Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| cytotoxicity and interleukin-1beta processing following shigella flexneri infection of human monocyte-derived dendritic cells. | shigella flexneri infection of macrophages (mphi) leads to activation of caspase-1 by the ipab virulence factor, which induces rapid cell death and release of mature il-1beta. here we show that s. flexneri infection of human monocyte-derived dendritic cells (dc) also results in rapid ipab-dependent death. cytotoxicity is only partially blocked by the caspase-1 inhibitor yvad, but completely blocked by the pan-caspase inhibitor z-vad. cytotoxicity is also partially blocked by glycine without affe ... | 2002 | 11981835 |
| development of an oral prime-boost strategy to elicit broadly neutralizing antibodies against hiv-1. | given the increasing incidence of hiv-1 infection world-wide, an affordable, effective vaccine is probably the only way that this virus will be contained. accordingly, our group is developing an oral prime-boost strategy with the primary goal of eliciting broadly neutralizing antibodies against hiv-1 to provide sterilizing immunity for this virus. our secondary goal is to elicit broadly cross-reactive anti-viral cd8(+) t cells by this strategy to blunt any breakthrough infections that occur afte ... | 2002 | 11983256 |
| bromoperoxidase activity of vanadate-substituted acid phosphatases from shigella flexneri and salmonella enterica ser. typhimurium. | vanadium haloperoxidases and the bacterial class a nonspecific acid phosphatases have a conserved active site. it is shown that vanadate-substituted recombinant acid phosphatase from shigella flexneri (phon-sf) and salmonella enterica ser. typhimurium (phon-se) in the presence of h2o2 are able to oxidize bromide to hypobromous acid. vanadate is essential for this activity. the kinetic parameters for the artificial bromoperoxidases have been determined. the km value for h2o2 is about the same as ... | 2002 | 11985594 |
| two msbb genes encoding maximal acylation of lipid a are required for invasive shigella flexneri to mediate inflammatory rupture and destruction of the intestinal epithelium. | shigella flexneri is a gram-negative pathogen that invades and causes inflammatory destruction of the human colonic epithelium, thus leading to bloody diarrhea and dysentery. a type iii secretion system that delivers effector proteins into target eukaryotic cells is largely responsible for cell and tissue invasion. however, the respective role of this invasive phenotype and of lipid a, the endotoxin of the shigella lps, in eliciting the inflammatory cascade that leads to rupture and destruction ... | 2002 | 11994481 |
| incidence and molecular analysis of vibrio cholerae associated with cholera outbreak subsequent to the super cyclone in orissa, india. | an epidemiological study was carried out to find out the aetiological agent for diarrhoeal disorders in the cyclone and flood affected areas of orissa, india. rectal swabs collected from 107 hospitalized diarrhoea patients were bacteriologically analysed to isolate and identify the various enteropathogens. detection of toxic genes among e. coli and v. cholerae was carried out by polymerase chain reaction (pcr) assay. of the 107 rectal swabs analysed, 72.3% were positive for v. cholerae o1 ogawa, ... | 2002 | 12002529 |
| rhamnose-binding lectins from steelhead trout (oncorhynchus mykiss) eggs recognize bacterial lipopolysaccharides and lipoteichoic acid. | the interaction between bacteria and three l-rham-nose-binding lectins, named stl1, stl2, and stl3, from steelhead trout (oncorhynchus mykiss) eggs was investigated. although stls bound to most gram-negative and gram-positive bacteria, they agglutinated only escherichia coli k-12 and bacillus subtilis among the bacteria tested. the binding was inhibited by l-rhamnose. stls bound to distinct serotypes of lipopolysaccharides (lpss), and showed much higher binding activities to smooth-type lpss of ... | 2002 | 12005056 |
| regulation of the overlapping pic/set locus in shigella flexneri and enteroaggregative escherichia coli. | most strains of shigella flexneri 2a and enteroaggregative escherichia coli carry a highly conserved chromosomal locus which encodes a 109-kda secreted mucinase (called pic) and, on the opposite strand in overlapping fashion, an oligomeric enterotoxin called shet1, encoded by the seta and setb genes. here, we characterize the genetic regulation of these overlapping genes. our data suggest that pic and the setba loci are transcribed as complementary 4-kb mrna species. the major pic promoter is ma ... | 2002 | 12010980 |
| construction, characterization, and animal testing of wrsd1, a shigella dysenteriae 1 vaccine. | wrsd1 is a shigella dysenteriae 1 vaccine containing deletions of the virg(icsa) gene required for intercellular spreading and a 20-kb chromosomal region encompassing the shiga toxin genes (stxab). wrsd1 was constructed from s. dysenteriae 1 strain 1617 that was originally isolated during the 1968 to 1969 epidemic of shiga dysentery in guatemala. the virg(icsa) deletion was constructed from a streptomycin-resistant (str(r)) mutant of 1617 by a filter mating procedures using a virg(icsa) deletion ... | 2002 | 12010984 |
| the dynamics of actin-based motility depend on surface parameters. | in cells, actin polymerization at the plasma membrane is induced by the recruitment of proteins such as the arp2/3 complex, and the zyxin/vasp complex. the physical mechanism of force generation by actin polymerization has been described theoretically using various approaches, but lacks support from experimental data. by the use of reconstituted motility medium, we find that the wiskott aldrich syndrome protein (wasp) subdomain, known as vca, is sufficient to induce actin polymerization and move ... | 2002 | 12015607 |
| survival and growth of shigella flexneri, salmonella enterica serovar enteritidis, and vibrio cholerae o1 in reconstituted infant formula. | formula feeding is an alternative method to prevent mother-to-child infection with human immunodeficiency virus through breast-feeding in developing countries. growth of bacterial pathogens in reconstituted infant formula has become a health hazard when contaminated water is used for rehydration. this study was conducted to assess bacterial safety risk of using contaminated water to reconstitute infant formula. survival and growth characteristics were determined for three bacterial pathogens, vi ... | 2002 | 12224592 |
| effect of organic acids and temperature on survival of shigella flexneri in broth at ph 4. | the survival of bacterial pathogens in acidified foods depends not only on the hydrogen ion concentration, but also on the type of acid and the storage temperature. shigella flexneri is a foodborne pathogen that is acid tolerant. the survival of s. flexneri 5348 in brain heart infusion broth supplemented with 0.04 m acetic, citric, lactic, malic, or tartaric acid and adjusted to ph 4 with hci or naoh was studied. the control medium was brain heart infusion broth adjusted to ph 4 with hci. statio ... | 2002 | 12233851 |
