| preparation and characterization of translocator/chaperone complexes and their component proteins from shigella flexneri. | shigella flexneri causes a severe form of bacillary dysentery also known as shigellosis. onset of shigellosis requires bacterial invasion of colonic epithelial cells which is initiated by the delivery of translocator and effector proteins to the host cell membrane and cytoplasm, respectively, by the shigella type iii secretion system (ttss). the shigella translocator proteins, ipab and ipac, form a pore complex in the host cell membrane to facilitate effector delivery; however, prior to their se ... | 2007 | 17571858 |
| a deafness-associated mutant human connexin 26 improves the epithelial barrier in vitro. | a large proportion of recessive nonsyndromic hearing loss is due to mutations in the gjb2 gene encoding connexin 26 (cx26), a component of a gap junction. within different ethnic groups there are specific common recessive mutations, each with a relatively high carrier frequency, suggesting the possibility of heterozygous advantage. carriers of the r143w gjb2 allele, the most prevalent in the african population, present with a thicker epidermis than noncarriers. in this study, we show that (r143w ... | 2007 | 17581693 |
| genetic structure of the nada and nadb antivirulence loci in shigella spp. | comparison of nada and nadb in 14 shigella strains and enteroinvasive escherichia coli versus e. coli showed that at least one locus is altered in all strains. these observations explain the characteristic nicotinic acid auxotrophy of shigella organisms and are consistent with the previously identified antivirulence nature of these genes for these pathogens. | 2007 | 17586625 |
| shigella flexneri bacteriuria in a saudi child. | | 1992 | 17587005 |
| [study of antibiotic sensitivity of diarrheal microorganisms]. | as it was shown previously, detailed bacteriological analyses of 159 strains, among them museum and newly isolated strains of diarrheal patients from various clinics and bacteriology laboratories of tbilisi was carried out. study of antibiotic susceptibility of 52 strains of salmonella groups a, b, c, d, e and 42 shigella strains, among them 30 shigella flexneri and 12 shigella sonnei strains to 20 antibiotics and 1 chemical preparation was performed. 63% of salmonella strains were susceptible t ... | 2007 | 17595461 |
| analysis of the aerobactin and ferric hydroxamate uptake systems of yersinia pestis. | yersinia pestis genomes contain genes homologous to the aerobactin receptor (iuta) and biosynthetic genes (iucabcd) as well as the ferric hydroxamate uptake system (fhucdb) of escherichia coli. however, iuca is disrupted by a frameshift mutation. an e. coli strain carrying the cloned y. pestis aerobactin region was unable to produce aerobactin, but could use the siderophore as an iron source. repair of the frameshift mutation in iuca did not allow aerobactin production in e. coli or y. pestis. i ... | 2007 | 17600077 |
| nada and nadb of shigella flexneri 5a are antivirulence loci responsible for the synthesis of quinolinate, a small molecule inhibitor of shigella pathogenicity. | the evolution of bacterial pathogens from commensal organisms involves virulence gene acquisition followed by pathoadaptation to the new host, including inactivation of antivirulence loci (avl). avl are core ancestral genes whose expression is incompatible with the pathogenic lifestyle. previous studies identified cada (encoding lysine decarboxylase) as an avl of shigella spp. in this study, avl of shigella were identified by examining a phenotypic difference from its non-pathogenic ancestor, es ... | 2007 | 17600080 |
| risk areas and neighborhood-level risk factors for shigella dysenteriae 1 and shigella flexneri. | annually, there are 165 million cases of shigellosis resulting in 1.1 million deaths in the developing world. two species of the causative agent, shigella dysenteriae 1 and shigella flexneri, are responsible for acute diarrheal illness. vaccines are being developed against both but many questions remain about the disease burden, distribution of species in space and time, and community-level risk factors. this study answers two questions. what are the differences in neighborhood-level risk factor ... | 2008 | 17602851 |
| differences in the electrostatic surfaces of the type iii secretion needle proteins prgi, bsal, and mxih. | gram-negative bacteria use a needle-like protein assembly, the type iii secretion apparatus, to inject virulence factors into target cells to initiate human disease. the needle is formed by the polymerization of approximately 120 copies of a small acidic protein that is conserved among diverse pathogens. we previously reported the structure of the bsal needle monomer from burkholderia pseudomallei by nuclear magnetic resonance (nmr) spectroscopy and others have determined the crystal structure o ... | 2007 | 17617421 |
| distribution of serogroups and serotypes of multiple drug resistant shigella isolates. | summary | 2007 | 17622331 |
| site-specific modification of shigella flexneri virf mrna by trna-guanine transglycosylase in vitro. | shigella flexneri is an enteropathogen responsible for severe dysentery in humans. virf is a key transcriptional regulator that activates the expression of the downstream virulence factors required for cellular invasion and cell-to-cell spread of this pathogen. there are several environmental factors that induce the translation of virf including temperature, ph, osmolarity and post-transcriptional rna modification. durand and colleagues (vacc, a virulence-associated chromosomal locus of shigella ... | 2007 | 17626052 |
| study of predominant bacterial antigens triggering antibody response in salmonella reactive arthritis: apropos of a case. | reactive arthritis (rea) is a sterile arthritis triggered by distal mucosal infection, which suggests a contribution from bacterial products. the pathogenesis of rea is unclear. there are no international standards for the serological methods used to confirm rea. in the present work, we analyzed the predominant bacterial component that triggered an immune response in a 24-year-old woman with acute rea. the candidate bacterial trigger was investigated by measuring the antibacterial antibodies (al ... | 2007 | 17642539 |
