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short report: high prevalence of serine protease autotransporter cytotoxins among strains of enteroaggregative escherichia coli.enteroaggregative escherichia coli (eaec) pathogenesis is thought to comprise intestinal colonization followed by the release of enterotoxins and cytotoxins. here, we use a polymerase chain reaction (pcr) to determine the prevalence of 10 genes encoding serine protease autotransporter toxins (spates) in a collection of clinical eaec isolates. eighty-six percent of eaec strains harbored genes encoding one or more class i cytotoxic spate proteins (pet, sat, espp, or siga). two class ii, non-cytoto ...200919190229
molecular epidemiological characteristics of shigella spp. isolated from river narmada during 2005-2006.shigellosis is an acute gastroenteritis caused by shigella species. forty isolates of shigella spp. were obtained from the river narmada during 2005-2006. twenty-three isolates were identified as s. flexneri, 10 as s. sonnei, and seven as s. dysenteriae on the basis of biochemical tests and serotyping. all the isolates harbored at least one plasmid (range: 1-4) and exhibited 12 distinct plasmid profile patterns. out of 40 isolates, 90% were found to be resistant against more than two antibiotics ...200919192746
the ipac carboxyterminal effector domain mediates src-dependent actin polymerization during shigella invasion of epithelial cells.shigella, the causative agent of bacillary dysentery, invades epithelial cells by locally reorganizing the actin cytoskeleton. shigella invasion requires actin polymerization dependent on the src tyrosine kinase and a functional bacterial type iii secretion (t3s) apparatus. using dynamic as well as immunofluorescence microscopy, we show that the t3s translocon component ipac allows the recruitment of the src kinase required for actin polymerization at bacterial entry sites during the initial sta ...200919165331
crystal structure analysis and in silico pka calculations suggest strong pka shifts of ligands as driving force for high-affinity binding to tgt.a novel ligand series is presented to inhibit trna-guanine transglycosylase (tgt), a protein with a significant role in the pathogenicity mechanism of shigella flexneri, the causative agent of shigellosis. the enzyme exchanges guanine in the wobble position of trna(asn,asp,his,tyr) against a modified base. to prevent the base-exchange reaction, several series of inhibitors have already been designed, synthesized, and tested. one aim of previous studies was to address a hydrophobic pocket with di ...200919199329
streptococcus-, shigella-, and listeria-induced autophagy.autophagy has recently been described as an intrinsic host defense system for recognizing and eliminating intracellular-invading bacterial pathogens. some cytoplasmic-invading bacteria are trapped through the process of autophagy and are ultimately degraded within autolysosomal compartments. however, others exhibit highly evolved maneuvers for circumventing autophagic recognition and are capable of surviving and replicating within the cytoplasm. in this chapter, we describe bacterial infectious ...200919200893
a synthetic carbohydrate-protein conjugate vaccine candidate against shigella flexneri 2a infection.the protective ag of shigella, the gram-negative enteroinvasive bacterium causing bacillary dysentery, or shigellosis, is its o-specific polysaccharide (o-sp) domain of the lps, the major bacterial surface component. as an alternative to the development of detoxified lps-based conjugate vaccines, recent effort was put into the investigation of neoglycoproteins encompassing synthetic oligosaccharides mimicking the protective ags of the o-sp. we previously reported that when coupled to tetanus tox ...200919201878
development of prophylactic recombinant hpv58-attenuated shigella live vector vaccine and evaluation of its protective efficacy and immunogenicity in the guinea pig keratoconjunctivitis model.to develop a prophylactic recombinant hpv58l1-attenuated shigella live vector vaccine and evaluate its protective efficacy and immunogenicity in the guinea pig keratoconjunctivitis model, the hpv58l1 gene was cloned into vector pucmt, and then subcloned into the suicide vector pcvd442. the recombinant plasmid pcvd442-hpv58l1 was introduced into attenuated shigella (sf301:deltavirg) with the helper plasmid prk2013 by filter mating. the positive colonies were harvested and confirmed by polymerase ...200919204831
the clinical course of postinfectious irritable bowel syndrome: a five-year follow-up study.irritable bowel syndrome (ibs) is a common disorder seen in general practice. bacterial gastroenteritis has been known to be a risk factor for ibs. we investigated the clinical course, risk factors, and prognosis of postinfectious ibs (pi-ibs) 5 years after shigella infection.200919262407