| conversion of ptdins(4,5)p(2) into ptdins(5)p by the s.flexneri effector ipgd reorganizes host cell morphology. | phosphoinositides play a central role in the control of several cellular events including actin cytoskeleton organization. here we show that, upon infection of epithelial cells with the gram-negative pathogen shigella flexneri, the virulence factor ipgd is translocated directly into eukaryotic cells and acts as a potent inositol 4-phosphatase that specifically dephosphorylates phosphatidylinositol 4,5-bisphosphate [ptdins(4,5)p(2)] into phosphatidylinositol 5-monophosphate [ptdins(5)p] that then ... | 2002 | 12356723 |
| epithelial inflammation response induced by shigella flexneri depends on mucin gene expression. | the protective effects of different mucin gene profiles on gut protection were assessed by the evaluation of tnfalpha production by intestinal epithelial cells infected by shigella flexneri. three ht-29 cell lines were used: ht29-g(-) (enterocyte-like cells, secreting no mucins), ht29-fu (highly expressing muc2 and muc4) and ht29-mtx (highly expressing muc3 and muc5ac). these cells were infected either by an invasive (m90t) or the control isogenic (bs176) strains of s. flexneri, and tnfalpha mrn ... | 2002 | 12361911 |
| [dysentery in poland in 2000]. | the notified number of dysentery cases is still falling down since the year 1995 when bacteriological examination of feces for diagnostic purposes lost free of charge status obtained in 1928 under the legislation act of infectious disease investigation and obligatory registration. only 121 dysentery cases were notified in the year 2000 (incidence 0.31/100,000 population), while 292 cases were notified in 1999 (incidence 0.76/100,000). no one death case was notified. only 2 outbreaks (one due to ... | 2002 | 12371362 |
| septic shock associated with shigella flexneri dysentery. | septic shock is a very unusual presentation of shigella infection. we describe a 3-y-old child who developed severe septic shock and severe encephalopathy during an episode of dysentery caused by shigella flexneri. | 2002 | 12374365 |
| shigella flexneri degp facilitates icsa surface expression and is required for efficient intercellular spread. | a degp mutant of shigella flexneri was identified in a screen for insertion mutants that invaded cultured cells but did not form wild-type plaques in monolayers. the degp mutant sm1100 invaded henle cells at wild-type levels and induced apoptosis in macrophages but formed smaller plaques than those formed by wild-type s. flexneri in confluent monolayers of henle and caco-2 cells. the proportion of sm1100 bacteria with icsa localized to the bacterial pole, a process required for actin polymerizat ... | 2002 | 12379715 |
| enteropathogens associated with acute diarrhea in community and hospital patients in jakarta, indonesia. | the prevalence of bacteria, parasite and viral pathogens in 3875 patients with diarrhea in community and hospital settings from march 1997 through august 1999 in jakarta, indonesia was determined using routine bacteriology and molecular assay techniques. bacterial pathogens isolated from hospital patients were, in decreasing frequency, vibrio cholerae o1, shigella flexneri, salmonella spp. and campylobacter jejuni, while s. flexneri, v. cholerae o1, salmonella spp. and c. jejuni were isolated fr ... | 2002 | 12381465 |
| genetics of isoprenoid biosynthesis in paracoccus zeaxanthinifaciens. | the genes coding for all the enzymes involved in the conversion of acetyl-coa to farnesyl diphosphate (fpp) in the zeaxanthin-producing bacterium paracoccus zeaxanthinifaciens were cloned and characterized. two genes encoding enzymes catalysing the condensation of two acetyl-coa molecules to acetoacetyl-coa were found. the six enzymes involved in the conversion of acetyl-coa and acetoacetyl-coa to isopentenyl diphosphate (ipp) and dimethylallyl diphosphate (dmapp) are grouped in an operon, desig ... | 2002 | 12384294 |
| genome sequence of shigella flexneri 2a: insights into pathogenicity through comparison with genomes of escherichia coli k12 and o157. | we have sequenced the genome of shigella flexneri serotype 2a, the most prevalent species and serotype that causes bacillary dysentery or shigellosis in man. the whole genome is composed of a 4 607 203 bp chromosome and a 221 618 bp virulence plasmid, designated pcp301. while the plasmid shows minor divergence from that sequenced in serotype 5a, striking characteristics of the chromosome have been revealed. the s.flexneri chromosome has, astonishingly, 314 is elements, more than 7-fold over thos ... | 2002 | 12384590 |
| selection of shigella flexneri candidate virulence genes specifically induced in bacteria resident in host cell cytoplasm. | we describe an in vivo expression technology (ivet)-like approach, which uses antibiotic resistance for selection, to identify shigella flexneri genes specifically activated in bacteria resident in host cell cytoplasm. this procedure required construction of a promoter-trap vector containing a synthetic operon between the promoterless chloramphenicol acetyl transferase (cat) and lacz genes and construction of a library of plasmids carrying transcriptional fusions between s. flexneri genomic frag ... | 2002 | 12390353 |
| doc-mediated cell killing in shigella flexneri using a c1/laci controlled expression system. | in this report we describe the development of a highly stringent and dually regulated promoter system for shigella flexneri. dual regulation was provided by utilizing a promoter susceptible to control by the bacteriophage p1 temperature-sensitive c1 repressor that in turn was under the transcriptional control of laci. the level of induction/repression ratios observed was up to 3700-fold in s. flexneri. the general utility of this promoter system was evaluated by demonstrating that the bacterioph ... | 2002 | 12399040 |
| [the role of hla-b27 molecules in the pathogenesis of ankylosing spondylitis]. | ankylosing spondylitis (as) is characterised by the strongest association with an hla antigen ever described for any disease. it represents therefore the ideal model for the understanding of the link between immune-mediated diseases and the hla system. the role of hla-b27 in the pathogenesis of as will be discussed focusing on the recently described higher expression of these molecules in patients with as compared with healthy controls. | 2002 | 12404037 |
| [acute diarrhea outbreak caused by shigella flexneri at a school in madrid, cundinamarca: phenotypic and genotypic characterization of the isolates]. | shigellosis is an acute diarrhoeal disease that is the main cause of morbidity and mortality in developing countries. in 1997, the colombian instituto nacional de salud microbiology group organized a network surveillance program with the country's public health laboratories (phls) to monitor the principal etiological agents responsible for acute diarrhoeal disease. in may, 2001, the phl of the state of cundinamarca reported a food poisoning outbreak involving an elementary school community. the ... | 2002 | 12404927 |
| shigella flexneri bacteraemia in an immunocompetent male treated with oral ciprofloxacin. | 2002 | 12423618 | |
