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use of a rabbit soft tissue chamber model to investigate campylobacter jejuni-host interactions.despite the prevalence of campylobacter jejuni as an important food borne pathogen, the microbial factors governing its infection process are poorly characterized. in this study, we developed a novel rabbit soft tissue chamber model to investigate c. jejuni interactions with its host. the in vivo transcriptome profile of c. jejuni was monitored as a function of time post-infection by competitive microarray hybridization with cdna obtained from c. jejuni grown in vitro. genome-wide expression ana ...201021687769
phages in nature.bacteriophages or phages are the most abundant organisms in the biosphere and they are a ubiquitous feature of prokaryotic existence. a bacteriophage is a virus which infects a bacterium. archaea are also infected by viruses, whether these should be referred to as 'phages' is debatable, but they are included as such in the scope this article. phages have been of interest to scientists as tools to understand fundamental molecular biology, as vectors of horizontal gene transfer and drivers of bact ...201121687533
diagnostic value of anti-gq1b antibodies in a patient with relapsing dysarthria and ataxia.serum antibodies to the ganglioside gq1b are associated with immune-mediated ophthalmoplegia and ataxia in patients with miller-fisher syndrome (mfs) and guillain-barré syndrome. a patient with two clinically similar episodes of progressive bulbar signs, ophthalmoplegia and ataxia is reported here. during both episodes the patient required artificial ventilation. serum anti-gq1b antibodies were detected during the first episode compatible with mfs, but were absent during the second. neuroradiolo ...200921686634
genome sequence of campylobacter jejuni strain 327, a strain isolated from a turkey slaughterhouse.campylobacter is one of the leading causes of food-borne gastroenteritis and has a high prevalence in poultry. campylobacter jejuni subsp. jejuni 327 is a subspecies of the genus campylobacter of the family campylobacteraceae in the phylum proteobacteria. the microaerophilic, spiral shaped, catalase positive bacterium obtains energy from the metabolism of amino acids and krebs cycle intermediates. strain 327 was isolated from a turkey slaughter production line and is considered environmentally s ...201121677848
identification of persistent subtypes of campylobacter jejuni by pulsed-field gel electrophoresis in finland.abstract the genetic diversity of campylobacter jejuni strains isolated from finnish patients was studied by typing 508 strains by pulsed-field gel electrophoresis: 311 were isolated from domestically acquired infections and 197 from travel-related infections. the strains were systematically selected from a larger collection of previously serotyped strains isolated during two 1-year sampling periods. the four most common smai profiles accounted for 45% of the domestic strains but only 3% of the ...201121675864
structural diversity of bacterial flagellar motors.the bacterial flagellum is one of nature's most amazing and well-studied nanomachines. its cell-wall-anchored motor uses chemical energy to rotate a microns-long filament and propel the bacterium towards nutrients and away from toxins. while much is known about flagellar motors from certain model organisms, their diversity across the bacterial kingdom is less well characterized, allowing the occasional misrepresentation of the motor as an invariant, ideal machine. here, we present an electron cr ...201121673657
exposure assessment and process sensitivity analysis of the contamination of campylobacter in poultry products.studies were conducted in a thai poultry plant to identify the factors that affected numbers of campylobacter jejuni in chicken carcasses. the concentrations of campylobacter were determined using the simplate most probable number and modified charcoal cefoperazone deoxycholate plating methods. results indicated that the mean concentrations of c. jejuni in carcasses after scalding, plucking, and chilling were 2.93 ┬▒ 0.31, 2.98 ┬▒ 0.38, 2.88 ┬▒ 0.31, and 0.85 ┬▒ 0.95 log cfu, whereas the concent ...201121673173
molecular epidemiology and antimicrobial susceptibility of campylobacter jejuni and campylobacter coli isolates of poultry, swine, and cattle origin collected from slaughterhouses in hungary.campylobacter spp. are the most common cause of bacterial enteritis in hungary, and the aim of this study was to identify the distribution, genotypes, and antimicrobial susceptibility of campylobacter species in the most important food-producing animals at the time of slaughter during 2008 and 2009. of 1,110 samples, 266 were identified as campylobacter coli (23.9%) and 143 as c. jejuni (12.9%) by real-time pcr. resistance to enrofloxacin-ciprofloxacin and nalidixic acid was significant, especia ...201121669066
a sulfite respiration pathway from thermus thermophilus and the key role of newly identified cytochrome côéàôéàôéç.sulfite, produced for instance during amino acid metabolism, is a very reactive and toxic compound. various detoxification mechanisms exist, but sulfite oxidoreductases (sors) are one of the major actors in sulfite remediation in bacteria and animals. here we describe the existence of an operon in the extreme thermophilic bacterium thermus thermophilus hb8 encoding both a sor and a diheme c-type cytochrome. the in vitro analysis clearly showed that the newly identified cytochrome côéàôéàôéç acts ...201121665981
the luxs mutation causes loosely-bound biofilms in shewanella oneidensis.abstract:201121663678
outbreak of campylobacteriosis associated with consumption of raw peas.campylobacter jejuni is a leading cause of acute gastroenteritis worldwide, and most cases are identified as sporadic events rather than as parts of recognized outbreaks. we report findings from a substantial 2008 campylobacteriosis outbreak with general implications for fresh produce safety.201121653299
detection of influenza viral gene in european starlings and experimental infection.european starlings (sturnus vulgaris) are common, widely distributed birds in north america that frequently come into contact with agricultural operations. however, starlings have been one of the neglected land-based wild bird species for influenza surveillance.201121651737
detection of influenza viral gene in european starlings and experimental infection.european starlings (sturnus vulgaris) are common, widely distributed birds in north america that frequently come into contact with agricultural operations. however, starlings have been one of the neglected land-based wild bird species for influenza surveillance.201121651737
rotavirus diarrhea among children less than 5 years of age in urban ghana.we collected clinical and morphologic data from children with diarrhea attending 3 diverse hospitals/clinics in accra. stool samples were tested for rotavirus and cryptosporidium spp. in all, 58% of the children with diarrhea had rotavirus infections, 25% of which were of the g3 sero/genotype. the most common strains were g3p [6] (18.8%) and g2p [6] (12.5%). cryptosporidium spp. infections were uncommon (3/143, 2.0%).201121646938
