Signature patterns of DNA restriction fragments of Helicobacter pylori before and after treatment.

The genomic DNA of Helicobacter pylori was studied by electrophoretic analysis of restriction endonuclease fragments. Twenty seven isolates from eight patients in the United Kingdom, obtained before and after treatment with nitrofurantoin, and two reference strains from Australia and Peru were investigated. Digestion of DNA with HaeIII, which gave the clearest band pattern of the 20 enzymes tested, showed that each set of isolates from a single patient had a unique band pattern. The DNA signature band patterns of strains from different patients were less than or equal to 62% similar (average 43%); similarities of patterns from the same patient were generally greater than or equal to 86%. Some minor but reproducible polymorphisms (less than or equal to five bands) in the signature region were detected in most consecutive isolates. Plasmid DNA was detected in isolates from five patients, but major pattern differences were attributed to genomic variation. It is concluded that the HaeIII DNA digest signature fingerprints provide a reproducible and sensitive method of discriminating between isolates of H pylori.     

The normal gastric microflora and Helicobacter pylori; before, during and after treatment with omeprazole and amoxycillin

Objective: To study the microflora in patients with Helicobacter pylori infection during treatment with omeprazole alone and in combination with amoxycillin, to study transmission of relapsing H. pylori strains by fingerprinting and to investigate if H. pylori is detectable in saliva and dental plaque by polymerase chain reaction (PCR).
Methods: Twenty-eight dyspeptic patients with H. pylori infection were divided into two treatment groups omeprazole 20 mg plus amoxycillin 1000 mg, or omeprazole 20 mg plus placebo twice a day for 14 days. Biopsies were taken before, during and after treatment. The biopsies were cultivated in order to study the commensal microflora and H. pylori PCR was used to detect H. pylori in the biopsies, saliva and dental plaque. The H. pylori strains were fingerprinted with arbitrary primed PCR.
Results: Twenty-five patients harbored H. pylori , of whom 22 also harbored a normal mucosal microflora. H. pylori was present in all patients in the omeprazole-placebo group and in 39% of the patients in the omeprazole-amoxycillin group 4 weeks after treatment. There were no significant differences in the number of bacteria in antrum and corpus.
Conclusions: There was an inverse relationship between the growth of commensal microflora and H. pylori during treatment in both groups. H. pylori was detectable in saliva and dental plaque by PCR. The original H. pylori strain was present in all but one relapsing patient.     

Eradication of Helicobacter pylori heals atrophic corpus gastritis caused by long-term treatment with omeprazole

 Long-term treatment with proton pump inhibitors in patients with Helicobacter pylori gastritis can lead to atrophic changes in the corpus mucosa. What is still unclear, however, is whether this atrophy can regress in response to Helicobacter pylori eradication. We report on a male patient with Helicobacter pylori gastritis receiving long-term treatment (4 years) with omeprazole for gastro-oesophageal reflux disease, who developed autoaggressive gastritis with progressive atrophy, hypochlorhydria, hypergastrinaemia and nodular ECL-cell hyperplasia. To determine whether these changes might be induced to regress, Helicobacter pylori eradication therapy was administered. Ten months after Helicobacter pylori eradication autoaggressive lymphocytic infiltrates were no longer detectable, and the glands in the corpus mucosa had normalised despite continued treatment with omeprazole – a finding that was confirmed at two further follow-up surveys performed at 6-month intervals. This case report shows that atrophy of the corpus mucosa developing under long-term treatment with a proton pump inhibitor can be cured by eradicating Helicobacter pylori. Received: 21 April 1998 / Accepted: 10 August 1998     

Activity of omeprazole on Helicobacter pylori and relation to toxicity of strains.

AIMS--To see whether the activity of omeprazole on Helicobacter pylori is associated with toxicity of strains; to determine whether omeprazole inhibited vacuolisation of cells in culture induced by H pylori cytotoxin and by ureas, and if omeprazole prevented H pylori motility. METHODS--Minimal inhibitory concentrations (MICs) of omeprazole were determined for seven cytotoxic and five non-cytotoxic H pylori strains. Omeprazole at different concentrations was incubated with cytotoxic and non-cytotoxic extracts of H pylori, or with purified H pylori urease, and added to cells in culture. Inhibition of motility by omeprazole was tested in semi-solid medium. RESULTS--MIC90 of omeprazole was 40 micrograms/ml. MICs for cytotoxic and noncytotoxic organisms were similar. Omeprazole did not prevent vacuolisation induced by the cytotoxic extract, but at high concentrations it inhibited the formation of vacuoles induced by urease. Motility was not inhibited by the drug. CONCLUSIONS--H pylori cytotoxin is not the target of the antimicrobial activity of omeprazole. Should the drug reach clinically effective concentrations in vivo, it could potentially prevent the mucosal damage caused by the vacuolising activity of urease.     

