Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| efficacy of solar disinfection of escherichia coli, shigella flexneri, salmonella typhimurium and vibrio cholerae. | to determine the efficacy of solar disinfection (sodis) for enteric pathogens and to test applicability of the reciprocity law. | 2006 | 16968294 |
| quinine sulfate inhibits invasion of salmonella typhimurium and shigella flexneri: a preliminary study. | 2006 | 16987134 | |
| ospf and ospc1 are shigella flexneri type iii secretion system effectors that are required for postinvasion aspects of virulence. | shigella flexneri is the causative agent of dysentery, and its pathogenesis is mediated by a type iii secretion system (t3ss). s. flexneri secretes effector proteins into the eukaryotic cell via the t3ss, and these proteins usurp host cellular functions to the benefit of the bacteria. ospf and ospc1 are known to be secreted by s. flexneri, but their functions are unknown. we transformed s. flexneri with a plasmid that expresses a two-hemagglutinin tag (2ha) in frame with ospf or ospc1 and verifi ... | 2006 | 16988276 |
| crystal structure of the diadenosine tetraphosphate hydrolase from shigella flexneri 2a. | 2006 | 17006950 | |
| induction of expression of hfq by dksa is essential for shigella flexneri virulence. | hfq plays an important role in cellular physiology by regulating the expression of several genes. hfq synthesis in escherichia coli is subject to auto-repression at translational level. studies with shigella flexneri show that hfq transcription is regulated by a pleiotropic regulator, dksa. comparison of gene expression profiles of wild type and dksa mutant s. flexneri determined that hfq expression was reduced in the dksa mutant. as dksa is required for stress resistance and plaque formation in ... | 2006 | 17020583 |
| development of a serotype-specific dna microarray for identification of some shigella and pathogenic escherichia coli strains. | shigella and pathogenic escherichia coli are major causes of human infectious diseases and are responsible for millions of cases of diarrhea worldwide every year. a convenient and rapid method to identify highly pathogenic serotypes of shigella and e. coli is needed for large-scale epidemiologic study, timely clinical diagnosis, and reliable quarantine of the pathogens. in this study, a dna microarray targeting o-serotype-specific genes was developed to detect 15 serotypes of shigella and e. col ... | 2006 | 17021058 |
| [the electron microscopic study of cell-to-cell interactions between antagonistic microorganisms]. | the electron microscopic study of thin sections and positively stained specimens of cells taken from particular cocultures of lactobacillus acidophilus d75, lactobacillus casei yit 9018, shigella flexnery 2a, bacillus subtilis atcc 6633, and staphylococcus aureus atcc 25923 (some of these bacteria are antagonistic to others) showed the presence of specific ultrastructural elements indicating cell specialization and cooperation. the responses of antagonistic bacteria manifested themselves at the ... | 2006 | 17025183 |
| direct detection of bacterial faecal indicators in water samples using pcr. | the presence of enteric pathogens in water resources represents a serious risk for public health. therefore, their precise detection, and especially detection of e. coli, which is obviously regarded as the main indicator of faecal contamination of water, is an essential step in ensuring bacterial safety of water. numerous pcr protocols for detection of e. coli have been published to date. they are usually based on amplification of regions derived from lacz (beta-d-galactosidase) and uida (beta-d ... | 2006 | 17037144 |
| [rapid detection of pseudomonas aeruginosa by the fluorescence quantitative pcr assay targeting 16s rdna]. | the 16s rdna specific primers were designed for rapid detection of pseudomonas aeruginosa (pa) by the fluorescence quantitative pcr (fq-pcr) assay, based upon multiple sequence alignment and phylogenetic tree analysis of the 16s rdnas of over 20 bacteria. after extraction of pa genomic dna, the target 16s rdna fragment was amplified by pcr with specific primers, and used to construct recombinant pmdt-pfr plasmid, the dilution gradients of which were subjected to the standard quantitation curve i ... | 2006 | 17037203 |
| distribution of shigella enterotoxin genes and secreted autotransporter toxin gene among diverse species and serotypes of shigella isolated from andaman islands, india. | we studied the prevalence and distribution of the newly described genes for shigella enterotoxins (shet1 and shet2, encoded by set and sen genes) and secreted auto-transporter toxin (encoded by sat gene) in clinical isolates from the andaman islands, india. a total of 153 shigella isolates obtained from hospitalized patients during 1994-2004 were analysed. these isolates included all the four species of shigella (s. dyseteriae-29, s. flexneri-75, s. sonnei-38, s. boydii-5) that belonged to diver ... | 2006 | 17054749 |
| transcriptional slippage controls production of type iii secretion apparatus components in shigella flexneri. | during transcription, series of approximately 9 as or ts can direct rna polymerase to incorporate into the mrna nucleotides not encoded by the dna, changing the reading frame downstream from the slippage site. we detected series of 9 or 10 as in spa13, spa33 and mxia encoding type iii secretion apparatus components. analysis of cdnas indicated that transcriptional slippage occurs in spa13, mxia and spa33. changes in the reading frame were confirmed by using plasmids carrying slippage sites in th ... | 2006 | 17059566 |
| identification of essential loops and residues of glucosyltransferase v (gtrv) of shigella flexneri. | lipopolysaccharide (lps), particularly the o-antigen component, is one of many virulence determinants necessary for shigella flexneri pathogenesis. o-antigen modification is mediated by glucosyltransferase (gtr) genes encoded by temperate serotype-converting bacteriophages. the gtrv and gtrx genes encode the gtrv and gtrx glucosyltransferases, respectively. these are integral membrane proteins, which catalyze the transfer of a glucosyl residue via an alpha1,3 linkage to rhamnose ii and rhamnose ... | 2006 | 17060158 |
| ipaa targets beta1 integrins and rho to promote actin cytoskeleton rearrangements necessary for shigella entry. | shigella invasion into the colonic epithelium involves many steps including the formation of large membrane protrusions by the epithelial cells that facilitate bacterial engulfment. ipaa, a shigella protein secreted into target cells upon cell contact induces a loss of actin stress fibers in cells and promotes the reorganization of actin at the site of entry. the mechanism for this is not known but is thought to involve recruitment of the focal adhesion protein vinculin to ipaa. here we have exa ... | 2006 | 17060328 |
