Publications

TitleAbstractYear
Filter
PMID
Filter
haemagglutination profiles of helicobacter species that cause gastritis in man and animals.thirty-five helicobacter pylori isolates, 21 h. mustelae isolates and four strains of h. felis were compared for their ability to agglutinate red blood cells (rbcs). isolates were examined in a slide haemagglutination assay with rbcs from 11 animal species, including rodents, carnivores and primates, as well as man. rbcs were agglutinated by 65-90% of h. mustelae isolates and 16-57% of h. pylori isolates. treatment of h. mustelae with pronase and heat inhibited haemagglutination (ha) whereas hea ...19921279175
helicobacter mustelae isolation from feces of ferrets: evidence to support fecal-oral transmission of a gastric helicobacter.helicobacter mustelae has been isolated from stomachs of ferrets with chronic gastritis and ulcers. when h. mustelae is inoculated orally into h. mustelae-negative ferrets, the animals become colonized and develop gastritis, a significant immune response, and a transient hypochlorhydria. all of these features mimic helicobacter pylori-induced gastric disease in humans. because the epidemiology of h. pylori infection is poorly understood and its route of transmission is unknown, the feces of wean ...19921370432
use of dna restriction endonuclease digest and ribosomal rna gene probe patterns to fingerprint helicobacter pylori and helicobacter mustelae isolated from human and animal hosts.variation amongst strains of helicobacter pylori and helicobacter mustelae was examined by dna restriction endonuclease digestion and rrna gene patterns generated using a non-radioactive probe. chromosomal dna was extracted from 30 cultures of h. pylori from human, rhesus monkey and pig gastric mucosa, and from three h. mustelae isolates from ferret gastric mucosa. dna fingerprinting with hae iii and hind iii showed h. mustelae was relatively homogeneous but revealed genomic heterogeneity within ...19901698260
characterisation of the urease from helicobacter pylori and comparison with the ureases from related spiral gastric bacteria.the urease enzyme of helicobacter pylori was partially purified from whole cell extracts and found to have a molecular weight of 484 +/- 12 kda. ten monoclonal antibodies (mabs) were produced against four different epitopes of the native enzyme. these mabs also recognised the ureases of h. pylori-like organisms isolated from monkeys and pigs and the h. mustelae urease from ferrets. the urease enzymes of each of these organisms were found to be of the same molecular weight. the urease enzyme of h ...19911711875
spiral organisms: what are they? a microbiologic introduction to helicobacter pylori.the stomach provides a hostile environment to most microorganisms owing to the antibacterial effect of gastric acidity. however, over the period of mammalian evolution a highly specialized group of bacteria has evolved to inhabit the gastric mucosa. the common features of these bacteria that allow survival in the stomach and colonization of their natural ecologic niche, mucus, are a specialized form of motility, microaerophilism, and very high activity of the enzyme urease. other important adapt ...19911775930
gastric colonization of the ferret with helicobacter species: natural and experimental infections.helicobacter mustelae, isolated from the stomachs of adult ferrets, appears to have a world-wide distribution. ferrets are colonized with h. mustelae at a young age, usually 5-6 weeks; in our experience 100% of adult ferrets are colonized in both the antrum and the fundus. gastric infection correlates with elevation of serum igg antibodies to h. mustelae. in the oxyntic mucosa the presence of superficial gastritis coincides closely with the presence of h. mustelae. in the distal antrum the organ ...19911833810
purification and characterization of helicobacter mustelae urease.helicobacter mustelae is a urease-rich bacterium associated with gastritis in ferrets. the ureases of h. mustelae and helicobacter pylori, a bacterium implicated in human gastritis, share many characteristics. helicobacter sp. ureases appear to be unique among bacterial enzymes in exhibiting submillimolar km values and in being composed of two subunits.19911879950
characterization of strains of helicobacter pylori: one-dimensional sds-page as a molecular epidemiologic tool.one-dimensional linear sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total proteins, coupled with a computerized numerical analysis, was used to distinguish among strains of helicobacter pylori. one hundred seventy-five clinical strains and five reference strains of h. pylori from humans, four isolates of helicobacter mustelae from ferrets, and three isolates of h. pylori-like organisms (hplos) from miniature swine were examined. intraspecies and interspecies comparisons were made ...19911925314