genetic control of biosynthesis and transport of riboflavin and flavin nucleotides and construction of robust biotechnological producers.summary: riboflavin [7,8-dimethyl-10-(1'-d-ribityl)isoalloxazine, vitamin b(2)] is an obligatory component of human and animal diets, as it serves as the precursor of flavin coenzymes, flavin mononucleotide, and flavin adenine dinucleotide, which are involved in oxidative metabolism and other processes. commercially produced riboflavin is used in agriculture, medicine, and the food industry. riboflavin synthesis starts from gtp and ribulose-5-phosphate and proceeds through pyrimidine and pteridi ...201121646432
the salmonella enterica pan-genome.salmonella enterica is divided into four subspecies containing a large number of different serovars, several of which are important zoonotic pathogens and some show a high degree of host specificity or host preference. we compare 45 sequenced s. enterica genomes that are publicly available (22 complete and 23 draft genome sequences). of these, 35 were found to be of sufficiently good quality to allow a detailed analysis, along with two escherichia coli strains (k-12 substr. dh10b and the avian p ...201121643699
tubal factor infertility is associated with antibodies against chlamydia trachomatis heat shock protein 60 (hsp60) but not human hsp60.background serum antibodies against major outer membrane protein (momp) and heat shock protein 60 (hsp60) from chlamydia trachomatis are correlated with sequelae following infection. since bacterial and human hsp60 share considerable sequence homology, cross-reactivity to human hsp60 is suggested as being involved in tubal factor infertility (tfi). the aim was to investigate whether antibodies to human hsp60 are associated with tfi, and to evaluate antibody testing in tfi diagnosis. methods seru ...201121642639
the campylobacter jejuni transcriptional regulator cj1556 plays a role in the oxidative and aerobic (o2) stress response and is important for bacterial survival in vivo.campylobacter jejuni is the leading bacterial cause of human gastroenteritis worldwide. despite stringent microaerobic growth requirements, c. jejuni is ubiquitous in the aerobic environment, so must possess regulatory systems to sense and adapt to external stimuli such as oxidative and aerobic (o(2)) stress. re-annotation of the c. jejuni nctc11168 genome sequence identified cj1556 (originally annotated as a hypothetical protein) as a marr family transcriptional regulator and further analysis i ...201121642451
investigating antibacterial mechanisms of garlic (allium sativum) concentrate and garlic-derived organosulfur compounds on campylobacter jejuni using ft-ir spectroscopy, raman spectroscopy and electron microscope.fourier transform infrared (ft-ir) spectroscopy and raman spectroscopy were used to study the cell injury and inactivation of campylobacter jejuni from exposure to antioxidants from garlic. c. jejuni was treated with various concentration of garlic concentrate and garlic derived organosulfur compounds in growth media and saline at 4, 22 and 35°c. antimicrobial activity of the diallyl sulfides increased with the number of sulfur atoms (diallyl sulfide < diallyl disulfide < diallyl trisulfide). ft ...201121642409
a breathtaking feat: to compete with the gut microbiota, salmonella drives its host to provide a respiratory electron acceptor.salmonella is a common cause of food poisoning. however, after ingestion the pathogen has to compete with resident microbes that already occupy the intestinal lumen (microbiota), which poses a challenge for salmonella to successfully colonize this niche. recent data show that salmonella elicits help from the host immune response to beat the competition. after arriving in the intestine, salmonella elicits acute intestinal inflammation. the respiratory burst of neutrophils that transmigrate into t ...201021637020
role of lipid rafts in liver health and disease.liver diseases are an increasingly common cause of morbidity and mortality; new approaches for investigation of mechanisms of liver diseases and identification of therapeutic targets are emergent. lipid rafts (lrs) are specialized domains of cellular membranes that are enriched in saturated lipids; they are small, mobile, and are key components of cellular architecture, protein partition to cellular membranes, and signaling events. lrs have been identified in the membranes of all liver cells, pa ...201121633657
enteric pathogens associated with childhood diarrhea in tripoli-libya.abstract. stool samples from children < 5 years of age with diarrhea (n = 239) were examined for enteric pathogens using a combination of culture, enzyme-immunoassay, and polymerase chain reaction methods. pathogens were detected in 122 (51%) stool samples; single pathogens were detected in 37.2% and co-pathogens in 13.8% of samples. norovirus, rotavirus, and diarrheagenic escherichia coli (dec) were the most frequently detected pathogens (15.5%, 13.4%, and 11.2%, respectively); salmonella, aden ...201121633024
an experimental mouse model to establish tropheryma whipplei as a diarrheal agent.(see the editorial commentary by wilson et al, on pages 4-5.) tropheryma whipplei has long been considered as a rare bacterium causing a rare disease, whipple's disease. however, recent advances now suggest that t. whipplei is a ubiquitous environmental bacterium that may cause gastroenteritis, commonly associated with viral pathogens. we developed an animal model to support this hypothesis. we found that orally given t. whipplei induced diarrhea in mice, without spreading into the intestines. a ...201121628657
glycosylation regulates the specific induction of rice immune responses by acidovorax avenae flagellin.plants have a sensitive system that detects various pathogen-derived molecules to protect against infection. flagellin, a main component of the bacterial flagellum, from the rice avirulent n1141 strain of gram-negative phytopathogenic bacterium, acidovorax avenae, induces plant immune responses including h(2)o(2) generation, while flagellin from the rice virulent k1 strain of a. avenae does not induce these immune responses. to clarify the molecular mechanism that leads to these differing respon ...201121628471
comparison of two commercial ovine campylobacter vaccines and an experimental bacterin in guinea pigs inoculated with campylobacter jejuni.objective-to compare efficacy of 2 commercial ovine campylobacter vaccines and an experimental bacterin in guinea pigs following ip inoculation with campylobacter jejuni ia3902. animals-51 female guinea pigs. procedures-pregnant and nonpregnant animals were randomly assigned to 1 of 4 treatment groups and administered a commercial campylobacter vaccine labeled for prevention of campylobacteriosis in sheep via two 5-ml doses 14 days apart (vaccine a; n = 13), another labeled for prevention of cam ...201121627526
functional characterization of a lipoprotein-encoding operon in campylobacter jejuni.bacterial lipoproteins have important functions in bacterial pathogenesis and physiology. in campylobacter jejuni, a major foodborne pathogen causing gastroenteritis in humans, the majority of lipoproteins have not been functionally characterized. previously, we showed by dna microarray that cmer, a transcriptional regulator repressing the expression of the multidrug efflux pump cmeabc, modulates the expression of a three-gene operon (cj0089, cj0090, and cj0091) encoding a cluster of lipoprotein ...201121625391
