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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
deamination of 6-aminodeoxyfutalosine in menaquinone biosynthesis by distantly related enzymes.proteins of unknown function belonging to cog1816 and cog0402 were characterized. sav2595 from steptomyces avermitilis ma-4680, acel0264 from acidothermus cellulolyticus 11b, nis0429 from nitratiruptor sp. sb155-2 and dr0824 from deinococcus radiodurans r1 were cloned, purified, and their substrate profiles determined. these enzymes were previously incorrectly annotated as adenosine deaminases or chlorohydrolases. it was shown here that these enzymes actually deaminate 6-aminodeoxyfutalosine. th ...201323972005
pasteurella multocida heddleston serovar 3 and 4 strains share a common lipopolysaccharide biosynthesis locus but display both inter- and intrastrain lipopolysaccharide heterogeneity.pasteurella multocida is a gram-negative multispecies pathogen and the causative agent of fowl cholera, a serious disease of poultry which can present in both acute and chronic forms. the major outer membrane component lipopolysaccharide (lps) is both an important virulence factor and a major immunogen. our previous studies determined the lps structures expressed by different p. multocida strains and revealed that a number of strains belonging to different serovars contain the same lps biosynthe ...201323974032
transcriptional profiling of neisseria meningitidis interacting with human epithelial cells in a long-term in vitro colonization model.neisseria meningitidis is a commensal of humans that can colonize the nasopharyngeal epithelium for weeks to months and occasionally invades to cause life-threatening septicemia and meningitis. comparatively little is known about meningococcal gene expression during colonization beyond those first few hours. in this study, the transcriptome of adherent serogroup b n. meningitidis strain mc58 was determined at intervals during prolonged cocultivation with confluent monolayers of the human respira ...201323980104
relative contributions of lipooligosaccharide inner and outer core modifications to nontypeable haemophilus influenzae pathogenesis.nontypeable haemophilus influenzae (nthi) is a frequent commensal of the human nasopharynx that causes opportunistic infection in immunocompromised individuals. existing evidence associates lipooligosaccharide (los) with disease, but the specific and relative contributions of nthi los modifications to virulence properties of the bacterium have not been comprehensively addressed. using nthi strain 375, an isolate for which the detailed los structure has been determined, we compared systematically ...201323980106
inpatient management of guillain-barré syndrome.guillain-barré syndrome (gbs) is the most common cause of acute flaccid paralysis in the developed world. guillain-barré syndrome typically presents with ascending paralysis and is usually severe enough to warrant hospital admission for management. in the united states alone, gbs results in more than 6000 hospitalizations each year. although gbs patients were historically cared for at tertiary referral centers, changing treatment practices have broadened the number of neurologists who care for t ...201123983841
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
comparative genomics of campylobacter concisus isolates reveals genetic diversity and provides insights into disease association.in spite of its association with gastroenteritis and inflammatory bowel diseases, the isolation of campylobacter concisus from both diseased and healthy individuals has led to controversy regarding its role as an intestinal pathogen. one proposed reason for this is the presence of high genetic diversity among the genomes of c. concisus strains.201323984967
recurrent outbreak of campylobacter jejuni infections associated with a raw milk dairy--pennsylvania, april-may 2013.during may 2013, the pennsylvania department of health investigated an outbreak of campylobacteriosis among consumers of raw (unpasteurized) milk from a dairy certified by the pennsylvania department of agriculture (pda) to sell raw milk onsite, at retail stores, and at off-farm pick-up sites. investigation by the pennsylvania department of health and pda identified six confirmed and two probable cases of campylobacteriosis associated with raw milk from the dairy. a confirmed case was defined as ...201323985499
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
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
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
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
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
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