oral immunization against helicobacter pylori.helicobacter pylori, which has been associated with gastritis and duodenal ulcers, commonly chronically infects adults. eradication of this microorganism, which is difficult to achieve, results in normalization of gastritis and marked reduction in the relapse rate of duodenal ulcers. since eradication is difficult to achieve, prevention of initial colonization of the gastrointestinal tract may be a viable alternative for abrogation of h. pylori-associated gastroduodenal disease. to test the feas ...19912050403
helicobacter mustelae-associated gastritis in ferrets. an animal model of helicobacter pylori gastritis in humans.gastric helicobacter mustelae was present in 100% of 11 adult female ferrets (mustela putorius furo). the high immunoglobulin g antibody levels to h. mustelae in all ferrets showed a significant immune response to the organism. urease mapping of the ferret stomach indicated that the bacteria heavily colonized the proximal duodenum and antrum and, to a lesser extent, the corpus. the histological gastritis observed coincided with presence of h. mustelae. superficial gastritis was noted in the oxyn ...19902365188
helicobacter pylori-like microorganisms and chronic active gastritis in ferrets.to determine the prevalence and histology of helicobacter pylori (hp) associated gastritis in young ferrets, we examined 36 normal 2- to 4-month old ferrets. identification of hp-like microorganisms included warthin starry stains of tissue sections, rapid urease test on fresh tissue, and culture. hp-like microorganisms were found in the stomachs of 35/36 ferrets. the highest density of microorganisms was seen in the antrum, where hp-like microorganisms were present in the pits and in deep glands ...19902371981
eradication of helicobacter mustelae from the ferret stomach: an animal model of helicobacter (campylobacter) pylori chemotherapy.colonization of the ferret stomach by helicobacter mustelae has been suggested as a possible animal model for helicobacter pylori-associated gastroduodenal disease of humans. our study was designed to determine whether antimicrobial chemotherapy could eradicate h. mustelae from ferrets. triple antimicrobial therapy combining amoxicillin, metronidazole, and bismuth subsalicylate was successful in eradicating the organism from 5 of 7 (71%) adult ferrets. despite apparent in vitro susceptibility, n ...19902393285
microbiological aspects of helicobacter pylori (campylobacter pylori).the human gastric pathogen campylobacter pylori has recently been reclassified as helicobacter pylori, and a related spiral bacterium found in the stomach of ferrets has been designated helicobacter mustelae. the general microbiological features of helicobacter pylori are delineated here, with details of phenotypic differences between helicobacter pylori and helicobacter mustelae; comparisons are made with wolinella succinogenes and campylobacter jejuni. the helicobacter organisms possess an ext ...19902406141
proteolytic activities of human campylobacter pylori and ferret gastric campylobacter-like organism.the levels of proteolytic activity in cell washes, lysates and pellets of c. pylori and gastric campylobacter-like organisms isolated from humans and ferrets, respectively, have been studied using porcine mucus glycoprotein and bovine haemoglobin substrates. the total haemoglobin degrading activity, expressed by 10(12)-10(13) cfu of either organism, was no greater than 3 micrograms chymotrypsin equivalents. the mucolytic specific activity (rate of mucus peptide bond hydrolysis by bacterial prote ...19892673233
cellular fatty acid composition of campylobacter pylori from primates and ferrets compared with those of other campylobacters.the cellular fatty acid profiles of newly described campylobacters were determined on a polar, capillary column. six isolates of the gastric spiral organism, campylobacter pylori subsp. mustelae, from ferrets from australia, england, and the united states were all found to have a similar fatty acid profile which was different from that of c. pylori from humans; c. pylori subsp. mustelae did not have 3-hydroxyoctadecanoic acid (3-oh c18:0) and had much less tetradecanoic acid (c14:0) and much mor ...19892745703
gastric colonization by campylobacter pylori subsp. mustelae in ferrets.campylobacter pylori subsp. mustelae was cultured from both normal and inflamed gastric mucosa of ferrets. examination of neonatal, juvenile, and adult ferrets established that the gastric mucosa in the majority of preweanling (age, less than 6 weeks) ferrets sampled were not colonized with c. pylori subsp. mustelae, whereas the gastric mucosa of 100% of adult ferrets were colonized with this gastric organism. c. pylori subsp. mustelae was isolated from the gastric mucosa on a sequential basis f ...19883169994
