| phase variation in helicobacter pylori lipopolysaccharide due to changes in the lengths of poly(c) tracts in alpha3-fucosyltransferase genes. | the lipopolysaccharide (lps) of helicobacter pylori expresses the lewis x (lex) and/or ley antigen. we have shown previously that h. pylori lps displays phase variation whereby an lex-positive strain yields variants with different lps serotypes, for example, lex plus ley or nonfucosylated polylactosamine. h. pylori has two alpha3-fucosyltransferase genes that both contain poly(c) tracts. we now demonstrate that these tracts can shorten or lengthen randomly, which results in reversible frameshift ... | 1999 | 10496917 |
| a phase variant of azospirillum lipoferum lacks a polar flagellum and constitutively expresses mechanosensing lateral flagella. | flagellation of a nonswimming variant of the mixed flagellated bacterium azospirillum lipoferum 4b was characterized by electron microscopy, and polyclonal antibodies were raised against polar and lateral flagellins. the variant cells lacked a polar flagellum due to a defect in flagellin synthesis and constitutively expressed lateral flagella. the variant cells were able to respond to conditions that restricted the rotation of lateral flagella by producing more lateral flagella, suggesting that ... | 1999 | 10508112 |
| molecular cloning and characterization of the helicobacter pylori flid gene, an essential factor in flagellar structure and motility. | helicobacter pylori colonizes the human stomach and can cause gastroduodenal disease. flagellar motility is regarded as a major factor in the colonizing ability of h. pylori. the functional roles of flagellar structural proteins other than flaa, flab, and flge are not well understood. the flid operon of h. pylori consists of flag, flid, and flis genes, in the order stated, under the control of a sigma(28)-dependent promoter. in an effort to elucidate the function of the flid protein, a hook-asso ... | 1999 | 10559162 |
| 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 |
| 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 |
| 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 |
| identification of a novel penicillin-binding protein from helicobacter pylori. | the helicobacter pylori genome encodes four penicillin-binding proteins (pbps). pbps 1, 2, and 3 exhibit similarities to known pbps. the sequence of pbp 4 is unique in that it displays a novel combination of two highly conserved pbp motifs and an absence of a third motif. expression of pbp 4, but not pbp 1, 2, or 3, is significantly increased during mid- to late-log-phase growth. | 1999 | 10438788 |
| 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 |
| replication-defective adenovirus infection reduces helicobacter felis colonization in the mouse in a gamma interferon- and interleukin-12-dependent manner. | helicobacter infection leads to chronic inflammation of the stomach. although the infection persists in spite of an immune response, animal studies have shown that adjuvant-based oral vaccines can protect against infection and even eliminate established infection. these vaccines are thought to induce a th2 immune response, counterbalancing the th1 response seen with natural infections. as a prelude to using adenovirus vectors carrying cytokine genes to modulate the immune response to established ... | 1999 | 10456897 |
| mutational analysis of genes encoding the early flagellar components of helicobacter pylori: evidence for transcriptional regulation of flagellin a biosynthesis. | we investigated the roles of flif, flis, flhb, fliq, flig, and flii of helicobacter pylori, predicted by homology to encode structural components of the flagellar basal body and export apparatus. mutation of these genes resulted in nonmotile, nonflagellate strains. western blot analysis showed that all the mutants had considerably reduced levels of both flagellin subunits and of flge, the flagellar hook protein. rna slot blot hybridization showed reduced levels of flaa mrna, indicating that tran ... | 2000 | 10960117 |
| molecular characterization of two-component systems of helicobacter pylori. | two-component systems are frequently involved in the adaptation of bacteria to changing environmental conditions at the level of transcriptional regulation. here we report the characterization of members of the two-component systems of the gastric pathogen helicobacter pylori deduced from the genome sequence of strain 26695. we demonstrate that the response regulators hp166, hp1043, and hp1021 have essential functions, as disruption of the corresponding genes is lethal for the bacteria, irrespec ... | 2000 | 10735847 |
| the haemophilus influenzae hia adhesin is an autotransporter protein that remains uncleaved at the c terminus and fully cell associated. | nontypeable haemophilus influenzae is a gram-negative commensal organism that is commonly associated with localized respiratory tract disease. the pathogenesis of disease begins with colonization of the nasopharynx, a process that likely depends on bacterial adherence to respiratory epithelial cells. hia is the major adhesin expressed by a subset of nontypeable h. influenzae strains and promotes efficient adherence to a variety of human epithelial cell lines. based on previous work, hia is trans ... | 2000 | 11029419 |
| 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 |
| isolation of recombinant protective helicobacter pylori antigens. | a total of seven clones producing both new and previously described helicobacter pylori proteins were isolated from a library of h. pylori genomic dna. the screening approach by which these proteins were detected relied on the use of antisera raised in mice vaccinated with helicobacter felis sonicate plus cholera toxin, a regimen which protects mice from h. pylori challenge. this strategy was designed to maximize the possibility of obtaining antigens which might be capable of conferring protecti ... | 1999 | 10456921 |
| 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 |
| hp0333, a member of the dpra family, is involved in natural transformation in helicobacter pylori. | helicobacter pylori is naturally competent for dna transformation, but the mechanism by which transformation occurs is not known. for haemophilus influenzae, dpra is required for transformation by chromosomal but not plasmid dna, and the complete genomic sequence of h. pylori 26695 revealed a dpra homolog (hp0333). examination of genetic databases indicates that dpra homologs are present in a wide variety of bacterial species. to examine whether hp0333 has a function similar to dpra of h. influe ... | 1999 | 10482496 |
