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cytokine release induced by killed bacteria associated with anti-ifn-gamma antibody in shigella infection.an effort was made to analyze the effect of in vitro stimulation on macrophages using killed shigella dysenteriae type-1 (ksd1) coupled with anti-interferon gamma (anti-ifn-gamma) antibody. the stimulated macrophages were co-cultured with primed or non-primed t-cells from shigella infected patients. t-cell cultures were also established by co-culturing ksd1 coupled with or without pha stimulated macrophages. emulsified ksd1 coupled with anti-ifn-gamma antibody was found to act as a potent immuno ...200515894487
antibacterial activity of the essential oil from cymbopogon nervatus inflorescence.antibacterial activity of essential oil of dried inflorescence of cymbopogon nervatus was investigated. the essential oil remarkably inhibited the growth of tested bacteria except for salmonella typhi. the maximum activity was against shigella dysenteriae and klebsiella pneumoniae.200515896926
a gene encoding l-methionine gamma-lyase is present in enterobacteriaceae family genomes: identification and characterization of citrobacter freundii l-methionine gamma-lyase.citrobacter freundii cells produce l-methionine gamma-lyase when grown on a medium containing l-methionine. the nucleotide sequence of the hybrid plasmid with a c. freundii ecori insert of about 3.0 kbp contained two open reading frames, consisting of 1,194 nucleotides and 1,296 nucleotides, respectively. the first one (denoted megl) encoded l-methionine gamma-lyase. the enzyme was overexpressed in escherichia coli and purified. the second frame encoded a protein belonging to the family of perme ...200515901718
antidiarrhoeal activity of the methanol extract of the barks of xylocarpus moluccensis in castor oil- and magnesium sulphate-induced diarrhoea models in mice.the methanol (meoh) extract of the barks of xylocarpus moluccensis, and different fractions of this extract were studied for antidiarrhoeal activity using castor oil- and magnesium sulphate-induced diarrhoea models in mice. at the doses of 250 and 500 mg/kg, the meoh extract showed significant antidiarrhoeal activity in both models. the etoac fraction (eaf) and the residual meoh fraction (rmf) exhibited similar activity using a dose of 250 mg/kg in both models. no antidiarrhoeal activity was obs ...200515905054
salmonellosis and the food chain in khon kaen, northeastern thailand.non-typhoidal salmonellosis is a major cause of food-borne illness in thailand. specific serotyping of salmonellae, linked with certain foods, can be used to identify outbreaks, transmission, and for surveillance. we aimed to identify the chain of non-typhoidal salmonella transmission from food to humans in five slums, two open markets, four supermarkets and an abattoir in the municipality of khon kaen. during three months representing the cool-dry, hot-dry, and rainy seasons of 2002, culture sa ...200515906654
cryptic plasmid prk2 from escherichia coli w: sequence analysis and segregational stability.cryptic plasmid prk2 of the strain escherichia coli w (atcc 9637), an ancestor of production strains for penicillin g acylase, was sequenced and characterized. based on the data on replication region and origin (ori sequence aac, 924-926nt), the plasmid was classified as cole1-like plasmid. dna sequence analysis revealed five orfs hypothetical products of which shared a significant sequence similarity with putative proteins encoded by dna of plasmid pcole1. orf1 codes for protein rom involved in ...200515907542
quantitative analyses of pollution-indicator and pathogenic bacteria in mumbai waters from ballast water exchange perspective.as large numbers of ships either take in ballast from or discharge their ballast into the mumbai harbor region, it is pertinent to quantify microorganisms of health concerns and suggest on the suitability of water for ballasting purposes. to meet with this main aim, a selected set of general and pathogenic bacterial groups and their seasonal variations were studied from the mumbai harbor area. sampling was carried out during postmonsoon (november 2001), pre-monsoon (april 2002) and monsoon (octo ...200515931993
complete genome sequence of phihsic, a pseudotemperate marine phage of listonella pelagia.the genome for the marine pseudotemperate member of the siphoviridae phihsic has been sequenced using a combination of linker amplification library construction, restriction digest library construction, and primer walking. phihsic enters into a pseudolysogenic relationship with its host, listonella pelagia, characterized by sigmoidal growth curves producing >10(9) cells/ml and >10(11) phage/ml. the genome (37,966 bp; g+c content, 44%) contained 47 putative open reading frames (orfs), 17 of which ...200515933034
antimicrobial-resistant shigella sonnei: limited antimicrobial treatment options for children and challenges of interpreting in vitro azithromycin susceptibility.antimicrobial-resistant shigella sonnei is a growing problem in the united states and poses treatment challenges particularly among children. azithromycin is recommended as an alternative oral agent for shigellosis.200515933557
evolutionary changes of the flhdc flagellar master operon in shigella strains.shigella strains are nonmotile. the master operon of flagellar synthesis, flhdc, was analyzed for genetic damage in 46 shigella strains representing all known serotypes. in 11 strains (b1, b3, b6, b8, b10, b18, d5, f1b, d10, f3a, and f3c) the flhdc operon was completely deleted. pcr and sequence analysis of the flhdc region of the remaining 35 strains revealed many insertions or deletions associated with insertion sequences, and the majority of the strains were found to be defective in their flh ...200515937193
mucosal lymphoid infiltrate dominates colonic pathological changes in murine experimental shigellosis.shigella species are invasive human pathogens that cause acute rectocolitis by triggering a dysregulated inflammatory reaction in the colonic and rectal mucosa. because mice are naturally resistant to shigellosis, there is no mouse model that mimics human disease. we explore the susceptibility of intestinal flora-depleted mice to shigellosis after intragastric infection with shigella strains.200515942903