the characterization and pathological significance of gastric campylobacter-like organisms in the ferret: a model for chronic gastritis?gastric campylobacter-like organisms (clo) were isolated from gastric tissues removed at sacrifice from 17 mature ferrets; all animals were colonized, but no macroscopic mucosal lesions or histological features of chronic gastritis were seen. the isolates resembled campylobacter pylori in many cultural and biochemical characteristics, and produced substantial urease activity, but there were sufficient differences from c. pylori to suggest that ferret gastric clo represents a separate species. co ...19883181311
isoelectric focusing of ureases from campylobacter pylori and related organisms.agarose gel isoelectric focusing was used to determine the isoelectric points of ureases from strains of gastric campylobacterlike organisms isolated from ferrets (pi 5.4), baboons (pi 5.7), and pigs (pi 5.9) and from isolates of campylobacter pylori in humans (pi 5.9). this technique may help differentiate these closely related bacteria.19883230144
comparative sensitivities to antimicrobial agents of campylobacter pylori and the gastric campylobacter like organism from the ferret. 19873680554
rabbit and ferret parietal cell inhibition by helicobacter species.we tested sonicates of helicobacter pylori, h. mustelae, and h. felis for inhibition of acid secretion in rabbit and ferret isolated gastric glands. three h. pylori strains, two of three h. mustelae strains, and two h. felis strains significantly inhibited acid secretion in rabbit cells by 95.2-93.3%, 55.9% and 96.4%, and 83.4-96%, respectively. all helicobacter strains examined inhibited acid secretion by ferret cells by 65.3-76.8%, 89.1-97.6%, and 85.8-92.8%. h. pylori inhibited acid secretion ...19957529671
effect of helicobacter mustelae infection on ferret gastric epithelial cell proliferation.the effect of helicobacter mustelae infection on gastric epithelial proliferation was studied in ferrets colonized with h.mustelae and specific pathogen-free (spf) ferrets not infected with h.mustelae. thirteen h. mustelae-infected ferrets between the ages of 13 and 32 months and 16 spf ferrets between 6 and 18 months were analyzed. bacterial cultures, urease tests and warthin-starry stains were used to identify h.mustelae. tissues obtained from the antrum and the body regions of the stomach wer ...19957634423
comparison of helicobacter mustelae and helicobacter pylori adhesion to eukaryotic cells in vitro.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.19957657097
comparative ultrastructural and functional studies of helicobacter pylori and helicobacter mustelae flagellin mutants: both flagellin subunits, flaa and flab, are necessary for full motility in helicobacter species.helicobacter mustelae causes chronic gastritis and ulcer disease in ferrets. it is therefore considered an important animal model of human helicobacter pylori infection. high motility even in a viscous environment is one of the common virulence determinants of helicobacter species. their sheathed flagella contain a complex filament that is composed of two distinctly different flagellin subunits, flaa and flab, that are coexpressed in different amounts. here, we report the cloning and sequence de ...19957768796
protein hpn: cloning and characterization of a histidine-rich metal-binding polypeptide in helicobacter pylori and helicobacter mustelae.helicobacter pylori is a human gastrointestinal pathogen involved in gastritis, duodenal ulcers, and gastric neoplasia. this microorganism produces large amounts of a urease which, like all known ureases, has nickel in the active site. we have identified a protein in clinical isolates of h. pylori and an identical protein in the ferret pathogen helicobacter mustelae that strongly binds ni2+ and zn2+. this protein has been named hpn to emphasize its origins in h. pylori and its affinity for nicke ...19957790085
helicobacter pylori and the pathogenesis of duodenal ulcer.in summary, it appears that the role of h. pylori in duodenal ulcerogenesis is not directly associated with acid hypersecretion. similarly, it seems unlikely that h. pylori-induced autoimmune injury is an important mechanism in duodenal ulcerogenesis. an essential question remaining is whether h. pylori infection of areas of gastric metaplasia in the duodenum is essential to ulcer pathogenesis. the low yield of h. pylori in duodenal biopsy studies argues against this mechanism. it is possible th ...19947964119
