identification of campylobacter jejuni promoter sequences.a promoterless lacz shuttle vector, which allowed screening of promoters by beta-galactosidase activity in campylobacter jejuni and escherichia coli, was developed. chromosomal dna fragments from c. jejuni were cloned into this vector; 125 of 1,824 clones displayed promoter activity in c. jejuni. eleven clones with strong promoter activity in c. jejuni were further characterized. their nucleotide sequences were determined, and the transcriptional start sites of the putative promoters in c. jejun ...19989457862
effect of low temperatures on growth, structure, and metabolism of campylobacter coli sp10.the effect of low temperatures on the survival, structure, and metabolism of campylobacter coli sp10, a virulent strain, was investigated. c. coli became nonculturable rapidly at 20 and 10 degree c and slightly later at 4 degrees c. incubation in a microaerobic atmosphere improved survival, but after day 8, campylobacters were detectable by direct-count procedures only. the increase in the number of coccoid cells was most pronounced at 37 degrees c but also was noticeable at 20 and 10 degrees c. ...19989464397
extended survival and persistence of campylobacter spp. in water and aquatic biofilms and their detection by immunofluorescent-antibody and -rrna water microcosm experiments, the survival times of campylobacter isolates differed by up to twofold, as determined by culturing; this difference increased to fourfold when particular combinations of temperature and oxygenation were used. the mean survival times were much longer at 4 and 10 degrees c (202 and 176 h, respectively) than at 22 and 37 degrees c (43 and 22 h, respectively). the influence of anaerobiosis on survival time was less dramatic and differed considerably between isolates. ...19989464415
serotyping scheme for campylobacter jejuni and campylobacter coli based on direct agglutination of heat-stable antigens.campylobacter is now the most frequently reported cause of gastrointestinal disease in england and wales, yet few isolates are characterized beyond the genus level. the majority of isolates are campylobacter jejuni (90%), with most of the remainder being campylobacter coli. we describe an adaptation of the penner serotyping scheme in which passive hemagglutination has been replaced by detection of heat-stable antigens by direct bacterial agglutination; absorbed antisera are used where appropriat ...19989466737
trna(arg) (fimu) and expression of sef14 and sef21 in salmonella enteritidis.a tn10 insertion affecting sef14 fimbrial synthesis in salmonella enteritidis was located 13 bp upstream of a gene designated fimu. the 77-bp dna sequence of fimu from s. enteritidis was identical to that of fimu encoding trna(arg) (ucu) from salmonella typhimurium and 96% identical to that of the escherichia coli argu homolog. furthermore, the open reading frame adjacent to and overlapping the 3' end of fimu was similar to the prophage dlp12 integrase gene. the fimu-encoded transcript comigrate ...19989473037
mutation in the peb1a locus of campylobacter jejuni reduces interactions with epithelial cells and intestinal colonization of mice.campylobacter jejuni is one of the leading causes of bacterial diarrhea throughout the world. we previously found that peb1 is a homolog of cluster 3 binding proteins of bacterial abc transporters and that a c. jejuni adhesin, cell-binding factor 1 (cbf1), if not identical to, contains peb1. a single protein migrating at approximately 27 to 28 kda was recognized by anti-cbf1 and anti-peb1. to determine the role that the operon encoding peb1 plays in c. jejuni adherence, peb1a, the gene encoding ...19989488379
the pseudomonas aeruginosa flagellar cap protein, flid, is responsible for mucin adhesion.mucin-specific adhesion of pseudomonas aeruginosa plays an important role in the initial colonization of this organism in the airways of cystic fibrosis patients. we report here that the flagellar cap protein, flid, participates in this adhesion process. a polar chromosomal insertional mutation in the p. aeruginosa flid gene made this organism nonadhesive to mucin in an in vitro mucin adhesion assay. the adhesive phenotype was restored by providing the flid gene alone on a multicopy plasmid, sug ...19989488388
variation in flagellin genes and proteins of burkholderia cepacia.the majority of isolates of burkholderia cepacia, an important opportunistic pathogen associated with cystic fibrosis, can be classified into two types on the basis of flagellin protein size. electron microscopic analysis indicates that the flagella of strains with the larger flagellin type (type i) are wider in diameter. flagellin genes representative of both types were cloned and sequenced to design oligonucleotide primers for pcr amplification of the central variable domain of b. cepacia flag ...19989495748
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 ...19989495749
transcription of ppk from acinetobacter sp. strain adp1, encoding a putative polyphosphate kinase, is induced by phosphate starvation.polyphosphate kinase (ppk) catalyzes the formation of polyphosphate from atp. we cloned the ppk gene (2,073 bp) from acinetobacter sp. strain adp1; this gene encodes a putative polypeptide of 78.6 kda with extensive homology to polyphosphate kinase from escherichia coli and other bacteria. chromosomal disruption of ppk by inserting a transcriptionally fused lacz does not affect growth under conditions of phosphate limitation or excess. beta-galactosidase activity expressed from the single-copy p ...19989501429
enrichment medium for isolation of campylobacter jejuni-campylobacter coli.a kaseini-broth enrichment medium (kbem) for the isolation improvement of campylobacter jejuni-campylobacter coli from stool samples is described. isolation of campylobacters from stool specimens by direct inoculation onto solid selective medium was compared with isolation after twenty-four hours enrichment at 37 degrees c in kbem, followed by subculture onto the same solid selective medium. of 156 examined stool samples from diarrhoeal children positive results were obtained from 17 patients al ...19959524671
ribosomal rna gene restriction fragment diversity amongst penner serotypes of campylobacter jejuni and campylobacter coli.diversity based on ribosomal rna gene-restriction endonuclease digest patterns was detected amongst forty-seven strains of campylobacter made up of 38 strains of campylobacter jejuni and 9 strains of campylobacter coli. restriction digests of chromosomal dna prepared by treating with hae iii were probed with an oligonucleotide specific for campylobacter 16s ribosomal rna genes. seventeen distinct hybridization patterns, each indicating the presence of 2-4 copies of the 16s rrna gene are encoded ...19989528123
a cyanobacterium lacking iron superoxide dismutase is sensitized to oxidative stress induced with methyl viologen but is not sensitized to oxidative stress induced with norflurazona strain of synechococcus sp. strain pcc 7942 with no functional fe superoxide dismutase (sod), designated sodb-, was characterized by its growth rate, photosynthetic pigments, and cyclic photosynthetic electron transport activity when treated with methyl viologen or norflurazon (nf). in their unstressed conditions, both the sodb- and wild-type strains had similar chlorophyll and carotenoid contents and catalase activity, but the wild type had a faster growth rate and higher cyclic electron tran ...19989536078
a rapid pcr-based dna test for enterotoxic bacillus cereus.the occurrence of dna sequences encoding the hemolysin hbla complex and bacillus cereus enterotoxin bcet, which have recently been confirmed as enterotoxins, was studied in bacillus spp. to amplify these dna sequences, pcr primer systems for the b component of hbla and for bcet dna sequences were developed. the results from the amplification of hbla sequences correlated well with results obtained with the b. cereus enterotoxin (diarrheal type) test kit (rpla kit), but not with the results of the ...19989572928
evidence of genomic instability in campylobacter jejuni isolated from poultry.poultry isolates of campylobacter jejuni derived from a survey of meat processing batches were genotyped by pulsed-field gel electrophoresis (pfge) of chromosomal dna to establish the clonal relationships between single-colony isolates. in the majority of batches studied, one or two genotype patterns predominated. however, in one batch (batch a), 21 single-colony isolates gave 14 different pfge genotypes. the banding patterns obtained with smai were sufficiently different to distinguish between ...19989572956
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, which catalyzes the reaction: nh3 + glutamate + atp-->glutamine + adp + pi. we hypothesized that glutamine synthetase plays an unusually critical role in nitrogen assimilation ...19989573059
campylobacter jejuni cytolethal distending toxin causes a g2-phase cell cycle block.cytolethal distending toxin (cdt) from the diarrheagenic bacterium campylobacter jejuni was shown to cause a rapid and specific cell cycle arrest in hela and caco-2 cells. within 24 h of treatment, cdt caused hela cells to arrest with a 4n dna content, indicative of cells in g2 or early m phase. immunofluorescence studies indicated that the arrested cells had not entered m phase, since no evidence of tubulin reorganization or chromatin condensation was visible. cdt treatment was also shown to ca ...19989573072
characterization of chemotactic responses and flagella of hyphomicrobium strain w1-1b.motile swarmer cells of hyphomicrobium strain w1-1b displayed positive chemotactic responses toward methylamine, dimethylamine, and trimethylamine but did not display significant chemotactic responses towards methanol and arginine. electron micrographs of negatively stained intact flagellar filaments indicated a novel striated surface pattern. the flagella were composed of two proteins of 39 and 41 kda. neither protein was a glycoprotein as determined by schiff's staining and by enzyme immunoass ...19989603896
typing of human campylobacter jejuni isolates in finland by pulsed-field gel electrophoresis.a total of 69 pulsed-field gel electrophoresis (pfge) types were identified among 176 campylobacter jejuni isolates from finnish patients. in two geographic areas studied, five predominant pfge types comprised over 40% of the isolates. one-third of the isolates had unique pfge types. in small outbreaks, identical pfge patterns were demonstrated, indicating a common source of infection.19989620423
cloning and comparison of flic genes and identification of glycosylation in the flagellin of pseudomonas aeruginosa a-type strains.pseudomonas aeruginosa a-type strains produce flagellin proteins which vary in molecular weight between strains. to compare the properties of a-type flagellins, the flagellin genes of several pseudomonas aeruginosa a-type strains, as determined by interaction with specific anti-a monoclonal antibody, were cloned and sequenced. pcr amplification of the a-type flagellin gene fragments from five strains each yielded a 1.02-kb product, indicating that the gene size is not likely to be responsible fo ...19989620973
an outbreak of infectious hepatitis in commercially reared ostriches associated with campylobacter coli and campylobacter jejuni.a disease causing high morbidity and mortality was observed in young ostriches from six properties in southeast queensland, australia. the disease affected birds from 2-8 weeks of age and was characterised clinically by bright-green urates and pathologically by severe necrotic hepatitis. the liver lesions resembled those of vibrionic hepatitis in other avian species. campylobacter coli was isolated from the livers of affected ostriches from five of the six properties. campylobacter jejuni subsp. ...19989631530
heterogeneity in levels of vacuolating cytotoxin gene (vaca) transcription among helicobacter pylori strains.broth culture supernatants from tox+ helicobacter pylori strains induce vacuolation of hela cells in vitro and contain vaca in concentrations that are higher than those found in supernatants from tox- h. pylori strains. to investigate the basis for this phenomenon, we analyzed the transcription of the vacuolating cytotoxin gene (vaca) in eight tox+ strains (each with a type s1/m1 vaca genotype) and nine tox- strains (each with a type s2/m2 vaca genotype). most of the tox+ and tox- strains tested ...19989632570
isolation and molecular analysis of colonising and non-colonising strains of campylobacter jejuni and campylobacter coli following experimental infection of young chickens.fourteen-day-old chickens were inoculated with selected campylobacter coli and c. jejuni strains. c. jejuni strains were of two subgroups based on a polymorphism detected using a dna probe and represented the profiles typical for the majority of strains of either chicken or human origin. all c. coli strains previously isolated from humans colonised chickens, whereas from 4/7 c. jejuni strains of human origin, failed to colonise. of 12 campylobacter strains of chicken origin, 10 established a per ...19989646454
epidemiological typing of campylobacter isolates from meat processing plants by pulsed-field gel electrophoresis, fatty acid profile typing, serotyping, and biotyping.campylobacter spp. are a leading cause of bacterial gastroenteritis. foods of animal origin, particularly under-cooked poultry, are common sources of campylobacter species associated with disease in humans. a collection of 110 campylobacter jejuni and 31 c. coli human and environmental isolates from different ontario, canada, abattoirs were analyzed by pulsed-field gel electrophoresis, fatty acid profile typing, and biotyping. previously collected serotyping data for the same isolates were also ...19989647797
microtiter assay for detecting campylobacter spp. and helicobacter pylori with surface gangliosides which bind cholera toxin.campylobacter jejuni with gm1 ganglioside in the core of its lipopolysaccharide has been associated with guillain-barré syndrome. since this epitope may be of considerable pathophysiologic importance and since this ganglioside binds cholera toxin, a rapid screening assay to detect bacteria that bind cholera toxin as an indication of gm1 on their surfaces was developed. in the assay, bacterial lawns were grown on agar plates, harvested with phosphate-buffered saline, boiled, and incubated with a ...19989650959
the central, surface-exposed region of the flagellar hook protein flge of campylobacter jejuni shows hypervariability among 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 ...19989658019
antimicrobial susceptibility testing of 59 strains of campylobacter fetus subsp. fetus.the susceptibilities of 59 campylobacter fetus subsp. fetus isolates to eight antibiotics were studied by the agar dilution, e-test, and disk diffusion methods. none of the isolates were beta-lactamase producers. all were susceptible to ampicillin, gentamicin, imipenem, and meropenem as determined by the three methods, with mics at which 90% of the isolates are inhibited (mic90s) (determined by agar dilution) of 2, 1, < or = 0.06, and 0.12 microgram/ml, respectively. twenty-seven percent of the ...19989661033
campylobacter upsaliensis: waiting in the wings.despite strong epidemiological evidence supporting an important role for campylobacter upsaliensis as a human enteropathogen, it remains relatively unknown in the realm of clinical microbiology. clinical studies indicate that infection with this organism usually is associated with benign self-limiting diarrhea. however, more serious illnesses, including spontaneous abortion and hemolytic-uremic syndrome, recently have been associated with human infections. understanding of the virulence properti ...19989665977
campylobacter species and guillain-barré syndrome.since the eradication of polio in most parts of the world, guillain-barré syndrome (gbs) has become the most common cause of acute flaccid paralysis. gbs is an autoimmune disorder of the peripheral nervous system characterized by weakness, usually symmetrical, evolving over a period of several days or more. since laboratories began to isolate campylobacter species from stool specimens some 20 years ago, there have been many reports of gbs following campylobacter infection. only during the past f ...19989665983
etiological study of diarrheal patients in vientiane, lao people's democratic republic.the etiological agents of diarrhea in vientiane, lao people's democratic republic (lao pdr), were studied in the period from october 1996 to august 1997. a total of 880 patients with diarrhea visiting medical facilities were examined for shigella, salmonella, diarrheagenic escherichia coli, vibrio, aeromonas, campylobacter, and rotavirus. shigella spp., heat-stable enterotoxin (st)-producing e. coli, and serogroup-based enteropathogenic e. coli were found to be the main organisms causing diarrhe ...19989665990
associations between heat-stable (o) and heat-labile (hl) serogroup antigens of campylobacter jejuni: evidence for interstrain relationships within three o/hl serovars.a comparative examination of the heat-stable (o) and heat-labile (hl) serogrouping results for 9,024 sporadic human isolates of campylobacter jejuni revealed conserved associations between specific o and hl antigens (o/hl serovars). forty-nine percent of the isolates which grouped for both o and hl antigens belonged to one of three serovars: o 4 complex/hl 1 (17.9%), o 1/hl 2 (16.8%), or o 50/hl 7 (14.5%). other common serovars were o 2/hl 4 (8.3%), o 6/hl 6 (8.1%), o 53/hl 11 (4.5%), o 19/hl 17 ...19989665996
lipopolysaccharides from campylobacter jejuni o:41 strains associated with guillain-barré syndrome exhibit mimicry of gm1 ganglioside.three campylobacter jejuni, biotype 2, serotype o:41 strains that were isolated from patients who developed guillain-barré syndrome (gbs) and one c. jejuni isolate from a patient who developed enteritis only were examined. the aim of the study was to determine the structure of the core oligosaccharide (os) of the lipopolysaccharide (lps) of c. jejuni serotype o:41, a serotype rarely associated with the development of gbs, and to determine if the lps shares similar epitopes with any of the major ...19989673245
phospholipase a of yersinia enterocolitica contributes to pathogenesis in a mouse model.some isolates of yersinia enterocolitica exhibit phospholipase activity, which has been linked to lecithin-dependent hemolysis (m. tsubokura, k. otsoki, i. shimohira, and h. yamamoto, infect. immun. 25:939-942, 1979). a gene encoding y. enterocolitica phospholipase was identified, and analysis of the nucleotide sequence revealed two tandemly transcribed open reading frames. the first, ypla, has 74% identity and 85% similarity to the phospholipase a found in serratia liquefaciens. though the othe ...19989673284
incidence and clinical manifestations of campylobacter enteritis in central taiwan.campylobacter species are recognized as a major cause of acute gastroenteritis in humans throughout the world and are increasingly associated with the development of guillain-barré syndrome. the age distribution of persons and the seasonal patterns of campylobacter infection are different in many developed and developing countries. the present study reports the investigation of the clinical and epidemiologic features of campylobacter infections in central taiwan.19989684510
antimicrobial resistance of clinical strains of campylobacter jejuni subsp. jejuni isolated from 1985 to 1997 in quebec, canada.the antimicrobial resistance of 158 campylobacter jejuni strains isolated from humans in quebec, canada, from 1995 to 1997 was compared to the resistance of 47 and 86 strains of c. jejuni isolated in 1985 and 1986 and in 1992 and 1993, respectively. of the 291 c. jejuni strains tested, no strain was resistant to erythromycin. compared to the c. jejuni strains isolated in 1985 and 1986, the c. jejuni strains isolated in 1992 and 1993 were more resistant to tetracycline (40.7 versus 19.1%, respect ...19989687415
mammalian cytidine 5'-monophosphate n-acetylneuraminic acid synthetase: a nuclear protein with evolutionarily conserved structural motifs.sialic acids of cell surface glycoproteins and glycolipids play a pivotal role in the structure and function of animal tissues. the pattern of cell surface sialylation is species- and tissue-specific, is highly regulated during embryonic development, and changes with stages of differentiation. a prerequisite for the synthesis of sialylated glycoconjugates is the activated sugar-nucleotide cytidine 5'-monophosphate n-acetylneuraminic acid (cmp-neu5ac), which provides a substrate for golgi sialylt ...19989689047
the lipopolysaccharide biosynthesis locus of campylobacter jejuni 81116.most campylobacter jejuni strains express lipo-oligosaccharides. some strains also express lipopolysaccharides (lps), with o-antigen-like carbohydrate repeats. c. jejuni 81116 expresses an lps containing both lipo-oligosaccharides and o-antigen-like repeats, but nothing is known about the structure or sugar composition of these lps species. a cosmid library of the genome of c. jejuni 81116 was constructed and probed with campylobacter hyoilei genes involved in lps synthesis. five cosmids hybridi ...19989720026
metronidazole resistance and microaerophily in campylobacter species.metronidazole is active against most anaerobic organisms and is also used in the treatment of the microaerophilic bacterium helicobacter pylori. resistance to metronidazole is uncommon in most anaerobic organisms, but it is increasingly prevalent in h. pylori. previously we have suggested that metronidazole resistance in h. pylori is inherent in the microaerophilic nature of the organism and therefore would be present in other microaerophiles such as campylobacter. short periods of anaerobiosis ...19989732442
in vitro genotypic variation of campylobacter coli documented by pulsed-field gel electrophoretic dna profiling: implications for epidemiological studies.six isolates of campylobacter coli from different pig herds were subcultured up to 50 times over a 6-month period and dna samples suitable for pulsed-field gel electrophoretic (pfge) profiling prepared at regular (1, 20, 40 and 50 passages) intervals. in 5/6 strains, changes in the banding patterns of sma1, sal1 and/or bamh1 digests were observed. in one such strain the differences were considered artifactual. however, significant alterations in pfge profiles between subcultures of four strains ...19989742707
resistance to antimicrobial agents used for animal therapy in pathogenic-, zoonotic- and indicator bacteria isolated from different food animals in denmark: a baseline study for the danish integrated antimicrobial resistance monitoring programme (danmap).this study describes the establishment and first results of a continuous surveillance system of antimicrobial resistance among bacteria isolated from pigs, cattle and broilers in denmark. the three categories of bacteria tested were: 1) indicator bacteria (escherichia coli, enterococcus faecalis, enterococcus faecium), 2) zoonotic bacteria (campylobacter coli/jejuni, salmonella enterica, yersinia enterocolitica), and 3) animal pathogens (e. coli, staphylococcus aureus, coagulase-negative staphyl ...19989744762
nucleotide sequence and characterization of cdra, a cell division-related gene of helicobacter pylori.we identified cell division-related gene cdra in helicobacter pylori hpk5. the putative gene product, cdra, is a 367-amino-acid polypeptide that exhibited a high level of homology to conserved hypothetical atp-binding protein hp0066 of h. pylori 26695, except in the n-terminal region, and showed some similarity to the ftsk/spoiiie family proteins. we isolated a cdra-disrupted mutant by allelic exchange mutagenesis. because of the low transformation frequency, the possibility that a suppressing m ...19989748467
identification of a gene encoding a methyl-accepting chemotaxis-like protein form campylobacter coli and its use in a molecular typing scheme for campylobacters.using pcr amplification with degenerate primers, a gene (tlpa) form campylobacter coli encoding a putative 63x0 kda polypeptide which exhibited significant identity with bacterial methyl-accepting chemotaxis proteins (mcps) was identified. a mutant containing an inactivated copy of the tlpa a gene showed a wild-type chemotactic response to all of the chemo-attractants tested. a dna probe based on the highly conserved domain (hcd) of tlpa revealed the presence of multiple copies of genes encoding ...19989750306
physiological activity of campylobacter jejuni far below the minimal growth temperature.the behavior of campylobacter jejuni at environmental temperatures was examined by determining the physiological activities of this human pathogen. the minimal growth temperatures were found to be 32 and 31 degrees c for strains 104 and atcc 33560, respectively. both strains exhibited a sudden decrease in growth rate from the maximum to zero within a few degrees not only near the maximal growth temperature but also near the minimal growth temperature. this could be an indication that a temperatu ...19989758819
effective recovery of bacterial dna and percent-guanine-plus-cytosine-based analysis of community structure in the gastrointestinal tract of broiler chickens.a dna-based, direct method for initial characterization of the total bacterial community in ileum and cecum of the chicken gastrointestinal (gi) tract was developed. the efficiencies of bacterial extraction and lysis were >95 and >99%, respectively, and therefore the dna recovered should accurately reflect the bacterial communities of the ileal and cecal digesta. total bacterial dna samples were fractionated according to their percent g+c content. the profiles reflecting the composition of the b ...19989758849
use of a selective medium and a membrane filter method for isolation of campylobacter species from spanish paediatric patients.a study was conducted to assess the value of a combination of two culture methods for isolation of campylobacter spp. from spanish children. seven hundred twenty-nine diarrhoeal stool specimens from 599 patients were examined for campylobacter spp. by culturing them on charcoal cefoperazone deoxycholate agar and on blood agar with a membrane filter. one hundred sixteen campylobacter strains were isolated from a total of 108 specimens; 75 (64.6%) were campylobacter jejuni, 32 (27.5%) were campylo ...19989764551
iron-responsive gene regulation in a campylobacter jejuni fur mutant.the expression of iron-regulated systems in gram-negative bacteria is generally controlled by the fur protein, which represses the transcription of iron-regulated promoters by using fe2+ as a cofactor. mutational analysis of the campylobacter jejuni fur gene was carried out by generation of a set of mutant copies of fur which had a kanamycin or chloramphenicol resistance gene introduced into the regions encoding the n and c termini of the fur protein. the mutated genes were recombined into the c ...19989765558
[relapsing campylobacter coli bacteremia in a hypogammaglobulinemic patient]. 19989767813
detection of point mutations associated with resistance of helicobacter pylori to clarithromycin by hybridization in liquid phase.when the standard procedure for determining antibiotic susceptibility of bacteria is used, the results are delayed, especially for bacteria that grow slowly, such as helicobacter pylori. treatment for this bacterium may involve clarithromycin, a compound for which resistance has been associated with point mutations on the 23s rrna gene. this resistance is currently found in organisms isolated from 0 to 15% of patients and jeopardizes the success of the treatment. we have designed a test involvin ...19989774580
