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mutations in the gyra subunit of dna gyrase and the parc subunit of topoisomerase iv in clinical strains of fluoroquinolone-resistant shigella in anhui, china.in this research 26 shigella isolates were examined by pcr and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (qrdrs). we tested for the presence of qnr genes by pcr in 91 strains, but no qnr genes were found. the results did show, however, some novel mutations at codon 83 of gyra (ser-->ile) and codon 64 of parc (ala64-->cys, ala64-->asp), which were related to fluroquinolone resistance.200717483803
[identification and characterization of diarrheal microorganisms].acute diarrhea belongs to group of diseases caused by pathogenic microorganisms - salmonella, shigella and pathogenic strains of e.coli. despite the prophylactic measurements morbidity rate of diarrheal diseases remains very high especially in children and in traveling persons. among the main causes of illness is emerging of new strains of microorganisms, new serological versions of already known pathogens or antibiotic resistant strains of these pathogens. struggle against the resistant forms o ...200717595460
[study of antibiotic sensitivity of diarrheal microorganisms].as it was shown previously, detailed bacteriological analyses of 159 strains, among them museum and newly isolated strains of diarrheal patients from various clinics and bacteriology laboratories of tbilisi was carried out. study of antibiotic susceptibility of 52 strains of salmonella groups a, b, c, d, e and 42 shigella strains, among them 30 shigella flexneri and 12 shigella sonnei strains to 20 antibiotics and 1 chemical preparation was performed. 63% of salmonella strains were susceptible t ...200717595461
use of the tna operon as a new molecular target for escherichia coli detection.a quantitative real-time pcr targeting the tnaa gene was studied to detect escherichia coli and distinguish e. coli from shigella spp. these microorganisms revealed high similarity in the molecular organization of the tna operon.200717693560
differential regulation of caspase-1 activation, pyroptosis, and autophagy via ipaf and asc in shigella-infected macrophages.shigella infection, the cause of bacillary dysentery, induces caspase-1 activation and cell death in macrophages, but the precise mechanisms of this activation remain poorly understood. we demonstrate here that caspase-1 activation and il-1beta processing induced by shigella are mediated through ipaf, a cytosolic pattern-recognition receptor of the nucleotide-binding oligomerization domain (nod)-like receptor (nlr) family, and the adaptor protein apoptosis-associated speck-like protein containin ...200717696608
identification of minor inner-membrane components of the shigella type iii secretion system 'needle complex'.type iii secretion systems (t3sss or secretons) are central virulence factors of many gram-negative bacteria, used to inject protein effectors of virulence into eukaryotic host cells. their overall morphology, consisting of a cytoplasmic region, an inner- and outer-membrane section and an extracellular needle, is conserved in various species. a portion of the secreton, containing the transmembrane regions and needle, has been isolated biochemically and termed the 'needle complex' (nc). however, ...200717660405
the acid-resistance pathways of shigella flexneri 2457t.the stationary-phase acid-resistance pathways of shigella flexneri 2457t have not previously been studied. the two acid-resistance systems, the glutamate-dependent acid-resistance (gdar) and the oxidative pathways, reported elsewhere for escherichia coli and s. flexneri 3136, were both detected in s. flexneri 2457t. however, s. flexneri 2457t cells grown overnight under fermentative conditions and acid-shocked in minimal media in the absence of glutamate, an acid test often described as a negati ...200717660423
brucella abortus requires the heme transporter bhua for maintenance of chronic infection in balb/c mice.the gene annotated bab2_1150 in the brucella abortus 2308 genome sequence is predicted to encode a homolog of the well-characterized heme transporter shua of shigella dysenteriae and accordingly has been given the designation bhua (brucella heme utilization). phenotypic analysis of an isogenic bhua mutant derived from b. abortus 2308 verified that there is a link between bhua and the ability of the parent strain to use heme as an iron source in in vitro assays. maximum expression of bhua in b. a ...200717709407
shigella flexneri phagosomal escape is independent of invasion.infections with salmonella enterica serovar typhimurium and shigella flexneri result in mucosal inflammation in response to epithelial cell invasion and macrophage cytotoxicity. these processes are mediated by type iii secretion systems encoded in homologous virulence loci in the two species, namely, salmonella pathogenicity island 1 (spi-1), carried in the genome, and the shigella entry region (ser), carried in a large virulence plasmid. here we show that spi-1 can functionally complement a del ...200717664266
icsa surface presentation in shigella flexneri requires the periplasmic chaperones degp, skp, and sura.a shigella flexneri degp mutant, which was defective for plaque formation in henle cell monolayers, had a reduced amount of icsa detectable on the bacterial surface with antibody. however, the mutant secreted icsa to the outer membrane at wild-type levels. this suggests that icsa adopts an altered conformation in the outer membrane of the degp mutant with reduced exposure on the cell surface. icsa is, therefore, unlikely to be accessible to actin-nucleating proteins within the eukaryotic cell cy ...200717526712
site-specific modification of shigella flexneri virf mrna by trna-guanine transglycosylase in vitro.shigella flexneri is an enteropathogen responsible for severe dysentery in humans. virf is a key transcriptional regulator that activates the expression of the downstream virulence factors required for cellular invasion and cell-to-cell spread of this pathogen. there are several environmental factors that induce the translation of virf including temperature, ph, osmolarity and post-transcriptional rna modification. durand and colleagues (vacc, a virulence-associated chromosomal locus of shigella ...200717626052
prevalence of bacterial pathogens in biofilms of drinking water distribution systems.water for human consumption is required to be free from any bacteria that might pose a health risk. the presence of biofilms in the drinking water distribution system may play a role in the presence of potential pathogens in the drinking water supply. ninety-five biofilm samples from various parts of south africa were tested for the presence of escherichia coli, aeromonas, pseudomonas, salmonella, shigella and vibrio spp. members of these genera were quantified by the three-tube most probable nu ...200717674571
