Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
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| serine protease autotransporters from shigella flexneri and pathogenic escherichia coli target a broad range of leukocyte glycoproteins. | the serine protease autotransporters of enterobacteriaceae (spates) are secreted by pathogenic gram-negative bacteria through the autotransporter pathway. we previously classified spate proteins into two classes: cytotoxic (class 1) and noncytotoxic (class 2). here, we show that pic, a class 2 spate protein produced by shigella flexneri 2a, uropathogenic and enteroaggregative escherichia coli strains, targets a broad range of human leukocyte adhesion proteins. substrate specificity was restricte ... | 2011 | 21768350 |
| lipopolysaccharide core structures and their correlation with genetic groupings of shigella strains; a novel core variant in shigella boydii type 16. | bacteria shigella, the cause of shigellosis, evolved from intestinal bacteria escherichia coli. based on structurally diverse o-specific polysaccharide chains of the lipopolysaccharides (o-antigens), three from four shigella species are subdivided into multiple serotypes. the central oligosaccharide of the lipopolysaccharide called core is usually conserved within genus but five core types called r1-r4 and k-12 have been recognized in e. coli. structural data on the shigella core are limited to ... | 2011 | 21752864 |
| espg of enteropathogenic and enterohemorrhagic e. coli binds the golgi matrix protein gm130 and disrupts the golgi structure and function. | the enteric pathogens enteropathogenic escherichia coli (epec), enterohaemorrhagic e. coli (ehec) and shigella flexneri all translocate at least one effector protein of the espg protein family into host cells via a type iii secretion system (t3ss). the espg family comprises espg, espg2 and vira. from a y2h screen, we identified the golgi matrix protein gm130 as a potential binding partner of espg. we confirmed espg:gm130 protein interaction by affinity co-purification. in co-immunoprecipitation ... | 2011 | 21740499 |
| structural and functional studies on the n-terminal domain of the shigella type iii secretion protein mxig. | mxig is a single-pass membrane protein that oligomerizes within the inner membrane ring of the shigella flexneri type iii secretion system (t3ss). the mxig n-terminal domain (mxig-n) is the predominant cytoplasmic structure; however, its role in t3ss assembly and secretion is largely uncharacterized. we have determined the solution structure of mxig-n residues 6-112 (mxig-n(6-112)), representing the first published structure of this t3ss domain. the structure shows strong structural homology to ... | 2011 | 21733840 |
| a multifactor regulatory circuit involving h-ns, virf and an antisense rna modulates transcription of the virulence gene icsa of shigella flexneri. | the icsa gene of shigella encodes a structural protein involved in colonization of the intestinal mucosa by bacteria. this gene is expressed upon invasion of the host and is controlled by a complex regulatory circuit involving the nucleoid protein h-ns, the arac-like transcriptional activator virf, and a 450ôçënt antisense rna (rnag) acting as transcriptional attenuator. we investigated on the interplay of these factors at the molecular level. dnase i footprints reveal that both h-ns and virf bi ... | 2011 | 21724612 |
| studies on the activity of cyperus rotundus linn. tubers against infectious diarrhea. | to study the antidiarrheal activity of the decoction of cyperus rotundus linn. tubers using representative assays of diarrheal pathogenesis and understand its mechanism of action.antibacterial, antigiardial and antirotaviral activities were studied. effect on adherence of enteropathogenic escherichia coli (epec) and invasion of enteroinvasive e. coli (eiec) and shigella flexneri to hep-2 cells was evaluated as a measure of effect on colonization. effect on enterotoxins such as enterotoxigenic e. ... | 2011 | 21713044 |
| atomic structure of bacteriophage sf6 tail needle knob. | podoviridae are double-stranded dna bacteriophages that use short, non-contractile tails to adsorb to the host cell surface. within the tail apparatus of p22-like phages, a dedicated fiber known as the "tail needle" likely functions as a cell envelope-penetrating device to promote ejection of viral dna inside the host. in sf6, a p22-like phage that infects shigella flexneri, the tail needle presents a c-terminal globular knob. this knob, absent in phage p22 but shared in other members of the p22 ... | 2011 | 21705802 |
| antibacterial dimeric copper(ii) complexes with chromone-derived compounds. | a new series of six chromone-derived compounds and their cu(ii) complexes have been synthesized and characterized by their physical, spectral and analytical data. the ligands and their cu(ii) complexes were screened for their in vitro antibacterial activity against four gram-negative (escherichia coli, pseudomonas aeruginosa, salmonella typhi, shigella flexneri) and two gram-positive (bacillus subtilis, staphylococcus aureus) bacterial strains by agar-well diffusion method. the ligands were foun ... | 2011 | 21699463 |
| comparative sequence analysis of acid sensitive/resistance proteins in escherichia coli and shigella flexneri. | the molecular basis for the survival of bacteria under extreme conditions in which growth is inhibited is a question of great current interest. a preliminary study was carried out to determine residue pattern conservation among the antiporters of enteric bacteria, responsible for extreme acid sensitivity especially in escherichia coli and shigella flexneri. here we found the molecular evidence that proved the relationship between e. coli and s. flexneri. multiple sequence alignment of the gadc c ... | 2007 | 21670792 |
| genetic characteristics and changing antimicrobial resistance among shigella spp isolated from hospitalized diarrhoeal patients in kolkata, india. | to study the prevalence pattern and trends in the phenotypic and genetic characteristics of shigellae, we tested 212 isolates isolated from diarrhoeal patients admitted at the infectious diseases hospital, kolkata, india from november 2007 to october 2009. prevalence of shigella spp was more in more than 5 years age group (69%) than the children >5 years age group (31%). serotypes 2a, 3a and untypable isolates of the subtype s. flexneri were frequently detected. increase in the isolation of s. s ... | 2011 | 21659504 |