| ranitidine bismuth citrate and clarithromycin, alone or in combination, for eradication of helicobacter mustelae infection in ferrets. | to determine whether ranitidine bismuth citrate, clarithromycin, or a combination of ranitidine bismuth citrate and clarithromycin would be efficacious in eradication of helicobacter mustelae infection in ferrets. | 1999 | 10791942 |
| misidentifying helicobacters: the helicobacter cinaedi example. | whole-cell protein electrophoresis and biochemical examination by means of a panel of 64 tests were used to identify 14 putative helicobacters to the species level. the results were confirmed by means of dna-dna hybridization experiments and were used to discuss misidentification of helicobacters based on 16s rrna gene sequence data. the data indicated that comparison of near-complete 16s ribosomal dna sequences does not always provide conclusive evidence for species level identification and may ... | 2000 | 10834986 |
| helicobacter mesocricetorum sp. nov., a novel helicobacter isolated from the feces of syrian hamsters. | a spiral-shaped bacterium with bipolar, single, nonsheathed flagella was isolated from the feces of syrian hamsters. the bacterium grew as a thin spreading film at 37 degrees c under microaerobic conditions, did not hydrolyze urea, was positive for catalase and alkaline phosphatase, reduced nitrate to nitrite, did not hydrolyze hippurate, and was sensitive to nalidixic acid but resistant to cephalothin. sequence analysis of the 16s rrna gene and biochemical and phenotypic criteria indicate that ... | 2000 | 10790105 |
| the spirochete flaa periplasmic flagellar sheath protein impacts flagellar helicity. | spirochete periplasmic flagella (pfs), including those from brachyspira (serpulina), spirochaeta, treponema, and leptospira spp., have a unique structure. in most spirochete species, the periplasmic flagellar filaments consist of a core of at least three proteins (flab1, flab2, and flab3) and a sheath protein (flaa). each of these proteins is encoded by a separate gene. using brachyspira hyodysenteriae as a model system for analyzing pf function by allelic exchange mutagenesis, we analyzed purif ... | 2000 | 11073915 |
| direct analysis and identification of helicobacter and campylobacter species by maldi-tof mass spectrometry. | campylobacter jejuni, campylobacter fetus, and campylobacter coli were compared with helicobacter pylori and helicobacter mustelae by direct analysis of individual cultured colonies in 50% methanol-water with a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (maldi-tof ms). h. pylori and campylobacter species from blood agar culture produced unique, complex spectra with over 25 different ions in mass/charge (m/z) range from 2,000 to 62,000. a biomarker for h. pylori ... | 1999 | 10464475 |
| comparison of iron uptake in different helicobacter species. | comparison of iron uptake of four helicobacter species (helicobacter pylori, helicobacter felis, helicobacter acinonyx, and helicobacter mustelae), associated with various degrees of gastritis in their respective host, with five other species which colonize the intestinal tract of various animals (helicobacter fennelliae, helicobacter cinaedi, helicobacter muridarum, helicobacter bilis, and helicobacter hepaticus), demonstrated that the iron acquisition system differed according to the ecologica ... | 1999 | 10540911 |
| urease-based mucosal immunization against helicobacter heilmannii infection induces corpus atrophy in mice. | mucosal immunization with helicobacter heilmannii urease b or helicobacter pylori urease, given nasally with cholera toxin, protects balb/c mice against h. heilmannii infection and significantly reduces a preexisting infection. however, immunization aggravates gastric corpus atrophy. our results underline the necessity of defining immunization regimens that do not enhance mucosal damage. | 1999 | 10531292 |
| performance criteria of dna fingerprinting methods for typing of helicobacter pylori isolates: experimental results and meta-analysis. | typing systems are used to discriminate between isolates of helicobacter pylori for epidemiological and clinical purposes. discriminatory power and typeability are important performance criteria of typing systems. discriminatory power refers to the ability to differentiate among unrelated isolates; it is quantitatively expressed by the discriminatory index (di). typeability refers to the ability of the method to provide an unambiguous result for each isolate analyzed; it is quantitatively expres ... | 1999 | 10565934 |
| rapid identification of campylobacter, arcobacter, and helicobacter isolates by pcr-restriction fragment length polymorphism analysis of the 16s rrna gene. | a rapid two-step identification scheme based on pcr-restriction fragment length polymorphism (pcr-rflp) analysis of the 16s rrna gene was developed in order to differentiate isolates belonging to the campylobacter, arcobacter, and helicobacter genera. for 158 isolates (26 reference cultures and 132 clinical isolates), specific rflp patterns were obtained and species were successfully identified by this assay. | 1999 | 10565952 |
| transcriptional analysis of major heat shock genes of helicobacter pylori. | the transcriptional organization and heat inducibility of the major heat shock genes hrca, dnak, dnaj, groel, and htpg were analyzed on the transcriptional level in helicobacter pylori strain 69a. the strongly heat-induced dnak operon was found to be tricistronic, consisting of the genes hrca, grpe, and dnak. the dnaj gene specified one monocistronic mrna which was also heat inducible. the genes groes and groel were transcribed as one strongly heat-inducible bicistronic mrna which exhibited exac ... | 2000 | 10894735 |
| switching of flagellar motility in helicobacter pylori by reversible length variation of a short homopolymeric sequence repeat in flip, a gene encoding a basal body protein. | the genome of helicobacter pylori contains numerous simple nucleotide repeats that have been proposed to have regulatory functions and to compensate for the conspicuous dearth of master regulatory pathways in this highly host-adapted bacterium. h. pylori strain 26695, whose genomic sequence was determined by the institute for genomic research (tigr), contains a repeat of nine cytidines in the flip flagellar basal body gene that splits the open reading frame in two parts. in this work, we demonst ... | 2000 | 10899861 |