genes under positive selection in escherichia coli.we used a comparative genomics approach to identify genes that are under positive selection in six strains of escherichia coli and shigella flexneri, including five strains that are human pathogens. we find that positive selection targets a wide range of different functions in the e. coli genome, including cell surface proteins such as beta barrel porins, presumably because of the involvement of these genes in evolutionary arms races with other bacteria, phages, and/or the host immune system. st ...200717675366
recent gene conversions between duplicated glutamate decarboxylase genes (gada and gadb) in pathogenic escherichia coli.escherichia coli have evolved adaptive systems to resist strongly acidic habitats in part through the production of 2 biochemically identical isoforms of glutamate decarboxylase (gad), encoded by the gada and gadb genes. these genes occur in e. coli and other members of the genospecies (e.g., shigella spp.) and originated as part of a genomic fitness island acquired early in escherichia evolution. the present duplicated gad loci are widely spaced on the e. coli chromosome, and the 2 genes are 97 ...200717675652
role of u.s. military research programs in the development of u.s.-licensed vaccines for naturally occurring infectious diseases.u.s. military physicians and researchers have collaborated in the development of eight u.s.-licensed vaccines since 1934, when product efficacy requirements were added to product safety requirements mandated in 1902. these vaccines include influenza (1945), rubella (1969), adenovirus types 4 and 7 (1980), meningococcus a, c, y, w-135 (1981), hepatitis b (1981), oral typhoid (1989), japanese encephalitis (1992), and hepatitis a (1995). current efforts include new adenovirus and japanese encephali ...200717728025
the two-faced role of cad genes in the virulence of pathogenic escherichia coli.in enterobacteria, acid stress induces expression of the cad system which is involved in maintaining intracellular ph at levels compatible with cell survival. despite its crucial role, the cad operon is silenced in shigella and in other pathogenic escherichia coli. in the present review, we will address the question of why and how the cad locus has been sacrificed for the sake of optimal expression of virulence traits.200717656072
preparation and characterization of translocator/chaperone complexes and their component proteins from shigella flexneri.shigella flexneri causes a severe form of bacillary dysentery also known as shigellosis. onset of shigellosis requires bacterial invasion of colonic epithelial cells which is initiated by the delivery of translocator and effector proteins to the host cell membrane and cytoplasm, respectively, by the shigella type iii secretion system (ttss). the shigella translocator proteins, ipab and ipac, form a pore complex in the host cell membrane to facilitate effector delivery; however, prior to their se ...200717571858
explaining unexplained diarrhea and associating risks and infections.gastrointestinal illnesses are common afflictions. however, knowledge of their etiology is often lacking. moreover, most cases of infections with reportable enteric pathogens (campylobacter jejuni, escherichia coli o157:h7, salmonella, shigella, yersinia, cryptosporidia and giardia) have sporadic modes of acquisition, yet control measures are often biased towards mitigation of risks discerned by outbreak analysis. to determine the etiology of unexplained diarrhea it is important to study populat ...200717692144
synthesis and structure-activity relationship of 7-(substituted)-aminomethyl-4-quinolone-3-carboxylic acid derivatives.gram-positive organisms have re-emerged as the major hospital pathogens, which make the unmet medical needs for antibacterial therapy even worse. in searching for potent agents against gram-positive pathogens, novel 7-(substituted)-aminomethyl-quinolone-3-carboxylic acids were designed, synthesized, and evaluated for their antibacterial activities in vitro. many 7-monoarylaminomethyl derivatives exhibited high potency against gram-positive organisms compared to reference agents: vancomycin and p ...200717826097
antimicrobial and antioxidant properties of rosemary and sage (rosmarinus officinalis l. and salvia officinalis l., lamiaceae) essential oils.the essential oils of rosemary ( rosmarinus officinalis l.) and sage ( salvia officinalis l.) were analyzed by means of gas chromatography-mass spectrometry and assayed for their antimicrobial and antioxidant activities. antimicrobial activity was tested against 13 bacterial strains and 6 fungi, including candida albicans and 5 dermatomycetes. the most important antibacterial activity of both essential oils was expressed on escherichia coli, salmonella typhi, s. enteritidis, and shigella sonei. ...200717708648
spontaneous zygogenesis, a wide-ranging mating process in bacteria.spontaneous zygogenesis (or z-mating) in escherichia coli, unlike f-mediated conjugation, promotes formation of complete zygotes. most z-mating products have proven to be phenotypically unstable, losing part of the phenotype for which they were selected. persistent z-mating products appear as stable genetic recombinants or yield subclones of two types: either both parental types or one of them plus a recombinant type, and the ability to promote spontaneous zygogenesis can appear in all emerging ...200717720456
bacterial, fungal and parasitic contamination of cockroaches in public hospitals of hamadan, iran.to determine the possible role of cockroaches in dissemination of medically important microorganisms, a study was carried out in public hospitals and residential areas of hamadan city, west of iran. bacteria, fungi and parasites of medical importance were isolated and identified. the total number of blattella germanica collected from hospitals were 133 as the case group. the cockroaches collected from residential areas were 45 as the control group.200717722863
[analysis on the status of shigella spp antimicrobial resistance through data from the national shigellosis surveillance system in china, in 2005].the ministry of public health released the national surveillance project on shigellosis in august, 2005. this study was to reveal the antimicrobial resistance status of shigella isolates through the national shigellosis surveillance system in 2005 in china, so as to provide evidence for the development of surveillance, prevention and cure of shigellosis.200717850709
the significance of the number of submitted samples and patient-related factors for faecal bacterial diagnostics.the sensitivity of bacteriological testing of faecal samples from patients with diarrhoea has not been properly determined. the present study analysed the association between the results of stool sample examinations and the number of samples examined per patient and other patient-related factors. data concerning faecal specimens referred for culture for enteric bacterial pathogens (campylobacter, salmonella, shigella and yersinia) to the central microbiological laboratory in denmark between 1995 ...200717727686
