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cardiovascular disease after escherichia coli o157:h7 gastroenteritis.escherichia coli o157:h7 is one cause of acute bacterial gastroenteritis, which can be devastating in outbreak situations. we studied the risk of cardiovascular disease following such an outbreak in walkerton, ontario, in may 2000.201323166291
structural characterization of the highly cyclized lantibiotic paenicidin a via a partial desulfurization/reduction strategy.lantibiotics are ribosomally synthesized antimicrobial peptides produced by bacteria that are increasingly of interest for food preservation and possible therapeutic uses. these peptides are extensively post-translationally modified, and are characterized by lanthionine and methyllanthionine thioether cross-links. paenibacillus polymyxa nrrl b-30509 was found to produce polymyxins and tridecaptins, in addition to a novel lantibiotic termed paenicidin a. a bacteriocin termed srcam 602 previously ...201223167271
effects of the campylobacter jejuni cjie1 prophage homologs on adherence and invasion in culture, patient symptoms, and source of infection.prophages of enteric bacteria are frequently of key importance for the biology, virulence, or host adaptation of their host. some c. jejuni isolates carry homologs of the cjie1 (cmlp 1) prophage that carry cargo genes potentially involved in virulence. possible role(s) of cjie1 homologs in the biology and virulence of c. jejuni were therefore investigated by using in vitro cell culture assays and by assessing the association of c. jejuni isolates with and without these prophages with patients' s ...201223167543
identification of an atypical zinc metalloproteinase, zmpc, from an epidemic conjunctivitis-causing strain of streptococcus pneumoniae.streptococcus pneumoniae is a pathogen associated with a range of invasive and noninvasive infections. despite the identification of the majority of virulence factors expressed by s. pneumoniae, knowledge of the strategies used by this bacterium to trigger infections, especially those originating at wet-surfaced epithelia, remains limited. in this regard, we recently reported a mechanism used by a nonencapsulated, epidemic conjunctivitis-causing strain of s. pneumoniae (strain sp168) to gain acc ...201223168398
identification of an atypical zinc metalloproteinase, zmpc, from an epidemic conjunctivitis-causing strain of streptococcus pneumoniae.streptococcus pneumoniae is a pathogen associated with a range of invasive and noninvasive infections. despite the identification of the majority of virulence factors expressed by s. pneumoniae, knowledge of the strategies used by this bacterium to trigger infections, especially those originating at wet-surfaced epithelia, remains limited. in this regard, we recently reported a mechanism used by a nonencapsulated, epidemic conjunctivitis-causing strain of s. pneumoniae (strain sp168) to gain acc ...201223168398
the global enteric multicenter study (gems): impetus, rationale, and genesis.diarrheal disease remains one of the top 2 causes of young child mortality in the developing world. whereas improvements in water/sanitation infrastructure and hygiene can diminish transmission of enteric pathogens, vaccines can also hasten the decline of diarrheal disease morbidity and mortality. from 1980 through approximately 2004, various case/control and small cohort studies were undertaken to address the etiology of pediatric diarrhea in developing countries. many studies had methodologica ...201223169934
diagnostic microbiologic methods in the gems-1 case/control study.to understand the etiology of moderate-to-severe diarrhea among children in high mortality areas of sub-saharan africa and south asia, we performed a comprehensive case/control study of children aged <5 years at 7 sites. each site employed an identical case/control study design and each utilized a uniform comprehensive set of microbiological assays to identify the likely bacterial, viral and protozoal etiologies. the selected assays effected a balanced consideration of cost, robustness and perfo ...201223169941
factors that explain excretion of enteric pathogens by persons without diarrhea.excretion of enteropathogens by subjects without diarrhea influences our appreciation of the role of these pathogens as etiologic agents. characteristics of the pathogens and host and environmental factors help explain asymptomatic excretion of diarrheal pathogens by persons without diarrhea. after causing acute diarrhea followed by clinical recovery, some enteropathogens are excreted asymptomatically for many weeks. thus, in a prevalence survey of persons without diarrhea, some may be excreting ...201223169942
laboratory diagnostic challenges in case/control studies of diarrhea in developing countries.case/control studies of acute infectious diarrhea require accurate and dependable laboratory tests to detect pathogens in samples from both symptomatic patients and healthy control subjects. the methods used to detect these pathogens have usually been evaluated on patient samples only, and their performance on samples from control subjects is mostly unknown. because many pathogens occur at a high overall frequency in developing countries and thus may be present in a notable proportion of control ...201223169943
the protein interaction network of a taxis signal transduction system in a halophilic archaeon.the taxis signaling system of the extreme halophilic archaeon halobacterium (hbt.) salinarum differs in several aspects from its model bacterial counterparts escherichia coli and bacillus subtilis. we studied the protein interactions in the hbt. salinarum taxis signaling system to gain an understanding of its structure, to gain knowledge about its known components and to search for new members.201223171228
graphalignment: bayesian pairwise alignment of biological networks.with increased experimental availability and accuracy of bio-molecular networks, tools for their comparative and evolutionary analysis are needed. a key component for such studies is the alignment of networks.201223171476
siglec-7 specifically recognizes campylobacter jejuni strains associated with oculomotor weakness in guillain-barré syndrome and miller fisher syndrome.due to molecular mimicry, campylobacter jejuni lipo-oligosaccharides can induce a cross-reactive antibody response to nerve gangliosides, which leads to guillain-barré syndrome (gbs). cross-reactive antibodies to ganglioside gq1b are strongly associated with oculomotor weakness in gbs and its variant, miller fisher syndrome (mfs). antigen recognition is a crucial first step in the induction of a cross-reactive antibody response, and it has been shown that gq1b-like epitopes expressed on the surf ...201323173866
