Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| mitogenic response and probiotic characteristics of lactic acid bacteria isolated from indigenously pickled vegetables and fermented beverages. | lactic acid bacteria from indigenous pickled vegetables and fermented beverages (fermented rice and madhuca longifolia flowers) were isolated and investigated for their functional characteristics in vitro as potential new probiotic strains. four isolates (all lactobacillus spp.) selected on the basis of high tolerance to bile (0.2%) were identified by standard and molecular methods (16s rdna) as l. helveticus, l. casei, l. delbrueckii and l. bulgaricus from pickled vegetables and fermented bever ... | 2011 | 22806866 |
| analysis of synonymous codon usage in shigella flexneri 2a strain 301 and other shigella and escherichia coli strains. | in this study, we analysed synonymous codon usage in shigella flexneri 2a strain 301 (sf301) and performed a comparative analysis of synonymous codon usage patterns in sf301 and other strains of shigella and escherichia coli. although there was a significant variety in codon usage bias among different sf301 genes, there was a slight but observable codon usage bias that could primarily be attributable to mutational pressure and translational selection. in addition, the relative abundance of dinuc ... | 2011 | 22112197 |
| a proteogenomic analysis of shigella flexneri using 2d lc-maldi tof/tof. | new strategies for high-throughput sequencing are constantly appearing, leading to a great increase in the number of completely sequenced genomes. unfortunately, computational genome annotation is out of step with this progress. thus, the accurate annotation of these genomes has become a bottleneck of knowledge acquisition. | 2011 | 22032405 |
| contribution of the lipopolysaccharide to resistance of shigella flexneri 2a to extreme acidity. | shigella flexneri is endemic in most underdeveloped countries, causing diarrheal disease and dysentery among young children. in order to reach its target site, the colon, shigella must overcome the acid environment of the stomach. shigella is able to persist in this stressful environment and, because of this ability it can initiate infection following the ingestion of very small inocula. thus, acid resistance is considered an important virulence trait of this bacterium. it has been reported that ... | 2011 | 21984920 |
| a 35 kda antigenic protein from shigella flexneri: in silico structural and functional studies. | shigella flexneri serotype 2a is a major public health concern in the developing and under-developed countries which contributes to shigellosis endemic and mortality. thus, there is an urgent need for a rapid diagnostic test for effective therapy and disease management. previous study showed that a ∼35 kda antigenic protein from s. flexneri is a potential biomarker. we therefore modelled the three-dimensional structure of the antigen to probe its functionality which could aid in the development ... | 2011 | 21982766 |
| outer membrane protein a (ompa) of shigella flexneri 2a, induces protective immune response in a mouse model. | in our earlier studies 34 kda outer membrane protein (omp) of shigella flexneri 2a has been identified as an efficient immunostimulant. | 2011 | 21818362 |
| safety, and immunogenicity of an intranasal shigella flexneri 2a invaplex 50 vaccine. | background: shigella flexneri 2a invaplex 50 is a nasally delivered subunit vaccine consisting of a macromolecular complex composed of lps, ipab, ipac and ipad. the current study examined vaccine safety and immunogenicity across a dose range and the clinical performance of a new intranasal delivery device. methods: volunteers (n=36) were randomized to receive vaccine via the dolphin™ (valois of america, congers, new york) intranasal spray device at one of three doses (240, 480, and 690µg) on day ... | 2011 | 21787825 |
| serine protease autotransporters from shigella flexneri and pathogenic escherichia coli target a broad range of leukocyte glycoproteins. | the serine protease autotransporters of enterobacteriaceae (spates) are secreted by pathogenic gram-negative bacteria through the autotransporter pathway. we previously classified spate proteins into two classes: cytotoxic (class 1) and noncytotoxic (class 2). here, we show that pic, a class 2 spate protein produced by shigella flexneri 2a, uropathogenic and enteroaggregative escherichia coli strains, targets a broad range of human leukocyte adhesion proteins. substrate specificity was restricte ... | 2011 | 21768350 |
| dynamic aspects of antibody:oligosaccharide complexes characterized by molecular dynamics simulations and std-nmr. | carbohydrates are likely to maintain significant conformational flexibility in antibody:carbohydrate complexes. as demonstrated herein for the protective monoclonal antibody f22-4 recognizing the shigella flexneri 2a o-antigen and numerous synthetic oligosaccharide fragments thereof, the combination of molecular dynamics simulations and nmr saturation transfer difference experiments, supported by physicochemical analysis, allows to determine the binding epitope and its various contributions to a ... | 2011 | 21610193 |
| antigen-specific iga b memory cell responses to shigella antigens elicited in volunteers immunized with live attenuated shigella flexneri 2a oral vaccine candidates. | we studied the induction of antigen-specific iga memory b cells (b(m)) in volunteers who received live attenuated shigella flexneri 2a vaccines. subjects ingested a single oral dose of 10(7), 10(8) or 10(9) cfu of s. flexneri 2a with deletions in guaba (cvd 1204) or in guaba, set and sen (cvd 1208). antigen-specific serum and stool antibody responses to lps and ipa b were measured on days 0, 7, 14, 28 and 42. iga b(m) cells specific to lps, ipa b and total iga were assessed on days 0 and 28. we ... | 2011 | 21388888 |
| shigella enterotoxin-2 is a type iii effector that participates in shigella-induced interleukin 8 secretion by epithelial cells. | we have previously described a protein termed shigella enterotoxin 2 (shet-2), which induces rises in short-circuit current in rabbit ileum mounted in the ussing chamber. published reports have postulated that shet-2 may be secreted by the shigella type iii secretion system (t3ss). in this study, we show that shet-2 secretion into the extracellular space requires the t3ss in shigella flexneri 2a strain 2457t and a shet-2-tem fusion was translocated into epithelial cells in a t3ss-dependent manne ... | 2011 | 21219446 |