prevalence of campylobacter jejuni and enteric bacterial pathogens among hospitalized hiv infected versus non-hiv infected patients with diarrhoea in southern india.a prevalence study on campylobacter jejuni and other enteric bacterial pathogens was carried out in 200 hiv infected and 200 non-hiv infected subjects with diarrhoeal symptoms at an aids hospital in southern india. diarrhoeal specimens were inoculated onto standard culture media as well as onto columbia and campylobacter blood agar media for c. jejuni isolation. all the c. jejuni isolates were tested for antimicrobial susceptibility using kirby-bauer's method. a significant difference in recover ...200717852888
diarrhoeagenic escherichia coli and other causes of childhood diarrhoea: a case-control study in children living in a wastewater-use area in hanoi, vietnam.a case-control study was conducted to identify the aetiology of diarrhoeal diseases in pre-school children in a suburban area of hanoi where the use of untreated wastewater in agriculture and aquaculture is a common practice. stool specimens and clinical information were collected from 111 pairs of children with diarrhoea and healthy controls. a total of 73 cases (66 %) and 41 controls (36 %) had an enteric pathogen. the pathogens most often associated with diarrhoea were rotavirus (17 % of case ...200717644717
cross-species cluster co-conservation: a new method for generating protein interaction networks.co-conservation (phylogenetic profiles) is a well-established method for predicting functional relationships between proteins. several publicly available databases use this method and additional clustering strategies to develop networks of protein interactions (cluster co-conservation (ccc)). ccc has previously been limited to interactions within a single target species. we have extended ccc to develop protein interaction networks based on co-conservation between protein pairs across multiple sp ...200717803817
serum sperm antibodies after diarrhoeal diseases.the origin of 'natural' anti-sperm antibodies found in fertile humans, virgin girls, and boys before puberty, is quite obscure. one hypothetical mechanism relates their existence to inflammatory gastrointestinal entities: as a result of the disease, cross-reactive antibodies produced against gastrointestinal flora bind spermatozoa. to test this assumption, we evaluated the level of serum sperm antibodies after diarrhoeal infections. serum samples from 17 patients with shigellosis and 12 patients ...200717683470
multilocus variable-number tandem-repeat analysis for molecular typing of shigella sonnei.a multilocus variable-number tandem-repeat (vntr) analysis (mlva) method was developed and evaluated for the subtyping of shigella sonnei isolates. a total of 26 vntr loci were identified by exploring the repeat sequence loci in the genomic sequences of s. sonnei strains ss046 and 53g and by testing 536 isolates that had previously been characterized by pulsed-field gel electrophoresis (pfge). the discriminatory power of mlva (simpson's index of diversity [d], 0.9524; 95% confidence interval [ci ...200717881552
plasmid-mediated quinolone resistance conferred by qnrs1 in salmonella enterica serovar virchow isolated from turkish food of avian origin.to study the molecular characteristics of the quinolone and associated ampicillin resistance mechanisms present in salmonella enterica serovar virchow isolated from turkish foods.200717881633
intracellular type iii secretion by cytoplasmic shigella flexneri promotes caspase-1-dependent macrophage cell death.the gram-negative bacterium shigella flexneri triggers pro-inflammatory apoptotic cell death in macrophages, which is crucial for the onset of an acute inflammatory diarrhoea termed bacillary dysentery. the mxi-spa type iii secretion system promotes bacterial uptake and escape into the cytoplasm, where, dependent on the translocator/effector protein ipab, caspase-1 [interleukin (il)-1beta-converting enzyme] and its substrate il-1beta are activated. here, we show that in the course of a macrophag ...200717768231
escherichia coli, shigella and salmonella species in acute diarrhoea in hamedan, islamic republic of iran.this study investigated the frequency of escherichia col, shigella and salmonella species in stool specimens from patients with diarrhoea presenting to health centres in hamedan province, islamic republic of iran. from 144 samples, shigella strains were isolated in 17 cases (11.8%): 10 sh. flexneri, 3 sh. sonnei, 2 sh. boydii and 2 untyped strains. no salmonella strains were isolated. using molecular diagnostic methods, diarrheogenic e. coli were detected in 37 cases (25.7%), the majority were e ...200717684844
in vitro antimicrobial activity of rifaximin against enteropathogens causing traveler's diarrhea.the in vitro activity of rifaximin against 84 diarrheagenic escherichia coli and 11 shigella sonnei causing traveler's diarrhea was evaluated. the mic of rifaximin ranged between <0.007 and 32 mg/l; other agents tested had an mic of >256 mg/l in most cases. the results showed the potential use of rifaximin to treat these infections.200717889485
comparative sequence analysis of acid sensitive/resistance proteins in escherichia coli and shigella flexneri.the molecular basis for the survival of bacteria under extreme conditions in which growth is inhibited is a question of great current interest. a preliminary study was carried out to determine residue pattern conservation among the antiporters of enteric bacteria, responsible for extreme acid sensitivity especially in escherichia coli and shigella flexneri. here we found the molecular evidence that proved the relationship between e. coli and s. flexneri. multiple sequence alignment of the gadc c ...200721670792
antibacterial, antifungal and cytotoxic activities of amblyone isolated from amorphophallus campanulatus.to assess the in vitro antibacterial, antifungal and cytotoxic activities of amblyone, a triterpenoid isolated from amorphophallus campanulatus (roxb).200821264161
part ii. analysis of data gaps pertaining to shigella infections in low and medium human development index countries, 1984-2005.the global incidence of shigella infection has been estimated at 80-165 million episodes annually, with 99% of episodes occurring in the developing world. to identify contemporary gaps in the understanding of the global epidemiology of shigellosis, we conducted a review of the english-language scientific literature from 1984 to 2005, restricting the search to low and medium human development countries. our review yielded 11 population-based studies of shigella burden from seven countries. no pop ...200817686195
drastic decrease of salmonella enteritidis isolated from humans in belgium in 2005, shift in phage types and influence on foodborne outbreaks.in belgium, non-typhoidal salmonellosis and campylobacteriosis are the two most frequently reported foodborne illnesses. during 2005, a 71% decrease of salmonella enteritidis infections compared with the average annual number cases in the period 2000-2004 was recorded by the belgian national reference centre for salmonella and shigella. after the peak of 1999, the total number of salmonellosis cases decreased gradually, with the exception of 2003 when an increase was again recorded due to the ri ...200817645812
