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one-step sensitive detection of salmonella typhimurium by coupling magnetic capture and fluorescence identification with functional nanospheres.sensitive, rapid, and reliable detection of bacteria has always been pursued due to the great threat of the bacteria to human health. in this study, a convenient one-step strategy for detecting salmonella typhimurium was developed. immunomagnetic nanospheres (imns) and immunofluorescent nanospheres (ifns) were used to specifically capture and recognize s. typhimurium simultaneously. after magnetic separation, the sandwich immune complexes (imns-bacteria-ifns) were detected under a fluorescence m ...201323256523
comparison of ims platforms for detecting and recovering escherichia coli o157 and shigella flexneri in foods.two automated platforms using immunomagnetic separation technology were compared for detecting and recovering escherichia coli o157 in ground beef and sprouts and shigella flexneri in green onions. the foods were inoculated with <20 cfu/25 g and tested at 5 and 24 h postincubation. immunomagnetic beads were mixed with food enrichments, processed through the pathatrix auto or kingfisher flex, and tested by real-time pcr (qpcr) and recovery on selective agars. at 5 h, the pathatrix auto detected e ...201323190790
shigella flexneri 3a outer membrane protein c epitope is recognized by human umbilical cord sera and associated with protective activity.shigella flexneri 3a is one of the five major strains of the shigella genus responsible for dysentery, especially among children, in regions of high poverty and poor sanitation. the outer membrane proteins (omp) of this bacterium elicit immunological responses and are considered a prime target for vaccine development. when injected into mice they elicit a protective immunological response against a lethal dose of the pathogen. the omps from s. flexneri 3a were isolated and resolved by two-dimens ...201323940590
eata, an immunogenic protective antigen of enterotoxigenic escherichia coli, degrades intestinal mucin.enterotoxigenic escherichia coli (etec) is a major cause of morbidity and mortality due to infectious diarrhea in developing countries for which there is presently no effective vaccine. a central challenge in etec vaccinology has been the identification of conserved surface antigens to formulate a broadly protective vaccine. here, we demonstrate that eata, an immunogenic secreted serine protease of etec, contributes to virulence by degrading muc2, the major protein present in the small intestina ...201324478066
subversion of inflammasome activation and pyroptosis by pathogenic bacteria.activation of the inflammasome occurs in response to a notably high number of pathogenic microbes and is a broad innate immune response that effectively contributes to restriction of pathogen replication and generation of adaptive immunity. activation of these platforms leads to caspase-1- and/or caspase-11-dependent secretion of proteins, including cytokines, and induction of a specific form of cell death called pyroptosis, which directly or indirectly contribute for restriction of pathogen rep ...201324324933
human naip and mouse naip1 recognize bacterial type iii secretion needle protein for inflammasome activation.inflammasome mediated by central nucleotide-binding and oligomerization domain (nod)-like receptor (nlr) protein is critical for defense against bacterial infection. here we show that type iii secretion system (t3ss) needle proteins from several bacterial pathogens, including salmonella typhimurium, enterohemorrhagic escherichia coli, shigella flexneri, and burkholderia spp., can induce robust inflammasome activation in both human monocyte-derived and mouse bone marrow macrophages. needle protei ...201323940371
single cell measurements of vacuolar rupture caused by intracellular pathogens.shigella flexneri are pathogenic bacteria that invade host cells entering into an endocytic vacuole. subsequently, the rupture of this membrane-enclosed compartment allows bacteria to move within the cytosol, proliferate and further invade neighboring cells. mycobacterium tuberculosis is phagocytosed by immune cells, and has recently been shown to rupture phagosomal membrane in macrophages. we developed a robust assay for tracking phagosomal membrane disruption after host cell entry of shigella ...201323792688
characterization of intracellular growth regulator icgr by utilizing transcriptomics to identify mediators of pathogenesis in shigella flexneri.shigella species gram-negative bacteria which cause a diarrheal disease, known as shigellosis, by invading and destroying the colonic mucosa and inducing a robust inflammatory response. with no vaccine available, shigellosis annually kills over 600,000 children in developing countries. this study demonstrates the utility of combining high-throughput bioinformatic methods with in vitro and in vivo assays to provide new insights into pathogenesis. comparisons of in vivo and in vitro gene expressio ...201323753632
deletion of pic results in decreased virulence for a clinical isolate of shigella flexneri 2a from china.shigella is a major pathogen responsible for bacillary dysentery, a severe form of shigellosis. severity of the disease depends on the virulence of the infecting strain. shigella pathogenicity is a multi-gene phenomenon, involving the participation of genes on an unstable large virulence plasmid and chromosomal pathogenicity islands.201323391153
asians and medication. 20133849596
acute bacterial endocarditis in early infancy. 20133679615
synthesis, biological evaluation and molecular docking studies of some pyrimidine derivatives.some novel pyrimidine-5-carbonitrile derivatives bearing various substituent have been synthesized. the structures of target compounds were confirmed by elemental analysis and spectral data. some selected members of the newly synthesized compounds were investigated for their cytotoxic potency against certain human tumor cell lines. five representative active anticancer compounds 6a, 6c, 6d, 17a and 18a were subjected to docking using moe program on the 3d structure of two enzymes, namely; thymid ...201323811090
a creb3-arf4 signalling pathway mediates the response to golgi stress and susceptibility to pathogens.treatment of cells with brefeldin a (bfa) blocks secretory vesicle transport and causes a collapse of the golgi apparatus. to gain more insight into the cellular mechanisms mediating bfa toxicity, we conducted a genome-wide haploid genetic screen that led to the identification of the small g protein adp-ribosylation factor 4 (arf4). arf4 depletion preserves viability, golgi integrity and cargo trafficking in the presence of bfa, and these effects depend on the guanine nucleotide exchange factor ...201324185178