identification and molecular characterization of a major ring-forming surface protein from the gastric pathogen helicobacter mustelae.the spiral microaerophilic bacterium helicobacter mustelae is linked to gastritis and gastric ulcers in ferrets. electron microscopy of h. mustelae showed the presence of a laterally extensive array of 8.5-nm-diameter rings on the cell surface, which was shown to be composed of a 150kda protein. this protein was purified, and the sequence of 10 amino-terminal residues was determined. polyclonal antibody against the purified 150 kda protein labelled the ring structures on the homologous strain by ...19948170397
gastric anti-secretory, mucosal protective, anti-pepsin and anti-helicobacter properties of ranitidine bismuth citrate.ranitidine bismuth citrate is a novel compound formed from ranitidine and a bismuth citrate complex. in conscious dogs, ranitidine bismuth citrate had similar activity to ranitidine hydrochloride as an inhibitor of histamine-induced gastric acid secretion when oral doses containing equivalent amounts of ranitidine base (0.1 or 0.3 mg/kg) were compared. in the rat, ranitidine bismuth citrate (3-30 mg/kg p.o.) prevented gastric mucosal damage induced by ethanol (fundic damage) and indomethacin (an ...19938364129
role of gastric ph in isolation of helicobacter mustelae from the feces of ferrets.helicobacter mustelae colonizes the gastric mucosa of ferrets and causes persistent chronic gastritis.19938380398
mnng-induced gastric carcinoma in ferrets infected with helicobacter mustelae.n-methyl-n-nitro-n'-nitrosoguanidine (mnng) is a gastric carcinogen in several animal species and has been used in a number of systems to dissect the co-carcinogenic potential of various compounds in the induction of gastric adenocarcinoma. recent epidemiological evidence suggests that helicobacter pylori may play a role as a co-carcinogen in the etiology of this tumor in humans and we have been interested in developing an animal model to study this possibility. a related organism, h. mustelae, ...19938403224
gastric bacteria other than helicobacter pylori.since the culture of helicobacter pylori from the human stomach in 1983 there has been renewed interest in other bacteria that had been observed in animal stomachs as early as late in the nineteenth century. many of these bacteria have now been isolated and have been shown to belong to the same genus, helicobacter, which currently contains nine species. study of the gastric helicobacters is important because it provides relevant information about how bacteria can survive in the gastric environme ...19938449568
helicobacter mustelae and helicobacter pylori bind to common lipid receptors in vitro.helicobacter pylori is a recently recognized human pathogen causing chronic-active gastritis in association with duodenal ulcers and gastric cancer. helicobacter mustelae is a closely related bacterium with similar biochemical and morphologic characteristics. h. mustelae infection of antral and fundic mucosa in adult ferrets causes chronic gastritis. an essential virulence property of both helicobacter species is bacterial adhesion to mucosal surfaces. the aim of this study was to determine whet ...19938500901
cloning and genetic characterization of the helicobacter pylori and helicobacter mustelae flab flagellin genes and construction of h. pylori flaa- and flab-negative mutants by electroporation-mediated allelic exchange.helicobacter pylori is one of the most common human pathogens. it causes chronic gastritis and is involved in the pathogenesis of gastroduodenal ulcer disease and possibly gastric carcinoma. helicobacter mustelae is a bacterium closely related to h. pylori that causes gastritis and ulcer disease in ferrets and is therefore considered an important animal model of gastric helicobacter infections. motility, even in a viscous environment, is conferred to the bacteria by several sheathed flagella and ...19938501031
helicobacter infections in laboratory animals: a model for gastric neoplasias?evidence is rapidly accumulating that helicobacter pylori is a major risk factor for human gastric adenocarcinomas and all low-grade b-cell gastric lymphomas. given this, there is a need to develop animal models with a view to discovering not only how carcinogenesis is initiated, but also how the process can be prevented. the lack of h. pylori animal models suitable for long-term studies means that alternatives are needed. the most productive models are likely to be the helicobacter mustelae-inf ...19958541035
