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epidemiological study of shigellosis in an urban area of argentina.shigellosis represents one of the main causes of bloody diarrhoea in south america. this study aimed to establish the incidence of shigellosis in an urban zone of buenos aires, argentina, by examining the type of shigella and living conditions associated with this infection.201222505441
ongoing outbreak of shigella flexneri serotype 3a in men who have sex with men in england and wales, data from 2009-2011.diagnoses of shigella flexneri in the united kingdom (uk) are usually travel-related. however, since 2009, there has been an overall increase in uk-acquired cases. the health protection agency has been investigating a national outbreak of s. flexneri detected in 2011 and which is still ongoing. cases occurred mostly in men who have sex with men and were of serotype 3a. the investigation aimed at obtaining epidemiological data to inform targeted outbreak management and control.201222490381
comparison of the prevalence and changing resistance to nalidixic acid and ciprofloxacin of shigella between europe-america and asia-africa from 1998 to 2009.shigella is becoming an increasing public health problem due to development of multiple antimicrobial resistance, frequently resulting in treatment failure. a systematic review was conducted based on a literature search of computerised databases. random or fixed-effects models were used, based on the p-value considering the possibility of heterogeneity between studies, for meta-analysis. statistical analyses were performed using stata 10.0. in the area of asia-africa, resistance rates to nalidix ...201222483324
ultrastructural analysis of ipad at the tip of the nascent mxih type iii secretion apparatus of shigella flexneri.shigella flexneri is a gram-negative enteric pathogen that is the predominant cause of bacillary dysentery. shigella uses a type iii secretion system to deliver effector proteins that alter normal target cell functions to promote pathogen invasion. the type iii secretion apparatus (t3sa) consists of a basal body, an extracellular needle, and a tip complex that is responsible for delivering effectors into the host cell cytoplasm. ipad [ipa (invasion plasmid antigen)] is the first protein to local ...201222480614
structural characterization of closely related o-antigen lipopolysaccharide (lps) chain length regulators.the surface o-antigen polymers of gram-negative bacteria exhibit a modal length distribution that depends on dedicated chain length regulator periplasmic proteins (polysaccharide co-polymerases, pcps) anchored in the inner membrane by two transmembrane helices. in an attempt to determine whether structural changes underlie the o-antigen modal length specification, we have determined the crystal structures of several closely related pcps, namely two chimeric pcp-1 family members solved at 1.6 and ...201222437828
characterization of the promoter, mxie box and 5' utr of genes controlled by the activity of the type iii secretion apparatus in shigella flexneri.activation of the type iii secretion apparatus (t3sa) of shigella flexneri, upon contact of the bacteria with host cells, and its deregulation, as in ipab mutants, specifically increases transcription of a set of effector-encoding genes controlled by mxie, an activator of the arac family, and ipgc, the chaperone of the ipab and ipac translocators. thirteen genes carried by the virulence plasmid (ospb, ospc1, ospd2, ospd3, ospe1, ospe2, ospf, ospg, vira, ipah1.4, ipah4.5, ipah7.8 and ipah9.8) and ...201222427898
calpain activation by the shigella flexneri effector vira regulates key steps in the formation and life of the bacterium's epithelial niche.the enteropathogen shigella flexneri invades epithelial cells, leading to inflammation and tissue destruction. we report that shigella infection of epithelial cells induces an early genotoxic stress, but the resulting p53 response and cell death are impaired due to the bacterium's ability to promote p53 degradation, mainly through calpain protease activation. calpain activation is promoted by the shigella virulence effector vira and dependent on calcium flux and the depletion of the endogenous c ...201222423964
identification of the bile salt binding site on ipad from shigella flexneri and the influence of ligand binding on ipad structure.type iii secretion (tts) is an essential virulence factor for shigella flexneri, the causative agent of shigellosis. the shigella tts apparatus (ttsa) is an elegant nanomachine that is composed of a basal body, an external needle to deliver effectors into human cells, and a needle tip complex that controls secretion activation. ipad is at the tip of the nascent ttsa needle where it controls the first step of tts activation. the bile salt deoxycholate (doc) binds to ipad to induce recruitment of ...201222423359