isolation and characterization of antimicrobial constituents of searsia chirindensis l. (anacardiaceae) leaf extracts.searsia chirindensis is used in south african traditional medicine for management of bacterial infections such as diarrhoea. aim of the study was to examine the phytochemical composition from the leaves of searsia chirindensis that is responsible for the ethnomedicinal use of this plant.201324060408
noncanonical inflammasome activation by intracellular lps independent of tlr4.gram-negative bacteria including escherichia coli, citrobacter rodentium, salmonella typhimurium, and shigella flexneri are sensed in an ill-defined manner by an intracellular inflammasome complex that activates caspase-11. we show that macrophages loaded with synthetic lipid a, e. coli lipopolysaccharide (lps), or s. typhimurium lps activate caspase-11 independently of the lps receptor toll-like receptor 4 (tlr4). consistent with lipid a triggering the noncanonical inflammasome, lps containing ...201323887873
safety assessment and probiotic evaluation of enterococcus faecium yf5 isolated from sourdough.enterococcus faecium yf5, a strain previously isolated from sourdough, was assessed for safety and probiotic potential. its virulence and antibiotic resistant phenotypes (cytolysin and gelatinase production, antibiotic susceptibility) and genes (cyla, gele, ace, agg, esp, and vana) were surveyed. results indicated that the tested virulence determinants were nontoxic. in addition, e. faecium yf5 was sensitive to 3 antibiotics such as amoxicillin, vancomycin, and chloramphenicol. furthermore, resu ...201323488799
immobilization of lysozyme-clea onto electrospun chitosan nanofiber for effective antibacterial applications.chitosan (cs) nanofibers with a diameter of 150-200nm were fabricated from a mixed chitosan/poly (vinyl alcohol) (pva) solution by the electrospinning method. the nascent cs/pva nanofibers were treated with 0.5m naoh solution to make stable cs nanofibers by removing pva under aqueous conditions. hen egg-white lysozyme was immobilized on electrospun cs nanofibers via cross-linked enzyme aggregates (cleas) and used for effective and continuous antibacterial applications. the maximum amount of lyso ...201323201775
molecular structure, normal coordinate analysis, harmonic vibrational frequencies, natural bond orbital, td-dft calculations and biological activity analysis of antioxidant drug 7-hydroxycoumarin.in this work, we report harmonic vibrational frequencies, molecular structure, nbo and homo, lumo analysis of umbelliferone also known as 7-hydroxycoumarin (7hc). the optimized geometric bond lengths and bond angles obtained by computation (monomer and dimmer) shows good agreement with experimental xrd data. harmonic frequencies of 7hc were determined and analyzed by dft utilizing 6-311+g(d,p) as basis set. the assignments of the vibrational spectra have been carried out with the help of normal ...201323123244
synthesis, spectroscopic, molecular orbital calculation, cytotoxic, molecular docking of dna binding and dna cleavage studies of transition metal complexes with n-benzylidene-n'-salicylidene-1,1-diaminopropane.eight mononuclear chromium(iii), manganese(ii), iron(iii), cobalt(ii), nickel(ii), copper(ii), zinc(ii) and cadmium(ii) complexes of schiff's base ligand were synthesized and determined by different physical techniques. the complexes are insoluble in common organic solvents but soluble in dmf and dmso. the measured molar conductance values in dmso indicate that the complexes are non-electrolytic in nature. all the eight metal complexes have been fully characterized with the help of elemental ana ...201323831943
expression of shigella flexneri ipab gene in tobacco.shigellosis is a leading cause of diarrhea in many developing countries and although the disease can be controlled and managed with antibiotics, the constant emergence of resistant species requiring ever newer antibacterial drugs make development of an effective vaccine necessary. the bacteria are highly contagious and since immunity to shigella is serotype-specific a multi-serotype vaccine is required for adequate protection. proteins encoded by shigella invasion plasmid, which are part of the ...201323799180
bacteremia in patients with acute pancreatitis as revealed by 16s ribosomal rna gene-based techniques*.to define the characteristic of bacteremia in patients with acute pancreatitis and determine its possible association with the disease severity.201323863226
bacteremia in the patients with acute pancreatitis as revealed by 16s ribosomal rna gene-based techniques.objectives:: to define the characteristic of bacteremia in the patients with acute pancreatitis and determine its possible association with the disease severity. design:: a prospective controlled study. setting:: icu of jinling hospital, china. patients:: a total of 48 patients with mild or severe acute pancreatitis were enrolled in this study. interventions:: none. measurements and main results:: samples of peripheral blood were collected from the patients at 4 or 5 and 9 or 10 days after acute ...201323764972
an alternative outer membrane secretion mechanism for an autotransporter protein lacking a c-terminal stable core.autotransporter (at) proteins are a broad class of virulence factors from gram-negative pathogens. at outer membrane (om) secretion appears simple in many regards, yet the mechanism that enables transport of the central at 'passenger' across the om remains unclear. om secretion efficiency for two at passengers is enhanced by approximately 20 kda stable core at the c-terminus of the passenger, but studies on a broader range of at proteins are needed in order to determine whether a stability diffe ...201324118465
synthesis and concentration dependent antibacterial activities of cuo nanoflakes.we report, synthesis and antibacterial activities of cuo nanoflakes. cuo nanoparticles are prepared at room temperature through sol-gel method. x-ray diffraction studies show the particles are monoclinic (crystalline) in nature. scanning electron microscopy (sem) images clearly show that the prepared particles are flake like in structure. fourier transform infrared (ftir) spectra exhibits three different bands that correspond to the au and bu modes. antibacterial studies were performed on shigel ...201323498227
multiplex pcr (polymerase chain reaction) assay for detection of e. coli o157:h7, salmonella sp., vibrio cholerae and vibrio parahaemolyticus in spiked shrimps (penaeus monodon).the coastal aquaculture mainly shrimps constitute major export sector in bangladesh and is increasingly shaped by international trade conditions and by national responses to those stringent quality and safety standards. pcr based validated methods for detection of major bacterial pathogens in shrimp might be very useful tool for ensuring quality and safety standards of exportable shrimps. the objective of this study was to evaluate overall performance (sensitivity and specificity) of the multipl ...201324498789