global gene disruption in human cells to assign genes to phenotypes by deep sequencing.insertional mutagenesis in a haploid background can disrupt gene function. we extend our earlier work by using a retroviral gene-trap vector to generate insertions in >98% of the genes expressed in a human cancer cell line that is haploid for all but one of its chromosomes. we apply phenotypic interrogation via tag sequencing (phitseq) to examine millions of mutant alleles through selection and parallel sequencing. analysis of pools of cells, rather than individual clones enables rapid assessmen ...201121623355
molecular detection of campylobacter spp. in california gull (larus californicus) excreta.we examined the prevalence, quantity, and diversity of campylobacter species in the excreta of 159 california gull (larus californicus) samples using culture, pcr- and qpcr-based detection assays. campylobacter spp. prevalence and abundance was relatively high in the gull excreta examined; however, c. jejuni and c. lari were detected in less than 2% of the isolates and dna extracts from the fecal samples that tested positive. moreover, molecular and sequencing data indicated that most l. califor ...201121622785
the carbon monoxide-releasing molecule, corm-3 (ru(co)(3) cl(glycinate)), targets respiration and oxidases in campylobacter jejuni, generating hydrogen peroxide.carbon monoxide (co) is a classical respiratory inhibitor, but co-releasing molecules (co-rms) have therapeutic value, increasing phagocytosis, and reducing sepsis-induced lethality. corm-3, ru(co)(3) cl(glycinate), a ruthenium-based carbonyl that liberates co under physiological conditions, has previously been shown to inhibit bacterial growth and respiration, even at high concentrations of oxygen. here, we report the effects of corm-3 on the microaerophilic foodborne pathogen campylobacter jej ...201121618403
multilocus sequence typing of a global collection of pasteurella multocida isolates from cattle and other host species demonstrates niche association.abstract: background: pasteurella multocida causes disease in many host species throughout the world. in bovids, it contributes to bovine respiratory disease (brd) and causes haemorrhagic septicaemia (hs). previous studies have suggested that brd-associated p. multocida isolates are of limited diversity. a multilocus sequence typing (mlst) scheme for p. multocida was used to determine whether the low levels of diversity reported are due to the limited discriminatory power of the typing method us ...201121612618
identification of small-molecule inhibitors of yersinia pestis type iii secretion system yscn atpase.yersinia pestis is a gram negative zoonotic pathogen responsible for causing bubonic and pneumonic plague in humans. the pathogen uses a type iii secretion system (t3ss) to deliver virulence factors directly from bacterium into host mammalian cells. the system contains a single atpase, yscn, necessary for delivery of virulence factors. in this work, we show that deletion of the catalytic domain of the yscn gene in y. pestis co92 attenuated the strain over three million-fold in the swiss-webster ...201121611119
genetic and molecular analyses reveal an evolutionary trajectory for glycan synthesis in a bacterial protein glycosylation system.although protein glycosylation systems are becoming widely recognized in bacteria, little is known about the mechanisms and evolutionary forces shaping glycan composition. species within the genus neisseria display remarkable glycoform variability associated with their o-linked protein glycosylation (pgl) systems and provide a well developed model system to study these phenomena. by examining the potential influence of two orfs linked to the core pgl gene locus, we discovered that one of these, ...201121606362
global gene expression analysis of chicken caecal response to campylobacter jejuni.campylobacter jejuni colonises the caecum of more than 90% of commercial chickens. even though colonisation is asymptomatic, we hypothesised that it is mediated by activation of several biological pathways. we therefore used chicken-specific 20k oligonucleotide microarrays to examine global gene expression in c. jejuni-challenged birds. microarray results demonstrate small but significant fold-changes in expression of 270 genes 20h post-challenge, corresponding to a wide range of biological proc ...201121605915
bacterial syntenies: an exact approach with gene quorum.the automatic identification of syntenies across multiple species is a key step in comparative genomics that helps biologists shed light both on evolutionary and functional problems.201121605461
screening of australian plants for antimicrobial activity against campylobacter jejuni.campylobacter jejuni is the most common cause of acute enteritis in humans, with symptoms such as diarrhoea, fever and abdominal cramps. in this study, 115 extracts from 109 australian plant species were investigated for their antimicrobial activities against two c. jejuni strains using an in vitro broth microdilution assay. among the plants tested, 107 (93%) extracts showed activity at a concentration between 32 and 1024 µg/ml against at least one c. jejuni strain. seventeen plant extracts were ...201121604309
should immunocompromised patients have pets?to evaluate the risks and benefits of pet ownership by immunodeficient patients, focusing primarily on organisms that colonize animals and are transmitted to humans. those diseases that are known to be progressive or more severe in patients with altered immune function are emphasized.200821603465
selective quantification of viable eschericia coli in biosolids by quantitative pcr with propidium monoazide modification.quantitative differentiation of live cells in biosolids samples, without using culturing-based approaches, is highly critical from a public health risk perspective, as recent studies have shown significant re-growth and reactivation of indicator organisms. persistence of dna in the environment after cell death in the range of days to weeks limits the application of dna-based approaches as a measure of live cell density. using selective nucleic acid intercalating dyes like ethidium monoazide (ema ...201121602375
flagellar glycosylation in burkholderia pseudomallei and burkholderia thailandensis.glycosylation of proteins is known to impart novel physical properties and biological roles to proteins from both eukaryotes and prokaryotes. in this study, gel based glycoproteomics were used to identify glycoproteins of the potential bio-threat agent burkholderia pseudomallei and the closely related but non-pathogenic b. thailandensis. top-down and bottom-up ms analysis identified that the flagellin proteins of both species were post-translationally modified by novel glycans. analysis of prote ...201121602339