safety of long-term ppi therapy.proton pump inhibitors have become the mainstay of medical treatment of acid-related disorders. long-term use is becoming increasingly common, in some cases without a proper indication. a large number of mainly observational studies on a very wide range of possible associations have been published in the past decade and are critically reviewed in this article and the existing evidence is evaluated and translated into possible clinical consequences. based on the existing evidence the benefits of ...201323998981
topoisomerase iv is required for partitioning of circular chromosomes but not linear chromosomes in streptomyces.filamentous bacteria of the genus streptomyces possess linear chromosomes and linear plasmids. theoretically, linear replicons may not need a decatenase for post-replicational separation of daughter molecules. yet, streptomyces contain parc and pare that encode the subunits for the decatenase topoisomerase iv. the linear replicons of streptomyces adopt a circular configuration in vivo through telomere-telomere interaction, which would require decatenation, if the circular configuration persists ...201323999094
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
deciphering the contribution of human meningothelial cells to the inflammatory and antimicrobial response at the meninges.we have investigated the response of primary human meningothelial cells to neisseria meningitidis. through a transcriptome analysis, we provide a comprehensive examination of the response of meningothelial cells to bacterial infection. a wide range of chemokines are elicited which act to attract and activate the main players of innate and adaptive immunity. we showed that meningothelial cells expressed a high level of toll-like receptor 4 (tlr4), and, using a gene silencing strategy, we demonstr ...201324002066
formative research on hygiene behaviors and geophagy among infants and young children and implications of exposure to fecal bacteria.we conducted direct observation of 23 caregiver-infant pairs for 130 hours and recorded wash-related behaviors to identify pathways of fecal-oral transmission of bacteria among infants. in addition to testing fingers, food, and drinking water of infants, three infants actively ingested 11.3 ± 9.2 (mean ± sd) handfuls of soil and two ingested chicken feces 2 ± 1.4 times in 6 hours. hand washing with soap was not common and drinking water was contaminated with escherichia coli in half (12 of 22) o ...201324002485
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 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
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
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
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
periplasmic flagellar export apparatus protein, flih, is involved in post-transcriptional regulation of flab, motility and virulence of the relapsing fever spirochete borrelia hermsii.spirochetes are bacteria characterized in part by rotating periplasmic flagella that impart their helical or flat-wave morphology and motility. while most other bacteria rely on a transcriptional cascade to regulate the expression of motility genes, spirochetes employ post-transcriptional mechanism(s) that are only partially known. in the present study, we characterize a spontaneous non-motile mutant of the relapsing fever spirochete borrelia hermsii that was straight, non-motile and deficient i ...201324009690
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
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
insights into the mode of action of benzyl isothiocyanate on campylobacter jejuni.campylobacter jejuni is a widespread pathogen responsible for most of the food-borne gastrointestinal diseases in europe. the use of natural antimicrobial molecules is a promising alternative to antibiotic treatments for pathogen control in the food industry. isothiocyanates are natural antimicrobial compounds, which also display anticancer activity. several studies described the chemoprotective effect of isothiocyanates on eukaryotic cells, but the antimicrobial mechanism is still poorly unders ...201324014524
preventing campylobacter at the source: why is it so difficult?campylobacteriosis in humans, caused by campylobacter jejuni and campylobacter coli, is the most common recognized bacterial zoonosis in the european union and the united states. the acute phase is characterized by gastrointestinal symptoms. the long-term sequelae (guillain-barré syndrome, reactive arthritis, and postinfectious irritable bowel syndrome) contribute considerably to the disease burden. attribution studies identified poultry as the reservoir responsible for up to 80% of the human ca ...201324014733
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