| shigella isolation in vellore, south india (1997-2001). | shigellosis has been a major cause of dysentery for many years at vellore, south india. in the last two years the number of shigella being isolated from samples of faeces from patients with diarrhoea has decreased (5% isolation rate in 1997 to 3.9% in 2001), although the microbiological methods and media used have not changed. also, the nalidixic acid (na) resistance has increased for s. sonnei (now 94%). this is noteworthy, since na has been recommended for the empirical treatment of patients s ... | 2002 | 12424931 |
| molecular recognition of oligosaccharide epitopes by a monoclonal fab specific for shigella flexneri y lipopolysaccharide: x-ray structures and thermodynamics. | the antigenic recognition of shigella flexneri o-polysaccharide, which consists of a repeating unit abcd [-->2)-alpha-l-rhap-(1-->2)-alpha-l-rhap-(1-->3)-alpha-l-rhap-(1-->3)-beta-d-glcpnac-(1-->], by the monoclonal antibody sya/j6 (igg3, kappa) has been investigated by crystallographic analysis of the fab domain and its two complexes with two antigen segments (a pentasaccharide rha a-rha b-rha c-glcnac d-rha a' and a modified trisaccharide rha b-rha c-glcnac d in which rha c* is missing a c2-oh ... | 2002 | 12427018 |
| neutrophil elastase targets virulence factors of enterobacteria. | shigellae cause bacillary dysentery, a bloody form of diarrhoea that affects almost 200 million people and causes nearly 2 million deaths per year. shigella invades the colonic mucosa, where it initiates an acute inflammation, rich in neutrophils, that initially contributes to tissue damage and eventually resolves the infection. neutrophils are phagocytic cells that kill microorganisms but it is unclear how neutrophils control pathogenic bacteria expressing virulence factors that manipulate host ... | 2002 | 12018205 |
| distinct recent lineages of the stra- strb streptomycin-resistance genes in clinical and environmental bacteria. | we report the linkage of the stra-strb streptomycin-resistance genes with class 1 integron sequences on pstr1, a 75-kb multiple antibiotic-resistance plasmid from shigella flexneri. stra-strb had previously been detected only within tn 5393, a tn 3-family transposon, and on small nonconjugative broad-host-range plasmids such as rsf1010. the geographic range of tn 5393 was also extended to pseudomonas spp. isolated from apple trees in new zealand and soil in the usa. comparative sequence analyses ... | 2002 | 12029529 |
| the effect of nacl on survival of shigella flexneri in broth as affected by temperature and ph. | shigella, a major foodborne pathogen, survives well in salt-containing environments. however, systematic data are scarce. we studied the behavior of shigella flexneri 5348 in brain heart infusion broth (ph 4 to 6) containing 0.5 to 8% nacl. stationary-phase cells were inoculated into sterile media at initial concentrations of 6 to 7 log10 cfu/ml and incubated at 12 to 37 degrees c. bacterial population sizes were determined periodically by plate counts. survivor curves were derived from plate co ... | 2002 | 12030287 |
| inorganic polyphosphate is essential for long-term survival and virulence factors in shigella and salmonella spp. | the importance of inorganic polyphosphate (poly p) and poly p kinase (ppk), the enzyme principally responsible for its synthesis, has been established previously for stationary-phase survival of escherichia coli and virulence in pseudomonas aeruginosa. the gene (ppk) that encodes ppk is highly conserved among many bacterial pathogens, including shigella and salmonella spp. in view of the phylogenetic similarity of the enteropathogens and the frequency with which virulence factors are expressed i ... | 2002 | 12032342 |
| mucosal dna vaccination with highly attenuated shigella is superior to attenuated salmonella and comparable to intramuscular dna vaccination for t cells against hiv. | an immunization strategy using attenuated bacteria to deliver dna vaccine plasmids to mucosal sites may induce protective t cell responses against sexual hiv transmission. in a murine intranasal (i.n.) immunization model, we demonstrate that transiently persistent deltaasd shigella flexneri strain 15d harboring dna vaccines induces hiv- and siv-specific gamma interferon (ifn-gamma) producing cd8+ t cells among splenocytes more efficiently than either a longer persisting deltaarod salmonella typh ... | 2002 | 12036602 |
| wild-type intracellular bacteria deliver dna into mammalian cells. | gene transfer in vitro from intracellular bacteria to mammalian phagocytic and non-phagocytic cells and in vivo in mice has been reported. the bacteria used as dna delivery vectors were engineered to lyze upon entry in the cell due to impaired cell wall synthesis for shigella flexneri and invasive escherichia coli, or production of a phage lysin for listeria mono- cytogenes. in vivo gene transfer was obtained with attenuated salmonella typhimurium and resulted in stimulation of mucosal immunity. ... | 2002 | 11906454 |
| prevalence of the sat gene among clinical isolates of shigella spp. causing travelers' diarrhea: geographical and specific differences. | 2002 | 11923399 | |
| development of a p1 phagemid system for the delivery of dna into gram-negative bacteria. | the inability to transform many clinically important gram-negative bacteria has hampered genetic studies addressing the mechanism of bacterial pathogenesis. this report describes the development and construction of a delivery system utilizing the broad-host-range transducing bacteriophage p1. the phagemids used in this system contain a p1 pac initiation site to package the vector, a p1 lytic replicon to generate concatemeric dna, a broad-host-range origin of replication and an antibiotic-resista ... | 2002 | 11932441 |
| [comparison of shigella susceptibility to commonly used antimicrobials in the temuco regional hospital, chile 1990 - 2001]. | the permanent surveillance of antimicrobial susceptibility of shigella sp in the temuco regional hospital, allowed us to define the empirical use of antimicrobials in dysenteric syndrome. | 2002 | 12434650 |
| evolution of multiresistance in nontyphoid salmonella serovars from 1984 to 1998 in argentina. | molecular evolution of multiresistance in nontyphoid salmonella spp. was investigated with 155 isolates obtained in argentina from 1984 to 1998. in 74 isolates obtained from 1984 to 1988 resistance was associated with the presence of tn3, tn9, class i (in0) and ii (tn7) integrons, and the aac(3)-iia gene. extended-spectrum cephalosporin (esc) resistance in salmonella spp. emerged in 1989, and 81 isolates resistant to at least one esc and one aminoglycoside were collected thereafter. among these, ... | 2002 | 12435702 |
| lactoferrin protects rabbits from shigella flexneri-induced inflammatory enteritis. | shigella species cause bacillary dysentery in humans by invasion, intracellular multiplication, spread to adjacent cells, and induction of brisk inflammatory responses in the intestinal epithelium. in vitro data suggest that lactoferrin, a glycoprotein present in human mucosal secretions, has a role in protection from bacterial enteric infections. we sought to determine the activity of lactoferrin in vivo, using the concentration present in human colostrum, to investigate its effect on the devel ... | 2002 | 12438385 |