| effects of the bacteriocin psvp-10 produced by pseudomonas sp. on sensitive bacterial strains. | the bacteriocin psvp-10 is a 2.6 kda peptide which was isolated and purified from pseudomonas sp. this bacteriocin possesses lethal activity over enterococcus faecalis, salmonella typhimurium and shigella flexneri. the experimental assays showed that the bacteriocin is able to be adsorbed by all cells of these bacterial species and also by their isolated cell walls. it was observed that the resistant mutants and their respective cell walls are unable to adsorb the bacteriocin. assays performed w ... | 2002 | 17061511 |
| shigella flexneri strains produce bacteriocins active against members of the human microbial intestinal flora. | the principal aim of this work was to detect the bacteriocinogenic capacity of s. flexneri strains on members of the human intestinal flora. a total of 49 bacteriocinogenic s. flexneri strains were isolated from individuals of both sexes and different ages. the bacteriocins were detected by means of the drop method using e. coli and b. fragilis as target strains. the serotypes of the s. flexneri were determined. the producer capacity of bacteriocins was analysed in 10 different colonies of the s ... | 2004 | 17061528 |
| determination of the profile of fatty acids of 4 species of shigella spp by chromatography of gases. | shigella boydii, shigella flexneri, shigella dysenteriae and shigella sonnei were identified using gas chromatography instead of the traditional techniques. their acid methyl esters profiles were determined using a gas chromatograph hewlett packard 5890a and a rsl-150 heliflex capillary column. a total of 192 samples were analyzed both reference strains (atcc 8700, indre b2188, b2194 and b2199) and environmental isolates. 12 fatty acids were included in the profiles from which 3-hydroxytetradeca ... | 2002 | 17063774 |
| enterobacterial 38-kda outer membrane protein is an age-dependent molecular marker of innate immunity and immunoglobulin deficiency as results from its reactivity with igg and iga antibody. | in earlier studies on an animal model we observed protective properties of outer membrane proteins (omps) of shigella, hafnia, and escherichia coli strains. in order to investigate human sera for reactivity with omps we subjected these proteins to immunoblotting with umbilical cord plasma and sera from children and adults. the igg and iga antibodies interacted primarily with a 38-kda protein, in similar way for several enterobacterial strains, but different for pseudomonas aeruginosa. this obser ... | 2006 | 17064276 |
| prevalence and antimicrobial susceptibility patterns of shigella species in asmara, eritrea, northeast africa. | diarrheal diseases are an important cause of morbidity and mortality in children in developing countries. of the bacterial causes of dysentery, shigella are the major enteropathogens with outbreak potential and common development of antimicrobial resistance. this study determined the prevalence and antimicrobial susceptibility patterns of different spp. of shigella in asmara, eritrea. | 2006 | 17066201 |
| immunoproteome analysis of soluble and membrane proteins of shigella flexneri 2457t. | to profile the immunogenic proteins of shigella flexneri (s. flexneri) expressed during human infection using a proteomic approach. | 2006 | 17075984 |
| self-chaperoning of the type iii secretion system needle tip proteins ipad and bipd. | bacteria expressing type iii secretion systems (t3ss) have been responsible for the deaths of millions worldwide, acting as key virulence elements in diseases ranging from plague to typhoid fever. the t3ss is composed of a basal body, which traverses both bacterial membranes, and an external needle through which effector proteins are secreted. we report multiple crystal structures of two proteins that sit at the tip of the needle and are essential for virulence: ipad from shigella flexneri and b ... | 2007 | 17077085 |
| octaplex pcr and fluorescence-based capillary electrophoresis for identification of human diarrheagenic escherichia coli and shigella spp. | a multiplex pcr assay, amplifying seven specific virulence genes and one internal control gene in a single reaction, was developed to identify the five main pathotypes of diarrheagenic escherichia coli and shigella spp. the virulence genes selected for each category were stx1, stx2, and eaea for enterohemorrhagic e. coli (ehec), eaea for enteropathogenic e. coli (epec), stib and lti for enterotoxigenic e. coli (etec), ipah for enteroinvasive e. coli (eiec) and shigella spp., and aggr for enteroa ... | 2007 | 17079041 |
| o-acetylation in the o-specific polysaccharide isolated from shigella flexneri serotype 2a. | shigella flexneri causes diarrheal diseases especially in infants and children in developing countries. modifications of the lipopolysaccharide (lps) molecule, like bacteriophage-mediated glucosylation and acetylation of the o-specific chain (o-sp), are important for the lps antigenicity and consequently for the immunogenicity of the polysaccharide-based vaccines against shigellosis. here, we report the degree of o-acetylation and the localisation of o-acetyl groups and side-chain glucose substi ... | 2007 | 17087926 |
| shigella applies molecular mimicry to subvert vinculin and invade host cells. | shigella flexneri, the causative agent of bacillary dysentery, injects invasin proteins through a type iii secretion apparatus upon contacting the host cell, which triggers pathogen internalization. the invasin ipaa is essential for s. flexneri pathogenesis and binds to the cytoskeletal protein vinculin to facilitate host cell entry. we report that ipaa harbors two vinculin-binding sites (vbss) within its c-terminal domain that bind to and activate vinculin in a mutually exclusive fashion. only ... | 2006 | 17088427 |
| microtubule-severing activity of shigella is pivotal for intercellular spreading. | some pathogenic bacteria actually invade the cytoplasm of their target host cells. invasive bacteria acquire the propulsive force to move by recruiting actin and inducing its polymerization. here we show that shigella movement within the cytoplasm was severely hindered by microtubules and that the bacteria destroyed surrounding microtubules by secreting vira by means of the type iii secretion system. degradation of microtubules by vira was dependent on its alpha-tubulin-specific cysteine proteas ... | 2006 | 17095701 |
| genetic characterization of multidrug resistance in shigella spp. from japan. | this study characterized the genetic basis of antimicrobial resistance of a number of shigella spp. isolated from humans from 2000 to 2004 in hiroshima prefecture, japan. a total of 26 isolates of shigella spp. were included in this study. antimicrobial susceptibility tests revealed high levels of resistance, especially to ampicillin, streptomycin, trimethoprim, tetracycline, nalidixic acid and ciprofloxacin. pcr and dna sequencing were used for screening and characterization of antibiotic-resis ... | 2006 | 17108272 |