effect of ciprofloxacin exposure on dna repair mechanisms in campylobacter jejuni.ciprofloxacin resistance is common both among animal and human campylobacter jejuni isolates. resistant isolates are shown to persist even without selection pressure. to obtain further insight on effects of ciprofloxacin exposure on c. jejuni we compared transcriptional responses of both c. jejuni wild-type strain 81-176 (ciprofloxacin mic 0.125 mg l(-1)) and its intermediate ciprofloxacin-resistant variant p3 (asp90→asn in gyra) in the absence and presence of ciprofloxacin. further, we sequence ...201324025607
risk factors for campylobacteriosis in two washington state counties with high numbers of dairy farms.campylobacteriosis is a frequently reported, food-borne, human bacterial disease that can be associated with ruminant reservoirs, although public health messages primarily focus on poultry. in washington state, the two counties with the highest concentrations of dairy cattle also report the highest incidences of campylobacteriosis. conditional logistic regression analysis of case-control data from both counties found living or working on a dairy farm (odds ratio [or], 6.7 [95% confidence interva ...201324025908
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
detection of salmonella sp in chicken cuts using immunomagnetic separation.the immunomagnetic separation (ims) is a technique that has been used to increase sensitivity and specificity and to decrease the time required for detection of salmonella in foods through different methodologies. in this work we report on the development of a method for detection of salmonella in chicken cuts using in house antibody-sensitized microspheres associated to conventional plating in selective agar (ims-plating). first, protein a-coated microspheres were sensitized with polyclonal ant ...200824031199
antimicrobial resistance in campylobacter spp isolated from broiler flocks.the aim of this study was to assess the antimicrobial susceptibility of 62 campylobacter spp. strains obtained from broiler flocks using the agar diffusion method. the campylobacter spp strains were isolated from 22 flocks aged between 3 and 5 weeks of life, isolated from cloacae swabs, stools and cecal droppings in the farm and from the carcass rinsing in the slaughterhouse. campylobacter spp strains were tested on mueller-hilton (mh) agar (27 samples) and mh plus ttc agar (35 samples). the ant ...200824031299
occurrence of campylobacter jejuni and campylobacter coli and their biotypes in beef and dairy cattle from the south of chile.the prevalence of campylobacter jejuni and campylobacter coli and their biotypes in beef and dairy cattle from the south of chile was established. campylobacter were statistically more prevalent among beef cattle (35.9%) than among dairy cattle (21.3%), being c. jejuni the species most frequently isolated.200924031386
use of pcr-rflp of the fla a gene for detection and subtyping of campylobacter jejuni strains potentially related to guillain-barré syndrome, isolated from humans and animals.the objectives of the present study were the subtyping of campylobacter jejuni subsp. jejuni strains obtained from humans and different animal species using pcr-rflp, and the detection, by means of the same technique, of strains related to serotype pen o19:lio 7, the main c. jejuni serotype linked to guillain-barré syndrome (gbs). seventy c. jejuni strains isolated from human feces (n=33), primates (n=15), dogs (n=5), swine (n=2), bovines (n=1), abortion material from goats (n=2) and poultry car ...200924031446
effect of refrigeration and frozen storage on the campylobacter jejuni recovery from naturally contaminated broiler carcasses.campylobacter jejuni is the most common thermophilic campylobacter associated with human enteritis in many countries. broilers and their by-products are the main sources for human enteritis. refrigeration and freezing are used to control bacterial growth in foods. the effect of these interventions on survival of campylobacter jejuni is yet not quite understood. this study evaluated the effect of storage temperature on the survival of c. jejuni in chicken meat stored for seven days at 4°c and for ...201024031523
comparative analysis of cultural isolation and pcr based assay for detection of campylobacter jejuni in food and faecal samples.in the present study, the efficacy of polymerase chain reaction (pcr) based on mapa gene of c. jejuni was tested for detection of campylobacter jejuni in naturally infected as well as spiked faecal and food samples of human and animal origin. simultaneously, all the samples were subjected to the cultural isolation of organism and biochemical characterization. the positive samples resulted in the amplification of a dna fragment of size ~589 bp in pcr assay whereas the absence of such amplicon in ...201124031619
arcobacter butzleri: first isolation report from chicken carcasses in costa rica.arcobacter butzleri isolation from chicken carcasses in costa rica is reported for the first time. the isolated strains (p and r) were presumptively identified by their phenotypic characteristics. definitive identification was made using a multiplex pcr assay for the simultaneous detection and identification of arcobacter butzleri, arcobacter cryaerophilus and arcobacter skirrowii. these first isolations indicate the necessity of further investigation about the prevalence, distribution, ecology ...201124031682
clinical importance and representation of toxigenic and non-toxigenic clostridium difficile cultivated from stool samples of hospitalized patients.the aim of this study was to fortify the clinical importance and representation of toxigenic and non-toxigenic clostridium difficile isolated from stool samples of hospitalized patients. this survey included 80 hospitalized patients with diarrhea and positive findings of clostridium difficile in stool samples, and 100 hospitalized patients with formed stool as a control group. bacteriological examination of a stool samples was conducted using standard microbiological methods. stool sample were i ...201224031820
activity of disinfectants against foodborne pathogens in suspension and adhered to stainless steel surfaces.the purpose of this study was to investigate and compare the efficacy of various disinfectants on planktonic cells and biofilm cells of listeria monocytogenes, staphylococcus aureus and escherichia coli. numbers of viable biofilm cells decreased after treatment with all tested disinfectants (iodine, biguanide, quaternary ammonium compounds, peracetic acid and sodium hypochlorite). sodium hypochlorite was the most effective disinfectant against biofilm cells, while biguanide was the least effecti ...201224031935
oxygen limitation favors the production of protein with antimicrobial activity in pseudoalteromonas sp.this study examined the effect of dissolved oxygen concentration on the production of biomass and metabolites with antimicrobial activity of pseudoalteromonas sp cultured at 0, 150, 250, or 450 revolutions per minute (rev. min(-1)). dissolved oxygen (d.o) was monitored during the fermentation process, biomass was quantified by dry weight, and antimicrobial activity was assessed using the disk diffusion method. the bacterium pseudoalteromonas reached similar concentration of biomass under all exp ...201224031945
campylobacter jejuni and cytopenias.leukopenia and thrombocytopenia in a febrile patient are not uncommon and may be a diagnostic clue in patients without an alternative explanation for cytopenias. this has not been reported in campylobacter jejuni infections.201324034076
haemophilus parainfluenzae expresses diverse lipopolysaccharide o-antigens using abc transporter and wzy polymerase-dependent mechanisms.lipopolysaccharide o-antigens are the basis of serotyping schemes for gram negative bacteria and help to determine the nature of host-bacterial interactions. haemophilus parainfluenzae is a normal commensal of humans but is also an occasional pathogen. the prevalence, diversity and biosynthesis of o-antigens were investigated in this species for the first time. 18/18 commensal h. parainfluenzae isolates contain a o-antigen biosynthesis gene cluster flanked by glna and pepb, the same position as ...201324035104
sandwich assay for mixed-sequence recognition of double-stranded dna: invader-based detection of targets specific to foodborne pathogens.a 96-well plate sandwich assay based on invader capture/signalling probes is used to recognize 28-mer mixed-sequence dsdna targets specific to salmonella enterica, campylobacter jejuni, escherichia coli. targets are detected down to 20-55 pm concentration with excellent binding specificity.201324036937
catabolism of host-derived compounds during extracellular bacterial infections.efficient catabolism of host-derived compounds is essential for bacterial survival and virulence. while these links in intracellular bacteria are well studied, such studies in extracellular bacteria lag behind, mostly for technical reasons. the field has identified important metabolic pathways, but the mechanisms by which they impact infection and in particular, establishing the importance of a compound's catabolism versus alternate metabolic roles has been difficult. in this review we will exam ...201424038340
accumulation and inactivation of avian influenza virus by the filter-feeding invertebrate daphnia magna.the principal mode of avian influenza a virus (aiv) transmission among wild birds is thought to occur via an indirect fecal-oral route, whereby individuals are exposed to virus from the environment through contact with virus-contaminated water. aiv can remain viable for an extended time in water; however, little is known regarding the influence of the biotic community (i.e., aquatic invertebrates) on virus persistence and infectivity in aquatic environments. we conducted laboratory experiments t ...201324038705
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
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
antimicrobial activity of essential oils and five terpenoid compounds against campylobacter jejuni in pure and mixed culture experiments.the aim of this study was to examine the antimicrobial potential of three essential oils (eos: tea tree oil, lemon myrtle oil and leptospermum oil), five terpenoid compounds (α-bisabolol, α-terpinene, cineole, nerolidol and terpinen-4-ol) and polyphenol against two strains of campylobacter jejuni (acm 3393 and the poultry isolate c338), campylobacter coli and other gram negative and gram positive bacteria. different formulations of neem oil (azadirachta indica) with these compounds were also tes ...201324041998
clonal distribution and virulence of campylobacter jejuni isolates in blood.campylobacter jejuni bacteria are highly diverse enteropathogens. seventy-three c. jejuni isolates from blood collected in finland were analyzed by multilocus sequence typing and serum resistance. approximately half of the isolates belonged to the otherwise uncommon sequence type 677 clonal complex. isolates of this clonal complex were more resistant than other isolates to human serum.201324047729
quantitative detection of vibrio cholera toxin by real-time and dynamic cytotoxicity monitoring.we report here the quantitative detection of vibrio cholerae toxin (ct) in isolates and stool specimens by dynamic monitoring of the full course of ct-mediated cytotoxicity in a real-time cell analysis (rtca) system. four cell lines, including y-1 mouse adrenal tumor cells, chinese hamster ovary (cho) cells, small intestine epithelial (fhs74int) cells, and mouse adrenal gland (pc12-adh) cells, were evaluated for their suitability for ct-induced cytotoxicity testing. among them, the y-1 line was ...201324048535
clinical evaluation of a real-time pcr assay for identification of salmonella, shigella, campylobacter (campylobacter jejuni and c. coli), and shiga toxin-producing escherichia coli isolates in stool specimens.enteric illness affects millions of individuals annually in the united states and results in >50,000 hospitalizations. the rapid and accurate identification of bacterial pathogens associated with gastroenteritis can aid acute patient management decisions, including the use of antibiotic therapy and infection control. this study compared the progastro sscs multiplex real-time pcr assay (gen-probe prodesse, san diego, ca) to culture for the identification of campylobacter spp. (campylobacter jejun ...201324048539
reactive arthritis induced by bacterial vaginosis: prevention with an effective treatment.we report a 42-year-old woman with reactive arthritis induced by bacterial vaginosis who presented with oligoarthritis with an additive form, arthralgia, and enthesitis. she hasn't had a history of diarrhea or dysuria or vaginal secretion, or sexually transmitted infections (stis). the laboratory tests were normal except for a high erythrocyte sedimentation rate (esr). her pelvic examination revealed homogeneous white grey and malodorous vaginal discharge on the vaginal wall and pap smear and gr ...201324049604
the globins of campylobacter jejuni.campylobacter jejuni is a zoonotic gram-negative bacterial pathogen that is exposed to reactive nitrogen species, such as nitric oxide, from a variety of sources. to combat the toxic effects of this nitrosative stress, c. jejuni upregulates a small regulon under the control of the transcriptional activator nssr, which positively regulates the expression of a single-domain globin protein (cgb) and a truncated globin protein (ctb). cgb has previously been shown to detoxify nitric oxide, but the ro ...201324054796
a distant homologue of the flgt protein interacts with motb and flil and is essential for flagellar rotation in rhodobacter sphaeroides.in this work, we describe a periplasmic protein that is essential for flagellar rotation in rhodobacter sphaeroides. this protein is encoded upstream of flga, and its expression is dependent on the flagellar master regulator fleq and on the class iii flagellar activator flet. sequence comparisons suggest that this protein is a distant homologue of flgt. we show evidence that in r. sphaeroides, flgt interacts with the periplasmic regions of motb and flil and with the flagellar protein motf, which ...201324056105
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
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
[nosocomial diarrhea in intensive care unit: other than clostridium difficile].to investigate the incidence and clinical features of non-clostridium difficile (c. difficile) associated nosocomial diarrhea in intensive care unit (icu) caused by klebsiella oxytoca and clostridium perfringens.201324059125
isolation and characterization of antimicrobial constituents of searsia chirindensis l. (anacardiaceae) leaf extracts.searsia chirindensis is used in south african traditional medicine for management of bacterial infections such as diarrhoea. aim of the study was to examine the phytochemical composition from the leaves of searsia chirindensis that is responsible for the ethnomedicinal use of this plant.201324060408
from ambivalent to divalent: has the "zinc age" finally arrived? 201324061143
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
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
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
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
mucosal vaccines: where do we stand?mucosal vaccinology is a relatively young but rapidly expanding discipline. at present the vast majority of vaccines are administered by injection, including vaccines that protect against mucosally acquired pathogens such as influenza virus and human papilloma virus. however, mucosal immune responses are most efficiently induced by the administration of vaccines onto mucosal surfaces. the small number of currently licensed mucosal vaccines have reduced the burden of disease and mortality caused ...201324066889
an epidemiological investigation of campylobacter in pig and poultry farms in the mekong delta of vietnam.campylobacter are zoonotic pathogens commonly associated with gastroenteritis. to assess the relevance of campylobacter in vietnam, an economically transitioning country in se asia, we conducted a survey of 343 pig and poultry farms in the mekong delta, a region characterized by mixed species farming with limited biosecurity. the animal-level prevalence of campylobacter was 31·9%, 23·9% and 53·7% for chickens, ducks and pigs, respectively. c. jejuni was predominant in all three host species, wit ...201424067502
an epidemiological investigation of campylobacter in pig and poultry farms in the mekong delta of vietnam.campylobacter are zoonotic pathogens commonly associated with gastroenteritis. to assess the relevance of campylobacter in vietnam, an economically transitioning country in se asia, we conducted a survey of 343 pig and poultry farms in the mekong delta, a region characterized by mixed species farming with limited biosecurity. the animal-level prevalence of campylobacter was 31·9%, 23·9% and 53·7% for chickens, ducks and pigs, respectively. c. jejuni was predominant in all three host species, wit ...201424067502
multilocus sequence typing of borrelia burgdorferi suggests existence of lineages with differential pathogenic properties in humans.the clinical manifestations of lyme disease, caused by borrelia burgdorferi, vary considerably in different patients, possibly due to infection by strains with varying pathogenicity. both rrna intergenic spacer and ospc typing methods have proven to be useful tools for categorizing b. burgdorferi strains that vary in their tendency to disseminate in humans. neither method, however, is suitable for inferring intraspecific relationships among strains that are important for understanding the evolut ...201324069170
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
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
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
geographic setting influences great lakes beach microbiological water quality.understanding of factors that influence escherichia coli (ec) and enterococci (ent) concentrations, pathogen occurrence, and microbial sources at great lakes beaches comes largely from individual beach studies. using 12 representative beaches, we tested enrichment cultures from 273 beach water and 22 tributary samples for ec, ent, and genes indicating the bacterial pathogens shiga-toxin producing e. coli (stec), shigella spp. , salmonella spp , campylobacter jejuni/coli , and methicillin-resista ...201324073635
changes in the symptom pattern and the densities of large-intestinal endocrine cells following campylobacter infection in irritable bowel syndrome: a case report.irritable bowel syndrome (ibs) is a common chronic functional gastrointestinal disorder. post-infectious ibs (pi-ibs) is a subset of ibs that accounts for a large proportion of ibs patients. the pi-ibs symptoms meet the rome criteria for ibs with diarrhoea (ibs-d) or ibs with mixed bowel habits (ibs-m). a low-grade inflammation has been reported to occur in pi-ibs. abnormalities in intestinal endocrine cells have been reported in both sporadic ibs and pi-ibs.201324073715
comparison of rectal swabs and faeces for real-time pcr detection of enteric agents in rwandan children with gastroenteritis.molecular diagnostics have emerged as an efficient and feasible alternative for broad detection of pathogens in faeces. however, collection of stool samples is often impractical in both clinical work and in epidemiology studies. the aim of this study was to investigate the diagnostic performance of rectal swabs as compared with traditional faeces samples for detection of enteric agents by pcr.201324073740
characterization of the biochemical properties of campylobacter jejuni rnase iii.campylobacter jejuni is a foodborne bacterial pathogen, which is now considered as a leading cause of human bacterial gastroenteritis. the information regarding ribonucleases in c. jejuni is very scarce but there are hints that they can be instrumental in virulence mechanisms. namely, pnpase (polynucleotide phosphorylase) was shown to allow survival of c. jejuni in refrigerated conditions, to facilitate bacterial swimming, cell adhesion, colonization and invasion. in several microorganisms pnpas ...201324073828
bioengineered 2'-fucosyllactose and 3-fucosyllactose inhibit the adhesion of pseudomonas aeruginosa and enteric pathogens to human intestinal and respiratory cell lines.human milk oligosaccharides help to prevent infectious diseases in breastfed infants. larger scale testing, particularly in animal models and human clinical studies, is still limited due to shortened availability of more complex oligosaccharides. the purpose of this study was to evaluate 2'-fucosyllactose (2'-fl) and 3-fucosyllactose (3-fl) synthesized by whole-cell biocatalysis for their biological activity in vitro. therefore, we have tested these oligosaccharides for their inhibitory potentia ...201324074741
a boy with iga nephropathy complicated by tubulointerstitial nephritis and uveitis (tinu) syndrome.abnormal cellular and humoral immunity underlie both immunoglobulin a (iga) nephropathy and tubulointerstitial nephritis and uveitis (tinu) syndrome. we encountered a teenage boy who developed tinu syndrome during the course of iga nephropathy.201524075025
effect of bacteriophage application on campylobacter jejuni loads in commercial broiler flocks.campylobacteriosis is the most frequent food-borne human enteritis. the major source for infection with campylobacter spp. is broiler meat. risk assessments consider the reduction of campylobacter in primary production to be most beneficial for human health. the aim of this study was to test the efficacy of a bacteriophage application under commercial conditions which had proved to be effective in previous noncommercial studies under controlled experimental conditions. a phage cocktail for campy ...201324077703
effect of incubation temperature on the detection of thermophilic campylobacter species from freshwater beaches, nearby wastewater effluents, and bird fecal droppings.this large-scale study compared incubation temperatures (37°c versus 42°c) to study the detection of thermophilic campylobacter species, including campylobacter jejuni, c. coli, and c. lari, in various surface water samples and bird fecal droppings around hamilton harbor, lake ontario. the putative culture isolates obtained from incubation temperatures of 37 and 42°c were confirmed by campylobacter genus- and species-specific triplex pcr assays targeting the 16s rrna gene and the 16s-23s rrna ge ...201324077717
archaeal signal transduction: impact of protein phosphatase deletions on cell size, motility, and energy metabolism in sulfolobus acidocaldarius.in this study, the in vitro and in vivo functions of the only two identified protein phosphatases, saci-ptp and saci-pp2a, in the crenarchaeal model organism sulfolobus acidocaldarius were investigated. biochemical characterization revealed that saci-ptp is a dual-specific phosphatase (against pser/pthr and ptyr), whereas saci-pp2a exhibited specific pser/pthr activity and inhibition by okadaic acid. deletion of saci_pp2a resulted in pronounced alterations in growth, cell shape and cell size, wh ...201324078887
transmigration route of campylobacter jejuni across polarized intestinal epithelial cells: paracellular, transcellular or both?intact intercellular junctions and cellular matrix contacts are crucial structural components for the formation and maintenance of epithelial barrier functions in humans to control the commensal flora and protect against intruding microbes. campylobacter jejuni is one of the most important zoonotic pathogens causing food-borne gastroenteritis and potentially more severe diseases such as reactive arthritis or guillain-barré syndrome. crossing the intestinal epithelial barrier and host cell invasi ...201324079544
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
gut microbiota dysbiosis and bacterial community assembly associated with cholesterol gallstones in large-scale study.elucidating gut microbiota among gallstone patients as well as the complex bacterial colonization of cholesterol gallstones may help in both the prediction and subsequent lowered risk of cholelithiasis. to this end, we studied the composition of bacterial communities of gut, bile, and gallstones from 29 gallstone patients as well as the gut of 38 normal individuals, examining and analyzing some 299, 217 bacterial 16s rrna gene sequences from 120 samples.201324083370