| high prevalence of ctx-m-15 extended-spectrum beta-lactamase among contacts of patients with shigellosis due to shigella flexneri carrying ctx-m-15. | | 2007 | 17646198 |
| anaerobic regulation of shigella flexneri virulence: arca regulates fur and iron acquisition genes. | invasion and plaque formation in epithelial monolayers are routinely used to assess the virulence of shigella flexneri, a causative agent of dysentery. a modified plaque assay was developed to identify factors contributing to the virulence of s. flexneri under the anaerobic conditions present in the colon. this assay demonstrated the importance of the ferrous iron transport system feo, as well as the global transcription factors fur, arca, and fnr, for shigella plaque formation in anoxic environ ... | 2007 | 17660284 |
| identification of minor inner-membrane components of the shigella type iii secretion system 'needle complex'. | type iii secretion systems (t3sss or secretons) are central virulence factors of many gram-negative bacteria, used to inject protein effectors of virulence into eukaryotic host cells. their overall morphology, consisting of a cytoplasmic region, an inner- and outer-membrane section and an extracellular needle, is conserved in various species. a portion of the secreton, containing the transmembrane regions and needle, has been isolated biochemically and termed the 'needle complex' (nc). however, ... | 2007 | 17660405 |
| the acid-resistance pathways of shigella flexneri 2457t. | the stationary-phase acid-resistance pathways of shigella flexneri 2457t have not previously been studied. the two acid-resistance systems, the glutamate-dependent acid-resistance (gdar) and the oxidative pathways, reported elsewhere for escherichia coli and s. flexneri 3136, were both detected in s. flexneri 2457t. however, s. flexneri 2457t cells grown overnight under fermentative conditions and acid-shocked in minimal media in the absence of glutamate, an acid test often described as a negati ... | 2007 | 17660423 |
| shigella flexneri phagosomal escape is independent of invasion. | infections with salmonella enterica serovar typhimurium and shigella flexneri result in mucosal inflammation in response to epithelial cell invasion and macrophage cytotoxicity. these processes are mediated by type iii secretion systems encoded in homologous virulence loci in the two species, namely, salmonella pathogenicity island 1 (spi-1), carried in the genome, and the shigella entry region (ser), carried in a large virulence plasmid. here we show that spi-1 can functionally complement a del ... | 2007 | 17664266 |
| genes under positive selection in escherichia coli. | we used a comparative genomics approach to identify genes that are under positive selection in six strains of escherichia coli and shigella flexneri, including five strains that are human pathogens. we find that positive selection targets a wide range of different functions in the e. coli genome, including cell surface proteins such as beta barrel porins, presumably because of the involvement of these genes in evolutionary arms races with other bacteria, phages, and/or the host immune system. st ... | 2007 | 17675366 |
| escherichia coli, shigella and salmonella species in acute diarrhoea in hamedan, islamic republic of iran. | this study investigated the frequency of escherichia col, shigella and salmonella species in stool specimens from patients with diarrhoea presenting to health centres in hamedan province, islamic republic of iran. from 144 samples, shigella strains were isolated in 17 cases (11.8%): 10 sh. flexneri, 3 sh. sonnei, 2 sh. boydii and 2 untyped strains. no salmonella strains were isolated. using molecular diagnostic methods, diarrheogenic e. coli were detected in 37 cases (25.7%), the majority were e ... | 2007 | 17684844 |
| [ekiri syndrome complicating shigellosis]. | | 2007 | 17692219 |
| [intrafamilial outbreak of shigella flexneri gastroenteritis in madrid]. | | 2007 | 17692266 |
| differential regulation of caspase-1 activation, pyroptosis, and autophagy via ipaf and asc in shigella-infected macrophages. | shigella infection, the cause of bacillary dysentery, induces caspase-1 activation and cell death in macrophages, but the precise mechanisms of this activation remain poorly understood. we demonstrate here that caspase-1 activation and il-1beta processing induced by shigella are mediated through ipaf, a cytosolic pattern-recognition receptor of the nucleotide-binding oligomerization domain (nod)-like receptor (nlr) family, and the adaptor protein apoptosis-associated speck-like protein containin ... | 2007 | 17696608 |
| omptin proteins: an expanding family of outer membrane proteases in gram-negative enterobacteriaceae. | the escherichia coli k-12 outer membrane protein ompt is a prototype of a unique family of bacterial endopeptidases known as the omptins. this family includes ompt and ompp of e. coli, sopa of shigella flexneri, pgte of salmonella enterica, and pla of yersinia pestis. despite their sequence similarities, the omptins vary in their reported functions. the ompt protease is characterized by narrow cleavage specificity defined by the extracellular loops of the beta-barrel protruding above the lipid b ... | 2007 | 17710644 |
| spontaneous zygogenesis, a wide-ranging mating process in bacteria. | spontaneous zygogenesis (or z-mating) in escherichia coli, unlike f-mediated conjugation, promotes formation of complete zygotes. most z-mating products have proven to be phenotypically unstable, losing part of the phenotype for which they were selected. persistent z-mating products appear as stable genetic recombinants or yield subclones of two types: either both parental types or one of them plus a recombinant type, and the ability to promote spontaneous zygogenesis can appear in all emerging ... | 2007 | 17720456 |
| an inducible lambdoid prophage encoding cytolethal distending toxin (cdt-i) and a type iii effector protein in enteropathogenic escherichia coli. | cytolethal distending toxins (cdts) are inhibitory cyclomodulins, which block eukaryotic cell proliferation and are produced by a diverse group of gram-negative bacteria, including escherichia coli strains associated with intestinal and extraintestinal infections. however, the mode of transmission of the toxin gene clusters among diverse bacterial pathogens is unclear. we found that cdt-i produced by enteropathogenic e. coli strains associated with diarrhea is encoded by a lambdoid prophage, whi ... | 2007 | 17726095 |
| intracellular type iii secretion by cytoplasmic shigella flexneri promotes caspase-1-dependent macrophage cell death. | the gram-negative bacterium shigella flexneri triggers pro-inflammatory apoptotic cell death in macrophages, which is crucial for the onset of an acute inflammatory diarrhoea termed bacillary dysentery. the mxi-spa type iii secretion system promotes bacterial uptake and escape into the cytoplasm, where, dependent on the translocator/effector protein ipab, caspase-1 [interleukin (il)-1beta-converting enzyme] and its substrate il-1beta are activated. here, we show that in the course of a macrophag ... | 2007 | 17768231 |
| [total and specific iga in colostrum and milk of mothers of natal-rio grande do norte, brasil]. | to determine the concentration of total secretory iga and evaluate the repertoire of iga antibodies to enteropathogenic escherichia coli and shigella flexneri antigens in colostrums and milk from mothers in natal, rn. | 2005 | 17768806 |
| antibody response in man to injection of the specific antigen of type v shigella paradysenteriae. | | 1944 | 17772139 |
| cross-species cluster co-conservation: a new method for generating protein interaction networks. | co-conservation (phylogenetic profiles) is a well-established method for predicting functional relationships between proteins. several publicly available databases use this method and additional clustering strategies to develop networks of protein interactions (cluster co-conservation (ccc)). ccc has previously been limited to interactions within a single target species. we have extended ccc to develop protein interaction networks based on co-conservation between protein pairs across multiple sp ... | 2007 | 17803817 |
| identification of the mxih needle protein residues responsible for anchoring invasion plasmid antigen d to the type iii secretion needle tip. | the pathogenesis of shigella flexneri requires a functional type iii secretion apparatus to serve as a conduit for injecting host-altering effector proteins into the membrane and cytoplasm of the targeted cell. the type iii secretion apparatus is composed of a basal body and an exposed needle that is an extended polymer of mxih with a 2.0-nm inner channel. invasion plasmid antigen d (ipad) resides at the tip of the needle to control type iii secretion. the atomic structures of mxih and ipad have ... | 2007 | 17827155 |
| transcriptional profile induced by furazolidone treatment of shigella flexneri. | shigella flexneri is a facultative intracellular pathogen responsible for endemic shigellosis especially in developing countries. furazolidone, a nitrofuran derivative, is very effective against the infection with s. flexneri. to examine potential effects of furazolidone on this germ, a whole-genome dna microarray was constructed and transcriptional profiles of the responses to furazolidone were determined. the expressing data revealed adaptive responses of s. flexneri to oxidative stress induce ... | 2007 | 17851659 |
| isolation and antibiotic susceptibility of salmonella and shigella strains isolated from children in gaza, palestine from 1999 to 2006. | diarrhea and acute gastroenteritis are among the leading causes of illnesses and death in infants and children throughout the world, especially in developing countries, globally, salmonella and shigella remain the major contributors to acute enteric infections and diarrhea. | 2008 | 17854424 |
| plasmid-mediated quinolone resistance conferred by qnrs1 in salmonella enterica serovar virchow isolated from turkish food of avian origin. | to study the molecular characteristics of the quinolone and associated ampicillin resistance mechanisms present in salmonella enterica serovar virchow isolated from turkish foods. | 2007 | 17881633 |
| 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 |
| the type iii secretion system of proteus mirabilis hi4320 does not contribute to virulence in the mouse model of ascending urinary tract infection. | the gram-negative enteric bacterium proteus mirabilis is a frequent cause of urinary tract infections (utis) in individuals with long-term indwelling catheters or with complicated urinary tracts. the recent release of the p. mirabilis strain hi4320 genome sequence has facilitated identification of potential virulence factors in this organism. genes appearing to encode a type iii secretion system (ttss) were found in a low gc-content pathogenicity island in the p. mirabilis chromosome. this islan ... | 2007 | 17893161 |
| 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 |
| identification of newly recognized serotype 1c as the most prevalent shigella flexneri serotype in northern rural vietnam. | we investigated the identity of 37 shigella flexneri strains that had previously been isolated from northern rural vietnam (son tay province) and described as untypable. twenty-four isolates reacted with masf 1c, a monoclonal antibody specific for s. flexneri serotype 1c. a further ten untypable isolates were found to be rough mutants (no longer expressing o-antigen) that were derived from serotype 1c strains. pulsed-field gel electrophoresis demonstrated that these strains consisted of many dif ... | 2008 | 17922932 |
| a role for nod-like receptors in autophagy induced by shigella infection. | shigella infection, the cause of bacillary dysentery, induces caspase-1 activation and cell death in macrophages, but the precise mechanisms remain poorly understood. in our recent study, we presented evidence that caspase-1 activation and il-1beta processing induced by shigella are mediated through ipaf, a cytosolic pattern-recognition receptor of the nucleotide-binding oligomerization domain (nod)-like receptor (nlr) family and the adaptor protein apoptosis-associated speck-like protein contai ... | 2008 | 17932464 |
| vinculin binding in its closed conformation by a helix addition mechanism. | vinculin links integrin receptors to the actin cytoskeleton by binding to talin. vinculin is held in an inactive, closed-clamp conformation through hydrophobic interactions between its head and tail domains, and vinculin activation has long been thought to be dependent upon severing the head-tail interaction. talin, alpha-actinin, and the invasin ipaa of shigella flexneri sever vinculin's head-tail interaction by inserting an alpha-helix into vinculin's n-terminal four-helical bundle, provoking ... | 2007 | 17932491 |
| 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 |
| transcription-termination-mediated immunity and its prevention in bacteriophage sfv of shigella flexneri. | the temperate phage sfv encodes the genes responsible for the serotype conversion of shigella flexneri strains from serotype y to 5a. bacteriophages often encode proteins that prevent subsequent infection by homologous phages; the mechanism by which this is accomplished is referred to as superinfection immunity. the serotype conversion mediated following lysogenization of sfv is one such mechanism. another mechanism is the putative lambda-like ci protein within sfv. this study reports the charac ... | 2007 | 17947546 |
| synthesis, characterization and antibacterial activity of cobalt(iii) complexes with pyridine-amide ligands. | the ligands 2-(n-(x-pyridyl)carbamoyl)pyridine (x=2, 3 or 4 for hl1-hl3, respectively) and 2,6-bis(n-(y-pyridyl)carbamoyl)pyridine (y=2, 3 or 4 for h2l4-h2l6, respectively) in their mono- and di-deprotonated forms have been used to synthesize kinetically stable cobalt(iii) compounds [co(l1-3)3] (1-3) and na[co(l4-6)2] (4-6), respectively. the co(iii) ion is in octahedral environment and is surrounded by three bidentate ligands in complexes 1-3 and two tridentate ligands in complexes 4-6. ligands ... | 2008 | 17959275 |
| crystal structure of an apo form of shigella flexneri arsh protein with an nadph-dependent fmn reductase activity. | the arsh gene or its homologs are a frequent part of the arsenic resistance system in bacteria and eukaryotes. although a specific biological function of the gene product is unknown, the arsh protein was annotated as a member of the nadph-dependent fmn reductase family based on a conserved (t/s)xrxxsx(t/s) fingerprint motif common for fmn binding proteins. presented here are the first crystal structure of an arsh protein from shigella flexneri refined at 1.7 a resolution and results of enzymatic ... | 2007 | 17962405 |
| multilocus sequence typing analysis of shigella flexneri isolates collected in asian countries. | the multilocus sequence typing scheme used previously for phylogenetic analysis of escherichia coli was applied to 107 clinical isolates of shigella flexneri. dna sequencing of 3423 bp throughout seven housekeeping genes identified eight new allele types and ten new sequence types among the isolates. s. flexneri serotypes 1-5, x and y were clustered together in a group containing many allelic variants while serotype 6 formed a distinct group, as previously established. | 2007 | 17965345 |
| [rapid detection of three foodborne pathogenic bacteria by multiplex polymerase chain reaction-capillary electrophoresis with laser induced fluorescence detector]. | a method for monitoring foodborne pathogenic bacteria by multiplex polymerase chain reaction (pcr)--capillary electrophoresis (ce) with a laser induced fluorescence detector was developed. three sets of primers were designed to amplify the gene segments of uida gene in e. coli. o157:h7, inva gene in salmonella and ipah gene in shigella, individually. the multiple pcr system and the separation conditions of ce were optimized. using a capillary coated with linear polyacrylamide and sieving buffer ... | 2007 | 17970100 |
| the pattern-recognition molecule nod1 is localized at the plasma membrane at sites of bacterial interaction. | the pattern-recognition molecule nod1 is a critical sensor for bacterial derived diaminopimelic acid-containing peptidoglycan fragments which induces innate immune responses in epithelial cells. here we report the subcellular localization of this protein in human epithelial cells. nod1 is localized in the cytosol and at the plasma membrane in human cells. this membrane association is dependent on the integrity of the protein, on its signalling capacity and on an intact actin cytoskeleton. signal ... | 2008 | 17970764 |
| the nlee/ospz family of effector proteins is required for polymorphonuclear transepithelial migration, a characteristic shared by enteropathogenic escherichia coli and shigella flexneri infections. | enteropathogenic escherichia coli (epec) and shigella flexneri are human host-specific pathogens that infect intestinal epithelial cells. however, each bacterial species employs a different infection strategy within this environmental niche. epec attaches to the apical surface of small intestine enterocytes, causing microvillus effacement and rearrangement of the host cell cytoskeleton beneath adherent bacteria. in contrast, s. flexneri invades the large intestine epithelium at the basolateral m ... | 2008 | 17984206 |
| 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 |
| type iii secretion effectors of the ipah family are e3 ubiquitin ligases. | many bacteria pathogenic for plants or animals, including shigella spp., which is responsible for shigellosis in humans, use a type iii secretion apparatus to inject effector proteins into host cells. effectors alter cell signaling and host responses induced upon infection; however, their precise biochemical activities have been elucidated in very few cases. utilizing saccharomyces cerevisiae as a surrogate host, we show that the shigella effector ipah9.8 interrupts pheromone response signaling ... | 2007 | 18005683 |
| microbial pathogen-induced necrotic cell death mediated by the inflammasome components cias1/cryopyrin/nlrp3 and asc. | cryopyrin (cias1, nlrp3) and asc are components of the inflammasome, a multiprotein complex required for caspase-1 activation and cytokine il-1beta production. cias1 mutations underlie autoinflammation characterized by excessive il-1beta secretion. disease-associated cryopyrin also causes a program of necrosis-like cell death in macrophages, the mechanistic details of which are unknown. we find that patient monocytes carrying disease-associated cias1 mutations exhibit excessive necrosis-like dea ... | 2007 | 18005730 |