combination of extracts from aristolochia cymbifera with streptomycin as a potential antibacterial drug.the appearance of new antibiotic-resistant bacteria is a societal problem that requires the development of new alternative treatments. therefore, this work evaluated the antibacterial activity of ethanolic (ehi), dichloromethanic (edi) and hexanic (ehe) extracts from aristolochia cymbifera stems and the combination of these extracts with an antimicrobial drug to develop a new antibacterial therapy. the edi, ehe and ehi extracts were obtained by maceration using three different solvents. the mini ...201324040585
screening of solvent dependent antibacterial activity of prunus domestica.fruit of prunus domestica was extracted in ethanol. the ethanol extract was further extracted with two solvents ethyl acetate and chloroform. the crude ethanol extract and two fractions (ethyl acetate and chloroform) were screened for their antibacterial activity using the agar well diffusion method .they were tested against nine bacteria; five gram positive bacteria (staphylococcus aureus, streptococcuc intermedius, bacillus cereus, bacillus pumilus) and four gram negative bacteria (eschrichia ...201323455215
antimicrobial and antioxidant activities of alcoholic extracts of rumex dentatus l.in-vitro antimicrobial and antioxidant activities of various concentrations ranging from 150 to 500 μg/ml of alcoholic (methanol and ethanol) extracts of rumex dentatus were analyzed on different clinical bacterial strains (shigella flexneri, klebsiella pneumoniae, escherichia coli, pseudomonas aeruginosa, salmonella typhimurium, staphylococcus aureus) and fungal strains (aspergillus versicolor, aspergillus flavus, acremonium spp., penicillium dimorphosporum, candida albicans, candida kruesie, c ...201323415966
spontaneous mutation frequency and molecular mechanisms of shigella flexneri fluoroquinolone resistance under antibiotic selective stress.the incidence of fluoroquinolone-resistant shigella strains has risen rapidly, presumably in response to ciprofloxacin antibiotic stress. understanding the molecular mechanisms underlying this resistance phenotype is critical to developing novel and effective therapeutic strategies. in this study, the frequency of ciprofloxacin-induced mutation was measured in antibiotic resistance genes (gyra, gyrb, parc, pare, maror, and mara) of shigella flexneri. the s. flexneri 2a strain 301 was cultured on ...201323070800
towards a non-living vaccine against shigella flexneri: from the inactivation procedure to protection studies.shigellosis is one of the leading causes of diarrhea worldwide with more than 165 million cases annually. hence, a vaccine against this disease is a priority, but no licensed vaccine is still available. considering target population as well as intrinsic risks of live attenuated vaccines, non-living strategies appear as the most promising candidates. remarkably, the preservation of antigenic properties is a major concern since inactivation methods of bacteria affect these qualities. we previously ...201323046911
myosin-x facilitates shigella-induced membrane protrusions and cell-to-cell spread.the intracellular pathogen shigella flexneri forms membrane protrusions to spread from cell to cell. as protrusions form, myosin-x (myo10) localizes to shigella. electron micrographs of immunogold-labelled shigella-infected hela cells reveal that myo10 concentrates at the bases and along the sides of bacteria within membrane protrusions. time-lapse video microscopy shows that a full-length myo10 gfp-construct cycles along the sides of shigella within the membrane protrusions as these structures ...201323083060
o-antigen structure of shigella flexneri serotype yv and effect of the lpt-o gene variation on phosphoethanolamine modification of s. flexneri o-antigens.shigella flexneri is the major human pathogen causing shigellosis. o-antigens of all s. flexneri serotypes (except for serotype 6) share the →2)-α-l-rhap(iii)-(1 → 2)-α-l-rhap(ii)-(1 → 3)-α-l-rhap(i)-(1 → 3)-β-d-glcpnac-(1→ basic o-unit, whereas differences between the serotypes are conferred by phage-encoded glucosylation and/or o-acetylation at various positions. recently, in serotype x and 4a variants called xv and 4av, respectively, o-antigen modification with phosphoethanolamine (petn) has ...201323283000
human plasma-derived polymeric iga and igm antibodies associate with secretory component to yield biologically active secretory-like antibodies.immunotherapy with monoclonal and polyclonal immunoglobulin is successfully applied to improve many clinical conditions, including infection, autoimmune diseases, or immunodeficiency. most immunoglobulin products, recombinant or plasma-derived, are based on igg antibodies, whereas to date, the use of iga for therapeutic application has remained anecdotal. in particular, purification or production of large quantities of secretory iga (siga) for potential mucosal application has not been achieved. ...201323250751
bruton's tyrosine kinase regulates shigella flexneri dissemination in ht-29 intestinal cells.shigella flexneri is a gram-negative intracellular pathogen that infects the intestinal epithelium and utilizes actin-based motility to spread from cell to cell. s. flexneri actin-based motility has been characterized in various cell lines, but studies in intestinal cells are limited. here we characterized s. flexneri actin-based motility in ht-29 intestinal cells. in agreement with studies conducted in various cell lines, we showed that s. flexneri relies on neural wiskott-aldrich syndrome prot ...201323230296
identification of shigella flexneri icsa residues affecting interaction with n-wasp, and evidence for icsa-icsa co-operative interaction.the shigella flexneri icsa (virg) protein is a polarly distributed outer membrane protein that is a fundamental virulence factor which interacts with neural wiskott-aldrich syndrome protein (n-wasp). the activated n-wasp then activates the arp2/3 complex which initiates de novo actin nucleation and polymerisation to form f-actin comet tails and allows bacterial cell-to-cell spreading. in a previous study, icsa was found to have three n-wasp interacting regions (irs): ir i (aa 185-312), ir ii (aa ...201323405119
residues located inside the escherichia coli fepe protein oligomer are essential for lipopolysaccharide o-antigen modal chain length regulation.the escherichia coli o157 : h7 fepe protein regulates lipopolysaccharide (lps) o-antigen (oag) chain length to confer a very long modal chain length of >80 oag repeat units (rus). the mechanism by which fepe regulates oag modal chain length and the regions within it that are important for its function remain unclear. studies on the structure of fepe show that the protein oligomerizes. however, the exact size of the oligomer is in dispute, further hampering our understanding of its mechanism. gui ...201323393150
complete genome sequence of sfii, a serotype-converting bacteriophage of the highly prevalent shigella flexneri serotype 2a.sfii is a serotype-converting temperate bacteriophage of the highly prevalent shigella flexneri serotype 2a. we isolated the sfii phage from a wild-type strain of s. flexneri serotype 2a. here, we present the complete genome sequence of this phage.201324029753
