacter pylori ; classification ; genetics ; isolation & purification ; Humans ; Polymerase Chain Reaction

OBJECTIVETo establish a stable and reliable model of Helicobacter pylori infection in Mongolian gerbil and to observe pathological changes in gastric mucosa from the infected animals.

METHODSMongolian gerbils were randomly divided into six groups infected with H.pylori strain NCTC11637 (n=6, group N), six groups infected with H.pylori clinical strain Y06 (n=6, group Y) and six groups as negative control (n=4, group C). H.pylori suspensions at the concentrations of 2 X 10(8)CFU/ml and 2 X 10(9) CFU/ml of strain NCTC11637 and strain Y06 were prepared with Brucella broth from Columbia agar containing sheet blood. The animals in one group N and in one group Y were orally challenged once with 0.5 ml of 2 X 10(8) CFU/ml H.pylori suspension. The animals in another group N and in another group Y were orally challenged with 0.5 ml of 2 X 10(9) CFU/ml H.pylori suspension for three times at the intervals of 24 hours, respectively. The animals were killed after 2nd, 4th and 6th week of the last infection and the gastric mucosal samples were taken for urease test, bacterial isolation, routine pathological and H.pylori histochemical examinations.

RESULTSInfection rates of the animals in group N and group Y at the 2nd, 4th and 6th week after one challenge were 0%, 0%, 66.7% and 0%, 16.7%, 16.7%, respectively. Infection rates of the animals in groups N and Y at the 2nd, 4th and 6th week after three challenges were 66.7%, 100%, 100% and 66.7%, 66.7%, 100%, respectively. In animals with positive bacterial isolation H.pylori was found to colonized on the surface of gastric mucosal cells and in the gastric pits, and the lamina propria of gastric mucosal was infiltrated with chronic inflammatory cells.

CONCLUSIONBy using H.pylori suspension at high concentration of 1 X 10(9) CFU for multiple times, the orally challenged Mongolian gerbils can be prepared as a stable and reliable H.pylori infection model. H.pylori can colonize in gastric mucosa of the infected animals, and mild inflammation reactions can be seen.

Animals ; Disease Models, Animal ; Female ; Gastric Mucosa ; microbiology ; Gerbillinae ; Helicobacter Infections ; microbiology ; pathology ; Helicobacter pylori ; isolation & purification ; Immunohistochemistry

OBJECTIVEUsing Markov model Monte Carlo simulation to conduct a cost-effectiveness analysis of screening Helicobacter pylori (H. pylori) infection to prevent gastric cancer.

METHODSThe Markov model was developed based on the natural course from H. pylori infection to gastric cancer. Two strategies were compared: (1) screening for H. pylori and treatment for those with positive tests, and (2) without screening and treatment. Data used for model simulation including transition probability, efficacy of test and treatment were collected from related research publications. Markov model Monte Carlo simulation combined with bootstrap method was used to perform base-case analysis and estimate the confidence interval of cost-effectiveness ratios. The probability sensitivity analysis was used to estimate the cost-effectiveness in multiple uncertainty factors.

RESULTSAssuming H. pylori eradication will prevent 50% of attribute gastric cancer, the screening strategies would prevent 16.6% cases of gastric cancer. Cost-effectiveness were 10,405 Yuan (95% CI: 4,238 - 27,727 Yuan) per GC prevented, 64 Yuan (95% CI: 31 - 97 Yuan) per QALY saved and 1,374 Yuan (95% CI: 352 - 86,624 Yuan) per life year saved.

CONCLUSIONScreening and treatment for H. pylori infection in population was potentially effective in the prevention of gastric cancer, and screening in high incidence area of gastric cancer would be more effective and economic.

Cost-Benefit Analysis ; Helicobacter Infections ; complications ; diagnosis ; Helicobacter pylori ; isolation & purification ; Humans ; Markov Chains ; Probability ; Stomach Neoplasms ; prevention & control

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