the mere protein encoded by transposon tn21 is a broad mercury transporter in escherichia coli.in order to clarify the physiological role of the mere gene of transposon tn21, a pe4 plasmid that contained the merr gene of plasmid pmr26 from pseudomonas strain k-62, and the mere gene of tn21 from the shigella flexneri plasmid nr1 (r100) was constructed. bacteria with plasmid pe4 (merr-o/p-mere) were more hypersensitive to ch(3)hg(i) and hg(ii), and took up significantly more ch(3)hg(i) and hg(ii), than the isogenic strain. the mere protein encoded by pe4 was localized in the membrane cell f ...200919265693
high-let ion radiolysis of water: oxygen production in tracks.it is known that molecular oxygen is a product of the radiolysis of water with high-linear energy transfer (let) radiation, a result that is of particular significance in radiobiology and of practical relevance in radiotherapy. in fact, it has been suggested that the radiolytic formation of an oxygenated microenvironment around the tracks of high-let heavy ions is an important factor in their enhanced biological efficiency in the sense that this may be due to an "oxygen effect" by o(2) produced ...200919267566
the effects of the bacterial interaction with visible-light responsive titania photocatalyst on the bactericidal performance.bactericidal activity of traditional titanium dioxide (tio2) photocatalyst is effective only upon irradiation by ultraviolet light, which restricts the potential applications of tio2 for use in our living environments. recently carbon-containing tio2 was found to be photoactive at visible-light illumination that affords the potential to overcome this problem; although, the bactericidal activity of these photocatalysts is relatively lower than conventional disinfectants. evidenced from scanning e ...200919272171
efficient synthesis of six tri- to hexasaccharide fragments of shigella flexneri serotypes 3a and/or x o-antigen, including a study on acceptors containing n-trichloroacetylglucosamine versus n-acetylglucosamine.six tri- to hexasaccharide fragments of the {2)-[alpha-d-glcp-(1-->3)]-alpha-l-rhap-(1-->2)-alpha-l-rhap-(1-->3)-[ac-->2]-alpha-l-rhap-(1-->3)-beta-d-glcpnac-(1-->}(n) polymer ([(e)ab(ac)cd](n)) were synthesized as their propyl glycosides. all targets share the (e)ab sequence. following a thorough investigation on the use of n-trichloroacetylglucosamine- versus n-acetylglucosamine-containing tri- and tetrasaccharide acceptors, the successful strategy was based on an efficient combination of the ...200919278208
foodborne outbreaks, austria 2007.in 2007 austria reported a total of 438 foodborne outbreaks affecting 1715 people, including 286 hospitalized patients and one death. salmonella spp. and campylobacter spp. accounted for 95% of all reported outbreaks. forty-eight (11%) of the 438 austrian outbreaks were acquired abroad. of the 390 domestically acquired foodborne outbreaks, bacterial infection caused 376, viruses (norovirus and 1-time hepatitis a virus) caused 11, and intoxications (staphylococcus aureus enterotoxins, alkaloid to ...200919280130
a food-borne outbreak of shigella sonnei gastroenteritis, austria, 2008.we report on the first foodborne outbreak of shigella sonnei described in austria. on july 14 2008, ages was informed of a cluster of 22 laboratory-confirmed cases of infection with s. sonnei restricted to public health district x in the province of salzburg. all cases had attended a youth-group trip to a small village in the province of tyrol from july 7 to july 9. an outbreak case among the trip participants was a person who (1) attended the trip and (2) fell ill with diarrhea in the period be ...200919280143
life on the inside: the intracellular lifestyle of cytosolic bacteria.bacterial pathogens exploit a huge range of niches within their hosts. many pathogens can invade non-phagocytic cells and survive within a membrane-bound compartment. however, only a small number of bacteria, including listeria monocytogenes, shigella flexneri, burkholderia pseudomallei, francisella tularensis and rickettsia spp., can gain access to and proliferate within the host cell cytosol. here, we discuss the mechanisms by which these cytosolic pathogens escape into the cytosol, obtain nut ...200919369949
tri-county comprehensive assessment of risk factors for sporadic reportable bacterial enteric infection in children.the aim of this study was to determine risk factors for childhood sporadic reportable enteric infection (rei) caused by bacteria, specifically campylobacter, salmonella, escherichia coli o157, or shigella (rei-b).200919281302