phyllanthus wightianus müll. arg.: a potential source for natural antimicrobial agents.phyllanthus wightianus belongs to euphorbiaceae family having ethnobotanical importance. the present study deals with validating the antimicrobial potential of solvent leaf extracts of p. wightianus. 11 human bacterial pathogens (bacillus subtilis, streptococcus pneumoniae, staphylococcus epidermidis, proteus vulgaris, pseudomonas aeruginosa, klebsiella pneumoniae, salmonella typhimurium, escherichia coli, shigella flexneri, proteus vulgaris, and serratia marcescens) and 4 fungal pathogens (cand ...201424883301
metal-based carboxamide-derived compounds endowed with antibacterial and antifungal activity.a series of three bioactive thiourea (carboxamide) derivatives, n-(dipropylcarbamothioyl)-thiophene-2-carboxamide (l(1)), n-(dipropylcarbamothioyl)-5-methylthiophene-2-carboxamide (l(2)) and 5-bromo-n-(dipropylcarbamothioyl)furan-2-carboxamide (l(3)) and their cobalt(ii), copper(ii), nickel(ii) and zinc(ii) complexes (1)-(12) have been synthesized and characterized by their ir,(1)h-nmr spectroscopy, mass spectrometry and elemental analysis data. the crystal structure of one of the ligand, n-(dip ...201423914928
impact of reclaimed water irrigation on antibiotic resistance in public parks, beijing, china.the abundance and distribution of antibiotics and antibiotic resistance genes (args) in soils from six parks using reclaimed water in beijing, china, were characterized. three classes of commonly used antibiotics (tetracycles, quinolones, and sulfonamides) were analyzed by liquid chromatography-tandem mass spectrometry (lc-ms/ms). the highest concentrations of tetracyclines and quinolones were 145.2 μg kg(-1) and 79.2 μg kg(-1), respectively. detected tetg, tetw, suli, and sulii genes were quant ...201424071635
¹³c, ¹⁵n and ¹h backbone and side chain chemical shift assignment of acid-stress bacterial chaperone hdea at ph 6.hdea is a small chaperone found in the periplasm of several common pathogenic bacteria (escherichia coli, shigella flexneri and brucella abortus) which are the leading causes of dysentery worldwide, especially in developing countries. its job is to protect other periplasmic proteins from aggregating as the bacteria pass through the low ph environment of the human stomach on their way to infect the intestines. hdea is an inactive folded dimer at neutral ph, but becomes a disordered active monomer ...201423835624
detection of salmonella spp. by a loop-mediated isothermal amplification (lamp) method targeting bcfd gene.in this study, we developed and validated a loop-mediated isothermal amplification (lamp) assay for salmonella detection targeting bcfd gene, a conserved fimbrial operon gene existing in salmonella. the salmonella lamp assay we developed successfully amplified 44 salmonella strains (14 standard strains and 30 clinical isolates), but none of 9 non-salmonella standard strains (proteus mirabilis, listeria monocytogenes, escherichia coli, pseudomonas aeruginosa, shigella flexneri, shigella sonnei, k ...201425199410
decay of genetic markers for fecal bacterial indicators and pathogens in sand from lake superior.beach sands impact water quality and pathogen loads, however, the comparative decay of the fecal indicator bacteria (fib) enterococcus spp. and escherichia coli, and pathogens in freshwater sand have not been examined. in this study, freshwater sand microcosms were inoculated with sewage and pure cultures of bacterial pathogens to compare relative decay rates. the abundance of culturable enterococcus spp. and e. coli, genetic markers for enterococcus spp. (entero1), total bacteroides (allbac), a ...201424793108
biosynthesis of silver nanoparticles using acacia leucophloea extract and their antibacterial activity.the immense potential of nanobiotechnology makes it an intensely researched field in modern medicine. green nanomaterial synthesis techniques for medicinal applications are desired because of their biocompatibility and lack of toxic byproducts. we report the toxic byproducts free phytosynthesis of stable silver nanoparticles (agnps) using the bark extract of the traditional medicinal plant acacia leucophloea (fabaceae). visual observation, ultraviolet-visible spectroscopy, and transmission elect ...201424876776
cgtase-catalysed cis-glucosylation of l-rhamnosides for the preparation of shigella flexneri 2a and 3a haptens.we report the enzymatic synthesis of α-d-glucopyranosyl-(1→4)-α-l-rhamnopyranoside and α-d-glucopyranosyl-(1→3)-α-l-rhamnopyranoside by using a wild-type transglucosidase in combination with glucoamylase and glucose oxidase. it was shown that bacillus circulans 251 cyclodextrin glucanotransferase (cgtase, ec 2.1.4.19) can efficiently couple an α-l-rhamnosyl acceptor to a maltodextrin molecule with an α-(1→4) linkage, albeit in mixture with the α-(1→3) regioisomer, thus giving two glucosylated ac ...201424376024
stress tolerant virulent strains of cronobacter sakazakii from food.cronobacter sakazakii is considered as an emerging foodborne pathogen. the aim of this study was to isolate and characterize virulent strains of cronobacter sakazakii from food samples of bangladesh.201425723712
synthesis, structural characterization, and evaluation of the biological properties of heteroleptic palladium(ii) complexes.five heteroleptic palladium(ii) complexes of the general formula pd(pr3)(tu)cl2, where pr3 = triphenylphosphine (1), diphenyl-o-tolylphosphine (2), diphenyl-p-tolylphosphine (3), diphenyl-t-butylphosphine (4), and diphenyl-o-methoxyphenylphosphine (5), and tu = 1,3-bis(2-methoxyphenyl) thiourea. they all have been synthesized and characterized by various spectroscopic techniques (elemental analysis, ftir, and (1)h nmr and the ligand 1,3-bis(2-methoxyphenyl) thiourea was synthesized by single cry ...201425276113
profile of volatile components of hydrodistilled and extracted leaves of jacaranda acutifolia and their antimicrobial activity against foodborne pathogens.volatile constituents of the essential oil and n-hexane extract of jacaranda acutifolia humb. and bonpl. (bignoniaceae) leaves were determined, and their antimicrobial activities were investigated using an agar diffusion method. the minimum inhibitory concentrations (mic) were determined and compared with those of standard antibiotics (penicillin, gentamicin and nystatin). the chemical composition of the oils was analyzed by capillary gas chromatography (glc-fid) and gas chromatography-mass spec ...201425230515
cold-active antibacterial and antifungal activities and antibiotic resistance of bacteria isolated from an alpine hydrocarbon-contaminated industrial site.selection pressure in hydrocarbon-contaminated soils may lead not only to increased microbial resistance to antibiotics, but also to increased capacity of the soil indigenous population to produce antimicrobial compounds. therefore, we studied the antibiotic resistance pattern and antibacterial and/or antifungal activities of 47 bacterial strains isolated from an industrial alpine site heavily polluted with petroleum hydrocarbons. resistance to penicillin was more widespread (49%) than resistanc ...201424880083
