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recovery and characterization of environmental variants of shigella flexneri from surface water in bangladesh.little is known about the distribution, survival, and transmission of shigella in environmental surface waters. to gain more insight into the environmental biology of shigella we isolated five bacterial strains serotyped as shigella flexneri 2b from a freshwater lake in bangladesh using a modified nutrient broth supplemented with nucleic acid bases. the biochemical properties of the isolates, including inability to ferment lactose and a negative lysine decarboxylase test, indicated common physio ...201121826486
antimicrobial activity of gynostemma pentaphyllum extracts against fungi producing aflatoxin and fumonisin and bacteria causing diarrheal disease.gynostemma pentaphyllum was investigated to determine its antimicrobial activities against human.and animal pathogens that produce aflatoxin, fumonisin, and diarrheal disease. the fungi were aspergillusflavus, aspergillus parasiticus and fusarium verticillioides. the bacteria were vibrio, salmonella, shigella, escherichia coli and staphylococcus aureus. g. pentaphyllum was extracted by five different methods. the obtained extracts were designated extracts a, b, c, d and e. the results of the ant ...201121706950
a new class of 2-(4-cyanophenyl amino)-4-(6-bromo-4-quinolinyloxy)-6-piperazinyl (piperidinyl)-1,3,5-triazine analogues with antimicrobial/antimycobacterial activity.this study presents the synthesis and in vitro pharmacological evaluations of novel 2-(4-cyanophenyl amino)-4-(6-bromo-4-quinolinyloxy)-6-piperazinyl (piperidinyl)-1,3,5-triazines. the title compounds were assayed for their in vitro antimicrobial activity against eight bacteria (staphylococcus aureus, bacillus cereus, escherichia coli, pseudomonas aeruginosa, klebsiella pneumoniae, salmonella typhi, proteus vulgaris, shigella flexneria) and four fungi (aspergillus niger, aspergillus fumigatus, a ...201121740100
structural and functional studies on the n-terminal domain of the shigella type iii secretion protein mxig.mxig is a single-pass membrane protein that oligomerizes within the inner membrane ring of the shigella flexneri type iii secretion system (t3ss). the mxig n-terminal domain (mxig-n) is the predominant cytoplasmic structure; however, its role in t3ss assembly and secretion is largely uncharacterized. we have determined the solution structure of mxig-n residues 6-112 (mxig-n(6-112)), representing the first published structure of this t3ss domain. the structure shows strong structural homology to ...201121733840
a multifactor regulatory circuit involving h-ns, virf and an antisense rna modulates transcription of the virulence gene icsa of shigella flexneri.the icsa gene of shigella encodes a structural protein involved in colonization of the intestinal mucosa by bacteria. this gene is expressed upon invasion of the host and is controlled by a complex regulatory circuit involving the nucleoid protein h-ns, the arac-like transcriptional activator virf, and a 450ôçënt antisense rna (rnag) acting as transcriptional attenuator. we investigated on the interplay of these factors at the molecular level. dnase i footprints reveal that both h-ns and virf bi ...201121724612
epidemiology and molecular mechanism of integron-mediated antibiotic resistance in shigella.integrons are gene capture and expression systems that are characterized by the presence of an integrase gene. this encodes an integrase, a recombined site, and a promoter. they are able to capture gene cassettes from the environment and incorporate them using site-specific recombination. the role of integrons and gene cassettes in the dissemination of multidrug resistance in gram-negative bacteria is significant. in shigella species, antimicrobial resistance is often associated with the presenc ...201121842348
antibacterial dimeric copper(ii) complexes with chromone-derived compounds.a new series of six chromone-derived compounds and their cu(ii) complexes have been synthesized and characterized by their physical, spectral and analytical data. the ligands and their cu(ii) complexes were screened for their in vitro antibacterial activity against four gram-negative (escherichia coli, pseudomonas aeruginosa, salmonella typhi, shigella flexneri) and two gram-positive (bacillus subtilis, staphylococcus aureus) bacterial strains by agar-well diffusion method. the ligands were foun ...201121699463
espg of enteropathogenic and enterohemorrhagic e. coli binds the golgi matrix protein gm130 and disrupts the golgi structure and function.the enteric pathogens enteropathogenic escherichia coli (epec), enterohaemorrhagic e. coli (ehec) and shigella flexneri all translocate at least one effector protein of the espg protein family into host cells via a type iii secretion system (t3ss). the espg family comprises espg, espg2 and vira. from a y2h screen, we identified the golgi matrix protein gm130 as a potential binding partner of espg. we confirmed espg:gm130 protein interaction by affinity co-purification. in co-immunoprecipitation ...201121740499
in vivo versus in vitro protein abundance analysis of shigella dysenteriae type 1 reveals changes in the expression of proteins involved in virulence, stress and energy metabolism.shigella dysenteriae serotype 1 (sd1) causes the most severe form of epidemic bacillary dysentery. quantitative proteome profiling of shigella dysenteriae serotype 1 (sd1) in vitro (derived from lb cell cultures) and in vivo (derived from gnotobiotic piglets) was performed by 2d-lc-ms/ms and apex, a label-free computationally modified spectral counting methodology.201121702961
the rickettsia surface cell antigen 4 applies mimicry to bind to and activate vinculin.pathogenic rickettsiae species cause high morbidity and mortality, especially r. prowazekii the causative agent of typhus. like many intracellular pathogens, rickettsiae exploit the cytoskeleton to enter and spread within the host cell. here we report that the cell surface antigen sca4 of rickettsiae colocalizes with vinculin in cells at sites of focal adhesions, and that sca4 binds to and activates vinculin through two vinculin binding sites (vbss) that are conserved across all rickettsia. rema ...201121841197
the yersinia enterocolitica type 3 secretion system (t3ss) as toolbox for studying the cell biological effects of bacterial rho gtpase modulating t3ss effector proteins.the bacterial effector proteins ipgb(1) and ipgb(2) of shigella and map of escherichia coli activate the rho gtpases rac1, rhoa and cdc42, respectively, whereas yope and yopt of yersinia inhibit these rho family gtpases. we established a yersinia toolbox which allows to study the cellular effects of these effectors in different combinations in the context of yersinia type 3 secretion system (ysc)-t3ss-mediated injection into hela cells. for this purpose hybrid proteins were constructed by fusion ...201121718421