| functional comparison of serine protease autotransporters of enterobacteriaceae. | the plasmid-encoded toxin (pet) of enteroaggregative escherichia coli (eaec) belongs to a family of high-molecular-weight serine protease autotransporters of enterobacteriaceae (spates) which also includes pic from eaec and shigella flexneri, espc from enteropathogenic e. coli, espp from enterohemorrhagic e. coli, sat from uropathogenic e. coli, tsh from avian pathogenic e. coli, and sepa from s. flexneri. phylogenetic analysis shows the spate proteins to represent a distinct subfamily of autotr ... | 2002 | 12438392 |
| identification of the cis-acting site involved in activation of promoters regulated by activity of the type iii secretion apparatus in shigella flexneri. | bacteria of shigella spp. use a virulence plasmid-encoded type iii secretion (tts) system to invade the colonic epithelium in humans. the activity of the tts apparatus is tightly regulated in the wild-type strain and is induced upon contact of bacteria with epithelial cells, whereas it is deregulated, i.e., constitutively active, in some mutants. under conditions of deregulated secretion, approximately 20 proteins are secreted, including vira, ospb to ospg, and at least three members of the ipah ... | 2002 | 12446624 |
| igg antibodies to enterobacteria 60 kda heat shock proteins in the sera of hla-b27 positive ankylosing spondylitis patients. | to study the association of hla-b27 and the igg response to the 60 kda hsps of klebsiella pneumoniae, yersinia enterocolitica, shigella flexneri, escherichia coli and salmonella typhi. | 2002 | 12455814 |
| purification and detection of shigella type iii secretion needle complex. | 2002 | 12474402 | |
| surveillance of bacterial pathogens of diarrhea disease in indonesia. | emerging or reemerging infections due to bacterial disease may be a local, regional or global problem. bacterial acute gastroenteritis is a potential cause of substantial morbidity in travelers and deployed u.s. military personnel. a surveillance study was conducted over a two-year period in indonesia among 6760 patients with debilitating diarrheal diseases. of the 6,760 patients, 587 (9%) of the patient stools were positive for bacteria. the proportions of bacteria isolated from the 587 patient ... | 2002 | 12493168 |
| [clinical and morphological aspects of shigellosis flexneri in patients with an aggravated premorbid state]. | the analysis of 10 fatal outcomes in patients with acute shigellosis during the period of 1999-2000 made it possible to find out that most of deceased shigellosis patients belonged to the group inclined to alcohol abuse and having initial alimentary disturbances. in 6 cases of acute shigellosis with fatal outcome the causative agent was s. flexneri 2a, in 2 cases--s. flexneri 3a, in 1--s. flexneri 4b. the main cause of fatal outcomes was accompanying double pneumonia. lesions of the intestinal t ... | 2002 | 12043161 |
| [molecular characterization of resistance mechanisms to chloramphenicol in shigella flexneri strains isolated from chilean children with acute diarrhea]. | chloramphenicol is one of the therapeutic options for shigellosis, but resistance to this antimicrobial is increasing. | 2002 | 12043369 |
| representational difference analysis uncovers a novel is10-like insertion element unique to pathogenic strains of yersinia enterocolitica. | the method of suppressive subtractive hybridization was employed to map out genomic differences between the highly pathogenic yersinia enterocolitica (ye) biogroup 1b, serotype o:8 strain (wa-314) and the closely related apathogenic y. enterocolitica biogroup 1a, serotype o:5 strain (nf-o). a novel is10-like element, is1330, uncovered by this technique was found to be uniquely present in high copy numbers among the highly pathogenic y. enterocolitica 1b strains, while a single copy of the elemen ... | 2002 | 12044683 |
| [studies on the actin-based spreading of shigella]. | 2002 | 12048885 | |
| molecular dissection of virb, a key regulator of the virulence cascade of shigella flexneri. | the virb protein is a key regulator of virulence gene expression in the facultative enteroinvasive pathogen shigella flexneri. while genetic evidence has shown that it is required for activation of transcription of virulence genes located on a 230-kb plasmid in this bacterium, hitherto, evidence that virb is a dna-binding protein has been lacking. although virb shows extensive homology to proteins involved in plasmid partitioning, it does not resemble any known conventional transcription factor. ... | 2002 | 11850420 |
| shigella flexneri interactions with the basolateral membrane domain of polarized model intestinal epithelium: role of lipopolysaccharide in cell invasion and in activation of the mitogen-activated protein kinase erk. | an early step governing shigella flexneri pathogenesis is the invasion of the colonic epithelium from the basolateral surface followed by disruption of the colonic epithelial barrier. despite recent insight into s. flexneri-host interactions, much remains to be determined regarding the nature of the initial contact between s. flexneri and the host epithelial basolateral membrane domain. since the lipopolysaccharide (lps) is located at the outermost part of the bacterial membrane, we considered t ... | 2002 | 11854195 |
| use of aflp, plasmid typing and phenotyping in a comparative study to assess genetic diversity of shigella flexneri strains. | shigella flexneri infections are one of the main causes of acute diarrhoea in cuba. twenty strains isolated from sporadic cases in nine different cuban provinces were characterized. serotyping, antibiotic-resistance typing, plasmid-typing and aflp-typing were used to determine their suitability for use in epidemiological studies of s. flexneri. the predominant serotypes were serotype 6 (35%) and serotype 2 (35%). eleven different plasmid profiles were detected (diversity index = 0.92). aflp-typi ... | 2002 | 12558326 |
| antimicrobial activity of feiii, cuii, agi, znii and hgii complexes of 2-(2-hydroxy-5-bromo/nitro-phenyl)-1h- and 2-(2-hydroxyphenyl)-5-methyl/chloro/nitro-1h-benzimidazoles. | antimicrobial activity of 2-(2-hydroxyphenyl)-5-r5-1h-benzimidazoles, 2-(2-hydroxy-5-r5'-phenyl)-1h-benzimidazoles and their feiii, cuii, agi, znii and hgii nitrate complexes was tested toward staphylococcus aureus, staphylococcus epidermidis, escherichia coli, klebsiella pneumoniae, pseudomonas aeruginosa, salmonella typhi, shigella flexneri, and proteus mirabilis. antifungal activity was tested against candida albicans. benzimidazole benzene ring substituents increase the antimicrobial activit ... | 2002 | 12503391 |
| his-asp phosphorelay signal transduction in higher plants: receptors and response regulators for cytokinin signaling in arabidopsis thaliana. | bacteria have devised phosphotransfer signaling mechanisms for eliciting a variety of adaptive responses to their environment. these mechanisms are collectively referred to as two-component regulatory systems. each system generally consists of a sensor protein histidine kinase, which is anchored in the cell membrane, and a cytoplasmic response regulator, whose activity is modulated by the sensor. most response regulators are transcription factors. in this review, we briefly introduce the establi ... | 2002 | 12589073 |
