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cj1411c encodes for a cytochrome p450 involved in campylobacter jejuni 81-176 pathogenicity.cytochrome p450s are b-heme-containing enzymes that are able to introduce oxygen atoms into a wide variety of organic substrates. they are extremely widespread in nature having diverse functions at both biochemical and physiological level. the genome of c. jejuni 81-176 encodes a single cytochrome p450 (cj1411c) that has no close homologues. cj1411c is unusual in its genomic location within a cluster involved in the biosynthesis of outer surface structures. here we show that e. coli expressed an ...201324086558
biochemical analysis and structure determination of bacterial acetyltransferases responsible for the biosynthesis of udp-n,n'-diacetylbacillosamine.udp-n,n'-diacetylbacillosamine (udp-dinacbac) is a unique carbohydrate produced by a number of bacterial species and has been implicated in pathogenesis. the terminal step in the formation of this important bacterial sugar is catalyzed by an acetyl-coa (accoa)-dependent acetyltransferase in both n- and o-linked protein glycosylation pathways. this bacterial acetyltransferase is a member of the left-handed β-helix family and forms a homotrimer as the functional unit. whereas previous endeavors ha ...201324064219
from ambivalent to divalent: has the "zinc age" finally arrived? 201324061143
extracellular secretion of protease htra from campylobacter jejuni is highly efficient and independent of its protease activity and flagellum.the serine protease htra of c. jejuni has been identified as a novel secreted virulence factor which opens cell-to-cell junctions by cleaving e-cadherin. efficient c. jejuni transmigration across polarized human epithelial cells requires the intact flagellum and htra; however, the mechanism of htra secretion into the supernatant is unknown. here we show that htra secretion is highly efficient and does not require its proteolytic activity because the protease-inactive s197a mutant is secreted lik ...201324265934
survey of extra-intestinal immune responses in asymptomatic long-term campylobacter jejuni-infected mice.campylobacter jejuni is among the most frequently reported bacterial pathogens causing diarrhea in humans worldwide. we recently reported a murine infection model mimicking key features of human campylobacteriosis. six days following oral c. jejuni infection immediately after weaning, infant mice developed acute enterocolitis resolving within 2 weeks. thereafter, c. jejuni could still be isolated from the intestines of asymptomatic mice at low levels accompanied by distinct immune responses, bot ...201324265935
eukaryotic oligosaccharyltransferase generates free oligosaccharides during n-glycosylation.asparagine (n)-linked glycosylation regulates numerous cellular activities, such as glycoprotein quality control, intracellular trafficking, and cell-cell communications. in eukaryotes, the glycosylation reaction is catalyzed by oligosaccharyltransferase (ost), a multimembrane protein complex that is localized in the endoplasmic reticulum (er). during n-glycosylation in the er, the protein-unbound form of oligosaccharides (free oligosaccharides; foss), which is structurally related to n-glycan, ...201324062310
genetically dictated change in host mucus carbohydrate landscape exerts a diet-dependent effect on the gut microbiota.we investigate how host mucus glycan composition interacts with dietary carbohydrate content to influence the composition and expressed functions of a human gut community. the humanized gnotobiotic mice mimic humans with a nonsecretor phenotype due to knockout of their α1-2 fucosyltransferase (fut2) gene. the fecal microbiota of fut2(-) mice that lack fucosylated host glycans show decreased alpha diversity relative to fut2(+) mice and exhibit significant differences in community composition. a g ...201324062455
the prevalence and polymorphisms of zonula occluden toxin gene in multiple campylobacter concisus strains isolated from saliva of patients with inflammatory bowel disease and controls.campylobacterconcisus is an oral bacterium. a number of studies detected a significantly higher prevalence of c. concisus in the intestinal tract of patients with inflammatory bowel disease (ibd) as compared to controls. the prevalence of zonula occluden toxin (zot) gene, which encodes a toxin known to increase intestinal permeability, in oral c. concisus strains is unknown. increased intestinal permeability is a feature of ibd. a total of 56 oral c. concisus strains isolated from 19 patients wi ...201324086553
degeneration of a crispr/cas system and its regulatory target during the evolution of a pathogen.crispr/cas systems are bacterial rna-guided endonuclease machineries that target foreign nucleic acids. recently, we demonstrated that the cas protein cas9 controls gene expression and virulence in francisella novicida by altering the stability of the mrna for an immunostimulatory bacterial lipoprotein (blp). genomic analyses, however, revealed that francisella species with increased virulence harbor degenerated crispr/cas systems. we hypothesize that crispr/cas degeneration removed a barrier ag ...201324100224
concurrent automated sequencing of the glycan and peptide portions of o-linked glycopeptide anions by ultraviolet photodissociation mass spectrometry.o-glycopeptides are often acidic owing to the frequent occurrence of acidic saccharides in the glycan, rendering traditional proteomic workflows that rely on positive mode tandem mass spectrometry (ms/ms) less effective. in this report, we demonstrate the utility of negative mode ultraviolet photodissociation (uvpd) ms for the characterization of acidic o-linked glycopeptide anions. this method was evaluated for a series of singly and multiply deprotonated glycopeptides from the model glycoprote ...201324006841
population genetics of lactobacillus sakei reveals three lineages with distinct evolutionary histories.lactobacillus sakei plays a major role in meat fermentation and in the preservation of fresh meat. the large diversity of l. sakei strains represents a valuable and exploitable asset in the development of a variety of industrial applications; however, an efficient method to identify and classify these strains has yet to be developed. in this study, we used multilocus sequence typing (mlst) to analyze the polymorphism and allelic distribution of eight loci within an l. sakei population of 232 str ...201324069179
therapeutic targeting of nod1 receptors.the nucleotide-binding oligomerization domain 1 (nod1) protein is an intracellular receptor for breakdown products of peptidoglycan (pgn), an essential bacterial cell wall component. nod1 responds to γ-d-glutamyl-meso-diaminopimelic acid, which is an epitope unique to pgn structures from all gram-negative bacteria and certain gram-positive bacteria. upon ligand recognition, nod1 undergoes conformational changes and self-oligomerization mediated by the nucleotide-binding nacht domains, followed b ...201323848281
strategy for sensitive and specific detection of yersinia pestis in skeletons of the black death pandemic.yersinia pestis has been identified as the causative agent of the black death pandemic in the 14(th) century. however, retrospective diagnostics in human skeletons after more than 600 years are critical. we describe a strategy following a modern diagnostic algorithm and working under strict ancient dna regime for the identification of medieval human plague victims. an initial screening and dna quantification assay detected the y. pestis specific pla gene of the high copy number plasmid ppcp1. re ...201324069445