synthesis, structures, spectroscopy and antimicrobial properties of complexes of copper(ii) with salicylaldehyde n-substituted thiosemicarbazones and 2,2'-bipyridine or 1,10-phenanthroline.among the biometals (cu, co, ni-cofactors in many enzymes), copper derivatives of o, n, s-donor salicylaldehyde thiosemicarbazones have received considerable attention owing to their potential biological applications. eight new complexes of salicylaldehyde-n-substituted thiosemicarbazones [5-meo-2-ho-c₆h₄-c(2)(h)n(3)-n(2)h-c(1)(s)-n(1)hr; r = me, h2l(1); et, h₂l(1), ph, h₂l(3), h, h₂l(4)] with copper(ii), namely, [cu(κ(3)-o,n,s-l)( κ(2)-n,n-l')] {(l)(2-) = (l(1))(2-), l' = bipy, 1, phen, 2; (l)( ...201424583354
[an occupational disease to be recognized as compensable: dermatitis caused by japan]. 20144265329
[bellyache or acute abdomen?]. 20143960141
nifedipine-induced psychosis. 20143968373
speech and psychopathology. 20143897749
development of an aotus nancymaae model for shigella vaccine immunogenicity and efficacy studies.several animal models exist to evaluate the immunogenicity and protective efficacy of candidate shigella vaccines. the two most widely used nonprimate models for vaccine development include a murine pulmonary challenge model and a guinea pig keratoconjunctivitis model. nonhuman primate models exhibit clinical features and gross and microscopic colonic lesions that mimic those induced in human shigellosis. challenge models for enterotoxigenic escherichia coli (etec) and campylobacter spp. have be ...201424595138
the periplasmic enzyme, ansb, of shigella flexneri modulates bacterial adherence to host epithelial cells.s. flexneri strains, most frequently linked with endemic outbreaks of shigellosis, invade the colonic and rectal epithelium of their host and cause severe tissue damage. here we have attempted to elucidate the contribution of the periplasmic enzyme, l-asparaginase (ansb) to the pathogenesis of s. flexneri. using a reverse genetic approach we found that ansb mutants showed reduced adherence to epithelial cells in vitro and attenuation in two in vivo models of shigellosis, the caenorhabditis elega ...201424762742
systematic analysis of bacterial effector-postsynaptic density 95/disc large/zonula occludens-1 (pdz) domain interactions demonstrates shigella ospe protein promotes protein kinase c activation via pdlim proteins.diseases caused by many gram-negative bacterial pathogens depend on the activities of bacterial effector proteins that are delivered into eukaryotic cells via specialized secretion systems. effector protein function largely depends on specific subcellular targeting and specific interactions with cellular ligands. pdz domains are common domains that serve to provide specificity in protein-protein interactions in eukaryotic systems. we show that putative pdz-binding motifs are significantly enrich ...201425124035
rna-seq analysis of the influence of anaerobiosis and fnr on shigella flexneri.shigella flexneri is an important human pathogen that has to adapt to the anaerobic environment in the gastrointestinal tract to cause dysentery. to define the influence of anaerobiosis on the virulence of shigella, we performed deep rna sequencing to identify transcriptomic differences that are induced by anaerobiosis and modulated by the anaerobic fumarate and nitrate reduction regulator, fnr.201424907032
mutational analysis of the shigella flexneri o-antigen polymerase wzy: identification of wzz-dependent wzy mutants.the o-antigen (oag) component of lipopolysaccharide (lps) is a major virulence determinant of shigella flexneri and is synthesized by the o-antigen polymerase, wzysf. oag chain length is regulated by chromosomally encoded wzzsf and phs-2 plasmid-encoded wzzphs2. to identify functionally important amino acid residues in wzysf, random mutagenesis was performed on the wzysf gene in a pwaldo-tev-gfp plasmid, followed by screening with colicin e2. analysis of the lps conferred by mutated wzysf protei ...201425313393
ntrbc and nac contribute to efficient shigella flexneri intracellular replication.shigella flexneri two-component regulatory systems (tcrs) are responsible for sensing changes in environmental conditions and regulating gene expression accordingly. we examined 12 tcrs that were previously uncharacterized for potential roles in s. flexneri growth within the eukaryotic intracellular environment. we demonstrate that the tcrs evgsa, ntrbc, and rstba systems are required for wild-type plaque formation in cultured epithelial cells. the phenotype of the ntrbc mutant depended in part ...201424794563
shigella flexneri targets the hp1γ subcode through the phosphothreonine lyase ospf.hp1 proteins are transcriptional regulators that, like histones, are targets for post-translational modifications defining an hp1-mediated subcode. hp1γ has multiple phosphorylation sites, including serine 83 (s83) that marks it to sites of active transcription. in a guinea pig model for shigella enterocolitis, we observed that the defective type iii secretion mxid shigella flexneri strain caused more hp1γ phosphorylation in the colon than the wild-type strain. shigella interferes with hp1 phosp ...201425216677
polar localization of phon2, a periplasmic virulence-associated factor of shigella flexneri, is required for proper icsa exposition at the old bacterial pole.proper protein localization is critical for bacterial virulence. phon2 is a virulence-associated atp-diphosphohydrolase (apyrase) involved in icsa-mediated actin-based motility of s. flexneri. herein, by analyzing a δphon2 mutant of the s. flexneri strain m90t and by generating phon2::ha fusions, we show that phon2, is a periplasmic protein that strictly localizes at the bacterial poles, with a strong preference for the old pole, the pole where icsa is exposed, and that it is required for proper ...201424587292
serotype-converting bacteriophage sfii encodes an acyltransferase protein that mediates 6-o-acetylation of glcnac in shigella flexneri o-antigens, conferring on the host a novel o-antigen epitope.shigella flexneri o-antigen is an important and highly variable cell component presented on the outer leaflet of the outer membrane. most shigella flexneri bacteria share an o-antigen backbone composed of →2)-α-l-rhap(iii)-(1→2)-α-l-rhap(ii)-(1→3)-α-l-rhap(i)-(1→3)-β-d-glcpnac-(1→ repeats, which can be modified by adding various chemical groups to different sugars, giving rise to diverse o-antigen structures and, correspondingly, to various serotypes. the known modifications include glucosylatio ...201425112477