risk areas and neighborhood-level risk factors for shigella dysenteriae 1 and shigella flexneri.annually, there are 165 million cases of shigellosis resulting in 1.1 million deaths in the developing world. two species of the causative agent, shigella dysenteriae 1 and shigella flexneri, are responsible for acute diarrheal illness. vaccines are being developed against both but many questions remain about the disease burden, distribution of species in space and time, and community-level risk factors. this study answers two questions. what are the differences in neighborhood-level risk factor ...200817602851
isolation and antibiotic susceptibility of salmonella and shigella strains isolated from children in gaza, palestine from 1999 to 2006.diarrhea and acute gastroenteritis are among the leading causes of illnesses and death in infants and children throughout the world, especially in developing countries, globally, salmonella and shigella remain the major contributors to acute enteric infections and diarrhea.200817854424
synthesis, characterization and antibacterial activity of cobalt(iii) complexes with pyridine-amide ligands.the ligands 2-(n-(x-pyridyl)carbamoyl)pyridine (x=2, 3 or 4 for hl1-hl3, respectively) and 2,6-bis(n-(y-pyridyl)carbamoyl)pyridine (y=2, 3 or 4 for h2l4-h2l6, respectively) in their mono- and di-deprotonated forms have been used to synthesize kinetically stable cobalt(iii) compounds [co(l1-3)3] (1-3) and na[co(l4-6)2] (4-6), respectively. the co(iii) ion is in octahedral environment and is surrounded by three bidentate ligands in complexes 1-3 and two tridentate ligands in complexes 4-6. ligands ...200817959275
development of a tripartite vector system for live oral immunization using a gram-negative probiotic carrier.the mucosa represents the primary target site and thus the first barrier for most microbial pathogens. nevertheless, nearly all present-day vaccines are applied by an invasive route, target the systemic immune system, and do not confer efficient mucosal protection. currently, mucosal immunity can only be achieved by the delivery of antigens via the mucosal route. therefore, multiple efforts are under way to develop mucosal vaccines and particularly live oral vaccines as these would confer consid ...200817936683
identification of newly recognized serotype 1c as the most prevalent shigella flexneri serotype in northern rural vietnam.we investigated the identity of 37 shigella flexneri strains that had previously been isolated from northern rural vietnam (son tay province) and described as untypable. twenty-four isolates reacted with masf 1c, a monoclonal antibody specific for s. flexneri serotype 1c. a further ten untypable isolates were found to be rough mutants (no longer expressing o-antigen) that were derived from serotype 1c strains. pulsed-field gel electrophoresis demonstrated that these strains consisted of many dif ...200817922932
a role for nod-like receptors in autophagy induced by shigella infection.shigella infection, the cause of bacillary dysentery, induces caspase-1 activation and cell death in macrophages, but the precise mechanisms remain poorly understood. in our recent study, we presented evidence that caspase-1 activation and il-1beta processing induced by shigella are mediated through ipaf, a cytosolic pattern-recognition receptor of the nucleotide-binding oligomerization domain (nod)-like receptor (nlr) family and the adaptor protein apoptosis-associated speck-like protein contai ...200817932464
detection of the causative agent of furunculusis, aeromonas salmonicida in salmonids of the krka river.in this paper we describe the bacterial community associated with salmonids from the krka river. diversity analysis demonstrated that majority of the recovered bacteria were related to aeromonadaceae group. bacterial analysis also revealed the presence of shigella spp. and pseudomonas fluorescens. isolation of aeromonas salmonicida from trout, presents first isolation of this bacteria croatian rivers.200817624808
the use of clinical profiles in the investigation of foodborne outbreaks in restaurants: united states, 1982-1997.improving the efficiency of outbreak investigation in restaurants is critical to reducing outbreak-associated illness and improving prevention strategies. because clinical characteristics of outbreaks are usually available before results of laboratory testing, we examined their use for determining contributing factors in outbreaks caused by restaurants. all confirmed foodborne outbreaks reported to the centers for disease control and prevention (cdc) from 1982 to 1997 were reviewed. clinical pro ...200817335632
bacterial reduction of selenate to elemental selenium utilizing molasses as a carbon source.selecting an inexpensive and effective organic carbon source is the key to reducing the cost in selenium (se) remediation. five bacteria were screened based on their ability in using molasses as an organic carbon source to reduce selenate [se(vi)] in drainage water. efficiency of se removal differed in the molasses-added drainage water containing different bacteria, with an order of enterobacter taylorae>pantoea sp. sss2>klebsiella sp. wrs2>citerobacter freundii>shigella sp. dw2. by using e. tay ...200817512724
emerging resistance to newer antimicrobial agents among shigella isolated from finnish foreign travellers.in finland, most cases of shigellosis are related to travel abroad. antimicrobial drug resistance of 1814 shigella strains isolated from finnish patients during 1990-2005 was studied using discs of 12 antimicrobial agents. since 2000, the e-test has been performed to determine ciprofloxacin minimum inhibitory concentrations of nalidixic acid-resistant isolates. the proportion of multi-resistant strains (resistant to >or =4 antimicrobials) was highest among isolates from china and india, but is i ...200817578602
evaluating burkholderia pseudomallei bip proteins as vaccines and bip antibodies as detection agents.burkholderia pseudomallei is a biothreat agent and an important natural pathogen, causing melioidosis in humans and animals. a type iii secretion system (ttss-3) has been shown to be critical for virulence. because ttss components from other pathogens have been used successfully as diagnostic agents and as experimental vaccines, it was investigated whether this was the case for bipb, bipc and bipd, components of b. pseudomallei's ttss-3. the sequences of bipb, bipc and bipd were found to be high ...200817995960
priming of cd4+ t cells with porin of shigella dysenteriae activates the cells toward type 1 polarization.macrophages treated with porin of shigella dysenteriae were potent stimulators of naive t(h) cells since the porin-pulsed macrophages strongly proliferated the t cells and up-regulated the activation molecules cd69 and cd25 on cd4(+) t cells in allogeneic mixed leukocyte reaction. immunization of c57bl/6 mice with porin selectively induced the intracellular expression and release of ifn-gamma and had no effect on il-4 expression. in parallel to the predominant release of the t(h)1 cytokine ifn-g ...200818003602