| notes from the field: emergence of shigella flexneri 2a resistant to ceftriaxone and ciprofloxacin --- south carolina, october 2010. | on october 20, 2010, the south carolina department of health and environmental control and cdc began investigating a cluster of three diarrheal illnesses caused by multidrug-resistant shigella flexneri 2a. the index case occurred in a girl aged 2 years who experienced the onset of diarrhea on september 25 and was hospitalized the next day because of a seizure and fever. on september 30, her brother, aged 6 years, was hospitalized with vomiting, bloody diarrhea, and hyponatremia. three days later ... | 2010 | 21160457 |
| safety, dose, immunogenicity, and transmissibility of an oral live attenuated shigella flexneri 2a vaccine candidate (sc602) among healthy adults and school children in matlab, bangladesh. | in double-blind trials in bangladesh, 88 adults, and 79 children (8-10 years) were randomized to receive either a single oral dose of 1 × 10(4), 1 × 10(5) or 1 × 10(6)cfu of sc602 (a live, attenuated shigella flexneri 2a strain vaccine) or placebo. in the adult outpatient 1 × 10(6) cfu group, severe joint pain and body aches were reported by one and two vaccinees respectively. in the adult inpatient trial, sc602 was isolated from 3 volunteers, pre-vaccination antibody titers were high, and fourf ... | 2010 | 21040694 |
| safety and immunogenicity of a shigella flexneri 2a invaplex 50 intranasal vaccine in adult volunteers. | shigellosis is a leading cause of diarrhea worldwide prompting vaccine development. the shigella flexneri invaplex 50 is a macromolecular complex containing ipab, ipac, and lps, formulated from an aqueous extract of virulent shigella delivered via nasal administration. preclinical vaccine testing demonstrated safety, immunogenicity and efficacy. an open-label dose-escalating phase 1 study evaluated a 3-dose (2-week intervals) regimen via nasal pipette delivery. thirty-two subjects were enrolled ... | 2010 | 20619378 |
| immunochemical studies of shigella flexneri 2a and 6, and shigella dysenteriae type 1 o-specific polysaccharide-core fragments and their protein conjugates as vaccine candidates. | there is no licensed vaccine for the prevention of shigellosis. our approach to the development of a shigella vaccines is based on inducing serum igg antibodies to the o-specific polysaccharide (o-sp) domain of their lipopolysaccharides (lps). we have shown that low molecular mass o-sp-core (o-spc) fragments isolated from shigella sonnei lps conjugated to proteins induced significantly higher antibody levels in mice than the full length o-sp conjugates. this finding is now extended to the o-spc ... | 2010 | 20542498 |
| a novel anti-virulence gene revealed by proteomic analysis in shigella flexneri 2a. | abstract: | 2010 | 20540790 |
| genome-wide analysis of the h-ns and sfh regulatory networks in salmonella typhimurium identifies a plasmid-encoded transcription silencing mechanism. | the conjugative inchi1 plasmid psfr27 from shigella flexneri 2a strain 2457t encodes the sfh protein, a paralogue of the global transcriptional repressor h-ns. sfh allows psfr27 to be transmitted to new bacterial hosts with minimal impact on host fitness, providing a 'stealth' function whose molecular mechanism has yet to be determined. the impact of the sfh protein on the salmonella enterica serovar typhimurium transcriptome was assessed and binding sites for sfh in the salmonella typhimurium g ... | 2010 | 20444106 |
| 34 kda momp of shigella flexneri promotes tlr2 mediated macrophage activation with the engagement of nf-kappab and p38 map kinase signaling. | the 34 kda major outer membrane protein (momp) of shigella flexneri 2a induces combinatorial expression of tlr2 and tlr6 on peritoneal macrophages of balb/c mice. between the two best-characterized tlrs, to date, tlr2 and tlr4, which are chiefly responsible for recognizing majority of bacterial products, tlr2 alone participates in recognition of 34 kda momp. in addition to tlrs, momp enhances the mrna expression of myd88 and traf6 and induces the nuclear translocation of nf-kappab as well as act ... | 2010 | 20347487 |
| an urban, water-borne outbreak of diarrhoea and shigellosis in a district town in eastern india. | in september 2007, the gayeshpur municipality reported a cluster of cases with diarrhoea. we aimed to identify the causative agent and the source of the disease. | 2009 | 20334044 |
| the proteome of shigella flexneri 2a 2457t grown at 30 and 37 degrees c. | to upgrade the proteome reference map of shigella flexneri 2a 2457t, the protein expression profiles of log phase and stationary phase cells grown at 30 and 37 degrees c were thoroughly analyzed using multiple overlapping narrow ph range (between ph 4.0 and 11.0) two-dimensional gel electrophoresis. a total of 723 spots representing 574 protein entries were identified by maldi-tof/tof ms, including the majority of known key virulence factors. 64 hypothetical proteins and six misannotated protein ... | 2010 | 20164057 |
| age-related efficacy of shigella o-specific polysaccharide conjugates in 1-4-year-old israeli children. | despite its high worldwide morbidity and mortality, there is yet no licensed vaccine for shigellosis. we reported the safety and immunogenicity of shigella o-specific polysaccharide-protein conjugates in adults and young children and efficacy of shigella sonnei conjugate in young adults. | 2010 | 20056180 |
| the immunogenic siga enterotoxin of shigella flexneri 2a binds to hep-2 cells and induces fodrin redistribution in intoxicated epithelial cells. | we have previously shown that the enterotoxin siga which resides on the she pathogenicity island (pai) of s. flexneri 2a is an autonomously secreted serine protease capable of degrading casein. we have also demonstrated that siga is cytopathic for hep-2 cells and plays a role in the intestinal fluid accumulation associated with s. flexneri infections. | 2009 | 20011051 |
| emergence of a new multidrug-resistant serotype x variant in an epidemic clone of shigella flexneri. | shigella spp. are the causative agent of shigellosis with shigella flexneri serotype 2a being the most prevalent in developing countries. epidemiological surveillance in china found that a new serotype of s. flexneri appeared in 2001 and replaced serotype 2a in 2003 as the most prevalent serotype in henan province. the new serotype also became the dominant serotype in 7 of the 10 other provinces under surveillance in china by 2007. the serotype was identified as a variant of serotype x. it diffe ... | 2010 | 19955273 |