application of a multiplex pcr assay for the detection of shigella, escherichia coli and shiga toxin-producing esch. coli in milk.a multiplex pcr (mpcr) assay using previously known genetic markers of shigella, escherichia coli and shiga-toxic esch. coli was standardized. uida gene was targeted for the common detection of esch. coli and shigella, whereas ipah and stx1 genes were used as markers for the detection of shigella and shiga-toxin producing strains, respectively. the standardized assays detected the target organism specifically and selectively. the mpcr developed by combining all the three reactions generated spec ...200919281632
antimicrobial activity of the methanolic extract and compounds from morus mesozygia stem bark.this study was aimed at investigating the antimicrobial activity of the methanolic extract (mmb) and compounds isolated from the stem bark of morus mesozygia, namely 3beta-acetoxyurs-12-en-11-one (1), moracin q (2), moracin t (3), artocarpesin (4), cycloartocarpesin (5), moracin r (6), moracin u (8), moracin c (9), and moracin m (10).200919450674
diagnosis and treatment of acute or persistent diarrhea.studies of microbial pathogens and the toxins they produce are important for determining the mechanisms by which they cause disease and spread throughout a population. some bacteria produce secretory enterotoxins (such as cholera toxin or the heat-labile or stable enterotoxins produced by escherichia coli) that invade cells directly. others invade cells or produce cytotoxins (such as those produced by shigella, enteroinvasive e coli, or clostridium difficile) that damage cells or trigger host re ...200919457416
molecular typing methodologies for microbial source tracking and epidemiological investigations of gram-negative bacterial foodborne pathogens.gram-negative bacterial foodborne pathogens are a worldwide cause of morbidity and mortality. the ability to carry out epidemiological investigations to determine the primary sources of bacterial contamination is important to improve public health. multiple methods are available for bacterial source tracking and to determine the distribution of pathogens isolated from sick patients. the molecular based typing methods available fall into three general categories: those based on restriction analys ...200919460308
metabolic control through ornithine and uracil of epithelial cell invasion by shigella flexneri.this paper shows that compounds in defined growth media strongly influence the expression of the effectors of virulence in the human invasive pathogen shigella flexneri. ornithine in conjunction with uracil reduces the haemolytic ability of wild-type cultures more than 20-fold and the expression of the type iii secretion system more than 8-fold, as monitored by an mxic : : lacz transcriptional reporter. mxic gene expression is further decreased by the presence of methionine or branched-chain ami ...200919460819
design, synthesis, and immunochemical characterization of a chimeric glycopeptide corresponding to the shigella flexneri y o-polysaccharide and its peptide mimic mdwnmhaa.two glycopeptide chimeras corresponding to the shigella flexneri y o-polysaccharide and its peptide mimic were designed in an attempt to improve the binding affinity by increasing the entropy of binding relative to the original octapeptide mimic of the o-polysaccharide. the design was based on the x-ray crystal structures of a monoclonal antibody sya/j6 in complex with its cognate ligands, a pentasaccharide corresponding to the s. flexneri y o-polysaccharide and the octapeptide mimic, mdwnmhaa. ...200919467535
rapid detection of intestinal pathogens in fecal samples by an improved reverse dot blot method.to develop a new, rapid and accurate reverse dot blot (rdb) method for the detection of intestinal pathogens in fecal samples.200919469006
incidence of multiple antibiotic resistant gram-negative bacteria isolated from surface and underground water sources in south western region of nigeria.in most rural and urban settlements, particularly in nigeria, wells, spring, streams or rivers and lakes serves as major sources of water supply for drinking and other domestic purposes. unfortunately, many of the available water sources are not potable without some form of treatment which is seldom available in most settings. the use of untreated surface water sources for drinking and for domestic purposes remains a major threat to public health as these could serve as reservoirs the for transf ...200919474486
[norovirus infection in general hospitals for adults].to determine the role of noroviruses in the rise of hospital outbreaks of acute intestinal infections (aii), to study clinical and epidemiological aspects of hospital noroviral infection.200919514424