| bacteriological and antigenic analysis of shigella paradysenteriae sonne isolated from 9 cases. | | 1932 | 18013462 |
| isolation of shigella paradysenteriae type p288 of boyd from a case of acute diarrhea. | | 1944 | 18016092 |
| secretory iga mediates bacterial translocation to dendritic cells in mouse peyer's patches with restriction to mucosal compartment. | in addition to fulfilling its function of immune exclusion at mucosal surfaces, secretory iga (siga) ab exhibits the striking feature to adhere selectively to m cells in the mouse and human intestinal peyer's patches (pps). subsequent uptake drives the siga ab to dendritic cells (dcs), which become partially activated. using freshly isolated mouse dcs, we found that the interaction with siga was tissue and dc subtype dependent. only dcs isolated from pps and mesenteric lymph nodes interacted wit ... | 2007 | 18025221 |
| the distribution of insertion sequences in the genome of shigella flexneri strain 2457t. | shigella flexneri, which causes shigellosis in humans, evolved from escherichia coli. the sequencing of shigella genomes has revealed that a large number of insertion sequence (is) elements (over 200 elements) reside in the genome. although the presence of these elements has been noted previously and summarized, more detailed analyses are required to understand their evolutionary significance. here, the genome of s. flexneri strain 2457t is used to investigate the spatial distribution of is copi ... | 2007 | 18031340 |
| saccharomyces boulardii interferes with shigella pathogenesis by postinvasion signaling events. | saccharomyces boulardii is gaining in popularity as a treatment for a variety of diarrheal diseases as well as inflammatory bowel disease. this study was designed to examine the effect of this yeast on infection by shigella flexneri, a highly infectious and human host-adapted enteric pathogen. we investigated key interactions between the bacteria and host cells in the presence of the yeast in addition to a number of host responses including proinflammatory events and markers. although the presen ... | 2008 | 18032477 |
| changing patterns of antimicrobial susceptibility of shigella serotypes isolated from children with acute diarrhea in manipal, south india, a 5 year study. | this study was carried out to determine the current pattern of shigella serogroups and their antimicrobial resistance in children with acute gastroenteritis in manipal, south india. a total of 1,200 stool samples were collected from april 2001 to may 2006 in children suffering from acute gastroenteritis attending the out-patient department of pediatrics at kasturba hospital, manipal, south india. these samples were cultured for enteric pathogens. the isolates were confirmed to be shigella by bio ... | 2007 | 18041303 |
| muramylpeptide shedding modulates cell sensing of shigella flexneri. | bacterial infections trigger the activation of innate immunity through the interaction of pathogen-associated molecular patterns (pamps) with pattern recognition molecules (prms). the nucleotide-binding oligomerization domain (nod) proteins are intracellular prms that recognize muramylpeptides contained in peptidoglycan (pgn) of bacteria. it is still unclear how nod1 physically interacts with pgn, a structure internal to the gram-negative bacterial envelope. to contribute to the understanding of ... | 2008 | 18042252 |
| 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 |
| comparing invasive and non-invasive of isolated shigella flexneri by electron microscopy of cell culture, sds-page and congo red method. | the aim of this study was to compare invasive and non-invasive strains of shigella flexneri isolated from tehran by a 120 kda protein band by sds-page, electron microscopy of cell culture and congo red dye methods. | 2007 | 18051704 |
| structural insights into the enzymatic mechanism of the pathogenic mapk phosphothreonine lyase. | the ospf family of phosphothreonine lyase, including spvc from salmonella, irreversibly inactivates the dual-phosphorylated host mapks (pt-x-py) through beta elimination. we determined crystal structures of spvc and its complex with a phosphopeptide substrate. spvc adopts a unique fold of alpha/beta type. the disordered n terminus harbors a canonical d motif for mapk substrate docking. the enzyme-substrate complex structure indicates that recognition of the phosphotyrosine followed by insertion ... | 2007 | 18060821 |
| [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 |
| systemic pharmacokinetics of rifaximin in volunteers with shigellosis. | rifaximin is an oral antibiotic indicated for treatment of traveler's diarrhea. rifaximin pharmacokinetics were evaluated in individuals challenged with shigella flexneri. peak plasma rifaximin concentrations were low after nine consecutive doses, and no accumulation was observed. rifaximin serum levels were minimal and similar to those previously reported in studies of healthy volunteers. | 2008 | 18086855 |
| antimicrobial susceptibility of shigella flexneri and s. dysenteriae isolated from stool specimens of patients with bloody diarrhoea in mwanza, tanzania. | this study was conducted to determine frequency and pattern of antimicrobial susceptibility of shigella species isolated from stool specimens collected from patients presenting with bloody diarrhoea in mwanza city, tanzania. the study was carried out from october 2004 to october 2005 and involved patients attending sekou toure regional hospital and butimba health centre. bacteriological cultures were done at the national institute for medical research laboratory. a total of 489 patients (median ... | 2007 | 18087897 |