rapid identification and quantification of campylobacter coli and campylobacter jejuni by real-time pcr in pure cultures and in complex samples.abstract: background: campylobacter spp., especially campylobacter jejuni (c. jejuni) and campylobacter coli (c. coli), are recognized as the leading human foodborne pathogens in developed countries. livestock animals carrying campylobacter pose an important risk for human contamination. pigs are known to be frequently colonized with campylobacter, especially c. coli, and to excrete high numbers of this pathogen in their faeces. molecular tools, notably real-time pcr, provide an effective, rapid ...201121600037
metagenome of the gut of a malnourished child.abstract: background: malnutrition, a major health problem, affects a significant proportion of preschool children in developing countries. the devastating consequences of malnutrition include diarrhoea, malabsorption, increased intestinal permeability and suboptimal immune response etc. nutritional interventions and dietary solutions have not been effective for treatment of malnutrition till date. metagenomic procedures allow one to access the complex cross-talk between the gut and its microbia ...201121599906
the evolution of respiratory chain complex i from a smaller last common ancestor consisting of 11 protein subunits.the nadh:quinone oxidoreductase (complex i) has evolved from a combination of smaller functional building blocks. chloroplasts and cyanobacteria contain a complex i-like enzyme having only 11 subunits. this enzyme lacks the n-module which harbors the nadh binding site and the flavin and iron-sulfur cluster prosthetic groups. a complex i-homologous enzyme found in some archaea contains an f(420) dehydrogenase subunit denoted as fpof rather than the n-module. in the present study, all currently av ...201121597881
characterization of a dipartite iron-uptake system from uropathogenic escherichia coli strain f11.in the uropathogenic escherichia coli strain f11, in silico genome analysis revealed the novel dicistronic iron-uptake operon fetmp, which is under iron-regulated control mediated by the fur regulator. the expression of fetmp in a mutant strain lacking known iron-uptake systems improved growth under iron depletion and increased cellular iron accumulation. fetm is a member of the iron/lead transporter (ilt) superfamily and is essential for iron-uptake by the fet system. fetp is a periplasmic prot ...201121596746
ir and uv photodissociation as analytical tools for characterizing lipid a structures.the utility of 193-nm ultraviolet photodissociation (uvpd) and 10.6-μm infrared multiphoton dissociation (irmpd) for the characterization of lipid a structures was assessed in an ion trap mass spectrometer. the fragmentation behavior of lipid a species was also evaluated by activated-electron photodetachment (a-epd), which uses 193-nm photons to create charge reduced radicals that are subsequently dissociated by collisional activation. in contrast to collision-induced dissociation (cid), irmpd o ...201121595441
transmission and dose-response experiments for social animals: a reappraisal of the colonization biology of campylobacter jejuni in chickens.dose-response experiments characterize the relationship between infectious agents and their hosts. these experiments are routinely used to estimate the minimum effective infectious dose for an infectious agent, which is most commonly characterized by the dose at which 50 per cent of challenged hosts become infected-the id(50). in turn, the id(50) is often used to compare between different agents and quantify the effect of treatment regimes. the statistical analysis of dose-response data typicall ...201121593028
chemoenzymatic synthesis of c8-modified sialic acids and related α2-3- and α2-6-linked sialosides.naturally occurring 8-o-methylated sialic acids, including 8-o-methyl-n-acetylneuraminic acid and 8-o-methyl-n-glycolylneuraminic acid, along with 8-o-methyl-2-keto-3-deoxy-d-glycero-d-galacto-nonulosonic acid (kdn8me) and 8-deoxy-kdn were synthesized from corresponding 5-o-modified six-carbon monosaccharides and pyruvate using a sialic acid aldolase cloned from pasteurella multocida strain p-1059 (pmnana). in addition, α2-3- and α2-6-linked sialyltrisaccharides containing neu5ac8me and kdn8deox ...201121592790
transcriptome analysis of neisseria meningitidis in human whole blood and mutagenesis studies identify virulence factors involved in blood survival.during infection neisseria meningitidis (nm) encounters multiple environments within the host, which makes rapid adaptation a crucial factor for meningococcal survival. despite the importance of invasion into the bloodstream in the meningococcal disease process, little is known about how nm adapts to permit survival and growth in blood. to address this, we performed a time-course transcriptome analysis using an ex vivo model of human whole blood infection. we observed that nm alters the expressi ...201121589640
estimating background rates of guillain-barre syndrome in ontario in order to respond to safety concerns during pandemic h1n1/09 immunization campaign.abstract: background: the province of ontario, canada initiated mass immunization clinics with adjuvanted pandemic h1n1 influenza vaccine in october 2009. due to the campaign's scale, temporal associations with guillain-barre syndrome (gbs) and vaccination were expected. the objectives of this analysis were to estimate the number of background gbs cases expected to occur in the projected vaccinated population and to estimate the number of additional gbs cases which would be expected if an associ ...201121586163
chronic diarrhea associated with persistent norovirus excretion in patients with chronic lymphocytic leukemia: report of two cases.abstract: background: chronic diarrhea in patients treated with immunosuppressive agents or suffering from immunosuppressive disease can represent a diagnostic and therapeutic challenge to the clinician. norovirus infection, a major cause of acute epidemic diarrhea, has been described as a cause of chronic diarrhea in patients who are immunosuppressed, including transplant recipients and the very young. case presentations we describe two patients, a 64 year-old man and a 59 year-old woman, both ...201121586142
livestock and global change special feature: current drivers and future directions of global livestock disease dynamics.we review the global dynamics of livestock disease over the last two decades. our imperfect ability to detect and report disease hinders assessment of trends, but we suggest that, although endemic diseases continue their historic decline in wealthy countries, poor countries experience static or deteriorating animal health and epidemic diseases show both regression and expansion. at a mesolevel, disease is changing in terms of space and host, which is illustrated by bluetongue, lyme disease, and ...201121576468
livestock and global change special feature: current drivers and future directions of global livestock disease dynamics.we review the global dynamics of livestock disease over the last two decades. our imperfect ability to detect and report disease hinders assessment of trends, but we suggest that, although endemic diseases continue their historic decline in wealthy countries, poor countries experience static or deteriorating animal health and epidemic diseases show both regression and expansion. at a mesolevel, disease is changing in terms of space and host, which is illustrated by bluetongue, lyme disease, and ...201121576468