campylobacter jejuni colonization is associated with a dysbiosis in the cecal microbiota of mice in the absence of prominent inflammation.campylobacter jejuni causes enterocolitis in humans, but does not incite disease in asymptomatic carrier animals. to survive in the intestine, c. jejuni must successfully compete with the microbiota and overcome the host immune defense. campylobacter jejuni colonization success varies considerably amongst individual mice, and we examined the degree to which the intestinal microbiota was affected in mice (i.e. a model carrier animal) colonized by c. jejuni at high relative to low densities.201324066174
de- and repolarization mechanism of flagellar morphogenesis during a bacterial cell cycle.eukaryotic morphogenesis is seeded with the establishment and subsequent amplification of polarity cues at key times during the cell cycle, often using (cyclic) nucleotide signals. we discovered that flagellum de- and repolarization in the model prokaryote caulobacter crescentus is precisely orchestrated through at least three spatiotemporal mechanisms integrated at tipf. we show that tipf is a cell cycle-regulated receptor for the second messenger--bis-(3'-5')-cyclic dimeric guanosine monophosp ...201324065770
the opportunistic pathogen propionibacterium acnes: insights into typing, human disease, clonal diversification and camp factor evolution.we previously described a multilocus sequence typing (mlst) scheme based on eight genes that facilitates population genetic and evolutionary analysis of p. acnes. while mlst is a portable method for unambiguous typing of bacteria, it is expensive and labour intensive. against this background, we now describe a refined version of this scheme based on two housekeeping (aroe; guaa) and two putative virulence (tly; camp2) genes (mlst4) that correctly predicted the phylogroup (ia1, ia2, ib, ic, ii, i ...201324058439
parallel evolution of genome structure and transcriptional landscape in the epsilonproteobacteria.gene reshuffling, point mutations and horizontal gene transfer contribute to bacterial genome variation, but require the genome to rewire its transcriptional circuitry to ensure that inserted, mutated or reshuffled genes are transcribed at appropriate levels. the genomes of epsilonproteobacteria display very low synteny, due to high levels of reshuffling and reorganisation of gene order, but still share a significant number of gene orthologs allowing comparison. here we present the primary trans ...201324028687
phage display-derived binders able to distinguish listeria monocytogenes from other listeria species.the objective of this study was to produce phage display-derived binders with the ability to distinguish listeria monocytogenes from other listeria spp., which may have potential utility to enhance detection of listeria monocytogenes. to obtain binders with the desired binding specificity a series of surface and solution phage-display biopannings were performed. initially, three rounds of surface biopanning against gamma-irradiated l. monocytogenes serovar 4b cells were performed followed by an ...201324040227
deprivation, timing of preschool infections and h. pylori seropositivity at age 49-51 years: the newcastle thousand families birth cohort.helicobacter pylori infection is acquired in early childhood and persists for life (or until eradication treatment is taken). seropositivity of h. pylori at age 49-51 years was assessed in relation to socio-economic deprivation in early life and the timing of other childhood infections common at that time.201324010891
multilocus sequence typing (and phylogenetic analysis) of campylobacter jejuni and campylobacter coli strains isolated from clinical cases in greece.the molecular epidemiology of c. jejuni and c. coli clinical strains isolated from children with gastroenteritis, was investigated using the multilocus sequence typing method (mlst). this analysis establishes for the first time in greece and constitutes an important tool for the epidemiological surveillance and control of campylobacter infection in our country.201324010733
enterohemorrhagic escherichia coli as causes of hemolytic uremic syndrome in the czech republic.enterohemorrhagic escherichia coli (ehec) cause diarrhea-associated hemolytic uremic syndrome (d+ hus) worldwide, but no systematic study of ehec as the causative agents of hus was performed in the czech republic. we analyzed stools of all patients with d+ hus in the czech republic between 1998 and 2012 for evidence of ehec infection. we determined virulence profiles, phenotypes, antimicrobial susceptibilities and phylogeny of the ehec isolates.201324040117
metabolism, physiological role, and clinical implications of sphingolipids in gastrointestinal tract.sphingolipids in digestive system are responsible for numerous important physiological and pathological processes. in the membrane of gut epithelial cells, sphingolipids provide structural integrity, regulate absorption of some nutrients, and act as receptors for many microbial antigens and their toxins. moreover, bioactive sphingolipids such as ceramide or sphingosine-1-phosphate regulate cellular growth, differentiation, and programmed cell death-apoptosis. although it is well established that ...201324083248
sociocultural determinants of anticipated vaccine acceptance for acute watery diarrhea in early childhood in katanga province, democratic republic of congo.rotavirus and oral cholera vaccines have the potential to reduce diarrhea-related child mortality in low-income settings and are recommended by the world health organization. uptake of vaccination depends on community support, and is based on local priorities. this study investigates local perceptions of acute watery diarrhea in childhood and anticipated vaccine acceptance in two sites in the democratic republic of congo. in 2010, 360 randomly selected non-affected adults were interviewed by usi ...201323878187
a structural comparison of lipopolysaccharide biosynthesis loci of legionella pneumophila serogroup 1 strains.the lipopolysaccharide (lps) is the major immuno-dominant antigen of all legionella species including l. pneumophila. its diversity is the basis for the classification of l. pneumophila into serogroups and monoclonal subgroups and is thought to be involved in strain specific virulence. the understanding of the genetic basis of the lps-antigen is incomplete. thus, we analyzed the genetic locus involved in lps-biosynthesis of l. pneumophila serogroup 1 (sg1) strains with the focus on strain specif ...201324069939
diet, microbial virulence, and helicobacter pylori-induced gastric cancer.gastric adenocarcinoma is a leading cause of cancer-related death worldwide, and helicobacter pylori infection is one of the strongest known risk factors for this malignancy. h. pylori strains exhibit a high level of genetic diversity, and the risk of gastric cancer is higher in persons carrying certain strain types (for example, those that contain a cag pathogenicity island or type s1 vaca alleles) than in persons carrying other strain types. additional risk factors for gastric cancer include s ...201323989802