occurrence of pathogens in wild rodents caught on swedish pig and chicken farms.a total of 207 wild rodents were caught on nine pig farms, five chicken farms and five non-farm locations in sweden and surveyed for a selection of bacteria, parasites and viruses. lawsonia intracellularia and pathogenic yersinia enterocolitica were only detected in rodents on pig farms (9% and 8% prevalence, respectively) which indicate that these agents are more likely to be transmitted to rodents from pigs or the environment on infected farms. brachyspira hyodysenteriae (1%), brachyspira inte ...201323174339
an unusual case of parinaud's syndrome.a 25-year-old man presented with blurred vision, headache and dizziness. on questioning, there was also a history of a preceding diarrhoeal illness. initial investigations were normal. however, after a week, he represented with a parinaud's syndrome. in view of the preceding diarrhoea, the transient unsteadiness and the areflexia on examination, anti-gq1b antibodies were requested. the resulting titre was positive confirming the suspected diagnosis of miller fisher syndrome. he responded to intr ...201223175005
rapid detection of campylobacter antigen by enzyme immunoassay leads to increased positivity rates.campylobacter antigen detection by enzyme immunoassay (eia) provides rapid results compared to traditional culture. however, concern exists regarding specificity. verification studies of an eia compared to culture revealed a positive predictive value (ppv) of 91%, whereas ppv fell to 42% during routine diagnostic testing. we suggest all positive eia results be confirmed via culture.201323175262
comparison of three different methods for detection of shiga toxin-producing escherichia coli in a tertiary pediatric care center.shiga toxin-producing escherichia coli (stec) is a well-known cause of sporadic and epidemic food-borne gastroenteritis. a low infectious dose, approximately 10 microorganisms, is sufficient to cause disease that may lead to hemolytic-uremic syndrome. the objective of this study was to compare the performances of an in-house real-time pcr, a commercial enzyme immunoassay (eia) (premier ehec; meridian bioscience), and culture on sorbitol macconkey agar for the detection of stec in a tertiary care ...201323175264
a laboratory-developed taqman array card for simultaneous detection of 19 enteropathogens.the taqman array card (tac) system is a 384-well singleplex real-time pcr format that has been used to detect multiple infection targets. here we developed an enteric taqman array card to detect 19 enteropathogens, including viruses (adenovirus, astrovirus, norovirus gii, rotavirus, and sapovirus), bacteria (campylobacter jejuni/c. coli, clostridium difficile, salmonella, vibrio cholerae, diarrheagenic escherichia coli strains including enteroaggregative e. coli [eaec], enterotoxigenic e. coli [ ...201323175269
design and data analysis of experimental trials to test vaccine candidates against zoonotic pathogens in animals: the case of a clinical trial against campylobacter in broilers.the development of effective vaccines against zoonotic pathogens represents a priority in public health protection programs. the design of clinical trials and appropriate data analysis of the experiments results are crucial for the assessment of vaccine effectiveness. this manuscript reviews important issues related to the assessment of the effectiveness of vaccines designed to obtain a quantitative reduction of the pathogen in animals or animal products. an effective vaccine will reduce the ris ...201223176651
phosphatidylinositol 3-kinase-γ signaling promotes campylobacter jejuni-induced colitis through neutrophil recruitment in mice.crypt abscesses caused by excessive neutrophil accumulation are prominent features of human campylobacteriosis and its associated pathology. the molecular and cellular events responsible for this pathological situation are currently unknown. we investigated the contribution of pi3k-γ signaling in campylobacter jejuni-induced neutrophil accumulation and intestinal inflammation. germ-free and specific pathogen-free il10(-/-) and germ-free il10(-/-);rag2(-/-) mice were infected with c. jejuni (10(9 ...201223180818
phosphatidylinositol 3-kinase-γ signaling promotes campylobacter jejuni-induced colitis through neutrophil recruitment in mice.crypt abscesses caused by excessive neutrophil accumulation are prominent features of human campylobacteriosis and its associated pathology. the molecular and cellular events responsible for this pathological situation are currently unknown. we investigated the contribution of pi3k-γ signaling in campylobacter jejuni-induced neutrophil accumulation and intestinal inflammation. germ-free and specific pathogen-free il10(-/-) and germ-free il10(-/-);rag2(-/-) mice were infected with c. jejuni (10(9 ...201223180818
health-promoting properties of lactobacillus helveticus.lactobacillus helveticus is an important industrial thermophilic starter that is predominantly employed in the fermentation of milk for the manufacture of several cheeses. in addition to its technological importance, a growing body of scientific evidence shows that strains belonging to the l. helveticus species have health-promoting properties. in this review, we synthesize the results of numerous primary literature papers concerning the ability of l. helveticus strains to positively influence h ...201223181058
eptc of campylobacter jejuni mediates phenotypes involved in host interactions and virulence.campylobacter jejuni is a natural commensal of the avian intestinal tract. however, the bacterium is also the leading cause of acute bacterial diarrhea worldwide and is implicated in development of guillain-barré syndrome. like many bacterial pathogens, c. jejuni assembles complex surface structures that interface with the surrounding environment and are involved in pathogenesis. recent work in c. jejuni identified a gene encoding a novel phosphoethanolamine (petn) transferase, eptc (cj0256), th ...201323184526
a single n-acetylgalactosamine residue at threonine 106 modifies the dynamics and structure of interferon α2a around the glycosylation site.enzymatic addition of galnac to isotopically labeled ifnα2a produced in escherichia coli yielded the o-linked glycoprotein galnacα-[(13)c,(15)n]ifnα2a. the three-dimensional structure of galnacα-ifnα2a has been determined in solution by nmr spectroscopy at high resolution. proton-nitrogen heteronuclear overhauser enhancement measurements revealed that the addition of a single monosaccharide unit at thr-106 significantly slowed motions of the glycosylation loop on the nanosecond time scale. subse ...201223184955
a single n-acetylgalactosamine residue at threonine 106 modifies the dynamics and structure of interferon α2a around the glycosylation site.enzymatic addition of galnac to isotopically labeled ifnα2a produced in escherichia coli yielded the o-linked glycoprotein galnacα-[(13)c,(15)n]ifnα2a. the three-dimensional structure of galnacα-ifnα2a has been determined in solution by nmr spectroscopy at high resolution. proton-nitrogen heteronuclear overhauser enhancement measurements revealed that the addition of a single monosaccharide unit at thr-106 significantly slowed motions of the glycosylation loop on the nanosecond time scale. subse ...201223184955