| characterization of wrss2 and wrss3, new second-generation virg(icsa)-based shigella sonnei vaccine candidates with the potential for reduced reactogenicity. | live, attenuated shigella vaccine candidates, such as shigella sonnei strain wrss1, shigella flexneri 2a strain sc602, and shigella dysenteriae 1 strain wrsd1, are attenuated principally by the loss of the virg(icsa) protein. these candidates have proven to be safe and immunogenic in volunteer trials and in one study, efficacious against shigellosis. one drawback of these candidate vaccines has been the reactogenic symptoms of fever and diarrhea experienced by the volunteers, that increased in a ... | 2010 | 19932216 |
| virulence, inflammatory potential, and adaptive immunity induced by shigella flexneri msbb mutants. | the ability of genetically detoxified lipopolysaccharide (lps) to stimulate adaptive immune responses is an ongoing area of investigation with significant consequences for the development of safe and effective bacterial vaccines and adjuvants. one approach to genetic detoxification is the deletion of genes whose products modify lps. the msbb1 and msbb2 genes, which encode late acyltransferases, were deleted in the shigella flexneri 2a human challenge strain 2457t to evaluate the virulence, infla ... | 2010 | 19884336 |
| protective role of mouse mbl-c on intestinal mucosa during shigella flexneri invasion. | mannan-binding lectin (mbl) is a c-type serum lectin, which is believed to play an important role in the innate immunity against a variety of pathogens. mbl can bind to sugar determinants of a wide variety of microorganisms, neutralize them and inhibit infection by complement activation through the lectin pathway and opsonization by collectin receptors. given that small intestine is a predominant site of extrahepatic expression of mbl, here we addressed the question whether mbl is involved in mu ... | 2009 | 19684159 |
| purification and characterization of an immunogenic outer membrane protein of shigella flexneri 2a. | in the present study we purified 34 kda major outer membrane protein (momp) of shigella flexneri 2a for the first time, which was cross-reactive and antigenically conserved among shigella spp. and the epitope was surface exposed on the intact bacterium. the purified antigen was found to be glycosylated, which aids in binding to macrophages and up-regulated the production of nitric oxide, granulocyte-colony stimulating factor and il-12p70, indicating that the momp is immunogenic and has the abili ... | 2009 | 19660587 |
| rational design and immunogenicity of liposome-based diepitope constructs: application to synthetic oligosaccharides mimicking the shigella flexneri 2a o-antigen. | we have designed chemically defined diepitope constructs consisting of liposomes displaying at their surface synthetic oligosaccharides mimicking the o-antigen of the shigella flexneri 2a lipopolysaccharide (b-cell epitope) and influenza hemagglutinin peptide ha 307-319 (th epitope). using well controlled and high-yielding covalent bioconjugation reactions, the two structurally independent epitopes were coupled to the lipopeptide pam(3)cag, i.e. a tlr2 ligand known for its adjuvant properties, a ... | 2009 | 19559116 |
| the cellular level of o-antigen polymerase wzy determines chain length regulation by wzzb and wzzphs-2 in shigella flexneri 2a. | the lipopolysaccharide o antigen of shigella flexneri 2a has two preferred chain lengths, a short (s-oag) composed of an average of 17 repeated units and a very long (vl-oag) of about 90 repeated units. these chain length distributions are controlled by the chromosomally encoded wzzb and the plasmid-encoded wzz(phs-2) proteins, respectively. in this study, genes wzzb, wzz(phs-2) and wzy (encoding the o-antigen polymerase) were cloned under the control of arabinose- and rhamnose-inducible promote ... | 2009 | 19556292 |
| complete dna sequence and gene analysis of the virulence plasmid pcp301 of shigella flexneri 2a. | the complete nucleotide sequence and organization of the large virulence plasmid pcp301 (termed by us) of shigella flexneri 2a strain 301 were determined and analyzed. the result showed that the entire dna sequence of pcp301 is composed of 221618 bp which form a circular plasmid. sequence analysis identified 272 open reading frames (orfs), among which, 194 correspond to the proteins described previously, 61 have low identity (<60%) to known proteins and the rest 17 have no regions of significant ... | 2003 | 19448991 |
| structural mimicry of o-antigen by a peptide revealed in a complex with an antibody raised against shigella flexneri serotype 2a. | the use of carbohydrate-mimicking peptides to induce immune responses against surface polysaccharides of pathogenic bacteria offers a novel approach to vaccine development. factors governing antigenic and immunogenic mimicry, however, are complex and poorly understood. we have addressed this question using the anti-lipopolysaccharide monoclonal antibody f22-4, which was raised against shigella flexneri serotype 2a and shown to protect against homologous infection in a mouse model. in a previous ... | 2009 | 19328810 |
| a synthetic carbohydrate-protein conjugate vaccine candidate against shigella flexneri 2a infection. | the protective ag of shigella, the gram-negative enteroinvasive bacterium causing bacillary dysentery, or shigellosis, is its o-specific polysaccharide (o-sp) domain of the lps, the major bacterial surface component. as an alternative to the development of detoxified lps-based conjugate vaccines, recent effort was put into the investigation of neoglycoproteins encompassing synthetic oligosaccharides mimicking the protective ags of the o-sp. we previously reported that when coupled to tetanus tox ... | 2009 | 19201878 |
| short report: high prevalence of serine protease autotransporter cytotoxins among strains of enteroaggregative escherichia coli. | enteroaggregative escherichia coli (eaec) pathogenesis is thought to comprise intestinal colonization followed by the release of enterotoxins and cytotoxins. here, we use a polymerase chain reaction (pcr) to determine the prevalence of 10 genes encoding serine protease autotransporter toxins (spates) in a collection of clinical eaec isolates. eighty-six percent of eaec strains harbored genes encoding one or more class i cytotoxic spate proteins (pet, sat, espp, or siga). two class ii, non-cytoto ... | 2009 | 19190229 |