a regulatory checkpoint during flagellar biogenesis in campylobacter jejuni initiates signal transduction to activate transcription of flagellar genes.many polarly flagellated bacteria require similar two-component regulatory systems (tcss) and σ(54) to activate transcription of genes essential for flagellar motility. herein, we discovered that in addition to the flagellar type iii secretion system (t3ss), the campylobacter jejuni flagellar ms ring and rotor are required to activate the flgsr tcs. mutants lacking the flif ms ring and flig c ring rotor proteins were as defective as t3ss mutants in flgsr- and σ(54)-dependent flagellar gene expre ...201324003178
food safety in home kitchens: a synthesis of the literature.although foodborne illness is preventable, more than 56,000 people per year become ill in the u.s., creating high economic costs, loss of productivity and reduced quality of life for many. experts agree that the home is the primary location where foodborne outbreaks occur; however, many consumers do not believe the home to be a risky place. health care professionals need to be aware of consumers' food safety attitudes and behaviors in the home and deliver tailored food safety interventions that ...201324002725
a rare form of guillan barre syndrome: a child diagnosed with anti-gd1a and anti-gd1b positive pharyngeal-cervical-brachial variant.pharyngeal-cervical-brachial (pcb) variant is a rare form of guillan-barre syndrome (gbs). antibodies against other membrane proteins like gm1b and gd1a have been found only in a small number of patients with guillan barre syndrome variant.201325207134
helicobacter hepaticus, a new pathogenic species of the helicobacter genus: similarities and differences with h. pylori.helicobacter hepaticus was discovered in 1992 as a cause of liver cancer in the a/jcr mouse model. in susceptible mice, infection by h. hepaticus causes chronic gastrointestinal inflammation leading to neoplasia. it can also cause morphological changes in breast-glands leading to neoplasm and adenocarcinoma in mouse models. studies performed on humans have revealed that h. hepaticus may also be a human pathogen since infection by h. hepaticus can be associated with cholecystitis, cholelithiasis ...201324475322
bickerstaff brainstem encephalitis in pediatrics - a case report. 201324470835
pathogenesis of human enterovirulent bacteria: lessons from cultured, fully differentiated human colon cancer cell lines.hosts are protected from attack by potentially harmful enteric microorganisms, viruses, and parasites by the polarized fully differentiated epithelial cells that make up the epithelium, providing a physical and functional barrier. enterovirulent bacteria interact with the epithelial polarized cells lining the intestinal barrier, and some invade the cells. a better understanding of the cross talk between enterovirulent bacteria and the polarized intestinal cells has resulted in the identification ...201324006470
the tetr family of regulators.the most common prokaryotic signal transduction mechanisms are the one-component systems in which a single polypeptide contains both a sensory domain and a dna-binding domain. among the >20 classes of one-component systems, the tetr family of regulators (tfrs) are widely associated with antibiotic resistance and the regulation of genes encoding small-molecule exporters. however, tfrs play a much broader role, controlling genes involved in metabolism, antibiotic production, quorum sensing, and ma ...201324006471
cytochrome bd-i in escherichia coli is less sensitive than cytochromes bd-ii or bo'' to inhibition by the carbon monoxide-releasing molecule, corm-3: n-acetylcysteine reduces co-rm uptake and inhibition of respiration.co-releasing molecules (co-rms) are potential therapeutic agents, able to deliver co - a critical gasotransmitter - in biological environments. co-rms are also effective antimicrobial agents; although the mechanisms of action are poorly defined, haem-containing terminal oxidases are primary targets. nevertheless, it is clear from several studies that the effects of co-rms on biological systems are frequently not adequately explained by the release of co: co-rms are generally more potent inhibito ...201323624261
multiplex real-time pcr for detection of campylobacter, salmonella, and shigella.infectious diarrhea can be classified based on its clinical presentation as noninflammatory or inflammatory disease. in developing countries, among inflammatory diarrhea cases, shigella is the most common cause, followed by campylobacter and salmonella. because the time frame in which treatment choices must be made is short and conventional stool cultures lack good sensitivity, there is a need for a rapid, sensitive, and inexpensive detection technique. the purpose of our study was to develop a ...201323761159
synergistic effects of anti-cmea and anti-cmeb peptide nucleic acids on sensitizing campylobacter jejuni to antibiotics.the cmeabc efflux pump in campylobacter jejuni confers resistance to structurally divergent antimicrobials, and inhibition of cmeabc represents a promising strategy to control antibiotic-resistant campylobacter. antisense peptide nucleic acids (pnas) targeting the three components of cmeabc were evaluated for inhibition of cmeabc expression. the result revealed a synergistic effect of the pnas targeting cmea and cmeb on sensitizing c. jejuni to antibiotics. this finding further demonstrates the ...201323817373
mntabc and mnth contribute to systemic staphylococcus aureus infection by competing with calprotectin for nutrient manganese.during infection, vertebrates limit access to manganese and zinc, starving invading pathogens, such as staphylococcus aureus, of these essential metals in a process termed "nutritional immunity." the manganese and zinc binding protein calprotectin is a key component of the nutrient-withholding response, and mice lacking this protein do not sequester manganese from s. aureus liver abscesses. one potential mechanism utilized by s. aureus to minimize host-imposed manganese and zinc starvation is th ...201323817615
characterization of intracellular growth regulator icgr by utilizing transcriptomics to identify mediators of pathogenesis in shigella flexneri.shigella species gram-negative bacteria which cause a diarrheal disease, known as shigellosis, by invading and destroying the colonic mucosa and inducing a robust inflammatory response. with no vaccine available, shigellosis annually kills over 600,000 children in developing countries. this study demonstrates the utility of combining high-throughput bioinformatic methods with in vitro and in vivo assays to provide new insights into pathogenesis. comparisons of in vivo and in vitro gene expressio ...201323753632
serotypes, virulence factors, and antimicrobial susceptibilities of vaginal and fecal isolates of escherichia coli from giant pandas.although escherichia coli typically colonizes the intestinal tract and vagina of giant pandas, it has caused enteric and systemic disease in giant pandas and greatly impacts the health and survival of this endangered species. in order to understand the distribution and characteristics of e. coli from giant pandas, 67 fecal and 30 vaginal e. coli isolates from 21 giant pandas were characterized for o serogroups, phylogenetic groups, antimicrobial susceptibilities, and pulsed-field gel electrophor ...201323793635