Helicobacter pylori.

Helicobacter pylori is a gram-negative bacterium which causes chronic gastritis and plays important roles in peptic ulcer disease, gastric carcinoma, and gastric lymphoma. H. pylori has been found in the stomachs of humans in all parts of the world. In developing countries, 70 to 90% of the population carries H. pylori. In developed countries, the prevalence of infection is lower. There appears to be no substantial reservoir of H. pylori aside from the human stomach. Transmission can occur by iatrogenic, fecal-oral, and oral-oral routes. H. pylori is able to colonize and persist in a unique biological niche within the gastric lumen. All fresh isolates of H. pylori express significant urease activity, which appears essential to the survival and pathogenesis of the bacterium. A variety of tests to diagnose H. pylori infection are now available. Histological examination of gastric tissue, culture, rapid urease testing, DNA probes, and PCR analysis, when used to test gastric tissue, all require endoscopy. In contrast, breath tests, serology, gastric juice PCR, and urinary excretion of [15N]ammonia are noninvasive tests that do not require endoscopy. In this review, we highlight advances in the detection of the presence of the organism and methods of differentiating among types of H. pylori, and we provide a background for appropriate chemotherapy of the infection.     

Protection against experimental Helicobacter pylori infection after immunization with inactivated H. pylori whole-cell vaccines

The protective effect of therapeutic oral immunization with homologous and heterologous formalin-inactivated Helicobacter pylori cells given together with cholera toxin as an adjuvant was evaluated with C57BL/6 mice infected with H. pylori Sydney strain 1 (SS1). The bacteria used for immunization were strains that were either homologous or heterologous with regard to the O antigen (i.e., the Lewis antigen [Le antigen]) expressed by the lipopolysaccharide of the infecting H. pylori SS1 strain. We found that repeated oral immunization with inactivated H. pylori SS1 cells can significantly inhibit an existing infection (P < 0.001) and that the protection induced by such therapeutic immunization extends to protection against reinfection (P < 0.001). A similar level of protection was also achieved by immunization with another inactivated H. pylori strain having the same O antigen (Le antigen) as the infecting H. pylori SS1 strain. In contrast, immunization with inactivated strains expressing a heterologous O antigen, Le(x), provided less protection or no protection. Immunization with H. pylori lysate preparations, on the other hand, resulted in significant comparable protection whether the lysates were prepared from an Le(x) strain or an Le(y) strain. Postimmunization gastritis was seen in mice that were protected after vaccination but not in unimmunized or unprotected mice. In conclusion, therapeutic immunization with inactivated H. pylori whole-cell vaccines may provide strong protection both against experimental H. pylori infection and against later reinfection.     

Diagnosis and treatment of Helicobacter pylori infection

National Danish guidelines for the diagnosis and treatment of Helicobacter pylori (Hp) infection have been approved by the Danish Society for Gastroenterology. All patients with peptic ulcer disease, gastric cancer, and MALT lymphoma should be tested for Hp. We also recommend testing in first degree relatives to patients with gastric cancer, in NSAID-naive patients, who need long-term NSAID therapy, and in patients presenting with dyspepsia and no alarm symptoms. Non-endoscoped patients can be tested with a urea-breath test or a faecal antigen test. Endoscoped patients can be tested with a rapid urease test. Proton pump inhibitor therapy should be stopped at least 1 week prior to Hp testing. All infected patients should be offered Hp eradication therapy. First-line treatment is 7-day triple therapy with a proton pump inhibitor and clarithromycine in combination with metronidazole or amoxicilline. Quadruple therapy for 2 weeks with bismuthsubsalicylate, tetracycline, metronidazole and a proton pump inhibitor is recommended in case of treatment failure. Hp testing should be offered to all patients after eradication therapy but is mandatory in patients with ulcer disease, noninvasive gastric cancer or MALT lymphoma. Testing after eradication should not be done before 4 weeks after treatment has ended.     

Long-term colonization with single and multiple strains of Helicobacter pylori assessed by DNA fingerprinting.

The gastric pathogen Helicobacter pylori establishes long-term chronic infections that can lead to gastritis, peptic ulcers, and cancer. The species is so diverse that distinctly different strains are generally recovered from each patient. To better understand the dynamics of long-term carriage, we characterized H. pylori isolates from initial and follow-up biopsy specimens from a patient population at high risk of H. pylori infection and gastric cancer. Eighty-five isolates were obtained from 23 patients and were analyzed by genomic restriction enzyme analysis, arbitrarily primed PCR fingerprinting, (random amplified polymorphic DNA analysis), and/or restriction of specific PCR-amplified genes (restriction fragment length polymorphism analysis). A single strain was found in sequential biopsy specimens from 12 of 15 patients (80%) receiving sucralfate. In the remaining three patients treated with sucralfate, two strains were identified in two patients and three strains were identified in the third patient. In contrast, a single strain was found in sequential biopsy specimens from only three of eight patients (37%) receiving bismuth, metronidazole, and nitrofurantoin. Two strains were identified in five other patients receiving bismuth-antibiotic (63%). Immunoglobulin G antibodies to H. pylori were present in the sera of all patients. Thus, H. pylori colonization can persist for long periods (up to at least 4 years), despite high titers of immunoglobulin G antibodies in serum. Resistance to metronidazole was noted in some strains before and/or after treatment, but all strains remained susceptible to amoxicillin, tetracycline, and nitrofurantoin.(ABSTRACT TRUNCATED AT 250 WORDS)     

