| 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 ... | 1992 | 1370432 |
| monoclonal antibodies against the native urease of helicobacter pylori: synergistic inhibition of urease activity by monoclonal antibody combinations. | monoclonal antibodies (mabs) against the native urease of helicobacter pylori nctc 11637 were found to clearly inhibit the urease activity. interestingly, synergistic inhibition by two mabs recognizing different subunits was also observed. ten mabs were produced and classified as two isotypes of the immunoglobulin g (igg) subclass, igg1, and igg2a. western blot (immunoblot) analysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that five mabs recognized the large subunit ... | 1992 | 1383158 |
| biochemical studies of helicobacter mustelae fatty acid composition and flagella. | the fatty acid compositions of helicobacter mustelae whole cells, isolated phospholipids, and isolated lipopolysaccharides were analyzed by gas-liquid chromatography. major phospholipid fatty acids were c16:0, c18:0, c18:1, and c19:0 cyc. in isolated lipopolysaccharides, 3-oh-c16:0, 3-oh-c14:0, c14:0, c16:0, and c18:0 were found. the lipid composition of h. mustelae thus showed pronounced differences from that of h. pylori. flagella were purified by mechanical shearing and centrifugation steps. ... | 1992 | 1548093 |
| pyloric adenocarcinoma in a ferret. | pyloric adenocarcinoma was diagnosed in a ferret with clinical signs of gastric distention. the development of this tumor may be related to helicobacter mustelae infection in the gastric mucosa of ferrets. pyloric adenocarcinoma has only recently been reported in ferrets and should be considered as a differential diagnosis for gastric distention in this species. | 1992 | 1607319 |
| an ultrastructural study of helicobacter mustelae and evidence of a specific association with gastric mucosa. | the ultrastructure of helicobacter mustelae, a natural inhabitant of the ferret stomach, has been studied and compared with the human gastroduodenal pathogen h. pylori. h. mustelae is a short, slightly curved rod, 2 microns x 0.5 micron, with four or more sheathed flagella. the most common flagellar configuration is a single flagellum at one terminus, bipolar arrangement at the other end and a lateral flagellum. dense inclusion bodies were observed below the flagellar insertion sites. it is sugg ... | 1992 | 1613782 |
| evaluation of fingerprinting methods for identification of helicobacter pylori strains. | variation amongst strains of helicobacter pylori was examined by 35s-methionine-labelled protein sds-page (radio-page), immunoblot and dna fingerprinting techniques. these methods allowed discrimination amongst isolates and showed total correlation. pig and baboon gastric helicobacter pylori-like organisms were found to be very similar to helicobacter pylori by both radio-page and immunoblotting, whereas a helicobacter mustelae isolate was markedly different. the hindiii restriction endonuclease ... | 1991 | 1687029 |
| 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 ... | 1990 | 1698260 |
| phylogeny of helicobacter felis sp. nov., helicobacter mustelae, and related bacteria. | strain cs1t (t = type strain) is a gram-negative, microaerophilic, urease-positive, spiral-shaped bacterium that was isolated from the gastric mucosa of a cat. additional strains which possessed biochemical and ultrastructural characteristics similar to those of strain cs1t were isolated from the gastric mucosa of cats and dogs. the guanine-plus-cytosine content of the dna of strain cs1t was 42.5 mol%. the 16s rrna sequences of strain cs1t, strain ds3 (a spiral-shaped isolate from a dog), and he ... | 1991 | 1704791 |
| helicobacter muridarum sp. nov., a microaerophilic helical bacterium with a novel ultrastructure isolated from the intestinal mucosa of rodents. | helical organisms with novel ultrastructural characteristics were isolated from the intestinal mucosa of rats and mice. these bacteria were characterized by the presence of 9 to 11 periplasmic fibers which appeared as concentric helical ridges on the surface of each cell. the cells were motile with a rapid corkscrewlike motion and had bipolar tufts of 10 to 14 sheathed flagella. the bacteria were microaerophilic, nutritionally fastidious, and physiologically similar to helicobacter species and w ... | 1992 | 1736969 |
| 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 ... | 1991 | 1833810 |
| 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. | 1991 | 1879950 |
| inhibition of acid secretion from parietal cells by non-human-infecting helicobacter species: a factor in colonization of gastric mucosa? | helicobacter pylori has been shown to produce a protein that inhibits acid secretion from parietal cells. we have examined other non-human-infecting helicobacter species for this property by measuring the uptake of [14c]aminopyrine into rabbit parietal cells as an indirect assessment of acid secretion. helicobacter felis and an isolate from a rhesus monkey were shown to inhibit acid secretion. isolates of helicobacter mustelae gave variable responses. whole bacteria and cell-free sonicates impai ... | 1991 | 1894369 |
| 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 ... | 1991 | 1925314 |