measurement of predation and biofilm formation under different ambient oxygen conditions using a simple gasbag-based system.bdellovibrio bacteriovorus and micavibrio aeruginosavorus are gram-negative bacteria characterized by predatory behavior. the aim of this study was to evaluate the ability of the predators to prey in different oxygen environments. when placed on an orbital shaker, a positive association between the rate of aeration and predation was observed. to further examine the effects of elevated ambient oxygen levels on predation, a simple gasbag system was developed. using the system, we were able to cond ...201323811501
multiplex real-time pcr for detecting and typing clostridium botulinum group iii organisms and their mosaic variants.botulism is a neuroparalytic disease that can occur in all warm-blooded animals, birds, and fishes. the disease in animals is mainly caused by toxins produced by clostridium botulinum strains belonging to group iii, although outbreaks due to toxins produced by group i and ii organisms have been recognized. group iii strains are capable of producing botulinum toxins of type c, d, and c/d and d/c mosaic variants. definitive diagnosis of animal botulism is made by combining clinical findings with l ...201323971808
genomic investigation into strain heterogeneity and pathogenic potential of the emerging gastrointestinal pathogen campylobacter ureolyticus.the recent detection and isolation of c. ureolyticus from patients with diarrhoeal illness and inflammatory bowel diseases warrants further investigation into its role as an emerging pathogen of the human gastrointestinal tract. regarding the pathogenic mechanisms employed by this species we provide the first whole genome analysis of two c. ureolyticus isolates including the type strain. comparative analysis, subtractive hybridisation and gene ontology searches against other campylobacter specie ...201324023611
human milk oligosaccharides protect bladder epithelial cells against uropathogenic escherichia coli invasion and cytotoxicity.the invasive pathogen uropathogenic escherichia coli (upec) is the primary cause of urinary tract infections (utis). recurrent infection that can progress to life-threatening renal failure has remained as a serious global health concern in infants. upec adheres to and invades bladder epithelial cells to establish infection. studies have detected the presence of human milk oligosaccharides (hmos) in urine of breast-fed, but not formula-fed, neonates. we investigated the mechanisms hmos deploy to ...201323990566
human milk oligosaccharides protect bladder epithelial cells against uropathogenic escherichia coli invasion and cytotoxicity.the invasive pathogen uropathogenic escherichia coli (upec) is the primary cause of urinary tract infections (utis). recurrent infection that can progress to life-threatening renal failure has remained as a serious global health concern in infants. upec adheres to and invades bladder epithelial cells to establish infection. studies have detected the presence of human milk oligosaccharides (hmos) in urine of breast-fed, but not formula-fed, neonates. we investigated the mechanisms hmos deploy to ...201323990566
glycoconjugates in host-helminth interactions.helminths are multicellular parasitic worms that comprise a major class of human pathogens and cause an immense amount of suffering worldwide. helminths possess an abundance of complex and unique glycoconjugates that interact with both the innate and adaptive arms of immunity in definitive and intermediate hosts. these glycoconjugates represent a major untapped reservoir of immunomodulatory compounds, which have the potential to treat autoimmune and inflammatory disorders, and antigenic glycans, ...201324009607
steroid-responsive polyradiculopathy in association with focal segmental glomerulosclerosis.an 80-year-old woman presented with simultaneous increasing muscle weakness and nephrotic syndrome. a renal biopsy confirmed focal segmental glomerulosclerosis (fsgs). her neurological diagnosis best fitted with a guillain-barre-like syndrome. there have been several cases of fsgs in combination with both conventional and atypical guillain-barre syndrome (gbs). our patient was treated with high-dose steroids and resolution of both nephrotic syndrome and neurological symptoms occurred over 6 mont ...201326069832
population abundance of potentially pathogenic organisms in intestinal microbiome of jungle crow (corvus macrorhynchos) shown with 16s rrna gene-based microbial community analysis.jungle crows (corvus macrorhynchos) prefer human habitats because of their versatility in feeding accompanied with human food consumption. therefore, it is important from a public health viewpoint to characterize their intestinal microbiota. however, no studies have been involved in molecular characterization of the microbiota based on huge and reliable number of data acquisition. in this study, 16s rrna gene-based microbial community analysis coupled with the next-generation dna sequencing tech ...201324058905
complete genome sequence of the arcobacter butzleri cattle isolate 7h1h.arcobacter butzleri strain 7h1h was isolated in the united kingdom from the feces of a clinically healthy dairy cow. the genome of this isolate was sequenced to completion. here, we present the annotation and analysis of the completed 7h1h genome, along with a comparison of this genome to the existing a. butzleri genomes.201323969057
combining quantitative genetic footprinting and trait enrichment analysis to identify fitness determinants of a bacterial pathogen.strains of extraintestinal pathogenic escherichia c oli (expec) exhibit an array of virulence strategies and are a major cause of urinary tract infections, sepsis and meningitis. efforts to understand expec pathogenesis are challenged by the high degree of genetic and phenotypic variation that exists among isolates. determining which virulence traits are widespread and which are strain-specific will greatly benefit the design of more effective therapies. towards this goal, we utilized a quantita ...201323990803
solution nmr structures provide first structural coverage of the large protein domain family pf08369 and complementary structural coverage of dark operative protochlorophyllide oxidoreductase complexes.high-quality nmr structures of the c-terminal domain comprising residues 484-537 of the 537-residue protein bacterial chlorophyll subunit b (bchb) from chlorobium tepidum and residues 9-61 of 61-residue asr4154 from nostoc sp. (strain pcc 7120) exhibit a mixed α/β fold comprised of three α-helices and a small β-sheet packed against second α-helix. these two proteins share 29% sequence similarity and their structures are globally quite similar. the structures of bchb(484-537) and asr4154(9-61) ar ...201323963952
purification, crystallization and preliminary x-ray analysis of adenylosuccinate synthetase from the fungal pathogen cryptococcus neoformans.with increasingly large immunocompromised populations around the world, opportunistic fungal pathogens such as cryptococcus neoformans are a growing cause of morbidity and mortality. to combat the paucity of antifungal compounds, new drug targets must be investigated. adenylosuccinate synthetase is a crucial enzyme in the atp de novo biosynthetic pathway, catalyzing the formation of adenylosuccinate from inosine monophosphate and aspartate. although the enzyme is ubiquitous and well characterize ...201323989157