epidemiology and outcome of shigella, salmonella and campylobacter infections in travellers returning from the tropics with fever and diarrhoea.during a study on fever after a stay in the tropics, we aimed at investigating the epidemiology and outcome of invasive bacterial enteritis due to shigella, salmonella or campylobacter spp. in patients diagnosed with febrile traveller's diarrhoea.201121837926
physicochemical and microbiological assessment of recreational and drinking waters.the present study was aimed to make an assessment of health risk due to pollution and human pathogenic bacteria associated with the recreational and drinking water sources in twin densely populated holy indian cities ayodhya and faizabad. though physicochemical studies revealed that the water available in the area is under recommended limits for human use, it is unsafe on account of poor microbiological quality of surface and ground water in the region. the most probable number (mpn) test result ...201121713494
a multi-center randomized trial to assess the efficacy of gatifloxacin versus ciprofloxacin for the treatment of shigellosis in vietnamese children.the bacterial genus shigella is the leading cause of dysentery. there have been significant increases in the proportion of shigella isolated that demonstrate resistance to nalidixic acid. while nalidixic acid is no longer considered as a therapeutic agent for shigellosis, the fluoroquinolone ciprofloxacin is the current recommendation of the world health organization. resistance to nalidixic acid is a marker of reduced susceptibility to older generation fluoroquinolones, such as ciprofloxacin. w ...201121829747
differential response of the human renal proximal tubular epithelial cell line hk-2 to shiga toxin types 1 and 2.shiga toxins (stxs) are expressed by the enteric pathogens shigella dysenteriae serotype 1 and certain serotypes of escherichia coli. stx-producing bacteria cause bloody diarrhea with the potential to progress to acute renal failure. stxs are potent protein synthesis inhibitors and are the primary virulence factors responsible for renal damage that may follow diarrheal disease. we explored the use of the immortalized human proximal tubule epithelial cell line hk-2 as an in vitro model of stx-ind ...201121708996
investigating the global genomic diversity of escherichia coli using a multi-genome dna microarray platform with novel gene prediction strategies.abstract:201121733163
antisense inhibition of gene expression and growth in gram-negative bacteria by cell-penetrating peptide conjugates of peptide nucleic acids targeted to rpod gene.gram-negative bacteria (gnb) cause common and severe hospital- and community-acquired infections with a high incidence of multidrug resistance (mdr) and mortality. the emergence and spread of mdr-gnb strains limit therapeutic options and highlight the need to develop new therapeutic strategies. in this study, the peptide (rxr)(4)xb- and (kff)(3)k-conjugated peptide nucleic acids (ppnas) were developed to target rpod, which encodes an rna polymerase primary σ(70) that is thought to be essential f ...201122000398
bacteriological assessment of drinking water supply options in coastal areas of bangladesh.this study was conducted to assess the bacteriological quality of alternative drinking water supply options in southwest coastal areas of bangladesh. a total of 90 water samples were collected during both dry and wet seasons from household based rainwater harvesting systems (rwhss), community based rain water harvesting systems (crwhss), pond-sand filters (psfs) and ponds. the samples were evaluated for faecal coliform, escherichia coli and heterotrophic plate count, as well as vibrio cholerae, ...201121942205
Natural Products Modulate Shigella-Host Cell Interaction.This study focussed on identifying possible new options derived from natural sources for the treatment of bacterial infections. Several natural products were investigated for their potential in modulating Shigella-host cell interaction. The proliferation of Shigella sonnei was effectively inhibited inside HEp-2 cells in the presence of 4-methoxycinnamic acid and propolin D. Propolin D also significantly reduced the apopotosis of infected macrophage-like U937 cells, and moderately reduced the sec ...201121719574
atomic structure of bacteriophage sf6 tail needle knob.podoviridae are double-stranded dna bacteriophages that use short, non-contractile tails to adsorb to the host cell surface. within the tail apparatus of p22-like phages, a dedicated fiber known as the "tail needle" likely functions as a cell envelope-penetrating device to promote ejection of viral dna inside the host. in sf6, a p22-like phage that infects shigella flexneri, the tail needle presents a c-terminal globular knob. this knob, absent in phage p22 but shared in other members of the p22 ...201121705802
comparative sequence analysis of acid sensitive/resistance proteins in escherichia coli and shigella flexneri.the molecular basis for the survival of bacteria under extreme conditions in which growth is inhibited is a question of great current interest. a preliminary study was carried out to determine residue pattern conservation among the antiporters of enteric bacteria, responsible for extreme acid sensitivity especially in escherichia coli and shigella flexneri. here we found the molecular evidence that proved the relationship between e. coli and s. flexneri. multiple sequence alignment of the gadc c ...200721670792
chemical and antidiarrheal studies of plinia cauliflora.plinia cauliflora (mart.) kausel, widespread in south america, has edible fruits, and its bark is commonly used against diarrhea and other disorders, on account of its astringency. because diarrhea is still one of the most important causes of illness and death among children in developing countries, where the population turns to traditional medicine for its treatment, the present study determined the composition of fruit and leaf extracts of p. cauliflora, analyzed the activity against diarrhea ...201121861716
gene decay in shigella as an incipient stage of host-adaptation.background: many facultative bacterial pathogens have undergone extensive gene decay processes, possibly due to lack of selection pressure during evolutionary conversion from free-living to intracellular lifestyle. shigella, the causative agents of human shigellosis, have arisen from different e. coli-like ancestors independently by convergent paths. as these bacteria all have lost large numbers of genes by mutation or deletion, they can be used as ideal models for systematically studying the pr ...201122110755
Within-species lateral genetic transfer and the evolution of transcriptional regulation in Escherichia coli and Shigella.Changes in transcriptional regulation underlie many of the phenotypic differences observed within and between species of bacteria. Lateral genetic transfer (LGT) can significantly impact the transcription factor (TF) genes which drive these transcriptional changes. Although much emphasis has been placed on LGT of intact genes, the units of transfer and recombination do not necessarily correspond to regions delineated by exact gene boundaries. Here we apply phylogenetic and network-based methods ...201122035052
Mucosal immunization with Shigella flexneri outer membrane vesicles induced protection in mice.Vaccination appears to be the only rational prophylactic approach to control shigellosis. Unfortunately, there is still no safe and efficacious vaccine available. We investigated the protection conferred by a new vaccine containing outer membrane vesicles (OMVs) from Shigella flexneri with an adjuvant based on nanoparticles in an experimental model of shigellosis in mice. OMVs were encapsulated in poly(anhydride) nanoparticles prepared by a solvent displacement method with the copolymer PMV/MA. ...201121911022
Differentiation between Shigella, enteroinvasive Escherichia coli (EIEC) and noninvasive Escherichia coli.Shigella causes bacillary dysentery and is classified into four species based on their antigen characteristics. This classification does not reflect genetic relatedness; in fact, Shigella species are so related to Escherichia coli , they should be classified as one distinctive species in the genus Escherichia. The differentiation of Shigella and E. coli is even more complicated with the description of enteroinvasive E. coli (EIEC). EIEC are strains that possess some of the biochemical characteri ...201121901636
Genesis of a novel Shigella flexneri serotype by sequential infection of serotype-converting bacteriophages SfX and SfI.ABSTRACT: BACKGROUND: Shigella flexneri is the major pathogen causing bacillary dysentery. Fifteen serotypes have been recognized up to now. The genesis of new S. flexneri serotypes is commonly mediated by serotype-converting bacteriophages. Untypeable or novel serotypes from natural infections had been reported worldwide but have not been generated in laboratory. RESULTS: A new S. flexneri serotype-serotype 1 d was generated when a S. flexneri serotype Y strain (native LPS) was sequentially in ...201122208551
[Investigation of verotoxigenic escherichia coli O157:H7 incidence in gastroenteritis patients].Escherichia coli O157:H7 is the most common serotype among verotoxigenic E.coli (VTEC) strains that cause haemolytic uremic syndrome. Although sporadic VTEC cases originating from Turkey and small outbreaks have been reported from our country, VTEC has not been routinely investigated in most of the diagnostic microbiology laboratories in Turkey and studies related to this topic are limited. In this study, the incidence of E.coli O157:H7 in patients who were admitted to Alanya Research and Applic ...201121935785
Gut microbiota and pediatric disease.Background: Researchers have made every effort to assess the role of gut microbiota in pediatric diseases like inflammatory bowel disease (IBD), celiac disease, asthma, allergy, and autism. The leading hypothesis is that an altered microbial composition is present (other than the presence of a specific pathogen) and that it could be involved in the pathogenesis or progression of such disorders. Methods: Cultural, molecular, metabolomic, and metagenomic approaches are trying to define the pediatr ...201122179208
molecular characterization of extended-spectrum β-lactamase-producing shigella isolates from humans in south africa, 2003-2009. 201221903820
Detection of diarrhoeal pathogens in human faeces using an automated, robotic platform.Infectious diarrhoeal diseases represent a major socio-economic burden to humans, and are linked to a range of pathogens, including viruses, bacteria and protists. The accurate detection of such pathogens is central to control. However, detection often relies on methods that have limited diagnostic sensitivity and specificity. Here, we assessed an automated, robotic platform for the simultaneous detection of eight major pathogens associated with infectious diarrhoea. Genomic DNA samples (n = 167 ...201122056326
Genotyping of selected bacterial enteropathogens in Norway.In Norway the Norwegian Institute of Public Health (NIPH) is the primary facility for nationwide surveillance of foodborne infections, and it is vital that we can perform rapid and high resolution identification of foodborne bacteria at the strain level. During the last decade a rapid introduction of DNA-based methods has been introduced, which show promise in enhancing the speed and discriminatory capability of the typing laboratory. The laboratory responsible for genotyping enteropathogens at ...201121975141
Third-generation cephalosporin resistance in clinical isolate of Shigella sonnei in Andaman & Nicobar Islands, India. 201121918310
Differential host immune responses to epidemic and endemic strains of Shigella dysenteriae type I.Shigella dysenteriae type 1 causes devastating epidemics in developing countries with high case-fatality rates in all age-groups. The aim of the study was to compare host immune responses to epidemic (T2218) and endemic strains of S. dysenteriae type 1. Shigellacidal activity of serum from rabbits immunized with epidemic or endemic strains, S. dysenteriae type 1-infected patients, and healthy adult controls from Shigella-endemic and non-endemic regions was measured. Immunogenic cross-reactivity ...201122106748
Simultaneous Detection of Six Diarrhea-Causing Bacterial Pathogens with an In-House PCR-Luminex Assay.Diarrhea can be caused by a range of pathogens, including several bacteria. Conventional diagnostic methods, such as culture, biochemical tests, and enzyme-linked immunosorbent assay (ELISA), are laborious. We developed a 7-plex PCR-Luminex assay to simultaneously screen for several of the major diarrhea-causing bacteria directly in fecal specimens, including pathogenic Aeromonas, Campylobacter jejuni, Campylobacter coli, Salmonella, Shigella, enteroinvasive Escherichia coli (EIEC), Vibrio, and ...201222075596
Acid-bile, antibiotic resistance and inhibitory properties of propionibacteria isolated from Turkish traditional home-made cheeses.In this study, a total of 29 Propionibacterium spp. were isolated from traditional home-made Turkish cheese samples. As a result of the identification, isolates were identified as Propionibacterium freudenreichii subsp. freudenreichii (15 strains), Propionibacterium jensenii (12), and Propionibacterium thoenii (2). All isolates and 5 reference strains were examined for their abilities to survive at pH 2.0, 3.0, 4.0, 5.0 and in the presence of 0.06, 0.15 and 0.30% bile salts, their influence on t ...201122019987
Prevalence and antimicrobial susceptibility of major foodborne pathogens in imported seafood.Seafood is a leading commodity implicated in foodborne disease outbreaks in the United States. Seafood importation rose dramatically in the past 3 decades and now contributes to more than 80% of the total U.S. seafood supply. However, limited data are available on the microbiological safety of imported seafood. In this study, we obtained a total of 171 salmon, shrimp, and tilapia samples imported from 12 countries in three retail stores in Baton Rouge, LA. The total microbial population and the ...201121902913