the evolution of mutualism in gut microbiota via host epithelial selection.the human gut harbours a large and genetically diverse population of symbiotic microbes that both feed and protect the host. evolutionary theory, however, predicts that such genetic diversity can destabilise mutualistic partnerships. how then can the mutualism of the human microbiota be explained? here we develop an individual-based model of host-associated microbial communities. we first demonstrate the fundamental problem faced by a host: the presence of a genetically diverse microbiota leads ...201223185130
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
phylogenetic identification of bacterial mazf toxin protein motifs among probiotic strains and foodborne pathogens and potential implications of engineered probiotic intervention in food. 201223186337
norovirus gastroenteritis in immunocompromised patients. 201223190223
a mutagenesis method for the addition and deletion of highly repetitive dna regions: the paradigm of epiya motifs in the caga gene of helicobacter pylori.caga protein of western origin helicobacter pylori isolates contains at its carboxyl-terminal end repeating types of epiya motifs, depending on the surrounding sequence, which dictate hierarchic tyrosine phosphorylation. to produce, in an isogenic background, mutant strains expressing caga protein with variable numbers of epiya-c terminal motifs, we have adopted a mutagenesis assay using a megaprimer approach.201323190444
miller fisher syndrome mimicking ocular myasthenia gravis.purpose.: miller fisher syndrome (mfs) is a rare immune-mediated neuropathy that commonly presents with diplopia after the acute onset of complete bilateral external ophthalmoplegia. ophthalmoplegia is often accompanied by other neurological deficits such as ataxia and areflexia that characterize mfs. although mfs is a clinical diagnosis, serological confirmation is possible by identifying the anti-gq1b antibody found in most of the affected patients. we report a patient with mfs who presented w ...201223190719
structure determination of lpxa from the lipopolysaccharide-synthesis pathway of acinetobacter baumannii.acinetobacter baumannii is a gram-negative pathogenic bacterium which is resistant to most currently available antibiotics and that poses a significant health threat to hospital patients. lpxa is a key enzyme in the biosynthetic pathway of the lipopolysaccharides that are components of the bacterial outer membrane. it is a potential target for antibacterial agents that might be used to fight a. baumannii infections. this paper describes the structure determination of the apo form of lpxa in spac ...201223192027
management of acute diarrhea in emergency room.acute diarrhea is the second leading cause of under-five mortality in india. it is defined as the passage of frequent watery stools (>3/24 h). recent change in consistency of stools is more important than frequency. acute diarrhea is caused by variety of viral, bacterial and parasitic agents. the common ones are: rotavirus, e. coli, shigella, cholera, and salmonella. campylobacter jejuni, giardia and e. histolytica are also not uncommon. the most important concern in management of acute diarrhea ...201323192407
prevalence of the main food-borne pathogens in retail food under the national food surveillance system in japan.the national food surveillance system in japan was formed in 1998 to monitor the contamination of retail foods with bacterial pathogens. approximately 2000-3000 samples were tested annually, and the data from food categories that had more than 400 samples collected during 1998-2008 were analysed. with regard to meat, the frequency of positive samples for salmonella in chicken for raw consumption and ground chicken was 12.7% and 33.5%, respectively. moreover, shiga toxin-producing escherichia col ...201323199079
treatment of diarrhoea in rural african communities: an overview of measures to maximise the medicinal potentials of indigenous plants.diarrhoea is a major cause of morbidity and mortality in rural communities in africa, particularly in children under the age of five. this calls for the development of cost effective alternative strategies such as the use of herbal drugs in the treatment of diarrhoea in these communities. expenses associated with the use of orthodox medicines have generated renewed interest and reliance on indigenous medicinal plants in the treatment and management of diarrhoeal infections in rural communities. ...201223202823
enterococci in the environment.enterococci are common, commensal members of gut communities in mammals and birds, yet they are also opportunistic pathogens that cause millions of human and animal infections annually. because they are shed in human and animal feces, are readily culturable, and predict human health risks from exposure to polluted recreational waters, they are used as surrogates for waterborne pathogens and as fecal indicator bacteria (fib) in research and in water quality testing throughout the world. evidence ...201223204362
evidence for phenotypic plasticity among multihost campylobacter jejuni and c. coli lineages, obtained using ribosomal multilocus sequence typing and raman spectroscopy.closely related bacterial isolates can display divergent phenotypes. this can limit the usefulness of phylogenetic studies for understanding bacterial ecology and evolution. here, we compare phenotyping based on raman spectrometric analysis of cellular composition to phylogenetic classification by ribosomal multilocus sequence typing (rmlst) in 108 isolates of the zoonotic pathogens campylobacter jejuni and c. coli. automatic relevance determination (ard) was used to identify informative peaks i ...201323204423
guillain-barré syndrome in two patients with respiratory failure and a review of the japanese literature.we described two patients with guillain-barré syndrome and respiratory failure with or without mechanical ventilation. case 1 was a 44-year-old man who treated as pneumonia under mechanical ventilation for a month and transferred to our hospital with unsuccessful weaning trials because of phrenic nerve palsy. case 2 was a 74-year-old man who presented with aspiration pneumonia because of bulbar palsy. the present two cases with review of the japanese literature showed that antecedent infection w ...201223205285
active site comparisons and catalytic mechanisms of the hot dog superfamily. 201223205964
active site comparisons and catalytic mechanisms of the hot dog superfamily. 201223205964