phosphotidylinositol-3 kinase-mediated signals in mice immunized with the 57 kda major antigenic outer-membrane protein of shigella dysenteriae type 1.antigen-specific t-cell signalling via t-cell antigen receptor stimulation was carried out in balb/c mice immunized with the 57 kda major antigenic component of shigella dysenteriae 1 outer-membrane proteins. in presence of anti-cd3, the 57 kda antigen was found to increase the level of il-2 significantly instead of il-4. il-2 production in t cells was consistent with an increase in intracellular free ca(2+) [(ca(2+))i] concentration. the antigen-specific modulation was observed during t-cell si ...200515947427
epidemiological and microbiological aspects of acute bacterial diarrhea in children from salvador, bahia, brazil.in the few cases of acute childhood diarrhea that require antimicrobial therapy, the correct choice of the drug depends on detailed previous knowledge of local strains. in order to establish such parameters in our city, we reviewed the results of all 260 positive stool cultures of children between 0 and 15 years of age during two years at a pediatric tertiary care facility in salvador, brazil. bacterial strains had been presumptively identified by culturing in selective media and by biochemical ...200515947851
construction of a novel shigella live-vector strain co-expressing cs3 and ltb/stm of enterotoxigenic e.coli.to construct and evaluate a polyvalent recombinant vaccine strain shigella flexneri 2a t32 against enterotoxigenic e.coli (etec).200515948247
expanding the bactericidal action of the food color additive phloxine b to gram-negative bacteria.phloxine b (d&c red no. 28) is a color additive for food, drugs, and cosmetics. it has been previously shown to have anti-staphylococcus aureus activities. in this work, the effect of phloxine b on various gram-negative bacteria and other gram-positive bacteria including bacillus cereus, bacillus thuringiensis, bacillus mycoides, bacillus subtilis, bacillus aureus, salmonella, escherichia coli and shigella was studied, along with the mechanism of anti-microbial activity. in the presence of fluor ...200515949926
epidemic strain shigella dysenteriae type 1 dt66 encodes several drug resistances by chromosome.multiple antibiotic-resistant strains of shigella dysenteriae type 1 were isolated from an epidemic in west bengal, india (1984). during the past two decades, much attention was given to reevaluation of treatment recommendations. however, there are no useful data on drug resistance encoded by chromosome.200515950082
shigella effector ipah9.8 binds to a splicing factor u2af(35) to modulate host immune responses.shigella effectors injected into the host cell via the type iii secretion system are involved in various aspects of infection. here, we show that one of the effectors, ipah9.8, plays a role in modulating inflammatory responses to shigella infection. in murine lung infection model, deltaipah9.8 mutant caused more severe inflammatory responses with increased pro-inflammatory cytokine production levels than did wild-type shigella, which resulted in a 30-fold decrease in bacterial colonization. bind ...200515950937
traveler's diarrhea.acute diarrhea affects millions of persons who travel to developing countries each year. food and water contaminated with fecal matter are the main sources of infection. bacteria such as enterotoxigenic escherichia coli, enteroaggregative e. coli, campylobacter, salmonella, and shigella are common causes of traveler's diarrhea. parasites and viruses are less common etiologies. travel destination is the most significant risk factor for traveler's diarrhea. the efficacy of pretravel counseling and ...200515952437
the use of a genetic algorithm search for molecular mechanics (mm3)-based conformational analysis of oligosaccharides.we have implemented a system called glygal that can perform conformational searches on oligosaccharides using several different genetic algorithm (ga) search methods. the searches are performed in the torsion angle conformational space, considering both the primary glycosidic linkages as well as the pendant groups (c-5-c-6 and hydroxyl groups) where energy calculations are performed using the mm3(96) force field. the system includes a graphical user interface for setting calculation parameters a ...200515780270
policymakers' views regarding the introduction of new-generation vaccines against typhoid fever, shigellosis and cholera in asia.face-to-face interviews and meetings with more than 160 policymakers and other influential professionals in seven large asian countries (bangladesh, china, india, indonesia, pakistan, thailand and vietnam) were conducted to survey opinions regarding the need for, and potential uses of new-generation vaccines against cholera, typhoid fever and shigellosis. despite several barriers to their uptake--notably uncertainty of the burden of enteric diseases; preference for water, sanitation and other en ...200515780724
quantitative microarray-based dna-dna hybridization assay for measuring genetic distances among bacterial species and its application to the identification of family enterobacteriaceae.quantitative dna-dna hybridization to measure the genetic distances among bacterial species is indispensable for taxonomical determination. in the current studies, we developed a method to determine bacterial dna relatedness on a glass microarray. reference dnas representing a total 93 species of enterobacteriaceae were arrayed on a glass microplate, and signal intensities were measured after 2 hr of hybridization with cy3-labeled bacterial dnas. all immobilized dnas from members of the family e ...200515781999
emergence of ctx-m-type beta-lactam resistance in shigella spp. in hong kong. 200515784319
molecular evolution of the lysine decarboxylase-defective phenotype in shigella sonnei.shigella, the etiological agent of the bacillary dysentery, belongs to the extremely diverse species of escherichia coli. in the evolutionary route of shigella from commensal e. coli ancestors towards a pathogenic lifestyle, the critical events have been the acquisition of the pinv plasmid, through horizontal transfer and the inactivation of pre-existing genes. these so-called pathoadaptive mutations affect the expression of genes negatively interfering with the newly acquired functions necessar ...200515790294
alteration in the gyra subunit of dna gyrase and the parc subunit of topoisomerase iv in quinolone-resistant shigella dysenteriae serotype 1 clinical isolates from kolkata, india. 200515793166
surprising dependence on postsegregational killing of host cells for maintenance of the large virulence plasmid of shigella flexneri.low-copy-number plasmids all encode multiple systems to ensure their propagation, including replication, partition (active segregation), and postsegregational killing (psk) systems. psk systems kill those rare cells that lose the plasmid due to replication or segregation errors. psk systems should not be used as the principle means of maintaining the plasmid. the metabolic cost of killing the many cured cells that would arise from random plasmid segregation is far too high. here we describe an i ...200515805523
shigellosis: disease burden, epidemiology and case management. 200515807074
[small treatise on art of warfare... from shigella]. 200515811311
heterogeneity among strains of diffusely adherent escherichia coli isolated in brazil.one hundred twelve diffusely adherent escherichia coli strains isolated from children in a case control study were evaluated for virulence-associated characteristics, serotyping, antibiotic resistance, and plasmid profiles. half of the strains hybridized with the probes for icua (aerobactin) and fimh (type 1 pili); daae (f1845 fimbriae), afa (afimbrial dr adhesin), agg-3a (aggregative adhesion fimbria type iii fimbriae), pap (p fimbriae), asta (east1 toxin), and shet1 (shigella enterotoxin 1) se ...200515815034
comparative imaging of a bacterial surface-located gfp fusion protein by epifluorescence and scanning near-field optical microscopy.icsa is an autotransporter protein that plays a role in the virulence of shigella bacteria. we have examined the cellular localization of a fusion of an icsa fragment to the green fluorescent protein (gfp) expressed in escherichia coli using a dual epifluorescence and scanning near-field optical microscope. by combining the data obtained from far-field with near-field microscopy of the same sample, discrimination between surface-bound fusion proteins and fusion proteins located in the cellular c ...200515817062
cortactin: an achilles' heel of the actin cytoskeleton targeted by pathogens.cortactin is an actin-binding protein and a central regulator of the actin cytoskeleton. importantly, cortactin is also a common target exploited by microbes during infection. its involvement in disease development is exemplified by a variety of pathogenic processes, such as pedestal formation [enteropathogenic and enterohaemorrhagic escherichia coli (epec and ehec)], invasion (shigella, neisseria, rickettsia, chlamydia, staphylococcus and cryptosporidium), actin-based motility (listeria, shigel ...200515817388
oiling the key hole.many bacteria have been found to interact with specialized domains, rich in cholesterol and sphingolipids, of the host plasma membrane, termed lipid rafts. the mechanisms that underlie this interaction are starting to be unravelled. in this issue, hayward et al. show that early effector proteins secreted by type iii secretion harbouring gram-negative bacteria are in fact cholesterol-binding proteins. combined with other recent findings, this work shows that multiple steps leading to infection by ...200515819615
cholesterol binding by the bacterial type iii translocon is essential for virulence effector delivery into mammalian cells.a ubiquitous early step in infection of man and animals by enteric bacterial pathogens like salmonella, shigella and enteropathogenic escherichia coli (epec) is the translocation of virulence effector proteins into mammalian cells via specialized type iii secretion systems (ttsss). translocated effectors subvert the host cytoskeleton and stimulate signalling to promote bacterial internalization or survival. target cell plasma membrane cholesterol is central to pathogen-host cross-talk, but the p ...200515819617
isolation and characterization of provisional serovar shigella boydii e16553 from diarrhoeal patients in bangladesh.in previous studies with strains of the shigella dysenteriae provisional serovars e22383 and e23507 from diarrhoeal stools from patients in bangladesh, two strains of shigella species were identified as shigella boydii provisional serovar e16553 by a reference laboratory. further tests with an antiserum to an international type strain of the provisional serovar e16553 identified an additional 15 isolates. none of the isolates reacted with antisera to the established shigella serovars or any othe ...200515824427
an unusual cluster of dysentery due to shigella dysenteriae type 4 in dhaka, bangladesh. 200515824434
multidrug-resistant shigella sonnei and salmonella enterica serotype typhimurium isolates producing ctx-m beta-lactamases as causes of community-acquired infection in france. 200515825010
shigella sonnei meningitis due to interleukin-1 receptor-associated kinase-4 deficiency: first association with a primary immune deficiency.inherited interleukin-1-receptor-associated kinase-4 (irak-4) deficiency is a recently described immunodeficiency associated with pyogenic bacterial infections and a poor inflammatory response. shigella sonnei is generally associated with outbreaks of rectocolitis in developed countries, but systemic illnesses have occasionally been reported. an underlying primary immunodeficiency has not been found in such cases before now.200515825022
a millennium update on pediatric diarrheal illness in the developing world.more than one billion diarrhea episodes occur every year among children younger than 5 years of age in socioeconomically developing countries causing 2 to 2.5 million deaths. more than twenty viral, bacterial, and parasitic enteropathogens are currently associated with acute diarrhea. rotavirus and diarrheagenic escherichia coli are the most common pathogens responsible for acute diarrhea episodes in children; shigella spp., salmonella spp, campylobacter jejuni/coli, vibrio cholerae, aeromonas s ...200515825143
frequency and characteristics of selected enteropathogens in fecal and rectal specimens from childhood diarrhea in trinidad, 1998-2000.to determine the prevalence and characteristics of selected enteric pathogens in diarrheic children in six counties of the island of trinidad.200515826396
helicobacter pylori infection in anterior uveitis.despite intensive research, the etiology of acute anterior uveitis (aau) remains poorly defined. infection with gram-negative bacteria such as yersinia, salmonella, shigella, and chlamydia have already been suggested as a possible trigger event for aau. helicobacter pylori is also a gram-negative bacterium, shares the lipopolysaccharides, but did not attract the attention of many ophthalmologists until recently. having in mind the relatively high incidence of h. pylori infection in the populatio ...200515827876