| overexpression, purification, characterization and preliminary crystallographic study of phosphoglycolate phosphatase from shigella flexneri 2a strain 301. | phosphoglycolate phosphatase has a salvage function in the metabolism of the 2-phosphoglycolate formed during bacterial dna repair. in order to better understand its dimerization behaviour, the influence of metal ions on its activity and its catalytic mechanism at the molecular level, recombinant phosphoglycolate phosphatase from shigella flexneri was overexpressed, purified, characterized and crystallized by the hanging-drop vapour-diffusion method at 291 k using polyethylene glycol 3500 as a p ... | 2009 | 19153451 |
| in silico comparison of simple sequence repeats in high nucleotides-rich genomes of microorganism. | this study determined the distribution of a specific group of simple sequence repeats (ssrs), in genome sequences of 7 chromosomes (shigella flexneri 2a str 301 and 2457 t, shigella sonnei, e. coli k12, m. tuberculosis, m. leprae and s. saprophytycus) have downloaded from the genbank database for identifying abundance, distribution and composition of ssrs. the data obtained in the present study show that: (i) tandem repeats are widely distributed throughout the genomes. (ii) ssrs are differentia ... | 2008 | 19137845 |
| antigen-specific b memory cell responses to lipopolysaccharide (lps) and invasion plasmid antigen (ipa) b elicited in volunteers vaccinated with live-attenuated shigella flexneri 2a vaccine candidates. | we evaluated b memory responses in healthy adult volunteers who received one oral dose of live-attenuated shigella flexneri 2a vaccine. lps-specific b(m) cells increased from a median of 0 at baseline to 20 spot forming cells (sfc)/10(6) expanded cells following vaccination (p=0.008). a strong correlation was found between post-vaccination anti-lps b(m) cell counts and peak serum anti-lps igg titers (rs=0.95, p=0.0003). increases in b(m) specific for ipab approaching significance were also obser ... | 2009 | 19022324 |
| analysis of immune responses and serological cross reactivities among vibrio cholerae o1, shigella flexneri 2a and haemophilus influenzae b. | antigenic determinants expressed on the bacterial cell surface are of importance in the serological characterization and microbiological diagnosis. the bacterial strains carrying these identical or similar antigenic epitopes might react with antibodies produced against other strains. in this study, strong immunogenicity and antigenic cross reactivity were demonstrated among v. cholerae o1, s. flexnerii 2a and h. influenzae b surface components. the enzyme linked immunosorbent assay (elisa) resul ... | 2008 | 18954564 |
| [htpg protein of shigella flexneri 2a strain 2457t evokes inflammatory response in mice]. | to analyze the function of htpg of s. flexneri 2a 2457t, we constructed an htpg deletion mutant and a recovery mutant. | 2008 | 18837368 |
| construction of a trivalent candidate vaccine against shigella species with dna recombination. | in this work asd gene of shigella flexneri 2a strain t32 was replaced by vibrio cholerae toxin b subunit (ctxb) gene with dna recombination in vivo and in vitro. the resulting derivative of t32, designed as fwl01, could stably express ctxb, but its growth in lb medium depended on the presence of diaminopimelic acid (dap). then form i plasmid of shigella sonnei strain s7 was labeled with strain t32 asd gene and mobilized into fwl01. thus a trivalent candidate oral vaccine strain, designed as fsw0 ... | 2002 | 18763059 |
| use of mchi encoding immunity to the antimicrobial peptide microcin h47 as a plasmid selection marker in attenuated bacterial live vectors. | live attenuated bacterial strains expressing heterologous antigens represent an attractive vaccine development strategy. however, the use of drug resistance genes for the selection of expression plasmids introduced into live vectors poses theoretical health risks. therefore, we developed a novel approach for plasmid selection based on immunity to the antimicrobial peptide microcin h47 (mcch47). two expression plasmids encoding the reporter green fluorescent protein (gfpuv) were constructed; sele ... | 2008 | 18663003 |
| structures of synthetic o-antigen fragments from serotype 2a shigella flexneri in complex with a protective monoclonal antibody. | the anti-lps igg mab f22-4, raised against shigella flexneri serotype 2a bacteria, protects against homologous, but not heterologous, challenge in an experimental animal model. we report the crystal structures of complexes formed between fab f22-4 and two synthetic oligosaccharides, a decasaccharide and a pentadecasaccharide that were previously shown to be both immunogenic and antigenic mimics of the s. flexneri serotype 2a o-antigen. f22-4 binds to an epitope contained within two consecutive 2 ... | 2008 | 18621718 |
| simple sequence repeats in different genome sequences of shigella and comparison with high gc and at-rich genomes. | simple sequence repeats (ssrs) are omnipresent in prokaryotes and eukaryotes, and are found anywhere in the genome in both protein encoding and noncoding regions. in present study the whole genome sequences of seven chromosomes (shigella flexneri 2a str301 and 2457t, shigella sonnei, escherichia coli k12, mycobacterium tuberculosis, mycobacterium leprae and staphylococcus saprophyticus) have downloaded from the genbank database for identifying abundance, distribution and composition of ssrs and ... | 2008 | 18464038 |
| immunogenicity and efficacy of highly purified invasin complex vaccine from shigella flexneri 2a. | development of a subunit vaccine for shigellosis requires identification of protective antigens and delivering these antigens in a manner that stimulates immunity comparable to that induced by natural infection. the shigella invasin complex (invaplex) vaccine is an ion-exchange-purified extract from virulent shigella that consists of lps and several other proteins, including the invasins ipab and ipac. intranasal delivery of invaplex stimulates protective immunity in small animal models for shig ... | 2008 | 18276045 |
| differential activation of human tlr4 by escherichia coli and shigella flexneri 2a lipopolysaccharide: combined effects of lipid a acylation state and tlr4 polymorphisms on signaling. | the lipid a of lps activates tlr4 through an interaction with myeloid differentiation protein-2 (md-2) and the degree of lipid a acylation affects tlr4 responsiveness. two tlr4 single nucleotide polymorphisms (asp299gly and thr399ile) have been associated with lps hyporesponsiveness. we hypothesized that the combination of hypoacylation and these single nucleotide polymorphisms would exhibit a compounded effect on tlr4 signaling. hek293t transfectants expressing wild-type or polymorphic tlr4 wer ... | 2008 | 18178854 |