| isolation and biochemical and molecular analyses of a species-specific protein antigen from the gastric pathogen helicobacter pylori. | a protein of mr 26,000 which was present in large quantities in extracts of cells of helicobacter pylori was purified to homogeneity by ammonium sulfate precipitation followed by gel filtration and reversed-phase chromatography or anion-exchange chromatography. the protein appeared to be associated with the soluble fraction of the cell, and antibodies raised against the protein were reactive with whole-cell lysates of a variety of h. pylori strains in a simple immunodot blot assay. this reaction ... | 1991 | 1987145 |
| 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. | 1991 | 2007648 |
| helicobacter mustelae-induced gastritis and elevated gastric ph in the ferret (mustela putorius furo). | helicobacter mustelae has been cultured from the stomachs of ferrets with chronic gastritis; the lesions in the stomach have many of the same histological features seen in h. pylori gastritis in humans. to determine whether h. mustelae-negative ferrets with normal gastric mucosa were susceptible to colonization and whether gastritis developed after infection, four h. mustelae-negative ferrets treated with cimetidine were inoculated orally on two successive days with 3 ml (1.5 x 10(8) cfu) of h. ... | 1991 | 2037349 |
| 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 ... | 1990 | 2365188 |
| 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 ... | 1990 | 2393285 |
| 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 ... | 1990 | 2406141 |
| isolation of a campylobacter-like organism from healthy syrian hamsters (mesocricetus auratus). | a campylobacter-like organism was isolated from the ilea of normal hamsters. the organism was isolated from an ileal homogenate which was passed through a filter (0.65-micron pore size) and cultured on blood-agar plates in a microaerophilic atmosphere at 37 degrees c. pinpoint translucent colonies were first observed after 120 h of incubation. the isolated organism measured 2.0 to 3.5 microns in length (excluding flagella) by 0.17 to 0.25 micron in width and typically had a single terminal sheat ... | 1989 | 2681250 |
| 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 ... | 1989 | 2745703 |
| 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 ... | 1988 | 3169994 |
| sepa, the major extracellular protein of shigella flexneri: autonomous secretion and involvement in tissue invasion. | in addition to ipa proteins and icsa, which are involved in entry into epithelial cells and intercellular spread, respectively, shigella secretes a 110 kda protein, designated sepa. we report the identification, cloning, and nucleotide sequence determination of the sepa gene, analysis of sepa secretion, and construction and characterization of a sepa mutant. the sepa gene is carried by the virulence plasmid and codes for a 150 kda precursor. upon secretion, which does not involve accessory prote ... | 1995 | 7476198 |
| lipid profiles of helicobacter pylori and helicobacter mustelae grown in serum-supplemented and serum-free media. | many of helicobacter species have been found to have novel cholesteryl glucosides (cgs). to study the biosynthetic mechanism of cgs, the lipid profiles of h. pylori and h. mustelae grown in serum-supplemented and cholesterol-restricted serum-free media were investigated. in contrast to the serum-supplemented state, helicobacters had less cgs in the serum-free state; a trace amount of cgs and no cg was detected in h. pylori and h. mustelae, respectively. the proportion of total and individual pho ... | 1995 | 7502681 |
| immunological specificity of helicobacter pylori urease and identification by immunological detection of its specific urease. | helicobacter pylori urease was recovered as a single peak by deae-sepharose column chromatography and sephacryl s-200 gel filtration. the purified urease was obtained by fast protein liquid chromatography using a mono q column. the purified urease preparation gave a single band in polyacrylamide gel disc electrophoresis. latex particles were sensitized with anti-urease immunoglobulin. the sensitized latex particles were agglutinated with the purified urease and by cell sonicates obtained from 55 ... | 1993 | 7505793 |
| long-term supplementation of canthaxanthin does not inhibit gastric epithelial cell proliferation in helicobacter mustelae-infected ferrets. | the effect of canthaxanthin (cx), a nonprovitamin a carotenoid, on gastric epithelial proliferation was studied in ferrets colonized with helicobacter mustelae, which causes a chronic gastritis and an increased gastric epithelial cell proliferation. seven spayed female ferrets were dosed by gavage with cx beadlets (50 mg/kg body wt, 5 d/wk) over 2 y, whereas seven control animals were given placebo beadlets. at the end of the 2-y-period, ferrets were killed, and gastric tissues were obtained fro ... | 1995 | 7562083 |
| 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 ... | 1995 | 7634423 |
| construction and characterization of an isogenic urease-negative mutant of helicobacter mustelae. | helicobacter mustelae infects the ferret stomach and provides an opportunity to study pathogenic determinants of a helicobacter species in its natural host. we constructed an isogenic urease-negative mutant of h. mustelae which produced no detectable urease and showed a reduced acid tolerance. this mutant provides an opportunity to further evaluate the role of urease in the pathogenesis of helicobacter infection. | 1995 | 7642313 |
| inability of an isogenic urease-negative mutant stain of helicobacter mustelae to colonize the ferret stomach. | eight ferrets specific-pathogen-free for helicobacter mustelae were given, per dose, approximately 3.0 x 10(7) cfu of either the wild-type parent strain of h. mustelae (nctc 12032) (two ferrets) the isogenic urease-negative mutant strain of h. mustelae (10::tn3km) (four ferrets), or sterile culture broth (two ferrets). infection status was monitored by endoscopic gastric biopsy for urease activity, histopathology, and culture and by serology at 3, 6, 10, and 21 weeks. all ferrets were necropsied ... | 1995 | 7642314 |
| 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. | 1995 | 7657097 |
| gastric disease in ferrets: effects of helicobacter mustelae, nitrosamines and reconstructive gastric surgery. | animal models are being used to study the mechanisms by which helicobacter spp. induce gastric disease. to assess the effects of a natural gastric pathogen, helicobacter mustelae, in the development of chronic gastritis, premalignancy and cancer, the ferret model was studied under natural and experimental conditions. | 1994 | 7735938 |
| 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 ... | 1995 | 7768796 |
| 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 ... | 1995 | 7790085 |
| urease-mediated destruction of bacteria is specific for helicobacter urease and results in total cellular disruption. | the survival of helicobacter mustelae, proteus mirobilis, escherichia coli and campylobacter jejuni in the presence of urea and citrate at ph 6.0 was examined. h. mustelae, which has urease activity similar to h. pylori, had a markedly reduced survival, median 2.5% (0-78%) (p < 0.001) when incubated under these conditions. only 7% of the ammonia produced by h. mustelae urease activity was recovered from the buffer, a similar percentage to that previously reported with h. pylori. none of the othe ... | 1994 | 7866348 |
| non-motile mutants of helicobacter pylori and helicobacter mustelae defective in flagellar hook production. | flagellar hooks were purified from helicobacter pylori and helicobacter mustelae. the 70 x 16 nm h. pylori hook was composed of flge subunits of 78kda, while the 72 x 16 nm h. mustelae hook was composed of 87 kda subunits. n-terminal sequence was obtained for the flge proteins of both species, and for an internal h. mustelae flge peptide. degenerate oligonucleotide primers allowed amplification of a 1.2 kb fragment from the h. mustelae chromosome, which carried part of the flge gene. the corresp ... | 1994 | 7891557 |
| genome conservation in helicobacter mustelae as determined by pulsed-field gel electrophoresis. | genomic dna from 15 strains of helicobacter mustelae was subjected to pulsed-field gel electrophoresis (pfge) after digestion with paci and sfii. h. mustelae genome dna appeared very similar in all strains examined, whether isolated from ferrets or mink or from animals bred in either the usa or in the uk. the h. mustelae genome size was estimated to be 1.7 mb, similar in size to that of h. pylori. a minor difference in paci pfge pattern and genome size was observed between rifampicin-resistant a ... | 1994 | 8013879 |
| 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 ... | 1994 | 8170397 |
| [mucinase activity of helicobacter pylori: application of simplified mucinase test]. | we conducted the simplified mucinase tests about helicobacters (helicobacter pylori, helicobacter felis and helicobacter mustelae) and campylobacter jejuni, positive controls were pseudomonas maltophilia and pseudomonas cepacia. h. pylori, h. felis and c. jejuni showed low resolution activities for hog gastric mucin, however h. mustelae had no detectable the activities. this enzymatic activity varies considerably by cultural condition of h. pylori, therefore it is difficult to compare the activi ... | 1993 | 8283626 |
| helicobacter acinonyx sp. nov., isolated from cheetahs with gastritis. | four strains of a novel helicobacter species were isolated from the stomachs of cheetahs (acinonyx jubilatus) with gastritis. these isolates were phenotypically similar to helicobacter pylori. the isolates were gram-negative, spiral bacteria which grew under microaerophilic conditions at 37 degrees c, but not at 25 or 42 degrees c, and produced urease, catalase, oxidase, alkaline phosphatase, and gamma-glutamyl transpeptidase. the isolates did not ferment glucose, mannitol, inositol, sorbitol, r ... | 1993 | 8379970 |
| 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. | 1993 | 8380398 |
| 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, ... | 1993 | 8403224 |
| a neutrophil chemotactic factor present in h. pylori but absent in h. mustelae. | this study was designed to compare the capabilities of helicobacter pylori and helicobacter mustelae to generate neutrophil chemotactic activity (nca) in vitro. h. pylori and h. mustelae were grown in parallel cultures under identical conditions. the cultures were washed and transferred to saline solution for 3 hr to avoid detecting nonspecific chemotactic activity from culture media. supernatants were subjected to size-exclusion hplc. all peaks from hplc were collected and assayed for nca. peak ... | 1993 | 8420746 |
| development of a 14c-urea breath test in ferrets colonised with helicobacter mustelae: effects of treatment with bismuth, antibiotics, and urease inhibitors. | a 14c-urea breath test analogous to its clinical counterpart is described for use in ferrets naturally or experimentally infected with helicobacter mustelae. the test is performed within a sealed glass metabolism chamber through which air is drawn at a constant rate and expired breath collected into sodium hydroxide. peak 14co2 production occurred approximately 1 hour after substrate administration. both inter- and intra-animal responses were highly reproducible, with mean coefficients of variat ... | 1993 | 8432469 |
| 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 ... | 1993 | 8449568 |
| potent inhibitory action of the gastric proton pump inhibitor lansoprazole against urease activity of helicobacter pylori: unique action selective for h. pylori cells. | the gastric proton pump inhibitor lansoprazole, its active analog ag-2000, and omeprazole dose dependently inhibited urease activity extracted with distilled water from helicobacter pylori cells; the 50% inhibitory concentrations were between 3.6 and 9.5 microm, which were more potent than those of urease inhibitors, such as acetohydroxamic acid, hydroxyurea, and thiourea. these compounds also inhibited urease activity in intact cells of h. pylori and helicobacter mustelae but did not inhibit ur ... | 1993 | 8494373 |
| 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 ... | 1993 | 8500901 |
| 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 ... | 1993 | 8501031 |
| 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 ... | 1995 | 8541035 |
| 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 ... | 1995 | 8563056 |
| 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 hear ... | 1996 | 8573490 |
| helicobacter mustelae-associated hypergastrinemia in ferrets (mustela putorius furo). | to determine whether ferrets naturally infected with helicobacter mustelae were hypergastrinemic, compared with ferrets that were specific-pathogen-free (spf) for h mustelae. | 1996 | 8633798 |
| 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 ... | 1996 | 8697675 |
| ex-vivo treatment of gastric helicobacter infection by photodynamic therapy. | attempts to develop pdt for eradication of helicobacter infection have only been successful in vitro. we have investigated the effect of topical sensitization (except ala) of helicobacter mustelae on explanted ferret gastric mucosa using one of five sensitizers (methylene blue (mb), toluidine blue o (tbo), phthalocyanine, haematoporphyrin derivative and 5-aminolavulinic acid), followed by irradiation with an appropriately tuned copper vapour pumped dye laser. a 90% reduction in counts of bacteri ... | 1996 | 8725054 |
| 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 ... | 1996 | 8730255 |
| 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. | 1996 | 8964402 |
| 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 ... | 1997 | 9125590 |
| 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 ... | 1997 | 9163879 |
| 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 ... | 1997 | 9212752 |
| the lipopolysaccharide of helicobacter mustelae type strain atcc 43772 expresses the monofucosyl a type 1 histo-blood group epitope. | the lipopolysaccharide of helicobacter mustelae type strain atcc 43772 was obtained by phenol-water extraction of bacterial cells. structural investigations were made on the lipid a free saccharide moiety released from the lipopolysaccharide by mild acetic acid hydrolysis. nuclear magnetic resonance, gas liquid chromatography-mass spectrometry and fast atom bombardment-mass spectrometry were employed in the characterization of products from chemical manipulations. a monoclonal antibody specific ... | 1997 | 9297827 |
| use of pulsed-field gel electrophoresis to determine genomic diversity in strains of helicobacter hepaticus from geographically distant locations. | in 1992 a helical microorganism associated with chronic active hepatitis and a high incidence of hepatocellular tumors was identified in the hepatic parenchyma of a/jcr mice. by using biochemical tests, phenotypic characterization, and 16s rrna gene sequence analysis, the organism was classified as a novel helicobacter species and named helicobacter hepaticus. recent surveys completed in our laboratory indicate that h. hepaticus is widespread in academic and commercial mouse colonies. the aim of ... | 1997 | 9350747 |
| conservation and diversity of the helicobacter pylori copper-transporting atpase gene (copa) sequence among helicobacter species and campylobacter species detected by pcr and rflp. | helicobacter pylori is a causative pathogen of such human stomach diseases as chronic type b gastritis, ulcer, and possibly gastric carcinoma. as a cofactor in various redox enzymes and an essential trace metal required for the synthesis of metalloproteins, copper might play a role in the pathogenesis of h. pylori. a gene, copa, associated with copper transport, has been isolated from h. pylori ua802. in this study, conservation and diversity of this gene were analyzed among some helicobacter an ... | 1996 | 9398888 |
| natural and experimental helicobacter mustelae reinfection following successful antimicrobial eradication in ferrets. | recrudescence or reinfection may occur after eradication of helicobacter pylori in humans. | 1996 | 9398911 |
| 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. | 1996 | 9398912 |
| promotion of ulcerative duodenitis in young ferrets by oral immunization with helicobacter mustelae and muramyl dipeptide. | the purpose of this study was to determine whether oral immunization of ferret kits with a whole-cell sonicate of helicobacter mustelae lysate (hml) and the adjuvant muramyl dipeptide (mdp) would reduce the incidence of natural colonization with h. mustelae and the extent of helicobacter-associated gastritis by enhancing the host mucosal immune response. | 1997 | 9432331 |
| properties of the p-type atpases encoded by the copap operons of helicobacter pylori and helicobacter felis. | the cop operons of helicobacter pylori and helicobacter felis were cloned by gene library screening. both operons contain open reading frames for a p-type ion pump (copa) with homology to cd2+ and cu2+ atpases and a putative ion binding protein (copp), the latter representing a copz homolog of the copyzab operon of enterococcus hirae. the predicted copa atpases contained an n-terminal gmxcxxc ion binding motif and a membrane-associated cpc sequence. a synthetic n-terminal peptide of the h. pylor ... | 1998 | 9440521 |
| mice are protected from helicobacter pylori infection by nasal immunization with attenuated salmonella typhimurium phopc expressing urease a and b subunits. | live salmonella typhimurium phopc bacteria were tested as mucosal vaccine vectors to deliver helicobacter pylori antigens. the genes encoding the a and b subunits of h. pylori urease were introduced into s. typhimurium phopc and expressed under the control of a constitutive tac promoter (tac-ureab) or a two-phase t7 expression system (ct7-ureab). both recombinant salmonella strains expressed the two urease subunits in vitro and were used to nasally immunize balb/c mice. the plasmid carrying ct7- ... | 1998 | 9453612 |
| helicobacter pylori porcdab and oordabc genes encode distinct pyruvate:flavodoxin and 2-oxoglutarate:acceptor oxidoreductases which mediate electron transport to nadp. | helicobacter pylori, a major cause of human gastric disease, is a microaerophilic bacterium that contains neither pyruvate nor 2-oxoglutarate dehydrogenase activity. previous studies (n. j. hughes, p. a. chalk, c. l. clayton, and d. j. kelly, j. bacteriol. 177:3953-3959, 1995) have indicated that the major routes for the generation of acetyl coenzyme a (acetyl-coa) and succinyl-coa are via pyruvate:flavodoxin oxidoreductase (por) and 2-oxoglutarate:acceptor oxidoreductase (oor), respectively. th ... | 1998 | 9495749 |
| 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. | 1998 | 9516389 |
| 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, ... | 1998 | 9534968 |
| identification of a novel enteric helicobacter species in a kitten with severe diarrhea. | a previously undescribed helicobacter sp. was recovered from a cat with severe diarrhea. based upon the absence of any other identifiable cause of diarrhea, this helicobacter may be involved in the development of the disease signs. the organism could not be cultured but was described on the basis of 16s rrna gene sequence analysis and morphology and appeared to be a new species, with helicobacter canis being the most genetically similar species. the presence of a diarrhea-inducing helicobacter i ... | 1998 | 9542907 |
| helicobacter pylori glutamine synthetase lacks features associated with transcriptional and posttranslational regulation. | helicobacter pylori urease, produced in abundance, is indispensable for the survival of h. pylori in animal hosts. urea is hydrolyzed by the enzyme, resulting in the liberation of excess ammonia, some of which neutralizes gastric acid. the remaining ammonia is assimilated into protein by glutamine synthetase (ec 6.3.1.2), which catalyzes the reaction: nh3 + glutamate + atp-->glutamine + adp + pi. we hypothesized that glutamine synthetase plays an unusually critical role in nitrogen assimilation ... | 1998 | 9573059 |
| growth and survival of helicobacter pylori in defined medium and susceptibility to brij 78. | the gastrointestinal pathogen helicobacter pylori requires supplementation with either fetal calf serum (fcs), bovine serum albumin (bsa), or (2,6-dimethyl)-beta-cyclodextrin (cd) for growth in a complex or defined medium. because the availability of medium in which all components were chemically defined would facilitate metabolic studies of h. pylori, growth of the type strain, atcc 43504, was compared in a defined medium with different growth additives. the dependency of h. pylori growth on fc ... | 1998 | 9574682 |
| presence of multiple "helicobacter heilmannii" strains in an individual suffering from ulcers and in his two cats. | circumstantial evidence suggests that "helicobacter heilmannii" infection is an example of zoonosis. the presence of "h. heilmannii" strains in a human subject with acute gastric erosions, in his two cats, and in two unrelated cats was analyzed, and the genetic relatedness of the human and feline strains was assessed. a 580-bp, pcr-amplified sequence of "h. heilmannii" urease b gene (ureb) obtained from biopsies from the human subject and his two cats was restricted with alui and cloned for sequ ... | 1998 | 9574707 |
| experimental helicobacter pylori infection induces antral gastritis and gastric mucosa-associated lymphoid tissue in guinea pigs. | humans infected with helicobacter pylori have abnormally low levels of the antioxidant vitamin c, which protects against the formation of carcinogenic nitrosamines, in gastric juice. guinea pigs, like humans and nonhuman primates, have a dietary requirement for vitamin c. as such, these species have gastrointestinal vitamin c transport systems not found in other animals. we have developed and characterized a guinea pig model of chronic gastric h. pylori infection with the rodent-adapted sydney s ... | 1998 | 9596724 |
| evidence for a conjugation-like mechanism of dna transfer in helicobacter pylori. | many strains of helicobacter pylori are naturally competent for transformation in vitro. since there is a high degree of genetic variation among h. pylori strains, we sought to determine whether mechanisms of dna exchange other than transformation exist in these organisms. studies were done with h. pylori cells that each were resistant to two different antibiotics; the procedure used involved mating of cells on plates or in broth, in the absence or presence of dnase. in each experiment, such mat ... | 1998 | 9603879 |
| the central, surface-exposed region of the flagellar hook protein flge of campylobacter jejuni shows hypervariability among strains. | in a previous study, we observed that monoclonal antibodies raised against the hook protein flge of campylobacter jejuni lio 36, isolate 5226, bound exclusively to this strain. the aim of this study was to elucidate the molecular basis for these binding specificities. the hook protein-encoding gene flge of c. jejuni was cloned in escherichia coli and sequenced. the flge genes of four additional c. jejuni strains were amplified by pcr and also sequenced. comparison of the deduced amino acid seque ... | 1998 | 9658019 |
| a euthymic hairless mouse model of helicobacter pylori colonization and adherence to gastric epithelial cells in vivo. | the hairless mouse strain ns:hr/icr was examined as a potential small animal model of helicobacter pylori colonization, adherence to gastric epithelial cells in vivo, and gastritis. among several small animals tested, ns:hr/icr mice proved to be the most highly susceptible to h. pylori infection. challenge with clinical isolates of h. pylori consisting of either phenotype i or ii (vaca and caga positive and negative, respectively) resulted in colonization by mucus-resident and epithelial cell-ad ... | 1998 | 9665970 |
| development of a pcr-restriction fragment length polymorphism assay using the nucleotide sequence of the helicobacter hepaticus urease structural genes ureab. | infection with helicobacter hepaticus causes chronic active hepatitis in certain strains of mice and is associated with hepatocellular carcinoma in a/jcr mice. like the gastric helicobacters, h. pylori and h. mustelae, h. hepaticus possesses a high level of urease activity. however, the h. hepaticus urease structural gene sequences have not been previously determined, and the role of the urease enzyme in colonization and in pathogenesis is not known. pcr was used to amplify a portion of the urea ... | 1998 | 9705372 |
| characterization of an acidic-ph-inducible stress protein (hsp70), a putative sulfatide binding adhesin, from helicobacter pylori. | the in vitro glycolipid binding specificity of the gastric pathogen helicobacter pylori is altered to include sulfated glycolipids (sulfatides) following brief exposure of the organism to acid ph typical of the stomach. this change is prevented by anti-hsp70 antibodies, suggesting that hsp70 may be a stress-induced surface adhesin, mediating sulfatide recognition. to facilitate investigation of the role of hsp70 in attachment, we have cloned and sequenced the h. pylori hsp70 gene (dnak). the hsp ... | 1998 | 9712748 |
| immunization against natural helicobacter pylori infection in nonhuman primates. | helicobacter pylori infection is widespread in some breeding groups of a rhesus monkey colony (71% h. pylori positive by 1 year), and the rate of seroconversion is also high. as a result, these groups can be used to test the safety and efficacy of an anti-h. pylori vaccine. nine-month-old female animals were randomized to receive either 8 mg of recombinant urease (rure) plus 25 microg of escherichia coli heat-labile enterotoxin (lt) (n = 26) or placebo plus lt (n = 29), given four times at 1-wee ... | 1998 | 9712786 |
| the helicobacter pylori urei protein is not involved in urease activity but is essential for bacterial survival in vivo. | we produced defined isogenic helicobacter pylori urei mutants to investigate the function of urei, the product of one of the genes of the urease cluster. the insertion of a cat cassette had a strong polar effect on the expression of the downstream urease genes, resulting in very weak urease activity. urease activity, measured in vitro, was normal in a strain in which urei was almost completely deleted and replaced with a nonpolar cassette. in contrast to previous reports, we thus found that the ... | 1998 | 9712811 |