evaluation of the positive predictive value of a rapid immunochromatographic test to detect campylobacter in stools.the recently developed rapid immunochromatographic tests (ict) have the potential to provide a quick and easy diagnosis of campylobacter enteritis in comparison to culture. in a previous study we found them sensitive but lacking in specificity. the aim of the present study was to focus on the problem of specificity and determine the positive predictive value (ppv) of a positive result of the immunocard stat! campy (meridian bioscience, cincinnati, oh, usa). for this purpose, the stools positive ...201223206554
prevalence and characterization of foodborne pathogens in dairy cattle in the eastern part of japan.to investigate the prevalence and characterization of foodborne pathogens [campylobacter spp., shiga toxin-producing escherichia coli (stec), listeria monocytogenes and salmonella spp.] in dairy cows, rectal content grab samples were collected from 250 dairy cows reared on 25 dairy farms in eastern japan from december 2010 through february 2011. campylobacter jejuni was isolated from 106 (42%) cows on 23 (92%) farms, stec o157 from three cows on one farm, l. monocytogenes from three cows on anot ...201323208291
genome sequence of moraxella catarrhalis rh4, an isolate of seroresistant lineage.here we report the annotated genome sequence of moraxella catarrhalis strain rh4, a seroresistant-lineage strain isolated from the blood of an infected patient. this genome sequence will allow us to gain further insight into the genetic diversity of clinical m. catarrhalis isolates and will facilitate study of m. catarrhalis pathogenesis.201223209224
comparative genotypic and antimicrobial susceptibility analysis of zoonotic campylobacter species isolated from broilers in a nationwide survey, portugal.campylobacter is a major cause of human foodborne disease worldwide and has been associated with the consumption of contaminated poultry. the prevalence of campylobacter species in broiler flocks from more than 200 producers widespread in mainland portugal was assessed in 2008 in response to commission decision 2007/516/ec. campylobacter isolates were obtained from 83.3% of 424 pooled cecal samples, with a higher prevalence of campylobacter coli (61.2%) than campylobacter jejuni (38.8%). restric ...201223212005
in vitro antibacterial and time-kill evaluation of the erythrina caffra thunb. extract against bacteria associated with diarrhoea.the antibacterial activities of stem bark ethanolic extract of erythrina caffra thunb. against bacteria in diarrhoea was determined in vitro by the agar diffusion and dilution, macrobroth dilution, and time-kill assay methods. the result showed that the extract produced inhibition zones ranging between 15 ± 1.0 mm and 23 ± 1.0 mm, and the bacteria were susceptible at concentrations ranging between ≤100 and ≤1000 μg/ml. while the mics of the extract ranged between 39.1 and 625 μg/ml, and the mbcs ...201223213297
acute diarrhea among military recruits.there is a considerable amount of speculations concerning the presence of symptoms mainly diarrhea in various bacterial and parasitic infections. among a youth group with acute diarrhea, many bacterial and parasitic diseases were detected. the bacterial causes were campylobacter jejuni, shigella sp. entero-toxigenic, escherichia coli, salmonella sp. and aeromonas hydrophila. the parasitic causes were cryptosporidium parvum, entamoeba histolytica, giardia lamblia and strongyloides stercoralis. ma ...201223214210
experimental evidence validating the computational inference of functional associations from gene fusion events: a critical survey.more than a decade ago, a number of methods were proposed for the inference of protein interactions, using whole-genome information from gene clusters, gene fusions and phylogenetic profiles. this structural and evolutionary view of entire genomes has provided a valuable approach for the functional characterization of proteins, especially those without sequence similarity to proteins of known function. furthermore, this view has raised the real possibility to detect functional associations of ge ...201223220349
experimental evidence validating the computational inference of functional associations from gene fusion events: a critical survey.more than a decade ago, a number of methods were proposed for the inference of protein interactions, using whole-genome information from gene clusters, gene fusions and phylogenetic profiles. this structural and evolutionary view of entire genomes has provided a valuable approach for the functional characterization of proteins, especially those without sequence similarity to proteins of known function. furthermore, this view has raised the real possibility to detect functional associations of ge ...201223220349
unique gangliosides synthesized in vitro by sialyltransferases from marine bacteria and their characterization: ganglioside synthesis by bacterial sialyltransferases.on the basis of the results outlined in our previous report, bacterial sialyltransferases (st) from marine sources were further characterized using glycosphingolipids (gsl), especially ganglio-series gsls, based on the enzymatic characteristics and kinetic parameters obtained by line weaver-burk plots. among them, ga1 and ga2 were found to be good substrates for these unique sts. thus, new gangliosides synthesized by α2-3 and α2-6sts were structurally characterized by several analytical procedur ...201323220479
prevalence and antimicrobial resistance of campylobacter isolates from beef cattle and pigs in japan.rectal contents of beef cattle and pigs were collected between october 2010 and february 2011 in japan. campylobacter jejuni were isolated from 36.0% (90/250) of beef cattle from 88.0% (22/25) of beef farms. c. coli were isolated from 3.6% (9/250) of beef cattle from 16.0% (4/25) of beef farms and from 42.4% (106/250) of pigs from all 25 pig farms. as to enrofloxacin, 40.0% (36/90) of c. jejuni isolates and 66.7% (6/9) of c. coli isolates from beef cattle and 44.3% (47/106) of c. coli isolates f ...201323220905
molecular pathology of lymphoma.ocular lymphomas can be divided into intraocular lymphomas and ocular adnexal lymphomas. the vitreoretinal lymphoma-usually a diffuse large b-cell lymphoma (dlbcl) of high-grade malignancy-is the most common lymphoid malignancy arising in the eye, while the extranodal marginal zone b-cell lymphoma (emzl), an indolent often recurrent tumour, occurs most frequently in the ocular adnexal tissue. the two lymphoma subtypes differ significantly in their clinical presentation, subsequent course and out ...201223222560
molecular pathology of lymphoma.ocular lymphomas can be divided into intraocular lymphomas and ocular adnexal lymphomas. the vitreoretinal lymphoma-usually a diffuse large b-cell lymphoma (dlbcl) of high-grade malignancy-is the most common lymphoid malignancy arising in the eye, while the extranodal marginal zone b-cell lymphoma (emzl), an indolent often recurrent tumour, occurs most frequently in the ocular adnexal tissue. the two lymphoma subtypes differ significantly in their clinical presentation, subsequent course and out ...201223222560