| electrophoretic analysis of salmonella typhi and other bacteria. | a comparative study involving sds-page of salmonella typhi and other bacteria was conducted. protoplasmic antigens of salmonella typhi. salmonella paratyphi a, salmonella typhimurium, proteus sp, klebsiellas sp. pseudomonas aeruginosa, shigella flexneri, staphylococcus aureus were separated and compared on sds-page followed by checking of their cross reactivity by gel diffusion using antisera raised against whole cell and lysates of salmonella typhi. lines of identity between salmonella typhi, s ... | 2002 | 12649947 |
| adipokinetic hormone enhances laminarin and bacterial lipopolysaccharide-induced activation of the prophenoloxidase cascade in the african migratory locust, locusta migratoria. | lom-akh-i enhances the activation in vivo of prophenoloxidase in the haemolymph of the african migratory locust, locusta migratoria, in response to challenge with laminarin. akh does not influence the speed or initial magnitude of the phenoloxidase response to laminarin, but prolongs the period of activation of the enzyme in a dose-dependent manner. injections of preparations of bacterial lipopolysaccharide (lps) do not activate prophenoloxidase in vivo, but co-injection of lom-akh-i with commer ... | 2002 | 12770071 |
| chronic vulvovaginitis caused by antibiotic-resistant shigella flexneri in a prepubertal child. | a 7-year 8-month-old girl was diagnosed with a prolonged course of vulvovaginitis caused by shigella flexneri. the child was symptomatic with intermittent vaginal bleeding, dysuria and foul smelling vaginal discharge for a 3-year period. initial attempts to resolve the infection with successive courses of antibiotic therapy using ampicillin, trimethoprim-sulfamethoxazole, cefixime and amoxicillin/clavulanic acid failed. the child's infection was finally resolved by a 14-day course of ciprofloxac ... | 2002 | 11840089 |
| shigella spa32 is an essential secretory protein for functional type iii secretion machinery and uniformity of its needle length. | the shigella type iii secretion machinery is responsible for delivering to host cells the set of effectors required for invasion. the type iii secretion complex comprises a needle composed of mxih and mxii and a basal body made up of mxid, mxig, and mxij. in s. flexneri, the needle length has a narrow range, with a mean of approximately 45 nm, suggesting that it is strictly regulated. here we show that spa32, encoded by one of the spa genes, is an essential protein translocated via the type iii ... | 2002 | 11844752 |
| cdc42 facilitates invasion but not the actin-based motility of shigella. | the enteric pathogen shigella utilizes host-encoded proteins to invade the gastrointestinal tract. efficient invasion of host cells requires the stimulation of rho-family gtpases and cytoskeletal alterations by shigella-encoded ipac. following invasion and lysis of the phagosome, shigella exploits the host's actin-based polymerization machinery to assemble an actin tail that serves as the propulsive force required for spreading within and between cells. the shigella surface protein icsa stimulat ... | 2002 | 11864577 |
| complete genomic sequence of sfv, a serotype-converting temperate bacteriophage of shigella flexneri. | bacteriophage sfv is a temperate serotype-converting phage of shigella flexneri. sfv encodes the factors involved in type v o-antigen modification, and the serotype conversion and integration-excision modules of the phage have been isolated and characterized. we now report on the complete sequence of the sfv genome (37,074 bp). a total of 53 open reading frames were predicted from the nucleotide sequence, and analysis of the corresponding proteins was used to construct a functional map. the gene ... | 2002 | 11889106 |
| genetic determinants of tetracycline resistance in vibrio harveyi. | isolates of vibrio harveyi, a prawn pathogen, have demonstrated multiple antibiotic resistance to commonly used antimicrobial agents, such as oxytetracycline. in this paper, we describe the cloning and characterization of two tetracycline resistance determinants from v. harveyi strain m3.4l. the first resistance determinant, cloned as a 4,590-bp fragment, was identical to teta and flanking sequences encoded on transposon tn10 from shigella flexneri. the second determinant, cloned as a 3,358-bp f ... | 2002 | 11897587 |
| differential expression of inducible nitric oxide synthase is associated with differential toll-like receptor-4 expression in chicken macrophages from different genetic backgrounds. | the purpose of this study was to examine inos gene expression and activity in macrophages from different chicken genetic lines against various bacterial lps. furthermore, the possible involvement of surface lps receptors as candidates for differential inos gene induction in these genetic lines of chicken was also examined. sephadex-elicited abdominal macrophages (1 x 10(6)) as well as inos hyper-responder macrophages from a transformed chicken macrophage cell line, mq-ncsu, were exposed to 5 mic ... | 2002 | 11777534 |
| antimicrobial and anti-lipase activity of quercetin and its c2-c16 3-o-acyl-esters. | neither quercetin (q), nor 3-o-acylquercetines, up to 100 microg/ml, had any significant activity on selected gram-positive strains (staphylococcus aureus, bacillus subtilis, listeria ivanovi, listeria monocytogenes, listeria serligeri), gram-negative strains (escherichia coli, shigella flexneri, shigella sonnei, salmonella enteritidis, salmonella tiphymurium) and yeasts (candida albicans and candida glabrata). in addition, we confirmed the known anti-hiv activity of q (80% inhibition at 40 micr ... | 2002 | 11741775 |
| in vivo dna-binding and oligomerization properties of the shigella flexneri arac-like transcriptional regulator virf as identified by random and site-specific mutagenesis. | in shigella flexneri expression of the plasmid-encoded virulence genes is regulated via a complex mechanism involving both environmental signals and specific transactivators. the primary regulator protein, virf, is a member of the arac family of transcription factors and shares with other arac-like proteins a conserved carboxy-terminal domain thought to be important for dna binding. random and site-directed mutagenesis of the virf gene encoding virf yielded a number of mutations along the length ... | 2002 | 11751832 |
| polymerase chain reaction detection of invasive shigella and salmonella enterica in food. | 2002 | 11692869 | |
| a method for allelic replacement in francisella tularensis. | a vector for mutagenesis of francisella tularensis was constructed based on the puc19 plasmid. by inserting the sacb gene of bacillus subtilis, orit of plasmid rp4, and a chloramphenicol resistance gene of shigella flexneri, a vector, ppv, was obtained that allowed specific mutagenesis. a protocol was developed that allowed introduction of the vector into the live vaccine strain, lvs, of f. tularensis by conjugation. as a proof of principle, we aimed to develop a specific mutant defective in exp ... | 2003 | 12770718 |
