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PubMed2005

Helicobacter felis and Helicobacter bizzozeronii induce gastric parietal cell loss in Mongolian gerbils.

Non-pylori helicobacter infections are associated with gastritis, gastric ulcers and MALT lymphomas in man. Approximately 50% of these are caused by helicobacters commonly found in dogs and cats, including Helicobacter felis, Helicobacter bizzozeronii and H. salomonis. In contrast to Helicobacter pylori, the virulence mechanisms of these species are unknown. In this study the virulence of H. felis, H. bizzozeronii and H. salomonis was investigated in Mongolian gerbils. Female SPF gerbils were inoculated intragastrically with H. felis, H. bizzozeronii or H. salomonis and sacrificed 3 weeks later. Fundus and antrum samples were taken for bacterial detection by PCR. A longitudinal strip covering all stomach regions was taken for histology. Gastric colonization, inflammation, apoptosis, loss of parietal cells and cell proliferation were assessed. Controls and H. salomonis inoculated gerbils were negative in PCR. H. felis and H. bizzozeronii inoculated animals were positive. H. felis inoculated animals showed loss of parietal cells extending from the limiting ridge into the fundus. A high cell proliferation rate was noticed in the mucosal area devoid of parietal cells. A dense band of apoptotic cells and large numbers of Helicobacter bacteria were seen at the transition zone between affected and normal parietal cells. In H. bizzozeronii infected gerbils, this was less pronounced. Focal apoptotic loss of gastric epithelial cells was spatially associated with the presence of bacteria especially in H. felis and to a lesser extent in H. bizzozeronii infected gerbils. This loss of cells may lead to intestinal metaplasia.

Animals↗
PubMed2003

Potential for proteomic profiling of Helicobacter pylori and other Helicobacter spp. using a ProteinChip array.

The Helicobacter genus is associated with a wide spectrum of pathologies in the gastrointestinal tract. However, in contrast to Helicobacter pylori, few data are available regarding proteomic characteristics of enterohepatic helicobacters. Proteomic analysis of this genus has predominantly utilised two-dimensional gel electrophoresis methodology. In the present study we applied an innovative technique using ProteinChip arrays coupled with surface-enhanced laser desorption/ionisation time of flight mass spectroscopy to accurately assess the M(r) of proteins for comparative proteomic profiling. We analysed binding of outer membrane fractions to a weak cation exchange array for strains of H. pylori from culture collections and compared these profiles to fresh clinical isolates. In addition, we analysed profiles from Helicobacter pullorum, Helicobacter bilis and 'Helicobacter sp. flexispira'. The system proved rapid, accurate and reproducible. Distinct specific profiles for all the strains studied were identified. However, strains from culture collections that have undergone numerous subcultures had almost identical profiles. In contrast, profiles from fresh clinical isolates were markedly different. Moreover, certain features of the profiles from the enterohepatic species were conserved.

Animals↗
PubMed2003

Helicobacter pylori and extragastric diseases -- other helicobacters.

The role of Helicobacter pylori infection is explored in more and more extragastric diseases without definite proof in most of the studies, except possibly some hematologic diseases. In cardiovascular diseases, including stroke, the presence of CagA positive strains may be involved. The possible role of helicobacters in hepatobiliary diseases goes beyond that of H. pylori to involve enterohepatic helicobacters. New Helicobacter species are regularly described and molecular methods are developed to improve their detection. Helicobacter felis remains the major species to be used in animal models of Helicobacter infection.

Animals↗
PubMed2003

Isolated granulomatous gastritis successfully treated by Helicobacter pylori eradication: a possible association between granulomatous gastritis and Helicobacter pylori.

We report two cases of granulomatous gastritis that resolved completely with Helicobacter pylori eradication. Two Japanese women, one 61 years old and one 58 years old, presented to our hospital with epigastralgia. Endoscopy revealed multiple shallow ulcerative lesions in the gastric corpus of both patients. Biopsy specimens demonstrated acute and chronic inflammation with multiple small, noncaseating granulomas at the level of the foveolar isthmi-the junction between the pits and the glands. Both specimens were positive for Helicobacter pylori. No other causes of organic granulomatous disease could be found. Both patients were diagnosed as having isolated granulomatous gastritis and were given triple therapy for Helicobacter pylorieradication, with their fully informed consent. The granulomatous gastritis resolved after successful Helicobacter pylorieradication therapy. This report describes a possible association between isolated granulomatous gastritis and Helicobacter pyloriinfection. To our knowledge, this is the first report describing isolated granulomatous gastritis successfully treated by triple therapy ( Helicobacter pylorieradication therapy).