involvement of rna-binding protein hfq in the osmotic-response regulation of inve gene expression in shigella sonnei.the expression of type iii secretion system (ttss) in shigella is regulated in response to changes in environmental osmolarity and temperature. temperature-dependent regulation of virf, the master regulator of ttss synthesis, is believed to occur at the transcriptional level. we recently demonstrated, however, that ttss synthesis also involves post-transcriptional regulation of the synthesis of inve, a target of virf and key regulator of ttss synthesis. the mrna levels of inve (virb) are stable ...200919476612
ipab-ipgc interaction defines binding motif for type iii secretion translocator.the delivery of virulence factors into host cells through type iii secretion systems is essential for enterobacterial pathogenesis. molecular chaperones bind specifically to virulence factors in the bacterial cytosol before secretion. invasion plasmid gene c (ipgc) is a chaperone that binds 2 essential virulence factors of shigella: invasion plasmid antigens (ipa) b and c. here, we report the crystal structure of ipgc alone and in complex with the chaperone binding domain (cbd) of ipab. the chap ...200919478065
comparison of acute bloody and watery diarrhea: a case control study.the clinical and laboratory findings of 290 cases of bloody diarrhea who presented to the department of diarrhea training and treatment between june 1998 and may 2002 were investigated, and compared to those of two consecutive cases who had watery diarrhea. the bloody diarrhea group had higher mean age, higher frequencies of diarrhea, lower frequencies of vomiting, and shorter durations of diarrhea at the time of admission as compared to the watery diarrhea group. the number of cases using antib ...200919480324
laboratory-acquired infections.laboratory-acquired infections due to a wide variety of bacteria, viruses, fungi, and parasites have been described. although the precise risk of infection after an exposure remains poorly defined, surveys of laboratory-acquired infections suggest that brucella species, shigella species, salmonella species, mycobacterium tuberculosis, and neisseria meningitidis are the most common causes. infections due to the bloodborne pathogens (hepatitis b virus, hepatitis c virus, and human immunodeficiency ...200919480580
reactive arthritis: clinical aspects and medical management.reactive arthritis (rea) is an inflammatory arthritis that arises after certain gastrointestinal or genitourinary infections, representing a classic interplay between host and environment. it belongs to the group of arthritidies known as the spondyloarthropathies. the classic syndrome is a triad of symptoms, including the urethra, conjunctiva, and synovium; however, the majority of patients do not present with this triad. diagnostic criteria for rea exist, but data suggest new criteria are neede ...200919480995
analytical comparison of nine pcr primer sets designed to detect the presence of escherichia coli/shigella in water samples.the analytical performance of 9 different pcr primer sets designed to detect escherichia coli and shigella in water has been evaluated in terms of ubiquity, specificity, and analytical detection limit. of the 9 pcr primer sets tested, only 3 of the 5 primer sets targeting uida gene and the primer set targeting tuf gene amplified dna from all e. coli strains tested. however, of those 4 primer sets, only the primer set targeting the tuf gene also amplified dna from all shigella strains tested. for ...200919482328
protein interaction platforms: visualization of interacting proteins in yeast.here we describe the protein interaction platform assay, a method for identifying interacting proteins in saccharomyces cerevisiae. this assay relies on the reovirus scaffolding protein microns, which forms large focal inclusions in living cells. when a query protein is fused to microns and potential interaction partners are fused to a fluorescent reporter, interactors can be identified by screening for yeast that display fluorescent foci.200919483691
lack of antimicrobial activity by the antiretroviral drug nevirapine against common bacterial pathogens. 200919487448
bacteria hijack integrin-linked kinase to stabilize focal adhesions and block cell detachment.the rapid turnover and exfoliation of mucosal epithelial cells provides an innate defence system against bacterial infection. nevertheless, many pathogenic bacteria, including shigella, are able to surmount exfoliation and colonize the epithelium efficiently. here we show that the shigella flexneri effector ospe (consisting of ospe1 and ospe2 proteins), which is highly conserved among enteropathogenic escherichia coli, enterohaemorrhagic e. coli, citrobacter rodentium and salmonella strains, rei ...200919489119