a reverse transcriptase polymerase chain reaction assay for the detection of thermophilic campylobacter spp.a novel method was developed for the detection of thermophilic enteropathogenic campylobacters based on the detection of mrna using the reverse transcriptase polymerase chain reaction (rt-pcr). the rna extraction method, dnase treatment and rt-pcr assay were shown to be specific for mrna. the assay is specific for the thermophilic campylobacters campylobacter jejuni, campylobacter coli and campylobacter upsaliensis and restriction fragment length polymorphism (rflp) analysis of the 256 bp amplif ...19989778457
deletion of the major proteolytic site of the helicobacter pylori cytotoxin does not influence toxin activity but favors assembly of the toxin into hexameric structures.the helicobacter pylori cytotoxin is proteolytically cleaved at a flexible hydrophilic loop into two subunits. deletion of the loop sequences had no effect on biological activity of the toxin in the hela cell vacuolation assay but favored the organization of the protein into hexameric rather than heptameric structures.19989784571
cloning, sequencing, and characterization of the lipopolysaccharide biosynthetic enzyme heptosyltransferase i gene (waac) from campylobacter jejuni and campylobacter coli.campylobacter jejuni and campylobacter coli are common causes of gastrointestinal disease and a proportion of c. jejuni infections have been shown to be associated with the guillain-barré syndrome. the waac gene from campylobacter coli, involved in lipopolysaccharide core biosynthesis, was cloned by complementation of a heptose-deficient strain of salmonella typhimurium, as judged by novobiocin sensitivity, lipopolysaccharide (lps)-specific phage sensitivity, and polyacrylamide-resolved lipopoly ...19989831648
high-level resistance to trimethoprim in clinical isolates of campylobacter jejuni by acquisition of foreign genes (dfr1 and dfr9) expressing drug-insensitive dihydrofolate reductases.the pathogenic bacterium campylobacter jejuni has been regarded as endogenously resistant to trimethoprim. the genetic basis of this resistance was characterized in two collections of clinical isolates of c. jejuni obtained from two different parts of sweden. the majority of these isolates were found to carry foreign dfr genes coding for resistant variants of the dihydrofolate reductase enzyme, the target of trimethoprim. the resistance genes, found on the chromosome, were dfr1 and dfr9. in abou ...19989835491
rapid emergence of high-level resistance to quinolones in campylobacter jejuni associated with mutational changes in gyra and parc.quinolone resistance in clinical isolates of campylobacter jejuni in sweden increased more than 20-fold at the beginning of the 1990s. resistance to 125 microgram of ciprofloxacin per ml in clinical isolates was associated with chromosomal mutations in c. jejuni leading to a thr-86-ile substitution in the gyra product and a arg-139-gln substitution in the parc product.19989835526
effect of low-osmolality nutrient media on growth and culturability of campylobacter species.the growth and culturability of campylobacter jejuni nctc 11351 and other campylobacters were examined in media having different osmolalities at a range of temperatures (4, 25, and 42 degreesc). the medium osmolalities used ranged from the osmolality of full-strength nutrient medium (modified campylobacter broth having an osmolality of around 254 mosmol) down to 96 mosmol. the following two methods were used to produce media having different osmolalities: dilution of the nutrient medium with dis ...19989835543
a case control study of potential enteric pathogens for calves raised in cow-calf herds.a matched case control study was performed to describe the epidemiological features of potential enteric pathogens for calves reared in 53 cow-calf herds located in western switzerland. a total of 106 diarrhoeic calves and 126 healthy control calves were collected, all calves were less than 4 months old. faecal samples were analysed for presence of infectious agents related to calf diarrhoea including enterotoxigenic e. coli, verotoxin producing e. coli (vtec), campylobacter sp., yersinia sp., s ...19989852767
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 ...19999882675
pcr-enzyme-linked immunosorbent assay for detection and identification of campylobacter species: application to isolates and stool samples.we report a pcr-enzyme-linked immunosorbent assay which identifies campylobacter species by capture hybridization of a single-stranded 16s rrna gene amplicon with species-specific probes in a microtiter plate format. specificities were confirmed for both reference and field strains, but the type strain of campylobacter coli was atypical. the assay was rapid, informative, and usable with stool-extracted dna.19999889235
identification of the enteropathogens campylobacter jejuni and campylobacter coli based on the cadf virulence gene and its product.campylobacter jejuni and campylobacter coli are common causes of gastroenteritis in humans. infection with c. jejuni or c. coli is commonly acquired by eating undercooked chicken. the goal of this study was to develop specific detection assays for c. jejuni and c. coli isolates based on the cadf virulence gene and its product. the cadf gene from c. jejuni and c. coli encodes a 37-kda outer membrane protein that promotes the binding of these pathogens to intestinal epithelial cells. a fragment of ...19999986804
characterization of human bactericidal antibodies to bordetella pertussis.the bordetella pertussis brka protein protects against the bactericidal activity of complement and antibody; however, some individuals mount an immune response that overcomes this bacterial defense. to further characterize this process, the bactericidal activities of sera from 13 adults with different modes of exposure to b. pertussis (infected as adults, occupational exposure, immunized with an acellular vaccine, or no identified exposure) against a wild-type strain and a brka complement-sensit ...199910024590
inducing enterotoxigenic properties in campylobacter jejuni and campylobacter coli by serial intraperitoneal passage in mice. 199910029919
comparison of flagellin genes from clinical and environmental pseudomonas aeruginosa isolates.pseudomonas aeruginosa, an important opportunistic pathogen, was isolated from environmental samples and compared to clinically derived strains. while p. aeruginosa was isolated readily from an experimental mushroom-growing unit, it was found only rarely in other environmental samples. a flagellin gene pcr-restriction fragment length polymorphism analysis of the isolates revealed that environmental and clinical p. aeruginosa strains are not readily distinguishable. the variation in the central r ...199910049879
evaluation of accuracy and repeatability of identification of food-borne pathogens by automated bacterial identification systems.the performances of five automated microbial identification systems, relative to that of a reference identification system, for their ability to accurately and repeatedly identify six common food-borne pathogens were assessed. the systems assessed were the microlog system (biolog inc., hayward, calif.), the microbial identification system (mis; midi inc., newark, del.), the vitek system (biomérieux vitek, hazelwood, mo.), the microscan walkaway 40 system (dade-microscan international, west sacra ...199910074506
mutational analysis of the vaca promoter provides insight into gene transcription in helicobacter pylori.analysis of 12 helicobacter pylori promoters indicates the existence of a consensus -10 hexamer (tataat) but little conservation of -35 sequences. in this study, mutations in either the h. pylori vaca -10 region or the -35 region resulted in decreased vaca transcription and suggested that an extended -10 motif is utilized. thus, despite the lack of a -35 consensus sequence for h. pylori promoters, the -35 region plays a functional role in vaca transcription.199910094707
serotypes and typability of campylobacter jejuni and campylobacter coli isolated from poultry products.campylobacter infection is one of the most common bacterial enteric pathogens. campylobacter jejuni and campylobacter coli infections are mostly food- and waterborne and especially poultry is often assumed to be an important source. the heat-stable serotyping system (the 'penner' scheme) was used to study the serotype distribution of c. jejuni and c. coli isolated from different food products of poultry origin sampled from retail outlets in denmark. a total of 156 isolates were serotyped, 85% of ...199910100900
fluoroquinolone resistance in salmonellas and campylobacters from humans. 199910102879
detection of cytolethal distending toxin activity and cdt genes in campylobacter spp. isolated from chicken carcasses.this study was designed to determine whether isolates from chicken carcasses, the primary source of campylobacter jejuni and campylobacter coli in human infections, commonly carry the cdt genes and also whether active cytolethal distending toxin (cdt) is produced by these isolates. campylobacter spp. were isolated from all 91 fresh chicken carcasses purchased from local supermarkets. campylobacter spp. were identified on the basis of both biochemical and pcr tests. of the 105 isolates, 70 (67%) ...199910103243
detection of small numbers of campylobacter jejuni and campylobacter coli cells in environmental water, sewage, and food samples by a seminested pcr assay.a rapid and sensitive assay was developed for detection of small numbers of campylobacter jejuni and campylobacter coli cells in environmental water, sewage, and food samples. water and sewage samples were filtered, and the filters were enriched overnight in a nonselective medium. the enrichment cultures were prepared for pcr by a rapid and simple procedure consisting of centrifugation, proteinase k treatment, and boiling. a seminested pcr based on specific amplification of the intergenic sequen ...199910103261
cytolethal distending toxin genes in campylobacter jejuni and campylobacter coli isolates: detection and analysis by pcr.campylobacter jejuni produces a toxin called cytolethal distending toxin (cdt). knowledge of the prevalence and homogeneity of campylobacter sp. cdt genes is incomplete. in this work, we identified four pcr primer pairs that collectively amplified cdt genes in all of the c. jejuni and campylobacter coli strains tested. restriction analyses of the cdt pcr products showed clear differences between the cdt genes of these two species, yet there were few heterogeneities noted between members of the s ...199910203548
differentiation of campylobacter coli and c. jejuni by length and dna sequence of the 16s-23s rrna internal spacer region.the internal spacer region (isr) between the 16s and 23s rrna genes of campylobacter was investigated by pcr fragment length typing and dna sequencing of clinical and chicken wild-type isolates. pcr fragment length typing showed one fragment of 859 nt in length for the 12 strains of campylobacter coli investigated. thirty-six of the campylobacter jejuni subsp. jejuni strains possessed one fragment, which varied in size between 727 and 802 nt. three strains showed two fragments between 501 and 92 ...199910206715
the use of hipo, encoding benzoylglycine amidohydrolase (hippuricase), as a reporter of gene expression in campylobacter coli.a novel integrative promoter probe vector which utilizes the campylobacter jejuni hipo gene as a reporter of gene expression was developed as a genetic tool in campylobacter coli. the utility of the system was demonstrated by coupling expression of the hipo reporter to the promoters of flaa, flab and kata. subsequently, expression of these genes could be monitored accurately from chromosomally-borne transcriptional fusions using a simple non-destructive colorimetric assay. the system should serv ...199910212441
survival times of campylobacter coli in sterilized buffalo milk.the survival level of five campylobacter coli strains isolated from bovine faeces was studied in sterilized buffalo milk kept at 4 degrees c under aerobic conditions. all strains died between 21 and 30 h of storage.199910216458
ferric enterobactin binding and utilization by neisseria gonorrhoeae.feta, formerly designated frpb, an iron-regulated, 76-kda neisserial outer membrane protein, shows sequence homology to the tonb-dependent family of receptors that transport iron into gram-negative bacteria. although feta is commonly expressed by most neisserial strains and is a potential vaccine candidate for both neisseria gonorrhoeae and neisseria meningitidis, its function in cell physiology was previously undefined. we now report that feta functions as an enterobactin receptor. n. gonorrhoe ...199910217784
high-resolution genomic fingerprinting of campylobacter jejuni and campylobacter coli by analysis of amplified fragment length polymorphisms.a method for high-resolution genomic fingerprinting of the enteric pathogens campylobacter jejuni and campylobacter coli, based on the determination of amplified fragment length polymorphism, is described. the potential of this method for molecular epidemiological studies of these species is evaluated with 50 type, reference, and well-characterised field strains. amplified fragment length polymorphism fingerprints comprised over 60 bands detected in the size range 35-500 bp. groups of outbreak s ...199910220884
cloning and characterization of polyphosphate kinase and exopolyphosphatase genes from pseudomonas aeruginosa 8830.pseudomonas aeruginosa accumulates polyphosphates in response to nutrient limitations. to elucidate the function of polyphosphate in this microorganism, we have investigated polyphosphate metabolism by isolating from p. aeruginosa 8830 the genes encoding polyphosphate kinase (ppk) and exopolyphosphatase (ppx), which are involved in polyphosphate synthesis and degradation, respectively. the 690- and 506-amino-acid polypeptides encoded by the two genes have been expressed in escherichia coli and p ...199910224002
stability of related human and chicken campylobacter jejuni genotypes after passage through chick intestine studied by pulsed-field gel electrophoresis.the genomic stability of 12 campylobacter jejuni strains consisting of two groups of human and chicken isolates was studied by analysis of their pfge (pulsed-field gel electrophoresis) patterns after passage through newly hatched chicks' intestines. the patterns of smai, sali, and sacii digests remained stable after intestinal passage, except for those of two strains. one originally human strain, fb 6371, changed its genotype from ii/a (smai/sacii) to i/b. another strain, bti, originally isolate ...199910224037
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 ...199910225906
study of the presence of campylobacter jejuni and c. coli in sand samples from four swiss chicken farms.chicken farms are frequently infected with campylobacter jejuni and campylobacter coli. the objective of the present study was to investigate environmental samples from chicken farms for the presence of c. jejuni and c. coli. every week between july and november 1997, three sand samples from the runs of four chicken farms were analyzed by culture and directly by polymerase chain reaction (pcr). these two detection methods were compared to each other. a total of 231 samples were tested. eleven sa ...199910229951
rapid identification of thermotolerant campylobacter jejuni, campylobacter coli, campylobacter lari, and campylobacter upsaliensis from various geographic locations by a gtpase-based pcr-reverse hybridization assay.recently, a gene from campylobacter jejuni encoding a putative gtpase was identified. based on two semiconserved gtp-binding sites encoded within this gene, pcr primers were selected that allow amplification of a 153-bp fragment from c. jejuni, c. coli, c. lari, and c. upsaliensis. sequence analysis of these pcr products revealed consistent interspecies variation, which allowed the definition of species-specific probes for each of the four thermotolerant campylobacter species. multiple probes we ...199910325325
differentiation of helicobacter pylori isolates based on lectin binding of cell extracts in an agglutination assay.plant and animal lectins with various carbohydrate specificities were used to type 35 irish clinical isolates of helicobacter pylori and the type strain nctc 11637 in a microtiter plate assay. initially, a panel of eight lectins with the indicated primary specificities were used: anguilla anguilla (aaa), lotus tetragonolobus (lotus a), and ulex europaeus i (uea i), specific for alpha-l-fucose; solanum tuberosum (sta) and triticum vulgaris (wga), specific for beta-n-acetylglucosamine; glycine max ...199910325361
septic shock due to helicobacter fennelliae in a non-human immunodeficiency virus-infected heterosexual patient.helicobacter fennelliae (formerly campylobacter fennelliae) has been reported to cause bacteremia in homosexual men with or without human immunodeficiency virus (hiv) infection. we report here a 48-year-old, non-hiv-infected, heterosexual man with diabetes mellitus and cirrhosis of the liver who developed bacteremia and septic shock due to h. fennelliae. the patient was treated successfully initially with intravenous ampicillin-sulbactam and ceftazidime, followed by ampicillin-sulbactam only. th ...199910325388
passive immunity against human pathogens using bovine antibodies. 199910337007
biotin-streptavidin enzyme-linked immunosorbent assay for the detection of antibodies to campylobacter jejuni and c. coli in enzyme-linked immunosorbent assay (elisa) was developed in a homologous system with bacterial ultrasonic-treated proteins as the antigen and antisera from chickens infected orally and subcutaneously with the strain campylobacter jejuni serovar 6 (cj 6). the cut-off level was determined using antisera from non-infected specific-pathogen-free chickens up to the age of 10 weeks. the suitability of the elisa system was verified using antisera taken from chickens orally infected at the age of 4 we ...199910337238
high-resolution genotyping of campylobacter strains isolated from poultry and humans with amplified fragment length polymorphism fingerprinting.for epidemiological studies of campylobacter infections, molecular typing methods that can differentiate campylobacters at the strain level are needed. in this study we used a recently developed genotyping method, amplified fragment length polymorphism (aflp), which is based on selective amplification of restriction fragments of chromosomal dna, for genetic typing of campylobacter jejuni and campylobacter coli strains derived from humans and poultry. we developed an automated aflp fingerprinting ...199910347015
generation of a superoxide dismutase (sod)-deficient mutant of campylobacter coli: evidence for the significance of sod in campylobacter survival and colonization.the microaerophilic nature of campylobacter species implies an inherent sensitivity towards oxygen and its reduction products, particularly the superoxide anion. the deleterious effects of exposure to superoxide radicals are counteracted by the activity of superoxide dismutase (sod). we have shown previously that campylobacter coli possesses an iron cofactored sod. the sodb gene of c. coli ua585 was insertionally inactivated by the site-specific insertion of a teto cassette. organisms harboring ...199910347040
evaluation of the anaeropack campylo system for growth of microaerophilic bacteria.growth of microaerophilic bacteria in the anaeropack campylo (mitsubishi gas chemical america, inc., new york, n.y.) atmosphere generation system was compared to growth in the campypak plus jar and campypak pouch (becton-dickinson microbiology systems [bdms], cockeysville, md.). growth in the anaeropack campylo system was considered equivalent to or better than growth obtained in the campypak plus and campypak pouch systems for 48 of the 50 helicobacter pylori strains and for all 28 campylobacte ...199910364622
campylobacter coli strains with enlarged flagellin genes isolated from river water.a group of campylobacters isolated from river water were found to possess unusually large flagellin genes. both phenotype and serology were consistent with identification as campylobacter coli. phylogenetic analysis of small (16s, rrs) and large subunit (23s, rrl) rrna genes of a representative strain, nctc 13006, demonstrated high levels of relatedness with c. jejuni and c. coli (99.1 and 98.3% similarity for 16s; 99.3 and 99.4% similarity for 23s). large flagellin proteins were demonstrated by ...199910376486