| [expression profile analysis of host hela cells invasived by shigella flexneri 2a]. | the changes of genes expression in hela cell during the invasion with shigella species for 1h and 3h were analyzed by cdna microarrays. the data showed that the expression levels of 752 genes were altered twice or greater as compared with the control 509 of them were up-regulated, and 306 were down-regulated. it was supposed that some signal pathways in hela cell were activated, then many genes were induced, and at last comprehensive cell responses were produced, so that hela cell could prevent ... | 2007 | 18062254 |
| cloning, expression, purification, characterization, crystallization and x-ray diffraction of bifunctional pyrimidine deaminase/reductase from shigella flexneri 2a. | bifunctional pyrimidine deaminase/reductase (ribd) plays an important role during riboflavin biosynthesis in many microorganisms. the 40.4 kda ribd from shigella flexneri 2a has been cloned, expressed, purified and characterized. three crystals of ribd have been obtained by the hanging-drop technique at 291 k using peg 20k or nacl as precipitant. the ribd crystal using peg 20k as precipitant diffracted to 2.5a. | 2007 | 18045236 |
| epidemiology and clinical presentation of shigellosis in children less than five years of age in rural mozambique. | rectal swabs were collected from 1354 children <5 years of age with diarrhea attending manhiça district hospital and from 227 healthy community controls. shigellosis incidence was high among children aged 12-47 months (488.4/10(5) child-years at risk). fever and dysentery were prominent clinical findings. shigella was more frequently isolated from cases than controls (6.7% versus 0.4%, p = 0.004), and from dysentery than nondysenteric diarrhea (24.1% versus 3.5%, p < 0.001). shigella flexneri 2a ... | 2007 | 17984817 |
| safety and immunogenicity of cvd 1208s, a live, oral deltaguaba deltasen deltaset shigella flexneri 2a vaccine grown on animal-free media. | a previous phase 1 trial demonstrated that shigella flexneri 2a deleted in guaba, sen and set (strain cvd 1208) is well-tolerated and immunogenic after a single oral dose of 10(8) or 10(9) cfu. to facilitate further clinical development, the strain was reconstructed using animal-free media to conform to regulatory guidelines, and designated cvd1208s. healthy inpatient volunteers were randomized (double-blind) to receive a single oral dose of either cvd 1208s (10(8) [n = 7] or 10(9) [n = 7] cfu) ... | 2007 | 17938573 |
| o-antigen modal chain length in shigella flexneri 2a is growth-regulated through rfah-mediated transcriptional control of the wzy gene. | shigella flexneri 2a 2457t produces lipopolysaccharide (lps) with two o-antigen (oag) chain lengths: a short (s-oag) controlled by wzzb and a very long (vl-oag) determined by wzz(phs-2). this study demonstrates that the synthesis and length distribution of the s. flexneri oag are under growth-phase-dependent regulation. quantitative electrophoretic analysis showed that the vl-oag increased during growth while the s-oag distribution remained constant. increased production of vl-oag correlated wit ... | 2007 | 17906147 |
| dynamic proteome changes of shigella flexneri 2a during transition from exponential growth to stationary phase. | shigella flexneri is an infectious pathogen that causes dysentery to human, which remains a serious threat to public health, particularly in developing countries. in this study, the global protein expression patterns of s. flexneri during transition from exponential growth to stationary phase in vitro were analyzed by using 2-d page combined with maldi-tof ms. in a time-course experiment with five time points, the relative abundance of 49 protein spots varied significantly. interestingly, a puta ... | 2007 | 17893076 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| crystal structure of the diadenosine tetraphosphate hydrolase from shigella flexneri 2a. | 2006 | 17006950 | |
| 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 |
| 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 |
| complete genome sequence of shigella flexneri 5b and comparison with shigella flexneri 2a. | shigella bacteria cause dysentery, which remains a significant threat to public health. shigella flexneri is the most common species in both developing and developed countries. five shigella genomes have been sequenced, revealing dynamic and diverse features. to investigate the intra-species diversity of s. flexneri genomes further, we have sequenced the complete genome of s. flexneri 5b strain 8401 (abbreviated sf8401) and compared it with s. flexneri 2a (sf301). | 2006 | 16822325 |
| role of shigella flexneri 2a 34 kda outer membrane protein in induction of protective immune response. | emergence of shigella vaccine is in great need in developing countries. in this paper we have shown that 34 kda shigella flexneri 2a outer membrane protein has a role in eliciting immune responses. when injected parentarally this protein gives significant protection against challenge with virulent shigella flexneri 2a. macrophages activated with the 34 kda protein resulted in the dose dependent production of nitric oxide, the highly reactive free radical responsible for killing of invading bacte ... | 2006 | 16765491 |
| archaeology and evolution of transfer rna genes in the escherichia coli genome. | transfer rna genes tend to be presented in multiple copies in the genomes of most organisms, from bacteria to eukaryotes. the evolution and genomic structure of trna genes has been a somewhat neglected area of molecular evolution. escherichia coli, the first phylogenetic species for which more than two different strains have been sequenced, provides an invaluable framework to study the evolution of trna genes. in this work, a detailed analysis of the trna structure of the genomes of escherichia ... | 2006 | 16618964 |
| genomic divergence of escherichia coli strains: evidence for horizontal transfer and variation in mutation rates. | this report describes the sequencing in the escherichia coli b genome of 36 randomly chosen regions that are present in most or all of the fully sequenced e. coli genomes. the phylogenetic relationships among e. coli strains were examined, and evidence for the horizontal gene transfer and variation in mutation rates was determined. the overall phylogenetic tree indicated that e. coli b and k-12 are the most closely related strains, with e. coli o157:h7 being more distantly related, shigella flex ... | 2005 | 16562379 |