pulsed-field gel electrophoresis for molecular epidemiology of food pathogens.foodborne diseases due to well-recognized pathogens have emerged as an important and growing public health problem with a significant impact on health. molecular methods for subtyping these microorganisms have become a valid adjunct to the traditional techniques employed in most laboratories. one such molecular technique for the detection and identification of food pathogens is pulsed-field gel electrophoresis (pfge). this method separates large dna molecules by the use of an alternating electri ...200919521867
sporadic paediatric diarrhoeal illness in urban and rural sites in nyanza province, kenya.investigate differences in the infectious aetiology, health seeking behaviour, and provider practices with regard to diarrhoeal illness among children presenting to urban versus rural clinics in western kenya.200920575313
screening of antibacterial potentials of some medicinal plants from melghat forest in india.cyperus rotundus, caesalpinia bonducella, tinospora cordifolia, gardenia gummifera, ailanthus excelsa, acacia arabica, embelia ribes and ventilago maderspatana from melghat forest were screened for their antibacterial potential against escherichia coli, staphylococcus aureus, klebsiella pneumoniae, proteus vulgaris, salmonella typhi, shigella flexneri, salmonella paratyphi, salmonella typhimurium, pseudomonas aeruginosa, enterobacter aerogenes by disc diffusion method. out of these medicinal pla ...200920448847
association of water-borne diseases morbidity pattern and water quality in parts of ibadan city, nigeria.occurrence of diarrhoea and other water-borne diseases in cities of developing countries has been on the increase over the decades largely due to unsafe water, inadequate sanitation and poor hygiene among human population. this study examined the relationship between the spatial pattern of water-borne diseases vis-a-vis water quality in parts of ibadan city in nigeria. data on 1334 cases of various water-borne diseases was collected from eight public hospitals with catchments covering the study ...200920734698
pcr targeting of antibiotic resistant bacteria in public drinking water of lahore metropolitan, pakistan.to investigate the prevalence of kanamycin (kan) and ampicillin (amp) resistant bacteria in public drinking water.200920337218
prevalence and antimicrobial resistance of diarrheagenic escherichia coli and shigella species associated with acute diarrhea in tehran, iran.a study was performed to determine the prevalence and antimicrobial resistance of shigella species and diarrheagenic escherichia coli isolates cultured from patients with acute diarrhea in tehran, iran. between may 2003 and may 2005, 1120 diarrheal specimens were collected and assayed for bacterial enteropathogens by conventional and molecular methods. etiological agents were isolated from 564 (50.3%) specimens, and included 305 (54%) e coli, 157 (27.8%) shigella species, and 102 (18%) from othe ...200920808457
[shigella strategy for host defense and mucosal infection]. 200921089529
shigella species and serotypes among clinical isolates in thailand from 2001 to 2005.to study the species and the serotypes of the clinical isolates of shigella obtained from patients in thailand.200921298848
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
antibacterial antibodies for some enterobacteria in sera of patients with reactive arthritis and other rheumatoid diseases.the presence of the specific antibodies for some enterobacteria--yersinia, salmonella and shigella was investigated in patients hospitalized in the period 2000-2007 with reactive arthritis and other rheumatoid diseases. the antibacterial antibodies in the diagnosis titres were found in 172 out of 1102 (15.6%) patients. increased antibodies levels to yersinia were detected in the sera from 113 (65.7%) of the 172 patients, for shigella in 47 (27.3%) and for salmonella in 12 (7.0%) cases. from all ...200819284164
antimicrobial activity of some macrophytes from lake manzalah (egypt).the antimicrobial activities of aqueous and organic solvents (chloroform, ethanol and methanol) extracts of four plants ceratophyllum demersum l., eichhornia crassipes, potamogeton crispus and potamogeton pectinatus were tested in vitro against seventeen different microorganisms including gram-positive and gram-negative bacteria and fungi. nine of these identified organisms were obtained from different sources, bacillus subtilis 1020, bacillus cereus 1080, staphylococcus aureus, erwinia carotovo ...200819205264
intestinal bacterial and parasitic infections among food handlers in a tertiary care hospital of north india.intestinal infection is still an important public health problem in developing countries like india. food handlers may be infected by a wide range of enteropathogens and have been implicated in the transmission of many infections to the public in the community and to patients in hospitals.200819323089