a broadly protective shigella vaccine based on type iii secretion apparatus proteins.shigella ssp. are food and water-borne pathogens that cause severe diarrheal and dysenteric disease associated with high morbidity and mortality. individuals most often affected are children under 5 years of age in the developing world. the existence of multiple shigella serotypes and the heterogenic distribution of pathogenic strains as well as emerging antibiotic resistance require the development of a broadly protective vaccine. all shigella ssp. utilize a type iii secretion system (ttss) to ...201122202122
Nicotinamide dependence of uropathogenic Escherichia coli UTI89 and application of nadB as a neutral insertion site.NAD and NADP function ubiquitously in the metabolism of Escherichia coli K-12. NAD auxotrophy can be rendered by mutation in any of the three genes, nadB, nadA, and nadC. The nadB and nadA genes were defined as anti-virulence loci in Shigella spp., as a mutation (mainly in nadB) disrupting the synthesis of quinolinate is required for virulence. Uropathogenic E. coli (UPEC) isolates, from acute cystitis patients, exhibiting nicotinamide auxotrophy were of serotype O18:K1:H7. E. coli UTI89, the mo ...201122174382
microbial aspects of protein recovery from meat industry by-products.a significant reduction in the number of micro-organisms associated with the bovine meat by-products, lung, rumen and blood plasma, was noted after their alkali-extractable proteins had been spun into a fibrous form. most of the effect was found when the protein was coagulated in a 10% acetic acid/10% sodium chloride bath. whereas the approximate shelf-life of raw rumen and lung was three and four days, respectively (at 0°c), proteins isolated from these tissues were relatively stable and could ...197922055264
recombinant shiga toxin b subunit elicits protection against shiga toxin via mixed th type immune response in mice.shigella dysenteriae is the causative agent of the third commonest bacterial disease for childhood diarrhoea and responsible for millions of deaths per year. it produces potent toxin termed shiga toxin which is listed in category b biological warfare agent of cdc, usa. earlier we have reported production of recombinant shiga toxin b subunit that produced antibodies which neutralized shiga toxin toxicity in hela cells. in the present study, we have evaluated the immunomodulatory potential of rstx ...201121856355
up-regulation of muc2 and il-1β expression in human colonic epithelial cells by shigella and its interaction with mucins.the entire gastrointestinal tract is protected by a mucous layer, which contains complex glycoproteins called mucins. muc2 is one such mucin that protects the colonic mucosa from invading microbes. the initial interaction between microbes and mucins is an important step for microbial pathogenesis. hence, it was of interest to investigate the relationship between host (mucin) and pathogen interaction, including shigella induced expression of muc2 and il-1β during shigellosis.201122073249
shiga toxins: intracellular trafficking to the er leading to activation of host cell stress responses.despite efforts to improve hygenic conditions and regulate food and drinking water safety, the enteric pathogens, shiga toxin-producing escherichia coli (stec) and shigella dysenteriae serotype 1 remain major public health concerns due to widespread outbreaks and the severity of extra-intestinal diseases they cause, including acute renal failure and central nervous system complications. shiga toxins are the key virulence factors expressed by these pathogens mediating extra-intestinal disease. de ...201022069648
a school outbreak of shigella sonnei infection in china: clinical features, antibiotic susceptibility and molecular epidemiology.objective: to describe the clinical features of infection, and the antibiotic susceptibility of epidemic strains, and investigate plasmid maps and integrons of the isolates from an outbreak of shigella sonnei infection at an elementary school in southwest china. study design: cross-sectional study. setting: an elementary school and five hospitals in chengdu in southwest china. results: there were 1,134 students in the school. 937 (82.6%) students had signs and symptoms. of the 568 (60.6%, 568/93 ...201121992857
Evolutionary and functional insights into Leishmania META1: evidence for lateral gene transfer and a role for META1 in secretion.ABSTRACT: BACKGROUND: Leishmania META1 has for long been a candidate molecule for involvement in virulence: META1 transcript and protein are up-regulated in metacyclic Leishmania. Yet, how META1 contributes to virulence remains unclear. We sought insights into the possible functions of META1 by studying its evolutionary origins. RESULTS: Using multiple criteria including sequence similarity, nucleotide composition, phylogenetic analysis and selection pressure on gene sequence, we present evide ...201122093578
[Dysentery and amoebiasis in Poland in 2009].Only 30 cases were notified (incidence rate 0.08/100 000 population) in the year 2009, while the 33 cases were notified in 2008 (incidence rate 0.09/100 000), and median in the 2003-2007 years was 74 cases, incidence rate 0.19/100 000 population. Since 2000 no one-death case was notified. In the period of low frequency of Shigella infections, the external quality assessment control of the quality of bacteriological media, laboratory and prae-laboratory procedures for detection of different Shige ...201121913464
A new piece of the Shigella pathogenicity puzzle: spermidine accumulationby silencing of the speG gene.The genome of Shigella, a gram negative bacterium which is the causative agent of bacillary dysentery, shares strong homologies with that of its commensal ancestor, Escherichia coli. The acquisition, by lateral gene transfer, of a large plasmid carrying virulence determinants has been a crucial event in the evolution towards the pathogenic lifestyle and has been paralleled by the occurrence of mutations affecting genes, which negatively interfere with the expression of virulence factors. In this ...201122102881
topological characterisation and identification of critical domains within glucosyltransferase iv (gtriv) of shigella flexneri.abstract:201122188643
The effects of solid media type on routine identification of bacterial isolates using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry.Background: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis is a rapid method for the identification of bacteria based upon the comparison of protein profiles. Factors that may alter profiles include culture conditions and presence of exogenous substances and could hinder identification. Methods: Bacterial isolates identified using conventional methods were cultured on various media and identified using the MALDI Biotyper system (Bruker Dalton ...201122162546