the nlee/ospz family of effector proteins is required for polymorphonuclear transepithelial migration, a characteristic shared by enteropathogenic escherichia coli and shigella flexneri infections.enteropathogenic escherichia coli (epec) and shigella flexneri are human host-specific pathogens that infect intestinal epithelial cells. however, each bacterial species employs a different infection strategy within this environmental niche. epec attaches to the apical surface of small intestine enterocytes, causing microvillus effacement and rearrangement of the host cell cytoskeleton beneath adherent bacteria. in contrast, s. flexneri invades the large intestine epithelium at the basolateral m ...200817984206
the pattern-recognition molecule nod1 is localized at the plasma membrane at sites of bacterial interaction.the pattern-recognition molecule nod1 is a critical sensor for bacterial derived diaminopimelic acid-containing peptidoglycan fragments which induces innate immune responses in epithelial cells. here we report the subcellular localization of this protein in human epithelial cells. nod1 is localized in the cytosol and at the plasma membrane in human cells. this membrane association is dependent on the integrity of the protein, on its signalling capacity and on an intact actin cytoskeleton. signal ...200817970764
clostridium difficile: an under-recognized cause of reactive arthritis?reactive arthritis usually presents as a sterile, inflammatory, asymmetric oligoarthritis, affecting large lower extremity joints. extra-articular features (conjunctivitis, uveitis, enthesopathy, urethritis, balanitis, keratoderma blenorrhagicum) may occur. common causes of enteric reactive arthritis are preceding infections attributable to salmonella, shigella, campylobacter, and yersinia. in contrast, clostridium difficile is an uncommon cause of reactive arthritis, with only approximately 40 ...200817902012
bacterial and fungal infections among diagnostic laboratory workers: evaluating the risks.accidental infections acquired in the laboratory environment are not reportable in a formal forum outside the institution, and therefore, there is little opportunity to evaluate such occurrences and learn from them. we evaluated voluntary responses from 88 facilities, 53 large hospitals (>200 beds) or academic institutions, 32 smaller facilities (<200 beds), and 3 national reference diagnostic laboratories. thirty-eight of the laboratories (43%), 15 large and 23 small facilities, reported no kno ...200817997259
enteropathogen resource integration center (eric): bioinformatics support for research on biodefense-relevant enterobacteria.eric, the enteropathogen resource integration center (www.ericbrc.org), is a new web portal serving as a rich source of information about enterobacteria on the niaid established list of select agents related to biodefense-diarrheagenic escherichia coli, shigella spp., salmonella spp., yersinia enterocolitica and yersinia pestis. more than 30 genomes have been completely sequenced, many more exist in draft form and additional projects are underway. these organisms are increasingly the focus of st ...200817999997
role of shigella infection in endometriosis: a novel hypothesis.endometriosis is the presence of endometrial cells and stroma at ectopic sites outside the uterine cavity. the natural history of endometriosis is uncertain, its etiology unknown, the clinical presentation inconsistent, diagnosis difficult and the treatment poorly standardized. it causes significant morbidity due to pelvic pain and infertility among 15-25% of women during their reproductive age. the benign disease causes peritoneal inflammation, fibrosis, adhesions and ovarian cysts but displays ...200817888583
contribution of the sitabcd, mnth, and feob metal transporters to the virulence of avian pathogenic escherichia coli o78 strain chi7122.the roles of sitabcd, mnth, and feob metal transporters in the virulence of avian pathogenic escherichia coli (apec) o78 strain chi7122 were assessed using isogenic mutants in chicken infection models. in a single-strain infection model, compared to chi7122, the deltasit strain demonstrated reduced colonization of the lungs, liver, and spleen. complementation of the deltasit strain restored virulence. in a coinfection model, compared to the virulent apec strain, the deltasit strain demonstrated ...200818025097
isolation and purification of enterocin e-760 with broad antimicrobial activity against gram-positive and gram-negative bacteria.strain nrrl b-30745, isolated from chicken ceca and identified as enterococcus durans, enterococcus faecium, or enterococcus hirae, was initially identified as antagonistic to campylobacter jejuni. the isolate produced a 5,362-da bacteriocin (enterocin) that inhibits the growth of salmonella enterica serovar enteritidis, s. enterica serovar choleraesuis, s. enterica serovar typhimurium, s. enterica serovar gallinarum, escherichia coli o157:h7, yersinia enterocolitica, citrobacter freundii, klebs ...200818086839
shiga toxin 1 induces apoptosis through the endoplasmic reticulum stress response in human monocytic cells.shiga toxins (stxs) expressed by the enteric pathogens shigella dysenteriae 1 and enterohaemorrhagic escherichia coli are potent protein synthesis inhibitors. shiga toxins have also been shown to induce apoptosis in epithelial, endothelial and monocytic cells. the precise relationship between protein synthesis inhibition and induction of apoptosis is not known. we show that stimulation of the myelogenous leukaemia cell line thp-1 with purified stx1 induced the endoplasmic reticulum (er) stress r ...200818005243
saccharomyces boulardii interferes with shigella pathogenesis by postinvasion signaling events.saccharomyces boulardii is gaining in popularity as a treatment for a variety of diarrheal diseases as well as inflammatory bowel disease. this study was designed to examine the effect of this yeast on infection by shigella flexneri, a highly infectious and human host-adapted enteric pathogen. we investigated key interactions between the bacteria and host cells in the presence of the yeast in addition to a number of host responses including proinflammatory events and markers. although the presen ...200818032477
[hemolytic and uremic syndrome in the child].hemolytic and uremic syndrome (hus) is characterized by the association of hemolytic anemia with sckizocytes, thrombopenia and renal involvement secondary to thrombotic microangiopathy. the typical form is the most frequent in children occurring after an episode of diarrhea caused by escherichia coli. other microorganisms may be responsible for hus such as shigella dysenteriae or streptococcus pneumoniae. acute renal failure is reversible in most cases, but long-term renal sequelae are seen in o ...200817964233
the versatility of shigella effectors.when shigella infect the intestinal epithelium, they deliver several effectors through the type iii secretion system (t3ss) into the surrounding space and directly into the host-cell cytoplasm, where they can mimic and usurp host cellular functions or subvert host-cell signalling pathways and the immune response. although bacterial strategies and mechanisms of infection vary greatly, recent studies of shigella effectors have revealed that shigella possess a highly evolved strategy for infection.200818059288