| ipad is localized at the tip of the shigella flexneri type iii secretion apparatus. | type iii secretion (t3s) systems are used by numerous gram-negative pathogenic bacteria to inject virulence proteins into animal and plant host cells. the core of the t3s apparatus, known as the needle complex, is composed of a basal body transversing both bacterial membranes and a needle protruding above the bacterial surface. in shigella flexneri, ipad is required to inhibit the activity of the t3s apparatus prior to contact of bacteria with host and has been proposed to assist translocation o ... | 2007 | 17110044 |
| enteropathogenic escherichia coli, shigella flexneri, and listeria monocytogenes recruit a junctional protein, zonula occludens-1, to actin tails and pedestals. | enteropathogenic escherichia coli, shigella flexneri, and listeria monocytogenes induce localized actin polymerization at the cytoplasmic face of the plasma membrane or within the host cytoplasm, creating unique actin-rich structures termed pedestals or actin tails. the process is known to be mediated by the actin-related protein 2 and 3 (arp2/3) complex, which in these cases acts downstream of neural wiskott-aldrich syndrome protein (n-wasp) or of a listerial functional homolog of wasp family p ... | 2007 | 17118974 |
| a new monoterpene glycoside and antibacterial monoterpene glycosides from paeonia suffruticosa. | antibacterial activity-guided fractionation of the chci3-meoh (1:1) extract of paeonia suffruticosa root bark furnished three monoterpene glycosides, 6-o-vanillyoxypaeoniflorin (1), mudanpioside-h (2), and galloyl-oxypaeoniflorin (3). of the isolated compounds, compound 1 is a new compound. all isolated compounds showed broad, but moderate, antibacterial activity with minimum inhibitory concentration (mic) values in the range of 100 to 500 microg/ml against eighteen pathogenic microorganisms of ... | 2006 | 17121173 |
| salmonella and shigella in freshly squeezed orange juice, fresh oranges, and wiping cloths collected from public markets and street booths in guadalajara, mexico: incidence and comparison of analytical routes. | a survey of the presence of salmonella and shigella in freshly squeezed orange juice and related samples was conducted in guadalajara, mexico. one hundred samples of freshly squeezed orange juice were collected from 49 street booths and 51 small food service establishments. in addition, 75 fresh orange samples, each consisting of five orange units, and 75 wiping cloths were collected from the same establishments from which juice had been collected. salmonella was isolated from 14, 20, and 23% of ... | 2006 | 17133801 |
| an injected bacterial effector targets chromatin access for transcription factor nf-kappab to alter transcription of host genes involved in immune responses. | phosphorylation of histone h3 at ser10 increases chromatin accessibility to transcription factor nf-kappab on a subset of genes involved in immune responses. here we report that a bacterial pathogen abrogated phosphorylation of histone h3 to 'shape' the transcriptional responses of infected host cells. we identify the shigella flexneri protein effector ospf as a dually specific phosphatase that dephosphorylated mitogen-activated protein kinases in the nucleus, thus preventing histone h3 phosphor ... | 2007 | 17159983 |
| shigella ipgb1 promotes bacterial entry through the elmo-dock180 machinery. | shigella use a special mechanism to invade epithelial cells called 'the trigger mechanism of entry', which allows epithelial cells to trap several bacteria simultaneously. on contact, shigella deliver effectors into epithelial cells through the type iii secretion system. here, we show that one of the effectors, ipgb1, has a pivotal role in producing membrane ruffles by exploiting the rhog-elmo-dock180 pathway to stimulate rac1 activity. using pulldown assays, we identified engulfment and cell mo ... | 2007 | 17173036 |
| vaccine potential for inactivated shigellae. | we used human monocyte-derived dendritic cells (dc) and balb/c mice as models to establish the immunogenic and protective potential of formalin-inactivated shigella spp. incubation of dc with inactivated or live bacteria induced dc maturation and cytokine release. mice immunized orally or intranasally with killed s. flexneri, s. sonnei, or s. dysenteriae developed igg and fecal iga titers to the homologous lps. following respiratory challenge with the live homologous organisms, 80-100% survival ... | 2007 | 17178431 |
| villin severing activity enhances actin-based motility in vivo. | villin, an actin-binding protein associated with the actin bundles that support microvilli, bundles, caps, nucleates, and severs actin in a calcium-dependant manner in vitro. we hypothesized that the severing activity of villin is responsible for its reported role in enhancing cell plasticity and motility. to test this hypothesis, we chose a loss of function strategy and introduced mutations in villin based on sequence comparison with capg. by pyrene-actin assays, we demonstrate that this mutant ... | 2007 | 17182858 |
| use of linear, weibull, and log-logistic functions to model pressure inactivation of seven foodborne pathogens in milk. | survival curves of six foodborne pathogens suspended in ultra high-temperature (uht) whole milk and exposed to high hydrostatic pressure at 21.5 degrees c were obtained. vibrio parahaemolyticus was treated at 300 mpa and other pathogens, listeria monocytogenes, escherichia coli o157:h7, salmonella enterica serovar enteritidis, salmonella enterica serovar typhimurium, and staphylococcus aureus were treated at 600 mpa. all the survival curves showed a rapid initial drop in bacterial counts followe ... | 2007 | 17188197 |
| polar positional information in escherichia coli spherical cells. | shigella surface protein icsa and its cytoplasmic derivatives are localized to the old pole of rod-shaped cells when expressed in escherichia coli. in spherical mreb cells, icsa is targeted to ectopic sites and close to one extremity of actin-like mamk filament. to gain insight into the properties of the sites containing polar material, we studied the icsa localization in spherical cells. gfp was exported into the periplasm via the tat pathway and used as a periplasmic space marker. gfp displaye ... | 2007 | 17188233 |
| [time course changes in cytokines content and gas composition in blood of patients with salmonellosis and acute shigellosis]. | to study changes in serum concentrations of interleukines (il) and tumor necrosis factor alpha (tnfa) in the course of acute moderate and severe shigellosis and salmonellosis; to elicit their correlation with disorders of gas and electrolyte blood composition and acid-base balance (abb). | 2006 | 17195521 |