animal models and vaccine development.following the demonstration of helicobacter pylori as a major gastroduodenal pathogen there was a need to develop animal models in order to investigate mechanisms of pathogenesis and to be able to test new treatment strategies. helicobacter pylori will only colonize a limited number of hosts including non-human primates, germ-free or barrier raised piglets, germ-free dogs and recently laboratory raised cats. although these models have proved useful there is a need for more convenient small anima ...19958563056
surface properties of helicobacter mustelae and ferret gastrointestinal mucosa.helicobacter mustelae is a gastric pathogen in ferrets that adheres to epithelial cells both in vitro and in vivo. in this study, the authors examine the role of surface hydrophobic properties in the adhesion of these organisms to eukaryotic cell surfaces. the surface properties of six h. mustelae strains were characterized by hydrophobic interaction chromatography (hic), salt aggregation testing (sat) and contact-angle measurement by axisymmetric drop-shape analysis (adsa). contact angles in mu ...19968697675
adherence of helicobacter pylori.helicobacter pylori infects only gastric type epithelium, to which it adheres closely and forms attaching-effacing lesions. similar lesions are also seen in ferrets infected with helicobacter mustelae, the only other host in which peptic ulcer occurs during the course of infection. these observations imply a specific interaction between bacterial adhesin(s) and host receptor(s). they account for the adherence of h. pylori to the gastric epithelium and suggest that adherence is an important virul ...19968730255
pcr detection of colonization by helicobacter pylori in conventional, euthymic mice based on the 16s ribosomal gene sequence.many animal models of helicobacter infection have been described, including infection in rhesus monkeys, ferrets, gnotobiotic piglets, and mice. these animal models utilize a combination of detection methods, including culture, urease testing, and histopathology, all of which may be unreliable, insensitive, or labor-intensive. development of new animal models of helicobacter pylori requires new methods of detection with increased sensitivity and specificity. we have developed sensitive and speci ...19968770506
therapeutic immunization against helicobacter mustelae in naturally infected ferrets.helicobacter infection of the gastric antrum is responsible for a number of gastric disorders. antibiotic therapy is lengthy and is not always effective. it has been shown previously that oral immunization against helicobacter felis in mice can prevent colonization after challenge. the aim of this study was to investigate the efficacy of therapeutic immunization in eradicating an established helicobacter infection and in reducing gastritis.19968964402
infection of the ferret stomach by isogenic flagellar mutant strains of helicobacter mustelae.helicobacter mustelae, like helicobacter pylori, possesses two flagellin proteins, flaa and flab. isogenic mutant strains of h. mustelae have been constructed by disruption of the flaa or flab gene with a kanamycin resistance cassette or by introduction of both a kanamycin and a chloramphenicol resistance gene to produce a double mutant. to determine whether one or both flagellin proteins are necessary for colonization and persistence of infection with h. mustelae, 19 ferrets, specific pathogen ...19979125590
helicobacter mustelae-associated gastric adenocarcinoma in ferrets (mustela putorius furo).helicobacter pylori in humans is associated with active, chronic gastritis, peptic ulcer disease, and most recently has been linked epidemiologically to gastric adenocarcinoma. a related organism, helicobacter mustelae, naturally infects ferrets and also causes a persistent gastritis, a precancerous lesion, and focal glandular atrophy of the proximal antrum. in this report, we document the clinical presentation and histopathologic confirmation of h. mustelae-associated gastric adenocarcinoma in ...19979163879
helicobacter mustelae-associated gastric malt lymphoma in ferrets.gastric lymphoma resembling gastric mucosa-associated lymphoid tissue (malt) lymphoma linked with helicobacter pylori infection in humans was observed in ferrets infected with h. mustelae. four ferrets with ante- or postmortem evidence of primary gastric lymphoma were described. lymphoma was diagnosed in the wall of the lesser curvature of the pyloric antrum, corresponding to the predominant focus of h. mustelae induced gastritis in ferrets. two ferrets had low-grade small-cell lymphoma and two ...19979212752