The scope of phage display for membrane proteins.Numerous examples of phage display applied to soluble proteins demonstrate the power of the technique for protein engineering, affinity reagent discovery and structure-function studies. Recent reports have expanded phage display to include membrane proteins (MPs). The scope and limitations of MP display remain undefined. Therefore, we report data from the phage display of representative types of membrane-associated proteins including plasma, nuclear, peripheral, single and multipass. The periphe ...201122037583
outbreak of shigella sonnei infection in norway linked to consumption of fresh basil, october 2011.we report a shigella sonnei outbreak of 46 cases that occurred in norway during october 2011. two municipalities were involved. a large cluster (42 cases)was concentrated in north norway, while a smallcluster (4 cases) occurred in the south-east region.epidemiological evidence and trace back investigations have linked the outbreak to the consumption of imported fresh basil. the product has been withdrawn from the market. no further cases have been reported since 25 october.201122085618
reflectron maldi tof and maldi tof/tof mass spectrometry reveal novel structural details of native lipooligosaccharides.lipooligosaccharides (los) are powerful gram-negative glycolipids that evade the immune system and invade host animal and vegetal cells. the structural elucidation of los is pivotal to understanding the mechanisms of infection at the molecular level. the amphiphilic nature of los has been the main obstacle for structural analysis by matrix-assisted laser desorption/ionization (maldi) mass spectrometry (ms). our approach has resolved this important issue and has permitted us to obtain reflectron ...201122124985
foodborne-associated shigella sonnei, india, 2009 and 2010. 201122099103
Misidentification of a commensal inactive Escherichia coli as Shigella sonnei by an automated system in a critically ill patient.Though automated identification and sensitivity testing has established itself as a standard in many high throughput clinical microbiology laboratories, misidentification by the automated systems can also happen.201122029193
Rotavirus in adults requiring hospitalization.To determine the prevalence and epidemiological characteristics of rotavirus among adults admitted to the hospital with diarrhea that have bacterial stool cultures sent.201221939687
prevalence and antimicrobial susceptibility patterns of shigella species at felege hiwot referral hospital, northwest ethiopia.shigella species infections coupled with increased levels of antimicrobial resistances are major public health problems in developing countries particularly in children.201121991758
evolutionary silence of the acid chaperone protein hdeb in enterohemorrhagic escherichia coli o157:h7.the periplasmic chaperones hdea and hdeb are known to be important for cell survival at low ph (ph<3) in escherichia coli and shigella spp. here we investigated the roles of hdea and hdeb in the survival of various enterohemorrhagic e. coli (ehec) following exposure to ph 2.0. similar to k-12 strains, the acid protections conferred by hdea and hdeb in ehec o145 were significant: loss of hdea and hdeb led to over 100- to 1000-fold reductions in acid survival, depending on the growth condition of ...201122179243
rational design of an artificial genetic switch: co-option of the h-ns-repressed prou operon by the virb virulence master regulator.the h-ns protein represses the transcription of hundreds of genes in gram-negative bacteria. derepression is achieved by a multitude of mechanisms, many of which involve the binding of a protein to dna at the repressed promoter in a manner that compromises the maintenance of the h-ns-dna nucleoprotein repression complex. the principal virulence gene promoters in shigella flexneri, the cause of bacillary dysentery, are repressed by h-ns. virb, a protein that closely resembles members of the parb ...201121873493
the inhibitory activity of lactobacillus spp. isolated from breast milk on gastrointestinal pathogenic bacteria of nosocomial origin.milk acts as a mean for transporting many essential substances from the mother to the child. in human beings, milk includes several predominant bacteria, such as staphylococci, streptococci, micrococci, lactobacilli, enterococci, lactococci and bifidobacteria. besides, its intake favors the predominance of bifidobacteria and lactobacilli in the child's intestinal microbiota. the present work explores the isolation and selection of lactobacilli strains with probiotic potential, focusing in their ...201121846506
Crystal Structure of the VapBC Toxin-Antitoxin Complex from Shigella flexneri Reveals a Hetero-Octameric DNA-Binding Assembly.Toxin-antitoxin (TA) loci are common in archaea and prokaryotes and allow cells to rapidly adapt to changing environmental conditions through release of active regulators of metabolism. Many toxins are endonucleases that target cellular mRNA and tRNAs, while the antitoxins tightly wrap around the toxins to inhibit them under normal circumstances. The antitoxins also bind to operators in the promoter regions of the cognate TA operon and thereby regulate transcription. For enteric vapBC TA loci, t ...201122037005
applications of pcr (real-time and masstag) and enzyme-linked immunosorbent assay in diagnosis of respiratory infections and diarrheal illness among deployed u.s. military personnel during exercise balikatan 2009, philippines.laboratory-based surveillance for diarrheal and respiratory illness was conducted at the 2009 republic of the philippines-united states balikatan exercise to determine the presence of specific pathogens endemic in the locations where the military exercises were conducted. ten stool and 6 respiratory specimens were obtained from individuals meeting case definitions for diarrhea or respiratory illness. stool specimens were frozen in dry ice and remotely tested using enzyme-linked immunosorbent ass ...201122128641
synthesis and biological evaluation of some thiazolidinones as antimicrobial agents.a novel series of thiazolidinone derivatives namely 4-(4-dimethylamino-6-{4-[5-(4-ethylpiperazin-1-ylmethyl)-4-oxo-2-phenylthiazolidin-3-yl]-phenylamino}-[1,3,5]triazin-2-yloxy)-1-methyl-1h-quinolin-2-one have been synthesized from the key intermediate 4-[4-(4-aminophenylamino)-6-dimethylamino-[1,3,5]triazin-2-yloxy]-1-methyl-1h-quinolin-2-one (7). condensation reaction of compound 7 with different aldehyde derivatives were performed to obtain schiff base derivatives, which after cyclization gav ...201122182927
shiga toxin is transported into the nucleoli of intestinal epithelial cells via a carrier-dependent process.shiga toxin (stx) produced by the invasive shigella dysenteriae serotype 1 (s. dysenteriae1) causes gastrointestinal and kidney complications. it has been assumed that stx is released intracellularly after enterocyte invasion by s. dysenteriae1. however, there is little information about stx distribution inside s. dysenteriae1-infected enterocytes. here, we use intestinal epithelial t84 cells to characterize the trafficking of stx delivered into the cytosol, in ways that mimic aspects of s. dyse ...201022069640