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1995

Comparison of Helicobacter mustelae and Helicobacter pylori adhesion to eukaryotic cells in vitro.

BACKGROUND & AIMS: Bacterial adhesion to mucosal surfaces is an important pathogenic mechanism for Helicobacter-induced gastritis. The aims of this study were to compare binding of selected Helicobacter mustelae and Helicobacter pylori strains to lipids extracted from HEp-2, Chinese hamster ovary, human embryonic lung cells, and ferret gastrointestinal tissues as well as to intact tissue culture cells and to analyze the fatty acids of the receptor. METHODS: Thin-layer chromatography overlay binding and a receptor-based immunoassay detected adhesion of bacteria to commercial lipids and to individual species within the lipid extracts. H. mustelae binding to tissue culture cells was performed by whole cell bacterial adhesion assay. RESULTS: H. mustelae and H. pylori both bound to phosphatidylethanolamine and lysophosphatidylethanolamine. Adhesion of H. mustelae to intact eukaryotic cells correlated with the amount of phosphatidylethanolamine. Binding of helicobacters was greater to lipids derived from ferret antrum compared with colon (P < 0.05). Biochemical analysis suggested that heterogeneity in fatty acid composition of phosphatidylethanolamine could influence the degree of Helicobacter binding. CONCLUSIONS: Adhesion of Helicobacter strains correlates with the quantity of phosphatidylethanolamine present in the epithelial cell and with the differences in the fatty acid profile of the lipid.

Animals↗
PubMed1999

An uncommon Helicobacter isolate from blood: evidence of a group of Helicobacter spp. pathogenic in AIDS patients.

An unusual Helicobacter sp. was isolated from the blood of a human immunodeficiency virus (HIV)-infected patient. This organism had spiral morphology, with single amphitrichous flagella, and was negative for hippurate hydrolysis, production of urease, and reduction of nitrate. 16S rRNA gene sequence analysis verified that the isolate was a species of Helicobacter, most closely related to an undescribed Helicobacter-like isolate from Vancouver, British Columbia, Canada, and to Helicobacter westmeadii, a recently described species from Australia. Both organisms had also been isolated from the blood of HIV-infected patients. These blood isolates, along with Helicobacter cinaedi, form a cluster of closely related Helicobacter spp. that may represent an emerging group of pathogens in immunocompromised patients.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Clinical onset of the Crohn's disease after eradication therapy of Helicobacter pylori infection. Does Helicobacter pylori infection interact with natural history of inflammatory bowel diseases?

BACKGROUND: There are conflicting reports concerning the prevalence of Helicobacter pylori infection in patients with inflammatory bowel diseases: some studies connected Sulphasalazine therapy and lower incidence of Helicobacter pylori infection, but others showed lower prevalence of Helicobacter pylori infection in inflammatory bowel diseases despite the choice of therapy. CASE REPORT: A 28-year-old male patient presented in January 1996 with the symptoms of ulcer like dyspepsia. There was no significant abnormality on physical examination, laboratory testing and abdominal ultrasound. Histology examination of the biopsy specimen taken during the upper endoscopy revealed Helicobacter pylori associated active gastritis only in the corporal part of the stomach. After two weeks eradication therapy (Omeprazole, Amoxicillin) he was well. Three months later, at the control endoscopy, granulomatous gastritis of the corporal localization was detected, without Helicobacter pylori present. Antral mucosa appeared normal, both, on endoscopy and histology examination. In July 1996 he started with cramping abdominal pain, mild periodical fever and episodes of watery diarrhea. In laboratory results we found nonspecific signs of inflammation. We repeated upper endoscopy, colonoscopy and enteroclysis--with evidence of segmental stenotic lesions of the upper part of ileum and jejunum. Again, we confirmed granulomatous gastritis and small granuloma in the proximal jejunum. After starting the 5-ASA therapy in combination with Metronidazol, patient was better clinical condition, and laboratory results were normal. We suggested mesalamine maintenance therapy 1 gr. every day, and three years later he is well, in clinical remission of Crohn's disease. CONCLUSION: The clinical course of the Crohn's disease maybe "sui generis" connected with Helicobacter pylori infection- but the exact mechanisms remain to be discovered.

Abdominal Pain↗
PubMed1996

Culture and characteristics of Helicobacter bizzozeronii, a new canine gastric Helicobacter sp.

