Publications
Title | Abstract | Year Filter | PMID(sorted descending) Filter |
---|
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 |
[pathogens trapped in neutrophils nets]. | 2007 | 17502056 | |
[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 |
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 |
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 |
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 |
shigella flexneri type 2 infection in captive nonhuman primates. | 1985 | 17422604 | |
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 |
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 |
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 |
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 |
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 |
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 |
[shigella flexneri modulates host cell epigenetic information as a strategy to shape the transcriptional response]. | 2007 | 17349276 | |
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 |
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 |
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 |
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 |
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 |
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 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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
[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 |
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 |
[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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
[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 |
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 |
[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 |
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 |
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 |
crystal structure of the diadenosine tetraphosphate hydrolase from shigella flexneri 2a. | 2006 | 17006950 | |
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 |
quinine sulfate inhibits invasion of salmonella typhimurium and shigella flexneri: a preliminary study. | 2006 | 16987134 | |
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 |
plasmid-mediated quinolone resistance determinant qnrs in enterobacter cloacae. | pcr was used to investigate the occurrence of the plasmid-encoded quinolone resistance determinants qnra and qnrs among diarrhoeagenic enterobacterial isolates recovered from hanoi, vietnam, during the period march 2001 to april 2002. in total, 162 escherichia coli isolates, 28 shigella isolates and three enterobacter cloacae isolates were negative for qnra, while a single ent. cloacae isolate harboured a 50-kb qnrs-positive conjugative plasmid. cloning and sequencing identified a qnrs gene brac ... | 2006 | 16961640 |
visible-light-induced bactericidal activity of a nitrogen-doped titanium photocatalyst against human pathogens. | the antibacterial activity of photocatalytic titanium dioxide (tio(2)) substrates is induced primarily by uv light irradiation. recently, nitrogen- and carbon-doped tio(2) substrates were shown to exhibit photocatalytic activities under visible-light illumination. their antibacterial activity, however, remains to be quantified. in this study, we demonstrated that nitrogen-doped tio(2) substrates have superior visible-light-induced bactericidal activity against escherichia coli compared to pure t ... | 2006 | 16957236 |
characterization of ferric and ferrous iron transport systems in vibrio cholerae. | vibrio cholerae has multiple iron acquisition systems, including tonb-dependent transport of heme and of the catechol siderophore vibriobactin. strains defective in both of these systems grow well in laboratory media and in the infant mouse intestine, indicating the presence of additional iron acquisition systems. previously uncharacterized potential iron transport systems, including a homologue of the ferrous transporter feo and a periplasmic binding protein-dependent atp binding cassette (abc) ... | 2006 | 16952942 |
expression, limited proteolysis and preliminary crystallographic analysis of ipad, a component of the shigella flexneri type iii secretion system. | ipad, the putative needle-tip protein of the shigella flexneri type iii secretion system, has been overexpressed and purified. crystals were grown of the native protein in space group p2(1)2(1)2(1), with unit-cell parameters a = 55.9, b = 100.7, c = 112.0 a, and data were collected to 2.9 a resolution. analysis of the native patterson map revealed a peak at 50% of the origin on the harker section v = 0.5, suggesting twofold non-crystallographic symmetry parallel to the b crystallographic axis. a ... | 2006 | 16946465 |