fibrino-necrotic typhlitis caused by escherichia fergusonii in ostriches (struthio camelus).two adult ostriches developed anorexia, prostration, and severe hemorrhagic diarrhea, dying 24 hr after the onset of clinical signs. on postmortem examination, the cecal mucosa showed locally extensive areas of hemorrhages and fibrino-necrotic typhlitis with a white-yellowish material covering the mucosal surface. multiple serosal petequial hemorrhages and fibrinous peritonitis were present. histologic examination revealed an intense mononuclear infiltration in the lamina propria and submucosa o ...200515839434
modulation of host cytoskeleton function by the enteropathogenic escherichia coli and citrobacter rodentium effector protein espg.espg is a conserved protein encoded by the locus of enterocyte effacement (lee) of attaching and effacing (a/e) pathogens, including enteropathogenic and enterohemorrhagic escherichia coli and citrobacter rodentium. espg is delivered into infected host cells by a type iii secretion system. the role of espg in virulence has not yet been defined. here we describe experiments that probe the virulence characteristics and biological activities of espg in vitro and in vivo. a c. rodentium espg mutant ...200515845460
ipgb1 is a novel shigella effector protein involved in bacterial invasion of host cells. its activity to promote membrane ruffling via rac1 and cdc42 activation.shigella, the causative agent of bacillary dysentery, is capable of inducing the large scale membrane ruffling required for the bacterial invasion of host cells. shigella secrete a subset of effectors via the type iii secretion system (ttss) into the host cells to induce membrane ruffling. here, we show that ipgb1 is secreted via the ttss into epithelial cells and plays a major role in producing membrane ruffles via stimulation of rac1 and cdc42 activities, thus promoting bacterial invasion of e ...200515849186
use of fatty acid profiles to identify food-borne bacterial pathogens and aerobic endospore-forming bacilli.capillary gas chromatography (gc) with flame ionization detection was used to determine the cellular fatty acid profiles of various food-borne microbial pathogens and to compare the fatty acid profiles of spores and vegetative cells of the same endospore-forming bacilli. fifteen bacteria, representing eight genera (staphylococcus, listeria, bacillus, yersinia, salmonella, shigella, escherichia, and vibrio) and 11 species were used to compare the extracted fatty acid methyl esters (fames). endosp ...200515853428
model for the combined effects of temperature, ph and sodium chloride concentration on survival of shigella flexneri strain 5348 under aerobic conditions.shigella is recognized as a major foodborne pathogen; however, relatively few studies have been reported on its growth and survival characteristics, particularly under conditions relevant to food. a fractional factorial design was used to measure the effects and interactions of temperature (4-37 degrees c), ph (2-6) and nacl (0.5-9%) on survival kinetics of shigella flexneri strain 5348 in bhi broth. stationary-phase cells were inoculated into sterile media to give initial populations of 6-7 log ...200515862880
plasmid partition system of the p1par family from the pwr100 virulence plasmid of shigella flexneri.p1par family members promote the active segregation of a variety of plasmids and plasmid prophages in gram-negative bacteria. each has genes for para and parb proteins, followed by a pars partition site. the large virulence plasmid pwr100 of shigella flexneri contains a new p1par family member: pwr100par. although typical para and parb genes are present, the putative pwr100pars site is atypical in sequence and organization. however, pwr100pars promoted accurate plasmid partition in escherichia c ...200515866921
identification of shigella sonnei biotype g isolates carrying class 2 integrons in italy (2001 to 2003).phenotyping and genotyping have been carried out on 64 epidemic and sporadic isolates of shigella sonnei identified in italy in the years 2001 to 2003. class 2 integron carriage has been also investigated. isolates from four of the five outbreaks and four of six sporadic cases were biotype g, pulsed-field gel electrophoresis type b, and class 2 integron positive, suggesting emergence and spread of an epidemic clone in italy.200515872285
outbreak of shigella flexneri and shigella sonnei enterocolitis in men who have sex with men, quebec, 1999 to 2001. 200515875326
extended-spectrum beta-lactamases in shigella flexneri from argentina: first report of toho-1 outside japan.a 9-year nation-wide survey of the presence of extended-spectrum beta-lactamases (esbls) in shigella flexneri is described. ten of 9033 (0.1%) isolates produced esbls, which were characterized by isoelectric focusing, pcr and dna sequencing. these were ctx-m-2 (five isolates), toho-1 (one isolate), shv-2 (two isolates) and per-2 (two isolates, the first report in s. flexneri world wide). the emergence of each esbl type in s. flexneri was not restricted to a particular region of argentina. toho-1 ...200515878653
shigellosis.shigellosis is a global human health problem. four species of shigella i.e. s. dysenteriae, s. flexneri, s. boydii and s. sonnei are able to cause the disease. these species are subdivided into serotypes on the basis of o-specific polysaccharide of the lps. shigella dysenteriae type 1 produces severe disease and may be associated with life-threatening complications. the symptoms of shigellosis include diarrhoea and/or dysentery with frequent mucoid bloody stools, abdominal cramps and tenesmus. s ...200515880088
characterization of escherichia coli o86 o-antigen gene cluster and identification of o86-specific genes.escherichia coli o86 belongs to the enteropathogenic e. coli (epec) group, some strains of which are pathogens of humans, wild birds and farm animals. the o-antigen gene cluster of e. coli o86 was amplified by long-range pcr using primers based on the housekeeping genes galf and gnd, and then sequenced. genes involved in gdp-fuc and n-acetyl-galactosamine (galnac) synthesis and genes encoding glycosyltransferases, o-unit flippase and o-antigen polymerase were identified on the basis of homology. ...200515778030
survival of shigella boydii 18 in bean salad.a strain of shigella boydii 18 involved in a bean salad outbreak and s. boydii 18 atcc 35966 were used to inoculate bean salad. bean salad samples were stored at 4 or 23 degrees c. at 4 degrees c, the s. boydii survived for the duration of the shelf life of the salad but did not grow. at 23 degrees c, both strains increased by two orders of magnitude by day 2 and decreased rapidly thereafter. this demonstrates the importance of proper storage in preventing the outgrowth of foodborne pathogens.200515830680