the shigella flexneri effector ospi deamidates ubc13 to dampen the inflammatory response.many bacterial pathogens can enter various host cells and then survive intracellularly, transiently evade humoral immunity, and further disseminate to other cells and tissues. when bacteria enter host cells and replicate intracellularly, the host cells sense the invading bacteria as damage-associated molecular patterns (damps) and pathogen-associated molecular patterns (pamps) by way of various pattern recognition receptors. as a result, the host cells induce alarm signals that activate the inna ...201222407319
structure of a type iii secretion needle at 7-å resolution provides insights into its assembly and signaling mechanisms.type iii secretion systems of gram-negative bacteria form injection devices that deliver effector proteins into eukaryotic cells during infection. they span both bacterial membranes and the extracellular space to connect with the host cell plasma membrane. their extracellular portion is a needle-like, hollow tube that serves as a secretion conduit for effector proteins. the needle of shigella flexneri is approximately 50-nm long and 7-nm thick and is made by the helical assembly of one protein, ...201222388746
transmission and strain variation of shigella flexneri 4a after mass prophylaxis in a long-stay psychiatric centre.shigella flexneri 4a caused sustained outbreaks in a large long-stay psychiatric centre, taiwan, 2001-2006. trimethoprim-sulphamethoxazole (sxt) prophylaxis was administered in 2004. we recovered 108 s. flexneri 4a isolates from 83 symptomatic (including one caregiver) and 12 asymptomatic subjects (11 contacts, one caregiver). the isolates were classified into eight antibiogram types and 15 genotypes (six clusters) by using antimicrobial susceptibility testing and pulsed-field gel electrophoresi ...201322364591
outer membrane protein a (ompa) of shigella flexneri 2a links innate and adaptive immunity in a tlr2-dependent manner and involvement of il-12 and nitric oxide.we determine that ompa of shigella flexneri 2a is recognized by tlr2 and consequently mediates the release of proinflammatory cytokines and activates nf-κb in hek 293 cells transfected with tlr2. we also observe that in raw macrophages tlr2 is essential to instigate the early immune response to ompa via nf-κb activation and secretion of cytokines and no. consistent with these results, tlr2 knockdown using sirna abolishes the initiation of immune responses. processing and presentation of ompa dep ...201222343631
emergence of resistance to fluoroquinolones and third-generation cephalosporins in shigella flexneri subserotype 1c isolates from china.we report here on the first identification of shigella flexneri subserotype 1c in china. we also report the emergence of resistance to ciprofloxacin and third-generation cephalosporins in this subserotype 1c for the first time. isolates of seven strains circulating in china yielded three new sequence types and seven pulsed-field gel electrophoresis patterns, thus demonstrating the existence of high genetic diversity within the isolates. overall, the seven isolates showed reduced susceptibility t ...201222329572
the structures of coiled-coil domains from type iii secretion system translocators reveal homology to pore-forming toxins.many pathogenic gram-negative bacteria utilize type iii secretion systems (t3sss) to alter the normal functions of target cells. shigella flexneri uses its t3ss to invade human intestinal cells to cause bacillary dysentery (shigellosis) that is responsible for over one million deaths per year. the shigella type iii secretion apparatus is composed of a basal body spanning both bacterial membranes and an exposed oligomeric needle. host altering effectors are secreted through this energized unidire ...201222321794
characterization of sfpgda, a shigella flexneri peptidoglycan deacetylase required for bacterial persistence within polymorphonuclear neutrophils.peptidoglycan deacetylases protect the gram-positive bacteria cell wall from host lysozymes by deacetylating peptidoglycan. sequence analysis of the genome of shigella flexneri predicts a putative polysaccharide deacetylase encoded by the plasmidic gene orf185, renamed here sfpgda. we demonstrated a peptidoglycan deacetylase (pgd) activity with the purified sfpgda in vitro. to investigate the role sfpgda in virulence, we constructed a sfpgda mutant and studied its phenotype in vitro. the mutant ...201222307019
an expert panel report of a proposed scientific model demonstrating the effectiveness of antibacterial handwash products.in 2005, a us food and drug administration nonprescription drug advisory committee (ndac) review of consumer antiseptic handwash product studies concluded that the data regarding existing products failed to demonstrate any association between specific log reductions of bacteria achieved by antiseptic handwashing and reduction of infection. the ndac recommended that consumer antibacterial handwashing products should demonstrate a reduction in infection compared with non-antibacterial handwash pro ...201222300895