complete genome sequence of the marine fish pathogen vibrio anguillarum harboring the pjm1 virulence plasmid and genomic comparison with other virulent strains of v. anguillarum and v. ordalii.we dissected the complete genome sequence of the o1 serotype v. anguillarum 775 (pjm1), and determined the draft genomic sequences of the plasmidless strains of serotype o1, 96f and o2β, rv22 and v. ordalii. all strains harbor two chromosomes but 775 also carries the virulence plasmid pjm1 that encodes the genes to produce anguibactin and cognate transport genes, one of the main virulence factors of v. anguillarum. genomic analysis identified eight genomic islands in chromosome 1 of v. anguillar ...201121576332
[construction of chea insertion mutant of campylobacter jejuni and the effect of its adhesion on mice jejunum].to construct chea (chemotaxis, che) insertion mutant of campylobacter jejuni and to observe the role of chea gene in adhesion of campylobacter jejuni on mice jejunum.201121574382
crystal structure of the bifunctional trna modification enzyme mnmc from escherichia coli.post-transcriptional modifications of bases within the transfer rnas (trna) anticodon significantly affect the decoding system. in bacteria and eukaryotes, uridines at the wobble position (u34) of some trnas are modified to 5-methyluridine derivatives (xm(5) u). these xm(5) u34-containing trnas read codons ending with a or g, whereas trnas with the unmodified u34 are able to read all four synonymous codons of a family box. in escherichia coli (e.coli), the bifunctional enzyme mnmc catalyzes the ...201121574198
the rna chaperone hfq is important for growth and stress tolerance in francisella novicida.the rna-binding protein hfq is recognized as an important regulatory factor in a variety of cellular processes, including stress resistance and pathogenesis. hfq has been shown in several bacteria to interact with small regulatory rnas and act as a post-transcriptional regulator of mrna stability and translation. here we examined the impact of hfq on growth, stress tolerance, and gene expression in the intracellular pathogen francisella novicida. we present evidence of hfq involvement in the abi ...201121573133
population dynamics of salmonella enterica serotypes in commercial egg and poultry production.fresh and processed poultry have been frequently implicated in cases of human salmonellosis. furthermore, increased consumption of meat and poultry has increased the potential for exposure to salmonella. while advances have been made in reducing the prevalence and frequency of salmonella contamination in processed poultry, there is mounting pressure on commercial growers to prevent and/or eliminate these human pathogens in preharvest production facilities. several factors contribute to salmonell ...201121571882
survival of campylobacter jejuni on beef and pork under vacuum packaged and retail storage conditions: examination of the role of natural meat microflora on c. jejuni survival.the ability of campylobacter jejuni atcc 11168 to survive on beef and pork stored under chilled, vacuum packaged and retail display conditions were examined. in addition, the effect of natural microflora on commercial beef and pork on the survival of c. jejuni under these storage conditions was examined. when sterile cores of beef and pork were inoculated with ∼10(5) to 10(6) cfu cm(-2)c. jejuni, and were stored under aerobic or vacuum packaged conditions at -1.5 or 4 °c, its numbers dropped sig ...201121569945
influence of cell surface hydrophobicity on attachment of campylobacter to abiotic surfaces.this work aimed to investigate the influence of physicochemical properties and prior mode of growth (planktonic or sessile culture) on attachment of 13 campylobacter jejuni strains and 5 campylobacter coli strains isolated from chicken samples to three abiotic surfaces: stainless steel, glass and polyurethane. water contact angle and zeta potential measurements indicated that the strains varied with respect to surface hydrophobicity (17.6 ± 1.5 to 53.0 ± 2.3°) and surface charge (-3.3 ± 0.4 to - ...201121569937
campylobacter contamination of broiler caeca and carcasses at the slaughterhouse and correlation with salmonella contamination.in order to estimate the prevalence of campylobacter spp. and salmonella spp. on broiler chicken carcasses and the prevalence of campylobacter spp. in caeca, 58 french slaughterhouses were investigated in 2008. enumeration of campylobacter spp. was also performed in order to study the relation between caeca and carcass contamination. a pool of 10 caeca and one carcass were collected from 425 different batches over a 12-month period in 2008. salmonella was isolated on 32 carcasses leading to a pr ...201121569927
strain engineering for improved expression of recombinant proteins in bacteria.abstract: protein expression in escherichia coli represents the most facile approach for the preparation of non-glycosylated proteins for analytical and preparative purposes. so far, the optimization of recombinant expression has largely remained a matter of trial and error and has relied upon varying parameters, such as expression vector, media composition, growth temperature and chaperone co-expression. recently several new approaches for the genome-scale engineering of e. coli to enhance reco ...201121569582
stimulation of growth of the human gastric pathogen helicobacter pylori by atmospheric level of oxygen under high carbon dioxide tension.abstract: background: helicobacter pylori (hp), a human pathogen that is associated with gastritis, peptic ulcer, and gastric cancer, has been considered a microaerophile, but there is no general consensus about its specific o2 requirements. a clear understanding of hp physiology is needed to elucidate the pathogenic mechanism(s) of hp infection. results: we cultured hp under a range of o2 levels with or without 10% co2 and evaluated growth profiles, morphology, intracellular ph, and energy meta ...201121569333
cytolethal distending toxin: a conserved bacterial genotoxin that blocks cell cycle progression, leading to apoptosis of a broad range of mammalian cell lineages.cytolethal distending toxin (cdt) is a heterotrimeric ab-type genotoxin produced by several clinically important gram-negative mucocutaneous bacterial pathogens. irrespective of the bacterial species of origin, cdt causes characteristic and irreversible cell cycle arrest and apoptosis in a broad range of cultured mammalian cell lineages. the active subunit cdtb has structural homology with the phosphodiesterase family of enzymes including mammalian dnase i, and alone is necessary and sufficient ...201121565933
lectin typing of campylobacter jejuni using a novel quartz crystal microbalance technique.seven campylobacter jejuni strains were characterised by a lectin typing assay. the typing system was based on a quartz crystal microbalance technique (qcm) with four commercially available lectins (wheat germ agglutinin, maackia amurensis lectin, lens culinaris agglutinin, and concanavalin a), which were chosen for their differing carbohydrate specificities. initially, the gold surfaces of the quartz crystals were modified with 11-mercaptoundecanoic acid followed by lectin immobilisation using ...201121565296