considerations for development of whole cell bacterial vaccines to prevent diarrheal diseases in children in developing countries.enteric pathogens constitute a major pediatric threat in the developing world through their impact on morbidity and mortality, physical and cognitive development and cause and effect relationship with malnutrition. although many bacterial pathogens can cause diarrheal diseases, a group of less than 10 including shigella spp., enterotoxigenic escherichia coli (etec), vibrio cholerae, and possibly, campylobacter jejuni account for a significant percentage of these diseases in developing countries. ...200515837361
[bacterial colony as a complex community].information on the adaptive behavior of cells in the process of the formation of a colony by bacteria shigella flexneri rd, used as a model, was obtained with the use of light, transmission and scanning microscopy. the process of the formation of a microcolony was demonstrated; at the initial stages (8 hours) it included 3 groups of cells, and 24 hours later it exhibited sharply defined structurization. the conclusion was made on the possibility of the joint use of different methods of microscop ...200515881929
[antibiotic resistance of shigellae and rationale for etiotropic therapy of shigella infections].the study was aimed at determining sensitivity of shigellae to antibacterial preparations and their clinical effectiveness for correcting recommendations on the empirical therapy of acute shigella infections (asi). the sensitivity of 164 s. flexneri strains and 80 s. sonnei strains, isolated in 1996-2003 in the sumy region, ukraine, was determined with respect to 19 antibacterial preparations: ampicillin (am), tetracycline (te), rifampicin (ri), chloramphenicol (ca), streptomycin (st), fusidin ( ...200515881945
spatial distribution and functional significance of activated vinculin in living cells.conformational change is believed to be important to vinculin's function at sites of cell adhesion. however, nothing is known about vinculin's conformation in living cells. using a forster resonance energy transfer probe that reports on changes in vinculin's conformation, we find that vinculin is in the actin-binding conformation in a peripheral band of adhesive puncta in spreading cells. however, in fully spread cells with established polarity, vinculin's conformation is variable at focal adhes ...200515883197
crystal structure of the copper homeostasis protein (cutcm) from shigella flexneri at 1.7 a resolution: the first structure of a new sequence family of tim barrels. 200515624211
evolutionary genetics of a new pathogenic escherichia species: escherichia albertii and related shigella boydii strains.a bacterium originally described as hafnia alvei induces diarrhea in rabbits and causes epithelial damage similar to the attachment and effacement associated with enteropathogenic escherichia coli. subsequent studies identified similar h. alvei-like strains that are positive for an intimin gene (eae) probe and, based on dna relatedness, are classified as a distinct escherichia species, escherichia albertii. we determined sequences for multiple housekeeping genes in five e. albertii strains and c ...200515629933
structural and genetic characterization of enterohemorrhagic escherichia coli o145 o antigen and development of an o145 serogroup-specific pcr assay.enterohemorrhagic escherichia coli o145 strains are emerging as causes of hemorrhagic colitis and hemolytic uremic syndrome. in this study, we present the structure of the e. coli o145 o antigen and the sequence of its gene cluster. the o145 antigen has repeat units containing three monosaccharide residues: 2-acetamido-2-deoxy-d-glucose (glcnac), 2-acetamidoylamino-2,6-dideoxy-l-galactose, and n-acetylneuraminic acid. it is very closely related to salmonella enterica serovar touera and s. enteri ...200515629947
bacteria spurned by self-absorbed cells. 200515635436
a sensor of the two-component system cpxa affects expression of the type iii secretion system through posttranscriptional processing of inve.the chief function of the cpx two-component system is perceiving various cell envelope stresses, but cpxr is also known to regulate the expression of the type iii secretion system (ttss) of shigella sonnei through transcription of the primary regulator virf. here, we have isolated novel cpxa mutants that exhibited decreased ttss expression from escherichia coli hw1273, which carries the virulence plasmid of s. sonnei. the cpxa deletion strain of hw1273 expressed beta-galactosidase activity level ...200515601694
inactivation of escherichia coli o157:h7 in simulated human gastric fluid.human disease caused by escherichia coli o157:h7 is a function of the number of cells that are present at potential sites of infection and host susceptibility. such infectious doses are a result, in part, of the quantity of cells that are ingested and that survive human host defenses, such as the low-ph environment of the stomach. to more fully understand the kinetics of e. coli o157:h7 survival in gastric fluid, individual e. coli o157:h7 strains were suspended in various media (i.e., saline, c ...200515640204
arrayome: a program for estimating the sizes of microarray-visualized bacterial genomes.arrayome is a new program that calculates the size of genomes represented by microarray-based probes and facilitates recognition of key bacterial strains carrying large numbers of novel genes. protein-coding sequences (cds) that are contiguous on annotated reference templates and classified as 'present' in the test strain by hybridization to microarrays are merged into ics (ics). these ics are then extended to account for flanking intergenic sequences. finally, the lengths of all extended ics ar ...200515640440
campylobacter species and drug resistance in a north indian rural community.campylobacter species are known as agents of enteritis worldwide. however, rural community-based studies on campylobacter infections are lacking. we carried out a prospective case-control study from july to december 2002 to investigate the prevalence and socio-epidemiological determinants of campylobacter infection in a rural community in north india and the drug resistance of campylobacter strains isolated from the community. stool specimens from 348 subjects with diarrhoea and 351 age- and gen ...200515653123