interaction of mxig with the cytosolic complex of the type iii secretion system controls shigella virulence.gram-negative bacteria use the type 3 secretion system (t3ss) to colonize host cells. t3sss are ring-shaped macromolecular complexes specific for the transport of effector molecules into host cells. it was recently suggested that a cytosolic ring-shaped protein complex delivers effector molecules to the t3ss. however, how transport of effector proteins is regulated is not known. here, we report the high-resolution x-ray crystal structure of the whole cytosolic domain of mxig (mxig(1-126)), a maj ...201222247334
a contribution of mdfa to resistance to fluoroquinolones in shigella flexneri.in this study, we measured the drug resistance conferred by mdfa mutations in two shigella flexneri strains. a mutant in mdfa genes was constructed by polymerase chain reaction-based, one-step inactivation of chromosomal genes. the antimicrobial susceptibility of parent and mutant strains to fluoroquinolones was determined by minimal inhibitory concentration (mics). the △mdfa mutants were somewhat more susceptible to fluoroquinolones than the parent strains. the low level changes in mics of the ...201124159476
shigellosis outbreak at addis ababa university: march-april 2010.between 2006 and 2008, there have been various reports of diarrhea with blood in ethiopia and also reports of shigelloses outbreaks in some parts of the country. in march 2010, addis ababa university (aau) technology campus reported occurrence of an outbreak of diarrheal illness among students.201123409399
antibacterial and cytotoxic activity of ethanol extract of mikania cordata (burm.f.) b.l. robinson leaves.the purpose of the present study to examine the antibacterial and cytotoxic properties of ethanol extract of leaves of mikania cordata (burm.f.) b.l. robinson. to determine antibacterial activities, the extract was tested against four gram positive and six gram negative bacteria at three concentrations (500, 800, 1000 μg disc(-1)) through disc diffusion method. the extract showed moderate antibacterial actions and that was increased by increasing the concentration of the sample. the maximum anti ...201124826008
surveillance of antibiotic susceptibility pattern among shigella flexneri strain isolated in nagpur district during three years period, january 2009-january 2012.in the few cases of childhood dirrhea that require the antimicrobial therapy, the correct choice of the drug depends on detailed previous knowledge of local strains and pattern of antimicrobial resistance. shigellosis is one of the most improtant examples of this group of intestinal infections. in order to establish such parameters in nagpur city, this study was carried out to determine the antimcrobial resistance profile of shigella flexneri isolated from patients suffering from diahhrea admitt ...201023051941
proinflammatory signal transduction pathway induced by shigella flexneri porins in caco-2 cells.the recognition of bacterial components on the intestinal epithelial cells occurs through the toll-like receptors and is followed by the induction of an effective innate immune response. we analyzed receptor expression and signaling pathways involved in activation of human colon adenocarcinoma cells after stimulation with porins and lps of shigella flexneri. we also analyzed the expression and production of some cytokines, of intercellular adhesion molecule-1, of antimicrobial peptides human β-d ...200924031417
molecular epidemiology of shigella spp strains isolated in two different metropolitam areas of southeast brazil.shigella spp., the human pathogen responsible for shigellosis, is highly infectious even at low levels. the incidence rate of shigellosis varies with geographical distribution, location human development index, and age groups, being higher among children aged under 5 years. in brazil, a few works indicate that shigellosis cases are underestimated, with s. flexneri and s. sonnei strains being the major agents responsible for the shigellosis cases. the present study used pulsed field gel electroph ...200924031415
the nucleotide sequence of shigella flexneri 1a: a common indian isolate.we report complete sequences of 2 genes of s.flexneri 1a an indian isolate for the first time. shigella is causative agent of shigellosis or bacillary dysentery. genomic library was constructed by shotgun approach. sequencing was carried out using big dye terminator chemistry using abi 3730 48 capillary dna analyzer. 170 recombinants were subjected to nucleotide sequencing. sequence data was analyzed, of these 2 clones showed presence of complete genes out of the total clones sequenced. annotati ...200923105823
shigella flexneri encephalopathy in a male child. 200622266506