the expanding genus of helicobacter: pathogenic and zoonotic potential.the microbial flora of stomachs of humans and animals have been the focus of considerable research since the discovery that helicobacter pylori in humans caused a variety of gastric diseases. other helicobacter species have now been isolated from the stomachs of various mammals, including dogs, cats, ferrets, pigs, monkeys, and cheetahs, all of which are associated with various degrees of gastritis in their hosts. helicobacter species have also been isolated from the intestinal tracts of humans, ...19979232726
the role of helicobacter species in newly recognized gastrointestinal tract diseases of animals.because helicobacter pylori is now known to be a significant human pathogen, experimental animal models are increasingly being used to study the pathogenesis of this organism. unfortunately, early studies failed to establish h. pylori in animal models, and surprisingly, koch's postulates were initially fulfilled in two human volunteers. germfree experiments performed in pigs and pups however established that h. pylori would colonize in these animals, and gastritis was induced. certain macaque sp ...19979241625
what other regimens are under investigation to treat helicobacter pylori infection?the most common infection in the world, helicobacter pylori infection, is very specific, and present experience in treating infectious diseases is not applicable in general for this infection. animal models (e.g., mouse and ferret) are thus far inadequate as reliable screening models. old-fashioned trial-and-error treatment of infected humans is still the screening model and the gold standard in the evaluation of regimens aimed at eradication of h. pylori. a variety of studies on treatment of h. ...19979394775
natural and experimental helicobacter mustelae reinfection following successful antimicrobial eradication in ferrets.recrudescence or reinfection may occur after eradication of helicobacter pylori in humans.19969398911
characterization and therapy for experimental infection by helicobacter mustelae in ferrets.numerous clinical trials evaluating the efficacy of various antimicrobial compounds against helicobacter pylori infection have been performed in humans. a convenient animal model for helicobacter infection would facilitate the evaluation of novel therapies. these experiments were performed to evaluate the use of ferrets as a model of helicobacter infection.19969398912
effect of potent urease inhibitor, fluorofamide, on helicobacter sp. in vivo and in vitro.the therapeutic potential of urease inhibition of helicobacter pylori has been studied by examining the effect of the potent urease inhibitor, fluorofamide (n-(diaminophosphinyl)-4-fluorobenzenamide), on urease activity and bacterial survival in vivo and in vitro. in culture, acid protection in h. pylori was shown to be due to changes in the ph of the medium brought about by the release of ammonia. both the acid protection and the ammonia release were completely blocked by fluorofamide at low do ...19989508511
molecular mimicry of ferret gastric epithelial blood group antigen a by helicobacter mustelae.molecular mimicry of lewis blood group antigens by helicobacter pylori may be involved in immune evasion by the bacteria and in the pathogenesis of chronic atrophic gastritis. helicobacter mustelae infects ferrets naturally, causing gastritis, and may be involved in ulcerogenesis. the aim of this study was to determine if h. mustelae shows a similar form of molecular mimicry.19989516389
inhibition of helicobacter pylori and helicobacter mustelae binding to lipid receptors by bovine colostrum.helicobacter pylori, the etiologic agent of chronic-active gastritis and duodenal ulcers in humans, and helicobacter mustelae, a gastric pathogen in ferrets, bind to phosphatidylethanolamine (pe), a constituent of host gastric mucosal cells, and to gangliotetraosylceramide (gg4) and gangliotriaosylceramide (gg3). the effect of a bovine colostrum concentrate (bcc) on the interaction of h. pylori and h. mustelae to their lipid receptors was examined. bcc blocked attachment of both species to gg4, ...19989534968
animal models for host-pathogen interaction studies.there is no model of helicobacter pylori infection that exactly mimics the human diseases. in a particular, there are no good models of ulceration or gastric adenocarcinoma. patterns of gastritis induced in the animals tend to be lymphocytic and lack the neutrophil infiltration typical of h. pylori infection in the adult. however, the animal models are starting to provide valuable information with respect to factors involved in the colonisation of the gastric mucosa and the importance of host fa ...19989604440