| seasonal variation in bacterial pathogens isolated from stool samples in karachi, pakistan. | to determine the seasonal variation of the commonly isolated bacterial pathogens in stool samples. | 2003 | 12779031 |
| bordetella type iii secretion induces caspase 1-independent necrosis. | the bordetella bronchiseptica type iii (tiii) secretion system induces cytotoxicity in infected macrophages and epithelial cells. in this report we characterize the cell death phenotype and compare it to the tiii-dependent cytotoxicity induced by yersinia enterocolitica and shigella flexneri. bordetella bronchiseptica strain rb58 was able to induce cell death in j774a.1 macrophages with the same efficiency as shigella and yersinia, but only b. bronchiseptica was able to kill epithelial cells in ... | 2003 | 12580948 |
| role of lipid-mediated signal transduction in bacterial internalization. | receptor-mediated phagocytosis normally represents an important first line of immune defence. invading microbes are internalized into phagosomes and are typically killed by exposure to a battery of microbicidal agents. to some intracellular pathogens, however, receptor-mediated phagocytosis represents an opportunity to access a protected niche within the host cell. another type of intracellular pathogen, including salmonella enterica serovar typhimurium and shigella flexneri, invade host cells i ... | 2003 | 12713488 |
| lipopolysaccharide o antigen chains mask icsa (virg) in shigella flexneri. | shigella flexneri 2a strain 2457t lipopolysaccharide (lps) has o antigen (oag) chains with two modal lengths (s-type and vl-type), and has icsa apparently located at one pole on its cell surface. treatment of y serotype derivatives of 2457t and rma696 (2457t wzz(sf)) with sf6 tailspike protein (tsp) resulted in hydrolysis of oag chains, and an increase in detection of icsa by indirect immunofluorescence staining on both the lateral and polar regions of the cell surface. newly synthesised icsa ex ... | 2003 | 12725923 |
| multicopy icsa is able to suppress the virulence defect caused by the wzz(sf) mutation in shigella flexneri. | the lipopolysaccharides (lps) of shigella flexneri are important for virulence and their o antigen (oag) polysaccharide chains affect icsa (virg)-mediated actin-based motility (abm) within mammalian cells. s. flexneri 2a 2457t has smooth lps whose oag chains have two modal lengths (short (s)-type and very long (vl)-type), and has icsa predominantly located at one pole on its cell surface. a s. flexneri 2457t wzz(sf) mutant (rma696) has vl-type oag but not s-type oag chains, less icsa detectable ... | 2003 | 12725929 |
| subunit interaction of monomeric alanine racemases from four shigella species in catalytic reaction. | bacterial alanine racemases are classified into two types of subunit structure (monomer and homodimer). to clarify the catalytic unit of monomeric alanine racemases, we examined the apparent molecular mass of the monomeric alanine racemases from shigella dysenteriae, shigella boydii, shigella flexneri, and shigella sonnei by gel filtration in the presence of the substrate and inhibitor. the enzymes were eluted on gel filtration as a monomer of about 39,000 da at low protein concentration and in ... | 2003 | 12725937 |
| helicobacter pylori: an invading microorganism? a review. | in this review we evaluate the pros and cons of helicobacter pylori invasion of epithelial cells as part of the natural history of h. pylori infection. h. pylori is generally considered an extracellular microorganism. however, a growing body of evidence supports the controversial hypothesis that at least a subset of h. pylori microorganisms has an intracellular (intraepithelial) location. most significant is the fact that h. pylori invades cultured epithelial cells with invasion frequencies simi ... | 2003 | 12738380 |
| icsb, secreted via the type iii secretion system, is chaperoned by ipga and required at the post-invasion stage of shigella pathogenicity. | shigella deliver a subset of effector proteins such as ipaa, ipab and ipac via the type iii secretion system (ttss) into host cells during the infection of colonic epithelial cells. many bacterial effectors including some from shigella require specific chaperones for protection from degradation and targeting to the ttss. in this study, we have investigated the role of the icsb gene located upstream of the ipabcda operon in shigella infection because the role of icsb as a virulence factor remains ... | 2003 | 12753186 |
| shigella flexneri bacteremia in a child. | we report an unusual and lethal case of shigella flexneri septicemia in an 8-year-old saudi handicapped child from a social home presenting with severe toxic megacolon and acute abdomen secondary to fulminant necrotizing enterocolitis. | 2003 | 12754544 |
| patterns and properties of haemagglutinins expressed by shigella serogroups in lagos, nigeria. | forty-five strains of shigella were screened for haemagglutinin production and broad-spectrum haemagglutination reaction. mannose-sensitive haemagglutinin (msha) was found in 22 strains [shigella flexneri (7), s. dysenteriae (7), s. sonnei (3), and s. boydii (5)]. eighteen strains harboured mannose-resistant haemagglutinin (mrha), and 8 strains were observed to be non-haemagglutinating to guinea pig erythrocyte. with the exception of human erythrocytes (o, a, b, and ab), the observed msha and mr ... | 2003 | 13677435 |
| prevalence and pattern of antimicrobial resistance of shigella species among patients with acute diarrhoea in karaj, tehran, iran. | the study was carried out to determine the prevalence and pattern of antimicrobial resistance of shigella species among patients with acute diarrhoea in karaj, tehran, iran. the study included all acute diarrhoea patients who visited the hospitals and treatment centres of karaj during november 2001-october 2002. of 734 stool samples collected from patients with acute diarrhoea and analyzed for shigella spp., 123 (16.8%) yielded shigella spp. (7.5% shigella flexneri, 5.2% s. sonnei, 2.6% s. dysen ... | 2003 | 13677436 |
| expression and purification of invasion plasmid antigen c of shigella flexneri. | to induce the expression of and purify invasion plasmid antigen c (ipac) of shigella flexneri for studying the pathogenesis of shigella flexneri. | 2003 | 12651237 |
| contribution of the shigella flexneri sit, iuc, and feo iron acquisition systems to iron acquisition in vitro and in cultured cells. | shigella flexneri possesses multiple iron acquisition systems, including proteins involved in the synthesis and uptake of siderophores and the feo system for ferrous iron utilization. we identified an additional s. flexneri putative iron transport gene, sita, in a screen for s. flexneri genes that are induced in the eukaryotic intracellular environment. sita was present in all shigella species and in most enteroinvasive escherichia coli strains but not in any other e. coli isolates tested. the s ... | 2003 | 12654809 |
| synthesis and antimicrobial activity of [2-[2-(n, n-disubstituted thiocarbamoyl-sulfanyl)-acylamino] thiazol-4-yl]acetic acid ethyl esters. | [2-[2-(n, n-disubstituted thiocarbamoyl-sulfanyl)acylamino ]thiazol-4-yl]acetic acid ethyl esters (3a-x) were synthesized by the reaction of potassium salts of n, n-disubstituted dithiocarbamoic acids with [2-(2-chloroalkanoyl)amino-thiazol-4-yl]acetic acid ethyl esters. the structures of the synthesized compounds were confirmed by elemental analyses, uv, ir, (1)h-nmr, and ei mass spectral data. the antimicrobial activities of all the compounds were investigated by microbroth dilution technique ... | 2003 | 12666252 |
| genetic modulation of shigella flexneri 2a lipopolysaccharide o antigen modal chain length reveals that it has been optimized for virulence. | the lipopolysaccharide (lps) molecules of shigella flexneri 2a have o antigen (oag) polysaccharides with two modal chain length distributions. the chromosomal wzz(sf) gene results in short (s) type oag chains [11-17 oag repeat units (rus)], and the phs-2 plasmid-located wzz(phs2) gene results in very long (vl) type oag chains (>90 oag rus). s. flexneri wzz(sf) mutants are unable to form plaques on hela cell monolayers and f-actin comet tails, indicating that icsa/virg function in actin-based mot ... | 2003 | 12686635 |
| attenuated salmonella enterica serovar typhi and shigella flexneri 2a strains mucosally deliver dna vaccines encoding measles virus hemagglutinin, inducing specific immune responses and protection in cotton rats. | measles remains a leading cause of child mortality in developing countries. residual maternal measles antibodies and immunologic immaturity dampen immunogenicity of the current vaccine in young infants. because cotton rat respiratory tract is susceptible to measles virus (mv) replication after intranasal (i.n.) challenge, this model can be used to assess the efficacy of mv vaccines. pursuing a new measles vaccine strategy that might be effective in young infants, we used attenuated salmonella en ... | 2003 | 12692223 |
| antimicrobial effect of spices and herbs on shigella sonnei and shigella flexneri. | of 17 spices and herbs tested at 1% (wt/vol) in mueller-hinton (mh) agar, only cloves, thyme, oregano, allspice, basil, rosemary, and marjoram showed antimicrobial effects on shigella. the mics of thyme, oregano, basil, and rosemary (as determined by the agar dilution method) ranged from 0.5 to 1% (wt/vol) depending on the shigella strain used. with the use of various combinations of temperatures (12, 22, and 37 degrees c), phs (5.0, 5.5, and 6.0), and nacl concentrations (1, 2, 3, and 4%, wt/vo ... | 2003 | 12696694 |
| complete genome sequence and comparative genomics of shigella flexneri serotype 2a strain 2457t. | we determined the complete genome sequence of shigella flexneri serotype 2a strain 2457t (4,599,354 bp). shigella species cause >1 million deaths per year from dysentery and diarrhea and have a lifestyle that is markedly different from those of closely related bacteria, including escherichia coli. the genome exhibits the backbone and island mosaic structure of e. coli pathogens, albeit with much less horizontally transferred dna and lacking 357 genes present in e. coli. the strain is distinctive ... | 2003 | 12704152 |
| morphology of temperate bacteriophage sfv and characterisation of the dna packaging and capsid genes: the structural genes evolved from two different phage families. | the entire genome of sfv, a temperate serotype-converting bacteriophage of shigella flexneri, has recently been sequenced (allison, g.e., angeles, d., tran-dinh, n., verma, n.k. 2002, j. bacteriol. 184, 1974-1987). based on the sequence analysis, we further characterised the sfv virion structure and morphogenesis. electron microscopy indicated that sfv belongs to the myoviridae morphology family. analysis of the proteins encoded by orf1, orf2, and orf3 revealed that they were homologous to small ... | 2003 | 12706095 |
| a novel modeling protocol for protein receptors guided by bound-ligand conformation. | a novel protocol for protein homology modeling is described, in which uncertainty in protein structure is resolved by applying the criterion that the protein must bind to a complementary ligand. a diverse library of protein models is created and then screened by docking with ligands of known conformation. the more accurate protein models form higher-quality docked complexes, and the quality of the fit is used to select the best models. the effectiveness of this technique with both natural and un ... | 2003 | 12590571 |
| structural characterization of the n terminus of ipac from shigella flexneri. | the primary effector for shigella invasion of epithelial cells is ipac, which is secreted via a type iii secretion system. we recently reported that the ipac n terminus is required for type iii secretion and possibly other functions. in this study, mutagenesis was used to identify an n-terminal secretion signal and to determine the functional importance of the rest of the ipac n terminus. the 15 n-terminal amino acids target ipac for secretion by shigella flexneri, and placing additional amino a ... | 2003 | 12595440 |
| genetic characterization and immunogenicity of coli surface antigen 4 from enterotoxigenic escherichia coli when it is expressed in a shigella live-vector strain. | the genes that encode the enterotoxigenic escherichia coli (etec) cs4 fimbriae, csaa, -b, -c, -e, and -d', were isolated from strain e11881a. the csa operon encodes a 17-kda major fimbrial subunit (csab), a 40-kda tip-associated protein (csae), a 27-kda chaperone-like protein (csaa), a 97-kda usher-like protein (csac), and a deleted regulatory protein (csad'). the predicted amino acid sequences of the cs4 proteins are highly homologous to structural and assembly proteins of other etec fimbriae, ... | 2003 | 12595452 |
| effects of ectopically expressed neuronal wiskott-aldrich syndrome protein domains on rickettsia rickettsii actin-based motility. | neuronal wiskott-aldrich syndrome protein (n-wasp) and the actin-related protein 2/3 (arp2/3) complex have emerged as critical host proteins that regulate pathogen actin-based motility. actin tail formation and motility in listeria monocytogenes require the arp2/3 complex but bypasses n-wasp signaling. motility of shigella flexneri and vaccinia virus requires both n-wasp and the arp2/3 complex. functional roles for these cytoskeletal regulatory proteins in actin-based motility of rickettsia rick ... | 2003 | 12595475 |
| regulation of salmonella typhimurium lipopolysaccharide o antigen chain length is required for virulence; identification of fepe as a second wzz. | wzz proteins regulate the degree of polymerization of the o antigen (oag) subunits in lipopolysaccharide (lps) biosynthesis. although the pathogenic relevance of oag is well recognized, the significance of oag chain length regulation is not well defined. in this report, salmonella typhimurium was shown to possess two functional wzz genes resulting in a bimodal oag length distribution. in addition to the previously described wzzst that results in long (l) modal length lps with 16-35 oag repeat un ... | 2003 | 12603743 |
| in vitro susceptibilities of shigella flexneri and streptococcus pyogenes to inner gel of aloe barbadensis miller. | aloe barbadensis miller (or aloe vera) has widespread use in health products, and despite numerous reports on the whole plant, little work has been performed on the inner gel, which has been used extensively in these products. this report describes the in vitro susceptibilities of two bacteria to this component. | 2003 | 12604556 |
| enhancer-promoter communication mediated by chip during pannier-driven proneural patterning is regulated by osa. | the gata factor pannier activates proneural achaete/scute (ac/sc) expression during development of the sensory organs of drosophila through enhancer binding. chip bridges pannier with the (ac/sc)-daughterless heterodimers bound to the promoter and facilitates the enhancer-promoter communication required for proneural development. we show here that this communication is regulated by osa, which is recruited by pannier and chip. osa belongs to brahma chromatin remodeling complexes and we show that ... | 2003 | 12629041 |
| comparison of antimicrobial susceptibility between invasive and non-invasive shigella organisms. | antimicrobial susceptibility was determined for ten strains of shigella spp. comparing invasive (invasion plasmid containing) and non-invasive members of each strain. the activity of the antimicrobial agents could be classified into three types from the differences between the minimum inhibitory concentration (mic) for the invasive and non-invasive shigellae. for type 1, there was no difference between the mic (an mic gap) for invasive and non-invasive organisms. for type 2, the mic for the inva ... | 2003 | 12636989 |
| virtual screening for submicromolar leads of trna-guanine transglycosylase based on a new unexpected binding mode detected by crystal structure analysis. | eubacterial trna-guanine transglycosylase (tgt) is involved in the hypermodification of cognate trnas, leading to the exchange of g34 by preq1 at the wobble position in the anticodon loop. mutation of the tgt gene in shigella flexneri results in a significant loss of pathogenicity of the bacterium due to inefficient translation of a virulence protein mrna. herein, we describe the discovery of a ligand with an unexpected binding mode. on the basis of this binding mode, three slightly deviating ph ... | 2003 | 12646024 |
| human lactoferrin impairs virulence of shigella flexneri. | lactoferrin is a glycoprotein present in most human mucosal secretions, including human milk. lactoferrin is bacteriostatic in low iron media and, in some settings, bactericidal. lactoferrin impairs ability of shigella flexneri serotype 5 strain m90t to invade hela cells. to determine the mechanism by which lactoferrin decreases invasiveness of shigella organisms, its effect on the major virulence proteins responsible for bacterial uptake by host cells was evaluated. lactoferrin induced degradat ... | 2003 | 12508150 |
| sporadic enteric reactive arthritis and undifferentiated spondyloarthropathy: evidence for involvement of salmonella typhimurium. | to define the candidate bacterial trigger and cytokine profile of synovial fluid mononuclear cells (sfmc) in patients with sporadic enteric reactive arthritis (rea) and undifferentiated spondyloarthropathy (uspa). | 2003 | 12508398 |
| phenotypic and genotypic characterization of provisional serotype shigella flexneri 1c and clonal relationships with 1a and 1b strains isolated in bangladesh. | the serotypes of 144 strains of shigella flexneri serotype 1 (serotypes 1a, 1b, and 1c) isolated from patients attending the dhaka treatment center of the international centre for diarrhoeal disease research, bangladesh, between 1997 and 2001 were serologically confirmed by using commercially available antisera and a panel of monoclonal antibodies specific for s. flexneri group and type factor antigen (masf). among serotype 1 isolates, the prevalence of provisional serotype s. flexneri 1c increa ... | 2003 | 12517835 |
| [simultaneous expression of cs3 colonization factor antigen and lt-b/st fusion enterotoxin antigen of enterotoxigenic escherichia coli by attenuated shigella flexneri 2a]. | enterotoxigenic escherichia coli (etec) causes watery dehydrating diarrhea in infants in developing countries, and is the most common cause of travelers diarrhea. it has been known that the colonazition factor antigens (cfas) and enterotoxins are important virulence factors of etec, and these two kinds of proteins should be included in any effective vaccine against etec. in this study, a host-plasmid lethal balancing system was constructed based on asd gene in an avirulent strain of s.flexneri ... | 2003 | 12518227 |
| putrescine or a combination of methionine and arginine restores virulence gene expression in a trna modification-deficient mutant of shigella flexneri: a possible role in adaptation of virulence. | the wild-type strain ysh6000 of shigella flexneri growing in minimal medium contains the modified nucleoside epoxy-q (oq) in a subset of trnas. this nucleoside is lacking in trna from a tgt mutant of this bacterium. when these bacteria are growing in minimal medium, the expression of virulence genes is 10-fold lower in the tgt mutant than in the wild type, although only a twofold reduction in the expression of these virulence factors is observed in broth. such a strong media-dependant expression ... | 2003 | 12519201 |
| the magnificent seven. | 2003 | 12526849 | |
| nod2 is a general sensor of peptidoglycan through muramyl dipeptide (mdp) detection. | nod2 activates the nf-kappab pathway following intracellular stimulation by bacterial products. recently, mutations in nod2 have been shown to be associated with crohn's disease, suggesting a role for bacteria-host interactions in the etiology of this disorder. we show here that nod2 is a general sensor of peptidoglycan through the recognition of muramyl dipeptide (mdp), the minimal bioactive peptidoglycan motif common to all bacteria. moreover, the 3020insc frameshift mutation, the most frequen ... | 2003 | 12527755 |
| immunogenicity of an hiv-1 gag dna vaccine carried by attenuated shigella. | the use of live attenuated invasive bacteria as a carrier for dna-based vaccines has been reported recently. in this study, we used a shigella flexneri serotype 2a rfbf mutant for immunization of a dna vaccine coding for hiv-1 sf2 gag. the recombinant bacterial vector delivered gag dna to mammalian cells in vitro resulting in gag protein expression, and was found to have a low level of pathogenicity among a number of shigella cell spread defective mutants tested. intranasal immunization of mice ... | 2003 | 12531333 |
| an extended role for the nucleoid structuring protein h-ns in the virulence gene regulatory cascade of shigella flexneri. | the h-ns nucleoid structuring protein has been shown previously to play a negative role in controlling virulence gene expression in shigella flexneri by repressing transcription of the virf and virb regulatory genes and the virf-dependent icsa structural gene under non-permissive growth conditions. here, we show that h-ns also acts at the promoters of the virb-dependent structural genes in the regulatory cascade. h-ns protein binds to the promoter regions in vivo and in vitro. the promoters were ... | 2003 | 12535079 |