antibacterial acivity of the essential oil of lippie nodiflora.the plant lippia nodiflora (family-verbenaceae) has medicinal properties and particularly used as an antidandruff agent. the essential oil of the plant was tested for its antibacterial activity against both gram positive and gram negative bacteria. it showed good activity and compared with standard neomycin sulphate. however, it was inactive in the case of shigella flexneri.199622556775
[result of serological studies of standard cultures of shigella flexneri obtained from various museum collections]. 195324543446
[data on biological characteristics of shigella flexneri]. 195324543445
antibacterial effects of lactobacillus isolates of curd and human milk origin against food-borne and human pathogens.this study was undertaken to assess the antibacterial efficacy of lactobacilli isolated from curd and human milk samples. identities of thirty-one different lactobacilli (20 from curd and 11 from human milk) were confirmed by genus-specific pcr and 16s rrna-based sequencing. these strains belonged to five species, lactobacillus casei, l. delbrueckii, l. fermentum, l. plantarum, and l. pentosus. antibacterial activities of cell-free supernatants (cfss) of all the lactobacillus isolates were estim ...201728401466
antiprotozoal, antibacterial and antidiarrheal properties from the flowers of chiranthodendron pentadactylon and isolated flavonoids.chiranthodendron pentadactylon larreat. (sterculiaceae) is a mexican plant used in traditional medicine for the treatment of heart disease symptoms and infectious diarrhea.201728539715
campylobacter jejuni as a cause of diarrhoea.this study was carried out to isolate and identify campylobacter jejuni from stool samples of patients suffering from diarrhoea. the study spanned a two-year period and c. jejuni was isolated in 10 (4.5%) out of 220 patients of diarrhoea] disorders. in samples of stool collected from 50 healthy individuals, c. jejuni was isolated in one (2%) case. further, to isolate other enteropathogens alongwith c. jejuni, procedures were undertaken simultaneously to identify salmonella, shigella and vibrio c ...199728769509
flagellar expression in clinical isolates of non-typeable haemophilus influenzae.haemophilus influenzae is a commensal organism found in the upper respiratory tract of humans. when h. influenzae becomes a pathogen, these bacteria can move out of their commensal niche and cause multiple respiratory tract diseases such as otitis media, sinusitis, conjunctivitis and bronchitis in children, and chronic obstructive pulmonary disease in adults. however, h. influenzae is currently considered a non-flagellate bacterium.201728513418
antimicrobial activity of endophytic bacterial populations isolated from medical plants of iran.endophytic actinobacteria colonize inside the plant tissues without causing damages to the host plant. since these microorganisms colonize in the different parts of plants and can stop plant disease, they have been applied as biological agents for controlling human diseases. the aim of this study was molecular identification and measuring the antimicrobial activity of endophytic actinomycetes isolated from medicinal plants of iran.201728775818
cyclohexene-fused 1,3-oxazines with selective antibacterial and antiparasitic action and low cytotoxic effects.oxazine derivatives, a class of heterocyclic compounds, exhibit a variety of biological properties, such as anticonvulsant and antitumor activities. in this study, we evaluated the effect of two cyclohexene-fused 1,3-oxazines (cis‑1-benzyl-n-phenyl-1,4,4a,5,8,8a-hexahydro-3,1-benzoxazin-2-imine (1) and trans‑n-phenyl-1,4,4a,5,8,8a-hexahydro-3,1-benzoxazin-2-imine (2)) in cultures of bacillus cereus, enterococcus faecalis, escherichia coli, klebsiella pneumoniae, salmonella enterica, serratia mar ...201728755871
use of whey as a culture medium for bacillus clausii for the production of protein hydrolysates with antimicrobial and antioxidant activity.the use of whey as a natural culture medium to produce hydrolysates with antimicrobial from bacillus clausii is the objective of this research. the fermentation process was carried out at 25 ℃ for five days, where proteolytic activity, soluble peptides quantification, and antimicrobial activity using the disc diffusion method were determined every day. the fermented whey reached values ​​of proteolytic activity between 90 and 260 u ml(-1) and a production of soluble peptides between 100 and 2070 ...201728816527
bipc, a predicted burkholderia pseudomallei type 3 secretion system translocator protein with actin binding activity.burkholderia pseudomallei is an intracellular bacterial pathogen and the causative agent of melioidosis, a severe disease of humans and animals. like other clinically important gram-negative bacteria, fundamental to b. pseudomallei pathogenesis is the bsa type iii secretion system. the bsa system injects bacterial effector proteins into the cytoplasm of target host cells subverting cellular pathways for the benefit of the bacteria. it is required for invasion of non-phagocytic host cells, escape ...201728770177
