Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| [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 |
| 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 |
| molecular epidemiology of the srl pathogenicity island. | the shigella resistance locus (srl), which is carried on the srl pathogenicity island (pai) in shigella flexneri 2a ysh6000, mediates resistance to the antibiotics streptomycin, ampicillin, chloramphenicol, and tetracycline. in the present study, we investigated the distribution and structural variation of the srl and the srl pai in 71 shigella isolates and 28 other enteric pathogens by pcr and southern analysis. the srl and srl-related loci, although absent from the other enteric pathogens eval ... | 2003 | 12543684 |
| 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 |
| 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 |
| 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 |
| 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 |
| three-way interactions among the sfh, stpa and h-ns nucleoid-structuring proteins of shigella flexneri 2a strain 2457t. | shigella flexneri 2a strain 2457t has been found to express sfh, a new member of the h-ns-like family of nucleoid-structuring proteins. with h-ns and its paralogue, stpa, this brings to three the number of these proteins expressed in this bacterium. this raises the possibility that three-way interactions may occur in s. flexneri among these proteins and between the proteins and each other's genes. such three-way interactions among h-ns-like proteins have not been described previously. the expres ... | 2003 | 12787365 |
| protective efficacy of oral immunization with heat-killed shigella flexneri 2a in animal model: study of cross protection, immune response and antigenic recognition. | oral immunization of rabbits with four doses of 10(11) heat-killed shigella flexneri 2a showed 100% protection against challenge with virulent s. flexneri 2a. after orally immunizing guinea pigs with four doses of heat-killed s. flexneri 2a 100% protection could be shown against ocular challenge with the same virulent s. flexneri 2a strain but this conferred no protection against challenge with shigella dysenteriae type 1. in enzyme-linked immunosorbent assay (elisa) and immunoblot experiments b ... | 2003 | 12798648 |
| molecular epidemiology of shigella in a taiwan township during 1996 to 2000. | a previously identified shigella flexneri serotype 2a strain was responsible for an outbreak of shigellosis in a taiwan township in august 1996. in order to find the relationship between this outbreak strain and subsequent shigella infections in the area, 59, 47, 35, and 20 shigella isolates recovered in 1997, 1998, 1999, and 2000, respectively, were collected and typed by serological and pulsed-field gel electrophoresis (pfge) techniques. of these 161 isolates, 139 isolates were s. flexneri ser ... | 2003 | 12843047 |
| [alteration of phagocyte functional activity depending on the presence of pr50 plasmid in bacteria]. | the relationship between the presence, or the absence, of conjugative plasmid pr50 detected in klebsiella oxytoca 89, in the isogenic pairs of attenuated strains shigella flexneri 2a 516 near and salmonella typhimurium 129 rifr and the regeneration of the active forms of oxygen by mouse peritoneal phagocytizing cells was studied. as indicated by the data obtained in the course of the experiment, plasmids pr50 could influence the chemiluminescent response of phagocytes. the inhibition of the synt ... | 2003 | 12886622 |
| conversion of shigella flexneri serotype 2a to serotype y in a shigellosis patient due to a single amino acid substitution in the protein product of the bacterial glucosyltransferase gtrii gene. | conversion of serotype from 2a to y was demonstrated with five shigella flexneri isolates recovered from an infected patient. when introduced into the serotype y isolate, the glucosyltransferase (gtr) ii gene of the serotype 2a isolate is capable of inducing the conversion from serotype y to 2a. in contrast, the gtrii of the serotype y isolate lacks the capacity to change serotype, resulting from a cys-->tyr substitution in its predicted protein sequence. the protein product of the gtrii gene wa ... | 2003 | 12892893 |
| shigella flexneri 2a strain 2457t expresses three members of the h-ns-like protein family: characterization of the sfh protein. | shigella flexneri 2a is known to express the h-ns nucleoid-structuring protein and the paralogous protein stpa. using bioinformatic analysis we have now discovered a third member of the h-ns protein family, sfh (shigella flexneri h-ns-like protein), in strain 2457t. this protein is encoded by the sfh gene, which is located on a high-molecular-mass plasmid that is closely related to the self-transmissible plasmid r27. when expressed in escherichia coli, the sfh protein can complement an hns null ... | 2003 | 12898223 |