Organisms whose cells were large, tight spirals were isolated from gastric biopsies of dogs. Touch cytology samples from all of the dogs contained large spiral organisms. Characteristics of 10 strains are described. These organisms were 5 to 10 microns long by 0.3 microns wide, and each cell had 10 to 20 sheathed flagella at both ends of the cell. The cells did not have periplasmic fibrils. These organisms were microaerophilic and grew at 37 and 42 degrees C but not at 25 degrees C on brain heart infusion agar containing blood. They did not grow on brucella blood agar. They were catalase and oxidase positive, hydrolyzed urea but not hippurate, reduced nitrate, and were resistant to nalidixic acid but susceptible to cephalothin and metronidazole. In contrast to Helicobacter felis, they hydrolyzed indoxyl acetate. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein profiles of all of the strains were similar, and the protein patterns of these organisms differed from those of other Helicobacter spp. Dot blot DNA-DNA hybridization experiments revealed that the new strains were closely related to each other but clearly different from H. felis, Helicobacter pylori, Helicobacter mustelae, and Campylobacter jejuni. The name Helicobacter bizzozeronii sp. nov. is proposed for these organisms. Our results suggest that other "uncultured" gastric helicobacters may be cultured if optimal culture conditions are found.

Animals↗
PubMed1997

Helicobacter rodentium sp. nov., a urease-negative Helicobacter species isolated from laboratory mice.

A spiral-shaped bacterium with bipolar, single, nonsheathed flagella was isolated from the intestines of laboratory mice. The organism grew at 37 and 42 degrees C under microaerobic and anaerobic conditions, did not hydrolyze urea, was weakly positive for catalase and oxidase, reduced nitrate to nitrite, did not hydrolyze indoxyl acetate or hippurate, and was resistant to cephalothin and nalidixic acid. This is the first urease-negative, murine Helicobacter spp. isolated from intestines. Also, Helicobacter pullorum and this bacterium are unique among the genus Helicobacter in having nonsheathed flagella. The new bacterium appears to be part of the normal intestinal flora; although its pathogenic potential is unknown, this organism was also isolated from scid mice with diarrhea that were co-infected with Helicobacter bilis. On the basis of 16S rRNA gene sequence analysis data and biochemical and phenotypic criteria, the new organism is classified as a novel helicobacter, for which we propose the name Helicobacter rodentium. The type strain is MIT 95-1707 (= ATCC 700285).

Animals↗
PubMed2000

Helicobacter aurati sp. nov., a urease-positive Helicobacter species cultured from gastrointestinal tissues of Syrian hamsters.

A novel helicobacter with the proposed name Helicobacter aurati (type strain MIT 97-5075c) has been isolated from the inflamed stomachs and ceca of adult Syrian hamsters. The new species is fusiform with multiple bipolar sheathed flagella and periplasmic fibers; it contains urease and gamma-glutamyl transpeptidase. By 16S rRNA sequencing and repetitive element PCR-based DNA fingerprinting, it was found that H. aurati represents a distinct taxon and clusters with Helicobacter muridarum, Helicobacter hepaticus, and Helicobacter sp. MIT 94-022. H. aurati was recovered from hamsters housed in various research and vendor facilities. Further studies are necessary to define its association with disease and other microbiota in hamsters, as well as its impact on research projects involving hamsters. H. aurati (GenBank accession number AF297868) can be used in animal experiments to define the factors that are important for gastric helicobacter pathogenesis.

Animals↗
PubMed2000

Helicobacter mesocricetorum sp. nov., A novel Helicobacter isolated from the feces of Syrian hamsters.

A spiral-shaped bacterium with bipolar, single, nonsheathed flagella was isolated from the feces of Syrian hamsters. The bacterium grew as a thin spreading film at 37 degrees C under microaerobic conditions, did not hydrolyze urea, was positive for catalase and alkaline phosphatase, reduced nitrate to nitrite, did not hydrolyze hippurate, and was sensitive to nalidixic acid but resistant to cephalothin. Sequence analysis of the 16S rRNA gene and biochemical and phenotypic criteria indicate that the novel bacterium is a helicobacter. The novel bacterium is most closely related to the recently described mouse enteric helicobacter, Helicobacter rodentium. This is the first urease-negative Helicobacter species with nonsheathed flagella isolated from feces of asymptomatic Syrian hamsters. We propose to name this novel helicobacter Helicobacter mesocricetorum. The type strain is MU 97-1514 (GenBank accession number AF072471).

Alkaline Phosphatase↗
PubMed2000

Misidentifying helicobacters: the Helicobacter cinaedi example.