type iii secretion in the melioidosis pathogen burkholderia pseudomallei.burkholderia pseudomallei is a gram-negative intracellular pathogen and the causative agent of melioidosis, a severe disease of both humans and animals. melioidosis is an emerging disease which is predicted to be vastly under-reported. type iii secretion systems (t3sss) are critical virulence factors in gram negative pathogens of plants and animals. the genome of b. pseudomallei encodes three t3sss. t3ss-1 and -2, of which little is known, are homologous to hrp2 secretion systems of the plant pa ...201728664152
colorimetric sensing of toxic metal and antibacterial studies by using bioextract synthesized silver nanoparticles.here, we report the simple and cost effective colorimetric technique for the determination of toxic metals (hg(2+)) in aqueous sample by using bioextract silver nanoparticles (agnps). the indigenous agnps were synthesised by green and ecologically friendly style using extract of fig (ficus carica) leaf. the synthesized agnps were confirmed by uv-vis spectroscopy, ft-ir spectroscopy, and scanning electron microscopy methods. the synthesis of agnps was observed by its colour changing from light ye ...201728748516
altered antibacterial activity of curcumin in the presence of serum albumin, plasma and whole blood.antibacterial effect is one of the major therapeutic activities of plant-derived curcumin. this work evaluated the effect of serum albumin, human plasma, and whole blood on the in vitro activity of curcumin against eight clinical bacterial isolates by standard broth microdilution and plate-counting methods. toxicological effects of curcumin towards human red blood cells (rbcs) and peripheral blood mononuclear cells (pbmcs) were also investigated. curcumin exhibited weak activity against gram-neg ...201728649069
antibacterial activity of crude extracts of some south african medicinal plants against multidrug resistant etiological agents of diarrhoea.this study evaluated the antibacterial activity of some plants used in folklore medicine to treat diarrhoea in the eastern cape province, south africa.201728629407
antimicrobial, anticancer, and antioxidant compounds from premna resinosa growing in saudi arabia.premna resinosa (hochst.) schauer (lamiaceae) is used in many places to treat bronchitis, respiratory illness and convulsions of the rib cage.201728508699
dna aptamer identification and characterization for e. coli o157 detection using cell based selex method.escherichia coli (e. coli) o157:h7 is a foodborne pathogen that causes symptoms in humans. its rapid identification should be considered to avoid toxic effects of the pathogen. in this study, systematic evolution of ligands by exponential enrichment using whole cells (cell-selex) method was used for recognizing e. coli strain, o157 by single-stranded dna library of aptamer. nine rounds of cell-selex procedure were applied using o157, as a whole-cell target, with o42, k12, top10, dh5α e. coli cel ...201728818557
an attenuated shigella mutant lacking the rna-binding protein hfq provides cross-protection against shigella strains of broad serotype.few live attenuated vaccines protect against multiple serotypes of bacterial pathogen because host serotype-specific immune responses are limited to the serotype present in the vaccine strain. here, immunization with a mutant of shigella flexneri 2a protected guinea pigs against subsequent infection by s. dysenteriae type 1 and s. sonnei strains. this deletion mutant lacked the rna-binding protein hfq leading to increased expression of the type iii secretion system via loss of regulation, result ...201728727722
role of the virulence plasmid in acid resistance of shigella flexneri.virulence plasmid (vp) acquisition was a key step in the evolution of shigella from a non-pathogenic escherichia coli ancestor to a pathogenic genus. in addition, the co-evolution and co-ordination of chromosomes and vps was also a very important step in the evolutionary process. to investigate the cross-talk between vps and bacterial chromosomes, we analyzed the expression profiles of protein complexes and protein monomers in three wild-type shigella flexneri strains and their corresponding vp ...201728440329
nasal delivery of protollin-adjuvanted h5n1 vaccine induces enhanced systemic as well as mucosal immunity in mice.sporadic, yet frequent human infections with avian h5n1 influenza a viruses continue to pose a potential pandemic threat. poor immunogenicity of unadjuvanted h5n1 vaccines warrants developing novel adjuvants and formulations as well as alternate delivery systems to improve their immunogenicity and efficacy. here, we show that protollin, a nasal adjuvant composed of neisseria meningitides outer membrane proteins non-covalently linked to shigella flexneri 2a lipopolysaccharide, is a potent nasal a ...201728499553