interactions of the intestinal epithelium with the pathogen and the indigenous microbiota: a three-way crosstalk.the mucosal surfaces of the gastrointestinal tract harbor a vast number of commensal microbiota that have coevolved with the host, and in addition display one of the most complex relationships with the host. this relationship affects several important aspects of the biology of the host including the synthesis of nutrients, protection against infection, and the development of the immune system. on the other hand, despite the existence of several lines of mucosal defense mechanisms, pathogenic org ...200819259328
microbiological quality and safety of rastrineobola argentea retailed in kisumu town markets, kenya.to investigate faecal contamination and safety of rastrineobola argentea sold in retail markets in kisumu town.200819537428
safety and colonization of two novel virg(icsa)-based live shigella sonnei vaccine strains in rhesus macaques (macaca mulatta).shigella are gram-negative bacterium that cause bacillary dysentery (shigellosis). symptoms include diarrhea and discharge of bloody mucoid stools, accompanied by severe abdominal pain, nausea, vomiting, malaise, and fever. persons traveling to regions with poor sanitation and crowded conditions become particularly susceptible to shigellosis. currently a vaccine for shigella has not been licensed in the united states, and the organism quickly becomes resistant to medications. during the past 10 ...200819793462
comparative study of leaf and stem bark extracts of parkia biglobosa against enterobacteria.hydroethanolic and aqueous extracts of leaf and stem bark of parkia biglobosa (jacq) benth. (mimosaceae) were tested against clinical isolates escherichia coli, salmonella typhi, shigella dysenteriae and enterococcus faecalis, and corresponding collection strains e. coli cip 105 182, salmonella enterica cip 105 150, shigella dysenteriae cip 54-51 and enterococcus faecalis cip 103 907. discs of gentamicin, a broad spectrum antibiotic were used as positive controls. the results showed that all the ...200820161943
antimicrobial activity of various extracts of ocimum basilicum l. and observation of the inhibition effect on bacterial cells by use of scanning electron microscopy.the antimicrobial activities of chloroform, acetone and two different concentrations of methanol extracts of ocimum basilicum l. were studied. these extracts were tested in vitro against 10 bacteria and 4 yeasts strains by the disc diffusion method. the results indicated that the methanol extracts of o. basilucum exhibited the antimicrobial activity against tested microorganisms. while the chloroform and acetone extracts had no effect, the methanol extracts showed inhibition zones against strain ...200820161958
contamination of herbal medicinal products marketed in kaduna metropolis with selected pathogenic bacteria.the study aimed to evaluate the bacterial contamination of powdered herbal medicinal preparations sourced from identified herbal retail outlets in different parts of kaduna metropolis. the assessments of the contamination of the herbal products were carried out using standard procedures: total aerobic bacterial plate count, measurement of some physical parameters, isolation and characterization of selected bacterial pathogens etc. the results showed that out of a total of 150, 70 (46.67%) herbal ...200820162044
synthesis, antimicrobial and antiinflammatory activity of 2,5-disubstituted-1,3,4-oxadiazoles.in the present study, 2,5-disubstituted-1,3,4-oxadiazoles (3a-o) have been synthesized by the condensation of 4-methoxybenzohydrazide (1) with different aromatic acids (2a-o) in presence of phosphoryl chloride. the structural assignment of this compound (3a-o) has been made on the basis of elemental analysis, uv, ir, (1)h nmr and mass spectral data. the synthesized compounds were screened for their in vitro growth inhibiting activity against different strains of bacteria and fungi viz., staphylo ...200820390080
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
full structural characterization of shigella flexneri m90t serotype 5 wild-type r-lps and its delta galu mutant: glycine residue location in the inner core of the lipopolysaccharide.shigella flexneri is a gram-negative bacterium responsible for serious enteric infections that occur mainly in the terminal ileum and colon. high interest in shigella, as a human pathogen, is driven by its antibiotic resistance and the necessity to develop a vaccine against its infections. vaccines of the last generation use carbohydrate moieties of the lipopolysaccharide as probable candidates. for this reason, the primary structure of the core oligosaccharide from the r-lps produced by s. flex ...200818174310