| urease plays an important role in the chemotactic motility of helicobacter pylori in a viscous environment. | helicobacter pylori exhibits chemotactic responses to urea, flurofamide, acetohydroxamic acid, and sodium bicarbonate. in buffer, the chemotactic activities of a urease-positive strain were higher than those of the isogenic urease-negative strain. moreover, the chemotactic activities of the urease-positive strain were increased in a viscous solution containing 3% polyvinylpyrrolidone, whereas those of the urease-negative mutant were not. these results are in accordance with the fact that the mut ... | 1998 | 9746586 |
| experimental infection of mongolian gerbils with wild-type and mutant helicobacter pylori strains. | experimental helicobacter pylori infection was studied in mongolian gerbils with fresh human isolates that carry or do not carry caga (caga-positive or caga-negative, respectively), multiply passaged laboratory strains, wild-type strain g1.1, or isogenic urea, caga, or vaca mutants of g1.1. animals were sacrificed 1 to 32 weeks after challenge, the stomach was removed from each animal for quantitative culture, urease test, and histologic testing, and blood was collected for antibody determinatio ... | 1998 | 9746590 |
| isolation and identification of helicobacter spp. from canine and feline gastric mucosa. | it is known that virtually all healthy adult dogs and cats harbor spiral helicobacters in their gastric mucosa. three species, helicobacter felis, helicobacter bizzozeronii, and helicobacter salomonis have been isolated in vitro from the gastric mucosa of these animals. the aims of this study were to evaluate the efficacy of an isolation method for canine and feline gastric helicobacters that has been developed at the university of helsinki; to estimate the prevalence and distribution of these t ... | 1998 | 9758832 |
| helicobacter pylori containing only cytoplasmic urease is susceptible to acid. | helicobacter pylori, an important etiologic agent in a variety of gastroduodenal diseases, produces large amounts of urease as an essential colonization factor. we have demonstrated previously that urease is located within the cytoplasm and on the surface of h. pylori both in vivo and in stationary-phase culture. the purpose of the present study was to assess the relative contributions of cytoplasmic and surface-localized urease to the ability of h. pylori to survive exposure to acid in the pres ... | 1998 | 9784504 |
| scid/ncr mice naturally infected with helicobacter hepaticus develop progressive hepatitis, proliferative typhlitis, and colitis. | hepatitis, proliferative typhlitis, and colitis were characterized in young adult and older scid/ncr mice naturally infected with helicobacter hepaticus. liver lesions consisted of kupffer, ito, and oval cell hyperplasia along with multifocal to coalescing coagulative hepatocyte necrosis. numerous warthin-starry-positive bacteria were observed in the parenchyma, and there were minimal to mild accumulations of monocytic cells and neutrophils. proliferative typhlitis was characterized by moderate ... | 1998 | 9784560 |
| cancer-associated strains of helicobacter pylori stimulate dna synthesis in iec-6 cells. | to determine whether water extracts of helicobacter pylori strains, which express caga, can influence dna synthesis in untransformed intestinal epithelial cells in vitro. | 1998 | 9831404 |
| novel intestinal helicobacter species isolated from cotton-top tamarins (saguinus oedipus) with chronic colitis. | a disease similar to ulcerative colitis in humans has been identified in cotton-top tamarins (ctts) in captivity. the clinical signs include weight loss, diarrhea, and rectal bleeding with the pathological features and biochemical abnormalities of ulcerative colitis. approximately 25 to 40% of these animals develop colon cancer after 2 to 5 years of captivity. an infectious etiology has been proposed; however, no microbial agent to date has been identified. helicobacter spp. have been associated ... | 1999 | 9854080 |
| healthy cats are commonly colonized with "helicobacter heilmannii" that is associated with minimal gastritis. | gastric helicobacter infection in healthy pet cats is not well characterized. we performed endoscopy with gastric biopsy on 15 healthy pet cats that were rigorously screened to exclude underlying or concurrent diseases that might affect helicobacter colonization. gastric mucosa biopsy specimens were examined by histology, culture, and pcr for the presence of helicobacter infection and by histology for the presence of gastritis. of 15 cats, all but 1 had gastric helicobacter-like organisms (ghlos ... | 1999 | 9854088 |
| motility of helicobacter pylori is coordinately regulated by the transcriptional activator flgr, an ntrc homolog. | sigma54 is the subunit of bacterial rna polymerase that transcribes from promoters with enhancer elements bound by enhancer-binding proteins. by computer searches of helicobacter pylori genomic sequences, chromosomal gene disruption, and rna analyses, we have identified sigma54-recognized promoters that regulate transcription of flagellar basal body and hook genes, as well as the enhancer-binding protein flgr (flagellum regulator), a transactivating protein of the ntrc family. we demonstrate tha ... | 1999 | 9882675 |
| mimicry of blood group antigen a by helicobacter mustelae and h. pylori. | | 1999 | 9922339 |