antimicrobial natural product research: a review from a south african perspective for the years 2009-2016.this review provides information on the antimicrobial research which has taken place on south african natural products for the last eight years (2009-2016). this important field is the backbone of all studies involving the use of medicinal plants against infectious diseases and hence can form the mainstay for future studies.201728694104
stand-alone eal domain proteins form a distinct subclass of eal proteins involved in regulation of cell motility and biofilm formation in enterobacteria.the second messenger cyclic dimeric gmp (c-di-gmp) is almost ubiquitous among bacteria as are the c-di-gmp turnover proteins, which mediate the transition between motility and sessility. eal domain proteins have been characterized as c-di-gmp-specific phosphodiesterases. while most eal domain proteins contain additional, usually n-terminal, domains, there is a distinct family of proteins with stand-alone eal domains, exemplified by salmonella enterica serovar typhimurium proteins stm3611 (yhjh/p ...201728652301
listeria monocytogenes and shigella flexneri activate the nlrp1b inflammasome.activation of the innate immune receptor nlrp1b leads to the formation of an inflammasome, which induces autoproteolytic processing of pro-caspase-1, and ultimately to the release of inflammatory cytokines and to the execution of pyroptosis. one of the signals to which nlrp1b responds is metabolic stress that occurs in cells deprived of glucose or treated with metabolic inhibitors. nlrp1b might, therefore, sense microbial infection as intracellular pathogens such as listeria monocytogenes and sh ...201728808162
development of biopolymer composite films using a microfluidization technique for carboxymethylcellulose and apple skin particles.biopolymer films based on apple skin powder (asp) and carboxymethylcellulose (cmc) were developed with the addition of apple skin extract (ase) and tartaric acid (ta). asp/cmc composite films were prepared by mixing cmc with asp solution using a microfluidization technique to reduce particle size. then, various concentrations of ase and ta were incorporated into the film solution as an antioxidant and an antimicrobial agent, respectively. fourier transform infrared (ftir), optical, mechanical, w ...201728617325
comparative genomic and phylogenetic analysis of a shiga toxin producing shigella sonnei (stss) strain.shigella strains are important agents of bacillary dysentery, and in recent years shigella sonnei has emerged as the leading cause of shigellosis in industrialized and rapidly developing countries. more recently, several s. sonnei and shigella flexneri strains producing shiga toxin (stx) have been reported from sporadic cases and from an outbreak in america. in the present study we aimed to shed light on the evolution of a recently identified shiga toxin producing s. sonnei (stss) isolated in eu ...201728611956
evaluation of microplate immunocapture method for detection of vibrio cholerae, salmonella typhi and shigella flexneri from food.improved methods with better separation and concentration ability for detection of foodborne pathogens are in constant need. the aim of this study was to evaluate microplate immunocapture (ic) method for detection of salmonella typhi, shigella flexneri and vibrio cholerae from food samples to provide a better alternative to conventional culture based methods.201728851288
lubac-synthesized linear ubiquitin chains restrict cytosol-invading bacteria by activating autophagy and nf-κb.cell-autonomous immunity relies on the ubiquitin coat surrounding cytosol-invading bacteria functioning as an 'eat-me' signal for xenophagy. the origin, composition and precise mode of action of the ubiquitin coat remain incompletely understood. here, by studying salmonella typhimurium, we show that the e3 ligase lubac generates linear (m1-linked) polyubiquitin patches in the ubiquitin coat, which serve as antibacterial and pro-inflammatory signalling platforms. lubac is recruited via its subuni ...201728481331
genomic analysis and resistance mechanisms in shigella flexneri 2a strain 301.shigella flexneri is one of the most prominent pathogenic bacteria in developing countries. in the battle against shigellosis and other bacterial diseases, antibiotic resistance has become an increasing global public health threat. although the serious phenomenon of multidrug resistance (mdr) has been identified as one of the top three burdens on human health, resistance mechanisms are still poorly understood at the molecular level. in this study, we analyzed genomic data and the evolution of re ...201728853989