animal models for gastric helicobacter immunology and vaccine studies.over the last decade animal models have been used extensively to investigate disease processes and therapy for helicobacter pylori infections. the h. pylori animal models which have been used in pathogenesis and vaccine studies include the gnotobiotic pig, non-human primates, cats, dogs, and several species of rodents including mice, rats, gerbils and guinea pigs. h. felis infection of mice and h. mustelae infection of ferrets have also been used. recently, investigators have begun using transge ...199910378428
animal models of gastroduodenal ulcer disease.animal models have played a significant role in research that aims to understand peptic ulceration. firstly, they have helped define basic mechanisms of gastric mucosal defence and repair. the basis for gastric injury following nsaid administration was facilitated by animal models that correlated well with disease in humans. in early studies, ulceration was induced by grossly damaging insults to the gastric mucosa that were unphysiological. with refinement these models provided a clearer appreci ...200010749090
adherence of isogenic flagellum-negative mutants of helicobacter pylori and helicobacter mustelae to human and ferret gastric epithelial cells.isogenic flagellum-negative mutants of helicobacter pylori and helicobacter mustelae were screened for their ability to adhere to primary human and ferret gastric epithelial cells, respectively. we also evaluated the adherence of an h. pylori strain with a mutation in the flba gene, a homologue of the flbf/lcrd family of genes known to be involved in the regulation of h. pylori flagellar biosynthesis. h. pylori and h. mustelae mutants deficient in production of flaa or flab and mutants deficient ...200010858255
involvement of a plasmid in virulence of campylobacter jejuni 81-176.campylobacter jejuni strain 81-176 contains two, previously undescribed plasmids, each of which is approximately 35 kb in size. although one of the plasmids, termed ptet, carries a teto gene, conjugative transfer of tetracycline resistance to another strain of c. jejuni could not be demonstrated. partial sequence analysis of the second plasmid, pvir, revealed the presence of four open reading frames which encode proteins with significant sequence similarity to helicobacter pylori proteins, inclu ...200010899834
review article: helicobacter pylori vaccines-the current status.in this review, we take a look at the current status in the development of a vaccine against the human pathogenic bacterium, helicobacter pylori, a major aetiological factor in peptic ulcer disease and gastric adenocarcinoma. various animal models are now in use from mice infected with h. pylori, through gnotobiotic pigs and primates to ferrets naturally infected with their own helicobacter, h. mustelae. a significant problem remains the requirement for a suitable mucosal adjuvant. detoxificatio ...200010971226
antigastric autoantibodies in ferrets naturally infected with helicobacter mustelae.infection with helicobacter pylori has been associated with induction of autoantibodies that cross-react with the gastric mucosa. there have been discordant reports as to whether or not these autoantibodies arise due to molecular mimicry between h. pylori and host cell antigens on parietal cells. in this study, we investigated whether molecular mimicry by h. mustelae causes autoantibodies in infected ferrets. serum from h. mustelae-infected ferrets reacted with parietal cells in the ferret gastr ...200111254638
the 26-kilodalton, ahpc homologue, of helicobacter pylori is also produced by other helicobacter species.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.200111328365
helicobacter mustelae lipid a structure differs from that of helicobacter pylori.the lipid a structure of the gram-negative bacterium helicobacter mustelae, a ferret gastric pathogen responsible for the onset of gastric diseases in its host, was investigated. two variant lipid a structures were found in the same strain. one structure contained a bisphosphorylated beta-(1-->6)-linked d-glucosamine backbone disaccharide with hydroxytetradecanoic acid in amide linkages. unlike the structure described for the lipid a of the related human helicobacter pylori gastric pathogen, whi ...200111418100
are goats naturally resistant to gastric helicobacter infection?gastric helicobacter species are widespread and have been reported in wild and domestic mammals of different dietary habits such as humans, dogs, cats, macaques, mice, cheetahs, ferrets, swine and cattle. all have been associated with gastric pathologies. recently, gastric helicobacter species were shown to be widespread in cattle and swine in europe, and there is a report of helicobacter pylori in sheep in italy. however, there are no reports of helicobacter infection in the goat, another impor ...200211731164