| phenotypic and molecular characterization of tem-116 extended-spectrum beta-lactamase produced by a shigella flexneri clinical isolate from chickens. | extended-spectrum beta-lactamases (esbls) produced by a clinical isolate of shigella flexneri from chickens were detected with confirmatory phenotypic tests of the clinical and laboratory standards institute, and minimum inhibitory concentrations of several antibacterial drugs against the isolate were determined by the twofold dilution method. the genotype and subtype of the esbl-producing s. flexneri isolate were identified by pcr amplifying of esbl genes and dna sequencing analysis. the result ... | 2008 | 18093137 |
| effect of hand wash agents on controlling the transmission of pathogenic bacteria from hands to food. | the goals of this study were to evaluate the effectiveness of two hand wash regimens in reducing transient bacteria on the skin following a single hand wash and the subsequent transfer of the bacteria to a ready-to-eat food item, freshly cut cantaloupe melon. the number of bacteria recovered from hands and the quantity transferred to the melon were significantly less following the use of an antibacterial soap compared with plain soap. the antimicrobial soap achieved > 3-log reductions versus esc ... | 2007 | 18095447 |
| [type-determination of shigella paradysenteriae (flexner) and how to distinguish them from similar bacteria]. | | 1948 | 18126933 |
| a new type of phase variation in the 103 race of shigella paradysenteriae. | | 1949 | 18127625 |
| a field trial of shigella flexneri iii vaccine; serum agglutination studies. | | 1949 | 18137145 |
| identification of the nadler type (r. ettinger-tulczinska, 1943) with shigella sp. q 1167 (large-sachs) and the presence of shigella paradysenteriae boyd iii & v (flexner xi & xiii) in israel. | | 1949 | 18145345 |
| field trial of shigella flexneri iii vaccine; background, scope, and organization of the program. | | 1949 | 18146106 |
| direct detection of shigella flexneri and salmonella typhimurium in human feces by real-time pcr. | we have established a sybr green-based realtime pcr method using anydirect solution, which enhances pcr from whole blood, for direct amplification of the vira gene of shigella flexneri and the inva gene of salmonella typhimurium from human feces without prior dna purification. when we compared the efficiency of conventional or realtime pcr amplification of the vira and inva genes from the supernatant of boiled feces supplemented with s. flexneri and s. typhimurium in the presence or absence of a ... | 2007 | 18156776 |
| full structural characterization of shigella flexneri m90t serotype 5 wild-type r-lps and its delta galu mutant: glycine residue location in the inner core of the lipopolysaccharide. | shigella flexneri is a gram-negative bacterium responsible for serious enteric infections that occur mainly in the terminal ileum and colon. high interest in shigella, as a human pathogen, is driven by its antibiotic resistance and the necessity to develop a vaccine against its infections. vaccines of the last generation use carbohydrate moieties of the lipopolysaccharide as probable candidates. for this reason, the primary structure of the core oligosaccharide from the r-lps produced by s. flex ... | 2008 | 18174310 |
| ph sensitivity of type iii secretion system tip proteins. | many pathogenic gram-negative bacteria employ type iii secretion systems to transport proteins into the host cell membrane and cytoplasm to subvert normal cellular functions. the type iii secretion apparatus consists of a basal body spanning the inner and outer bacterial membranes and a needle which extends away from the bacterium. recent work has found that a special class of proteins localizes to the tip of the needle to control secretion of effector proteins. five of these tip proteins are ip ... | 2008 | 18175320 |
| 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 |
| death from multi-resistant shigelloses: a case study from fiji. | death from shigellosis is rare in developed countries, however it causes over a million deaths in developing countries worldwide annually. death from shigellosis is rare in fiji. however, the global problem of emerging multi-drug resistance raises some issues about the management of shigellosis in this country. within fiji, shigella is a notifiable disease. the fiji ministry of health recorded 68 cases of shigella in 1996, 173 cases in 1997 and 334 cases in 1998 (no data available for 1999). the ... | 2006 | 18181399 |
| cytoplasmic targeting of ipac to the bacterial pole directs polar type iii secretion in shigella. | type iii secretion (t3s) systems are largely used by pathogenic gram-negative bacteria to inject multiple effectors into eukaryotic cells. upon cell contact, these bacterial microinjection devices insert two t3s substrates into host cell membranes, forming a so-called 'translocon' that is required for targeting of type iii effectors in the cell cytosol. here, we show that secretion of the translocon component ipac of invasive shigella occurs at the level of one bacterial pole during cell invasio ... | 2008 | 18188151 |
| bacterial actin assembly requires toca-1 to relieve n-wasp autoinhibition. | actin polymerization in the mammalian cytosol can be locally activated by mechanisms that relieve the autoinhibited state of n-wasp, an initiator of actin assembly, a process that also requires the protein toca-1. several pathogenic bacteria, including shigella, exploit this host feature to infect and disseminate efficiently. the shigella outer membrane protein icsa recruits n-wasp, which upon activation at the bacterial surface mediates localized actin polymerization. the molecular role of toca ... | 2008 | 18191793 |
| the chaperone ipgc copurifies with the virulence regulator mxie. | the expression of a subset of shigella flexneri virulence genes is dependent upon a cytoplasmic chaperone, ipgc, and an activator from the arac/xyls family, mxie. in this paper, we report that the chaperone forms a specific and stable heteromer with mxie. | 2008 | 18192384 |
| role and regulation of iron-sulfur cluster biosynthesis genes in shigella flexneri virulence. | shigella flexneri, a causative agent of bacterial dysentery, possesses two predicted iron-sulfur cluster biosynthesis systems called suf and isc. s. flexneri strains containing deletion mutations in the entire suf operon (ur011) or the iscsua genes (ur022) were constructed. both mutants were defective in surviving exposure to oxidative stress. the suf mutant showed growth that was comparable to that of the parental strain in both iron-replete and iron-limiting media; however, the isc mutant show ... | 2008 | 18195027 |