[ultrastructural changes in shigella flexneri cells during interaction with bacteriocinogenic lactobacillus acidophilus]. | results of electron-microscopic examination of shigella flexneri cells, subjected to influence the bacteriocin-producing lactobacillus acidophilus bacteria are presented. the response of shigellae to bacteriocinogenic lactobacilli was shown both on cellular and population levels. on population level the correlation of various morphological types of shigella cells with increase of involution, lysing and resting forms is revealed. at a cellular level the specific ultrastructural changes of shigell ... | 2006 | 16941871 |
mobilizable incq-related plasmid carrying a new quinolone resistance gene, qnrs2, isolated from the bacterial community of a wastewater treatment plant. | plasmid-encoded quinolone resistance was previously reported for different bacteria isolated from patients not only in the united states and asia but also in europe. here we describe the isolation, by applying a new selection strategy, of the quinolone resistance plasmid pgnb2 from an activated sludge bacterial community of a wastewater treatment plant in germany. the hypersensitive escherichia coli strain kam3 carrying a mutation in the multidrug efflux system genes acrab was transformed with t ... | 2006 | 16940104 |
complete nucleotide sequence of pk245, a 98-kilobase plasmid conferring quinolone resistance and extended-spectrum-beta-lactamase activity in a clinical klebsiella pneumoniae isolate. | a plasmid containing the qnrs quinolone resistance determinant and the gene encoding the shv-2 beta-lactamase has been discovered from a clinical klebsiella pneumoniae strain isolated in taiwan. the complete 98-kb sequence of this plasmid, designated pk245, was determined by using a whole-genome shotgun approach. transfer of pk245 conferred low-level resistance to fluoroquinolones in electroporant escherichia coli epi300. the sequence of the immediate region surrounding qnrs in pk245 is nearly i ... | 2006 | 16940067 |
modulation of phosphoinositide metabolism by pathogenic bacteria. | phosphoinositide metabolism plays a pivotal role in the regulation of receptor-mediated signal transduction, actin remodelling and membrane dynamics. phosphoinositides co-ordinate these processes by recruiting protein effectors to distinct cellular membranes in a time- and organelle-dependent manner. intracellular bacterial pathogens interfere with phosphoinositide metabolism to direct their entry into eukaryotic cells, form replication-permissive vacuoles, modulate apoptosis, or trigger fluid s ... | 2006 | 16939534 |
effect of lactoferrin on enteroaggregative e. coli (eaec). | we previously demonstrated that lactoferrin inhibits adherence of enteropathogenic escherichia coli to hep-2 cells and decreases invasiveness of shigella flexneri in hela cells by disruption of the type iii secretory system (ttss) of both enteropathogens. to determine whether these effects were specific to the ttss, we assessed the activity of bovine lactoferrin on enteroaggregative e. coli (eaec), enteropathogens whose virulence is not ttss dependent. bovine lactoferrin at a concentration of 1. ... | 2006 | 16936809 |
reciprocal transcriptional and posttranscriptional growth-phase-dependent expression of sfh, a gene that encodes a paralogue of the nucleoid-associated protein h-ns. | the inchi1 self-transmissible plasmid psf-r27 from shigella flexneri 2a strain 2457t harbors sfh, a gene that codes for a protein with strong amino acid sequence homology to the global transcription regulator and nucleoid-associated protein h-ns and to its paralogue, stpa. previously, we discovered that the expression of sfh mrna is growth phase dependent such that in cultures growing in lennox broth at 37 degrees c, the transcript is readily detectable in the early stages of exponential growth ... | 2006 | 16936022 |
structure of yidb protein from shigella flexneri shows a new fold with homeodomain motif. | 2006 | 16927377 | |
cholesterol is required to trigger caspase-1 activation and macrophage apoptosis after phagosomal escape of shigella. | pro-inflammatory macrophage apoptosis is pivotal in the aetiology of bacillary dysentery, an acute inflammatory diarrhoea caused by shigella spp. s. flexneri triggers its uptake by macrophages, escapes the phagosome and kills the host cell by a cytotoxic pathway, which activates and requires caspase-1 [interleukin (il)-1beta-converting enzyme] and releases mature il-1beta. the bacterial type iii-secreted translocator/effector protein ipab triggers cell death and directly binds to caspase-1. here ... | 2007 | 16925787 |