aerobic bacterial community of american cockroach periplaneta americana,a step toward finding suitable paratransgenesis candidates.cockroaches mechanically spread pathogenic agents, however, little is known about their gut microbiota. identification of midgut microbial community helps targeting novel biological control strategies such as paratransgenesis. here the bacterial microbiota of periplaneta americana midgut, were identified and evaluated for finding proper paratransgenesis candidate.201426114142
widespread antibiotic resistance of diarrheagenic escherichia coli and shigella species.antibiotic resistance of enteric pathogens particularly shigella species, is a critical world-wide problem and monitoring their resistant pattern is essential, because the choice of antibiotics is absolutely dependent on regional antibiotic susceptibility patterns. during summer 2013, an unusual increase in number of diarrheal diseases was noticed in isfahan, a central province of iran. therefore, the antibiotic resistance of diarrheagenic escherichia coli and shigella species isolated were eval ...201425002896
modulation of endotoxicity of shigella generalized modules for membrane antigens (gmma) by genetic lipid a modifications: relative activation of tlr4 and tlr2 pathways in different mutants.outer membrane particles from gram-negative bacteria are attractive vaccine candidates as they present surface antigens in their natural context. we previously developed a high yield production process for genetically derived particles, called generalized modules for membrane antigens (gmma), from shigella. as gmma are derived from the outer membrane, they contain immunostimulatory components, especially lipopolysaccharide (lps). we examined ways of reducing their reactogenicity by modifying lip ...201425023285
analysis on the interaction domain of virg and apyrase by pull-down assay.virg is outer membrane protein of shigella and affects the spread of shigella. recently it has been reported that apyrase influences the location of virg, although the underlying mechanism remains poorly understood. the site of interaction between apyrase and virg is the focus of our research. first we constructed recombinant plasmid phis-phon2 and ps-(v1-1102, v53-758, v759-1102, v53-319, v320-507, v507-758) by denaturation-renaturation, the phon2:kan mutant of shigella flexneri 5a m90t by a mo ...201425379645
a shigella flexneri virulence plasmid encoded factor controls production of outer membrane vesicles.shigella spp. use a repertoire of virulence plasmid-encoded factors to cause shigellosis. these include components of a type iii secretion apparatus (t3sa) that is required for invasion of epithelial cells and many genes of unknown function. we constructed an array of 99 deletion mutants comprising all genes encoded by the virulence plasmid (excluding those known to be required for plasmid maintenance) of shigella flexneri. we screened these mutants for their ability to bind the dye congo red: a ...201425378474
clinical isolates of shiga toxin 1a-producing shigella flexneri with an epidemiological link to recent travel to hispañiola.shiga toxins (stx) are cytotoxins involved in severe human intestinal disease. these toxins are commonly found in shigella dysenteriae serotype 1 and shiga-toxin-producing escherichia coli; however, the toxin genes have been found in other shigella species. we identified 26 shigella flexneri serotype 2 strains isolated by public health laboratories in the united states during 2001-2013, which encode the shiga toxin 1a gene (stx1a). these strains produced and released stx1a as measured by cytotox ...201425271406
evaluation of the ability of four esbl-screening media to detect esbl-producing salmonella and shigella.the aim of this study was to compare the ability of four commercially available media for screening extended-spectrum beta-lactamase (esbl) to detect and identify esbl-producing salmonella and shigella in fecal samples. a total of 71 salmonella- and 21 shigella-isolates producing esbl(a) and/or ampc, were received at norwegian institute of public health between 2005 and 2012. the 92 isolates were mixed with fecal specimens and tested on four esbl screening media; chromid esbl (biomèrieux), brill ...201425204319
proteomes of pathogenic escherichia coli/shigella group surveyed in their host environments.proteomic studies on shigella dysenteriae, shigella flexneri, enterohemorrhagic escherichia coli and uropathogenic e. coli (upec) are reviewed. upec causes infections in the urogenital tract, whereas the other species colonize and, to varying degrees, invade the intestinal tract. type iii secretion systems used to breach the mucosal barrier by the intestinal pathogens revealed distinct expression patterns in different host environments. dynamic adaptations to changes in nutrient availability and ...201425163594
the immune response of two microbial antigens delivered intradermally, sublingually, or the combination thereof.a key consideration to produce a successful vaccine is the choice of appropriate vaccination route. though most vaccines are administered parenterally, this route is not effective in producing a robust mucosal or cell-mediated response. intradermal and sublingual vaccinations have been explored recently as potential needle-free immunization strategies. we explored intradermal and sublingual routes as well as the combination of the two routes in eliciting both systemic and mucosal immune response ...201425111827
[preparation and identification of the polyclonal antibody against gapdh protein from shigella flexneri m90t].to prepare mouse polyclonal antibodies against shigella flexneri m90t glyceraldehyde-3-phosphate dehydrogenase (gapdh), and verify its titer and specificity.201424721410
probiotic potential of lactobacillus plantarum ld1 isolated from batter of dosa, a south indian fermented food.lactobacillus plantarum ld1 was isolated from dosa batter and identified by biochemical, physiological and genetic methods. species level identification was done by 16s rdna amplification and sequencing. the probiotic potential of strain ld1 was assessed by different standard parameters. cell surface hydrophobicity was recorded to be 62% with sat value <0.007 m. seventy-eight percent of viable count was found after treatment with simulated gastric juice containing pepsin (ph 2.0). bile salt tole ...201424676724
rabbit monoclonal antibodies directed at the t3ss effector protein yopm identify human pathogenic yersinia isolates.the yersinia outer protein m (yopm) is a type 3 secretion system (t3ss)-dependent effector protein of yersinia enterocolitica, yersinia pseudotuberculosis and yersinia pestis. although yopm is indispensable for full virulence, its molecular functions still remain largely elusive. recently, we could identify the recombinant yopm (ryopm) protein derived from the y. enterocolitica strain 8081 (jb580) as a cell-penetrating protein, which down-regulates the expression of various pro-inflammatory cyto ...201424636859