the complete campylobacter jejuni transcriptome during colonization of a natural host determined by rnaseq.campylobacter jejuni is a major human pathogen and a leading cause of bacterial derived gastroenteritis worldwide. c. jejuni regulates gene expression under various environmental conditions and stresses, indicative of its ability to survive in diverse niches. despite this ability to highly regulate gene transcription, c. jejuni encodes few transcription factors and its genome lacks many canonical transcriptional regulators. high throughput deep sequencing of mrna transcripts (termed rnaseq) has ...201323991199
structure of a sugar n-formyltransferase from campylobacter jejuni.the o-antigens, which are components of the outer membranes of gram-negative bacteria, are responsible for the wide species variations seen in nature and are thought to play a role in bacterial virulence. they often contain unusual dideoxysugars such as 3,6-dideoxy-3-formamido-d-glucose (qui3nfo). here, we describe a structural and functional investigation of the protein c8j_1081 from campylobacter jejuni 81116, which is involved in the biosynthesis of qui3nfo. specifically, the enzyme, hereafte ...201323898784
the role of the gastrointestinal microbiome in helicobacter pylori pathogenesis.the discovery of helicobacter pylori overturned the conventional dogma that the stomach was a sterile organ and that ph values<4 were capable of sterilizing the stomach. h. pylori are an etiological agent associated with gastritis, hypochlorhydria, duodenal ulcers, and gastric cancer. it is now appreciated that the human stomach supports a bacterial community with possibly 100s of bacterial species that influence stomach homeostasis. other bacteria colonizing the stomach may also influence h. py ...201323962822
rab3gap1 mediates exocytosis of claudin-1 and tight junction formation during epidermal barrier acquisition.epidermal barrier acquisition during late murine gestation is accompanied by an increase in akt kinase activity and cjun dephosphorlyation. the latter is directed by the ppp2r2a regulatory subunit of the pp2a phosphatase. this was accompanied by a change of claudin-1 localisation to the cell surface and interaction between occludin and claudin-1 which are thought to be required for tight junction formation. the aim of this study was to determine the nature of the barrier defect caused by the los ...201323685254
mscs-like mechanosensitive channels in plants and microbes.the challenge of osmotic stress is something all living organisms must face as a result of environmental dynamics. over the past three decades, innovative research and cooperation across disciplines have irrefutably established that cells utilize mechanically gated ion channels to release osmolytes and prevent cell lysis during hypoosmotic stress. early electrophysiological analysis of the inner membrane of escherichia coli identified the presence of three distinct mechanosensitive activities. t ...201323947546
shanghai fever: a distinct pseudomonas aeruginosa enteric disease.shanghai fever, a community-acquired enteric illness associated with sepsis caused by pseudomonas aeruginosa, was first described in 1918. the understanding of shanghai fever is incomplete.201323943780
shanghai fever: a distinct pseudomonas aeruginosa enteric disease.shanghai fever, a community-acquired enteric illness associated with sepsis caused by pseudomonas aeruginosa, was first described in 1918. the understanding of shanghai fever is incomplete.201323943780
role of campylobacter jejuni infection in the pathogenesis of guillain-barré syndrome: an update.our current knowledge on campylobacter jejuni infections in humans has progressively increased over the past few decades. infection with c. jejuni is the most common cause of bacterial gastroenteritis, sometimes surpassing other infections due to salmonella, shigella, and escherichia coli. most infections are acquired due to consumption of raw or undercooked poultry, unpasteurized milk, and contaminated water. after developing the diagnostic methods to detect c. jejuni, the possibility to identi ...201324000328
multilocus sequence typing and biocide tolerance of arcobacter butzleri from danish broiler carcasses.arcobacter spp. have in recent years received increasing interest as potential emerging enteropathogens and zoonotic agents. they are associated with various animals including poultry and can be isolated from meat products. the possibilities of persistence and cross-contamination in slaughterhouses during meat processing are not well established. we have evaluated the occurrence and persistence of arcobacter spp. in a danish slaughterhouse and determined the sensitivity of isolates to sodium hyp ...201323941403
global transcriptional response of caulobacter crescentus to iron availability.in the alpha subclass of proteobacteria iron homeostasis is controlled by diverse iron responsive regulators. caulobacter crescentus, an important freshwater α-proteobacterium, uses the ferric uptake repressor (fur) for such purpose. however, the impact of the iron availability on the c. crescentus transcriptome and an overall perspective of the regulatory networks involved remain unknown.201323941329
the pre-synaptic motor nerve terminal as a site for antibody-mediated neurotoxicity in autoimmune neuropathies and synaptopathies.the pre-synaptic motor nerve terminal is a highly complex and dynamic compartment within the lower motor neuron responsible for converting electrical signals into secreted chemicals. this self-renewing process of synaptic transmission is accomplished by the calcium-triggered fusion of neurotransmitter-containing vesicles with the plasma membrane and the subsequent retrieval and recycling of vesicle components. besides this conventional physiological role, the highly active process of vesicle fus ...201323937354
the pre-synaptic motor nerve terminal as a site for antibody-mediated neurotoxicity in autoimmune neuropathies and synaptopathies.the pre-synaptic motor nerve terminal is a highly complex and dynamic compartment within the lower motor neuron responsible for converting electrical signals into secreted chemicals. this self-renewing process of synaptic transmission is accomplished by the calcium-triggered fusion of neurotransmitter-containing vesicles with the plasma membrane and the subsequent retrieval and recycling of vesicle components. besides this conventional physiological role, the highly active process of vesicle fus ...201323937354
antimicrobial action and anti-corrosion effect against sulfate reducing bacteria by lemongrass (cymbopogon citratus) essential oil and its major component, the citral.the anti-corrosion effect and the antimicrobial activity of lemongrass essential oil (leo) against the planktonic and sessile growth of a sulfate reducing bacterium (srb) were evaluated. minimum inhibitory concentration (mic) of leo and its major component, the citral, was 0.17 mg ml-1. in addition, both leo and citral showed an immediate killing effect against srb in liquid medium, suggesting that citral is responsible for the antimicrobial activity of leo against srb. transmission electron mic ...201323938023