fishmeal extract bile salt lactose agar--a differential medium for enteric bacteria. | fishmeal extract bile salt lactose agar (febla), a new differential medium for enteric bacteria was developed and evaluated for its ability to grow and differentiate lactose fermenters (lf) from non-lactose fermenters (nlf) in comparison with macconkeys agar. performance of febla was at par with the latter. on febla medium, the contrast between lf and nlf colonies was pronounced and klebsiella pneumoniae produced more mucoid colonies than on macconkeys agar (hi media). unlike macconkeys agar, a ... | 2006 | 16924840 |
structural characterization of enterobactin hydrolase iroe. | the proliferation of many pathogenic bacteria is limited by the scarcity of soluble iron in their environment. many of these bacteria scavenge iron by synthesizing and exporting small molecule siderophores that chelate iron. iron-bound siderophores are subsequently imported for metabolic processing. three related serine hydrolases have been characterized biochemically in this pathway: fes, irod, and iroe. here, we report the crystal structure of iroe from uropathogenic escherichia coli cft073. t ... | 2006 | 16922493 |
structural organization of the needle complex of the type iii secretion apparatus of shigella flexneri. | the secretion apparatus known as the needle complex (nc) from the bacterium shigella flexneri was studied by single particle electron microscopy. the isolated intact nc appears in projection to be composed of a basal body consisting of seven rings and a protruding needle appendage. a comparison of averaged projections of the intact nc and its fragments revealed the organization of the nc into several major subcomplexes. one of these lacks an inner membrane ring of the basal body but still presen ... | 2007 | 16920362 |
shigella vulvovaginitis in a prepubertal child. | 2006 | 16912629 | |
characterization of shigella strains in iran by plasmid profile analysis and pcr amplification of ipa genes. | to characterize shigella clinical strains, we studied 82 shigella strains recovered from 719 stool samples of patients with bloody diarrhea in shiraz, iran, over the period from april to october 2003. serological assay classified the shigella isolates as follows: 61 (74.39%) shigella sonnei isolates, 16 (19.51%) shigella flexneri isolates, 3 (3.65%) shigella boydii isolates, and 2 (2.43%) shigella dysenteriae isolates. in an antibiogram test, all shigella strains were susceptible to ceftazidime, ... | 2006 | 16891506 |
comprehensive proteomic analysis of shigella flexneri 2a membrane proteins. | shigella flexneri is the causative agent of most shigellosis cases in developing countries. we used different proteolytic enzymes to selectively shave the protruding proteins on the surface of purified bacterial membrane sheets or vesicles, and recovered peptides were subsequently identified using 2-d lc-ms/ms. as a result, a total of 666 proteins were unambiguously assigned, including 159 integral membrane proteins, 35 outer membrane proteins and 114 proteins previously annotated as hypothetica ... | 2006 | 16889407 |
molecular model of a type iii secretion system needle: implications for host-cell sensing. | type iii secretion systems are essential virulence determinants for many gram-negative bacterial pathogens. the type iii secretion system consists of cytoplasmic, transmembrane, and extracellular domains. the extracellular domain is a hollow needle protruding above the bacterial surface and is held within a basal body that traverses both bacterial membranes. effector proteins are translocated, via this external needle, directly into host cells, where they subvert normal cell functions to aid inf ... | 2006 | 16888041 |
increasing single and multi-antibiotic resistance in shigella species isolated from shigellosis patients in sana'a, yemen. | the epidemiology and antibiotic susceptibility of shigella species changes over time. updated susceptibility knowledge is necessary for appropriate empirical antibiotic treatment. thus, this research aimed to study these changes in 2 time periods with an interval of 10 years. | 2006 | 16883444 |
trend and disease burden of bacillary dysentery in china (1991-2000). | we aimed to determine the burden of bacillary dysentery in china, its cross-regional variations, trends in morbidity and mortality, the causative bacterial species and antimicrobial resistance patterns. | 2006 | 16878230 |
shigella and autophagy. | bacterial invasion of eukaryotic cells, and host recognition and elimination of the invading bacteria, determines the fate of bacterial infection. once inside mammalian cells, many pathogenic bacteria enter the host cytosol to escape from the lytic compartment and gain a replicative niche. recent studies indicate that autophagy also recognizes intracellular bacteria. although autophagy is a conserved membrane trafficking pathway in eukaryotic cells that sequesters undesirable or recyclable cytop ... | 2006 | 16874102 |