| expression of the helicobacter pylori urei gene is required for acidic ph activation of cytoplasmic urease. | urei encodes an integral cytoplasmic membrane protein. it is present in the urease gene cluster of helicobacter pylori and is essential for infection and acid survival, but its role is unknown. to determine the function of urei protein, we produced h. pylori urei deletion mutants and measured the ph dependence of urease activity of intact and lysed bacteria and the effect of urea on the membrane potential. we also determined urei expression, urease activity, and the effect of urea on membrane po ... | 2000 | 10639406 |
| helicobacter felis infection is associated with lymphoid follicular hyperplasia and mild gastritis but normal gastric secretory function in cats. | the relationship of helicobacter felis, a bacterium observed in the stomachs of cats, to gastric disease is unclear. the objective of this study was to determine if h. felis infection alters gastric histopathology, proinflammatory cytokine expression, and secretory function and evokes a humoral immune response in cats. five specific-pathogen-free (spf) helicobacter-free cats were studied before and for 1 year after oral inoculation with h. felis (atcc 49179). four spf h. felis-uninfected cats se ... | 2000 | 10639446 |
| identification of immunodominant antigens from helicobacter pylori and evaluation of their reactivities with sera from patients with different gastroduodenal pathologies. | colonization of the gastric mucosa by helicobacter pylori is the major cause of gastroduodenal pathologies in humans. studying the outcome of the humoral immune response directed against this gastric pathogen may contribute substantially to vaccine development and to the improvement of diagnostic techniques based on serology. by using two-dimensional gel electrophoresis, 29 proteins from h. pylori g27 were identified which strongly react with sera derived from h. pylori-infected patients sufferi ... | 2000 | 10639463 |
| relationship of blood group determinants on helicobacter pylori lipopolysaccharide with host lewis phenotype and inflammatory response. | as lewis a (le(a)) and lewis b (le(b)) blood group antigens are isoforms of lewis x (le(x)) and lewis y (le(y)) and are expressed in the gastric mucosa, we evaluated whether the patterns of expression of le(x) and le(y) on helicobacter pylori lipopolysaccharides reflected those of host expression of le(a) and le(b). when 79 patients (secretors and nonsecretors) were examined for concordance between bacterial and host le expression, no association was found (chi(2) = 5.734, 3 df, p = 0.125), nor ... | 2000 | 10639467 |
| 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 ... | 2000 | 10858255 |
| isolation and characterization of a helicobacter sp. from the gastric mucosa of dolphins, lagenorhynchus acutus and delphinus delphis. | gastric ulcerations in dolphins have been reported for decades. some of these lesions were associated with parasitic infections. however, cases of nonparasitic gastric ulcers with no clearly defined etiology also have been reported in wild and captive dolphins. considerable speculation exists as to whether dolphins have helicobacter-associated gastritis and peptic ulcer disease. the stomachs of seven stranded atlantic white-sided dolphins, lagenorhynchus acutus, and 1 common dolphin, delphinus d ... | 2000 | 11055919 |
| emergence of diverse helicobacter species in the pathogenesis of gastric and enterohepatic diseases. | since helicobacter pylori was first cultivated from human gastric biopsy specimens in 1982, it has become apparent that many related species can often be found colonizing the mucosal surfaces of humans and other animals. these other helicobacter species can be broadly grouped according to whether they colonize the gastric or enterohepatic niche. gastric helicobacter species are widely distributed in mammalian hosts and are often nearly universally prevalent. in many cases they cause an inflammat ... | 2001 | 11148003 |
| evaluation of a group-specific 16s ribosomal dna-based pcr for detection of helicobacter bizzozeronii, helicobacter felis, and helicobacter salomonis in fresh and paraffin-embedded gastric biopsy specimens. | a new specific and sensitive 16s ribosomal dna-based pcr assay was developed. the assay targets a 78-bp dna fragment unique to helicobacter bizzozeronii, helicobacter felis, and helicobacter salomonis and can be used with freshly frozen and formalin-fixed paraffin-embedded gastric biopsy specimens. | 2001 | 11230459 |
| comparative genomics of helicobacter pylori: analysis of the outer membrane protein families. | the two complete genomic sequences of helicobacter pylori j99 and 26695 were used to compare the paralogous families (related genes within one genome, likely to have related function) of genes predicted to encode outer membrane proteins which were present in each strain. we identified five paralogous gene families ranging in size from 3 to 33 members; two of these families contained members specific for either h. pylori j99 or h. pylori 26695. most orthologous protein pairs (equivalent genes bet ... | 2000 | 10858232 |
| development of a selective medium for isolation of helicobacter pylori from cattle and beef samples. | helicobacter pylori has been isolated from the human stomach with media containing only minimal selective agents. however, current research on the transmission and sources of infection requires more selective media due to the higher numbers of contaminants in environmental, oral, and fecal samples. the objective of this study was to develop and evaluate detection techniques that are sufficiently selective to isolate h. pylori from potential animal and food sources. since h. pylori survives in th ... | 2000 | 10653742 |
| the neutrophil-activating protein (hp-nap) of helicobacter pylori is a protective antigen and a major virulence factor. | helicobacter pylori infection induces the appearance of inflammatory infiltrates, consisting mainly of neutrophils and monocytes, in the human gastric mucosa. a bacterial protein with neutrophil activating activity (hp-nap) has been previously identified, but its role in infection and immune response is still largely unknown. here, we show that vaccination of mice with hp-nap induces protection against h. pylori challenge, and that the majority of infected patients produce antibodies specific fo ... | 2000 | 10790422 |
| adoptive transfer of cd4+ t cells specific for subunit a of helicobacter pylori urease reduces h. pylori stomach colonization in mice in the absence of interleukin-4 (il-4)/il-13 receptor signaling. | protection in the murine model of helicobacter pylori infection may be mediated by cd4+ t cells, but the mechanism remains unclear. to better understand how protection occurs in this model, we generated and characterized h. pylori urease-specific cd4+ t cells from balb/c mice immunized with salmonella enterica serovar typhimurium expressing h. pylori urease (subunits a and b). the cd4+ t cells were found to be specific for subunit a (urea). upon antigen-specific stimulation, expression of interl ... | 2001 | 11179348 |
| immune response against a cross-reactive epitope on the heat shock protein 60 homologue of helicobacter pylori. | we previously established a monoclonal antibody (mab), designated h9, which reacts with the heat shock protein 60 (hsp60) homologue of helicobacter pylori as well as with other bacterial and human hsp60s. to determine the importance of a cross-reactive epitope on h. pylori hsp60 in h. pylori immunopathogenesis, we performed (i) mapping of an epitope on h. pylori hsp60 recognized by the h9 mab, (ii) analysis of immunoglobulin g responses of patients with or without h. pylori infection to its epit ... | 2000 | 10816497 |
| helicobacter cetorum sp. nov., a urease-positive helicobacter species isolated from dolphins and whales. | a novel helicobacter with the proposed name helicobacter cetorum, sp. nov. (type strain mit 99-5656; genbank accession number af 292378), was cultured from the main stomach of two wild, stranded atlantic white-sided dolphins (lagenorhynchus acutus) and from the feces of three captive cetaceans (a pacific white-sided dolphin [lagenorhynchus obliquidens]; an atlantic bottlenose dolphin [tursiops truncatus]; and a beluga whale [delphinapterus leucas]). the infected captive cetaceans were either sub ... | 2002 | 12454148 |
| 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 ... | 2001 | 11254638 |
| specific detection and prevalence of helicobacter heilmannii-like organisms in the human gastric mucosa by fluorescent in situ hybridization and partial 16s ribosomal dna sequencing. | gastric infection with helicobacter heilmannii (previously known as gastrospirillum hominis) is invariably linked with the presence of chronic gastritis and the risk of developing low-grade mucosa-associated lymphoid tissue lymphoma in humans. in contrast to helicobacter pylori, various h. heilmannii species colonize the stomachs of domestic animals, which might be a reservoir for transmission to humans (zoonosis). to identify the number and prevalence of different h. heilmanni types in humans, ... | 2001 | 11283079 |
| helicobacter pylori genetic diversity and risk of human disease. | | 2001 | 11285290 |
| cure of helicobacter pylori infection and resolution of gastritis by adoptive transfer of splenocytes in mice. | vaccination suppresses helicobacter pylori colonization but does not cure infection. furthermore, postvaccination gastritis, likely induced by enhanced host response to residual colonization, may exacerbate disease. the goal of this study was to determine if adoptive transfer of c57bl/6 splenocytes to c57bl/6scid/scid (severe combined immunodeficient [scid]) mice cures infection without exacerbating gastritis. h. pylori-infected and uninfected c57bl/6 mice and scid recipients of normal splenocyt ... | 2001 | 11159999 |
| helicobacter sp. flexispira bacteremia in an immunocompetent young adult. | a young immunocompetent patient was admitted for a febrile illness with malaise, arthralgias, painful leg swelling, and polyserositis. shortly prior to becoming ill, the patient had traveled to the northern african desert. the symptoms disappeared during treatment with antibiotics (doxycycline and ceftriaxone) but recurred twice after stopping therapy. a motile gram-negative fusiform rod was isolated from a blood culture taken on the first admission. analysis of the 16s rrna gene of the blood cu ... | 2001 | 11325980 |
| comh, a novel gene essential for natural transformation of helicobacter pylori. | helicobacter pylori is naturally competent for transformation, but the dna uptake system of this bacterium is only partially characterized, and nothing is known about the regulation of competence in h. pylori. to identify other components involved in transformation or competence regulation in this species, we screened a mutant library for competence-deficient mutants. this resulted in the identification of a novel, helicobacter-specific competence gene (comh) whose function is essential for tran ... | 2000 | 10869072 |
| acid-induced gene expression in helicobacter pylori: study in genomic scale by microarray. | to understand the rna expression in response to acid stress of helicobacter pylori in genomic scale, a microarray membrane containing 1,534 open reading frames (orfs) from strain 26695 was used. total rnas of h. pylori under growth conditions of ph 7.2 and 5.5 were extracted, reverse transcribed into cdna, and labeled with biotin. each microarray membrane was hybridized with cdna probe from the same strain under two different ph conditions and developed by a catalyzed reporter deposition method. ... | 2001 | 11179343 |
| differential gene expression from two transcriptional units in the cag pathogenicity island of helicobacter pylori. | infection with helicobacter pylori strains containing the cag pathogenicity island (cag pai) is strongly correlated with the development of severe gastric disease, including gastric and duodenal ulceration, mucosa-associated lymphoid tissue lymphoma, and gastric carcinoma. although in vitro studies have demonstrated that the expression of genes within the cag pai leads to the activation of a strong host inflammatory response, the functions of most cag gene products and how they work in concert t ... | 2001 | 11401955 |
| helicobacter pylori pore-forming cytolysin orthologue tlya possesses in vitro hemolytic activity and has a role in colonization of the gastric mucosa. | hemolysins have been found to possess a variety of functions in bacteria, including a role in virulence. helicobacter pylori demonstrates hemolytic activity when cultured on unlysed blood agar plates which is increased under iron-limiting conditions. however, the role of an h. pylori hemolysin in virulence is unclear. scrutiny of the h. pylori 26695 genome sequence suggests the presence of at least two distinct hemolysins, hp1086 and hp1490, in this strain. previous studies have shown that the i ... | 2001 | 11179345 |
| sequence and antigenic variability of the helicobacter mustelae surface ring protein hsr. | we have identified an array of more than 500 repetitive sequences flanking the hsr gene, which encodes the major surface protein of the ferret pathogen helicobacter mustelae. the repeats show identity exclusively to the amino-terminal half of hsr. analysis of hsr from three strains indicated variability of exposed epitopes. characterization of an hsr mutant showed that hsr is not an adhesin. | 2001 | 11292773 |
| helicobacter typhlonius sp. nov., a novel murine urease-negative helicobacter species. | over the past decade, several helicobacter species have been isolated from rodents. with the advent of pcr for the diagnosis of infectious agents, it has become clear that several previously uncharacterized helicobacter species also colonize rodents. in this report, we describe a novel urease-negative helicobacter, helicobacter typhlonius sp. nov., which was isolated from colonies of laboratory mice independently by two laboratories. infection of immunodeficient mice by this bacterium resulted i ... | 2001 | 11682508 |
| bioinformatics analysis of the locus for enterocyte effacement provides novel insights into type-iii secretion. | like many other pathogens, enterohaemorrhagic and enteropathogenic strains of escherichia coli employ a type-iii secretion system to translocate bacterial effector proteins into host cells, where they then disrupt a range of cellular functions. this system is encoded by the locus for enterocyte effacement. many of the genes within this locus have been assigned names and functions through homology with the better characterised ysc-yop system from yersinia spp. however, the functions and homologie ... | 2005 | 15757514 |
| coinfection of enteric helicobacter spp. and campylobacter spp. in cats. | during a 6-year period, 64 of 227 commercially reared cats had microaerobic bacteria isolated from their feces. all the isolates were initially identified as campylobacter-like organisms based on biochemical and phenotypic characteristics. dna extractions from 51 of these isolates were subjected to pcr using primers specific for helicobacter spp. and campylobacter spp. of the isolates, 92% (47 of 51 isolates) were positive for campylobacter spp., 41% (21 of 51 isolates) were positive for helicob ... | 2001 | 11376052 |
| 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 ... | 2001 | 11418100 |
| local ph elevation mediated by the intrabacterial urease of helicobacter pylori cocultured with gastric cells. | helicobacter pylori resists gastric acidity by modulating the proton-gated urea channel urei, allowing for ph(out)-dependent regulation of urea access to intrabacterial urease. we employed ph- and ca(2+)-sensitive fluorescent dyes and confocal microscopy to determine the location, rate, and magnitude of ph changes in an h. pylori-ags cell coculture model, comparing wild-type bacteria with nonpolar urei-deletion strains (urei-ve). addition of urea at ph 5.5 to the coculture resulted first in elev ... | 2000 | 10930437 |
| catalase, a specific antigen in the feces of human subjects infected with helicobacter pylori. | recently, we reported the production of three new monoclonal antibodies with high specificity for a helicobacter pylori antigen suitable for diagnosis of h. pylori infection. the aim of the present study was to identify the antigen recognized by these monoclonal antibodies concerning both h. pylori and the feces of human subjects infected with h. pylori. the cellular antigen was purified from an h. pylori cell extract by immunoaffinity column chromatography with the monoclonal antibody as a liga ... | 2002 | 12093673 |
| role of flic and flid flagellar proteins of clostridium difficile in adherence and gut colonization. | in vitro and in vivo adhesive properties of flagella and recombinant flagellin flic and flagellar cap flid proteins of clostridium difficile were analyzed. flic, flid, and crude flagella adhered in vitro to axenic mouse cecal mucus. radiolabeled cultured cells bound to a high degree to flid and weakly to flagella deposited on a membrane. the tissue association in the mouse cecum of a nonflagellated strain was 10-fold lower than that of a flagellated strain belonging to the same serogroup, confir ... | 2001 | 11705981 |
| production and application of new monoclonal antibodies specific for a fecal helicobacter pylori antigen. | the aim of the present study was to establish monoclonal antibodies that could be used to produce a diagnostic test composed of one kind of monoclonal antibody recognizing a fecal helicobacter pylori antigen. the need to develop such a test arose from disadvantages of the diagnostic test that uses a polyclonal antibody or plural kinds of monoclonal antibodies, such as the lower specificity for h. pylori antigen and the difficulty of reproduction with consistent quality. mice were immunized with ... | 2002 | 11777832 |
| in vivo killing of porphyromonas gingivalis by toluidine blue-mediated photosensitization in an animal model. | porphyromonas gingivalis is one of the major causative organisms of periodontitis and has been shown to be susceptible to toluidine blue-mediated photosensitization in vitro. the aims of the present study were to determine whether this technique could be used to kill the organism in the oral cavities of rats and whether this would result in a reduction in the alveolar bone loss characteristic of periodontitis. the maxillary molars of rats were inoculated with p. gingivalis and exposed to up to 4 ... | 2003 | 12604524 |
| expression and characterization of a histidine-rich protein, hpn: potential for ni2+ storage in helicobacter pylori. | hpn is a small cytoplasmic protein found in helicobacter pylori, which binds ni2+ ions with moderate affinity. consisting of 60 amino acids, the protein is rich in histidine (28 residues, 46.7%), as well as glutamate, glycine and serine residues (in total 31.7%), and contains short repeating motifs. in the present study, we report the detailed biophysical characterization of the multimeric status and ni2+-binding properties of purified recombinant hpn under physiologically relevant conditions. t ... | 2006 | 16164421 |
| cloning and characterization of a helicobacter bizzozeronii urease gene cluster. | the urease gene cluster from helicobacter bizzozeronii was cloned and sequenced. a genomic library was constructed in a lambda-zapii vector using tsp5091-digested h. bizzozeronii chromosomal dna. four overlapping recombinant bacteriophages carrying the h. bizzozeronii urease genes were identified by using a fragment of h. bizzozeronii ureb as a probe. sequence analysis of two clones (phb1 and phb3) revealed seven open reading frames encoding proteins with predicted masses of 26.5, 60.3, 21.7, 19 ... | 2002 | 12652903 |
| selection for urease activity during helicobacter pylori infection of rhesus macaques (macaca mulatta). | helicobacter pylori strain j166 recovered from experimentally inoculated rhesus monkeys had up to a 250-fold-increased urease activity over that before inoculation. this was found to result from the selection of urease positive j166 clones from a heterogeneous inoculum, which was predominantly urease negative due to a 1-bp insertion in the urea gene. these results confirm the importance of urease for h. pylori colonization. strain j166 is particularly well adapted to the rhesus monkey, since it ... | 2001 | 11292788 |
| gamma-glutamyltransferase is a helicobacter pylori virulence factor but is not essential for colonization. | the contribution of glutamyl transpeptidase (ggt) (gamma-glutamyltransferase [ec 2. 3. 2. 2]) to helicobacter pylori virulence was investigated in piglets and mice using ggt-deficient isogenic strains. all animals became colonized. however, the bacterial load was significantly lower for mutant bacteria than for parent strains. these results suggest that ggt activity provides an advantage to h. pylori in colonization. | 2001 | 11349094 |
| expression and characterization of a histidine-rich protein, hpn: potential for ni2+ storage in helicobacter pylori. | hpn is a small cytoplasmic protein found in helicobacter pylori, which binds ni2+ ions with moderate affinity. consisting of 60 amino acids, the protein is rich in histidine (28 residues, 46.7%), as well as glutamate, glycine and serine residues (in total 31.7%), and contains short repeating motifs. in the present study, we report the detailed biophysical characterization of the multimeric status and ni2+-binding properties of purified recombinant hpn under physiologically relevant conditions. t ... | 2006 | 16164421 |
| observation of helicobacter-like organisms in gastric mucosa of grey foxes (urocyon cinereoargenteus) and bobcats (lynx rufus). | archival specimens of gastric mucosa of 10 raccoons (procyon lotor), 9 porcupines (erethizon dorsatum), 6 grey foxes (urocyon cinereoargenteus), 6 bobcats (lynx rufus), 4 skunks (mephitis mephitis), and 3 black bears (ursus americanus) were microscopically examined for evidence of helicobacter-like organisms. such organisms were seen in the specimens from the grey foxes and bobcats only. histochemical stains (modified steiner and carbol fuchsin methods) revealed long spiral organisms within lumi ... | 2004 | 15188962 |
| helicobacter winghamensis sp. nov., a novel helicobacter sp. isolated from patients with gastroenteritis. | from 1997 to 1999 seven isolates of campylobacter-like organisms from five patients that were exhibiting symptoms of gastroenteritis, including fever, stomach malaise, and diarrhea, were investigated. the organisms were isolated from stool samples and found to exhibit a diverse colony morphology; hence multiple isolates were submitted from one of the patients. all isolates were found to be identical. the organisms were catalase, urease, alkaline phosphatase, and nitrate negative but oxidase and ... | 2001 | 11427547 |
| specific detection of arcobacter and campylobacter strains in water and sewage by pcr and fluorescent in situ hybridization. | the aim of this study was to evaluate pcr and fluorescent in situ hybridization (fish) techniques for detecting arcobacter and campylobacter strains in river water and wastewater samples. both 16s and 23s rrna sequence data were used to design specific primers and oligonucleotide probes for pcr and fish analyses, respectively. in order to assess the suitability of the methods, the assays were performed on naturally and artificially contaminated samples and compared with the isolation of cells on ... | 2003 | 12571045 |
| enteropathogenic escherichia coli virulence factor bundle-forming pilus has a binding specificity for phosphatidylethanolamine. | the bundle-forming pilus (bfp) of enteropathogenic escherichia coli (epec), an established virulence factor encoded on the epec adherence factor (eaf) plasmid, has been implicated in the formation of bacterial autoaggregates and in the localized adherence of epec to cultured epithelial cells. while understanding of the pathogenic mechanism of this organism is rapidly improving, a receptor ligand for bfp has not yet been identified. we now report, using both solid-phase and liposome binding assay ... | 2001 | 11598024 |
| helicobacter pylori growth and urease detection in the chemically defined medium ham's f-12 nutrient mixture. | obstacles continue to hinder in vitro studies of the gastric human pathogen helicobacter pylori, including difficulty culturing the organism in the absence of serum or blood, rapid loss of viability following exponential growth due to autolysis, and the necessity for using high starting inocula. we demonstrate that h. pylori grows in the chemically defined broth medium ham's f-12 nutrient mixture (f-12) in the absence of fetal bovine serum (fbs); this represents a breakthrough for studies in whi ... | 2001 | 11682496 |
| binding of actinobacillus pleuropneumoniae to phosphatidylethanolamine. | the gram-negative bacterium actinobacillus pleuropneumoniae is the causative agent of porcine fibrinohemorrhagic necrotizing pleuropneumonia, a disease that causes important economic losses to the swine industry worldwide. in general, the initial step of bacterial colonization is attachment to host cells. the purpose of the present study was to evaluate the binding of a. pleuropneumoniae serotype 1 to phospholipids, which are the major constituents of biological membranes. phospholipids serve as ... | 2003 | 12874346 |
| the ferret gastrointestinal tract and helicobacter mustelae infection. | | 2005 | 15817250 |
| isolation of helicobacter mustelae from ferrets in new zealand. | the bacterial genus helicobacter contains over 20 species, including the human gastric pathogen h. pylori, and the mustelid-specific h. mustelae. a previous study in this country failed to isolate h. mustelae from a captive breeding colony of ferrets. we sought to confirm whether or not h. mustelae was present in this country. | 2000 | 16032121 |
| detection and isolation of helicobacter mustelae from stoats in new zealand. | to determine the incidence of helicobacter mustelae in stoats (mustela erminea) in new zealand. | 2003 | 16032314 |
| in vivo behavior of a helicobacter pylori ss1 nixa mutant with reduced urease activity. | helicobacter pylori mutants devoid of urease activity fail to colonize the gastric mucosa of mice; however, the effect of decreased levels of urease on colonization has not been examined. the nixa gene, required for full urease activity, encodes a cytoplasmic membrane nickel transporter that imports nickel ions and leads to incorporation of nickel ions into apourease. a nixa mutant of the sydney strain of h. pylori (ss1) was constructed by disruption of the nixa gene with a kanamycin resistance ... | 2002 | 11796600 |
| species differentiation and identification in the genus of helicobacter. | | 1999 | 11819372 |
| glycoconjugate binding of gastric and enterohepatic helicobacter spp. | helicobacter pylori is able to utilize several lectin-like, protein-carbohydrate interactions for binding to mucins, cell surfaces, and extracellular matrix proteins. as determined by hemagglutination assays and binding of radiolabeled bacteria to glycosphingolipids on thin-layer chromatograms, strains of gastric helicobacters and enterohepatic helicobacters, including helicobacter canis, helicobacter hepaticus, and helicobacter bilis, also demonstrated evidence for the presence of lectin-hemagg ... | 2003 | 12704182 |
| detection of helicobacter pylori in gastric mucosa of patients with gastroduodenal diseases by pcr-restriction analysis using the rna polymerase gene (rpob). | a novel pcr restriction analysis method using the rna polymerase beta-subunit- coding gene (rpob) was employed to both detect and identify helicobacter pylori in biopsy specimens and culture isolates. the rpob dnas (458 bp) were specifically amplified by pcr with the helicobacter-specific primers (hf and hr). based on the determined rpob sequences of the culture isolates, an h. pylori-specific restriction site, tru9i, was found. h. pylori can be identified by observing two discernible dna fragme ... | 2003 | 12843100 |
| cloning, expression, and catalytic activity of helicobacter hepaticus urease. | helicobacter hepaticus causes disease in the liver and lower intestinal tract of mice. it is strongly urease positive, although it does not live in an acidic environment. the h. hepaticus urease gene cluster was expressed in escherichia coli with and without coexpression of the helicobacter pylori nickel transporter nixa. as for h. pylori, it was difficult to obtain enzymatic activity from recombinant h. hepaticus urease; special conditions including nicl2 supplementation were required. the h. h ... | 2001 | 11500473 |
| failure of surface ring mutant strains of helicobacter mustelae to persistently infect the ferret stomach. | helicobacter mustelae, the gastric pathogen of ferrets, produces an array of surface ring structures which have not been described for any other member of the genus helicobacter, including h. pylori. the unique ring structures are composed of a protein named hsr. to investigate whether the hsr rings are important for colonization of the ferret stomach, ferrets specific pathogen free for h. mustelae were inoculated with an hsr-deficient mutant strain or the wild-type h. mustelae strain. quantitat ... | 2003 | 12704104 |
| a novel action of the proton pump inhibitor rabeprazole and its thioether derivative against the motility of helicobacter pylori. | the motility of helicobacter pylori was maximum at 37 degrees c and at ph 6. a newly developed proton pump inhibitor, rabeprazole (rpz), and its thioether derivative (rpz-th) markedly inhibited the motility of h. pylori. the concentrations of the drug necessary to inhibit 50% of the motility were 0.25, 16, 16, and >64 microgram/ml for rpz-th, rpz, lansoprazole, and omeprazole, respectively. no such inhibitory effects were observed with h(2) blockers or anti-h. pylori agents. the motilities of ca ... | 2000 | 11036024 |
| iron-responsive repression of urease expression in helicobacter hepaticus is mediated by the transcriptional regulator fur. | persistent colonization of mucosal surfaces by bacteria in the mammalian host requires concerted expression of colonization factors, depending on the environmental conditions. helicobacter hepaticus is a urease-positive pathogen that colonizes the intestinal and hepatobiliary tracts of rodents. here it is reported that urease expression of h. hepaticus is iron repressed by the transcriptional regulator fur. iron restriction of growth medium resulted in a doubling of urease activity in wild-type ... | 2007 | 17101656 |
| evasion of toll-like receptor 5 by flagellated bacteria. | toll-like receptor 5 (tlr5) recognizes an evolutionarily conserved site on bacterial flagellin that is required for flagellar filament assembly and motility. the alpha and epsilon proteobacteria, including the important human pathogens campylobacter jejuni, helicobacter pylori, and bartonella bacilliformis, require flagellar motility to efficiently infect mammalian hosts. in this study, we demonstrate that these bacteria make flagellin molecules that are not recognized by tlr5. we map the site r ... | 2005 | 15956202 |
| iron-responsive repression of urease expression in helicobacter hepaticus is mediated by the transcriptional regulator fur. | persistent colonization of mucosal surfaces by bacteria in the mammalian host requires concerted expression of colonization factors, depending on the environmental conditions. helicobacter hepaticus is a urease-positive pathogen that colonizes the intestinal and hepatobiliary tracts of rodents. here it is reported that urease expression of h. hepaticus is iron repressed by the transcriptional regulator fur. iron restriction of growth medium resulted in a doubling of urease activity in wild-type ... | 2007 | 17101656 |
| alterations in gastric mucin synthesis by helicobacter pylori. | | 2000 | 11819633 |
| helicobacter pylori-infected animal models are extremely suitable for the investigation of gastric carcinogenesis. | although various animal models have been developed to clarify gastric carcinogenesis, apparent mechanism of gastric cancer was not clarified in recent years. since the recognition of the pathogenicity of helicobacter pylori (h pylori), several animal models with h pylori infection have been developed to confirm the association between h pylori and gastric cancer. nonhuman primate and rodent models were suitable for this study. japanese monkey model revealed atrophic gastritis and p53 mutation af ... | 2005 | 16437649 |
| multiplex pcr assay for differentiation of helicobacter felis, h. bizzozeronii, and h. salomonis. | helicobacter felis, helicobacter bizzozeronii, and helicobacter salomonis are frequently found in the gastric mucous membrane of dogs and cats. these large spiral organisms are phylogenetically highly related to each other. their fastidious nature makes it difficult to cultivate them in vitro, hampering traditional identification methods. we describe here a multiplex pcr test based on the trna intergenic spacers and on the urease gene, combined with capillary electrophoresis, that allows discrim ... | 2004 | 15004062 |
| 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 ... | 2005 | 16192433 |