| modulation of connexin signaling by bacterial pathogens and their toxins. | inherent to their pivotal tasks in the maintenance of cellular homeostasis, gap junctions, connexin hemichannels, and pannexin hemichannels are frequently involved in the dysregulation of this critical balance. the present paper specifically focuses on their roles in bacterial infection and disease. in particular, the reported biological outcome of clinically important bacteria including escherichia coli, shigella flexneri, yersinia enterocolitica, helicobacter pylori, bordetella pertussis, aggr ... | 2011 | 21656255 |
| gisul2, a genomic island carrying the sul2 sulphonamide resistance gene and the small mobile element cr2 found in the enterobacter cloacae subspecies cloacae type strain atcc 13047 from 1890, shigella flexneri atcc 700930 from 1954 and acinetobacter baumannii atcc 17978 from 1951. | 2011 | 21653606 | |
| p62 and ndp52 target intracytosolic shigella and listeria to different autophagy pathways. | autophagy is an important mechanism of innate immune defense. we have recently shown that autophagy components are recruited with septins, a new and increasingly characterized cytoskeleton component, to intracytosolic shigella that have started to polymerize actin. on the other hand, intracytosolic listeria avoids autophagy recognition by expressing acta, a bacterial effector required for actin polymerization. here we exploit shigella and listeria as intracytosolic tools to characterize differen ... | 2011 | 21646350 |
| production of bioactive sheep β-defensin-1 in pichia pastoris. | previous research has shown that sheep β-defensin-1 (sbd-1), a small cationic peptide with a broad range of antimicrobial activities, could inhibit the growth of both gram-positive and gram-negative bacteria as well as that of fungi. in order to increase the yield of current ovine defensin purification methods, mature sbd-1 (msbd-1) was added with a 6-his tag on the c-terminus (msbd-1-t) and expressed in pichia pastoris in the presented work. the msbd-1 and msbd-1-t were expressed in the pichia ... | 2011 | 21643707 |
| structure-guided investigation of lipopolysaccharide o-antigen chain length regulators reveals regions critical for modal length control. | the o-antigen component of the lipopolysaccharide (lps) represents a population of polysaccharide molecules with a non-random (modal) chain length distribution. the number of the repeat o-units in each individual o-antigen polymer depends on the wzz chain-length regulator, an inner membrane protein belonging to the polysaccharide co-polymerase (pcps) family. different wzz proteins confer vastly different ranges of modal lengths (4 to >100 repeat units) despite having remarkably conserved structu ... | 2011 | 21642455 |
| synthesis, characterization and biological properties of thienyl derived triazole schiff bases and their oxovanadium(iv) complexes. | a new series of biologically active thienyl derived triazole schiff bases and their oxovanadium(iv) complexes have been synthesized and characterized on the basis of physical (m.p., magnetic susceptibility and conductivity), spectral (ir, (1)h and (13)c nmr, electronic and mass spectrometry) and microanalytical data. all the schiff base ligands and their oxovanadium(iv) complexes have been subjected to in vitro antibacterial activity against four gram-negative (escherichia coli, shigella flexner ... | 2011 | 21635212 |
| complete (1)h and (13)c nmr chemical shift assignments of mono-, di-, and trisaccharides as basis for nmr chemical shift predictions of polysaccharides using the computer program casper. | the computer program casper uses (1)h and (13)c nmr chemical shift data of mono- to trisaccharides for the prediction of chemical shifts of oligo- and polysaccharides. in order to improve the quality of these predictions the (1)h and (13)c, as well as (31)p when applicable, nmr chemical shifts of 30 mono-, di-, and trisaccharides were assigned. the reducing sugars gave two distinct sets of nmr resonances due to the α- and β-anomeric forms. in total 35 (1)h and (13)c nmr chemical shift data sets ... | 2011 | 21621752 |
| a novel compound from the marine bacterium bacillus pumilus s6-15 inhibits biofilm formation in gram-positive and gram-negative species. | biofilm formation is a critical problem in nosocomial infections and in the aquaculture industries and biofilms show high resistance to antibiotics. the aim of the present study was to reveal a novel anti-biofilm compound from marine bacteria against antibiotic resistant gram-positive and gram-negative biofilms. the bacterial extract (50 μg ml(-1)) of s6-01 (bacillus indicus = mtcc 5559) showed 80-90% biofilm inhibition against escherichia coli, shigella flexneri, proteus mirabilis and s6-15 (ba ... | 2011 | 21614700 |
| identification of small-molecule inhibitors of yersinia pestis type iii secretion system yscn atpase. | yersinia pestis is a gram negative zoonotic pathogen responsible for causing bubonic and pneumonic plague in humans. the pathogen uses a type iii secretion system (t3ss) to deliver virulence factors directly from bacterium into host mammalian cells. the system contains a single atpase, yscn, necessary for delivery of virulence factors. in this work, we show that deletion of the catalytic domain of the yscn gene in y. pestis co92 attenuated the strain over three million-fold in the swiss-webster ... | 2011 | 21611119 |
| dynamic aspects of antibody:oligosaccharide complexes characterized by molecular dynamics simulations and std-nmr. | carbohydrates are likely to maintain significant conformational flexibility in antibody:carbohydrate complexes. as demonstrated herein for the protective monoclonal antibody f22-4 recognizing the shigella flexneri 2a o-antigen and numerous synthetic oligosaccharide fragments thereof, the combination of molecular dynamics simulations and nmr saturation transfer difference experiments, supported by physicochemical analysis, allows to determine the binding epitope and its various contributions to a ... | 2011 | 21610193 |
| transient suppression of shigella flexneri type 3 secretion by a protective o-antigen-specific monoclonal iga. | abstract mucosal immunity to the enteric pathogen shigella flexneri is mediated by secretory iga (s-iga) antibodies directed against the o-antigen (o-ag) side chain of lipopolysaccharide. while secretory antibodies against the o-ag are known to prevent bacterial invasion of the intestinal epithelium, the mechanisms by which this occurs are not fully understood. in this study, we report that the binding of a murine monoclonal iga (igac5) to the o-ag of s. flexneri serotype 5a suppresses activity ... | 2011 | 21610121 |