bacterial peptides are intensively present throughout the human proteome.forty bacterial proteomes-20 pathogens and 20 non-pathogens-were examined for amino acid sequence similarity to the human proteome. all bacterial proteomes, independent of their pathogenicity, share hundreds of nonamer sequences with the human proteome. this overlap is very widespread, with one third of human proteins sharing at least one nonapeptide with one of these bacteria. on the whole, the bacteria-versus-human nonamer overlap is numerically defined by 47,610 total perfect matches dissemin ...201021559180
dual enlargement of gold nanoparticles: from mechanism to scanometric detection of pathogenic bacteria.a mechanism of dual enlargement of gold nanoparticles (aunps) comprising two steps is described. in the first step, the aunps are enlarged by depositing au atoms on their crystalline faces. in this process, the particles are not only enlarged but they are also observed to multiply: new au nuclei are formed by the budding and division of the enlarged particles. in the second step, a silver enhancement is subsequently performed by the deposition of silver atoms on the enlarged and newly formed aun ...201121557470
structural and enzymatic characterization of nans (yjhs), a 9-o-acetyl n-acetylneuraminic acid esterase from escherichia coli o157:h7.there is a high prevalence of sialic acid in a number of different organisms, resulting in there being a myriad of different enzymes that can exploit it as a fermentable carbon source. one such enzyme is nans, a carbohydrate esterase that we show here deacetylates the 9 position of 9-o-sialic acid so that it can be readily transported into the cell for catabolism. through structural studies, we show that nans adopts a sgnh hydrolase fold. although the backbone of the structure is similar to prev ...201121557376
acute encephalopathy associated with campylobacter jejuni enteritis.we present for the first time a case of acute encephalopathy in an adult patient induced by campylobacter jejuni enteritis. possible pathogenic mechanisms and importance of neuropsychological testing in the assessment of infection-related encephalopathy are discussed.201121556865
biochemical characterization of the o-linked glycosylation pathway in neisseria gonorrhoeae responsible for biosynthesis of protein glycans containing n,n'-diacetylbacillosamine.the o-linked protein glycosylation pathway in neisseria gonorrhoeae is responsible for the synthesis of a complex oligosaccharide on undecaprenyl diphosphate and subsequent en bloc transfer of the glycan to serine residues of select periplasmic proteins. protein glycosylation (pgl) genes have been annotated on the basis of bioinformatics and top-down mass spectrometry analysis of protein modifications in pgl-null strains [aas, f. e., et al. (2007) mol. microbiol. 65, 607-624; vik, a., et al. (20 ...201121542610
may ingestion of leachate from decomposed corpses cause appendicitis? a case report.the general consensus is that appendicitis is basically provoked by fecaliths or lymphoid hyperplasic obstruction. several studies based on histological diagnosis have not confirmed this hypothesis. on the contrary, obstruction has been proved in only a minority of cases. diverse infections by parasites, bacteria, fungus, and noninfective agents have been associated with appendicitis in the medical literature. we describe a firefighter, who ingested a small quantity of leachate from decomposing ...201121541232
genomic comparison of invasive and rare non-invasive strains reveals porphyromonas gingivalis genetic polymorphisms.porphyromonas gingivalis strains are shown to invade human cells in vitro with different invasion efficiencies, varying by up to three orders of magnitude.201121541093
antimicrobial edible apple films inactivate antibiotic resistant and susceptible campylobacter jejuni strains on chicken breast.campylobacter jejuni is the leading cause of bacterial diarrheal illness worldwide. many strains are now becoming multidrug resistant. apple-based edible films containing carvacrol and cinnamaldehyde were evaluated for bactericidal activity against antibiotic resistant and susceptible c. jejuni strains on chicken. retail chicken breast samples inoculated with d28a and h2a (resistant strains) and a24a (a sensitive strain) were wrapped in apple films containing cinnamaldehyde or carvacrol at 0.5%, ...201121535839
effect of refrigerated and frozen storage on the survival of campylobacter jejuni in cooked chicken meat breast.this experimental work aimed to examine the survivability of campylobacter jejuni in cooked chicken breast under several conditions: storage for 1, 3, and 7 d at refrigerated temperatures (4 °c) and for 20 d at frozen temperatures (-18 °c). in addition, storage at ambient temperature (26 to 28 °c) was involved. chicken samples were inoculated with a mixed culture of c. jejuni strains (atcc: 29428 and 33219) of known concentrations (50 and 500 cfu/g). bacterial cells were recovered and enumerated ...201121535688
prevalence and characterization of campylobacter jejuni isolated from pasture flock poultry.the growing interest in organic and natural foods warrants a greater need for information on the food safety of these products. in this study, samples were taken from 2 pasture flock farms (n= 178; feed, water, drag swabs, and insect traps), pasture flock retail carcasses (n= 48) and 1 pasture flock processing facility (n= 16) over a period of 8 mo. a total of 105 campylobacter isolates were obtained from 53 (30%), 36 (75%), and 16 (100%) samples from the farms, retail carcasses, and processing ...201021535562
a missing enzyme in thiamin thiazole biosynthesis: identification of teni as a thiazole tautomerase.in many bacteria teni is found clustered with genes involved in thiamin thiazole biosynthesis. however, while teni shows high sequence similarity with thiamin phosphate synthase, the purified protein has no thiamin phosphate synthase activity, and the role of this enzyme in thiamin biosynthesis remains unknown. in this contribution, we identify the function of teni as a thiazole tautomerase, describe the structure of the enzyme complexed with its reaction product, identify the substrates phospha ...201121534620
clinical significance of erythromycin-resistant campylobacter jejuni in children.campylobacter has been recognized as the common cause of bacterial gastroenteritis in many countries. increasing erythromycin resistance in campylobacter jejuni infection is noted recently, but severe case was rarely reported. in this study, we aimed to clarify the clinical significance of the resistant strain of c jejuni in children. we reviewed the charts of children who were diagnosed with c jejuni enteritis in our hospital from january 2000 to december 2005, including 326 patients (117 males ...201121531355
antimicrobial susceptibility in thermophilic campylobacter species isolated from pigs and chickens in south africa.campylobacter jejuni is one of the leading causes of sporadic food-borne bacterial disease in humans. in intensive poultry and pig rearing systems the use of oral antibiotics is essential to maintain health. consequently, there is a high risk for the thermophilic campylobacter jejuni and c. coli resident in the intestinal tract of food animals to develop resistance to commonly used antibiotics. contamination of meat or eggs with pathogenic strains of resistant campylobacter could, therefore, res ...201021526738