intradermal delivery of shigella ipab and ipad type iii secretion proteins: kinetics of cell recruitment and antigen uptake, mucosal and systemic immunity, and protection across serotypes.shigella is one of the leading pathogens contributing to the vast pediatric diarrheal disease burden in low-income countries. no licensed vaccine is available, and the existing candidates are only partially effective and serotype specific. shigella type iii secretion system proteins ipab and ipad, which are conserved across shigella spp., are candidates for a broadly protective, subunit-based vaccine. in this study, we investigated the immunogenicity and protective efficacy of ipab and ipad admi ...201424453241
relationship between o-antigen chain length and resistance to colicin e2 in shigella flexneri.the shigella flexneri polysaccharide co-polymerase class 1a (pcp1a) protein, wzzbsf, regulates lps o-antigen (oag) chain length to confer short (s)-type oag chains of ~10-17 oag repeat units (rus). the s-type oag chains affect shigella flexneri virulence as they influence icsa-mediated actin-based motility. however, they do not confer resistance to complement; this is conferred by the very-long (vl)-type oag chains determined by wzzb(phs2). colicins are bacterial proteins produced by some escher ...201424425769
plantaricin ld1: a bacteriocin produced by food isolate of lactobacillus plantarum ld1.plantaricin ld1, a bacteriocin produced by lactobacillus plantarum ld1, was characterized for biochemical and antimicrobial properties. bacteriocin showed stability at high temperatures (100 °c for 20 min and 121 °c for 15 min under 15 psi pressure), in a ph range of 2.0-8.0 and also in the presence of organic solvents, surfactants and detergents. the crude preparation was not affected by catalase, amylase and lipase but activity was reduced in the presence of pepsin, trypsin and proteinase k sh ...201424522411
probiotic assessment of enterococcus durans 6hl and lactococcus lactis 2hl isolated from vaginal microflora.forty-five lactic acid bacteria (lab) were isolated from the vaginal specimens of healthy fertile women, and the identities of the bacteria were confirmed by sequencing of their 16s rdna genes. among these bacteria, only four isolates were able to resist and survive in low ph, bile salts and simulated in vitro digestion conditions. lactococcus lactis 2hl, enterococcus durans 6hl, lactobacillus acidophilus 36yl and lactobacillus plantarum 5bl showed the best resistance to these conditions. these ...201424913559
quantification of polyphenols and evaluation of antimicrobial, analgesic and anti-inflammatory activities of aqueous and acetone-water extracts of libidibia ferrea, parapiptadenia rigida and psidium guajava.vast numbers of plant species from northeastern brazil have not yet been phytochemically or biologically evaluated.201425124277
age-dependent association among helicobacter pylori infection, serum pepsinogen levels and immune response of children to live oral cholera vaccine cvd 103-hgr.through its effects on gastric secretion, we hypothesized that helicobacter pylori infection may influence oral immunization. accordingly, we examined the association between h. pylori infection, serum pepsinogen (pg) (measures for h. pylori gastritis) and vibriocidal antibody (a correlate of protection) seroconversion following oral immunization with cvd 103-hgr live cholera vaccine among children of different ages.201424454714
hpv16l1-attenuated shigella recombinant vaccine induced strong vaginal and systemic immune responses in guinea pig model.though human papillomavirus (hpv) vaccines based on l1 virus-like particles (vlps) have excellent protective effect against hpv-induced cervical cancer, they are too expensive to be afforded by the developing countries, where most cases of cervical cancer occur. a live bacterial-based vaccine could be an inexpensive alternative. the aim of this study was to evaluate the potential value of live attenuated shigella. flexneri 2a sc602 strain-based hpv16l1 as a high-efficiency, low-cost hpv16l1 muco ...201425483698
electron tomography and simulation of baculovirus actin comet tails support a tethered filament model of pathogen propulsion.several pathogens induce propulsive actin comet tails in cells they invade to disseminate their infection. they achieve this by recruiting factors for actin nucleation, the arp2/3 complex, and polymerization regulators from the host cytoplasm. owing to limited information on the structural organization of actin comets and in particular the spatial arrangement of filaments engaged in propulsion, the underlying mechanism of pathogen movement is currently speculative and controversial. using electr ...201424453943
enhanced antibacterial and anti-biofilm activities of silver nanoparticles against gram-negative and gram-positive bacteria.silver nanoparticles (agnps) have been used as antibacterial, antifungal, antiviral, anti-inflammtory, and antiangiogenic due to its unique properties such as physical, chemical, and biological properties. the present study was aimed to investigate antibacterial and anti-biofilm activities of silver nanoparticles alone and in combination with conventional antibiotics against various human pathogenic bacteria. here, we show that a simple, reliable, cost effective and green method for the synthesi ...201425136281
murine solid tumours as a novel model to study bacterial biofilm formation in vivo.bacteria of many species are able to invade and colonize solid tumours in mice. we have focused on salmonella enterica serovar typhimurium. detailed analysis revealed that such tumour-invading salmonella form biofilms, thus providing a versatile in vivo test system for studying bacterial phenotypes and host-pathogen interactions. it appears that biofilm formation by s. typhimurium is induced as a defence against the immune system of the host, and in particular against neutrophils. further, we ex ...201424724621
convergent evolution in the assembly of polyubiquitin degradation signals by the shigella flexneri ipah9.8 ligase.the human pathogen shigella flexneri subverts host function and defenses by deploying a cohort of effector proteins via a type iii secretion system. the ipah family of 10 such effectors mimics ubiquitin ligases but bears no sequence or structural homology to their eukaryotic counterpoints. using rates of (125)i-polyubiquitin chain formation as a functional read out, ipah9.8 displays v-type positive cooperativity with respect to varying concentrations of its ubc5b∼(125)i-ubiquitin thioester co-su ...201425342744
a gene knock-in method used to purify plasmid pspi12 from salmonella enterica serovar pullorum and characterization of ipaj.a small plasmid with 4080 bp long, designated pspi12, was purified from salmonella enterica serovar pullorum using a gene knock-in method by inserting a kanamycin resistance cassette in the plasmid. the g+c content of the plasmid was 51.8%, which is in the range of salmonella genomic dna. a sequence analysis revealed that pspi12 had 99.1% homology to psfd10, which was first reported in the vaccine strain s. enterica serovar chloreaesuis c500, but not prevalent among other strains of s. chloreaes ...201424468333