bacterial actin assembly requires toca-1 to relieve n-wasp autoinhibition.actin polymerization in the mammalian cytosol can be locally activated by mechanisms that relieve the autoinhibited state of n-wasp, an initiator of actin assembly, a process that also requires the protein toca-1. several pathogenic bacteria, including shigella, exploit this host feature to infect and disseminate efficiently. the shigella outer membrane protein icsa recruits n-wasp, which upon activation at the bacterial surface mediates localized actin polymerization. the molecular role of toca ...200818191793
conserved amphiphilic feature is essential for periplasmic chaperone hdea to support acid resistance in enteric bacteria.the extremely acidic environment of the mammalian stomach (ph 1-3) represents a stressful challenge for enteric pathogenic bacteria, including escherichia coli, shigella and brucella. the hdea (hns-dependent expression a) gene was found to be crucial for the survival of these enteric bacteria under extremely low ph conditions. we recently demonstrated that hdea is able to exhibit chaperone-like activity exclusively within the stomach ph range by transforming from a well-folded conformation at hi ...200818271752
reactive arthritis following culture-confirmed infections with bacterial enteric pathogens in minnesota and oregon: a population-based study.to describe the epidemiology and clinical spectrum of reactive arthritis (rea) following culture-confirmed infection with bacterial enteric pathogens in a population-based study in the usa.200818272671
systemic pharmacokinetics of rifaximin in volunteers with shigellosis.rifaximin is an oral antibiotic indicated for treatment of traveler's diarrhea. rifaximin pharmacokinetics were evaluated in individuals challenged with shigella flexneri. peak plasma rifaximin concentrations were low after nine consecutive doses, and no accumulation was observed. rifaximin serum levels were minimal and similar to those previously reported in studies of healthy volunteers.200818086855
distribution and antibiotic susceptibility of shigella isolates in bangui, central african republic.we conducted a prospective study in four urban health care centres between january 2004 and november 2005 to determine the distribution and susceptibility patterns of shigella strains causing invasive diarrhoea in bangui, central african republic. of the 155 shigella isolated, shigella flexneri (51%) and shigella dysenteriae (30%) were the most common and the most resistant to usual antibiotics, including amoxicillin, sulphamethoxazole-trimethoprim and chloramphenicol. though multi-drug resistan ...200818282240
extracellular-loop peptide antibodies reveal a predominant hemichannel organization of connexins in polarized intestinal cells.shigella, the causative agent of bacillary dysentery, invades colonic epithelial cells to elicit an intense inflammatory reaction leading to destruction of the mucosa. atp-dependent paracrine signalling induced by connexin (cx) hemichannel opening was previously shown to favor shigella flexneri invasion and dissemination in transfectants of hela cells [g. tran van nhieu, c. clair, r. bruzzone, m. mesnil, p. sansonetti and l. combettes. (2003). connexin-dependent intercellular communication incre ...200818267319
comparative analysis of intestinal microbial community diversity between healthy and orally infected ducklings with salmonella enteritidis by eric-pcr.to analyze the difference of intestinal microbial community diversity between healthy and (s. enteritidis) orally infected ducklings.200818286697
terpenoid compositions, and antioxidant and antimicrobial properties of the rhizome essential oils of different hedychium species.a phytochemical study of the rhizome essential oils of four different hedychium species was performed by means of gc and gc/ms analyses. h. ellipticum mainly contained 1,8-cineole, sabinene, and terpin-4-ol, while h. aurantiacum possessed terpin-4-ol, para-cymene, and bornyl acetate as the major entities. similarly, trans-meta-mentha-2,8-diene and linalool were noticed in h. coronarium. three different collections (i-iii) of h. spicatum showed amazing differences in the relative contents of thei ...200818293443
cytoplasmic targeting of ipac to the bacterial pole directs polar type iii secretion in shigella.type iii secretion (t3s) systems are largely used by pathogenic gram-negative bacteria to inject multiple effectors into eukaryotic cells. upon cell contact, these bacterial microinjection devices insert two t3s substrates into host cell membranes, forming a so-called 'translocon' that is required for targeting of type iii effectors in the cell cytosol. here, we show that secretion of the translocon component ipac of invasive shigella occurs at the level of one bacterial pole during cell invasio ...200818188151
the chaperone ipgc copurifies with the virulence regulator mxie.the expression of a subset of shigella flexneri virulence genes is dependent upon a cytoplasmic chaperone, ipgc, and an activator from the arac/xyls family, mxie. in this paper, we report that the chaperone forms a specific and stable heteromer with mxie.200818192384
single residue determines the specificity of neutrophil elastase for shigella virulence factors.human neutrophil elastase (ne) is a key host defense protease that cleaves virulence factors of gram-negative bacteria. ne and cathepsin g (cg) are chymotrypsin-like serine proteases with sequence and structural similarities, and both are abundant in neutrophil granules. unlike ne, cg does not cleave virulence factors of enteric bacteria. through structure-function analysis, we identified regions in ne that are essential for cleaving shigella virulence proteins. ne residues at eight different po ...200818295791
role and regulation of iron-sulfur cluster biosynthesis genes in shigella flexneri virulence.shigella flexneri, a causative agent of bacterial dysentery, possesses two predicted iron-sulfur cluster biosynthesis systems called suf and isc. s. flexneri strains containing deletion mutations in the entire suf operon (ur011) or the iscsua genes (ur022) were constructed. both mutants were defective in surviving exposure to oxidative stress. the suf mutant showed growth that was comparable to that of the parental strain in both iron-replete and iron-limiting media; however, the isc mutant show ...200818195027
evaluation of faecal occult blood test and lactoferrin latex agglutination test in screening hospitalized patients for diagnosing inflammatory and non-inflammatory diarrhoea in dhaka, bangladesh.inflammatory diarrhoea (id) resulting from shigella, salmonella, campylobacter and entamoeba histolytica requires specific diagnosis for therapy. differentiation between id and non-inflammatory diarrhoea (nid) is often not clinically possible. a faecal occult blood test (fobt) correlates with faecal leucocytes. lactoferrin indicates an inflammatory process as a marker for faecal leucocytes. we evaluated diagnostic values of lactoferrin latex agglutination test (lt) either alone or in combination ...200818196900
a five-year antimicrobial resistance pattern of shigella isolated from stools in the gondar university hospital, northwest ethiopia.shigellosis is a global health problem. however, developing countries, where there is poor hygiene and unsafe water supplies, are especially affected. in the last two decades shigella isolates have become increasingly resistant to many commonly used drugs. we investigated the antibiotic susceptibility pattern of shigella isolated from stool specimens processed over five years in the bacteriology laboratory of the university of gondar teaching hospital in northwest ethiopia. stool specimens were ...200818302868
new information about pediatric foodborne infections: the view from foodnet.diarrheal illness is a significant burden to children and their parents. recent studies describing the etiologic agents that cause diarrheal illness and examining the risk factors for the most common bacterial enteric pathogens are presented.200818197044
retrograde traffic in the biosynthetic-secretory route.in the biosynthetic-secretory route from the rough endoplasmic reticulum, across the pre-golgi intermediate compartments, the golgi apparatus stacks, trans golgi network, and post-golgi organelles, anterograde transport is accompanied and counterbalanced by retrograde traffic of both membranes and contents. in the physiologic dynamics of cells, retrograde flow is necessary for retrieval of molecules that escaped from their compartments of function, for keeping the compartments' balances, and mai ...200818270728
immunogenicity and efficacy of highly purified invasin complex vaccine from shigella flexneri 2a.development of a subunit vaccine for shigellosis requires identification of protective antigens and delivering these antigens in a manner that stimulates immunity comparable to that induced by natural infection. the shigella invasin complex (invaplex) vaccine is an ion-exchange-purified extract from virulent shigella that consists of lps and several other proteins, including the invasins ipab and ipac. intranasal delivery of invaplex stimulates protective immunity in small animal models for shig ...200818276045
[antigenic polysaccharides of bacteria: 40. the structures of o-specific polysaccharides from shigella dysenteriae types 3 and 9 and s. boydii type 4 revised by nmr spectroscopy].the reported structures of o-specific polysaccharides from three standard strains of shigella bacteria were corrected by modern nmr techniques. the revisions concerned the configuration of the o-glycoside linkage (s. dysenteriae type 3, structure 1), the positions of monosaccharide residue glycosylation and acetylation by pyruvic acid (s. dysenteriae type 9, structure 2), and the attachment position of the side monosaccharide chain (s. boydii type 4, structure 3) [struxture in text].200818365747
contamination of a blood culture with shigella sonnei. 200818371521
analysis of rho-gtpase mimicry by a family of bacterial type iii effector proteins.microbial pathogens may hijack the actin cytoskeleton machinery to facilitate actin-based motility, cellular invasion, and intracellular trafficking through the endocytic pathway. of particular interest has been a large class of virulence factors collectively termed the type iii "effector" proteins. following contact with a eukaryotic cell, gram-negative bacterial pathogens employ a dedicated protein secretion apparatus termed type iii to translocate effector proteins into the cellular cytoplasm ...200818374161
reaching a consensus on management practices and vaccine development targets for mitigation of infectious diarrhoea among deployed us military forces.this study is part of a research effort to identify and quantify factors related to the cost-effectiveness of a vaccine acquisition strategy to reduce the burden of infectious diarrhoea on us military personnel deployed overseas. where evidence is lacking in the scientific literature, or considerable uncertainty exists, it is often necessary to develop best estimates with ranges of certainty. to this end, a modified 'delphi' survey technique to obtain the best estimates for uncertain parameters ...200818284518
socioeconomic risk factors for bacterial gastrointestinal infections.bacterial gastrointestinal infections cause considerable morbidity in industrialized countries, but little is known about socioeconomic factors affecting the risk of infection.200818300694
insecticidal properties and microbial contaminants in a spodoptera exigua multiple nucleopolyhedrovirus (baculoviridae) formulation stored at different temperatures.the spodoptera exigua (hübner) multiple nucleopolyhedrovirus (semnpv) is currently being tested as a biological insecticide for use in greenhouse crops in southern spain. we performed a study in which semipurified semnpv occlusion bodies (obs) were formulated in phosphate-buffered saline, ph 6.5, with 5% (vol:vol) glycerol and 0.15% (wt:vol) sorbic acid, and they were stored at -20, 4, or 25 degrees c during 18 mo. initial aerobic counts (+/-se) averaged 1.4 (+/-0.17) x 10(7) colony-forming unit ...200818330114
on-line monitoring of microbial volatile metabolites by proton transfer reaction-mass spectrometry.a method for analysis of volatile organic compounds (vocs) from microbial cultures was established using proton transfer reaction-mass spectrometry (ptr-ms). a newly developed sampling system was coupled to a ptr-ms instrument to allow on-line monitoring of vocs in the dynamic headspaces of microbial cultures. the novel ptr-ms method was evaluated for four reference organisms: escherichia coli, shigella flexneri, salmonella enterica, and candida tropicalis. headspace vocs in sampling bottles con ...200818245241
prevalence of gastrointestinal bacterial pathogens in a population of zoo animals.faecal prevalence of gastrointestinal bacterial pathogens, including campylobacter, escherichia coli o157:h7, salmonella, shigella, yersinia, as well as arcobacter, were examined in 317 faecal specimens from 44 animal species in belfast zoological gardens, during july-september 2006. thermophilic campylobacters including campylobacter jejuni, campylobacter coli and campylobacter lari, were the most frequently isolated pathogens, where members of this genus were isolated from 11 animal species (1 ...200818331520
eukaryotic expression and antimicrobial spectrum determination of the peptide tachyplesin ii.ta0-a, the gene encoding the mature antimicrobial peptide tachyplesin ii, was engineered to optimize the coding sequence according to codon usage bias in yeast. ta0-a was efficiently expressed in the methylotrophic yeast pichia pastoris strain smd1168. the recombinant peptide ta0 reached 150mg/l after methanol induction for 6 d. ta0 was rapidly purified to homogeneity by a single step of size-exclusion chromatography. the minimal lethal concentrations of ta0 to the escherichia coli strain k12 wa ...200818249136
[shigella spp infections in children living in the metropolitan region, chile, during summer of 2004-2005].shigella spp is a frequent cause of diarrhea in children. antimicrobials decrease the duration of diarrhea and pathogen excretion. however, the increasing resistance limits their therapeutic value.200818259649
the shf gene of a shigella flexneri homologue on the virulent plasmid paa2 of enteroaggregative escherichia coli 042 is required for firm biofilm formation.enteroaggregative escherichia coli (eaec) is an increasingly important cause of diarrhea in both developing and industrialized countries, and is characterized by strong biofilm formation on the intestinal mucosa. sequencing of the virulent plasmid paa2 of the prototype eaec 042 revealed a cluster of three open reading frames (orfs; shf, capu, and virk) ca. 93% identical to a similar cluster located in shigella flexneri. the function of the first orf shf protein is not known, but the closest well ...200818293034
differential activation of human tlr4 by escherichia coli and shigella flexneri 2a lipopolysaccharide: combined effects of lipid a acylation state and tlr4 polymorphisms on signaling.the lipid a of lps activates tlr4 through an interaction with myeloid differentiation protein-2 (md-2) and the degree of lipid a acylation affects tlr4 responsiveness. two tlr4 single nucleotide polymorphisms (asp299gly and thr399ile) have been associated with lps hyporesponsiveness. we hypothesized that the combination of hypoacylation and these single nucleotide polymorphisms would exhibit a compounded effect on tlr4 signaling. hek293t transfectants expressing wild-type or polymorphic tlr4 wer ...200818178854
antimicrobial activity of an endophytic xylaria sp.yx-28 and identification of its antimicrobial compound 7-amino-4-methylcoumarin.an endophytic xylaria sp., having broad antimicrobial activity, was isolated and characterized from ginkgo biloba l. from the culture extracts of this fungus, a bioactive compound p3 was isolated by bioactivity-guided fractionation and identified as 7-amino-4-methylcoumarin by nuclear magnetic resonance, infrared, and mass spectrometry spectral data. the compound showed strong antibacterial and antifungal activities in vitro against staphylococcus aureus [minimal inhibitory concentrations (mic) ...200818092158
phenotypic and molecular characterization of tem-116 extended-spectrum beta-lactamase produced by a shigella flexneri clinical isolate from chickens.extended-spectrum beta-lactamases (esbls) produced by a clinical isolate of shigella flexneri from chickens were detected with confirmatory phenotypic tests of the clinical and laboratory standards institute, and minimum inhibitory concentrations of several antibacterial drugs against the isolate were determined by the twofold dilution method. the genotype and subtype of the esbl-producing s. flexneri isolate were identified by pcr amplifying of esbl genes and dna sequencing analysis. the result ...200818093137
molecular pathogenesis of shigella spp.: controlling host cell signaling, invasion, and death by type iii secretion.shigella spp. are gram-negative pathogenic bacteria that evolved from harmless enterobacterial relatives and may cause devastating diarrhea upon ingestion. research performed over the last 25 years revealed that a type iii secretion system (t3ss) encoded on a large plasmid is a key virulence factor of shigella flexneri. the t3ss determines the interactions of s. flexneri with intestinal cells by consecutively translocating two sets of effector proteins into the target cells. thus, s. flexneri co ...200818202440
a functional genomic yeast screen to identify pathogenic bacterial proteins.many bacterial pathogens promote infection and cause disease by directly injecting into host cells proteins that manipulate eukaryotic cellular processes. identification of these translocated proteins is essential to understanding pathogenesis. yet, their identification remains limited. this, in part, is due to their general sequence uniqueness, which confounds homology-based identification by comparative genomic methods. in addition, their absence often does not result in phenotypes in virulenc ...200818208325
involvement of rna-binding protein hfq in the post-transcriptional regulation of inve gene expression in shigella sonnei.the temperature-dependent regulation of shigella virulence genes is believed to be accomplished at the transcriptional stage by the regulators virf and inve. several lines of evidence herein described indicate that post-transcriptional regulation of inve expression plays a key role in the temperature-dependent regulation of virulence gene expression: (i) a considerable amount of inve mrna continues to be transcribed under low temperature conditions, where the production of inve protein is tightl ...200818156173
selection and validation of a multilocus variable-number tandem-repeat analysis panel for typing shigella spp.the shigella genus has historically been separated into four species, based on biochemical assays. the classification within each species relies on serotyping. recently, genome sequencing and dna assays, in particular the multilocus sequence typing (mlst) approach, greatly improved the current knowledge of the origin and phylogenetic evolution of shigella spp. the shigella and escherichia genera are now considered to belong to a unique genomospecies. multilocus variable-number tandem-repeat (vnt ...200818216214
activities of the frog skin peptide, ascaphin-8 and its lysine-substituted analogs against clinical isolates of extended-spectrum beta-lactamase (esbl) producing bacteria.extended-spectrum beta-lactamase (esbl)-producing gram-negative bacteria are becoming increasingly prevalent and their antibiotic resistance necessitates novel therapeutic intervention. ascaphin-8 is a cationic alpha-helical peptide that shows broad-spectrum antibacterial activity but is also toxic to human erythrocytes (lc(50)= 55 microm). this study assesses the activity of ascaphin-8, and a series of l-lysine-substituted analogs, against a range of clinical isolates of esbl-producing bacteria ...200818068868
quinolone resistance among shigella spp. isolated from travellers returning from india.among 200 isolates of shigella from patients with travellers' diarrhoea, 12 isolates (four isolated in 1995-2000 and eight in 2001-2004) exhibited quinolone resistance. nine of these isolates originated from india. these resistant isolates had at least one amino-acid substitution in gyra. quinolone resistance is increasing in shigella spp. causing travellers' diarrhoea, and particularly among isolates causing diarrhoea in travellers returning from india.200818076667
antibacterial activities and cytotoxicity of terpenoids isolated from spirostachys africana.spirostachys africana sond. stem bark is used traditionally for the treatment of diarrhoea and dysentery in limpopo province of south africa. bioassay-guided fractionation of ethanolic extract from bark of spirostachys africana led to the isolation of four known compounds, two triterpenoids, compound 1 [d-friedoolean-14-en-oic acid (3-acetyl aleuritolic acid)] and compound 2 (lupeol), and two diterpenes, compound 3 [ent-2,6alpha-dihydroxy-norbeyer-1,4,15-trien-3-one (diosphenol 2)] and compound ...200818191928
cmy-2-type plasmid-mediated ampc beta-lactamase finally emerging in argentina. 200818242960
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