evolutionary forces shaping the golgi glycosylation machinery: why cell surface glycans are universal to living cells.despite more than 3 billion years since the origin of life on earth, the powerful forces of biological evolution seem to have failed to generate any living cell that is devoid of a dense and complex array of cell surface glycans. thus, cell surface glycans seem to be as essential for life as having a dna genetic code, diverse rnas, structural/functional proteins, lipid-based membranes, and metabolites that mediate energy flux and signaling. the likely reasons for this apparently universal law of ...201121525513
the virulence factor peb4 and the periplasmic protein cj1289 are two structurally related sura-like chaperones in the human pathogen campylobacter jejuni.the peb4 protein is an antigenic virulence factor implicated in host cell adhesion, invasion and colonisation in the food-borne pathogen campylobacter jejuni. peb4 mutants have defects in outer membrane protein (omp) assembly and peb4 is thought to act as a periplasmic chaperone. the crystallographic structure of peb4 at 2.2å resolution reveals a dimer with distinct sura-like chaperone and peptidyl prolyl cis/transisomerase (ppiase) domains encasing a large central cavity. unlike sura, the chape ...201121524997
differentiation of campylobacter species by surface-enhanced laser desorption/ionization-time-of-flight mass spectrometry.abstract the genus campylobacter contains several, widespread pathogens causing food-borne diseases of zoonotic nature in humans. in case of outbreaks, the differentiation of closely related campylobacter is essential for epidemiological studies, which investigate the routes of geographical spread and ways of transmission. recent advances in mass spectrometry (ms) have shown that matrix-assisted laser desorption/ionization-time-of-flight (maldi-tof) ms is a valuable tool for speciation of bacter ...201121524195
aptamer in bioanalytical applications. 201121524128
bovine antibody-based oral immunotherapy for reduction of intragastric helicobacter pylori colonization: a randomized clinical trial.antibiotic-based regimens are frequently used for the treatment of helicobacter pylori infection. these regimens fail to eradicate h pylori in 15% to 40% of patients, primarily due to antimicrobial resistance and insufficient patient compliance. effective prevention and eradication of h pylori by passive immunization with orally administered bovine antibodies has been demonstrated in animal studies, and may serve as an alternative therapy in humans.201121523262
bioinformatic characterization of the trimeric intracellular cation-specific channel protein family.trimeric intracellular cation-specific (tric) channels are integral to muscle excitation-contraction coupling. tric channels provide counter-ionic flux when calcium is rapidly transported from intracellular stores to the cell cytoplasm. until recently, knowledge of the presence of these proteins was limited to animals. we analyzed the tric family and identified a profusion of prokaryotic family members with topologies and motifs similar to those of their eukaryotic counterparts. prokaryotic memb ...201121519847
preventing antibiotic resistance: the next step.there is universal agreement that the emergence of antibiotic-resistant bacteria is a significant health problem, leading to preventable morbidity and mortality. kaiser permanente (kp) has made great strides in improving the antibiotic-prescribing behavior of its physicians, thereby limiting the emergence of antibiotic resistance in the clinical setting. this, however, is only a beginning. greater than 70% of the antibiotics used in the united states are for nontherapeutic purposes in animal fee ...200621519468
real-time pcr analysis of enteric pathogens from fecal samples of irritable bowel syndrome subjects.abstract: background: growing amount of scientific evidence suggests that microbes are involved in the pathophysiology of irritable bowel syndrome (ibs). the predominant fecal microbiota composition of ibs subjects has been widely studied with dna-based techniques but less research has been focused on the intestinal pathogens in this disorder. here, we optimized a highly sensitive panel of 12 quantitative real-time pcr (qpcr) assays to shed light on the putative presence of intestinal pathogens ...201121518462
the antibiotic potential of prokaryotic imp dehydrogenase inhibitors.inosine 5'-monophosphate dehydrogenase (impdh) catalyzes the first committed step of guanosine 5'-monophosphate (gmp) biosynthesis, and thus regulates the guanine nucleotide pool, which in turn governs proliferation. human impdhs are validated targets for immunosuppressive, antiviral and anticancer drugs, but as yet microbial impdhs have not been exploited in antimicrobial chemotherapy. selective inhibitors of impdh from cryptosporidium parvum have recently been discovered that display anti-para ...201121517780
preceding infections and anti-ganglioside antibody profiles assessed by a dot immunoassay in 306 french guillain-barré syndrome patients.we describe by an in-house dot immunoassay, specific anti-ganglioside and sulfatide antibodies, by comparing the results from a large group of 134 infected french gbs patients and those from 172 noninfected french gbs and 142 control groups. a recent infection was identified in 134/306 (43.8%) gbs patients: campylobacter jejuni (24.6%) was the most common agent, followed by cytomegalovirus (12.4%), mycoplasma pneumoniae (3.2%) and epstein-barr virus (1.3%). anti-ganglioside antibodies were detec ...201121516465
pmst2 - a novel pasteurella multocida glycolipid {alpha}2-3-sialyltransferase.pasteurella multocida is a multi-species pathogen that causes diseases in animals and humans. sialyltransferase activity has been detected in multiple pasteurella multocida strains and sialylation has been shown to be important for the pathogenesis of pasteurella multocida. three putative sialyltransferase genes have been identified in pasteurella multocida genomic strain pm70. we have reported previously that a pm0188 gene homolog in p. multocida strain p-1059 (atcc 15742) encodes a multifuncti ...201121515586
evaluation of low-copy genetic targets for waterborne bacterial pathogen detection via qpcr.recent developments in water quality research have highlighted difficulties in accurately predicting the incidence of pathogens within freshwater based on the viability, culturability and metabolic activity of indicator organisms. qpcr-driven assays are candidates to replace standard culture-based methods, however, protocols suitable for routine use have yet to be sufficiently validated. the objective of this study was to evaluate five oligonucleotide primers sets (etir, sinv, exot, vs1 and ipah ...201121514618