diarrhea associated with shigella in children and susceptibility to antimicrobials.objective: to evaluate the distribution and susceptibility to antimicrobials of shigella isolated from children with acute diarrhea and without diarrhea in teresina, state of piauí, brazil. methods: four hundred children aged up to 60 months were studied. stools were collected from all the patients between january 2004 and august 2007. shigella was identified by conventional methods and antibiogram and extended-spectrum beta-lactamase (esbl) were performed by agar diffusion. results: shigellosis ...201122089139
antimicrobial and toxicological activities of five medicinal plant species from cameroon traditional medicine.infectious diseases caused by multiresistant microbial strains are on the increase. fighting these diseases with natural products may be more efficacious. the aim of this study was to investigate the in vitro antimicrobial activity of methanolic, ethylacetate (etoac) and hexanic fractions of five cameroonian medicinal plants (piptadeniastum africana, cissus aralioides, hileria latifolia, phyllanthus muellerianus and gladiolus gregasius) against 10 pathogenic microorganisms of the urogenital and ...201121867554
antibacterial characteristics and activity of water-soluble chitosan derivatives prepared by the maillard reaction.the antibacterial activity of water-soluble chitosan derivatives prepared by maillard reactions against staphylococcus aureus, listeria monocytogenes, bacillus cereus, escherichia coli, shigella dysenteriae, and salmonella typhimurium was examined. relatively high antibacterial activity against various microorganisms was noted for the chitosan-glucosamine derivative as compared to the acid-soluble chitosan. in addition, it was found that the susceptibility of the test organisms to the water-solu ...201121989311
an inverse and independent association between helicobacter pylori infection and the incidence of shigellosis and other diarrheal diseases.objectives. we examined the association between helicobacter pylori infection and the incidence of diarrheal diseases.methods. in a nested case-control study participants were sampled from cohorts of male israeli soldiers aged 18-21 years, serving in field units and followed up for diarrheal diseases. case patients (n = 177) were subjects who visited the base clinic because diarrhea and were positive for shigella sonnei (n = 66), enterotoxigenic escherichia coli (etec) (n = 31) or negative for b ...201122157171
microbiological quality of drinking water from dispensers in roadside restaurants of bangladesh.the microbiological status of water from dispensers in different roadside restaurants of dhaka city and savar area was analyzed in this study. seven samples from dhaka and 8 samples of savar were checked. the heterotrophic plate count was in a range of 1.0 x 10(3) cfu ml(-1) to 2.0 x 10(4) cfu ml(-1) (from new bottles), 1.0 x 10(3) to 1.5 x 10(4) cfu ml(-1) (after dispensation), and 1.5 x 10(3) cfu ml(-1) to 1.0 x l0(5) cfu ml(-1) (from serving glass). in several of the samples, the heterotrophi ...201121916267
validation of the h2s method to detect bacteria of fecal origin by cultured and molecular methods.using biochemical and molecular methods, this research determined whether or not the h(2)s test did correctly identify sewage-contaminated waters by being the first to use culturing and molecular methods to identify the types and numbers of fecal indicator organisms, pathogens, and other microbes present in sewage samples with positive h(2)s test results. for the culture-based method, samples were analyzed for the presence of fecal bacteria by spread plating the sewage sample onto differential a ...201122038242
toxic megacolon.toxic megacolon represents a dreaded complication of mainly inflammatory or infectious conditions of the colon. it is most commonly associated with inflammatory bowel disease (ibd), i.e., ulcerative colitis or ileocolonic crohn's disease. lately, the epidemiology has shifted toward infectious causes, specifically due to an increase of clostridium difficile-associated colitis possibly due to the extensive (ab)use of broad-spectrum antibiotics. other important infectious etiologies include salmone ...201122009735
salmonella typhimurium-specific bacteriophage φsh19 and the origins of species specificity in the vi01-like phage family.whole genome sequencing of bacteriophages suitable for biocontrol of pathogens in food products is a pre-requisite to any phage-based intervention procedure. trials involving the biosanitization of salmonella typhimurium in the pig production environment identified one such candidate, φsh19.201122047448
the effect of the potential phoq histidine kinase inhibitors on shigella flexneri virulence.phoq/phop is an important two-component system that regulates shigella virulence. we explored whether the phoq/phop system is a promising target for new antibiotics against s. flexneri infection. by using a high-throughput screen and enzymatic activity coupled assay, four compounds were found as potential phoq inhibitors. these compounds not only inhibited the activity of sf-phoqc autophosphorylation but also displayed high binding affinities to the sf-phoqc protein in the surface plasmon resona ...201121853073
crosslinking of (cytosine-5)-dna methyltransferase ssoii and its complexes with specific dna duplexes provides an insight into their structures.(cytosine-5)-dna methyltransferase ssoii (m.ssoii) functions as a methyltransferase and also as a transcription factor. chemical and photochemical crosslinking was used for exploring the structure of m.ssoii-dna complexes and m.ssoii in the absence of dna. photocrosslinking with 4-(n-maleimido)benzophenone demonstrated that in the m.ssoii complex with dna containing the regulatory site, the m.ssoii region responsible for methylation was bound to dna flanking the regulatory site, which contained ...201121888553
real-time multiplex pcr for simultaneous detection of campylobacter jejuni, salmonella, shigella and yersinia species in fecal samples.diarrheal diseases due to notifiable bacterial infections require rapid diagnosis of the causative pathogens. to facilitate detection, a real-time multiplex pcr was developed that identifies common diarrhea-causing bacteria in fecal samples. on the basis of published sequence data, sets of primers and probes were designed that were specific for campylobacter jejuni, salmonella, shigella/enteroinvasive escherichia coli eiec, and yersinia species, suitable for use in a one-tube pcr assay. the assa ...201121855409
global distribution of shigella sonnei clones.to investigate global epidemiology of shigella sonnei, we performed multilocus variable number tandem repeat analysis of 1,672 isolates obtained since 1943 from 50 countries on 5 continents and the pacific region. three major clonal groups were identified; 2 were globally spread. type 18 and its derivatives have circulated worldwide in recent decades.201122000369