simple enzymatic in situ generation of dihydroxyacetone phosphate and its use in a cascade reaction for the production of carbohydrates: increased efficiency by phosphate cycling. | a new enzymatic method for the generation of dihydroxyacetone phosphate (dhap) using the acid phosphatase from shigella flexneri (phon-sf) and the cheap phosphate donor pyrophosphate (ppi) is described. the utility of this method was demonstrated in an aldolase-catalyzed condensation carried out in one pot in which dhap was generated and coupled to propionaldehyde to give a yield of 53% of the isolated dephosphorylated end product. | 2006 | 16872211 |
spectroscopic and calorimetric analyses of invasion plasmid antigen d (ipad) from shigella flexneri reveal the presence of two structural domains. | shigella flexneri is a facultative intracellular pathogen that causes severe gastroenteritis in humans. invasion plasmid antigen d (ipad) is an essential participant in shigella invasion of intestinal cells, but no detailed structural information is available to help understand the proposed role of ipad in invasion or its interaction with other invasion proteins. therefore, the secondary and tertiary structure and thermal stability of ipad as well as selected ipad deletion mutants were investiga ... | 2006 | 16866368 |
role and regulation of the shigella flexneri sit and mnth systems. | shigella flexneri possesses at least two putative high-affinity manganese acquisition systems, sitabcd and mnth. mutations in the genes encoding the components of both of these systems were constructed in s. flexneri. the sita mnth mutant showed reduced growth, relative to the wild type, in luria broth (l broth) containing the divalent metal chelator ethylene diamino-o-dihydroxyphenyl acetic acid, and the addition of either iron or manganese restored growth to the level of the wild-type strain. ... | 2006 | 16861654 |
ipad localizes to the tip of the type iii secretion system needle of shigella flexneri. | shigella flexneri, the causative agent of shigellosis, is a gram-negative bacterial pathogen that initiates infection by invading cells within the colonic epithelium. contact with host cell surfaces induces a rapid burst of protein secretion via the shigella type iii secretion system (ttss). the first proteins secreted are ipad, ipab, and ipac, with ipab and ipac being inserted into the host cell membrane to form a pore for translocating late effectors into the target cell cytoplasm. the resulti ... | 2006 | 16861624 |
enhancement of mice susceptibility to infection with listeria monocytogenes by the treatment of morphine. | the effect of morphine on the susceptibility of balb/c mice to diarrheagenic escherichia coli, shigella flexneri, listeria monocytogenes, salmonella enteritidis, yersinia enterocolitica, was examined via the intraperitoneal inoculation. morphine treatment increased the susceptibility to s. enteritidis and l. monocytogenes, resulting in bacteremia and central nervous system (cns) invasion (for l. monocytogenes), while the infection with other bacteria did not show the systemic dissemination in th ... | 2006 | 16858145 |
studies on pongamia pinnata (l.) pierre leaves: understanding the mechanism(s) of action in infectious diarrhea. | while data are available on the effect of medicinal plants on intestinal motility and their antibacterial action, there is a paucity of information on their mode of action on various aspects of diarrheal pathogenicity, namely colonization to intestinal epithelial cells and production/action of enterotoxins. crude decoction of dried leaves of pongamia pinnata was evaluated for its antimicrobial (antibacterial, antigiardial and antirotaviral) effect; and its effect on production and action of ente ... | 2006 | 16845722 |
inactivation of gram-negative bacteria in milk and banana juice by hen egg white and lambda lysozyme under high hydrostatic pressure. | the effect of hen egg white lysozyme (hewl) and bacteriophage lambda lysozyme (lal) in combination with high pressure (hp) treatment on the inactivation of four gram-negative bacteria (escherichia coli o157:h7, shigella flexneri, yersinia enterocolitica and salmonella typhimurium), was studied in skim milk (ph 6.8; a(w) 0.997) and in banana juice (ph 3.8; a(w) 0.971). in the absence of lysozymes, s. flexneri was more sensitive to hp in milk than in banana juice, while the opposite was observed f ... | 2006 | 16843561 |
surveillance for bacterial diarrhea and antimicrobial resistance in rural western kenya, 1997-2003. | diarrhea is a major cause of preventable illness in sub-saharan africa. although most cases of bacterial gastroenteritis do not require antimicrobial treatment, antimicrobial use is widespread. we examined the bacterial causes of diarrhea and monitored antimicrobial susceptibilities of isolates through clinic-based surveillance in a rural kenyan community. | 2006 | 16838225 |