the generalized transducing salmonella bacteriophage es18: complete genome sequence and dna packaging strategy.the generalized transducing double-stranded dna bacteriophage es18 has an icosahedral head and a long noncontractile tail, and it infects both rough and smooth salmonella enterica strains. we report here the complete 46,900-bp genome nucleotide sequence and provide an analysis of the sequence. its 79 genes and their organization clearly show that es18 is a member of the lambda-like (lambdoid) phage group; however, it contains a novel set of genes that program assembly of the virion head. most of ...200515659686
a novel intranasal protollin-based measles vaccine induces mucosal and systemic neutralizing antibody responses and cell-mediated immunity in mice.protollin-mv is a vaccine produced by mixing split measles virus (mv) antigen with the novel adjuvant protollin (neisseria meningitidis outer membrane proteins non-covalently complexed with shigella flexneri 2a lipopolysaccharide). intranasal immunization of mice with two or three doses of protollin-mv induces both serum igg and mucosal iga with strong neutralizing activity. there is a dose-dependent shift towards lower igg1:igg2a ratios and mv-specific ifngamma production in splenocytes. intran ...200515661386
modulation of an outer membrane protease contributes to the virulence defect of shigella flexneri strains carrying a mutation in the virk locus.the shigella actin assembly protein icsa is removed from the bacterial surface by the protease icsp. we show that decreased intracellular spreading of virk::tn10 mutants is due in part to significant increases in icsp and icsp-mediated cleavage of icsa and that icsp expression is a critical determinant of shigella virulence.200515664968
use of molecular hydrogen as an energy substrate by human pathogenic bacteria.molecular hydrogen is produced as a fermentation by-product in the large intestine of animals and its production can be correlated with the digestibility of the carbohydrates consumed. pathogenic helicobacter species (helicobacter pylori and h. hepaticus) have the ability to use h(2) through a respiratory hydrogenase, and it was demonstrated that the gas is present in the tissues colonized by these pathogens (the stomach and the liver respectively of live animals). mutant strains of h. pylori un ...200515667272
rifaximin--a novel antimicrobial for enteric infections.rifaximin is a poorly absorbed rifamycin antimicrobial drug with in vitro activity against gram-positive, gram-negative and anaerobic bacteria. the minimal concentration that inhibits 90% of strains of bacterial pathogens (mic90) ranges between 32 and 64 microg/ml. less than 1% of the drug is absorbed after oral administration. after three days of therapy, the average fecal level of this drug is 8000 microg/g of stool. selection of resistant mutants, a problem with the related rifampin, appears ...200515667909
sensitive and rapid detection of shigella and enteroinvasive escherichia coli by a loop-mediated isothermal amplification method.here we report a loop-mediated isothermal amplification (lamp) method for detecting shigella and enteroinvasive escherichia coli. the target for this lamp method is the ipah gene which is carried by both of the pathogens. the lamp method efficiently detected the gene within 2 h at a minimal amount of bacteria (8 cfu) per reaction.200515668027
synthesis of two linear padre conjugates bearing a deca- or pentadecasaccharide b epitope as potential synthetic vaccines against shigella flexneri serotype 2a infection.the blockwise synthesis of the 2-aminoethyl glycosides of a deca- and a pentadecasaccharide made of two and three repeating units, respectively, of the shigella flexneri serotype 2a specific polysaccharide is reported. the strategy relies on trifluoromethanesulfonic acid mediated glycosylation of a pentasaccharide building block acting as a glycosyl donor and a potential glycoside acceptor. both targets were made available in amounts large enough for their subsequent conversion into glycoconjuga ...200515669066
analysis of replication region of the cryptic plasmid pag20 from acetobacter aceti 3620.the dna sequence of small cryptic plasmid pag20 in acetobacter aceti was determined at 3064 bp with 51.6% gc pairs. the plasmid encoded a 186 amino acid protein which is important for plasmid replication in gram-negative bacteria except escherichia coli. two 21 bp large direct repeat sequence 1 and two 13 bp direct repeat sequence 2 were determined in the regulation region upstream from gene encoded rep protein. vector pag24 with kanamycin gene and two deletion derivatives pag25 and pag26 withou ...200515670745
physiological stress of intracellular shigella flexneri visualized with a metabolic sensor fused to a surface-reporter system.when deleted of its n-terminal signal-reception domain, the broad host range sigma54-dependent transcriptional regulator xylr, along with its cognate promoter pu, becomes a sensor of the metabolic stress of the carrier bacteria. we have employed a surface reporter system to visualize the physiological status of intracellular shigella flexneri during infection of henle 407 cells in culture. to this end, the xylrdeltaa gene has been engineered adjacent to a bicistronic transcriptional fusion of pu ...200515670852
cloning of a novel gene for quinolone resistance from a transferable plasmid in shigella flexneri 2b.a novel gene for quinolone resistance was cloned from a transferable plasmid carried by a clinical isolate of shigella flexneri 2b that was resistant to fluoroquinolones. the plasmid conferred low-level resistance to quinolones on escherichia coli hb101. the protein encoded by the gene showed 59% amino acid identity with qnr.200515673773
antibiotic resistance in diarrheagenic escherichia coli and shigella strains isolated from children in hanoi, vietnam.the mics for 162 diarrheagenic escherichia coli strains and 28 shigella strains were determined on the basis of nccls guidelines. more than 75% of the strains were resistant to ampicillin, chloramphenicol (53.6% of shigella strains), and trimethoprim-sulfamethoxazole. multiresistance was detected in 89.5% of e. coli strains and 78.6% of shigella strains.200515673777
occurrence of integrons and resistance genes among sulphonamide-resistant shigella spp. from brazil.to determine the occurrence of class 1 and 2 integrons and antimicrobial resistance genes among sulphonamide-resistant shigella strains isolated in brazil during 1999-2003.200515681578