prevalence and risk factors for campylobacter spp. in chicken broiler flocks in reunion island (indian ocean).our objectives were to determine campylobacter prevalence in broiler chicken flocks in reunion island and to define specific practices associated with the presence of campylobacter spp. infection in reunionese broiler flocks. fifty broiler flocks were studied in reunion island from may 2007 to february 2009. a questionnaire was submitted to the farmers and samples of fresh droppings were collected to assess the flock's campylobacter status. fifty four percent of the flocks were infected by campy ...201121511349
the expanding horizons of asparagine-linked glycosylation.asparagine-linked glycosylation involves the sequential assembly of an oligosaccharide onto a polyisoprenyl donor, followed by the en bloc transfer of the glycan to particular asparagine residues within acceptor proteins. these n-linked glycans play a critical role in a wide variety of biological processes, such as protein folding, cellular targeting and motility, and the immune response. in the past decade, research in the field of n-linked glycosylation has achieved major advances, including t ...201121506607
quantification of acid-base interactions based on contact angle measurement allows xdlvo predictions to attachment of campylobacter jejuni but not salmonella.acid-base (ab) interactions play the most important role in bacterial attachment to surfaces and can be quantified based on electron donor/electron acceptor data from contact angle measurement (cam) according to the extended derjaguin-landau-verwey-overbeek (xdlvo) theory. it follows that the xdlvo theory could fail to explain attachment numbers if differences in ab interactions between strains are not apparent by cam. this study aimed to investigate the validity of the above assumptions by comp ...201121504764
the human postsynaptic density shares conserved elements with proteomes of unicellular eukaryotes and prokaryotes.the animal nervous system processes information from the environment and mediates learning and memory using molecular signaling pathways in the postsynaptic terminal of synapses. postsynaptic neurotransmitter receptors assemble to form multiprotein complexes that drive signal transduction pathways to downstream cell biological processes. studies of mouse and drosophila postsynaptic proteins have identified key roles in synaptic physiology and behavior for a wide range of proteins including recep ...201121503141
campylobacter jejuni lipo-oligosaccharides modulate dc-mediated t cell polarization in a sialic acid linkage dependent manner.carbohydrate mimicry between campylobacter jejuni lipo-oligosaccharides (los) and host neural gangliosides plays a crucial role in the pathogenesis of guillain-barré syndrome (gbs). campylobacter jejuni los may mimic various gangliosides, which affects the immunogenicity and the type of neurological deficits in gbs patients. previous studies have shown the interaction of los with sialic acid-specific siglec receptors, although the functional consequences remain unknown. cells that express high l ...201121502591
site-specific enzymatic polysialylation of therapeutic proteins using bacterial enzymes.the posttranslational modification of therapeutic proteins with terminal sialic acids is one means of improving their circulating half-life, thereby improving their efficiency. we have developed a two-step in vitro enzymatic modification of glycoproteins, which has previously only been achieved by chemical means [gregoriadis g, jain s, papaioannou i, laing p (2005) int j pharm 300:125-130). this two-step procedure uses the campylobacter jejuni cst-ii α2,8-sialyltransferase to provide a primer on ...201121502532
campylobacter jejuni, campylobacter coli, and cytolethal distending toxin genes in laying hens.as no data are available on the prevalence of cytolethal distending toxin (cdt) genes carried by campylobacter spp. in laying hens, this study was conducted with the aim to evaluate the prevalence of both campylobacter spp. and cdt genes in 1680 laying hens from four different farms. the samples were analyzed by culture methods and by polymerase chain reaction. campylobacter spp. were isolated from 1097/1680 cloacal swabs. among the isolates, 913 were identified as campylobacter jejuni whereas 3 ...201121500644
harvesting the biological potential of the human gut microbiome. 201121500237
occurrence of thermotolerant campylobacter spp. on eggshells: a missing link for food-borne infections?we analyzed the prevalence of thermotolerant campylobacter spp. compared that of to salmonella spp. in raw yolk and on eggshells. a total of 2,710 eggs were investigated for each bacterium. viable bacteria were found in 4.1% (campylobacter spp.) and 1.1% (salmonella spp.) of the eggshell samples, whereas the egg yolk samples were negative for both bacteria.201121498761
rapid detection of viable salmonella in produce by coupling propidium monoazide with loop-mediated isothermal amplification (pma-lamp).recent outbreaks linked to salmonella-contaminated produce heightened the need to develop simple, rapid, and accurate detection methods, particularly those capable of determining cell viability. in this study, we examined a novel strategy for the rapid detection and quantification of viable salmonella in produce by coupling a simple propidium monoazide sample treatment with loop-mediated isothermal amplification (pma-lamp). we first designed and optimized a lamp assay targeting salmonella. secon ...201121498750
tungsten and molybdenum regulation of formate dehydrogenase expression in desulfovibrio vulgaris hildenborough.formate is an important energy substrate for sulfate-reducing bacteria in natural environments, and both molybdenum- and tungsten-containing formate dehydrogenases have been reported in these organisms. in this work, we studied the effect of both metals on the levels of the three formate dehydrogenases encoded in the genome of desulfovibrio vulgaris hildenborough, with lactate, formate, or hydrogen as electron donors. using western blot analysis, quantitative real-time pcr, activity-stained gels ...201121498650
ferritin structure from mycobacterium tuberculosis: comparative study with homologues identifies extended c-terminus involved in ferroxidase activity.ferritins are recognized as key players in the iron storage and detoxification processes. iron acquisition in the case of pathogenic bacteria has long been established as an important virulence mechanism. here, we report a 3.0 å crystal structure of a ferritin, annotated as bacterioferritin b (bfrb), from mycobacterium tuberculosis (mtb), the causative agent of tuberculosis that continues to be one of the world's deadliest diseases. similar to the other members of ferritin family, the mtb bfrb s ...201121494619
citrobacter rodentium is an unstable pathogen showing evidence of significant genomic flux.citrobacter rodentium is a natural mouse pathogen that causes attaching and effacing (a/e) lesions. it shares a common virulence strategy with the clinically significant human a/e pathogens enteropathogenic e. coli (epec) and enterohaemorrhagic e. coli (ehec) and is widely used to model this route of pathogenesis. we previously reported the complete genome sequence of c. rodentium icc168, where we found that the genome displayed many characteristics of a newly evolved pathogen. in this study, th ...201121490962
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