cardiolipin synthesis and outer membrane localization are required for shigella flexneri virulence.cardiolipin, an anionic phospholipid that resides at the poles of the inner and outer membranes, is synthesized primarily by the putative cardiolipin synthase clsa in shigella flexneri an s. flexneri clsa mutant had no cardiolipin detected within its membrane, grew normally in vitro, and invaded cultured epithelial cells, but it failed to form plaques in epithelial cell monolayers, indicating that cardiolipin is required for virulence. the clsa mutant was initially motile within the host cell cy ...201728851846
single-domain antibodies pinpoint potential targets within shigella invasion plasmid antigen d of the needle tip complex for inhibition of type iii secretion.numerous gram-negative pathogens infect eukaryotes and use the type iii secretion system (t3ss) to deliver effector proteins into host cells. one important t3ss feature is an extracellular needle with an associated tip complex responsible for assembly of a pore-forming translocon in the host cell membrane. shigella spp. cause shigellosis, also called bacillary dysentery, and invade colonic epithelial cells via the t3ss. the tip complex of shigella flexneri contains invasion plasmid antigen d (ip ...201728842484
vaccination with shigella flexneri 2a conjugate induces type 2a and cross-reactive type 6 antibodies in humans but not in mice.shigella flexneri (s. flexneri) 6 has emerged as an important cause of shigellosis. our efficacy study of shigella sonnei and s. flexneri 2a o-specific polysaccharide (o-sp) conjugates in 1-4year-olds had too few s. flexneri 2a cases for efficacy evaluation but surprisingly showed protection of 3-4year-olds, s. flexneri 2a-recipients, from s. flexneri 6 infection. to investigate this cross-protection antibodies to both shigella types were investigated in all sera remaining from previous studies. ...201728797729
inhibition of shigella sonnei and shigella flexneri in hummus using citric acid and garlic extract.hummus (chickpea dip) is a ready-to-eat product that may pose a significant risk to human if pathogens are present. several organisms including shigella spp. have been isolated from hummus. however, studies on the survival and inhibition of shigella spp. in food are scarce. this study investigated the growth pattern of sh. sonnei and sh. flexneri in hummus at different temperatures (4, 10, and 24 °c). additionally, the inhibitory activity of different concentrations of citric acid (ca) (0.5%, 1. ...201728732128
effective protection of mice against shigella flexneri with a new self-adjuvant multicomponent vaccine.the aim of this study was to develop an immunogenic protective product against shigella flexneri by employing a simple and safe heat treatment-based strategy.201728721849
septins restrict inflammation and protect zebrafish larvae from shigella infection.shigella flexneri, a gram-negative enteroinvasive pathogen, causes inflammatory destruction of the human intestinal epithelium. infection by s. flexneri has been well-studied in vitro and is a paradigm for bacterial interactions with the host immune system. recent work has revealed that components of the cytoskeleton have important functions in innate immunity and inflammation control. septins, highly conserved cytoskeletal proteins, have emerged as key players in innate immunity to bacterial in ...201728650995
characterization of extended-spectrum β-lactamase genes of shigella flexneri isolates with fosfomycin resistance from patients in china.the emergence of fosfomycin resistance and extended-spectrum β-lactamase (esbl) genes is a serious threat to public health and a new challenge in shigellosis treatment. the purpose of this study was to identify fosfomycin resistance and characterize β-lactamase genes in fos-carrying isolates of shigella flexneri from patients in china.201728643490
siga-shigella immune complexes interact with dectin-1 and signr3 to differentially regulate mouse peyer's patch and mesenteric lymph node dendritic cell's responsiveness.in addition to contributing to immune exclusion at mucosal surfaces, secretory iga (siga) made of polymeric iga and secretory component is able to selectively reenter via microfold cells into peyer's patches (pps) present along the intestine and to associate with dendritic cells (dcs) of the cd11c(+)cd11b(+)mhcii(+)f4/80(-)cd8(-)phenotype in the subepithelial dome region and the draining mesenteric lymph nodes (mlns). however, the nature of the receptor(s) for siga on murine pp and mln dcs is un ...201728587925
trappc13 modulates autophagy and the response to golgi stress.tether complexes play important roles in endocytic and exocytic trafficking of lipids and proteins. in yeast, the multisubunit transport protein particle (trapp) tether regulates endoplasmic reticulum (er)-to-golgi and intra-golgi transport and is also implicated in autophagy. in addition, the trapp complex acts as a guanine nucleotide exchange factor (gef) for ypt1, which is homologous to human rab1a and rab1b. here, we show that human trappc13 and other trapp subunits are critically involved i ...201728536105