class iia bacteriocins: diversity and new developments.class iia bacteriocins are heat-stable, unmodified peptides with a conserved amino acids sequence ygngv on their n-terminal domains, and have received much attention due to their generally recognized as safe (gras) status, their high biological activity, and their excellent heat stability. they are promising and attractive agents that could function as biopreservatives in the food industry. this review summarizes the new developments in the area of class iia bacteriocins and aims to provide upto ...201223222636
architecture of the major component of the type iii secretion system export apparatus.type iii secretion systems (t3sss) are bacterial membrane-embedded nanomachines designed to export specifically targeted proteins from the bacterial cytoplasm. secretion through t3ss is governed by a subset of inner membrane proteins termed the 'export apparatus'. we show that a key member of the shigella flexneri export apparatus, mxia, assembles into a ring essential for secretion in vivo. the ring-forming interfaces are well-conserved in both nonflagellar and flagellar homologs, implying that ...201223222644
architecture of the major component of the type iii secretion system export apparatus.type iii secretion systems (t3sss) are bacterial membrane-embedded nanomachines designed to export specifically targeted proteins from the bacterial cytoplasm. secretion through t3ss is governed by a subset of inner membrane proteins termed the 'export apparatus'. we show that a key member of the shigella flexneri export apparatus, mxia, assembles into a ring essential for secretion in vivo. the ring-forming interfaces are well-conserved in both nonflagellar and flagellar homologs, implying that ...201223222644
surveillance for enteric pathogens in a case-control study of acute diarrhea in western kenya.acute diarrhea remains a major public health problem in east african nations such as kenya. surveillance for a broad range of enteric pathogens is necessary to accurately predict the frequency of pathogens and potential changes in antibiotic resistance patterns.201323222955
promising new assays and technologies for the diagnosis and management of infectious diseases.in the first decade of the 21st century, we have seen the completion of the human genome project and marked progress in the human microbiome project. the vast amount of data generated from these efforts combined with advances in molecular and biomedical technologies have led to the development of a multitude of assays and technologies that may be useful in the diagnosis and management of infectious diseases. here, we identify several new assays and technologies that have recently come into clini ...201223223587
promising new assays and technologies for the diagnosis and management of infectious diseases.in the first decade of the 21st century, we have seen the completion of the human genome project and marked progress in the human microbiome project. the vast amount of data generated from these efforts combined with advances in molecular and biomedical technologies have led to the development of a multitude of assays and technologies that may be useful in the diagnosis and management of infectious diseases. here, we identify several new assays and technologies that have recently come into clini ...201223223587
encephalitis and antibodies to dipeptidyl-peptidase-like protein-6, a subunit of kv4.2 potassium channels.to report a novel cell surface autoantigen of encephalitis that is a critical regulatory subunit of the kv4.2 potassium channels.201223225603
encephalitis and antibodies to dipeptidyl-peptidase-like protein-6, a subunit of kv4.2 potassium channels.to report a novel cell surface autoantigen of encephalitis that is a critical regulatory subunit of the kv4.2 potassium channels.201223225603
microbial pathways in colonic sulfur metabolism and links with health and disease.sulfur is both crucial to life and a potential threat to health. while colonic sulfur metabolism mediated by eukaryotic cells is relatively well studied, much less is known about sulfur metabolism within gastrointestinal microbes. sulfated compounds in the colon are either of inorganic (e.g., sulfates, sulfites) or organic (e.g., dietary amino acids and host mucins) origin. the most extensively studied of the microbes involved in colonic sulfur metabolism are the sulfate-reducing bacteria (srb), ...201223226130
contribution of amino acid catabolism to the tissue specific persistence of campylobacter jejuni in a murine colonization model.campylobacter jejuni is a major cause of food-borne disease in industrialized countries. carbohydrate utilization by c. jejuni is severely restricted, and knowledge about which substrates fuel c. jejuni infection and growth is limited. some amino acids have been shown to serve as carbon sources both in vitro and in vivo. in the present study we investigated the contribution of serine and proline catabolism to the invitro and invivo growth of c. jejuni 81-176. we confirmed that the serine transpo ...201223226358
sinorhizobium meliloti sigma factors rpoe1 and rpoe4 are activated in stationary phase in response to sulfite.rhizobia are soil bacteria able to establish a nitrogen-fixing symbiosis with legume plants. both in soil and in planta, rhizobia spend non-growing periods resembling the stationary phase of in vitro-cultured bacteria. the primary objective of this work was to better characterize gene regulation in this biologically relevant growth stage in sinorhizobium meliloti. by a tap-tag/mass spectrometry approach, we identified five sigma factors co-purifying with the rna polymerase in stationary phase: t ...201223226379
synergistic action of gentamicin and bacteriophage in a continuous culture population of staphylococcus aureus.with the increasing frequency of antibiotic resistance and the decreasing frequency of new antibiotics entering the market, interest has returned to developing bacteriophage as a therapeutic agent. acceptance of phage therapy, however, is limited by the unknown pharmacodynamics of a replicating agent, as well as the potential for the evolution of resistant bacteria. one way to overcome some of these limitations is to incorporate phage and antibiotics into a dual therapy regimen; however, this in ...201223226451