| molecular pathogenesis of shigella spp.: controlling host cell signaling, invasion, and death by type iii secretion. | shigella spp. are gram-negative pathogenic bacteria that evolved from harmless enterobacterial relatives and may cause devastating diarrhea upon ingestion. research performed over the last 25 years revealed that a type iii secretion system (t3ss) encoded on a large plasmid is a key virulence factor of shigella flexneri. the t3ss determines the interactions of s. flexneri with intestinal cells by consecutively translocating two sets of effector proteins into the target cells. thus, s. flexneri co ... | 2008 | 18202440 |
| phase 1 clinical trial of live attenuated shigella dysenteriae type-1 deltaicsa deltaent deltafep deltastxa:hgr oral vaccine sc599 in healthy human adult volunteers. | twenty-eight adults received between 10(2) and 10(8)colony forming units of live shigella dysenteriae type-1 vaccine sc599, attenuated by deletion of invasion (icsa), iron chelation (ent, fep) and shiga toxin a-subunit (stxa) genes, followed by ciprofloxacin on day 4. dose-independent diarrhea or change in bowel habit was seen in 3 subjects, without dysentery, vaccinaemia or serious adverse events. hematology and biochemical parameters were unchanged. doses of 10(5) or greater induced dose-indep ... | 2008 | 18207287 |
| [antimicrobial effect of 4-(adamantyl-1)-1-(1-aminobutyl)benzol]. | antimicrobial activity in vitro of adamantine derivative in respect of aerobic and anaerobic microorganisms has been studied. in these conditions gram-positive bacteria and some representatives of gram-negative microorganisms (shigella flexneri, s. newvcastle, enterobacter aerogenes etc.) had maximal sensitivity (mic 0.6-5.0 and 0.1-5.0 mg/ml, respectively). pseudomonas aeruginosa were resistant to this substance (mic >1 mg/ml). | 2007 | 18217353 |
| regulation of expression and secretion of nleh, a new non-locus of enterocyte effacement-encoded effector in citrobacter rodentium. | together with enterohemorrhagic escherichia coli and enteropathogenic escherichia coli, citrobacter rodentium is a member of the attaching-and-effacing (a/e) family of bacterial pathogens. a/e pathogens use a type iii secretion system (t3ss) to translocate an assortment of effector proteins, encoded both within and outside the locus of enterocyte effacement (lee), into the colonized host cell, leading to the formation of a/e lesions and disease. here we report the identification and characteriza ... | 2008 | 18223087 |
| cmy-2-type plasmid-mediated ampc beta-lactamase finally emerging in argentina. | | 2008 | 18242960 |
| on-line monitoring of microbial volatile metabolites by proton transfer reaction-mass spectrometry. | a method for analysis of volatile organic compounds (vocs) from microbial cultures was established using proton transfer reaction-mass spectrometry (ptr-ms). a newly developed sampling system was coupled to a ptr-ms instrument to allow on-line monitoring of vocs in the dynamic headspaces of microbial cultures. the novel ptr-ms method was evaluated for four reference organisms: escherichia coli, shigella flexneri, salmonella enterica, and candida tropicalis. headspace vocs in sampling bottles con ... | 2008 | 18245241 |
| extracellular-loop peptide antibodies reveal a predominant hemichannel organization of connexins in polarized intestinal cells. | shigella, the causative agent of bacillary dysentery, invades colonic epithelial cells to elicit an intense inflammatory reaction leading to destruction of the mucosa. atp-dependent paracrine signalling induced by connexin (cx) hemichannel opening was previously shown to favor shigella flexneri invasion and dissemination in transfectants of hela cells [g. tran van nhieu, c. clair, r. bruzzone, m. mesnil, p. sansonetti and l. combettes. (2003). connexin-dependent intercellular communication incre ... | 2008 | 18267319 |
| 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 |
| distribution and antibiotic susceptibility of shigella isolates in bangui, central african republic. | we conducted a prospective study in four urban health care centres between january 2004 and november 2005 to determine the distribution and susceptibility patterns of shigella strains causing invasive diarrhoea in bangui, central african republic. of the 155 shigella isolated, shigella flexneri (51%) and shigella dysenteriae (30%) were the most common and the most resistant to usual antibiotics, including amoxicillin, sulphamethoxazole-trimethoprim and chloramphenicol. though multi-drug resistan ... | 2008 | 18282240 |
| the shf gene of a shigella flexneri homologue on the virulent plasmid paa2 of enteroaggregative escherichia coli 042 is required for firm biofilm formation. | enteroaggregative escherichia coli (eaec) is an increasingly important cause of diarrhea in both developing and industrialized countries, and is characterized by strong biofilm formation on the intestinal mucosa. sequencing of the virulent plasmid paa2 of the prototype eaec 042 revealed a cluster of three open reading frames (orfs; shf, capu, and virk) ca. 93% identical to a similar cluster located in shigella flexneri. the function of the first orf shf protein is not known, but the closest well ... | 2008 | 18293034 |
| terpenoid compositions, and antioxidant and antimicrobial properties of the rhizome essential oils of different hedychium species. | a phytochemical study of the rhizome essential oils of four different hedychium species was performed by means of gc and gc/ms analyses. h. ellipticum mainly contained 1,8-cineole, sabinene, and terpin-4-ol, while h. aurantiacum possessed terpin-4-ol, para-cymene, and bornyl acetate as the major entities. similarly, trans-meta-mentha-2,8-diene and linalool were noticed in h. coronarium. three different collections (i-iii) of h. spicatum showed amazing differences in the relative contents of thei ... | 2008 | 18293443 |