| protection of monkeys against experimental shigellosis with attenuated vaccines. | formal, samuel b. (walter reed army institute of research, washington, d.c.), e. h. labrec, amos palmer, and stanley falkow. protection of monkeys against experimental shigellosis with attenuated vaccines. j. bacteriol. 90:63-68. 1965.-two shigella flexneri 2a strains of reduced virulence were used as oral vaccines to protect monkeys against experimental challenge. one strain, a spontaneous mutant, had lost its ability to cause disease and was unable to penetrate the intestinal epithelium and re ... | 1965 | 16562044 |
| epithelial cell penetration as an essential step in the pathogenesis of bacillary dysentery. | labrec, eugene h., herman schneider, thomas j. magnani, and samuel b. formal. epithelial cell penetration as an essential step in the pathogenesis of bacillary dysentery. j. bacteriol. 88:1503-1518. 1964.-a parent strain of shigella flexneri 2a and a colonial mutant derived from it were studied in three animal models. both strains were equally virulent for mice when living cells suspended in hog gastric mucin were injected by the intraperitoneal route. feeding the parent strain to starved guinea ... | 1964 | 16562000 |
| identification of two widely separated loci conferring nicotinic acid dependence on wild-type shigella flexneri 2a. | two widely separated loci causing the nicotinic acid dependence of wild-type shigella flexneri 2a were identified by intergeneric mating procedures and found to be closely linked to the gal and fuc chromosomal determinants. | 1971 | 16558004 |
| infection of cultured mouse macrophages with shigella flexneri. | virulent, avirulent, and attenuated hybrid strains of shigella flexneri 2a are equally susceptible to phagocytosis by cultured mouse peritoneal macrophages. the virulent strain is highly lethal for the macrophages, whereas the avirulent is not and is killed. the attenuated hybrid strain is intermediate in its lethality. comparable results were obtained by using virulent and avirulent s. flexneri 1b, 3, and 5. destruction of macrophages occurs shortly after infection, suggesting virulent strains ... | 1970 | 16557758 |
| preparation, crystallization and preliminary x-ray crystallographic studies of diadenosine tetraphosphate hydrolase from shigella flexneri 2a. | diadenosine tetraphosphate (ap4a) hydrolase (ec 3.6.1.41) hydrolyzes ap4a symmetrically in prokaryotes. it plays a potential role in organisms by regulating the concentration of ap4a in vivo. to date, no three-dimensional structures of proteins with significant sequence homology to this protein have been determined. the 31.3 kda ap4a hydrolase from shigella flexneri 2a has been cloned, expressed and purified using an escherichia coli expression system. crystals of ap4a hydrolase have been obtain ... | 2005 | 16511239 |
| immunoproteomics of membrane proteins of shigella flexneri 2a 2457t. | to screen the immunogenic membrane proteins of shigella flexneri 2a 2457t. | 2005 | 16425402 |
| characterization of functional oligosaccharide mimics of the shigella flexneri serotype 2a o-antigen: implications for the development of a chemically defined glycoconjugate vaccine. | protection against reinfection with noncapsulated gram-negative bacteria, such as shigella, an enteroinvasive bacterium responsible for bacillary dysentery, is mainly achieved by abs specific for the o-ag, the polysaccharide part of the lps, the major bacterial surface ag. the use of chemically defined glycoconjugates encompassing oligosaccharides mimicking the protective determinants carried by the o-ag, thus expected to induce an efficient anti-lps ab response, has been considered an alternati ... | 2006 | 16424198 |
| development and evaluation of a shigella flexneri 2a and s. sonnei bivalent invasin complex (invaplex) vaccine. | over 160 million cases of shigellosis occur annually worldwide, with the two most prevalent species being shigella flexneri and s. sonnei. protective immunity against shigella infection is primarily directed at the lipopolysaccharide (lps) of the homologous serotype, so it may be necessary to combine monovalent vaccines for multiple shigella serotypes to construct a multivalent vaccine against predominant serotypes. recently, we described a subcellular vaccine isolated from virulent s. flexneri, ... | 2006 | 16364513 |
| a large, multiple-restaurant outbreak of infection with shigella flexneri serotype 2a traced to tomatoes. | foodborne outbreaks of shigella infection are uncommon and tomatoes are an unusual vehicle. we describe a large, multiple-restaurant outbreak of shigella flexneri serotype 2a infection that was associated with tomatoes. | 2006 | 16355324 |
| [construction and characterization of a live attenuated shigella flexneri 2a vaccine strain, sf301 delta virg and dsba33g]. | construction and characterization of a live attenuated shigella flexneria 2a sf301 vaccine strain to prevent the endemic of shigellosis. using chinese majority epidemic shigella flexneri 2a serotype sf301 as the target, p delta virg, a deletion derivation of the virg gene in the sacb suicide vector pcvd442 and pdsba33g, an mutant of a disulfide bond catalyst dsba, replaced its 33 amiano acid cystine by glycerin in pcvd442, were used to generate a attenuated mutant strain sf301: delta virg: dsba3 ... | 2005 | 16342769 |
| purification and preliminary crystallographic studies of cutc, a novel copper homeostasis protein from shigella flexneri. | cutc is a novel copper homeostasis protein containing 248 amino acids. here we report the cloning, expression, purification, crystallization and preliminary x-ray crystallographic studies of cutc from shigella flexneri 2a. purification of cutc and its selenomethionine (semet) derivate were done using immobilized metal ion affinity chromatography, size-exclusion and ion-exchange chromatography. the purified proteins were crystallized using the hanging drop vapor diffusion method. the diffraction ... | 2005 | 16305556 |
| immunoproteomics of outer membrane proteins and extracellular proteins of shigella flexneri 2a 2457t. | shigella flexneri 2a is an important pathogen causing bacillary dysentery in humans. in order to investigate any potential vaccine candidate proteins present in outer membrane proteins (omps) and extracellular proteins of s. flexneri 2a 2457t, we use the proteome mapping and database analyzing techniques. a subproteome map and database of omps were established first. one hundred and nine of the total 126 marked spots were cut out and processed to maldi-tof-ms and pmf. eighty-seven spots were ide ... | 2005 | 16281178 |
| construction, detection and microarray analysis on the shigella flexneri 2a sitc mutant. | in order to overcome the defects of difficult gene operations in low-copy suicide plasmid pcvd442, gateway technology was applied in the construction process of recombinant plasmid for gene knockout in this study. with this improved knockout system, we inactivated sitc gene, which is associated with iron transport in shigella flexneri 2a strain 301, to yield the mutant, mts. the functional detection of the mutant was performed at the level of culture medium, cell and animal experiment, respectiv ... | 2005 | 16092755 |
| [comparative proteomics research on removing of large invasive plasmid pinv of shigella flexneri 2a strain 2457t]. | s. flexneri 2a strain 2457t and its derivative without large invasive plasmid pinv-2457t were cultured to middle logarithm phase. whole cellular protein extracts of the two strains were examined by two dimensional (2d) electrophoresis using immobilized ph gradient (ipg) technology. after in-gel protein digestion, the different-expressed spots were detected by matrix-assisted laser desorption ionization-time of flight mass spectrometry (maldi tof ms). all the peptide mass fingerprints (pmfs) were ... | 2005 | 15989237 |
| construction of a novel shigella live-vector strain co-expressing cs3 and ltb/stm of enterotoxigenic e.coli. | to construct and evaluate a polyvalent recombinant vaccine strain shigella flexneri 2a t32 against enterotoxigenic e.coli (etec). | 2005 | 15948247 |
| synthesis of two linear padre conjugates bearing a deca- or pentadecasaccharide b epitope as potential synthetic vaccines against shigella flexneri serotype 2a infection. | the blockwise synthesis of the 2-aminoethyl glycosides of a deca- and a pentadecasaccharide made of two and three repeating units, respectively, of the shigella flexneri serotype 2a specific polysaccharide is reported. the strategy relies on trifluoromethanesulfonic acid mediated glycosylation of a pentasaccharide building block acting as a glycosyl donor and a potential glycoside acceptor. both targets were made available in amounts large enough for their subsequent conversion into glycoconjuga ... | 2005 | 15669066 |
| a novel intranasal protollin-based measles vaccine induces mucosal and systemic neutralizing antibody responses and cell-mediated immunity in mice. | protollin-mv is a vaccine produced by mixing split measles virus (mv) antigen with the novel adjuvant protollin (neisseria meningitidis outer membrane proteins non-covalently complexed with shigella flexneri 2a lipopolysaccharide). intranasal immunization of mice with two or three doses of protollin-mv induces both serum igg and mucosal iga with strong neutralizing activity. there is a dose-dependent shift towards lower igg1:igg2a ratios and mv-specific ifngamma production in splenocytes. intran ... | 2005 | 15661386 |
| screening and identification of shigella flexneri 2a virulence-related genes induced after invasion of epithelial cells. | an in vivo expression technology (ivet) was applied to screen s. flexneri 2a genes induced after invasion of epithelial cells, and virulence-related genes were further identified by mutational analysis. thirteen intracellular induced genes were identified with a hela cell infection model. of these, two were identified as alkylation-related genes; one was related to metabolism; one encoded a transcriptional regulator; three were identified as insertion elements; three appeared to be antisense to ... | 2004 | 15620105 |
| construction and characterization of bivalent shigella flexneri 2a vaccine strains sc608(pcfai) and sc608(pcfai/ltb) that express antigens from enterotoxigenic escherichia coli. | an invasive strain of shigella flexneri 2a (sc608) has been developed as a vector for the expression and delivery of heterologous antigens. sc608 is an aspartate semialdehyde dehydrogenase (asd) derivative of sc602 (icsa iuc), a well-characterized live attenuated vaccine strain which has undergone several clinical trials in human volunteers. when administered orally at a single 10(4) (cfu) dose, sc602 is both immunogenic and efficacious against shigellosis. using asd-based plasmid vectors, we de ... | 2005 | 15618162 |
| single-molecule approach to bacterial genomic comparisons via optical mapping. | modern comparative genomics has been established, in part, by the sequencing and annotation of a broad range of microbial species. to gain further insights, new sequencing efforts are now dealing with the variety of strains or isolates that gives a species definition and range; however, this number vastly outstrips our ability to sequence them. given the availability of a large number of microbial species, new whole genome approaches must be developed to fully leverage this information at the le ... | 2004 | 15516592 |
| deletion in the shigella enterotoxin genes further attenuates shigella flexneri 2a bearing guanine auxotrophy in a phase 1 trial of cvd 1204 and cvd 1208. | we created a live, attenuated, oral shigella vaccine by constructing a lineage of guanine auxotrophs and conducted a double-blind, placebo-controlled trial to ascertain (1) the attenuation profile of delta guaba shigella flexneri 2a, which harbors deletions in the guanine nucleotide synthesis pathway (cvd 1204); (2) additional attenuation conferred by deletions in set and sen genes encoding shigella enterotoxins (shets) 1 and 2, respectively (cvd 1208); and (3) the relative immunogenicity of the ... | 2004 | 15499528 |
| psi-phi: exploring the outer limits of bacterial pseudogenes. | because bacterial chromosomes are tightly packed with genes and were traditionally viewed as being optimized for size and replication speed, it was not surprising that the early annotations of sequenced bacterial genomes reported few, if any, pseudogenes. but because pseudogenes are generally recognized by comparisons with their functional counterparts, as more genome sequences accumulated, many bacterial pathogens were found to harbor large numbers of truncated, inactivated, and degraded genes. ... | 2004 | 15479949 |