specific synthesis of neurostatin and gangliosides o-acetylated in the outer sialic acids using a sialate transferase.gangliosides are sialic acid containing glycosphingolipids, commonly found on the outer leaflet of the plasma membrane. o-acetylation of sialic acid hydroxyl groups is one of the most common modifications in gangliosides. studies on the biological activity of o-acetylated gangliosides have been limited by their scarcity in nature. this comparatively small change in ganglioside structure causes major changes in their physiological properties. when the ganglioside gd1b was o-acetylated in the oute ...201223226505
innate immune recognition of flagellin limits systemic persistence of brucella.brucella are facultative intracellular bacteria that cause chronic infections by limiting innate immune recognition. it is currently unknown whether brucella flic flagellin, the monomeric subunit of flagellar filament, is sensed by the host during infection. here, we used two mutants of brucella melitensis, either lacking or overexpressing flagellin, to show that flic hinders bacterial replication in vivo. the use of cells and mice genetically deficient for different components of inflammasomes ...201323227931
microbial modulation of host immunity with the small molecule phosphorylcholine.all microorganisms dependent on persistence in a host for survival rely on either hiding from or modulating host responses to infection. the small molecule phosphorylcholine, or choline phosphate (chop), is used for both of these purposes by a wide array of bacterial and parasitic microbes. while the mechanisms underlying chop acquisition and expression are diverse, a unifying theme is the use of chop to reduce the immune response to infection, creating an advantage for chop-expressing microorga ...201323230294
intracellularly induced cyclophilins play an important role in stress adaptation and virulence of brucella abortus.brucella is an intracellular bacterial pathogen that causes the worldwide zoonotic disease brucellosis. brucella virulence relies on its ability to transition to an intracellular lifestyle within host cells. thus, this pathogen must sense its intracellular localization and then reprogram gene expression for survival within the host cell. a comparative proteomic investigation was performed to identify differentially expressed proteins potentially relevant for brucella intracellular adaptation. tw ...201323230297
carbon storage regulator a contributes to the virulence of haemophilus ducreyi in humans by multiple mechanisms.the carbon storage regulator a (csra) controls a wide variety of bacterial processes, including metabolism, adherence, stress responses, and virulence. haemophilus ducreyi, the causative agent of chancroid, harbors a homolog of csra. here, we generated an unmarked, in-frame deletion mutant of csra to assess its contribution to h. ducreyi pathogenesis. in human inoculation experiments, the csra mutant was partially attenuated for pustule formation compared to its parent. deletion of csra resulted ...201323230298
screening for lactic acid bacteria capable of inhibiting campylobacter jejuni in in vitro simulations of the broiler chicken caecal environment.thermotolerant campylobacter spp., specifically campylobacter jejuni and campylobacter coli, are the most common bacterial causes of human gastroenteritis in developed countries. consumption of improperly prepared poultry products and cross contamination are among the main causes of human campylobacteriosis. the aim of this study was to identify lactic acid bacterial (lab) strains capable of inhibiting c. jejuni growth in initial in vitro trials ('spot-on-lawn' method), as well as in batch ferme ...201223234730
molecular characterization and genotypic antimicrobial resistance analysis of campylobacter jejuni and campylobacter coli isolated from broiler flocks in northern italy.genetic variability and genotypic antimicrobial resistance (amr) of campylobacter jejuni and campylobacter coli from commercial broiler farms were investigated in this study. campylobacter isolates were genetically characterized by random amplified polymorphic dna (rapd)-polymerase chain reaction (pcr) and flaa-svr and flab-svr sequence-based typing. eight rapd types were identified in c. jejuni and three in c. coli, while 16 fla profiles were detected among all isolates. further, 13 flaa-svr an ...201223237371
effect of selected types of beer on bacteria of the genus arcobacter.the genus arcobacter is related to the well-known human pathogen, campylobacter jejuni, and has been linked to human diseases. in this study, the survival of arcobacter spp. in various concentrations of ethanol, in various samples of beers, and in a model stomach has been investigated. for most of these bacteria, a concentration of 10 % ethanol was determined to be the minimum inhibitory concentration. the fact that these organisms are able to survive under these conditions may have an impact in ...201323238953
investigation of motility and biofilm formation by intestinal campylobacter concisus strains.motility helps many pathogens swim through the highly viscous intestinal mucus. given the differing outcomes of campylobacter concisus infection, the motility of eight c. concisus strains isolated from patients with crohn's disease (n=3), acute (n=3) and chronic (n=1) gastroenteritis and a healthy control (n=1) were compared. following growth on solid or liquid media the eight strains formed two groups; however, the type of growth medium did not affect motility. in contrast, following growth in ...201223241133
miller fisher syndrome linked to norovirus infection.this is a case of miller fisher syndrome (mfs) linked to the norovirus syndrome. to our best knowledge, this is the first case report describing mfs associated with norovirus infection.201223242098
antimicrobial efflux pumps and mycobacterium tuberculosis drug tolerance: evolutionary considerations.the need for lengthy treatment to cure tuberculosis stems from phenotypic drug resistance, also known as drug tolerance, which has been previously attributed to slowed bacterial growth in vivo. we discuss recent findings that challenge this model and instead implicate macrophage-induced mycobacterial efflux pumps in antimicrobial tolerance. although mycobacterial efflux pumps may have originally served to protect against environmental toxins, in the pathogenic mycobacteria, they appear to have b ...201323242857
in vivo broiler experiments to assess anti-campylobacter jejuni activity of a live enterococcus faecalis strain.bacterial gastroenteritis caused by thermotolerant campylobacter species, mainly campylobacter jejuni, has been the most reported zoonotic disease in many developed countries in recent years. reducing campylobacter shedding on the farm could result in a reduction of the number of campylobacteriosis cases. in 2 independent broiler seeder experiments, in which broiler chickens were orally inoculated with 2 amounts of enterococcus faecalis mb 5259, we established whether a live e. faecalis strain w ...201323243257
cell sorting enriches escherichia coli mutants that rely on peptidoglycan endopeptidases to suppress highly aberrant morphologies.bacterial morphology imparts physiological advantages to cells in different environments and, judging by the fidelity with which shape is passed to daughter cells, is a tightly regulated characteristic. surprisingly, only in the past 10 to 15 years has significant headway been made in identifying the mechanisms by which cells create and maintain particular shapes. one reason for this is that the relevant discoveries have relied heavily on the arduous, somewhat subjective process of manual micros ...201323243305
induction of cytokines in different organs after intranasal inoculation of campylobacter jejuni in mice. 201223244595
l-asparaginase ii produced by salmonella typhimurium inhibits t cell responses and mediates virulence.salmonella enterica serovar typhimurium avoids clearance by the host immune system by suppressing t cell responses; however, the mechanisms that mediate this immunosuppression remain unknown. we show that s. typhimurium inhibit t cell responses by producing l-asparaginase ii, which catalyzes the hydrolysis of l-asparagine to aspartic acid and ammonia. l-asparaginase ii is necessary and sufficient to suppress t cell blastogenesis, cytokine production, and proliferation and to downmodulate express ...201223245323
[traveller's diarrhea: epidemiology, clinical practice guideline for the prevention and treatment].bacterial causes are predominant: enterotoxigenic (etec) ou enteroadherent escherichia coli, salmonella sp., shigella sp., campylobacter jejuni, acrobacter sp., enterotoxigenic bacteroïdes fragilis. prevention relies on the hand and food hygiene standards (heat-cooked meals). watery diarrhea (toxigenic enterocolitis) is the most frequent clinical presentation associated with a risk of dehydration; the body temperature is normal except in cases of severe dehydration. less frequent are invasive en ...201323246203
the polysaccharide capsule of campylobacter jejuni modulates the host immune response.campylobacter jejuni is a major cause of bacterial diarrheal disease worldwide. the organism is characterized by a diversity of polysaccharide structures, including a polysaccharide capsule. most c. jejuni capsules are known to be decorated nonstoichiometrically with methyl phosphoramidate (meopn). the capsule of c. jejuni 81-176 has been shown to be required for serum resistance, but here we show that an encapsulated mutant lacking the meopn modification, an mpnc mutant, was equally as sensitiv ...201323250948
guillain-barré syndrome associated with primary parvovirus b19 infection in an hiv-1-infected patient.parvovirus b19 (b19v) infection has rarely been reported as responsible for guillain-barré syndrome (gbs). we present the case of a 63-year-old man with aids who presented with rapidly progressing weakness of his inferior limbs and a newly appeared pancytopenia. csf examination and electromyography were characteristic for gbs. very high csf and serum b19v dna concentrations were present, in the absence of igg or igm against b19v. the neurologic and hematologic abnormalities improved after a 5-da ...201223251163
unique features of the motility and structures in the flagellate polar region of campylobacter jejuni and other species: an electron microscopic study.similarly to helicobacter pylori but unlike vibrio cholerae o1/o139, campylobacter jejuni is non-motile at 20°c but highly motile at ≥37°c. the bacterium c. jejuni has one of the highest swimming speeds reported (>100 μm/s), especially at 42°c. straight and spiral bacterial shapes share the same motility. c. jejuni has a unique structure in the flagellate polar region, which is characterized by a cup-like structure (beneath the inner membrane), a funnel shape (opening onto the polar surface) and ...201323252968
multivalent glycoconjugates as anti-pathogenic agents.multivalency plays a major role in biological processes and particularly in the relationship between pathogenic microorganisms and their host that involves protein-glycan recognition. these interactions occur during the first steps of infection, for specific recognition between host and bacteria, but also at different stages of the immune response. the search for high-affinity ligands for studying such interactions involves the combination of carbohydrate head groups with different scaffolds and ...201223254759
multivalent glycoconjugates as anti-pathogenic agents.multivalency plays a major role in biological processes and particularly in the relationship between pathogenic microorganisms and their host that involves protein-glycan recognition. these interactions occur during the first steps of infection, for specific recognition between host and bacteria, but also at different stages of the immune response. the search for high-affinity ligands for studying such interactions involves the combination of carbohydrate head groups with different scaffolds and ...201223254759
experimental and natural infections in myd88- and irak-4-deficient mice and humans.most toll-like-receptors (tlrs) and interleukin-1 receptors (il-1rs) signal via myeloid differentiation primary response 88 (myd88) and interleukin-1 receptor-associated kinase 4 (irak-4). the combined roles of these two receptor families in the course of experimental infections have been assessed in myd88- and irak-4-deficient mice for almost fifteen years. these animals have been shown to be susceptible to 46 pathogens: 27 bacteria, eight viruses, seven parasites, and four fungi. humans with i ...201223255009
chemical probing of glycans in cells and organisms.among the four major building blocks of life, glycans play essential roles in numerous physiological and pathological processes. due to their non-templated biosynthesis, advances towards elucidating the molecular details of glycan functions are relatively slow compared with the pace of protein and nucleic acid research. over the past 30 years, chemical tools have emerged as powerful allies to genetics and molecular biology in the study of glycans in their native environment. this tutorial review ...201223257905
chemical probing of glycans in cells and organisms.among the four major building blocks of life, glycans play essential roles in numerous physiological and pathological processes. due to their non-templated biosynthesis, advances towards elucidating the molecular details of glycan functions are relatively slow compared with the pace of protein and nucleic acid research. over the past 30 years, chemical tools have emerged as powerful allies to genetics and molecular biology in the study of glycans in their native environment. this tutorial review ...201223257905