intestinal parasitosis and shigellosis among diarrheal patients in gondar teaching hospital, northwest ethiopia.abstract:201122041102
antibacterial and anti-inflammatory activity of traditional chinese herb pairs, angelica sinensis and sophora flavescens.the purpose of the present study was to investigate the antibacterial and anti-inflammatory activity of angelica sinensis extract (ae), sophora flavescens extract (se), and herb pair a. sinensis and s. flavescens extract (hpe). endotoxin-induced uveitis (eiu) was induced in rats by a footpad injection of lipopolysaccharide. the anti-inflammatory potential of ae, se, and hpe in the regulation of nuclear factor kappa b (nf-κb), maleic dialdehyde (mda), polymorphonuclear cells (pmn), interleukin-1β ...201121976127
waterlogsy nmr experiments in conjunction with molecular-dynamics simulations identify immobilized water molecules that bridge peptide mimic mdwnmhaa to anticarbohydrate antibody sya/j6.x-ray crystallographic data of the carbohydrate mimic mdwnmhaa when bound to an anti-shigella flexneri y mab sya/j6 indicate the immobilization of water molecules, that is, the presence of "bound" waters, in the active site. water ligand observed via gradient spectroscopy (waterlogsy) was used in conjunction with saturation transfer difference (std)-nmr spectroscopy to probe the existence of immobilized water molecules in the complex of mdwnmhaa 1 bound to mab sya/j6. molecular dynamics simulati ...201121887835
structural segregation of gut microbiota between colorectal cancer patients and healthy volunteers.despite a long-suspected role in the development of human colorectal cancer (crc), the composition of gut microbiota in crc patients has not been adequately described. in this study, fecal bacterial diversity in crc patients (n=46) and healthy volunteers (n=56) were profiled by 454 pyrosequencing of the v3 region of the 16s ribosomal rna gene. both principal component analysis and unifrac analysis showed structural segregation between the two populations. forty-eight operational taxonomic units ...201121850056
social-economic factors and irrational antibiotic use as reasons for antibiotic resistance of bacteria causing common childhood infections in primary healthcare.the most prevalent childhood bacterial infections in primary healthcare are respiratory, gastrointestinal and urogenital infections. the main aim of this paper was to consider factors (socio-economic factors and irrational antibiotic use) that contribute to the development of bacterial resistance, as well as measures that resulted in a reduction of this problem. computerized search through the medline of published articles on antibiotic resistance from 1996 to 2011 in english or serbian was comp ...201121987082
[etiological surveillance and analysis of infectious diarrhea in beijing in year 2010].to explore the pathogenic form, epidemic features and serotype distribution of the pathogenic bacteria causing infectious diarrhea in beijing.201122177306
matrix-assisted laser desorption ionization-time of flight mass spectrometry for the identification of bacteria and yeasts in a clinical microbiological laboratory: a review.recently, maldi-tof ms devices designed for use in clinical laboratories have been commercially introduced in various large centres worldwide. all published studies conclude that maldi-tof ms can be implemented easily for routine identification of bacteria and yeasts in a clinical microbiological laboratory. although all data show that maldi-tof ms correctly identifies the great majority of isolates processed routinely, it cannot yet identify every such isolate. until today, maldi-tof ms is inap ...201121938981
Atypical Shigella boydii 13 encodes virulence factors seen in attaching and effacing Escherichia coli.Enterohemorrhagic E. coli (EHEC) is a foodborne pathogen that causes watery diarrhea and hemorrhagic colitis. In this study, we identified StcE, a secreted zinc metalloprotease that contributes to intimate adherence of EHEC to host cells, in culture supernatants of atypical Shigella boydii 13 (Shigella B13) strains. Further examination of the Shigella B13 strains revealed that this cluster of pathogens does not invade but forms pedestals on HEp-2 cells similar to EHEC and enteropathogenic E. col ...201122126649
characterization of a vii-like phage specific to escherichia coli o157:h7.phage vb_ecom_cba120 (cba120), isolated against escherichia coli o157:h7 from a cattle feedlot, is morphologically very similar to the classic phage vii of salmonella enterica serovar typhi. until recently, little was known genetically or physiologically about the vii-like phages, and none targeting e. coli have been described in the literature. the genome of cba120 has been fully sequenced and is highly similar to those of both vii and the shigella phage ag3. the core set of structural and repl ...201121899740
Further characterization of Shigella sonnei live vaccine candidates WRSs2 and WRSs3-plasmid composition, invasion assays and Sereny reactions. 201121983066
Reactor performance and bacterial pathogen removal in response to sludge retention time in a mesophilic anaerobic digester treating sewage sludge.The effects of sludge retention time (SRT) on reactor performance and bacterial pathogen removal of sludge mesophilic anaerobic digestion (MAD) were investigated in a continuous stirred tank reactor. The average volatile solids removal remained around 20% and the biogas production rate varied from 100 to 132ml/ld. The MAD process was efficient to remove Salmonella sp. and Escherichia coli with removal efficiencies increased with SRT from 11d, 16d to 25d. However, the Shigella sp. removal was ins ...201122197074
Clinical characteristics and antibiotic resistance of Shigella gastroenteritis in Ankara, Turkey between 2003 and 2009, and comparison with previous reports.The aim of this study was to define the epidemiological, clinical, and antibiotic susceptibility patterns of Shigella gastroenteritis cases occurring during the years 2003-2009 and to compare results with those of the years 1987-2002.201121982814
convergent synthesis of the tetrasaccharide repeating unit of the o-antigen of shigella boydii type 9.a convenient synthesis of the tetrasaccharide repeating unit of the o-antigen of shigella boydii type 9 has been achieved in excellent yield using a [2 + 2] block glycosylation strategy. tempo-mediated selective oxidation of the primary alcohol of the tetrasaccharide derivative 8 to the carboxylic group followed by deprotection of the functional groups furnished target tetrasaccharide 1 as its 4-methoxyphenyl glycoside in high yield.201121977201