in-vitro activity of moxifloxacin against fluoroquinolone-resistant strains of aerobic gram-negative bacilli and enterococcus faecalis.mics of the new fluoroquinolone, moxifloxacin, and those of ciprofloxacin, ofloxacin and sparfloxacin for 19 genetically characterized fluoroquinolone-resistant strains were determined by the agar dilution method. the mics of moxifloxacin for escherichia isolates with one mutation in gyra (corresponding to ser83-->leu or asp87-->gly substitution) were 0.25-0.5 mg/l, while those of ciprofloxacin, ofloxacin and sparfloxacin were 0.06-0.25, 1 and 0.12-0.5 mg/l, respectively. these values were four- ...199910382871
evaluation of the effect of temperature and nutrients on the survival of campylobacter spp. in water microcosms.batch microcosms containing various water types (de-ionized and river water with or without sediment), incubated at a range of temperatures (5-37 degrees c), were used to facilitate a comparative evaluation of the significance of such variables and their interactions upon the collective and individual survival of four species of thermophilic campylobacter. all variables significantly influenced (p < = 0.031) population decay rates. minimal decay for the group was identified at low temperatures ( ...199910389249
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 ...199910390244
identification of a glycoprotein produced by enterotoxigenic escherichia coli.enterotoxigenic escherichia coli (etec) strain h10407 is capable of invading epithelial cell lines derived from the human ileocecum and colon in vitro. two separate chromosomally encoded invasion loci (tia and tib) have been cloned from this strain. these loci direct nonadherent and noninvasive laboratory strains of e. coli to adhere to and invade cultured human intestinal epithelial cells. the tib locus directs the synthesis of tiba, a 104-kda outer membrane protein that is directly correlated ...199910417177
campylobacter jejuni 81-176 associates with microtubules and dynein during invasion of human intestinal cells.campylobacter jejuni uptake into cultured int407 cells was analyzed kinetically over a wide range of starting multiplicities of infection (moi; from 0.02 to 20,000 bacteria/epithelial cell). the efficiency of internalization was the highest at moi of 0.02 and decreased steadily at higher mois, presumably due to reported c. jejuni autoagglutination at higher densities. total internalized campylobacter cfu increased gradually from an moi of 0.02 to a peak at an moi of 200 (reaching an average of t ...199910417189
occurrence, removal and seasonal variation of thermophilic campylobacters and arcobacter in sewage sludge.the presence of thermophilic campylobacters and arcobacter was investigated in four types of sewage sludge taken from the treatment plant in bologna (italy): primary, activated, thickened and anaerobically digested sludge. campylobacter jejuni and campylobacter coli were more numerous during the march-september period and were found only in primary sludge (22.7%) with mean counts of 278 mpn/g dry matter and 1403 mpn/g dry matter respectively. arcobacter butzleri were found in all types of sludge ...199910418097
incidence of salmonella, campylobacter jejuni, campylobacter coli, and listeria monocytogenes in poultry carcasses and different types of poultry products for sale on the belgian retail market.from january 1997 to may 1998, 772 samples of poultry carcasses and poultry products for sale on the retail market in belgium were analyzed for the presence of salmonella spp., salmonella enteritidis, campylobacter jejuni, c. coli, and listeria monocytogenes per 100 cm2 or 25 g. poultry samples were contaminated with salmonella (36.5%), c. jejuni and c. coli (28.5%), and l. monocytogenes (38.2%). in about 12.3% of the poultry samples, the l. monocytogenes contamination level exceeded 1 cfu per g ...199910419264
an iron-regulated alkyl hydroperoxide reductase (ahpc) confers aerotolerance and oxidative stress resistance to the microaerophilic pathogen campylobacter jejuni.microaerophiles like campylobacter jejuni must resist oxidative stresses during transmission or infection. growth of c. jejuni 81116 under iron limitation greatly increased the expression of two polypeptides of 26 and 55 kda. the identification of these proteins by n-terminal amino acid sequencing showed both to be involved in the defense against oxidative stress. the 55-kda polypeptide was identical to c. jejuni catalase (kata), whereas the n terminus of the 26-kda polypeptide was homologous to ...199910438747
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 ...199910464475
sulfonamide resistance in clinical isolates of campylobacter jejuni: mutational changes in the chromosomal dihydropteroate synthase.the characterization of the genetic basis of sulfonamide resistance in campylobacter jejuni was attempted. the resistance determinant from a sulfonamide-resistant strain of c. jejuni was cloned and was found to show 42% identity with the folp gene (which codes for dihydropteroate synthase, the target of sulfonamides) of the related bacterium helicobacter pylori. the sequences of the areas surrounding the folp gene in c. jejuni showed similarity to those of the areas surrounding the corresponding ...199910471557
metabolism and genetics of helicobacter pylori: the genome era.the publication of the complete sequence of helicobacter pylori 26695 in 1997 and more recently that of strain j99 has provided new insight into the biology of this organism. in this review, we attempt to analyze and interpret the information provided by sequence annotations and to compare these data with those provided by experimental analyses. after a brief description of the general features of the genomes of the two sequenced strains, the principal metabolic pathways are analyzed. in particu ...199910477311
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 ...199910482496
the c-terminal domain of the bordetella pertussis autotransporter brka forms a pore in lipid bilayer membranes.brka is a 103-kda outer membrane protein of bordetella pertussis that mediates resistance to antibody-dependent killing by complement. it is proteolytically processed into a 73-kda n-terminal domain and a 30-kda c-terminal domain as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. brka is also a member of the autotransporter family of proteins. translocation of the n-terminal domain of the protein across the outer membrane is hypothesized to occur through a pore formed by ...199910482528
recombinant single-chain fv antibody fragment-alkaline phosphatase conjugate for one-step immunodetection in molecular hybridization.using phage-display technology, a recombinant single-chain fv antibody fragment (scfv) was rapidly generated from the k16-16 hybridoma secreting mouse monoclonal antibody (mab) that binds to acetylaminofluorene-labeled dna (aaf-dna). the selected a4 phage-scfv specifically bound to aaf-dna. the anti-aaf scfv gene was then recloned into a fusion vector for the production of a hybrid protein comprising the antibody fragment fused to a potent bacterial alkaline phosphatase variant (phoav). the anti ...199910485265
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