| shigella chromosomal ipah proteins are secreted via the type iii secretion system and act as effectors. | shigella possess 220 kb plasmid, and the major virulence determinants, called effectors, and the type iii secretion system (ttss) are exclusively encoded by the plasmid. the genome sequences of s. flexneri strains indicate that several ipah family genes are located on both the plasmid and the chromosome, but whether their chromosomal ipah cognates can be secreted from shigella remains unknown. here we report that s. flexneri strain, ysh6000 encodes seven ipah cognate genes on the chromosome and ... | 2007 | 17214743 |
| [detection of class i integron and its relation to antimicrobial resistance of shigella flexneri in children]. | to investigate class i integron of shigella flexneri, its prevalence in children, and its relation to bacterial resistance to antimicrobial agents. | 2006 | 17217663 |
| an h-ns-like stealth protein aids horizontal dna transmission in bacteria. | the sfh protein is encoded by self-transmissible plasmids involved in human typhoid and is closely related to the global regulator h-ns. we have found that sfh provides a stealth function that allows the plasmids to be transmitted to new bacterial hosts with minimal effects on their fitness. introducing the plasmid without the sfh gene imposes a mild h-ns(-) phenotype and a severe loss of fitness due to titration of the cellular pool of h-ns by the a+t-rich plasmid. this stealth strategy seems t ... | 2007 | 17218529 |
| erosion of interaction networks in reduced and degraded genomes. | unlike eukaryotes, which often recruit duplicated genes into existing protein-protein interaction (ppi) networks, the low levels of gene duplication coupled with the high probability of lateral transfer of novel genes alters the manner in which ppi networks can evolve in bacteria. by inferring the ppis present in the ancestor to contemporary gammaproteobacteria, we were able to trace the changes in gene repertoires, and their consequences on ppi network evolution, in several bacterial lineages t ... | 2007 | 17219366 |
| immunogenicity and characterization of wrsf2g11: a second generation live attenuated shigella flexneri 2a vaccine strain. | recent clinical trials involving live attenuated shigella vaccine strains sc602 and wrss1 have revealed that deletion of the virg(icsa) gene dramatically reduces virulence in human volunteers. these strains can be given at low oral doses and induce a strong, and in some cases, protective immune responses. however, residual vaccine associated reactogenicity suggests that further attenuation is required. a recent clinical trial indicated that the set and sen enterotoxin genes contribute to the sym ... | 2007 | 17229494 |
| in-vitro antibacterial, antifungal and cytotoxic properties of metal-based furanyl derived sulfonamides. | a new series of antibacterial and antifungal furanyl-derived sulfonamides and their cobalt (ii), copper (ii), nickel (ii) and zinc (ii) metal complexes have been synthesized, characterized and screened for their in-vitro antibacterial activity against four gram-negative (escherichia coli, shigella flexneri, pseudomonas aeruginosa and salmonella typhi) and two gram-positive (bacillus subtilis and staphylococcus aureus) bacterial strains and, for in-vitro antifungal activity against trichophyton l ... | 2006 | 17252952 |
| extended-spectrum beta-lactamase-producing shigella strains in israel, 2000-2004. | routine susceptibility testing of 5,616 shigella isolates at the national shigella reference centre in israel over a 5-year period (2000-2004) revealed resistance to ceftriaxone in one strain of shigella boydii 2 and in two strains each of shigella flexneri 2a, s. flexneri 6, and shigella sonnei. all seven isolates were confirmed as producers of extended-spectrum beta-lactamase (esbl) by the combination disk method, the vitek 1 system, and a modification of the double-disk synergy test, which is ... | 2007 | 17265070 |
| epidemiological characterization of resistance and pcr typing of shigella flexneri and shigella sonnei strains isolated from bacillary dysentery cases in southeast brazil. | shigella spp are gram-negative, anaerobic facultative, non-motile, and non-sporulated bacilli of the enterobacteriaceae family responsible for "shigellosis" or bacillary dysentery, an important cause of worldwide morbidity and mortality. however, despite this, there are very few epidemiological studies about this bacterium in brazil. we studied the antibiotic resistance profiles and the clonal structure of 60 shigella strains (30 s. flexneri and 30 s. sonnei) isolated from shigellosis cases in d ... | 2007 | 17273662 |
| new animal model of shigellosis in the guinea pig: its usefulness for protective efficacy studies. | it has been difficult to evaluate the protective efficacy of vaccine candidates against shigellosis, a major form of bacillary dysentery caused by shigella spp. infection, because of the lack of suitable animal models. to develop a proper animal model representing human bacillary dysentery, guinea pigs were challenged with virulent shigella flexneri serotype 2a (strains 2457t or ysh6000) or s. flexneri 5a (strain m90t) by the intrarectal (i.r.) route. interestingly, all guinea pigs administered ... | 2007 | 17277155 |
| gene expression profiling of the ph response in shigella flexneri 2a. | the ph response of shigella flexneri 2a 301 was identified by gene expression profiling. gene expression profiles of cells grown in ph 4.5 or 8.6 were compared with the profiles of cells grown at ph 7.0. differential expression was observed for 307 genes: 97 were acid up-regulated, 102 were acid down-regulated, 91 were base up-regulated, and 86 were base down-regulated. twenty-seven genes were found to be both acid and base up-regulated, and 29 genes were both acid and base down-regulated. this ... | 2007 | 17286558 |
| o-specific [corrected] polysaccharide conjugate vaccine-induced [corrected] antibodies prevent invasion of shigella into caco-2 cells and may be curative. | the o-specific polysaccharide (o-sp) domain of shigella lps is both an essential virulence factor and a protective antigen for this genus. a critical level of serum igg anti-o-sp was shown to confer immunity to shigellosis, likely by complement-mediated bacteriolysis of the inoculum. conjugate shigella o-sp vaccines were shown to be safe and immunogenic in children, and, in a preliminary study, shigella sonnei vaccine was protective in young adults. characteristic of shigellosis is bacterial inv ... | 2007 | 17287349 |