| characterization of a culturable "gastrospirillum hominis" (helicobacter heilmannii) strain isolated from human gastric mucosa. | spiral organisms were isolated from an antral gastric mucosal biopsy specimen from a dyspeptic patient with gastritis. only corkscrew-shaped organisms resembling "gastrospirillum hominis" ("helicobacter heilmannii") but no helicobacter pylori-like organisms were seen in histological sections. h. pylori was not cultured from specimens from this patient. on the basis of biochemical reactions, morphology, ultrastructure, and 16s dna sequencing, the isolated "g. hominis" was shown to be a true helic ... | 1999 | 10074528 |
| isolation of helicobacter pylori genes that modulate urease activity. | helicobacter pylori urease, a nickel-requiring metalloenzyme, hydrolyzes urea to nh3 and co2. we sought to identify h. pylori genes that modulate urease activity by constructing php8080, a plasmid which encodes both h. pylori urease and the nixa nickel transporter. escherichia coli se5000 and dh5alpha transformed with php8080 resulted in a high-level urease producer and a low-level urease producer, respectively. an h. pylori dna library was cotransformed into se5000 (php8080) and dh5alpha (php80 ... | 1999 | 10198012 |
| essential role of helicobacter pylori gamma-glutamyltranspeptidase for the colonization of the gastric mucosa of mice. | constitutive expression of gamma-glutamyltranspeptidase (ggt) activity is common to all helicobacter pylori strains, and is used as a marker for identifying h. pylori isolates. helicobacter pylori ggt was purified from sonicated extracts of h. pylori strain 85p by anion exchange chromatography. the n-terminal amino acid sequences of two of the generated endo-proteolysed peptides were determined, allowing the cloning and sequencing of the corresponding gene from a genomic h. pylori library. the h ... | 1999 | 10200957 |
| serological discrimination of dogs infected with gastric helicobacter spp. and uninfected dogs. | characterization of the humoral immune responses of people to helicobacter pylori infection has facilitated the investigation of the host response to bacterial virulence factors and the development of sensitive and specific diagnostic tests. dogs are commonly infected with gastric helicobacter spp., but the presence of multiple helicobacter spp. and possible coinfection in individual dogs have complicated serological evaluation. evaluation of the antigenic homology of helicobacter spp. revealed ... | 1999 | 10203471 |
| recurrent "flexispira rappini" bacteremia in an adult patient undergoing hemodialysis: case report. | a blood culture from a 65-year-old febrile man undergoing hemodialysis revealed, 5 days after inoculation, an unusual gram-negative fusiform rod with darting motility. during another episode of fever 21 days later, this campylobacter-like organism was again recovered from three blood cultures and subcultured under an h2-enriched microaerobic atmosphere. the organism was catalase negative and oxidase positive and hydrolyzed urea rapidly. sodium dodecyl sulfate-polyacrylamide gel electrophoresis a ... | 1999 | 10203478 |
| molecular characterization of a flagellar export locus of helicobacter pylori. | motility of helicobacter species has been shown to be essential for successful colonization of the host. we have investigated the organization of a flagellar export locus in helicobacter pylori. a 7-kb fragment of the h. pylori ccug 17874 genome was cloned and sequenced, revealing an operon comprising an open reading frame of unknown function (orf03), essential housekeeping genes (iles and murb), flagellar export genes (flii and fliq), and a homolog to a gene implicated in virulence factor trans ... | 1999 | 10225855 |
| identification of virulence genes of helicobacter pylori by random insertion mutagenesis. | the complete genome of the gram-negative bacterial pathogen helicobacter pylori, an important etiological agent of gastroduodenal disease in humans, has recently been published. this sequence revealed that the putative products of roughly one-third of the open reading frames (orfs) have no significant homology to any known proteins. to be able to analyze the functions of all orfs, we constructed an integration plasmid for h. pylori and used it to generate a random mutant library in this organism ... | 1999 | 10225906 |
| a conventional beagle dog model for acute and chronic infection with helicobacter pylori. | helicobacter pylori has been widely recognized as an important human pathogen responsible for chronic gastritis, peptic ulcers, gastric cancer, and mucosa-associated lymphoid tissue (malt) lymphoma. little is known about the natural history of this infection since patients are usually recognized as having the infection only after years or decades of chronic disease. several animal models of h. pylori infection, including those with different species of rodents, nonhuman primates, and germ-free a ... | 1999 | 10338528 |
| rapid detection, by pcr and reverse hybridization, of mutations in the helicobacter pylori 23s rrna gene, associated with macrolide resistance. | a pcr-based reverse hybridization system (research prototype kit inno-lipa for h. pylori resistance) was developed and evaluated for simultaneous detection of 23s ribosomal dna point mutations, associated with macrolide resistance in helicobacter pylori. fifty-seven h. pylori strains (51 natural, 6 laboratory-derived artificial, 52 resistant, and 5 susceptible strains) were tested by pcr-lipa (detecting mutations a2115-->g, g2141-->a, a2142-->g, a2142-->c, a2143-->g, a2143-->c, and a2143-->t), d ... | 1999 | 10390244 |