the origin of a novel gene through overprinting in escherichia coli.overlapped genes originate by a) loss of a stop codon among contiguous genes coded in different frames; b) shift to an upstream initiation codon of one of the contiguous genes; or c) by overprinting, whereby a novel open reading frame originates through point mutation inside an existing gene. although overlapped genes are common in viruses, it is not clear whether overprinting has led to new genes in prokaryotes.200818226237
ph sensitivity of type iii secretion system tip proteins.many pathogenic gram-negative bacteria employ type iii secretion systems to transport proteins into the host cell membrane and cytoplasm to subvert normal cellular functions. the type iii secretion apparatus consists of a basal body spanning the inner and outer bacterial membranes and a needle which extends away from the bacterium. recent work has found that a special class of proteins localizes to the tip of the needle to control secretion of effector proteins. five of these tip proteins are ip ...200818175320
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
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
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
timeliness of enteric disease surveillance in 6 us states.we reviewed timeline information for a sample of salmonella spp., shigella spp., campylobacter spp., and escherichia coli o157:h7 cases and all confirmed foodborne outbreaks reported in 6 states during 2002. increasing the timeliness of case follow-up, molecular subtyping, and linkage of results are critical to reducing delays in the investigation of foodborne outbreaks.200818258128
diarrheagenic escherichia coli and shigella strains isolated from children in a hospital case-control study in hanoi, vietnam.this case-control study detected and characterized shigella and diarrheagenic escherichia coli (dec) types among vietnamese children less than 5 years old. in 249 children with diarrhea and 124 controls, shigella spp. was an important cause of diarrhea (p < 0.05). we used multiplex pcr and dna probes to detect enteroinvasive e. coli (eiec), enteroaggregative e. coli (eaggec), enteropathogenic e. coli (epec), attaching and effacing e. coli (a/eec), verocytotoxin-producing e. coli (vtec), and ente ...200818174300
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
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
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
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
nitrate and bacterial contamination in well waters in vinh phuc province, vietnam.measurements were made of the nitrate concentration and bacterial contamination of groundwater samples taken from both dug wells and bores in the commune of hop thinh', in the administrative district of vinh phuc, vietnam. a significant number (18%) of samples had nitrate concentrations in excess of the who guideline value for drinking water of 50 mg l(-1), with a higher proportion in the dug wells (29%) than the bores (3.8%). high concentrations of thermotolerant coliforms were found in many of ...200818209289
nlrx1 is a mitochondrial nod-like receptor that amplifies nf-kappab and jnk pathways by inducing reactive oxygen species production.nod-like receptors (nlrs) are a family of intracellular sensors of microbial- or danger-associated molecular patterns. here, we report the identification of nlrx1, which is a new member of the nlr family that localizes to the mitochondria. nlrx1 alone failed to trigger most of the common signalling pathways, including nuclear factor-kappab (nf)-kappab- and type i interferon-dependent cascades, but could potently trigger the generation of reactive oxygen species (ros). importantly, nlrx1 synergis ...200818219313
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
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
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
traveler's myopericarditis.colitis caused by shigella is an uncommon etiology of infectious diarrhea in developed countries, usually presenting as traveler's diarrhea. aside from clinical intestinal manifestations, shigellosis can present with a wide variety of extra-intestinal symptoms. we present the case of a 38-year-old man with diarrhea, fever, and chest pain that started after a holiday in cape verde (africa). blood samples revealed an increase in cardiac enzymes. an electrocardiogram revealed a widespread elevation ...200818249314
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
a comparative synteny map of burkholderia species links large-scale genome rearrangements to fine-scale nucleotide variation in prokaryotes.genome rearrangement events, including inversions and translocations, are frequently observed across related microbial species, but the impact of such events on functional diversity is unclear. to clarify this relationship, we compared 4 members of the gram-negative burkholderia family (burkholderia pseudomallei, burkholderia mallei, burkholderia thailandensis, and burkholderia cenocepacia) and identified a core set of 2,590 orthologs present in all 4 species (metagenes). the metagenes were orga ...200818162473