| single residue determines the specificity of neutrophil elastase for shigella virulence factors. | human neutrophil elastase (ne) is a key host defense protease that cleaves virulence factors of gram-negative bacteria. ne and cathepsin g (cg) are chymotrypsin-like serine proteases with sequence and structural similarities, and both are abundant in neutrophil granules. unlike ne, cg does not cleave virulence factors of enteric bacteria. through structure-function analysis, we identified regions in ne that are essential for cleaving shigella virulence proteins. ne residues at eight different po ... | 2008 | 18295791 |
| geographic analysis of shigellosis in vietnam. | geographic and ecological analysis may provide investigators useful ecological information for the control of shigellosis. this paper provides distribution of individual shigella species in space, and ecological covariates for shigellosis in nha trang, vietnam. data on shigellosis in neighborhoods were used to identify ecological covariates. a bayesian hierarchical model was used to obtain joint posterior distribution of model parameters and to construct smoothed risk maps for shigellosis. neigh ... | 2008 | 18296100 |
| structures of the shigella flexneri type 3 secretion system protein mxic reveal conformational variability amongst homologues. | many gram-negative pathogenic bacteria use a complex macromolecular machine, known as the type 3 secretion system (t3ss), to transfer virulence proteins into host cells. the t3ss is composed of a cytoplasmic bulb, a basal body spanning the inner and outer bacterial membranes, and an extracellular needle. secretion is regulated by both cytoplasmic and inner membrane proteins that must respond to specific signals in order to ensure that virulence proteins are not secreted before contact with a euk ... | 2008 | 18304577 |
| ipgb1 and ipgb2, two homologous effectors secreted via the mxi-spa type iii secretion apparatus, cooperate to mediate polarized cell invasion and inflammatory potential of shigella flexenri. | type iii secretion systems (t3ss) are present in many pathogenic gram-negative bacteria and mediate the translocation of bacterial effector proteins into host cells. here, we report the phenotypic characterization of s. flexneri ipgb1 and ipgb2 mutants, in which the genes encoding the ipgb1 and ipgb2 effectors have been inactivated, either independently or simultaneously. like ipgb1, we found that ipgb2 is secreted by the t3ss and its secretion requires the spa15 chaperone. upon infection of sem ... | 2008 | 18316224 |
| delivery of biologically active anti-inflammatory cytokines il-10 and il-1ra in vivo by the shigella type iii secretion apparatus. | pathogenicity of many gram-negative bacteria relies on a type iii secretion (t3s) apparatus, which is used for delivery of bacterial effectors into the host cell cytoplasm allowing the bacteria to manipulate host cell cytoskeleton network as well as to interfere with intracellular signaling pathways. in this study, we investigated the potential of the shigella flexneri t3sa as an in vivo delivery system for biologically active molecules such as cytokines. the anti-inflammatory cytokines il-10 an ... | 2008 | 18322242 |
| impact of infections and normal flora in nonhuman primates on drug development. | preclinical safety studies that are required for the marketing approval of a pharmaceutical include single and repeat dose studies in rodent and nonrodent species. the use of nonhuman primates (nhps), primarily macaques, as the nonrodent species has increased in recent years, in part due to the increase in development of biopharmaceuticals and immunomodulatory agents. depending on the source of the macaques, they may vary in genetic background, normal flora, and/or the incidence of preexisting p ... | 2008 | 18323580 |
| cold shock exoribonuclease r (vacb) is involved in aeromonas hydrophila pathogenesis. | in this study, we cloned and sequenced a virulence-associated gene (vacb) from a clinical isolate ssu of aeromonas hydrophila. we identified this gene based on our recently annotated genome sequence of the environmental isolate atcc 7966(t) of a. hydrophila and the vacb gene of shigella flexneri. the a. hydrophila vacb protein contained 798 amino acid residues, had a molecular mass of 90.5 kda, and exhibited an exoribonuclease (rnase r) activity. the rnase r of a. hydrophila was a cold-shock pro ... | 2008 | 18344363 |
| maturation of paneth cells induces the refractory state of newborn mice to shigella infection. | the intestinal tract of adult mice is naturally resistant to infection by shigella, the causative agent of bacillary dysentery in humans. conversely, newborn mice are highly susceptible to intragastric shigella infection and develop inflammatory lesions of the jejunal mucosa, very similar to those observed in the colon of dysenteric patients. however, the susceptibility period is short and one week after birth, animals have acquired a status of resistance characteristic of adult animals. to iden ... | 2008 | 18354217 |
| differential expression of ompc and ompf in multidrug-resistant shigella dysenteriae and shigella flexneri by aqueous extract of aegle marmelos, altering its susceptibility toward beta-lactam antibiotics. | steadily increasing resistance among shigella to beta-lactams, aminoglycosides, and tetracycline has compromised the utility of these commonly used antimicrobial agents. also, undesirable side effects of certain antibiotics have triggered immense interest in search of alternative therapies using medicinal plants. one such medicinal plant used since ancient times to cure diarrhea is aegle marmelos. the present study exemplifies the susceptibility of beta-lactam-resistant shigella dysenteriae and ... | 2008 | 18358664 |
| differential regulation by magnesium of the two msbb paralogs of shigella flexneri. | shigella flexneri, a gram-negative enteric pathogen, is unusual in that it contains two nonredundant paralogous genes that encode the myristoyl transferase msbb (lpxm) that catalyzes the final step in the synthesis of the lipid a moiety of lipopolysaccharide. msbb1 is encoded on the chromosome, and msbb2 is encoded on the large virulence plasmid present in all pathogenic shigellae. we demonstrate that myristoyl transferase activity due to msbb2 is detected in limited magnesium medium, but not in ... | 2008 | 18359815 |