| intervening sequence acquired by lateral gene transfer in tropheryma whipplei results in 23s rrna fragmentation. | completion of tropheryma whipplei genome sequencing may provide insights into the evolution of the molecular mechanisms underlying the pathogenicity of this microorganism. the first postgenomic application was the successful design of a comprehensive culture medium that allows axenic growth of this bacterium, which is particularly recalcitrant to cultivation. this achievement in turn permitted analysis of t. whipplei rna without contaminating eukaryotic nucleic acids. to obtain high-quality rna, ... | 2005 | 16269699 |
| polar flagellum biogenesis in aeromonas hydrophila. | mesophilic aeromonas spp. constitutively express a single polar flagellum that helps the bacteria move to more favorable environments and is an important virulence and colonization factor. certain strains can also produce multiple lateral flagella in semisolid media or over surfaces. we have previously reported 16 genes (flgn to flgl) that constitute region 1 of the aeromonas hydrophila ah-3 polar flagellum biogenesis gene clusters. we identified 39 new polar flagellum genes distributed in four ... | 2006 | 16385045 |
| comparative chemical and biological characterization of the lipopolysaccharides of gastric and enterohepatic helicobacters. | the lipopolysaccharide of helicobacter pylori plays an important role in colonization and pathogenicity. the present study sought to compare structural and biological features of lipopolysaccharides from gastric and enterohepatic helicobacter spp. not previously characterized. | 2004 | 15270745 |
| real-time pcr screening for 16s rrna mutations associated with resistance to tetracycline in helicobacter pylori. | the effectiveness of recommended first-line therapies for helicobacter pylori infections is decreasing due to the occurrence of resistance to metronidazole and/or clarithromycin. quadruple therapies, which include tetracycline and a bismuth salt, are useful alternative regimens. however, resistance to tetracycline, mainly caused by mutations in the 16s rrna genes (rrna and rrnb) affecting nucleotides 926 to 928, are already emerging and can impair the efficacies of such second-line regimens. her ... | 2005 | 16048919 |
| discordant 16s and 23s rrna gene phylogenies for the genus helicobacter: implications for phylogenetic inference and systematics. | analysis of 16s rrna gene sequences has become the primary method for determining prokaryotic phylogeny. phylogeny is currently the basis for prokaryotic systematics. therefore, the validity of 16s rrna gene-based phylogenetic analyses is of fundamental importance for prokaryotic systematics. discrepancies between 16s rrna gene analyses and dna-dna hybridization and phenotypic analyses have been noted in the genus helicobacter. to clarify these discrepancies, we sequenced the 23s rrna genes for ... | 2005 | 16109952 |
| nutritional requirements and antibiotic resistance patterns of helicobacter species in chemically defined media. | the growth of the gastric pathogen helicobacter pylori in the absence of serum remains challenging, and nutritional requirements have only partially been defined, while almost nothing is known about nutritional requirements of other helicobacter spp. although previous data showed that h. pylori grows in the chemically defined medium f-12, but not in other tissue culture media examined, the specific components responsible for growth were not entirely understood. here we describe the optimization ... | 2006 | 16672389 |
| analysis of the lateral flagellar gene system of aeromonas hydrophila ah-3. | mesophilic aeromonas strains express a polar flagellum in all culture conditions, and certain strains produce lateral flagella on semisolid media or on surfaces. although aeromonas lateral flagella have been described as a colonization factor, little is known about their organization and expression. here we characterized the complete lateral flagellar gene cluster of aeromonas hydrophila ah-3 containing 38 genes, 9 of which (lafa-u) have been reported previously. among the flgll and lafa structu ... | 2006 | 16428388 |
| the helicobacter pylori chemotaxis receptor tlpb (hp0103) is required for ph taxis and for colonization of the gastric mucosa. | the location of helicobacter pylori in the gastric mucosa of mammals is defined by natural ph gradients within the gastric mucus, which are more alkaline proximal to the mucosal epithelial cells and more acidic toward the lumen. we have used a microscope slide-based ph gradient assay and video data collection system to document ph-tactic behavior. in response to hydrochloric acid (hcl), h. pylori changes its swimming pattern from straight-line random swimming to arcing or circular patterns that ... | 2006 | 16547053 |
| the gaggle: an open-source software system for integrating bioinformatics software and data sources. | systems biologists work with many kinds of data, from many different sources, using a variety of software tools. each of these tools typically excels at one type of analysis, such as of microarrays, of metabolic networks and of predicted protein structure. a crucial challenge is to combine the capabilities of these (and other forthcoming) data resources and tools to create a data exploration and analysis environment that does justice to the variety and complexity of systems biology data sets. a ... | 2006 | 16569235 |
| comparative genomics and proteomics of helicobacter mustelae, an ulcerogenic and carcinogenic gastric pathogen. | helicobacter mustelae causes gastritis, ulcers and gastric cancer in ferrets and other mustelids. h. mustelae remains the only helicobacter other than h. pylori that causes gastric ulceration and cancer in its natural host. to improve understanding of h. mustelae pathogenesis, and the ulcerogenic and carcinogenic potential of helicobacters in general, we sequenced the h. mustelae genome, and identified 425 expressed proteins in the envelope and cytosolic proteome. | 2010 | 20219135 |
| pathogenesis of helicobacter pylori infection. | helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. unless treated, colonization usually persists lifelong. h. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-assoc ... | 2006 | 16847081 |
| the complete genome sequence and analysis of the epsilonproteobacterium arcobacter butzleri. | arcobacter butzleri is a member of the epsilon subdivision of the proteobacteria and a close taxonomic relative of established pathogens, such as campylobacter jejuni and helicobacter pylori. here we present the complete genome sequence of the human clinical isolate, a. butzleri strain rm4018. | 2007 | 18159241 |