the flag-2 locus, an ancestral gene cluster, is potentially associated with a novel flagellar system from escherichia coli.escherichia coli k-12 possesses two adjacent, divergent, promoterless flagellar genes, fhia-mbha, that are absent from salmonella enterica. through bioinformatics analysis, we found that these genes are remnants of an ancestral 44-gene cluster and are capable of encoding a novel flagellar system, flag-2. in enteroaggregative e. coli strain 042, there is a frameshift in lfgc that is likely to have inactivated the system in this strain. tiling path pcr studies showed that the flag-2 cluster is pre ...200515687208
selection-driven transcriptome polymorphism in escherichia coli/shigella species.to explore the role of transcriptome polymorphism in adaptation of organisms to their environment, we evaluated this parameter for the escherichia coli/shigella bacterial species, which is composed of well-characterized phylogenetic groups that exhibit characteristic life styles ranging from commensalism to intracellular pathogenicity. both the genomic content and the transcriptome of 10 strains representative of the major e. coli/shigella phylogenetic groups were evaluated using macroarrays dis ...200515687289
tyrosine kinase signaling and type iii effectors orchestrating shigella invasion.upon epithelial cell contact, shigella type iii effectors activate complex signaling pathways that induce localized membrane ruffling, resulting in shigella invasion. bacterial induced membrane ruffles require a timely coordination of cytoskeletal processes, including actin polymerization, filament reorganization and depolymerization, orchestrated by rho gtpases and tyrosine kinases. an emerging concept is that multiple shigella effectors act in synergy to promote actin polymerization in membran ...200515694852
actin-based motility of intracellular pathogens.the actin cytoskeleton is harnessed by several pathogenic bacteria that are capable of entering into non-phagocytic cells, the so-called 'invasive bacteria'. among them, a few also exploit the host actin cytoskeleton to move intra- and inter-cellularly. our knowledge of the basic mechanisms underlying actin-based motility has dramatically increased and the list of bacteria that are able to move in this way is also increasing including not only listeria, shigella and rickettsia species but also m ...200515694855
a novel caspase-1/toll-like receptor 4-independent pathway of cell death induced by cytosolic shigella in infected macrophages.shigella-induced macrophage cell death is an important step in the induction of acute inflammatory responses that ultimately lead to bacillary dysentery. cell death was previously reported to be dependent upon the activation of caspase-1 via interaction with ipab secreted by intracellular shigella, but in this study, we show that shigella infection of macrophages can also induce cell death independent of caspase-1 or ipab activity. time-lapse imaging and electron microscopic analyses indicated t ...200515695506
a novel shigella dysenteriae serovar isolated in canada.the etiological agent most commonly associated with bacillary dysentery is shigella. as part of its mandate, the bacteriology and enteric disease program of health canada identifies and serotypes unusual isolates of shigella received from provincial laboratories of public health. in this report, six unusual isolates from three provinces were analyzed biochemically and serologically using slide and tube agglutinations and molecularly using standard pulsed-filed gel electrophoresis (pfge), pcr, an ...200515695673
the nf2 tumor suppressor merlin and the erm proteins interact with n-wasp and regulate its actin polymerization function.the function of the nf2 tumor suppressor merlin has remained elusive despite increasing evidence for its role in actin cytoskeleton reorganization. the closely related erm proteins (ezrin, radixin, and moesin) act as linkers between the cell membrane and cytoskeleton, and have also been implicated as active actin reorganizers. we report here that merlin and the erms can interact with and regulate n-wasp, a critical regulator of actin dynamics. merlin and moesin were found to inhibit n-wasp-media ...200515699051
characterization of the flexible genome complement of the commensal escherichia coli strain a0 34/86 (o83 : k24 : h31).colonization by the commensal escherichia coli strain a0 34/86 (o83 : k24 : h31) has proved to be safe and efficient in the prophylaxis and treatment of nosocomial infections and diarrhoea of preterm and newborn infants in czech paediatric clinics over the past three decades. in searching for traits contributing to this beneficial effect related to the gut colonization capacity of the strain, the authors have analysed its genome by dna-dna hybridization to e. coli k-12 (mg1655) genomic dna array ...200515699189
effects of zinc supplementation as adjunct therapy on the systemic immune responses in shigellosis.zinc is lost during diarrheal diseases, and zinc deficiency induces intestinal morphology-altering inflammatory responses that zinc supplementation can correct.200515699240
spectroscopic characterization of microorganisms by fourier transform infrared microspectroscopy.spectroscopic fingerprints of bacteria were investigated by fourier transform infrared (ftir) microspectroscopy for the elucidation of chemical composition and structural information during growth. good differentiation of six microorganisms was achieved down to the strain level. the inherent compositional and structural differences of cell envelopes and cytoplasm were investigated and utilized to obtain more detailed analysis of the spectroscopic features. bands or regions of key functional grou ...200515700299
role of the pst system in plaque formation by the intracellular pathogen shigella flexneri.in response to the host cell environment, the intracellular pathogen shigella flexneri induces the expression of numerous genes, including those in the pst operon which is predicted to encode a high-affinity phosphate acquisition system that is expressed under reduced phosphate conditions. an s. flexneri pst mutant forms smaller plaques in henle cell monolayers than does the parental strain. this mutant exhibited normal production and localization of the s. flexneri icsa protein. the pst mutant ...200515731038
ipad of shigella flexneri is independently required for regulation of ipa protein secretion and efficient insertion of ipab and ipac into host membranes.shigella flexneri causes human dysentery after invading the cells of the colonic epithelium. the best-studied effectors of shigella entry into colonocytes are the invasion plasmid antigens ipac and ipab. these proteins are exported via a type iii secretion system (ttss) to form a pore in the host membrane that may allow the translocation of other effectors into the host cytoplasm. ttss-mediated secretion of ipad is also required for translocation pore formation, bacterial invasion, and virulence ...200515731041