role of escherichia coli in acute diarrhoea in tribal preschool children of central india.five hundred and eighty preschool children belonging to tribal areas of madhya pradesh were followed up daily for the presence of diarrhoea for a period of 1 year. in all, 1236 episodes of diarrhoea were recorded with an average of 2.13 episodes per child per year. stool samples were collected during 780 episodes. they were cultured to isolate escherichia coli as well as non-e. coli enteropathogens. ten different genes were detected to identify all diarrhoeagenic e. coli using multiplex polymera ...200818173783
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
muramylpeptide shedding modulates cell sensing of shigella flexneri.bacterial infections trigger the activation of innate immunity through the interaction of pathogen-associated molecular patterns (pamps) with pattern recognition molecules (prms). the nucleotide-binding oligomerization domain (nod) proteins are intracellular prms that recognize muramylpeptides contained in peptidoglycan (pgn) of bacteria. it is still unclear how nod1 physically interacts with pgn, a structure internal to the gram-negative bacterial envelope. to contribute to the understanding of ...200818042252
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
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
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
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
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
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
[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
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
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
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
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
a comparison of self-reported joint symptoms following infection with different enteric pathogens: effect of hla-b27.we conducted a case-case comparison study to estimate the attack-rate of reactive joint pain (jprea) following intestinal infections, and evaluated whether the susceptibility and severity of joint symptoms was associated with the tissue-type hla-b27.200818203313
phase 1 clinical trial of live attenuated shigella dysenteriae type-1 deltaicsa deltaent deltafep deltastxa:hgr oral vaccine sc599 in healthy human adult volunteers.twenty-eight adults received between 10(2) and 10(8)colony forming units of live shigella dysenteriae type-1 vaccine sc599, attenuated by deletion of invasion (icsa), iron chelation (ent, fep) and shiga toxin a-subunit (stxa) genes, followed by ciprofloxacin on day 4. dose-independent diarrhea or change in bowel habit was seen in 3 subjects, without dysentery, vaccinaemia or serious adverse events. hematology and biochemical parameters were unchanged. doses of 10(5) or greater induced dose-indep ...200818207287
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
regulation of expression and secretion of nleh, a new non-locus of enterocyte effacement-encoded effector in citrobacter rodentium.together with enterohemorrhagic escherichia coli and enteropathogenic escherichia coli, citrobacter rodentium is a member of the attaching-and-effacing (a/e) family of bacterial pathogens. a/e pathogens use a type iii secretion system (t3ss) to translocate an assortment of effector proteins, encoded both within and outside the locus of enterocyte effacement (lee), into the colonized host cell, leading to the formation of a/e lesions and disease. here we report the identification and characteriza ...200818223087
[shigellosis outbreak with 146 cases related to a fair].on september 3, 2005, the ciudad real public health service (spain) received a report of 20 cases of gastroenteritis in the municipality of daimiel. we conducted an investigation to determine the cause or causes of the outbreak and to implement control measures. most of the cases involved young people who visited the municipality's fair.200818261440
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
diverse antimicrobial killing by enterococcus faecium e 50-52 bacteriocin.an effective bacteriocin was identified and characterized. lactic acid bacteria were screened against campylobacter jejuni. one bacteriocin producer, enterococcus faecium (nrrl b-30746), was studied. the isolate was grown, and the bacteriocin was purified to single-band homogeneity. biochemical traits indicated that the peptide was a class iia bacteriocin, and it was named e 50-52. the bacteriocin had a molecular weight of 3339.7 and an isoelectric point of 8.0. the minimal inhibitory concentrat ...200818293921
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