helicobacter pylori and food products: a public health problem.helicobacter pylori is a major human pathogen causing gastritis and chronic superficial infection (csg). it colonizes the stomach of more than 50% of humans and causes disease. this microorganism is associated with the gastric antral epithelium in patients with active chronic gastritis, peptic (gastric) or duodenal ulcers, and gastric adenocarcinoma h. pylori is present in feces, sewage, and water but is killed by routine chlorination. therefore, in developing countries, consumption of sewage-co ...200415156039
molecular identification of helicobacter dna present in human colorectal adenocarcinomas by 16s rdna pcr amplification and pyrosequencing analysis.seroepidemiological studies have indicated that helicobacter pylori infection might be a possible risk factor for colorectal adenocarcinoma (crc) development. however, limited information is available as to whether or not helicobacter species are present in crc tissues. in this study the presence of helicobacter dna in 77 crc biopsies was investigated by means of a helicobacter species-specific 16s rdna pcr assay and real-time dna pyrosequencing of the 16s rdna variable v3 region. pyrosequencing ...200516192433
metal-responsive gene regulation and metal transport in helicobacter species.helicobacter species are among the most successful colonizers of the mammalian gastrointestinal and hepatobiliary tract. colonization is usually lifelong, indicating that helicobacter species have evolved intricate mechanisms of dealing with stresses encountered during colonization of host tissues, like restriction of essential metal ions. the recent availability of genome sequences of the human gastric pathogen helicobacter pylori, the murine enterohepatic pathogen helicobacter hepaticus and th ...200717294126
random mutagenesis to identify novel helicobacter mustelae virulence factors.helicobacter mustelae is a gastric pathogen of ferrets, where it causes disorders similar to those caused by helicobacter pylori in humans. the h. mustelae ferret model therefore has potential for the in vivo study of helicobacter pathogenesis in general. in this study a library of 500 individual h. mustelae mutants was generated using an in vitro random insertion mutagenesis technique. mutants were subsequently tested for motility and adherence, and 43 of the 500 mutants tested were found to be ...200717316371
characterization of nikr-responsive promoters of urease and metal transport genes of helicobacter mustelae.the nikr protein is a nickel-responsive regulator, which in the gastric pathogen helicobacter pylori controls expression of nickel-transporters and the nickel-cofactored urease acid resistance determinant. although nikr-dna interaction has been well studied, the helicobacter nikr operator site remains poorly defined. in this study we have identified the nikr operators in the promoters of two inversely nickel-regulated urease operons (ureab and urea2b2) in the ferret pathogen helicobacter mustela ...201019894125
an abc transporter and a tonb ortholog contribute to helicobacter mustelae nickel and cobalt acquisition.the genomes of helicobacter species colonizing the mammalian gastric mucosa (like helicobacter pylori) contain a large number of genes annotated as iron acquisition genes but only few nickel acquisition genes, which contrasts with the central position of nickel in the urease-mediated acid resistance of these gastric pathogens. in this study we have investigated the predicted iron and nickel acquisition systems of the ferret pathogen helicobacter mustelae. the expression of the outer membrane pro ...201020643857
nonprimate animal models of h. pylori infection.ever since the realization that helicobacter pylori was intimately associated with the development of gastritis and peptic ulcer disease in humans, there has been a need for a simple animal model in which modes of pathogenicity, transmission, immunization, and chemotherapeutic intervention can be evaluated. whereas small animals such as mice and rats are particularly well suited as experimental hosts for many infections, early studies suggested that h. pylori had a very narrow host range that di ...199721351037
the nonhuman primate model for h. pylori infection.helicobacter pylori establishes chronic infections in the human gastric mucosa that can last for decades, and that are a major cause of gastritis and peptic ulcer disease (pud) and a risk factor for gastric cancer. the importance of h. pylori as a human pathogen has led to major efforts to understand its interactions with its human host, including the development and use of various animal models. several heterologous models have been developed, including: 1. gnotobiotic newborn piglets, which ar ...199721351038
Displaying items 1 - 67 of 67