genome-wide identification of potential drug target in enterobacteriaceae family: a homology-based method.the enterobacteriaceae is a large family of gram-negative, facultative anaerobic, non-spore forming rod-shaped bacteria that includes harmless and pathogenic organisms. the emergence and development of drug resistance in enterobacteriaceae is complicating the treatment of serious infections. the aim of this study is to predict and characterize putative drug targets in enterobacteriaceae family employing a homology-based computational method. the final putative drug targets were qualitatively cha ...201728520499
innate recognition of intracellular bacterial growth is driven by the tifa-dependent cytosolic surveillance pathway.intestinal epithelial cells (iecs) act as sentinels for incoming pathogens. cytosol-invasive bacteria, such as shigella flexneri, trigger a robust pro-inflammatory nuclear factor κb (nf-κb) response from iecs that is believed to depend entirely on the peptidoglycan sensor nod1. we found that, during shigella infection, the traf-interacting forkhead-associated protein a (tifa)-dependent cytosolic surveillance pathway, which senses the bacterial metabolite heptose-1,7-bisphosphate (hbp), functions ...201728514661
genome sequence of shigella flexneri strain sp1, a diarrheal isolate that encodes an extended-spectrum β-lactamase (esbl).shigellosis is the most common cause of gastrointestinal infections in developing countries. in china, the species most frequently responsible for shigellosis is shigella flexneri. s. flexneri remains largely unexplored from a genomic standpoint and is still described using a vocabulary based on biochemical and serological properties. moreover, increasing numbers of esbl-producing shigella strains have been isolated from clinical samples. despite this, only a few cases of esbl-producing shigella ...201728499446
in vitro resistance selection in shigella flexneri by azithromycin, ceftriaxone, ciprofloxacin, levofloxacin, and moxifloxacin.shigella flexneri continues to be a major cause of diarrhea-associated illness, and increasing resistance to first-line antimicrobials complicates the treatment of infections caused by this pathogen. we investigated the pharmacodynamics of current antimicrobial treatments for shigellosis to determine the likelihood of resistance promotion with continued global antimicrobial use. the mutant prevention concentration (mpc) and mutant selection window (msw) were determined for azithromycin, ceftriax ...201728483960
virf relieves the transcriptional attenuation of the virulence gene icsa of shigella flexneri affecting the icsa mrna-rnag complex formation.virf is the master activator of virulence genes of shigella and its expression is required for the invasion of the human intestinal mucosa by pathogenic bacteria. virf was shown to directly activate the transcription of virb and icsa, which encode two essential proteins involved in the pathogenicity process, by binding their promoter regions. in this study, we demonstrate by band shift, enzymatic probing and cross-linking experiments that virf, in addition to dna, can also bind the icsa transcri ...201728458662
genome sequencing analysis of atypical shigella flexneri isolated in korea.an atypical shigella flexneri strain with a plural agglutination pattern [i.e., reacting not only with serum samples containing type antigen ii but also with serum samples containing group antigens (3)4 and 7(8)] was selected for genome sequencing, with the aim of obtaining additional comparative information about such strains.201728443228
analysis of host microrna function uncovers a role for mir-29b-2-5p in shigella capture by filopodia.micrornas play an important role in the interplay between bacterial pathogens and host cells, participating as host defense mechanisms, as well as exploited by bacteria to subvert host cellular functions. here, we show that micrornas modulate infection by shigella flexneri, a major causative agent of bacillary dysentery in humans. specifically, we characterize the dual regulatory role of mir-29b-2-5p during infection, showing that this microrna strongly favors shigella infection by promoting bot ...201728394930
cnbp acts as a key transcriptional regulator of sustained expression of interleukin-6.the transcription of inflammatory genes is an essential step in host defense activation. here, we show that cellular nucleic acid-binding protein (cnbp) acts as a transcription regulator that is required for activating the innate immune response. we identified specific cnbp-binding motifs present in the promoter region of sustained inflammatory cytokines, thus, directly inducing the expression of target genes. in particular, lipopolysaccharide (lps) induced cnbp expression through an nf-κb-depen ...201728168305
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