| identification of novel immunogenic proteins of shigella flexneri 2a by proteomic methodologies. | shigella spp. are one of the most important etiological factors for people who are living in developing countries and travelers to tropical countries. high priority has been given by the world health organization to the development of vaccines to control shigellosis caused by these bacteria. however, information regarding to profile of immunogenic proteins of shigella is not available now. in the present study, sub-immunoproteomics was applied to screen novel immunogenic proteins which could be ... | 2004 | 15246607 |
| chromosomal and plasmid-encoded enzymes are required for assembly of the r3-type core oligosaccharide in the lipopolysaccharide of escherichia coli o157:h7. | the type r3 core oligosaccharide predominates in the lipopolysaccharides from enterohemorrhagic escherichia coli isolates including o157:h7. the r3 core biosynthesis (waa) genetic locus contains two genes, waad and waaj, that are predicted to encode glycosyltransferases involved in completion of the outer core. through determination of the structures of the lipopolysaccharide core in precise mutants and biochemical analyses of enzyme activities, waaj was shown to be a udp-glucose:(galactosyl) li ... | 2004 | 15155763 |
| preparation of synthetic glycoconjugates as potential vaccines against shigella flexneri serotype 2a disease. | the synthesis of three neoglycopeptides incorporating carbohydrate haptens, differing in length, covalently linked to a non natural universal t helper peptide is disclosed. they were synthesized according to a blockwise strategy based on the condensation of appropriate di-, tri-, and tetrasaccharide trichloroacetimidate donors onto an azidoethyl 2-acetamido-2-deoxybeta-d-glucopyranoside acceptor. use of thiol-maleimide coupling chemistry allowed site-selective efficient conjugation. | 2004 | 15136809 |
| a dna adenine methylase mutant of shigella flexneri shows no significant attenuation of virulence. | mutants of salmonella defective in dna adenine methylase (dam) have been reported to be attenuated for virulence and to provide protective immunity when used as vaccine strains. to determine whether these observations could be extended to shigella, a dam mutant of shigella flexneri 2a was characterized and examined for the role of dam in pathogenesis. the shigella dam mutant showed some unique characteristics; however, it retained virulence in vivo as well as in vitro. the mutant invaded culture ... | 2004 | 15073316 |
| blockwise approach to fragments of the o-specific polysaccharide of shigella flexneri serotype 2a: convergent synthesis of a decasaccharide representative of a dimer of the branched repeating unit. | the d'a'b'(e')c'dab(e)c decasaccharide representative of a dimer of a frame-shifted pentasaccharide repeating unit of the o-specific polysaccharide of shigella flexneri 2a was synthesized as its methyl glycoside by condensing a pentasaccharide donor (d'a'b'(e')c') and a pentasaccharide acceptor (dab(e)c-ome). several convergent routes to these two building blocks, involving either the ab linkage or the bc linkage as the disconnection site, were evaluated in comparison to the linear strategy. the ... | 2004 | 14961653 |
| two studies evaluating the safety and immunogenicity of a live, attenuated shigella flexneri 2a vaccine (sc602) and excretion of vaccine organisms in north american volunteers. | we report the first community-based evaluation of shigella flexneri 2a strain sc602, a live, oral vaccine strain attenuated by deletion of the icsa (virg) plasmid virulence gene, given at 10(4) cfu. the primary objectives of this trial were to determine the safety and immunogenicity of the vaccine and to determine the duration of colonization. four of 34 volunteers experienced transient fevers, and three reported diarrhea during the first 3 days of the study. half of the volunteers mounted a pos ... | 2004 | 14742537 |
| identification of alka gene related to virulence of shigella flexneri 2a by mutational analysis. | in vivo induced genes are thought to play an important role during infection of host. alka was identified as an in vivo-induced gene by in vivo expression technology (ivet), but its virulence in shigella flexneri was not reported. the purpose of this study was to identify the role of alka gene in the pathogenesis of s. flexneri. | 2003 | 14669321 |
| identification and characterization of simple sequence repeats in the genomes of shigella species. | a variety of simple sequence repeats (ssrs) have been identified in the genome of shigella flexneri serotype 2a (strain sf301), an enteric pathogen that causes bacillary dysentery in man. the distribution of ssrs, with unit length ranging from 1 to 9 nucleotides, was biased in different regions of the genome. the tri-, tetra- and hexanucleotide ssrs prevailed in the coding regions while the mono- and dinucleotide ssrs were more common in the noncoding regions. many intergenic ssrs are less than ... | 2003 | 14644500 |
| [co-expression of cfa/i and cs6 of enterotoxigenic escherichia coli ( etec ) in shigella flexneri 2a t32 derivative strain fwl01]. | among the known colonization factors of enterotoxigenic escherichia coli (etec), cfa/i and cs6 (the common antigen in the cfa/iv fimbrial antigens ) are two of the most prevalent fimbriae found in clinical isolates but are never expressed by the same wild-type strains. in this study, cfa/i and cs6 of etec were co-expressed in shigella flexneri 2a t32 derivative strain fwl01 by using a host-plasmid lethal balancing system based on asd gene. the results indicate that the recombinant plasmid carryi ... | 2003 | 14614538 |
| salicin-fermenting variant of shigella flexneri serotype 2a. | 1965 | 14345179 | |
| shigellosis in cynomolgus monkeys (macaca irus). ii. experimental infection with shigella flexneri 2a with special references to clinical and bacteriological findings. | 1964 | 14279864 | |
| virulence of escherichia-shigella genetic hybrids for the guinea pig. | falkow, stanley (walter reed army institute of research, washington, d.c.), h. schneider, l. s. baron, and s. b. formal. virulence of escherichia-shigella hybrids for the guinea pig. j. bacteriol. 86:1251-1258. 1963.-genetic recombination studies between donor escherichia coli and recipient shigella flexneri 2a strains were employed to examine alterations in the virulence of shigella hybrids for guinea pigs. the genetic studies indicated that several chromosomal regions of e. coli and s. flexner ... | 1963 | 14086097 |