"cross-glycosylation" of proteins in bacteroidales species.while it is now evident that the two bacteroidales species bacteroides fragilis and tannerella forsythia both have general o-glycosylation systems and share a common glycosylation sequon, the ability of these organisms to glycosylate a protein native to the other organism has not yet been demonstrated. here, we report on the glycosylation of heterologous proteins between these two organisms. using genetic tools previously developed for bacteroides species, two b. fragilis model glycoproteins wer ...201223258847
"cross-glycosylation" of proteins in bacteroidales species.while it is now evident that the two bacteroidales species bacteroides fragilis and tannerella forsythia both have general o-glycosylation systems and share a common glycosylation sequon, the ability of these organisms to glycosylate a protein native to the other organism has not yet been demonstrated. here, we report on the glycosylation of heterologous proteins between these two organisms. using genetic tools previously developed for bacteroides species, two b. fragilis model glycoproteins wer ...201223258847
microevolutionary analysis of clostridium difficile genomes to investigate transmission.the control of clostridium difficile infection is a major international healthcare priority, hindered by a limited understanding of transmission epidemiology for these bacteria. however, transmission studies of bacterial pathogens are rapidly being transformed by the advent of next generation sequencing.201223259504
insights into the crispr/cas system of gardnerella vaginalis.gardnerella vaginalis is identified as the predominant colonist of the vaginal tracts of women diagnosed with bacterial vaginosis (bv). g. vaginalis can be isolated from healthy women, and an asymptomatic bv state is also recognised. the association of g. vaginalis with different clinical phenotypes could be explained by different cytotoxicity of the strains, presumably based on disparate gene content. the contribution of horizontal gene transfer to shaping the genomes of g. vaginalis is acknowl ...201223259527
rna-seq based identification and mutant validation of gene targets related to ethanol resistance in cyanobacterial synechocystis sp. pcc 6803. 201223259593
application of protein purification methods for the enrichment of a cytotoxin from campylobacter jejuni.campylobater jejuni, a major foodborne diarrhoeal pathogen is reported to produce a number of cytotoxins of which only a cytolethal distending toxin (cdt) has been characterised so far. one or more additional cytotoxins other than cdt, including a chinese hamster ovary (cho) cell active, vero cell inactive cytotoxin, may mediate inflammatory diarrhoea. our objective was to develop a method to enrich and thus partially characterise this cytotoxin, as a pathway to the eventual identification and c ...201223259594
cubic time algorithms of amalgamating gene trees and building evolutionary scenarios.a long recognized problem is the inference of the supertree s that amalgamates a given set {g(j)} of trees g(j), with leaves in each g(j) being assigned homologous elements. we ground on an approach to find the tree s by minimizing the total cost of mappings α(j) of individual gene trees g(j) into s. traditionally, this cost is defined basically as a sum of duplications and gaps in each α(j). the classical problem is to minimize the total cost, where s runs over the set of all trees that contain ...201223259766
zoonotic fecal pathogens and antimicrobial resistance in county fair animals.livestock fairs present a unique opportunity for the public to experience close contact with animals, but may also expose people to zoonotic pathogens through contact with animal feces. the goal of this study was to screen cattle, sheep, goat, chicken, rabbit and horse feces from a livestock fair in california for the potentially zoonotic pathogens escherichia coli o157:h7, salmonella, campylobacter, vibrio, cryptosporidium and giardia spp., as well as determining the level of antimicrobial resi ...201323260373
prevalence and risk factors for shedding of thermophilic campylobacter in calves with and without diarrhea in austrian dairy herds.the objectives of this study were to evaluate the presence of thermophilic campylobacter in feces of calves with and without diarrhea on dairy farms and to survey farm characteristics and management practices to define risk factors for the presence of campylobacter. fifty dairy farms were chosen based on the presence of calf diarrhea, and 50 farms in which calves were free from diarrhea served as a standard of comparison. in total, fecal samples were taken from 382 calves. farm data and manageme ...201323261381
the design of a capsule polysaccharide conjugate vaccine against campylobacter jejuni serotype hs15.campylobacter jejuni infection is now the main cause of diarrhea-related illnesses in humans. an efficacious vaccine for the traveler and developing world market would be welcomed. we are engaged in the discovery and characterization of serotype-specific c. jejuni capsule polysaccharides (cpss) to study their role in virulence and as protective vaccine antigens. our prototype conjugate vaccine with serotype hs23 cps (strain 81-176) has been shown to fully protect non-human primates against diarr ...201323261782
growth inhibition of pathogenic bacteria by sulfonylurea herbicides.emerging resistance to current antibiotics raises the need for new microbial drug targets. we show that targeting branched-chain amino acid (bcaa) biosynthesis using sulfonylurea herbicides, which inhibit the bcaa biosynthetic enzyme acetohydroxyacid synthase (ahas), can exert bacteriostatic effects on several pathogenic bacteria, including burkholderia pseudomallei, pseudomonas aeruginosa, and acinetobacter baumannii. our results suggest that targeting biosynthetic enzymes like ahas, which are ...201223263008
the gtpase activity of flhf is dispensable for flagellar localization, but not motility, in pseudomonas aeruginosa.the opportunistic human pathogen pseudomonas aeruginosa uses two surface organelles, flagella and pili, for motility and adhesion in biotic and abiotic environments. polar flagellar placement and number are influenced by flhf, which is a signal recognition particle (srp)-type gtpase. the flhf proteins of bacillus subtilis and campylobacter jejuni were recently shown to have gtpase activity. however, the phenotypes associated with flhf deletion and/or mutation differ between these organisms and p ...201223264582
population structure in nontypeable haemophilus influenzae.nontypeable haemophilus influenzae (nthi) frequently colonize the human pharynx asymptomatically, and are an important cause of otitis media in children. past studies have identified typeable h. influenzae as being clonal, but the population structure of nthi has not been extensively characterized. the research presented here investigated the diversity and population structure in a well-characterized collection of nthi isolated from the middle ears of children with otitis media or the pharynges ...201223266487
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