synthesis of novel quinoxalinone derivatives by conventional and microwave methods and assessing their biological activity.in this study, twenty-one arylaminoquinoxalinone derivatives were synthesized and their antibacterial activities against staphylococci aureus, pseudomonas aureus, escherichia coli, bacillus subtilis, salmonella typhi, and shigella pneumoniae were evaluated relative to known antibiotics; augmentin, ampicillin, and chloramphenicol. the insecticidal activities of the prepared compounds were also investigated against tribolium castaneum using permethrin as a standard insecticide. the derivatives wer ...201122076760
the role of oxyr and soxrs in oxidative stress survival in shigella flexneri.shigella flexneri, a facultative intracellular pathogen, is exposed to a variety of environments inside and outside of the human host. some of these environments may contain significant oxidative stress. s. flexneri mutants were generated with deletions in the major oxidative stress regulators oxyr and/or soxrs to test their importance in shigella biology. strains that contained a deletion of oxyr had reduced growth and survival during aerobic growth, but not microaerobic growth. the mutants wer ...201122015257
live attenuated shigella dysenteriae type 1 vaccine strains overexpressing shiga toxin b subunit.shigella dysenteriae serotype 1 (s. dysenteriae 1) is unique among the shigella species and serotypes in the expression of shiga toxin which contributes to more severe disease sequelae and the ability to cause explosive outbreaks and pandemics. s. dysenteriae 1 shares characteristics with other shigella species, including the capability of causing clinical illness with a very low inoculum (10 to 100 cfu) and resistance to multiple antibiotics, underscoring the need for efficacious vaccines and t ...201121969003
Comparative evaluation of the antibody in lymphocyte supernatant (ALS) and enzyme-linked immunospot (ELISPOT) assays for measuring mucosal immune responses to Shigella antigens.Accurately assessing mucosal immune responses to candidate vaccines remains a technical challenge. ELISPOT is widely used as a surrogate of mucosal immune response by directly enumerating circulating antibody secreting cells (ASCs), while antibody in lymphocyte supernatant (ALS) titers the total amount of antibody secreted by ASC ex vivo using ELISA. ALS is more practical than ELISPOT because the ASC supernatant is frozen for ELISA that can be conducted at any time, with any antigen, and in any ...201121939714
comparative genomic analysis of bacteriophage ep23 infecting shigella sonnei and escherichia coli.bacteriophage ep23 that infects escherichia coli and shigella sonnei was isolated and characterized. the bacteriophage morphology was similar to members of the family siphoviridae. the 44,077 bp genome was fully sequenced using 454 pyrosequencing. comparative genomic and phylogenetic analyses showed that ep23 was most closely related to phage so-1, which infects sodalis glossinidius and phage ssl-2009a, which infects engineered e. coli. genomic comparison indicated that ep23 and so-1 were very s ...201122203555
analysis of synonymous codon usage in shigella flexneri 2a strain 301 and other shigella and escherichia coli strains.in this study, we analysed synonymous codon usage in shigella flexneri 2a strain 301 (sf301) and performed a comparative analysis of synonymous codon usage patterns in sf301 and other strains of shigella and escherichia coli. although there was a significant variety in codon usage bias among different sf301 genes, there was a slight but observable codon usage bias that could primarily be attributable to mutational pressure and translational selection. in addition, the relative abundance of dinuc ...201122112197
Ciprofloxacin-resistant Shigella sonnei among men who have sex with men, Canada, 2010.In 2010, we observed isolates with matching pulsed-field gel electrophoresis patterns from 13 cases of ciprofloxacin-resistant Shigella sonnei in Montréal. We report on the emergence of this resistance type and a study of resistance mechanisms. The investigation suggested local transmission among men who have sex with men associated with sex venues.201121888811
How We Didn't Clean Up Until We Washed Our Hands: Shigellosis in an Elementary and Middle School in North Texas.Shigella outbreaks often continue for months and are linked frequently to poor hygiene and hand washing. Such outbreaks are found often in day care facilities, but rarely are reported in schools. We present the investigation of an outbreak in autumn 2007 at a building that housed an elementary school and a middle school in separate wings in a small Texas city north of Dallas-Fort Worth.201222189658
systematic review: the use of proton pump inhibitors and increased susceptibility to enteric infection.background: the use of proton pump inhibitors (ppis) is increasing worldwide. suppression of gastric acid alters the susceptibility to enteric bacterial pathogens. aim  this systematic review was undertaken to examine the relationship between ppi use and susceptibility to enteric infections by a specific pathogen based on published literature and to discuss the potential mechanisms of ppi enhanced pathogenesis of enteric infections. methods  pubmed, ovid medline databases were searched. search t ...201121999643
[Antimicrobial resistance profiles of Shigella spp. isolated from feces samples in Hacettepe University Ihsan Dogramaci Children's Hospital between 1999-2010].The symptoms of infections caused by Shigella spp. are diverse and may change from person to person. The choice of antibiotics as well as the prevention of the loss of fluid and electrolytes are important in the clinical recovery. The local resistance rates to antibiotics should be taken into consideration when planning empirical therapy. The aims of this retrospective study were to detect the in vitro antimicrobial susceptibility of 605 Shigella spp. strains isolated from feces samples of child ...201122090291
shigella flexneri infection generates the lipid pi5p to alter endocytosis and prevent termination of egfr signaling.the phosphoinositide metabolic pathway, which regulates cellular processes implicated in survival, motility, and trafficking, is often subverted by bacterial pathogens. shigella flexneri, a bacterium that causes dysentery, injects ipgd, a phosphoinositide phosphatase that generates the lipid phosphatidylinositol 5-phosphate (pi5p), into host cells, thereby activating the phosphoinositide 3-kinase-akt survival pathway. we show that epidermal growth factor receptor (egfr) is required for pi5p-depe ...201121934107
genomic characterization of enteroaggregative escherichia coli from children in mali.background. enteroaggregative escherichia coli (eaec) is a cause of epidemic and sporadic diarrhea, yet its role as an enteric pathogen is not fully understood. methods. we characterized 121 eaec strains isolated in 2008 as part of a case-control study of moderate to severe acute diarrhea among children 0-59 months of age in bamako, mali. we applied multiplex polymerase chain reaction and comparative genome hybridization to identify potential virulence factors among the eaec strains, coupled wit ...201122184729
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