ru(co)3cl(glycinate) (corm-3): a carbon monoxide-releasing molecule with broad-spectrum antimicrobial and photosensitive activities against respiration and cation transport in escherichia coli.carbon monoxide (co) delivered to cells and tissues by co-releasing molecules (co-rms) has beneficial and toxic effects not mimicked by co gas. the metal carbonyl ru(co)3cl(glycinate) (corm-3) is a novel, potent antimicrobial agent. here, we established its mode of action.201323186316
intestinal microbiota composition of interleukin-10 deficient c57bl/6j mice and susceptibility to helicobacter hepaticus-induced colitis.the mouse pathobiont helicobacter hepaticus can induce typhlocolitis in interleukin-10-deficient mice, and h. hepaticus infection of immunodeficient mice is widely used as a model to study the role of pathogens and commensal bacteria in the pathogenesis of inflammatory bowel disease. c57bl/6j il10(-/-) mice kept under specific pathogen-free conditions in two different facilities (mhh and mit), displayed strong differences with respect to their susceptibilities to h. hepaticus-induced intestinal ...201323951007
the molecular basis of inactivation of metronidazole-resistant helicobacter pylori using polyethyleneimine functionalized zinc oxide nanoparticles.in view of the world wide prevalence of helicobacter pylori infection, its potentially serious consequences, and the increasing emergence of antibiotic resistant h. pylori strains there is an urgent need for the development of alternative strategies to combat the infection. in this study it has been demonstrated that polyethyleneimine (pei) functionalized zinc oxide (zno) nanoparticles (nps) inhibit the growth of a metronidazole-resistant strain of h. pylori and the molecular basis of the anti-b ...201323951006
[miller fisher syndrome with anti gq1b negative in mycoplasma pneumoniae pneumonia]. 201324255728
arsenic resistance and prevalence of arsenic resistance genes in campylobacter jejuni and campylobacter coli isolated from retail meats.studies that investigate arsenic resistance in the foodborne bacterium campylobacter are limited. a total of 552 campylobacter isolates (281 campylobacter jejuni and 271 campylobacter coli) isolated from retail meat samples were subjected to arsenic resistance profiling using the following arsenic compounds: arsanilic acid (4-2,048 μg/ml), roxarsone (4-2048 μg/ml), arsenate (16-8,192 μg/ml) and arsenite (4-2,048 μg/ml). a total of 223 of these isolates (114 campylobacter jejuni and 109 campyloba ...201323965921
gut microbial flora, prebiotics, and probiotics in ibd: their current usage and utility.inflammatory bowel diseases are chronic diseases affecting the gastrointestinal tract, whose major forms are represented by crohn's disease (cd) and ulcerative colitis (uc). their etiology is still unclear, although several factors have been identified as major determinants for induction or relapses. among these, the role of the "forgotten organ", gut microbiota, has become more appreciated in recent years. the delicate symbiotic relationship between the gut microbiota and the host appears to be ...201323991417
free-ranging chickens in households in a periurban shantytown in peru--attitudes and practices 10 years after a community-based intervention project.free-ranging chickens are often found in periurban communities in developing countries, and their feces can pose a significant public health sanitation problem. corralling chickens raised in these periurban areas in chicken coops has been proposed previously as an intervention to address this problem. aims of this study were to revisit households in a corralling intervention study conducted in 2000-2001 to compare poultry-raising practices and investigate current attitudes regarding the impact o ...201323817335
an analysis of the structural and functional similarities of insect hemocytes and mammalian phagocytes.the insect immune response demonstrates a number of structural and functional similarities to the innate immune system of mammals. as a result of these conserved features insects have become popular choices for evaluating the virulence of microbial pathogens or for assessing the efficacy of antimicrobial agents and give results which are comparable to those that can be obtained using mammals. analysis of the cellular component of the insect and mammalian immune systems demonstrates many similari ...201323921374
campylobacter jejuni pdxa affects flagellum-mediated motility to alter host colonization.vitamin b6 (pyridoxal-5'-phosphate, plp) is linked to a variety of biological functions in prokaryotes. here, we report that the pdxa (putative 4-hydroxy-l-threonine phosphate dehydrogenase) gene plays a pivotal role in the plp-dependent regulation of flagellar motility, thereby altering host colonization in a leading foodborne pathogen, campylobacter jejuni. a c. jejuni pdxa mutant failed to produce plp and exhibited a coincident loss of flagellar motility. mass spectrometric analyses showed a ...201323936426
cloning and characterization of ef-tu and ef-ts from pseudomonas aeruginosa.we have cloned genes encoding elongation factors ef-tu and ef-ts from pseudomonas aeruginosa and expressed and purified the proteins to greater than 95% homogeneity. sequence analysis indicated that p. aeruginosa ef-tu and ef-ts are 84% and 55% identical to e. coli counterparts, respectively. p. aeruginosa ef-tu was active when assayed in gdp exchange assays. kinetic parameters for the interaction of ef-tu with gdp in the absence of ef-ts were observed to be k m = 33 μm, k cat (obs) = 0.003 s(-1 ...201323984384
electron microscopic, genetic and protein expression analyses of helicobacter acinonychis strains from a bengal tiger.colonization by helicobacter species is commonly noted in many mammals. these infections often remain unrecognized, but can cause severe health complications or more subtle host immune perturbations. the aim of this study was to isolate and characterize putative novel helicobacter spp. from bengal tigers in thailand. morphological investigation (gram-staining and electron microscopy) and genetic studies (16srrna, 23srrna, flagellin, urease and prophage gene analyses, rapd dna fingerprinting and ...201323940723
antimicrobial activity of a neem cake extract in a broth model meat system.this work reports on the antimicrobial activity of an ethyl acetate extract of neem (azadirachta indica) cake (nce) against bacteria affecting the quality of retail fresh meat in a broth model meat system. nce (100 µg) was also tested by the agar disc diffusion method. it inhibited the growth of all tested microorganisms. the nce growth inhibition zone (iz) ranged 11.33-22.67 mm while the ciprofloxacin (10 µg) iz ranged from 23.41-32.67 mm. there was no significant difference (p ≤ 0.05) between ...201323917814
campylobacter jejuni ferric-enterobactin receptor cfra is tonb3 dependent and mediates iron acquisition from structurally different catechol siderophores.campylobacter jejuni nctc11168 does not produce any endogenous siderophores of its own yet requires the cfra enterobactin transporter for in vivo colonization. in addition, the genome of c. jejuni nctc11168 contains three distinct tonb energy transduction systems, named tonb1, tonb2, and tonb3, that have not been tested for their role in siderophore uptake or their functional redundancy. we demonstrate that c. jejuni nctc11168 transports ferric-enterobactin in an energy dependent manner that req ...201323702883