| capping of actin filaments by vinculin activated by the shigella ipaa carboxyl-terminal domain. | shigella, the causative agent of bacillary dysentery, invades epithelial cells. upon bacterial-cell contact, the type iii bacterial effector ipaa binds to the cytoskeletal protein vinculin to promote actin reorganization required for efficient bacterial uptake. we show that the last 74 c-terminal residues of ipaa (a559) bind to human vinculin (hv) and promotes its association with actin filaments. polymerisation experiments demonstrated that a559 was sufficient to induce hv-dependent partial cap ... | 2007 | 17289036 |
| bile salts stimulate recruitment of ipab to the shigella flexneri surface, where it colocalizes with ipad at the tip of the type iii secretion needle. | shigella flexneri uses its type iii secretion apparatus (ttsa) to deliver invasins into human cells. this ttsa possesses an external needle with ipad at its tip. we now show that deoxycholate promotes the stable recruitment of ipab to the needle tip without inducing a rapid burst of type iii secretion. the maintenance of ipab at the needle tip requires a stable association of ipad with the shigella surface. this is the first demonstration of a translocator protein being stably associated with th ... | 2007 | 17296762 |
| the phosphothreonine lyase activity of a bacterial type iii effector family. | pathogenic bacteria use the type iii secretion system to deliver effector proteins into host cells to modulate the host signaling pathways. in this study, the shigella type iii effector ospf was shown to inactivate mitogen-activated protein kinases (mapks) [extracellular signal-regulated kinases 1 and 2 (erk1/2), c-jun n-terminal kinase, and p38]. ospf irreversibly removed phosphate groups from the phosphothreonine but not from the phosphotyrosine residue in the activation loop of mapks. mass sp ... | 2007 | 17303758 |
| yeast functional genomic screens lead to identification of a role for a bacterial effector in innate immunity regulation. | numerous bacterial pathogens manipulate host cell processes to promote infection and ultimately cause disease through the action of proteins that they directly inject into host cells. identification of the targets and molecular mechanisms of action used by these bacterial effector proteins is critical to understanding pathogenesis. we have developed a systems biological approach using the yeast saccharomyces cerevisiae that can expedite the identification of cellular processes targeted by bacter ... | 2007 | 17305427 |
| the role of the vacb gene in the pathogenesis of brucella abortus. | brucella species are important zoonotic pathogens affecting a wide variety of mammals. therefore, the identification of new brucella virulence factors is of great interest in understanding bacterial pathogenesis and immune evasion. in this study, we have identified brucella abortus vacb gene that presents 2343 nucleotides and 781 amino acids and it shows 39% identity with shigella flexneri vacb gene that encodes an exoribonuclease rnase r involved in bacterial virulence. further, we have inactiv ... | 2007 | 17306588 |
| h-ns antagonism in shigella flexneri by virb, a virulence gene transcription regulator that is closely related to plasmid partition factors. | the virb protein of shigella flexneri is a positive regulator of the major virulence operons of this enteroinvasive intracellular pathogen. virb resembles no other transcription factor but is strongly homologous to plasmid partition proteins. we found that the binding of the virb protein to the promoter region of the icsb virulence gene induced hypersensitivity to cleavage by dnase i over a region to which the h-ns repressor protein binds and completely abolished the protection of this sequence ... | 2007 | 17307842 |
| conformational stability and differential structural analysis of lcrv, pcrv, bipd, and sipd from type iii secretion systems. | diverse gram-negative bacteria use type iii secretion systems (t3ss) to translocate effector proteins into the cytoplasm of eukaryotic cells. the type iii secretion apparatus (t3sa) consists of a basal body spanning both bacterial membranes and an external needle. a sensor protein lies at the needle tip to detect environmental signals that trigger type iii secretion. the shigella flexneri t3sa needle tip protein, invasion plasmid antigen d (ipad), possesses two independently folding domains in v ... | 2007 | 17327391 |
| expression level of heterologous tat genes is crucial for in vivo reconstitution of a functional tat translocase in escherichia coli. | the tat system has the remarkable capacity of exporting proteins in folded conformation across the cytoplasmic membrane. the functional tat translocase from gram-negative bacteria consists of tata, tatb and tatc proteins. to gain information about the species specificity of the tat translocase, we cloned tat genes from gram-negative pathogens shigella flexneri 2a str. 301, vibrio cholerae el tor n16961, pseudomonas aeruginosa pao1, thermophilic sulfolobus solfataricus p2, thermus thermophilus hb ... | 2007 | 17336443 |
| shigella flexneri inhibits staurosporine-induced apoptosis in epithelial cells. | shigella flexneri is a facultative intracellular organism that causes bacillary dysentery. the shigella ipab protein activates caspase 1 in macrophages, which eventually leads to apoptosis. in contrast, epithelial cells infected with shigella undergo a stress response but do not die. therefore, the objective of this study was to determine if shigella has the ability to inhibit apoptosis in epithelial cells. a modified gentamicin protection assay was used to investigate if hela cells infected wit ... | 2007 | 17339354 |
| [shigella flexneri modulates host cell epigenetic information as a strategy to shape the transcriptional response]. | 2007 | 17349276 | |
| the type iii secretion system needle tip complex mediates host cell sensing and translocon insertion. | type iii secretion systems (t3sss) are essential virulence determinants of many gram-negative bacterial pathogens. the shigella t3ss consists of a cytoplasmic bulb, a transmembrane region and a hollow 'needle' protruding from the bacterial surface. physical contact with host cells initiates secretion and leads to assembly of a pore, formed by ipab and ipac, in the host cell membrane, through which proteins that facilitate host cell invasion are translocated. as the needle is implicated in host c ... | 2007 | 17367391 |
| inactivation of foodborne pathogens using a one atmosphere uniform glow discharge plasma. | this study was conducted to determine the efficacy of a one atmosphere uniform glow discharge plasma (oaugdp) for inactivation of foodborne pathogens and to evaluate the influence of growth temperature, ph, and culture age on their inactivation. escherichia coli o157:h7, listeria monocytogenes, staphylococcus aureus, bacillus cereus, salmonella enteritidis, vibrio parahaemolyticus, yersinia enterocolitica, and shigella flexneri were evaluated. three-strain mixtures of each bacterium were inocula ... | 2007 | 17378708 |