Whole-cell protein electrophoresis and biochemical examination by means of a panel of 64 tests were used to identify 14 putative helicobacters to the species level. The results were confirmed by means of DNA-DNA hybridization experiments and were used to discuss misidentification of helicobacters based on 16S rRNA gene sequence data. The data indicated that comparison of near-complete 16S ribosomal DNA sequences does not always provide conclusive evidence for species level identification and may prove highly misleading. The data also indicated that "Helicobacter westmeadii" is a junior synonym of Helicobacter cinaedi and that Helicobacter sp. strain Mainz belongs to the same species. H. cinaedi occurs in various animal reservoirs, including hamsters, dogs, cats, rats, and foxes. Appropriate growth conditions and identification strategies will be required to establish the genuine significance of this widely distributed Helicobacter species.

Animals↗
PubMed1992

Results of a multicentre European survey in 1991 of metronidazole resistance in Helicobacter pylori. European Study Group on Antibiotic Susceptibility of Helicobacter pylori.

In 1991 a multicentre survey on the prevalence of metronidazole resistance in Helicobacter pylori in vitro was carried out in 12 hospitals in 11 different European countries. The susceptibility of Helicobacter pylori to metronidazole was determined in each centre by measuring the MIC on agar with the PDM E-test (AB Biodisk) according to a standard procedure. Overall, 122 of 443 (27.5%) strains tested were resistant to metronidazole (MIC > 8 micrograms/ml). The level of resistance to metronidazole varied markedly between centres (from 7% to 49%) and was found to be substantially higher in Africans and other non-Caucasian subjects than in natives from European countries. The overall rate of resistance to metronidazole was higher in females (34.7%) than in males (23.9%), and varied according to the age group, being highest among women aged 20 to 39 (50%). Previous use of metronidazole was reported in only 16 patients, 11 of whom (68.8%) harboured resistant Helicobacter pylori strains. Although differences in the rate of metronidazole resistance in Helicobacter pylori most probably relate to variations in use of this drug in different populations, such use may frequently go unrecognized. This study emphasises the importance of monitoring the drug resistance of Helicobacter pylori on a local basis. Standardisation of the methods for testing the susceptibility of Helicobacter pylori in vitro is clearly needed for this purpose.

Adult↗
PubMed2006

Incidence of Helicobacter felis and the effect of coinfection with Helicobacter pylori on the gastric mucosa in the African population.

Helicobacter pylori and Helicobacter felis are two of the Helicobacter spp. that infect humans. H. pylori has been linked to significant gastric pathology. Coinfection with Helicobacter spp. may influence infectious burden, pathogenesis, and antibiotic resistance; however, this has not been studied. The aims of this study were to identify the incidence of H. felis and to analyze the effects of coinfection with both organisms on gastric pathology in a well-characterized South African population. Biopsy samples from the gastric corpora and antra of volunteers (n = 90) were subjected to histological examination and PCR for the identification of H. pylori and H. felis. We further investigated the effect of global strain type on the occurrence of precursor lesions by assigning nucleotide sequences derived from PCR amplification of three genes to global groupings (ancestral Africa1, ancestral Africa2, ancestral Europe, ancestral Asia, and mixed). H. pylori was detected in 75 (83.3%), H. felis in 23 (25.6%), and coinfection in 21 (23.3%) of the volunteers by PCR. H. felis was randomly distributed among adults and children but clustered within families, suggesting intrafamilial transmission. Analysis of histopathology scores revealed no differences in atrophy, activity, and helicobacter density between H. felis-positive and H. felis-negative volunteers. H. pylori substrains common to southern Africa showed no differences in inflammation or atrophy scores. The incidences of H. felis and coinfection with H. pylori in the African population are high. H. felis infection, however, does not influence specific gastric pathology in this population.

Adolescent↗
PubMed1995

Oral immunization with Helicobacter pylori urease B subunit as a treatment against Helicobacter infection in mice.

BACKGROUND & AIMS: Eradication of Helicobacter pylori infections in humans results in the healing of gastritis and gastric ulcers. This study used a mouse model to test whether oral vaccination can cure Helicobacter infection and gastritis. METHODS: Mice were infected with Helicobacter felis. Three weeks after infection, the mice were orally immunized with H. pylori urease B subunit. Control mice were simultaneously infected but sham immunized. RESULTS: Three to 8 weeks after oral immunization of H. felis-infected mice with recombinant H. pylori urease B subunit, the infection cleared and there was no evidence of gastritis. Vaccinated mice remained protected against two consecutive H. felis challenges. CONCLUSIONS: These results show that the lack of natural immunity against Helicobacter can be overcome by oral immunization and that vaccination offers a novel therapeutic approach to Helicobacter-induced gastritis.

Administration, Oral↗
PubMed2000

Discrepancy between Helicobacter pylori stool antigen assay and urea breath test in the detection of Helicobacter pylori infection.