microbiology. a pathogen attacks while keeping up defense. 200515731433
optimization of virulence functions through glucosylation of shigella lps.shigella, the leading cause of bacillary dysentery, uses a type iii secretion system (ttss) to inject proteins into human cells, leading to bacterial invasion and a vigorous inflammatory response. the bacterium is protected against the response by the o antigen of lipopolysaccharide (lps) on its surface. we show that bacteriophage-encoded glucosylation of shigella o antigen, the basis of different serotypes, shortens the lps molecule by around half. this enhances ttss function without compromisi ...200515731456
recent advances in the development of live, attenuated bacterial vectors.over the last quarter century, scientific advances have created new tools and technologies to improve the safety and efficacy of vaccines. these improvements are spurred by social and commercial needs to enhance existing vaccines or to create new ones against an expanding spectrum of diseases. vaccines based on live, attenuated, pathogenic bacteria were originally developed to prevent infection by homologous pathogens. more recently, strategies have been developed to use these bacterial vaccines ...200515732531
shigella antibiotic resistance in central turkey: comparison of the years 1987-1994 and 1995-2002.the epidemiology and antibiotic susceptibility of shigella species changes over time. updated susceptibility knowledge is necessary for appropriate empirical antibiotic treatment.200515735493
post-infectious irritable bowel syndrome in patients with shigella infection.bacterial gastroenteritis has been known as a risk factor of irritable bowel syndrome (ibs). several risk factors of post-infectious ibs (pi-ibs) have been documented. the aims of this study were to verify the role of bacterial gastroenteritis in the development of ibs and the risk factors for the development of pi-ibs. the clinical course of pi-ibs was also investigated.200515740480
[evaluation of the robobact system for processing stool cultures: another step towards automation in the microbiology laboratory].the objective of this study was to evaluate the robobact system (diesse diagnostica senese s.p.a., italy) for processing stool specimens and to compare it with conventional methodology.200515743574
environmental ph sensing: resolving the vira/virg two-component system inputs for agrobacterium pathogenesis.agrobacterium tumefaciens stands as one of biotechnology's greatest successes, with all plant genetic engineering building on the strategies of this pathogen. by integrating responses to external phs, phenols, and monosaccharides, this organism mobilizes oncogenic elements to efficiently transform most dicotyledonous plants. we now show that the complex signaling network used to regulate lateral gene transfer can be resolved as individual signaling modules. while ph and sugar perception are coup ...200515743967
comparative evaluation of apoptosis induced by shiga toxin 1 and/or lipopolysaccharides in human monocytic and macrophage-like cells.the enteric pathogens shigella dysenteriae serotype 1 and shiga toxin-producing escherichia coli share the property of expressing the structurally and functionally related cytotoxins that comprise the shiga toxin (stx) family. stx-producing bacteria are causative agents of bloody diarrheal diseases that may progress to life threatening complications involving the destruction of blood vessels in the kidneys and the central nervous system (cns). the precise mechanisms of toxin transport across the ...200515748808
establishment of a universal size standard strain for use with the pulsenet standardized pulsed-field gel electrophoresis protocols: converting the national databases to the new size standard.the pulsenet national database, established by the centers for disease control and prevention in 1996, consists of pulsed-field gel electrophoresis (pfge) patterns obtained from isolates of food-borne pathogens (currently escherichia coli o157:h7, salmonella, shigella, and listeria) and textual information about the isolates. electronic images and accompanying text are submitted from over 60 u.s. public health and food regulatory agency laboratories. the pfge patterns are generated according to ...200515750058
molecular epidemiology of shigella flexneri in a long-stay psychiatric nursing center during 2001 to 2003.with six separate wards accommodating more than 1,600 patients, v nursing center (vnc) is a long-stay psychiatric nursing center in eastern taiwan. during 2001 to 2003, 39 shigellosis cases occurred in vnc. different from the notion that most cases of shigellosis are caused by shigella sonnei, all except one of these cases were caused by s. flexneri, with the remaining one caused by an s. sonnei isolate. o-antigen serotyping showed that the 38 s. flexneri strains were of either type 1a (n = 20) ...200515750107
in-vitro antimicrobial activity of lawsonia inermis linn (henna). a pilot study on the omani henna.to investigate the antimicrobial activity of henna's fresh and dry leaves and seeds obtained from oman.200515756356
[serotype and phage type distribution of human salmonella strains isolated in spain, 1997-2001].salmonellosis is one of the most frequent causes of gastroenteritis in spain. serotyping is the gold standard epidemiological marker for subdividing salmonella spp. strains. a small number of serotypes are very frequently isolated, reducing the discriminatory power of serotyping. thus, to increase our knowledge of salmonella spp. epidemiology, additional epidemiological markers, such as phage typing, should be used for this purpose.200515757583
analysis of virulence plasmid gene expression defines three classes of effectors in the type iii secretion system of shigella flexneri.proteins directly involved in entry and dissemination of shigella flexneri into epithelial cells are encoded by a virulence plasmid of 200 kb. a 30-kb region (designated the entry region) of this plasmid encodes components of a type iii secretion (tts) apparatus, substrates of this apparatus and their dedicated chaperones. during growth of bacteria in broth, expression of these genes is induced at 37 degrees c and the tts apparatus is assembled in the bacterial envelope but is not active. secret ...200515758240
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