| small rnas controlling iron metabolism. | iron is one of the most important metals in the metabolism of many organisms, including bacteria, in which it serves as a cofactor in multiple enzymatic reactions. most of the earlier research on iron regulation in bacteria has focused on the transcriptional regulator fur and its effect on the many genes involved in iron uptake. more recent work demonstrates the essential role of a small regulatory rna, ryhb, in iron metabolism. ryhb downregulates a large number of transcripts encoding iron-usin ... | 2007 | 17383226 |
| assessment and interpretation of bacterial viability by using the live/dead baclight kit in combination with flow cytometry. | the commercially available live/dead baclight kit is enjoying increased popularity among researchers in various fields of microbiology. its use in combination with flow cytometry brought up new questions about how to interpret live/dead staining results. intermediate states, normally difficult to detect with epifluorescence microscopy, are a common phenomenon when the assay is used in flow cytometry and still lack rationale. it is shown here that the application of propidium iodide in combinatio ... | 2007 | 17384309 |
| a new antibacterial compound produced by an indigenous marine bacteria--fermentation, isolation, and biological activity. | the use of microorganisms for biological purpose has become an effective alternative to control pathogens. a marine bacterium pseudomonas aeruginosa was isolated from eal fish of baluchistan coast of pakistan. this strain produced a bactericidal antibiotic against environmental and clinical isolates. in this study, we purified bactericidal antibiotic from the ethyl acetate extract of the cells of p. aeruginosa and analyzed its chemical structure. based on spectrometric analysis, this compound 1 ... | 2006 | 17393659 |
| altered expression of muc2 and muc5ac in response to shigella infection, an in vivo study. | infection of mucosal epithelial cells by shigella species leads to an intense and acute inflammatory bowel disease that is characterized by watery diarrhea and purulent discharge. mucin production is a common defense mechanism to protect the underlying mucosa against pathogens. the molecular mechanism(s) underlying mucin induction is unknown in shigellosis. in this study, we have evaluated the relationship between shigella infection, the expression of muc2 and muc5ac and the participation of sig ... | 2007 | 17395379 |
| shigella flexneri type 2 infection in captive nonhuman primates. | 1985 | 17422604 | |
| dipstick for rapid diagnosis of shigella flexneri 2a in stool. | shigellosis or bacillary dysentery, an acute bloody diarrhoea, is a major public health burden in developing countries. in the absence of prompt and appropriate treatment, the infection is often fatal, particularly in young malnourished children. here, we describe a new diagnostic test for rapid detection, in stool, at the bedside of patients, of shigella flexneri 2a, the most predominant agent of the endemic form of the disease. | 2007 | 17440606 |
| effect of intensive handwashing in the prevention of diarrhoeal illness among patients with aids: a randomized controlled study. | patients with aids frequently develop diarrhoeal illness. in this randomized, controlled study, 260 patients were screened for those who had not had diarrhoea in the preceding 3 months and who had received a stable highly active antiretroviral therapy regimen for at least 6 weeks prior to the study enrollment. a total of 148 patients met the inclusion criteria and were enrolled: 75 patients were randomly assigned to an intensive handwashing intervention (i.e. handwashing after defecation, after ... | 2007 | 17446290 |
| tumor-specific colonization, tissue distribution, and gene induction by probiotic escherichia coli nissle 1917 in live mice. | systemic administration of microorganisms into tumor-bearing mice revealed preferential accumulation in tumors in comparison to clearance in organs such as spleen and liver. here we compared the efficiency of tumor-specific colonization of pathogenic salmonella typhimurium strains 14028 and sl1344 to the enteroinvasive escherichia coli 4608-58 strain and to the attenuated salmonella flexneri 2a sc602 strain, as well as to the uropathogenic e. coli cft073, the non-pathogenic e. coli top10, and th ... | 2007 | 17448724 |
| [pfge of shigella flexneri 4c isolates from food-poisoning outbreaks and sporadic diarrhea patients]. | to know the molecular characteristic of shigella flexneri 4c isolates from patients in two food-poisoning outbreaks and one sporadic diarrhea case in hangzhou, china. | 2007 | 17484212 |
| [pathogens trapped in neutrophils nets]. | 2007 | 17502056 | |
| immunogenicity and protective efficacy offered by a ribosomal-based vaccine from shigella flexneri 2a. | shigellosis is a major form of bacillary dysentery caused by shigella infection. shigella ribosome-based vaccines (srv), considered among the potent vaccine candidates, are composed of o-antigen and ribosome isolated from s. flexneri 2a. to investigate the immunogenicity and protective efficacy of srv, mice were vaccinated with srv via the intranasal (i.n.) route. interestingly, robust levels of shigella-derived lps-specific igg and iga abs and antibody-forming cells were elicited in systemic an ... | 2007 | 17507120 |
| epidemiology and evolution of genotype and antimicrobial resistance of an imported shigella sonnei clone circulating in central taiwan. | shigella sonnei replaced shigella flexneri to become the predominant species for shigellosis in 2001 to 2003 in central taiwan. a total of 425 s. sonnei isolates collected from 1996 to 2004 were available for characterization by pulsed-field gel electrophoresis (pfge), inter-is1 spacer typing (ist), and antimicrobial susceptibility testing. the results showed that at least 21 ist clones had emerged for the s. sonnei infections in 1996 to 2004. most ist clones lasted for a short time; some circul ... | 2007 | 17509797 |
| rapid engineering of bacterial reporter gene fusions by using red recombination. | reporter gene fusions are essential tools for the investigation of gene regulation. such fusions are traditionally generated by transposon mutagenesis and identified by a suitable selection procedure. alternatively, specific reporter fusions can be generated by cloning of dna fragments containing promoters or other regulatory elements in reporter plasmids. here, we describe a novel approach for the rapid generation of reporter gene fusions in single copies at defined positions in bacterial genom ... | 2007 | 17513596 |
| [mathematical modeling and prognosis of incidence of enteric anthroponoses with aqueous route of transmission]. | using data on long-term dynamics of epidemic process of acute enteric infections enteric with aqueous route of transmission (typhoid fever, shigellosis caused by shigella flexneri, hepatitis a, rotavirus gastroenteritis, etc.)the equation of regression was developed with the help of chebyshev's polynoms. predicted incidences of these infections for 2005 were on 61.2-99.5% in agree with the real ones on two territories of north region of west siberia. predicted incidence for 2006 is reflecting te ... | 2007 | 17523473 |