BACKGROUND: The reference diagnostic methods available for detection of Helicobacter pylori infection are either invasive (histology) or expensive and highly sophisticated (Urea Breath Test). A new enzyme immunoassay, which can be easily performed in any laboratory, has been developed to detect Helicobacter pylori in stool specimens (HpSA-Meridian Diagnostics, Cincinnati, USA). Aim of the study was to compare HpSA to Urea Breath Test. PATIENTS AND METHODS: A total of 125 patients (52 never treated for Helicobacter pylori infection and 73 after Helicobacter pylori eradication therapy) referring to our Department, underwent both tests within two weeks. RESULTS: Contrasting results between the two tests were found in 30% of cases: in 19% of the untreated patients and in 37% of the treated patients (p<0.001). The main discrepancy consisted in positive HpSA associated with negative Urea Breath Test. Mean HpSA value in such conditions was 0.273 optical density, while in patients with both positive tests, it was 1.192 optical density. In untreated, but not in treated patients, raising the HpSA cut off value significantly decreased the percentage of conflicting results. CONCLUSIONS: Some disagreement was detected between HpSA and Urea Breath Test results, especially in treated patients. Possible explanations for our findings are a low HpSA cut off value together with the identification of Helicobacter pylori coccoid forms by the immunoassay but not by the urease based Urea Breath Test. The higher percentage of discrepancy detected in treated patients might support this hypothesis.

Adolescent↗
PubMed2001

Ranitidine bismuth citrate or omeprazole-based triple therapy for Helicobacter pylori eradication in Helicobacter pylori-infected non-ulcer dyspepsia.

AIM: To test the eradication rate of Helicobacter pylori by ranitidine bismuth citrate-based triple therapy, and evaluate the symptomatic response of Helicobacter pylori eradication therapy for non-ulcer dyspepsia. METHODS: A total of 59 consecutive Helicobacter pylori infected non-ulcer dyspepsia patients were randomly selected to receive either one of two triple therapy regimens, including metronidazole, amoxycillin plus ranitidine bismuth citrate (RAM group) or omeprazole (OAM group). To determine the success of eradication, patients underwent the 13C-urea breath test, 6 weeks and one year after treatment. The dyspeptic symptom scores were also assessed at the time of enrolment, 6 weeks and one year after treatment. RESULTS: Per-protocol and intention-to-treat eradication rates were 77.7% and 70% in RAM group and 83.8% and 68.9% in OAM group (p = non significant). At both the 6th week and at the first year after treatment, the mean symptom scores were lower than pre-treatment scores in the study population, regardless of whether treatment was successful or not. However, patients, whether eradicated successfully or not-eradicated, presented similar 6-week and 1-year scores. CONCLUSIONS: One-week RAM triple therapy, which is cheaper than the OAM regimen, is a relatively effective alternative regimen for Helicobacter pylori eradication in Taiwanese. Triple therapy for Helicobacter pylori eradication was not the whole management for the relief of dyspeptic symptoms of non-ulcer dyspepsia patients.

Adult↗
PubMed2001

The 26-kilodalton, AhpC homologue, of Helicobacter pylori is also produced by other Helicobacter species.

BACKGROUND: The 26 kDa protein, which is an alkyl hydroperoxide reductase (AhpC) homologue, has earlier been described as specific for Helicobacter pylori. The aims of this study were to analyse whether this protein, or the corresponding gene, could be identified in other Helicobacter species. MATERIALS AND METHODS: Two different monoclonal antibodies (Mabs), which recognise the 26 kDa protein in H. pylori, were used in immunoblots to determine the presence of the protein in 10 Helicobacter species. PCR was performed in order to analyse whether the gene was detectable and the PCR products were sequenced. Southern and Northern blot analyses were done on chromosomal DNA and total RNA, respectively, isolated from some selected Helicobacter species in order to compare the genes and mRNA transcripts to H. pylori. RESULTS: The 26 kDa protein was identified in H. nemestrinae (primate), H. acinonychis (cheetah), H. bilis (mouse), H. felis (cat) and H. salomonis (dog) but not in H. mustelae (ferret), H. cinaedi (human), H. canis (dog), H. fennelliae (human) or H. pullorum (poultry). By PCR the gene was also recognised in H. mustelae, H. cinaedi and H. pullorum. The PCR products showed high sequence homology (66-98%) compared to H. pylori. The gene was also highly conserved in four H. pylori strains (94-99% homology). Southern blot showed that the H. nemestrinae and H. acinonychis chromosomal DNA contained a single copy of the gene and the Northern blot analyses indicated mono-cistronic transcription of the gene in these two species, as has been found in H. pylori. CONCLUSIONS: A gene similar to ahpC was found in eight out of 10 Helicobacter species analysed.

Animals↗