adherence to and invasion of human intestinal cells by arcobacter species and their virulence genotypes.the genus arcobacter is composed of 17 species which have been isolated from various sources. of particular interest are a. butzleri, a. cryaerophilus, and a. skirrowii, as these have been associated with human cases of diarrhea, the probable transmission routes being through the ingestion of contaminated drinking water and food. to date, only limited studies of virulence traits in this genus have been undertaken. the present study used 60 arcobacter strains isolated from different sources, repr ...201323770897
a multicopper oxidase is required for copper resistance in mycobacterium tuberculosis.mycobacterium tuberculosis, the causative agent of tuberculosis, is one of the most important bacterial pathogens. recent work has revealed that the natural bactericidal properties of copper are utilized by the host immune system to combat infections with bacteria, including m. tuberculosis. however, m. tuberculosis employs multiple mechanisms to reduce the internal copper amount by efflux and sequestration, which are required for virulence of m. tuberculosis. here, we describe an alternative me ...201323772064
duck liver-associated outbreak of campylobacteriosis among humans, united kingdom, 2011.campylobacter- spp.-related gastroenteritis in diners at a catering college restaurant was associated with consumption of duck liver pâté. population genetic analysis indicated that isolates from duck samples were typical of isolates from farmed poultry. campylobacter spp. contamination of duck liver may present a hazard similar to the increasingly recognized contamination of chicken liver.201323876233
gasotransmitters, poisons, and antimicrobials: it's a gas, gas, gas!we review recent examples of the burgeoning literature on three gases that have major impacts in biology and microbiology. no, co and h2s are now co-classified as endogenous gasotransmitters with profound effects on mammalian physiology and, potentially, major implications in therapeutic applications. all are well known to be toxic yet, at tiny concentrations in human and cell biology, play key signalling and regulatory functions. all may also be endogenously generated in microbes. no and h2s sh ...201323967379
virulence of vancomycin-resistant enterococcus faecium according to linezolid resistance and clinical outbreak status.assessing clinical virulence differences between vancomycin-resistant enterococcus faecium (vref) strains resistant to linezolid (lrvre) and linezolid-susceptible vre (lsvre) strains is difficult due to confounding patient variables. galleria mellonella is a validated host interaction model allowing straightforward organism virulence assessment. the objective of this study was to assess the virulence of vref in g. mellonella according to linezolid resistance and clinical outbreak status. a genet ...201323733458
real-time genomic epidemiological evaluation of human campylobacter isolates by use of whole-genome multilocus sequence typing.sequence-based typing is essential for understanding the epidemiology of campylobacter infections, a major worldwide cause of bacterial gastroenteritis. we demonstrate the practical and rapid exploitation of whole-genome sequencing to provide routine definitive characterization of campylobacter jejuni and campylobacter coli for clinical and public health purposes. short-read data from 384 campylobacter clinical isolates collected over 4 months in oxford, united kingdom, were assembled de novo. c ...201323698529
improved detection of bacterial pathogens in patients presenting with gastroenteritis by use of the entericbio real-time gastro panel i assay.in this study, we evaluated the use of entericbio real-time gastro panel i (serosep, limerick, ireland) for routine use in a clinical microbiology laboratory for simultaneous detection of campylobacter jejuni, coli, and lari, shiga toxin-producing escherichia coli (stec), salmonella spp., and shigella spp. in feces. this system differs from its predecessor (the entericbio panel ii system, serosep) in that it allows real-time detection of pathogens directly from feces, without pre-enrichment. it ...201323761157
broad-spectrum biosensor capable of detecting and identifying diverse bacterial and candida species in blood.we describe an assay which uses broad-spectrum, conserved-site pcr paired with mass spectrometry analysis of amplicons (pcr/electrospray ionization-mass spectrometry [esi-ms]) to detect and identify diverse bacterial and candida species in uncultured specimens. the performance of the assay was characterized using whole-blood samples spiked with low titers of 64 bacterial species and 6 candida species representing the breadth of coverage of the assay. the assay had an average limit of detection o ...201323761152
feob-mediated uptake of iron by francisella tularensis.francisella tularensis, the bacterial cause of tularemia, infects the liver and replicates in hepatocytes in vivo and in vitro. however, the factors that govern adaptation of f. tularensis to the intrahepatocytic niche have not been identified. using cdna microarrays, we determined the transcriptional profile of the live vaccine strain (lvs) of f. tularensis grown in the fl83b murine hepatocytic cell line compared to that of f. tularensis cultured in broth. the fslc gene of the fsl operon was th ...201323716605
divergent mechanisms of interaction of helicobacter pylori and campylobacter jejuni with mucus and mucins.helicobacter pylori and campylobacter jejuni colonize the stomach and intestinal mucus, respectively. using a combination of mucus-secreting cells, purified mucins, and a novel mucin microarray platform, we examined the interactions of these two organisms with mucus and mucins. h. pylori and c. jejuni bound to distinctly different mucins. c. jejuni displayed a striking tropism for chicken gastrointestinal mucins compared to mucins from other animals and preferentially bound mucins from specific ...201323716616
escherichia coli heat-stable toxin b impairs intestinal epithelial barrier function by altering tight junction proteins.escherichia coli heat-stable toxin b (stb) causes diarrhea in animals. stb binds to sulfatide, its receptor, and is then internalized. in the cytoplasm, through a cascade of events, stb triggers the opening of ion channels, allowing ion secretion and water loss and leading to diarrhea. tight junctions (tjs) are well known for controlling paracellular traffic of ions and water by forming a physical intercellular barrier in epithelial cells, and some bacterial toxins are known to affect adversely ...201323716609
allelic variation in a simple sequence repeat element of neisserial pglb2 and its consequences for protein expression and protein glycosylation.neisseria species express an o-linked glycosylation system in which functionally distinct proteins are elaborated with variable glycans. a major source of glycan diversity in n. meningitidis results from two distinct pglb alleles responsible for the synthesis of either n,n'-diacetylbacillosamine or glyceramido-acetamido trideoxyhexose that occupy the reducing end of the oligosaccharides. alternative modifications at c-4 of the precursor udp-4-amino are attributable to distinct c-terminal domains ...201323729645
alignment-free genetic sequence comparisons: a review of recent approaches by word analysis.modern sequencing and genome assembly technologies have provided a wealth of data, which will soon require an analysis by comparison for discovery. sequence alignment, a fundamental task in bioinformatics research, may be used but with some caveats. seminal techniques and methods from dynamic programming are proving ineffective for this work owing to their inherent computational expense when processing large amounts of sequence data. these methods are prone to giving misleading information becau ...201323904502
alignment-free genetic sequence comparisons: a review of recent approaches by word analysis.modern sequencing and genome assembly technologies have provided a wealth of data, which will soon require an analysis by comparison for discovery. sequence alignment, a fundamental task in bioinformatics research, may be used but with some caveats. seminal techniques and methods from dynamic programming are proving ineffective for this work owing to their inherent computational expense when processing large amounts of sequence data. these methods are prone to giving misleading information becau ...201323904502
contribution of helicobacter hepaticus cytolethal distending toxin subunits to human epithelial cell cycle arrest and apoptotic death in vitro.cytolethal distending toxin (cdt) is the only known virulence factor found in h. hepaticus, the cause of chronic typhlocolitis and hepatitis leading to colonic and hepatocellular carcinomas in mice. interaction of the tripartite polypeptide cdta, cdtb, and cdtc subunits produced by h. hepaticus cdt (hhepcdt) causes cell cycle arrest and apoptotic death of cultured cells; however, the contribution of individual subunit to these processes has not been investigated.201323895367
discovery of streptococcus pneumoniae serotype 6 variants with glycosyltransferases synthesizing two differing repeating units.streptococcus pneumoniae is a persistent, opportunistic commensal of the human nasopharynx and is the leading cause of community-acquired pneumonia. it expresses an anti-phagocytic capsular polysaccharide (ps). genetic variation of the capsular ps synthesis (cps) locus is the molecular basis for structural and antigenic heterogeneity of capsule types (serotypes). serogroup 6 has four known members (6a-6d) with distinct serologic properties, homologous cps loci, and structurally similar pss. cps ...201323897812
the role of chemokines in guillain-barré syndrome.chemokines and their receptors are important mediators of inflammation. guillain-barré syndrome (gbs) is the most common cause of acute paralysis worldwide. despite current treatments, outcomes are suboptimal. specific chemokine receptor antagonists have the potential to be efficacious against pathogenic leukocyte trafficking in gbs.201323447114
bio-recognition and functional lipidomics by glycosphingolipid transfer technology.through glycosphingolipid biochemical research, we developed two types of transcription technologies. one is a biochemical transfer of glycosphingolipids to peptides. the other is a physicochemical transfer of glycosphingolipids in silica gel to the surface of a plastic membrane. using the first technology, we could prepare peptides which mimic the shapes of glycosphingolipid molecules by biopanning with a phage-displayed peptide library and anti-glycosphingolipid antibodies as templates. the pe ...201323883610
causal inference regarding infectious aetiology of chronic conditions: a systematic review.the global burden of disease has shifted from communicable diseases in children to chronic diseases in adults. this epidemiologic shift varies greatly by region, but in europe, chronic conditions account for 86% of all deaths, 77% of the disease burden, and up to 80% of health care expenditures. a number of risk factors have been implicated in chronic diseases, such as exposure to infectious agents. a number of associations have been well established while others remain uncertain.201323935899
detection of calprotectin and apoptotic activity in the colon of marmosets with chronic diarrhea.the common marmoset (callithrix jacchus) is used as a non-human primate laboratory animal. marmoset wasting syndrome (mws) is a disease endemic to captive colonies, and the pathogenesis is unclear. in the present study, marmosets with chronic bloody high-viscosity diarrhea, which is a contributing factor to mws, were evaluated, and inflammation in the colon was found. calprotectin is a surrogate marker of intestinal inflammation and induces apoptosis. marmosets with chronic diarrhea exhibited hi ...201323884022
campylobacter jejuni colonization and population structure in urban populations of ducks and starlings in new zealand.a repeated cross-sectional study was conducted to determine the prevalence of campylobacter spp. and the population structure of c. jejuni in european starlings and ducks cohabiting multiple public access sites in an urban area of new zealand. the country's geographical isolation and relatively recent history of introduction of wild bird species, including the european starling and mallard duck, create an ideal setting to explore the impact of geographical separation on the population biology of ...201323873654
complete genome sequence of the cystic fibrosis pathogen achromobacter xylosoxidans nh44784-1996 complies with important pathogenic phenotypes.achromobacter xylosoxidans is an environmental opportunistic pathogen, which infects an increasing number of immunocompromised patients. in this study we combined genomic analysis of a clinical isolated a. xylosoxidans strain with phenotypic investigations of its important pathogenic features. we present a complete assembly of the genome of a. xylosoxidans nh44784-1996, an isolate from a cystic fibrosis patient obtained in 1996. the genome of a. xylosoxidans nh44784-1996 contains approximately 7 ...201323894309
allelic variation in two distinct pseudomonas syringae flagellin epitopes modulates the strength of plant immune responses but not bacterial motility.the bacterial flagellin (flic) epitopes flg22 and flgii-28 are microbe-associated molecular patterns (mamps). although flg22 is recognized by many plant species via the pattern recognition receptor fls2, neither the flgii-28 receptor nor the extent of flgii-28 recognition by different plant families is known. here, we tested the significance of flgii-28 as a mamp and the importance of allelic diversity in flg22 and flgii-28 in plant-pathogen interactions using purified peptides and a pseudomonas ...201323865782
scoping review on search queries and social media for disease surveillance: a chronology of innovation.the threat of a global pandemic posed by outbreaks of influenza h5n1 (1997) and severe acute respiratory syndrome (sars, 2002), both diseases of zoonotic origin, provoked interest in improving early warning systems and reinforced the need for combining data from different sources. it led to the use of search query data from search engines such as google and yahoo! as an indicator of when and where influenza was occurring. this methodology has subsequently been extended to other diseases and has ...201323896182
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