| icsa surface presentation in shigella flexneri requires the periplasmic chaperones degp, skp, and sura. | a shigella flexneri degp mutant, which was defective for plaque formation in henle cell monolayers, had a reduced amount of icsa detectable on the bacterial surface with antibody. however, the mutant secreted icsa to the outer membrane at wild-type levels. this suggests that icsa adopts an altered conformation in the outer membrane of the degp mutant with reduced exposure on the cell surface. icsa is, therefore, unlikely to be accessible to actin-nucleating proteins within the eukaryotic cell cy ... | 2007 | 17526712 |
| [using neosmectin in the complex therapy of patients with acute intestinal infections]. | 2007 | 17539357 | |
| control and regulation of kple1 prophage site-specific recombination: a new recombination module analyzed. | kple1 is one of the 10 prophage regions of escherichia coli k12, located at 2464 kb on the chromosome. kple1 is defective for lysis, but it is fully competent for excisive recombination. in this study, we have mapped the binding sites of the recombination proteins, namely ints, tori, and ihf on attl and attr, and the organization of these sites suggests that the intasome is architecturally different from the lambda canonical form. we also measured the relative contribution of these proteins to b ... | 2007 | 17545146 |
| screening methods used to determine the anti-microbial properties of aloe vera inner gel. | the emergence of antibiotic resistant bacterial strains is a growing problem and is an important concern for patients, physicians, healthcare managers, and policymakers as it results in poorer health and economic outcomes. this has led to an urgent global call for new antimicrobial drugs, particularly from natural resources. we have been studying the antimicrobial properties of the inner leaf gel component of aloe barbadensis miller and have used a number of different, simple in vitro assays to ... | 2007 | 17560318 |
| the inner gel component of aloe vera suppresses bacterial-induced pro-inflammatory cytokines from human immune cells. | the present study was carried out to examine the anti-inflammatory activity of the inner leaf gel component of aloe barbadensis miller. a simple in vitro assay was designed to determine the effect of the inner gel on bacterial-induced pro-inflammatory cytokine production, namely tnf-alpha and il-1 beta, from peripheral blood leukocytes stimulated with shigella flexneri or lps. this report describes the suppression of both cytokines with a freeze-dried inner gel powder and a commercial health dri ... | 2007 | 17560326 |
| antimicrobial activity of a series of thiosemicarbazones and their zn(ii) and pd(ii) complexes. | thirty-four thiosemicarbazones and s-alkyl thiosemicarbazones, and some of their zn(ii) and pd(ii) complexes were obtained and purified to investigate antimicrobial activity. mic values of the compounds were determined by the disc diffusion method against escherichia coli, klebsiella pneumoniae, proteus mirabilis, pseudomonas aeruginosa, salmonella typhi, shigella flexneri, staphylococcus aureus, s. epidermidis, and candida albicans. the thiosemicarbazones show antibacterial and antifungal effec ... | 2007 | 17571790 |
| preparation and characterization of translocator/chaperone complexes and their component proteins from shigella flexneri. | shigella flexneri causes a severe form of bacillary dysentery also known as shigellosis. onset of shigellosis requires bacterial invasion of colonic epithelial cells which is initiated by the delivery of translocator and effector proteins to the host cell membrane and cytoplasm, respectively, by the shigella type iii secretion system (ttss). the shigella translocator proteins, ipab and ipac, form a pore complex in the host cell membrane to facilitate effector delivery; however, prior to their se ... | 2007 | 17571858 |
| a deafness-associated mutant human connexin 26 improves the epithelial barrier in vitro. | a large proportion of recessive nonsyndromic hearing loss is due to mutations in the gjb2 gene encoding connexin 26 (cx26), a component of a gap junction. within different ethnic groups there are specific common recessive mutations, each with a relatively high carrier frequency, suggesting the possibility of heterozygous advantage. carriers of the r143w gjb2 allele, the most prevalent in the african population, present with a thicker epidermis than noncarriers. in this study, we show that (r143w ... | 2007 | 17581693 |
| genetic structure of the nada and nadb antivirulence loci in shigella spp. | comparison of nada and nadb in 14 shigella strains and enteroinvasive escherichia coli versus e. coli showed that at least one locus is altered in all strains. these observations explain the characteristic nicotinic acid auxotrophy of shigella organisms and are consistent with the previously identified antivirulence nature of these genes for these pathogens. | 2007 | 17586625 |
| shigella flexneri bacteriuria in a saudi child. | 1992 | 17587005 | |
| [study of antibiotic sensitivity of diarrheal microorganisms]. | as it was shown previously, detailed bacteriological analyses of 159 strains, among them museum and newly isolated strains of diarrheal patients from various clinics and bacteriology laboratories of tbilisi was carried out. study of antibiotic susceptibility of 52 strains of salmonella groups a, b, c, d, e and 42 shigella strains, among them 30 shigella flexneri and 12 shigella sonnei strains to 20 antibiotics and 1 chemical preparation was performed. 63% of salmonella strains were susceptible t ... | 2007 | 17595461 |
| analysis of the aerobactin and ferric hydroxamate uptake systems of yersinia pestis. | yersinia pestis genomes contain genes homologous to the aerobactin receptor (iuta) and biosynthetic genes (iucabcd) as well as the ferric hydroxamate uptake system (fhucdb) of escherichia coli. however, iuca is disrupted by a frameshift mutation. an e. coli strain carrying the cloned y. pestis aerobactin region was unable to produce aerobactin, but could use the siderophore as an iron source. repair of the frameshift mutation in iuca did not allow aerobactin production in e. coli or y. pestis. i ... | 2007 | 17600077 |
| nada and nadb of shigella flexneri 5a are antivirulence loci responsible for the synthesis of quinolinate, a small molecule inhibitor of shigella pathogenicity. | the evolution of bacterial pathogens from commensal organisms involves virulence gene acquisition followed by pathoadaptation to the new host, including inactivation of antivirulence loci (avl). avl are core ancestral genes whose expression is incompatible with the pathogenic lifestyle. previous studies identified cada (encoding lysine decarboxylase) as an avl of shigella spp. in this study, avl of shigella were identified by examining a phenotypic difference from its non-pathogenic ancestor, es ... | 2007 | 17600080 |