A highly specific and sensitive DNA probe derived from chromosomal DNA of Helicobacter pylori is useful for typing H. pylori isolates.

HindIII-digested DNA fragments derived from an EcoRI-digested 6.5-kb fragment of chromosomal DNA prepared from Helicobacter pylori ATCC 43629 (type strain) were cloned into the pUC19 vector. A 0.86-kb insert was identified as a potential chromosomal DNA probe. The specificity of the probe was evaluated by testing 166 non-H. pylori bacterial strains representing 38 genera and 91 species which included aerobic, anaerobic, and microaerophilic flora of the upper and lower gastrointestinal tracts. None of the 166 non-H. pylori strains hybridized with this probe (100% specificity), and the sensitivity of this probe was also 100% when H. pylori isolates from 72 patients with gastritis and with the homologous ATCC type strain were tested by dot blot hybridization. The capability of this probe for differentiating between strains of H. pylori was evaluated by Southern blot hybridization of HaeIII-digested chromosomal DNA from 68 clinical isolates and the homologous ATCC type strain of H. pylori. Fifty-one unique hybridization patterns were seen among the 69 strains tested, demonstrating considerable genotypic variation among H. pylori clinical isolates. We propose that this probe would be of significant value for conducting epidemiologic studies.     

Comparison of isolates of Helicobacter pylori and Helicobacter mustelae.

On the basis of analysis of protein profiles, isolates of Helicobacter pylori and Helicobacter mustelae were less than 40% similar. Cytotoxin produced by H. pylori was not detected in isolates of H. mustelae. Both bacterial species agglutinated human erythrocytes. These results substantiate a taxonomic difference between H. pylori and H. mustelae.     

Chronic urticaria and Helicobacter pylori.

BACKGROUND: Although the clinical manifestations of chronic urticaria (CU) are similar in most patients, a variety of factors should be taken into consideration. In general, the cause of CU cannot be determined in most patients, and it is considered idiopathic. In the past several years, relationships between some patients with CU and hepatitis C or autoimmune thyroid diseases have been established. Similarly, other factors may also be considered as possible causes to explain certain patients with CU. Previously, some patients with CU have had their disease attributed to Helicobacter pylori (HP), but the relationship was only clinical. OBJECTIVE: None of the patients previously described included an immunological study. Thus, we studied a patient with CU, who showed marked clinical improvement after eradication of HP, to demonstrate an IgE relationship with this skin disease. METHODS: First, blood analytical parameters, roentgenograms, fecal examination for parasites, and skin tests were performed to try to establish an etiology. In addition, endoscopy with gastric biopsy confirmed HP colonization, and eradication treatment was prescribed. To investigate an immunological relationship, other tests performed included the following: HP-specific IgG, histamine release induced by HP, HP-specific IgE, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis with immunoblotting. RESULTS: The blood analytical parameters, roentgenograms, fecal examination for parasites, and skin tests were all negative. In contrast, the tests for HP-specific IgG, histamine release induced by HP, and HP-specific IgE were all positive. In addition, the sulfate-polyacrylamide gel electrophoresis with immunoblotting showed specific IgE binding to an extract of HP. CONCLUSIONS: Our results may indicate an immunological IgE relationship between HP colonization and CU in this particular patient.     

Diversity of Helicobacter pylori among Chinese persons with H. pylori infection

To determine whether there is diversity among clinical isolates of Helicobacter pylori in Chinese patients with peptic ulcer disease, 40 strains of H. pylori were isolated from antral biopsy specimens obtained at the gastroenterology clinic of Xiangya Hospital from January 1996 to June 1998. Total protein profile by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and DNA diversity by polymerase chain reaction-random amplified polymorphic DNA (PCR-RAPD) fingerprinting were performed with these isolates. All the isolates from peptic ulcer disease were relatively homogeneous in protein profiles, but they showed a great DNA sequence diversity by PCR-RAPD fingerprinting. In Chinese patients H. pylori demonstrated an enormous diversity. The diversity among clinical isolates of H. pylori could be distinctly demonstrated and this observation will be helpful in the management of intrafamilial and recurrent H. pylori infection. PCR-RAPD fingerprinting is an efficient method of distinguishing between clinical isolates of H. pylori.