| development of a new guinea-pig model of shigellosis. | shigellosis is a major form of bacillary dysentery caused by shigella spp. to date, there is no suitable animal model to evaluate the protective efficacy of vaccine candidates against this pathogen. here, we describe a successful experimental shigellosis in the guinea-pig model, which has shown the characteristic features of human shigellosis. this model yielded reproducible results without any preparatory treatment besides cecal ligation. in this study, guinea-pigs were discretely infected with ... | 2011 | 21539623 |
| rapid situation & response assessment of diarrhoea outbreak in a coastal district following tropical cyclone aila in india. | background & objectives : cyclone aila hit indian states on eastern coast on may 25, 2009. an investigation was conducted to examine if aila was responsible for increased reporting of diarrhoea cases from the district of east-medinipur in west bengal. identifying causative organisms for diarrhoea and assessing their antibiotic susceptibility profile were other objectives. methods: rapid situation and response assessment technique was employed to triangulate primary and secondary data collected t ... | 2011 | 21537092 |
| synthesis, characterization and biological studies of sulfonamide schiff's bases and some of their metal derivatives. | a new series of schiff base ligands derived from sulfonamide and their metal(ii) complexes [cobalt(ii), copper(ii), nickel(ii) and zinc(ii)] have been synthesized and characterized. the nature of bonding and structure of all the synthesized compounds has been explored by physical, analytical and spectral data of the ligands and their metal(ii) complexes. the authors suggest that all the prepared complexes possess an octahedral geometry. the ligands and metal(ii) complexes have been screened for ... | 2011 | 21534864 |
| a novel vinculin binding site of the ipaa invasin of shigella. | internalization of shigella into host epithelial cells, where the bacteria replicates and spreads to neighboring cells, requires a type 3 secretion system (t3ss) effector coined ipaa. ipaa binds directly to and activates the cytoskeletal protein vinculin after injection in the host cell cytosol and heretofore this was thought to be directed by two amphipathic α-helical vinculin binding sites (vbs) found in the c-terminal tail domain of ipaa. here we report a third vbs, ipaa-vbs3, that is located ... | 2011 | 21525010 |
| evaluation of low-copy genetic targets for waterborne bacterial pathogen detection via qpcr. | recent developments in water quality research have highlighted difficulties in accurately predicting the incidence of pathogens within freshwater based on the viability, culturability and metabolic activity of indicator organisms. qpcr-driven assays are candidates to replace standard culture-based methods, however, protocols suitable for routine use have yet to be sufficiently validated. the objective of this study was to evaluate five oligonucleotide primers sets (etir, sinv, exot, vs1 and ipah ... | 2011 | 21514618 |
| enteric virulence associated protein vapc inhibits translation by cleavage of initiator trna. | eukaryotic pin (pilt n-terminal) domain proteins are ribonucleases involved in quality control, metabolism and maturation of mrna and rrna. the majority of prokaryotic pin-domain proteins are encoded by the abundant vapbc toxin-antitoxin loci and inhibit translation by an unknown mechanism. here we show that enteric vapcs are site-specific endonucleases that cleave trna(fmet) in the anticodon stem-loop between nucleotides +38 and +39 in vivo and in vitro. consistently, vapc inhibited translation ... | 2011 | 21502523 |
| the shigella flexneri type three secretion system effector ipgd inhibits t cell migration by manipulating host phosphoinositide metabolism. | shigella, the gram-negative enteroinvasive bacterium that causes shigellosis, relies on its type iii secretion system (ttss) and injected effectors to modulate host cell functions. however, consequences of the interaction between shigella and lymphocytes have not been investigated. we show that shigella invades activated human cd4(+) t lymphocytes. invasion requires a functional ttss and results in inhibition of chemokine-induced t cell migration, an effect mediated by the ttss effector ipgd, a ... | 2011 | 21501826 |
| an integrated approach for finding overlooked genes in shigella. | the completion of numerous genome sequences introduced an era of whole-genome study. however, many genes are missed during genome annotation, including small rnas (srnas) and small open reading frames (sorfs). in order to improve genome annotation, we aimed to identify novel srnas and sorfs in shigella, the principal etiologic agents of bacillary dysentery. | 2011 | 21483688 |
| behavior of salmonella typhimurium, staphylococcus aureus, listeria monocytogenes, and shigella flexneri and shigella sonnei during production of pulque, a traditional mexican beverage. | pulque is a typical fermented alcoholic beverage of central mexico, produced from the nectar of maguey agave plants. production systems are largely artisanal, with inadequate hygiene conditions and exposure to multiple contamination sources. no data exist on pulque microbiological safety and the behavior of pathogenic microorganisms in agave nectar and pulque. an initial trial was done of the behavior of salmonella typhimurium, staphylococcus aureus, listeria monocytogenes, and shigella flexneri ... | 2011 | 21477472 |
| vinculin activators target integrins from within the cell to increase melanoma sensitivity to chemotherapy. | metastatic melanoma is an aggressive skin disease for which there are no effective therapies. emerging evidence indicates that melanomas can be sensitized to chemotherapy by increasing integrin function. current integrin therapies work by targeting the extracellular domain, resulting in complete gains or losses of integrin function that lead to mechanism-based toxicities. an attractive alternative approach is to target proteins, such as vinculin, that associate with the integrin cytoplasmic doma ... | 2011 | 21460181 |
| evaluation of antidiarrheal and in vitro antiprotozoal activities of extracts of leaves of alocasia indica. | alocasia indica schott (araceae) is used in several regions of india, especially in rural communities, by traditional medicine practitioners to treat diarrhea. however, no scientific data are available to justify the traditional potentials of the plant species in gastrointestinal disorders. | 2011 | 21428863 |
| synthesis and in vitro microbiological evaluation of novel diethyl 6,6'-(1,4-phenylene)bis(4-aryl-2-oxo-cyclohex-3-enecarboxylates). | novel bis cyclohexenone ester derivatives 14-19 were synthesized and characterized by their spectral data. in vitro microbiological evaluations were carried out for all the novel compounds 14-19 against clinically isolated bacterial and fungal strains. compounds 15, 16, 18 against staphylococcus aureus, 14, 15 against ß-haemolytic streptococcus, 15, 19 against micrococcus luteus, 17, 18 against salmonella typhii, 14, 17 against shigella flexneri, 15 against escherichia coli, 16 against pseudomon ... | 2011 | 21417963 |
| shigella flexneri type iii secreted effector ospf reveals new crosstalks of proinflammatory signaling pathways during bacterial infection. | shigella flexneri type iii secreted effector ospf harbors a phosphothreonine lyase activity that irreversibly dephosphorylates map kinases (mapks) p38 and erk in infected epithelial cells and thereby, dampens innate immunity. whereas this activity has been well characterized, the impact of ospf on other host signaling pathways that control inflammation was unknown. here we report that ospf potentiates the activation of the mapk jnk and the transcription factor nf-?b during s. flexneri infection. ... | 2011 | 21402152 |
| structural elucidation of the o-antigen of the shigella flexneri provisional serotype 88-893: structural and serological similarities with s. flexneri provisional serotype y394 (1c). | the structure of the repeating unit of the o-antigen polysaccharide from shigella flexneri provisional serotype 88-893 has been determined. (1)h and (13)c nmr spectroscopy as well as 2d nmr experiments were employed to elucidate the structure. the carbohydrate part of the hexasaccharide repeating unit is identical to the previously elucidated structure of the o-polysaccharide from s. flexneri prov. serotype y394. the o-antigen of s. flexneri prov. serotype 88-893 carries 0.7 mol o-acetyl group p ... | 2011 | 21392735 |
| a candidate approach implicates the secreted salmonella effector protein spvb in p-body disassembly. | p-bodies are dynamic aggregates of rna and proteins involved in several post-transcriptional regulation processes. p-bodies have been shown to play important roles in regulating viral infection, whereas their interplay with bacterial pathogens, specifically intracellular bacteria that extensively manipulate host cell pathways, remains unknown. here, we report that salmonella infection induces p-body disassembly in a cell type-specific manner, and independently of previously characterized pathway ... | 2011 | 21390246 |
| antigen-specific iga b memory cell responses to shigella antigens elicited in volunteers immunized with live attenuated shigella flexneri 2a oral vaccine candidates. | we studied the induction of antigen-specific iga memory b cells (b(m)) in volunteers who received live attenuated shigella flexneri 2a vaccines. subjects ingested a single oral dose of 10(7), 10(8) or 10(9) cfu of s. flexneri 2a with deletions in guaba (cvd 1204) or in guaba, set and sen (cvd 1208). antigen-specific serum and stool antibody responses to lps and ipa b were measured on days 0, 7, 14, 28 and 42. iga b(m) cells specific to lps, ipa b and total iga were assessed on days 0 and 28. we ... | 2011 | 21388888 |
| ribonucleases and bacterial virulence. | bacterial stress responses provide them the opportunity to survive hostile environments, proliferate and potentially cause diseases in humans and animals. the way in which pathogenic bacteria interact with host immune cells triggers a complicated series of events that include rapid genetic re-programming in response to the various host conditions encountered. viewed in this light, the bacterial host-cell induced stress response (hcisr) is similar to any other well-characterized environmental str ... | 2010 | 21375713 |
| enterobacteriaceae associated with eggs of podocnemis expansa and podocnemis unifilis (testudines:chelonia) in nonpolluted sites of national park of araguaia plains, brazil. | fertile eggs of podocnemis expansa and podocnemis unifilis were investigated for the presence of enterobacteria, as these two endangered species have the potential for conservation measures that include egg transfer. knowledge of normal microflora associated with turtles and turtle eggs would help effectively manage the transfer of these eggs among institutions. thirty eggs of each species were collected, aseptically transferred, cracked inside plastic bags containing tetrathionate broth, and sp ... | 2010 | 21370647 |
| gadd45a activity is the principal effector of shigella mitochondria-dependent epithelial cell death in vitro and ex vivo. | modulation of death is a pathogen strategy to establish residence and promote survival in host cells and tissues. shigella spp. are human pathogens that invade colonic mucosa, where they provoke lesions caused by their ability to manipulate the host cell responses. shigella spp. induce various types of cell death in different cell populations. however, they are equally able to protect host cells from death. here, we have investigated on the molecular mechanisms and cell effectors governing the b ... | 2011 | 21368893 |
| antigen-specific cd8(+) t cells fail to respond to shigella flexneri. | cd8(+) t lymphocytes often play a primary role in adaptive immunity to cytosolic microbial pathogens. surprisingly, cd8(+) t cells are not required for protective immunity to the enteric pathogen shigella flexneri, despite the ability of shigella to actively secrete proteins into the host cytoplasm, a location from which antigenic peptides are processed for presentation to cd8(+) t cells. to determine why cd8(+) t cells fail to play a role in adaptive immunity to s. flexneri, we investigated whe ... | 2011 | 21357720 |
| rapid emergence of third-generation cephalosporin resistance in shigella sp. isolated in andaman and nicobar islands, india. | shigellosis is a major cause of diarrheal diseases among children in andaman & nicobar islands, india, which have a population of 350,000 people, including settlers from mainland india and 6 indigenous tribes. from the last one-and-half decade, we have been monitoring the species distribution and emergence of antibiotic resistance among the isolates of shigella. the circulating shigella strains have been found rapidly acquiring resistance to a wide spectrum of antibiotics. the recent data indica ... | 2011 | 21352076 |
| a comparison of disease caused by shigella and campylobacter species: 24 months community based surveillance in 4 slums of karachi, pakistan. | despite the efforts of the international community diarrheal diseases still pose a major threat to children in children less than five years of age. bacterial diarrhea has also emerged as a public health concern due to the proliferation of drug resistant species in many parts of the world. there is a paucity of population-based data about the incidence of shigellosis and campylobacter infections in pakistan. we report country specific results for shigella diarrhea that were derived from a multic ... | 2011 | 21338955 |
| methods for the preparation and crystallization of fab fragments in complex with peptide antigens derived from n. meningitidis outer membrane proteins. | an understanding of the molecular basis for the recognition of outer-membrane proteins (omps) by antibody is an important goal in the development of a more rational approach to vaccine design. x-ray crystallography has been outstandingly successful in delineating the detailed chemical interactions that are responsible for the high affinity and high selectivity of antibody-antigen interactions (1). although a number of x-ray structures of omps have now been reported (e.g., 2), determination of th ... | 2001 | 21336751 |
| crystal structure of the autochaperone region from the shigella flexneri autotransporter icsa. | the icsa (intracellular spread gene a) autotransporter from shigella flexneri is a key virulence factor. we identified a stable fragment comprising residues 591 to 758, which corresponds to the autochaperone region of the icsa passenger domain. we showed that thermal unfolding of the autochaperone region is reversible and determined its crystal structure at 2.0-å resolution. | 2011 | 21335457 |
| monitoring shigella flexneri vacuolar escape by flow cytometry. | invasive bacterial pathogens such as shigella flexneri force their uptake into non-phagocytic host cells. upon internalization, they rupture the endocytic vacuole and escape into the host cell cytoplasm. recent studies applying fluorescence resonance energy transfer (fret) based methods to track host-pathogen interactions have provided insights into the process of bacterial infection at the single cell level. we have previously reported that the vacuolar escape of invasive bacteria into the host ... | 2011 | 21317555 |
| synthesis, spectral analysis and in vitro microbiological evaluation of novel ethyl 4-(naphthalen-2-yl)-2-oxo-6-arylcyclohex-3-enecarboxylates and 4,5-dihydro-6-(napthalen-2-yl)-4-aryl-2h-indazol-3-ols. | a series of ethyl 4-(naphthalen-2-yl)-2-oxo-6-arylcyclohex-3-enecarboxylates 8-14 and 4,5-dihydro-6-(naphthalen-2-yl)-4-aryl-2h-indazol-3-ols 15-21 were synthesised and characterised by their spectroscopic data. in vitro microbiological evaluations were carried out for all the newly synthesised compounds 8-21 against clinically isolated bacterial and fungal strains. compounds 9, 12 and 20 against staphylococcus aureus, 10, 12, 20 against ß-haemolytic streptococcus, 11, 17 against bacillus subtil ... | 2011 | 21299432 |
| enteric glial cells: new players in mucosal defence against bacteria? | 2011 | 21282131 | |
| antibacterial, antifungal and cytotoxic activities of amblyone isolated from amorphophallus campanulatus. | to assess the in vitro antibacterial, antifungal and cytotoxic activities of amblyone, a triterpenoid isolated from amorphophallus campanulatus (roxb). | 2008 | 21264161 |
| ceftriaxone resistant shigella flexneri, an emerging problem. | shigellosis is a disease of public health importance in developing countries. it may cause self-limited diarrhea to severe dysentery. emergence of multi drug resistant (mdr) strains is a growing concern globally. ceftriaxone and ciprofloxacin are the drugs of choice for mdr cases. here, we report a case of mdr shigella flexneri from an immunocompromised patient. the strain was resistant to ceftriaxone [minimum inhibitory concentration (mic) ≥ 64 μg/ml], limiting the treatment option. simultaneou ... | 2010 | 21258157 |
| analysis of shigella flexneri-mediated infections in model organism caenorhabditis elegans. | shigella flexneri is the causative agent of bacillary dysentery and generates a significant global disease burden. the aim of this study was to analyze the pathogenesis and host immune response, at both the physiological and molecular level, using the model organism caenorhabditis elegans, in response to s. flexneri. c. elegans is a nematode that responds to infection with a simple innate immune system, key aspects of which have been shown to be conserved. | 2011 | 21254954 |
| two promoters and two translation start sites control the expression of the shigella flexneri outer membrane protease icsp. | the shigella flexneri outer membrane protease icsp proteolytically cleaves the actin-based motility protein icsa from the bacterial surface. the icsp gene is monocistronic and lies downstream of an unusually large intergenic region on the shigella virulence plasmid. in silico analysis of this region predicts a second transcription start site 84 bp upstream of the first. primer extension analyses and beta-galactosidase assays demonstrate that both transcription start sites are used. both promoter ... | 2011 | 21225241 |
| shigella enterotoxin-2 is a type iii effector that participates in shigella-induced interleukin 8 secretion by epithelial cells. | we have previously described a protein termed shigella enterotoxin 2 (shet-2), which induces rises in short-circuit current in rabbit ileum mounted in the ussing chamber. published reports have postulated that shet-2 may be secreted by the shigella type iii secretion system (t3ss). in this study, we show that shet-2 secretion into the extracellular space requires the t3ss in shigella flexneri 2a strain 2457t and a shet-2-tem fusion was translocated into epithelial cells in a t3ss-dependent manne ... | 2011 | 21219446 |
| volatile compounds and antimicrobial and antioxidant activities of the essential oils of the needles of pinus densiflora and pinus thunbergii. | to investigate the volatile compounds and the antibacterial and antioxidant effects of the essential oils of pinus densiflora needles (epdn) and pinus thunbergii needles (eptn), the volatile compounds of steam-distilled essential oils were analysed by gas chromatography-mass spectrometry. antibacterial activities were analysed by performing disc-agar diffusion assay and determining the minimum inhibitory concentrations (mics) of the essential oils. antioxidant activities were analysed via radica ... | 2011 | 21213230 |
| cutting edge: nlrc5-dependent activation of the inflammasome. | the nucleotide-binding domain leucine-rich repeat-containing proteins, nlrs, are intracellular sensors of pathogen-associated molecular patterns and damage-associated molecular patterns. a subgroup of nlrs can form inflammasome complexes, which facilitate the maturation of procaspase 1 to caspase 1, leading to il-1β and il-18 cleavage and secretion. nlrc5 is predominantly expressed in hematopoietic cells and has not been studied for inflammasome function. rna interference-mediated knockdown of n ... | 2010 | 21191067 |
| emergence of a novel shigella flexneri serotype 4s strain that evolved from a serotype x variant in china. | this paper describes the first isolation of a new shigella flexneri serotype, designated 4s, in beijing, china. genotypic and phenotypic profiling suggests that this isolate is a clone of the s. flexneri serotype x variant reference strain. of particular concern is the multidrug resistance exhibited by this isolate. | 2010 | 21177890 |
| [study on the integration site and arrangement of sfii and sfx prophages in shigella flexneri serotype 2b strains.] | objective: to study the integration site and arrangement of sfii and sfx prophages in shigella flexneri serotype 2b strains. methods: a series of primers were designed based on potential integration site of sfii and sfx prophages in shigella flexneri serotype 2b strains, and pcr were performed for 50 serotype 2b strains to amplify special genes located in host and prophages. pcr products were sequenced to identify integration sites and arrangement of sfii and sfx. results: in all the serotype 2b ... | 2010 | 21162847 |
| notes from the field: emergence of shigella flexneri 2a resistant to ceftriaxone and ciprofloxacin --- south carolina, october 2010. | on october 20, 2010, the south carolina department of health and environmental control and cdc began investigating a cluster of three diarrheal illnesses caused by multidrug-resistant shigella flexneri 2a. the index case occurred in a girl aged 2 years who experienced the onset of diarrhea on september 25 and was hospitalized the next day because of a seizure and fever. on september 30, her brother, aged 6 years, was hospitalized with vomiting, bloody diarrhea, and hyponatremia. three days later ... | 2010 | 21160457 |
| serotypes and extended-spectrum β-lactamase types of clinical isolates of shigella spp. from the zhejiang province of china. | to understand the distribution of the serotypes of shigella spp. and to investigate the drug-resistant genes of extended-spectrum β-lactamases (esbls) in shigella in zhejiang province, we have collected clinically isolated shigella isolates from 2 hospitals in zhejiang province during august to december of 2006. there are 11 shigella flexneri and 13 shigella sonnei isolates, respectively. among the 11 s. flexneri, 9 are serotype f4 and the remaining 2 are f1a and f2a. antimicrobial susceptibilit ... | 2011 | 21146721 |
| antimicrobial resistance patterns and prevalence of class 1 and 2 integrons in shigella flexneri and shigella sonnei isolated in uzbekistan. | abstract: | 2010 | 21143880 |
| the shigella t3ss needle transmits a signal for mxic release, which controls secretion of effectors. | type iii secretion systems (t3sss) are key determinants of virulence in many gram-negative bacteria, including animal and plant pathogens. they inject 'effector' proteins through a 'needle' protruding from the bacterial surface directly into eukaryotic cells after assembly of a 'translocator' pore in the host plasma membrane. secretion is a tightly regulated process, which is blocked until physical contact with a host cell takes place. host cell sensing occurs through a distal needle 'tip comple ... | 2010 | 21143311 |
| enteric glia protect against shigella flexneri invasion in intestinal epithelial cells: a role for s-nitrosoglutathione. | enteric glial cells (egcs) are important regulators of intestinal epithelial barrier (ieb) functions. egc-derived s-nitrosoglutathione (gsno) has been shown to regulate ieb permeability. whether egcs and gsno protect the ieb during infectious insult by pathogens such as shigella flexneri is not known. | 2010 | 21139062 |
| lactobacillus plantarum lipoteichoic acid down-regulated shigella flexneri peptidoglycan-induced inflammation. | bacterial peptidoglycans (pgns) are recognized by the host's innate immune system. this process is mediated by the nod/card family of proteins, which induces inflammation by activating nuclear factor (nf)-κb. excessive activation of monocytes by shigella flexneri pgn (flexpgn) leads to serious inflammatory diseases such as intestinal bowel diseases (ibd) and crohn's disease. in this study, we examined whether lactobacillus plantarum lipoteichoic acid (plta) could attenuate the pro-inflammatory s ... | 2010 | 21129777 |
| conformational changes in ipad from shigella flexneri upon binding bile salts provide insight into the second step of type iii secretion. | shigella flexneri uses its type iii secretion apparatus (ttsa) to inject host-altering proteins into targeted eukaryotic cells. the ttsa is composed of a basal body and an exposed needle with invasion plasmid antigen d (ipad) forming a tip complex that controls secretion. the bile salt deoxycholate (doc) stimulates recruitment of the translocator protein ipab into the maturing ttsa needle tip complex. this process appears to be triggered by a direct interaction between doc and ipad. fluorescence ... | 2010 | 21126091 |
| isolation and characterization of shigella flexneri g3, capable of effective cellulosic saccharification under mesophilic conditions. | a novel shigella strain (shigella flexneri g3) showing high cellulolytic activity under mesophilic, anaerobic conditions was isolated and characterized. the bacterium is gram negative, short rod shaped, and nonmotile and displays effective production of glucose, cellobiose, and other oligosaccharides from cellulose (avicel ph-101) under optimal conditions (40°c and ph 6.5). approximately 75% of the cellulose was hydrolyzed in modified atcc 1191 medium containing 0.3% cellulose, and the oligosacc ... | 2010 | 21097577 |
| cell-cell propagation of nf-κb transcription factor and map kinase activation amplifies innate immunity against bacterial infection. | the enteroinvasive bacterium shigella flexneri uses multiple secreted effector proteins to downregulate interleukin-8 (il-8) expression in infected epithelial cells. yet, massive il-8 secretion is observed in shigellosis. here we report a host mechanism of cell-cell communication that circumvents the effector proteins and strongly amplifies il-8 expression during bacterial infection. by monitoring proinflammatory signals at the single-cell level, we found that the activation of the transcription ... | 2010 | 21093316 |
| enteropathogenic e. coli non-lee encoded effectors nleh1 and nleh2 attenuate nf-κb activation. | enteric bacterial pathogens have evolved sophisticated strategies to evade host immune defences. some pathogens deliver anti-inflammatory effector molecules into the host cell cytoplasm via a type iii secretion system (t3ss). enteropathogenic escherichia coli (epec) inhibits inflammation by an undefined, t3ss-dependent mechanism. two proteins encoded outside of the epec locus of enterocyte effacement (lee) pathogenicity island, non-lee-encoded effector h1 (nleh1) and h2 (nleh2), display sequence ... | 2010 | 21091507 |
| extended-spectrum ß-lactamase production in shigella flexneri. | emergence of multidrug-resistant strains of shigella is a growing concern across the globe. third-generation cephalosporins are used for treating infections caused by multidrug-resistant shigellae. however, resistance to these cephalosporin antibiotics due to extended-spectrum ß-lactamases, has emerged as a new problem. so far extended-spectrum ß-lactamases producing shigella has not been reported from pakistan. we report such a case in shigella flexneri from an 8-year old girl with acute dysent ... | 2010 | 21078255 |
| entrapment of intracytosolic bacteria by septin cage-like structures. | actin-based motility is used by various pathogens for dissemination within and between cells. yet host factors restricting this process have not been identified. septins are gtp-binding proteins that assemble as filaments and are essential for cell division. however, their role during interphase has remained elusive. here, we report that septin assemblies are recruited to different bacteria that polymerize actin. we observed that intracytosolic shigella either become compartmentalized in septin ... | 2010 | 21075354 |
| shigella flexneri spa15 crystal structure verified in solution by double electron electron resonance. | shigella flexneri spa15 is a chaperone of the type 3 secretion system, which binds a number of effectors to ensure their stabilization prior to secretion. one of these effectors is ipgb1, a mimic of the human ras-like rho guanosine triphosphatase rhog. in this study, spa15 alone and in complex with ipgb1 has been studied by double electron electron resonance, an experiment that gives distance information showing the spacial separation of attached spin labels. this distance is explained by determ ... | 2010 | 21075116 |
| anaerobic environment of the intestine primes pathogenic shigella for infection. | marteyn et al. have investigated the role of oxygen and the regulator fnr in infection by the intracellular enteric pathogen shigella flexneri. fnr is active under anaerobic conditions like those present in the lumen of the distal intestine. fnr causes elongation of a secretion apparatus required for bacterial entry into cells and represses secretion of proteins that trigger entry. higher oxygen levels present at the intestinal cell surface are sufficient to inactivate fnr, thereby derepressing ... | 2010 | 21073287 |
| the host outer membrane proteins ompa and ompc are associated with the shigella phage sf6 virion. | assembly of dsdna bacteriophage is a precisely programmed process. potential roles of host cell components in phage assembly haven't been well understood. it was previously reported that two unidentified proteins were present in bacteriophage sf6 virion (casjens et al, 2004, j.mol.biol. 339, 379-394, fig. 2a). using tandem mass spectrometry, we have identified the two proteins as outer membrane proteins (omps) ompa and ompc from its host shigella flexneri. the transmission electron cryo-microsco ... | 2010 | 21071053 |
| prevalence and characterization of human shigella infections in henan province, china, in 2006. | in 2006, 3,531 fecal samples were collected from patients with diarrhea in henan province, china. a total of 467 (13.2%) shigella strains were isolated and serotyped. seventy-one shigella flexneri strains were characterized by mic determination, pulsed-field gel electrophoresis (pfge), and detection of genes encoding cephalosporin resistance. most infections were caused by s. flexneri variant x [iv:(7),8] (27.6%), s. sonnei (24.2%), and s. flexneri 2a (20.8%). however, large regional differences ... | 2010 | 21068291 |
| [antibacterial antibodies in human immunoglobulins and sera: past and present]. | to measure levels of several types of antibacterial antibodies in preparations of normal human immunoglobulin as well as in samples of donor sera obtained in 1965 and 2009. | 2010 | 21061576 |
| research progress in shigella in the postgenomic era. | gram-negative, facultative intracellular anaerobes of the genus shigella, the principal etiologic agents of shigellosis, continue to pose a threat to public health. shigellosis causes 1.1 million deaths with over 164 million annual cases. the shigella spp. can be divided into four serogroups: shigella dysenteriae, shigella flexneri, shigella boydii and shigella sonnei. the completion of seven shigella genome sequences of representative strains from each of the shigella species has introduced an ... | 2010 | 21046319 |
| prevalence of shigellosis diarrhoea in a paediatrics population: hospital based survey in bangui, central african republic. | shigellosis is still a major public health problem in sub-saharan countries, especially among children. | 2010 | 21045359 |
| evidence of cellular immune response to outer membrane protein of salmonella typhimurium in patients with enthesitis-related arthritis subtype of juvenile idiopathic arthritis. | enthesitis-related arthritis subtype of juvenile idiopathic arthritis (jia-era) clinically resembles reactive arthritis (rea). in patients with rea the immune response is targeted at the outer membrane protein (omp) of salmonella typhimurium. we studied the immune response in jia-era to s. typhimurium omp. | 2010 | 21041273 |
| safety, dose, immunogenicity, and transmissibility of an oral live attenuated shigella flexneri 2a vaccine candidate (sc602) among healthy adults and school children in matlab, bangladesh. | in double-blind trials in bangladesh, 88 adults, and 79 children (8-10 years) were randomized to receive either a single oral dose of 1 × 10(4), 1 × 10(5) or 1 × 10(6)cfu of sc602 (a live, attenuated shigella flexneri 2a strain vaccine) or placebo. in the adult outpatient 1 × 10(6) cfu group, severe joint pain and body aches were reported by one and two vaccinees respectively. in the adult inpatient trial, sc602 was isolated from 3 volunteers, pre-vaccination antibody titers were high, and fourf ... | 2010 | 21040694 |
| laboratory based surveillance of travel-related shigella sonnei and shigella flexneri in alberta from 2002 to 2007. | abstract: between 2002 and 2007, travel related cases of shigella sonnei and s. flexneri in alberta, canada were acquired from central america, the indian subcontinent and north america. of this group, resistance to ciprofloxacin and nalidixic acid was identified in isolates from patients who had travelled to the indian subcontinent. this study provides a canadian perspective to a growing body of literature linking ciprofloxacin and nalidixic acid resistance to travel to the indian subcontinent. ... | 2010 | 21040566 |
| counting bacteria on a microfluidic chip. | this paper reports a lab-on-a-chip device that counts the number of bacteria flowing through a microchannel. the bacteria number counting is realized by a microfluidic differential resistive pulse sensor (rps). by using a single microfluidic channel with two detecting arm channels placed at the two ends of the sensing section, the microfluidic differential rps can achieve a high signal-to-noise ratio. this method is applied to detect and count bacteria in aqueous solution. the detected rps signa ... | 2010 | 21035606 |
| genetic characterization of atypical shigella flexneri isolated in korea. | three types of serotypically atypical shigella flexneri strains were isolated from 2007 to 2008 in patients at the korea national institute of health (nih). these strains were characterized and compared with serologically typical s.flexneri. one type of strain either displayed nonreacting typing or grouping sera, reacting strongly only with polyb antisera, which indicates this strain is s. flexneri (polyb:un). the second type displayed reactions with one of the typing sera (iv) and did not bind ... | 2010 | 21030833 |
| effects of backbone substitutions on the conformational behavior of shigella flexneri o-antigens: implications for vaccine strategy. | the o-antigen (o-ag), the polysaccharide part of the lipopolysaccharide, is the major target of the serotype-specific protective humoral response elicited upon host infection by shigella flexneri, the main causal agent of the endemic form of bacillary dysentery. the o-ag repeat units (rus) of 12 s. flexneri serotypes share the tetrasaccharide backbone →2)-α-l-rhap-(1 → 2)-α-l-rhap-(1 → 3)-α-l-rhap-(1 → 3)-β-d-glcpnac-(1→, with site-selective glucosylation(s) and/or o-acetylation defining the ser ... | 2010 | 21030536 |
| antigenic relationship of shigella dispar, types i and ii, to shigella paradysenteriae, boyd type p143. | 1946 | 21024155 | |
| shigellosis studies; resistance of shigella flexneri iii to therapy with sulfadiazine. | 1946 | 21022905 | |
| the phase variation of shigella paradysenteriae (flexner) type iv. | 1946 | 21018824 | |
| shigella paradysenteriae (flexner) type ii. vii. | 1946 | 21018819 | |
| a comparison of rabbit and mouse antisera to shigella paradysenteriae. | 1946 | 21018814 | |
| the antigenic complex of shigella paradysenteriae, boyd type p274. | 1946 | 21018687 | |
| two paracolon cultures related antigenically to shigella paradysenteriae. | 1946 | 21014237 | |
| relationship between precipitative and protective anti-bodies of type iii shigella paradysenteriae (flexner) immune serum. | 1945 | 21004030 | |
| the antigenicity of shigella paradysenteriae (flexner) in saline-in-mineral-oil emulsion. | 1945 | 21004019 | |
| the type-specificity of immune protection against shigella paradysenteriae (flexner). | 1945 | 21003545 | |
| the increase of bacteriophage in vivo during experimental infections with shigella paradysenteriae flexner in mice. | 1946 | 20996528 | |
| two new types of shigella flexneri. | 1946 | 20996438 | |
| the increased antigenicity of shigella paradysenteriae (flexner) in saline-in-mineral-oil emulsion; experiments in mice and rabbits. | 1946 | 20992665 | |
| immunochemical studies on the shigella paradysenteriae (flexner). | 1946 | 20987082 | |
| an additional shigella paradysenteriae serotype. | 1946 | 20985564 | |
| shigellosis studies; clinical observations on dysentery caused by shigella flexneri iii. | 1946 | 20982721 | |
| atypical class 1 integron coexists with class 1 and class 2 integrons in multi-drug resistant shigella flexneri isolates from china. | the antimicrobial resistance and the character of integrons were determined in 58 shigella flexneri strains isolated from china. all isolates were multi-drug resistant and found to carry integrons of class 1 (94.8%), class 2 (100%), or both (94.8%). no inti3 was detected. the typical class 1 integrons were found in conjugative plasmids and could be transferred to the recipient e. coli dh5α. the gene cassettes of typical class 1 integrons dfra17-aada5 and dfra12-orff-aada2 were detected in 54 str ... | 2010 | 20976456 |
| ikkα contributes to canonical nf-κb activation downstream of nod1-mediated peptidoglycan recognition. | during pathogen infection, innate immunity is initiated via the recognition of microbial products by pattern recognition receptors and the subsequent activation of transcription factors that upregulate proinflammatory genes. by controlling the expression of cytokines, chemokines, anti-bacterial peptides and adhesion molecules, the transcription factor nuclear factor-kappa b (nf-κb) has a central function in this process. in a typical model of nf-κb activation, the recognition of pathogen associa ... | 2010 | 20976174 |