| risk areas and neighborhood-level risk factors for shigella dysenteriae 1 and shigella flexneri. | annually, there are 165 million cases of shigellosis resulting in 1.1 million deaths in the developing world. two species of the causative agent, shigella dysenteriae 1 and shigella flexneri, are responsible for acute diarrheal illness. vaccines are being developed against both but many questions remain about the disease burden, distribution of species in space and time, and community-level risk factors. this study answers two questions. what are the differences in neighborhood-level risk factor ... | 2008 | 17602851 |
| differences in the electrostatic surfaces of the type iii secretion needle proteins prgi, bsal, and mxih. | gram-negative bacteria use a needle-like protein assembly, the type iii secretion apparatus, to inject virulence factors into target cells to initiate human disease. the needle is formed by the polymerization of approximately 120 copies of a small acidic protein that is conserved among diverse pathogens. we previously reported the structure of the bsal needle monomer from burkholderia pseudomallei by nuclear magnetic resonance (nmr) spectroscopy and others have determined the crystal structure o ... | 2007 | 17617421 |
| distribution of serogroups and serotypes of multiple drug resistant shigella isolates. | summary | 2007 | 17622331 |
| site-specific modification of shigella flexneri virf mrna by trna-guanine transglycosylase in vitro. | shigella flexneri is an enteropathogen responsible for severe dysentery in humans. virf is a key transcriptional regulator that activates the expression of the downstream virulence factors required for cellular invasion and cell-to-cell spread of this pathogen. there are several environmental factors that induce the translation of virf including temperature, ph, osmolarity and post-transcriptional rna modification. durand and colleagues (vacc, a virulence-associated chromosomal locus of shigella ... | 2007 | 17626052 |
| study of predominant bacterial antigens triggering antibody response in salmonella reactive arthritis: apropos of a case. | reactive arthritis (rea) is a sterile arthritis triggered by distal mucosal infection, which suggests a contribution from bacterial products. the pathogenesis of rea is unclear. there are no international standards for the serological methods used to confirm rea. in the present work, we analyzed the predominant bacterial component that triggered an immune response in a 24-year-old woman with acute rea. the candidate bacterial trigger was investigated by measuring the antibacterial antibodies (al ... | 2007 | 17642539 |
| high prevalence of ctx-m-15 extended-spectrum beta-lactamase among contacts of patients with shigellosis due to shigella flexneri carrying ctx-m-15. | 2007 | 17646198 | |
| anaerobic regulation of shigella flexneri virulence: arca regulates fur and iron acquisition genes. | invasion and plaque formation in epithelial monolayers are routinely used to assess the virulence of shigella flexneri, a causative agent of dysentery. a modified plaque assay was developed to identify factors contributing to the virulence of s. flexneri under the anaerobic conditions present in the colon. this assay demonstrated the importance of the ferrous iron transport system feo, as well as the global transcription factors fur, arca, and fnr, for shigella plaque formation in anoxic environ ... | 2007 | 17660284 |
| identification of minor inner-membrane components of the shigella type iii secretion system 'needle complex'. | type iii secretion systems (t3sss or secretons) are central virulence factors of many gram-negative bacteria, used to inject protein effectors of virulence into eukaryotic host cells. their overall morphology, consisting of a cytoplasmic region, an inner- and outer-membrane section and an extracellular needle, is conserved in various species. a portion of the secreton, containing the transmembrane regions and needle, has been isolated biochemically and termed the 'needle complex' (nc). however, ... | 2007 | 17660405 |
| the acid-resistance pathways of shigella flexneri 2457t. | the stationary-phase acid-resistance pathways of shigella flexneri 2457t have not previously been studied. the two acid-resistance systems, the glutamate-dependent acid-resistance (gdar) and the oxidative pathways, reported elsewhere for escherichia coli and s. flexneri 3136, were both detected in s. flexneri 2457t. however, s. flexneri 2457t cells grown overnight under fermentative conditions and acid-shocked in minimal media in the absence of glutamate, an acid test often described as a negati ... | 2007 | 17660423 |
| shigella flexneri phagosomal escape is independent of invasion. | infections with salmonella enterica serovar typhimurium and shigella flexneri result in mucosal inflammation in response to epithelial cell invasion and macrophage cytotoxicity. these processes are mediated by type iii secretion systems encoded in homologous virulence loci in the two species, namely, salmonella pathogenicity island 1 (spi-1), carried in the genome, and the shigella entry region (ser), carried in a large virulence plasmid. here we show that spi-1 can functionally complement a del ... | 2007 | 17664266 |
| genes under positive selection in escherichia coli. | we used a comparative genomics approach to identify genes that are under positive selection in six strains of escherichia coli and shigella flexneri, including five strains that are human pathogens. we find that positive selection targets a wide range of different functions in the e. coli genome, including cell surface proteins such as beta barrel porins, presumably because of the involvement of these genes in evolutionary arms races with other bacteria, phages, and/or the host immune system. st ... | 2007 | 17675366 |
| escherichia coli, shigella and salmonella species in acute diarrhoea in hamedan, islamic republic of iran. | this study investigated the frequency of escherichia col, shigella and salmonella species in stool specimens from patients with diarrhoea presenting to health centres in hamedan province, islamic republic of iran. from 144 samples, shigella strains were isolated in 17 cases (11.8%): 10 sh. flexneri, 3 sh. sonnei, 2 sh. boydii and 2 untyped strains. no salmonella strains were isolated. using molecular diagnostic methods, diarrheogenic e. coli were detected in 37 cases (25.7%), the majority were e ... | 2007 | 17684844 |
| [ekiri syndrome complicating shigellosis]. | 2007 | 17692219 | |
| [intrafamilial outbreak of shigella flexneri gastroenteritis in madrid]. | 2007 | 17692266 |