target optimization for peptide nucleic acid (pna)-mediated antisense inhibition of the cmeabc multidrug efflux pump in campylobacter jejuni.cmeabc is a resistance-nodulation-cell division (rnd)-type multidrug efflux pump conferring resistance to clinically important antibiotics in campylobacter. this study aimed to identify the optimal target sites for the inhibition of cmeabc with antisense peptide nucleic acid (pna).201424084637
target optimization for peptide nucleic acid (pna)-mediated antisense inhibition of the cmeabc multidrug efflux pump in campylobacter jejuni.cmeabc is a resistance-nodulation-cell division (rnd)-type multidrug efflux pump conferring resistance to clinically important antibiotics in campylobacter. this study aimed to identify the optimal target sites for the inhibition of cmeabc with antisense peptide nucleic acid (pna).201424084637
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
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
quantitative assessment of infection risk from exposure to waterborne pathogens in urban floodwater.flooding and heavy rainfall have been associated with waterborne infectious disease outbreaks, however, it is unclear to which extent they pose a risk for public health. here, risks of infection from exposure to urban floodwater were assessed using quantitative microbial risk assessment (qmra). to that aim, urban floodwaters were sampled in the netherlands during 23 events in 2011 and 2012. the water contained campylobacter jejuni (prevalence 61%, range 14- >10(3) mpn/l), giardia spp. (35%, 0.1- ...201424095592
description of a riboflavin biosynthetic gene variant prevalent in the phylum proteobacteria.riboflavin (vitamin b2) is the precursor of flavin mononucleotide and flavin adenine dinucleotide, which are cofactors essential for a host of intracellular redox reactions. microorganisms synthesize flavins de novo to fulfill nutritional requirements, but it is becoming increasingly clear that flavins play a wider role in cellular physiology than was previously appreciated. flavins mediate diverse processes beyond the cytoplasmic membrane, including iron acquisition, extracellular respiration, ...201324097946
identification and characterization of novel helicobacter pylori apo-fur-regulated target genes.in helicobacter pylori, the ferric uptake regulator (fur) has evolved additional regulatory functions not seen in other bacteria; it can repress and activate different groups of genes in both its iron-bound and apo forms. because little is understood about the process of apo-fur repression and because only two apo-fur-repressed genes (pfr and sodb) have previously been identified, we sought to expand our understanding of this type of regulation. utilizing published genomic studies, we selected t ...201324097951
biochemical activities of streptococcus pneumoniae serotype 2 capsular glycosyltransferases and significance of suppressor mutations affecting the initiating glycosyltransferase cps2e.the capsular polysaccharide (cps) is essential for streptococcus pneumoniae virulence. its synthesis requires multiple enzymes, and defects that block completion of the pathway can be lethal in the absence of secondary suppressor mutations. in this study, we examined the functions of three capsular glycosyltransferases (cps2f, cps2g, and cps2i) involved in serotype 2 cps synthesis, whose deletions select for secondary mutations. we demonstrate that cps2f is a rhamnosyltransferase that catalyzes ...201324097952
fucosylated but not sialylated milk oligosaccharides diminish colon motor contractions.human milk oligosaccharides (hmo) are being studied by different groups exploring a broad range of potential beneficial effects to the breastfed infant. many of these effects have been attributed to a growth promotion effect on certain gut organisms such as bifidobacteria. additionally, evidence indicates that hmo are able to directly promote positive changes in gut epithelium and immune responses under certain conditions. this study utilizes a standardized ex vivo murine colon preparation to ex ...201324098451
pathogenomic inference of virulence-associated genes in leptospira interrogans.leptospirosis is a globally important, neglected zoonotic infection caused by spirochetes of the genus leptospira. since genetic transformation remains technically limited for pathogenic leptospira, a systems biology pathogenomic approach was used to infer leptospiral virulence genes by whole genome comparison of culture-attenuated leptospira interrogans serovar lai with its virulent, isogenic parent. among the 11 pathogen-specific protein-coding genes in which non-synonymous mutations were foun ...201324098822
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
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