isolation and molecular characterization of salmonella enterica, escherichia coli o157:h7 and shigella spp. from meat and dairy products in egypt.foodborne pathogens are a major threat to food safety, especially in developing countries where hygiene and sanitation facilities are often poor. salmonella enterica, escherichia coli o157:h7 and shigella spp. are among the major causes of outbreaks of foodborne diseases. this large-scale study investigated the prevalence of these foodborne pathogens in meat (beef and chicken) and dairy products collected from street vendors, butchers, retail markets and slaughterhouses in egypt. a total of 1600 ...201424239976
molecular characterization of serologically atypical provisional serovars of shigella isolates from kolkata, india.during 2000-2004, 13 shigella strains that were untypable by commercially available antisera were isolated from children <5 years of age with acute diarrhoea in kolkata. these strains were subsequently identified as shigella dysenteriae provisional serovar 204/96 (n = 3), shigella dysenteriae provisional serovar e23507 (n = 1), shigella dysenteriae provisional serovar i9809-73 (n = 1), shigella dysenteriae provisional serovar 93-119 (n = 1), shigella flexneri provisional serovar 88-893 (n = 6) a ...201425261061
shigella: a highly virulent and elusive pathogen.despite a significant decrease in shigella-related mortality, shigellosis continues to carry a significant burden of disease worldwide, particularly in asia and africa. shigella is a highly virulent pathogen comprised of four major species with numerous subtypes. shigella dysenteriae and shigella flexneri infections are predominant in resource-limited settings. clinical presentations range from mild watery diarrhea to severe dysentery with systemic complications such as electrolyte imbalance, se ...201425110633
[stability of changed properties of streptomycin-resistant strain of shigella flexneri after prolonged preservation]. 201424544446
clinical and microbiological profiles of shigellosis in children.shigellosis presents with varied clinical features are dictated by the species involved, virulence factors of the strain, and the host immune status. we studied the species, virulence genes, and antibiotic susceptibility pattern of the shigella strains isolated from 33 children aged less than 12 years, with clinical features of shigellosis. identification and antibiotic sensitivity of shigella species were done using disc diffusion and e-test. multiplex pcr was done for the detection of virulenc ...201425895190
shigella flexneri: a three-year antimicrobial resistance monitoring of isolates in a children hospital, ahvaz, iran.shigellosis is an acute gastroenteritis that is one of the most common causes of morbidity and mortality in children with diarrhea in developing countries. the purpose of this study was to describe the distribution of shigella serogroups and serotypes and their antibacterial drug resistance profiles.201425802704
a large outbreak of shigellosis commencing in an internally displaced population, papua new guinea, 2013.the objective of this study was to investigate a large outbreak of shigellosis in papua new guinea that began in a camp for internally displaced persons before spreading throughout the general community.201425648967
structural characterization of a flexible two-domain protein in solution using small angle x-ray scattering and nmr data.multidomain proteins in which individual domains are connected by linkers often possess inherent interdomain flexibility that significantly complicates their structural characterization in solution using either nuclear magnetic resonance (nmr) spectroscopy or small-angle x-ray scattering (saxs) alone. here, we report a protocol for joint refinement of flexible multidomain protein structures against nmr distance and angular restraints, residual dipolar couplings, and saxs data. the protocol is ba ...201425456817
comparative proteomic analysis of outer membrane vesicles from shigella flexneri under different culture conditions.the production of outer membrane vesicles (omvs) is a common and regulated process of gram-negative bacteria. nonetheless, the processes of shigella flexneri omv production still remain unclear. s. flexneri is the causative agent of endemic shigellosis in developing countries. the congo red binding of strains is associated with increased infectivity of s. flexneri. therefore, understanding the modulation pattern of omv protein expression induced by congo red will help to elucidate the bacterial ...201425445584
the extant world war 1 dysentery bacillus nctc1: a genomic analysis.shigellosis (previously bacillary dysentery) was the primary diarrhoeal disease of world war 1, but outbreaks still occur in military operations, and shigellosis causes hundreds of thousands of deaths per year in developing nations. we aimed to generate a high-quality reference genome of the historical shigella flexneri isolate nctc1 and to examine the isolate for resistance to antimicrobials.201425441199
targeting of chromatin readers: a novel strategy used by the shigella flexneri virulence effector ospf to reprogram transcription.shigella flexneri, a gram-negative bacterium responsible of bacillary dysentery, uses multiple strategies to overcome host immune defense. we have decrypted how this bacterium manipulates host-cell chromatin binders to take control of immune gene expression. we found that ospf, an injected virulence factor previously identified as a repressor of immune gene expression, targets the chromatin reader hp1γ. heterochromatin protein 1 family members specifically recognize and bind histone h3 methylate ...201428357260
the shigella flexneri type 3 secretion system is required for tyrosine kinase-dependent protrusion resolution, and vacuole escape during bacterial dissemination.shigella flexneri is a human pathogen that triggers its own entry into intestinal cells and escapes primary vacuoles to gain access to the cytosolic compartment. as cytosolic and motile bacteria encounter the cell cortex, they spread from cell to cell through formation of membrane protrusions that resolve into secondary vacuoles in adjacent cells. here, we examined the roles of the type 3 secretion system (t3ss) in s. flexneri dissemination in ht-29 intestinal cells infected with the serotype 2a ...201425405985
time-resolved assembly of a nucleoprotein complex between shigella flexneri virf promoter and its transcriptional repressor h-ns.the virf gene of shigella, responsible for triggering the virulence cascade in this pathogenic bacterium, is transcriptionally repressed by the nucleoid-associated protein h-ns. the primary binding sites of h-ns within the promoter region of virf have been detected here by footprinting experiments in the presence of h-ns or its monomeric dna-binding domain (h-nsctd), which displays the same specificity as intact h-ns. of the 14 short dna fragments identified, 10 overlap sequences similar to the ...201425389261
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