| safety and immunogenicity of shigella sonnei-crm9 and shigella flexneri type 2a-repasucc conjugate vaccines in one- to four-year-old children. | shigella conjugate vaccines have been shown to be safe, immunogenic and efficacious in adult volunteers. we have now investigated the safety and immunogenicity of investigational shigella sonnei and shigella flexneri 2a conjugate vaccines in 1- to 4-year-old children, the age group at greatest risk for shigellosis. | 2003 | 12913770 |
| survival, growth, and inactivation of acid-stressed shigella flexneri as affected by ph and temperature. | a study was done to determine the survival, growth, and inactivation characteristics of unadapted, acid-adapted, and acid-shocked shigella flexneri 2a cells as affected by ph and temperature. the pathogen was grown at 37 degrees c for 18 h in tryptic soy broth containing no glucose (tsbng) (unadapted cells) and tsbng supplemented with 1% glucose (tsbg) (acid-adapted cells). cells grown in tsbng were acid-shocked by adjusting 18-h cultures to ph 4.5+/-0.05 with lactic acid. all three cell types w ... | 2003 | 12927715 |
| new mannitol negative variety of shigella flexneri 2a. | 1956 | 13421654 | |
| microscopic characteristics of colonies of shigella flexneri 2a and 2b and their relation to antigenic composition, mouse virulence and immunogenicity. | 1957 | 13429082 | |
| experimental shigella infections. v. studies in germ-free guinea pigs. | formal, samuel b., (walter reed army institute of research, washington, d. c.), gustave dammin, helmuth sprinz, donald kundel, herman schneider, richard e. horowitz, and martin forbes. experimental shigella infections. v. studies in germ-free guinea pigs. j. bacteriol. 82:284-287. 1961.-germ-free guinea pigs succumb after oral infection with shigella flexneri serotype 2a; they survive a similar challenge with either a strain of escherichia coli or a culture of lactobacillus. animals monocontamin ... | 1961 | 13700794 |
| [mannitol-negative variation of shigella flexneri 2a]. | 1963 | 13944418 | |
| [phage typing of shigella. iii. stability of the bacteriophage types in shigella flexneri 2a]. | 1962 | 13956957 | |
| 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 |
| shigellosis in cynomolgus monkeys (macaca irus). ii. experimental infection with shigella flexneri 2a with special references to clinical and bacteriological findings. | 1964 | 14279864 | |
| salicin-fermenting variant of shigella flexneri serotype 2a. | 1965 | 14345179 | |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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, 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| immunoproteomics of membrane proteins of shigella flexneri 2a 2457t. | to screen the immunogenic membrane proteins of shigella flexneri 2a 2457t. | 2005 | 16425402 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| crystal structure of the diadenosine tetraphosphate hydrolase from shigella flexneri 2a. | 2006 | 17006950 | |
| 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 |
| 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 |
| 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 |
| new animal model of shigellosis in the guinea pig: its usefulness for protective efficacy studies. | it has been difficult to evaluate the protective efficacy of vaccine candidates against shigellosis, a major form of bacillary dysentery caused by shigella spp. infection, because of the lack of suitable animal models. to develop a proper animal model representing human bacillary dysentery, guinea pigs were challenged with virulent shigella flexneri serotype 2a (strains 2457t or ysh6000) or s. flexneri 5a (strain m90t) by the intrarectal (i.r.) route. interestingly, all guinea pigs administered ... | 2007 | 17277155 |
| gene expression profiling of the ph response in shigella flexneri 2a. | the ph response of shigella flexneri 2a 301 was identified by gene expression profiling. gene expression profiles of cells grown in ph 4.5 or 8.6 were compared with the profiles of cells grown at ph 7.0. differential expression was observed for 307 genes: 97 were acid up-regulated, 102 were acid down-regulated, 91 were base up-regulated, and 86 were base down-regulated. twenty-seven genes were found to be both acid and base up-regulated, and 29 genes were both acid and base down-regulated. this ... | 2007 | 17286558 |
| o-specific [corrected] polysaccharide conjugate vaccine-induced [corrected] antibodies prevent invasion of shigella into caco-2 cells and may be curative. | the o-specific polysaccharide (o-sp) domain of shigella lps is both an essential virulence factor and a protective antigen for this genus. a critical level of serum igg anti-o-sp was shown to confer immunity to shigellosis, likely by complement-mediated bacteriolysis of the inoculum. conjugate shigella o-sp vaccines were shown to be safe and immunogenic in children, and, in a preliminary study, shigella sonnei vaccine was protective in young adults. characteristic of shigellosis is bacterial inv ... | 2007 | 17287349 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |