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synthesis, structure and in vitro antibacterial activities of new hybrid disinfectants quaternary ammonium compounds: pyridinium and quinolinium stilbene benzenesulfonates.the series of pyridinium (1-10) and quinolinium (11-20) stilbene benzenesulfonates have been synthesized and their structures were investigated by uv-vis, ft-ir and (1)h nmr spectroscopy. in addition, compound 5 was also determined by single crystal x-ray diffraction technique. the antibacterial activity of the synthesized compounds against both gram-positive and gram-negative bacteria has been determined. the quinolinium derivatives exhibited two very potent characteristic activities, namely, ( ...201020619939
comparison of 61 sequenced escherichia coli genomes.escherichia coli is an important component of the biosphere and is an ideal model for studies of processes involved in bacterial genome evolution. sixty-one publically available e. coli and shigella spp. sequenced genomes are compared, using basic methods to produce phylogenetic and proteomics trees, and to identify the pan- and core genomes of this set of sequenced strains. a hierarchical clustering of variable genes allowed clear separation of the strains into clusters, including known pathoty ...201020623278
reduced azithromycin susceptibility in shigella sonnei, united states.to investigate azithromycin susceptibility in shigella sonnei in the united states, we examined the azithromycin minimum inhibitory concentrations (mics) of outbreak and routine human s. sonnei isolates. isolate susceptibility clustered at 8 mg/l, but three isolates displayed higher mics (>64  mg/l) to azithromycin. all three isolates contained a plasmid-encoded mpha gene, known to encode a macrolide-2'-phosphotransferase enzyme. transformation of the mpha gene into escherichia coli dh10b allowe ...201020624094
evidence for alternative quaternary structure in a bacterial type iii secretion system chaperone.type iii secretion systems are a common virulence mechanism in many gram-negative bacterial pathogens. these systems use a nanomachine resembling a molecular needle and syringe to provide an energized conduit for the translocation of effector proteins from the bacterial cytoplasm to the host cell cytoplasm for the benefit of the pathogen. prior to translocation specialized chaperones maintain proper effector protein conformation. the class ii chaperone, invasion plasmid gene (ipg) c, stabilizes ...201020633281
prolonged episodes of acute diarrhea reduce growth and increase risk of persistent diarrhea in children.prolonged episodes of acute diarrhea (prod; duration 7-13 days) or persistent diarrhea (pd; duration ≥14 days) are important causes of undernutrition, yet the epidemiology and nutritional impact of prod are poorly understood.201020638937
the omptins of yersinia pestis and salmonella enterica cleave the reactive center loop of plasminogen activator inhibitor 1.plasminogen activator inhibitor 1 (pai-1) is a serine protease inhibitor (serpin) and a key molecule that regulates fibrinolysis by inactivating human plasminogen activators. here we show that two important human pathogens, the plague bacterium yersinia pestis and the enteropathogen salmonella enterica serovar typhimurium, inactivate pai-1 by cleaving the r346-m347 bait peptide bond in the reactive center loop. no cleavage of pai-1 was detected with yersinia pseudotuberculosis, an oral/fecal pat ...201020639337
shiga toxin b subunits induce vwf secretion by human endothelial cells and thrombotic microangiopathy in adamts13-deficient mice.diarrhea-associated hemolytic uremic syndrome (d+hus) is the most common cause of acute renal failure among children. renal damage in d+hus is caused by shiga toxin (stx), which is elaborated by shigella dysenteriae and certain strains of escherichia coli, in north america principally e coli o157:h7. recent studies demonstrate that stx also induces von willebrand factor (vwf) secretion by human endothelial cells and causes thrombotic thrombocytopenic purpura, a disease with similarities to d+hus ...201020644116
photodynamic antimicrobial chemotherapy by liposome-encapsulated water-soluble photosensitizers.photodynamic antimicrobial chemotherapy is an alternative method for killing bacterial cells in view of the increasing problem of multi-antibiotic resistance. we examined the effect of three water-soluble photosensitizers (phs): methylene blue (mb), neutral red (nr) and rose bengal (rb) on gram-positive and gram-negative bacteria. we compared the efficacy of phs in their free form and encapsulated in liposomal formulations against various bacterial strains, and determined conditions for the effe ...201020644595
[structure of the oligosaccharide region (core) of the lipopolysaccharides of shigella flexneri types 2a and 5b].the full structure of the lipopolysaccharide core of bacteria shigella flexneri types 2a and 5b, the causative agents of bacillary dysentery (shigellosis), was established by chemical methods, high-resolution electrospray ionization mass spectrometry, and two-dimensional nmr spectroscopy. the structure of the o-antigen repeating unit and the configuration and position of the linkage between the o-antigen and the core were determined in the lipopolysaccharide of s. flexneri type 2a.201020644600
antibacterial properties of essential oils and methanol extracts of sweet basil ocimum basilicum occurring in bangladesh.the antibacterial potential of essential oils and methanol extracts of sweet basil ocimum basilicum l. (lamiaceae) was evaluated for controlling the growth range of food-borne pathogenic bacteria. essential oils extracted by hydrodistillation from the leaves and stems were analyzed by gc-ms. fifty-seven compounds representing 94.9 and 96.1% of the total leaf and stem oils, respectively, were identified, of which methyl chavicol (36.7 and 29.9%), gitoxigenin (9.3 and 10.2%), trimethoquinol (10.3 ...201020645791
enteropathogenic escherichia coli, samonella, shigella and yersinia: cellular aspects of host-bacteria interactions in enteric diseases.abstract: a successful infection of the human intestine by enteropathogenic bacteria depends on the ability of bacteria to attach and colonize the intestinal epithelium and, in some cases, to invade the host cell, survive intracellularly and disseminate from cell to cell. to accomplish these processes bacteria have evolved an arsenal of molecules that are mostly secreted by dedicated type iii secretion systems, and that interact with the host, subverting normal cellular functions. here we overvi ...201020649986
in silico characterization of shikimate kinase of shigella flexneri: a potential drug target.shigella flexneri is a major pathogen responsible for shigellosis causing massive morbidity among young population and imposes huge socio-economic burden. in this study, shikimate kinase (sk) from s. flexneri was characterized in silico and disordered regions were predicted. motifs and domains were calculated using computational tools. a three dimensional model of shikimate kinase of s.flexneri was constructed using shikimate kinase of e.coli (pdbid: 1kag_a) as template by comparative modeling a ...201020658341
convalescent cultures for control of shigellosis outbreaks.a shigellosis outbreak in the st louis, missouri metropolitan area.201020661101
prevalence of integrons in shigella sonnei from brazil. 201020664608
synthesis and in vitro antibacterial activity of novel fluoroquinolone derivatives containing substituted piperidines.we report herein the synthesis of novel 7-(4-alkoxyimino-3-aminomethyl-3-methylpiperidin-1-yl) fluoroquinolone derivatives. the antibacterial activity of the newly synthesized compounds was evaluated and correlated with their physicochemical properties. results reveal that all of the target compounds have good potency in inhibiting the growth of staphylococcus aureus and staphylococcus epidermidis including mrse (mic: 0.125-4 microg/ml). compounds 12, 13 are more potent than or comparable to lev ...201020667731
glycan encapsulated gold nanoparticles selectively inhibit shiga toxins 1 and 2.shiga toxins (stx) released by escherichia coli o157:h7 and shigella dysentriae cause life-threatening conditions that include hemolytic uremic syndrome (hus), kidney failure, and neurological complications. cellular entry is mediated by the b-subunit of the ab(5) toxin, which recognizes cell surface glycolipids present in lipid raft-like structures. we developed gold glyconanoparticles that present a multivalent display similar to the cell surface glycolipids to compete for these toxins. these ...201020669970
control of coliform bacteria detected from diarrhea associated patients by extracts of moringa oleifera.the aims of this study were to determine the total population of coliform bacteria in the samples collected from diarrhea associated patients from the local area of bangladesh and to examine the antibacterial efficacy of leaf extracts of moringa oleifera (moringaceae) against the isolated coliform bacteria. the coliform bacteria detected in these samples by some microbial-biochemical tests such as escherichia coli, shigella dysenteriae, salmonella sp., enterobacter sp., klebsiella pneumoniae and ...201020677603
impact of diet in shaping gut microbiota revealed by a comparative study in children from europe and rural africa.gut microbial composition depends on different dietary habits just as health depends on microbial metabolism, but the association of microbiota with different diets in human populations has not yet been shown. in this work, we compared the fecal microbiota of european children (eu) and that of children from a rural african village of burkina faso (bf), where the diet, high in fiber content, is similar to that of early human settlements at the time of the birth of agriculture. by using high-throu ...201020679230
facile glycosylation strategy with two-stage activation of allyl glycosyl donors. application to concise synthesis of shigella flexneri serotype y o-antigen.a practical, useful glycosylation method employing only allyl glycoside building blocks has been developed. the donor's glycosylation reactivity is turned on via isomerization of its anomeric allyl protecting group into the corresponding prop-1-enyl moiety. subsequent chemoselective activation with nis/tfoh achieves high yields in glycosidic bond construction at room temperature. the efficacy and efficiency of this approach in carbohydrate synthesis is demonstrated in the concise synthesis of th ...201020683518
antimicrobial resistance and molecular analysis of non-typhoidal salmonella isolates from human in tunisia.during the period from 2006 to 2007, a total of 32 clinical isolates of salmonella enterica were isolated from diarrheagenic stool samples and further examined for their susceptibility to various antibiotics. sixteen of the human isolates were from the capital tunis, 11 were from sousse, four were from nabeul and one was from mahdia, tunisia. the isolates were serotyped and identified at the national centre of enteropathogenic bacteria, pasteur institute, tunis (centre national de salmonella, sh ...201020685046
plasmid-mediated streptomycin and sulfamethoxazole resistance in shigella flexneri 3a.shigellosis is a major cause of diarrhoea-related morbidity and mortality, especially in children in developing countries such as india. recently, it was estimated that 91 million individuals worldwide contract shigellosis each year. the emergence and dissemination of multidrug-resistant strains of shigella is now an emerging global health problem. during the past two decades, much attention was given to re-evaluation of treatment recommendations. in the present study, we investigated a clinical ...201020685089
antibiotic therapy for shigella dysentery.shigella dysentery is a relatively common illness and occasionally causes death, worldwide. mild symptoms are self-limiting but in more severe cases, antibiotics are recommended for cure and preventing relapse. the antibiotics recommended are diverse, have regional differences in sensitivity, and have side effects.201020687081
hemolysin e (hlye, clya, shea) and related toxins.certain strains of escherichia coli, salmonella enterica and shigella flexneri produce a pore-forming toxin hemolysin e (hlye), also known as cytolysin a (clya) and silent hemolysin, locus a (shea). hlye lyses erythrocytes and mammalian cells, forming transmembrane pores with a minimum internal diameter of-25 a. we review the current knowledge of hlye structure and function in its solution and pore forms, models for membrane insertion, its potential use in biotechnology applications and its rela ...201020687485
shigellosis update: advancing antibiotic resistance, investment empowered vaccine development, and green bananas.shigella is the principal cause of clinical dysentery and an important cause of morbidity and mortality among children in impoverished regions. the purpose of this review is to present key findings in the areas of epidemiology, disease control, and treatment of shigellosis.201020689423
etiology of diarrhea in older children, adolescents and adults: a systematic review.diarrhea is an important cause of morbidity and mortality in all regions of the world and among all ages, yet little is known about the fraction of diarrhea episodes and deaths due to each pathogen.201020689809
crystal structures of phd-doc, higa, and yeeu establish multiple evolutionary links between microbial growth-regulating toxin-antitoxin systems.bacterial toxin-antitoxin (ta) systems serve a variety of physiological functions including regulation of cell growth and maintenance of foreign genetic elements. sequence analyses suggest that ta families are linked by complex evolutionary relationships reflecting likely swapping of functional domains between different ta families. our crystal structures of phd-doc from bacteriophage p1, the higa antitoxin from escherichia coli cft073, and yeeu of the yeeuwv systems from e. coli k12 and shigell ...201020696400
pic, an autotransporter protein secreted by different pathogens in the enterobacteriaceae family, is a potent mucus secretagogue.a hallmark of enteroaggregative escherichia coli (eaec) infection is a formation of biofilm, which comprises a mucus layer with immersed bacteria in the intestines of patients. while studying the mucinolytic activity of pic in an in vivo system, rat ileal loops, we surprisingly found that eaec induced hypersecretion of mucus, which was accompanied by an increase in the number of mucus-containing goblet cells. interestingly, an isogenic pic mutant (eaec δpic) was unable to cause this mucus hypers ...201020696826
diverse pathways for salicin utilization in shigella sonnei and escherichia coli carrying an impaired bgl operon.utilization of the aryl-β-glucosides salicin or arbutin in most wild-type strains of e. coli is achieved by a single-step mutational activation of the bgl operon. shigella sonnei, a branch of the diverse e. coli strain tree, requires two sequential mutational steps for achieving salicin utilization as the bglb gene, encoding the phospho-β-glucosidase b, harbors an inactivating insertion. we show that in a natural isolate of s. sonnei, transcriptional activation of the gene sso1595, encoding a ph ...201020697693
[mucocutaneous abnormalities in chlamydia trachomatis-induced reactive arthritis].reactive arthritis (previously known as reiters syndrome) is an inflammatory arthritis that is a type of spondyloarthropathy. the disease consists of the classical triad of arthritis, urethritis and conjunctivitis, but mucocutaneous abnormalities also frequently appear: balanitis circinata, keratoderma blennorrhagicum, aphthous ulcers in the mouth and nail disorders. these skin lesions are mainly found in reactive arthritis induced by chlamydia trachomatis (ct). reactive arthritis is often trigg ...201020699017
production of glycoprotein vaccines in escherichia coli.conjugate vaccines in which polysaccharide antigens are covalently linked to carrier proteins belong to the most effective and safest vaccines against bacterial pathogens. state-of-the art production of conjugate vaccines using chemical methods is a laborious, multi-step process. in vivo enzymatic coupling using the general glycosylation pathway of campylobacter jejuni in recombinant escherichia coli has been suggested as a simpler method for producing conjugate vaccines. in this study we descri ...201020701771
comparative in vitro activity of tigecycline and other antimicrobial agents against shigella species from kuwait and the united arab of emirates.shigella species isolated from stool samples of symptomatic patients of all age groups at the mubarak al kabir hospital and infectious diseases hospital, kuwait and tawam hospital, uae during a 2-year period were investigated for their susceptibility to tigecycline and several other antibiotics by determining the minimum inhibitory concentrations (mics) using the e test method. a total of 100 and 42 strains were collected from uae and kuwait, respectively. the extent of drug resistance in the sh ...201020701889
foodborne proportion of gastrointestinal illness: estimates from a canadian expert elicitation survey.the study used a structured expert elicitation survey to derive estimates of the foodborne attributable proportion for nine illnesses caused by enteric pathogens in canada. it was based on a similar study conducted in the united states and focused on campylobacter, escherichia coli o157:h7, listeria monocytogenes, nontyphoidal salmonella enterica, shigella spp., vibrio spp., yersinia enterocolitica, cryptosporidium parvum, and norwalk-like virus. for each pathogen, experts were asked to provide ...201020704505
seasonal variation of enteropathogens in infants and preschoolers with acute diarrhea in western mexico.the present study estimates the prevalence of some enteropathogens in infants and preschoolers with acute diarrhea. from 2006 to 2007, 5459 consecutive stool samples were evaluated. cryptosporidium parvum was the parasite identified with the higher frequency (5.1%), followed by giardia lamblia (1.2%). campylobacter jejuni was isolated in 858 cases (15.7%) and was the most frequent enteropathogen overall. the rates of c parvum, shigella, and salmonella were higher in the summer. rotavirus had the ...201020706147
csra and cra influence shigella flexneri pathogenesis.shigella flexneri is a facultative intracellular pathogen that invades and disrupts the colonic epithelium. in order to thrive in the host, s. flexneri must adapt to environmental conditions in the gut and within the eukaryotic cytosol, including variability in the available carbon sources and other nutrients. we examined the roles of the carbon consumption regulators csra and cra in a cell culture model of s. flexneri virulence. csra is an activator of glycolysis and a repressor of gluconeogene ...201020713625
structure of shigella ipgb2 in complex with human rhoa: implications for the mechanism of bacterial guanine nucleotide exchange factor mimicry.a common theme in bacterial pathogenesis is the manipulation of eukaryotic cells by targeting the cytoskeleton. this is in most cases achieved either by modifying actin, or indirectly via activation of key regulators controlling actin dynamics such as rho-gtpases. a novel group of bacterial virulence factors termed the wxxxe family has emerged as guanine nucleotide exchange factors (gefs) for these gtpases. the precise mechanism of nucleotide exchange, however, has remained unclear. here we repo ...201020363740
isolation of bacteria from mouse caecal samples and description of bacteroides sartorii sp. nov.caecal samples from wild-type and tnf(deltaare) mice were cultured on selective media containing bile salts, amino acids or casein macro-peptides. twenty-two strains were isolated and identified by 16s rrna gene sequencing. twenty-one strains showed >98% similarity to known bacteria (blautia spp., clostridium innocuum, enterococcus spp., escherichia coli, lactobacillus murinus, parabacteroides goldsteinii and shigella dysenteriae). one additional isolate, strain a-c2-0, was a new bacterium. the ...201020369227
antibacterial effect of the bioactive compound beauvericin produced by fusarium proliferatum on solid medium of wheat.to obtain the bioactive compound beauvericin (bea), fusarium proliferatum cect 20569 was grown on a solid medium of wheat, utilizing the technique of the solid state fermentation (ssf), being this mycotoxin purified by high performance liquid chromatography (hplc) with a reverse phase semi-preparative column using as the mobile phase acetonitrile/water in gradient condition. the purity of the bea was verified by analytical hplc and liquid chromatography tandem mass spectrometry (lc/ms-ms). the p ...201020371252
the effects of a vegetable-derived probiotic lactic acid bacterium on the immune response.the objective of this study was to investigate the probiotic properties of the fermented vegetable derived lactic acid bacterium, l. plantarum. l. plantarum 10hk2 showed antibacterial activity against pathogenic bacteria and immunomodulating effects on murine macrophage cell lines. raw 264.7 cells stimulated with viable cells of this probiotic strain increased the amounts of pro-inflammatory mediators such as il-1beta, il-6 and tnf-alpha, as well as the anti-inflammatory mediator, il-10. icr mic ...201020377751
use of optical mapping to sort uropathogenic escherichia coli strains into distinct subgroups.optical maps were generated for 33 uropathogenic escherichia coli (upec) isolates. for individual genomes, the ncoi restriction fragments aligned into a unique chromosome map for each individual isolate, which was then compared with the in silico restriction maps of all of the sequenced e. coli and shigella strains. all of the upec isolates clustered separately from the shigella strains as well as the laboratory and enterohaemorrhagic e. coli strains. moreover, the individual strains appeared to ...201020378655
biological potentials and cytotoxicity of various extracts from endemic origanum minutiflorum o. schwarz & p.h. davis.the aim of the present study was to investigate antioxidative, antimicrobial and cytotoxic effects of endemic origanum minutiflorum (o. schwarz & p.h. davis). antioxidant activities of the extracts from o. minutiflorum were evaluated by using dpph radical scavenging, beta-carotene bleaching and metal chelating activity assays. in addition, the amounts of total phenol components in the plant extracts were determined. in the beta-carotene bleaching test, the extracts exhibited in the range of 58.1 ...201020381570
isolation and selection of coliphages as potential biocontrol agents of enterohemorrhagic and shiga toxin-producing e. coli (ehec and stec) in cattle.to isolate, characterize and select phages as potential biocontrol agents of enterohemorrhagic and shiga toxin-producing escherichia coli (ehec and stec) in cattle.201020353429
molecular architecture of the mn2+-dependent lactonase ulag reveals an rnase-like metallo-beta-lactamase fold and a novel quaternary structure.the ulag gene, located in the ula regulon, is crucial for the catabolism of l-ascorbate under anaerobic conditions and it has been proposed to encode for the putative l-ascorbate-6-p lactonase. the ulag gene is widespread among eubacteria, including human commensal and pathogenic genera such as escherichia, shigella, klebsiella and salmonella. here, we report the three-dimensional structures of the apoenzyme and mn(2+) holoenzyme of ulag from e. coli to 2.6 a resolution, determined using single- ...201020359483
modeling fimbriae mediated parasite-host interactions.type 1 fimbriae are a known virulence factor in a number of pathogenic enterobacteriaceae, including salmonella, shigella and e. coli. yet, they are also expressed by some commensal strains, notably of e. coli. one hypothesis of the role of fimbriae in commensals is that they evoke a small but tolerable host immune response in order to have the host release sialic acid, which is a valuable nutrient. genetic evidence suggests that sialic acid down-regulates fimbriation. this has been believed to ...201020359486
microarray analysis of shigella flexneri-infected epithelial cells identifies host factors important for apoptosis inhibition.shigella flexneri inhibits apoptosis in infected epithelial cells. in order to understand the pro-survival effects induced by the bacteria, we utilized apoptosis-specific microarrays to analyze the changes in eukaryotic gene expression in both infected and uninfected cells in the presence and absence of staurosporine, a chemical inducer of the intrinsic pathway of apoptosis. the goal of this research was to identify host factors that contribute to apoptosis inhibition in infected cells.201020429941
bacteriological and parasitological assessment of food handlers in the omdurman area of sudan.pathogenic organisms are thought to be widely distributed among food handlers. this study was designed to assess the prevalence of carriers of some pathogenic bacteria and intestinal parasites among food handlers in the city of omdurman, sudan.201020434126
a multiplex pcr method to detect 14 escherichia coli serogroups associated with urinary tract infections.urinary tract infections (utis) are one of the most common bacterial infections and are predominantly caused by uropathogenic escherichia coli (upec). e. coli strains belonging to 14 serogroups, including o1, o2, o4, o6, o7, o8, o15, o16, o18, o21, o22, o25, o75 and o83, are the most frequently detected upec strains in a diverse range of clinical urine specimens. in the current study, the o-antigen gene clusters of e. coli serogroups o1, o2, o18 and o75 were characterized. a multiplex pcr method ...201020434495
modulation of shigella virulence in response to available oxygen in vivo.bacteria coordinate expression of virulence determinants in response to localized microenvironments in their hosts. here we show that shigella flexneri, which causes dysentery, encounters varying oxygen concentrations in the gastrointestinal tract, which govern activity of its type three secretion system (t3ss). the t3ss is essential for cell invasion and virulence. in anaerobic environments (for example, the gastrointestinal tract lumen), shigella is primed for invasion and expresses extended t ...201020436458
microbial community on healthy and diseased leaves of an invasive plant eupatorium adenophorum in southwest china.invasive plants have caused great economic losses and environmental problems worldwide. eupatorium adenophorum is one of the most invasive weeds in china. to better understand its invasive mechanisms, in the present paper, the microbial communities of healthy and diseased leaves of e. adenophorum were obtained using both culture-independent and -dependent methods and their diversities were compared. the bacteria obtained from culture-independent method belong to proteobacteria (95.8%), actinobac ...201020437143
phenotypic characterization and genomic analysis of the shigella sonnei bacteriophage sp18.a novel bacteriophage that infects shigella sonnei was isolated from the gap river in korea, and its phenotypic and genomic characteristics were investigated. the virus, called sp18, showed morphology characteristic of the family myoviridae, and phylogenetic analysis of major capsid gene (gp23) sequences classified it as a t4-like phage. based on host spectrum analysis, it is lytic to s. sonnei, but not to shigella flexneri, shigella boydii or members of the genera escherichia and salmonella. py ...201020437154
antimicrobial resistance patterns and characterization of integrons of shigella sonnei isolates in seoul, 1999-2008.a total of 66 shigella sonnei isolates from 1999 to 2008 in seoul was analyzed for their antimicrobial resistance, carriage of integron, and the patterns of pulsed-field gel electrophoresis (pfge). a high level of antimicrobial resistance to streptomycin (100%), trimethoprim/sulfamethoxazole (95%), tetracycline (94%), nalidixic acid (65%), and ampicillin (41%) was observed among s. sonnei isolates. fourteen profiles of antimicrobial resistance were identified with the most common resistance prof ...201020437157
antimicrobial resistance trends of shigella serotypes in new york city, 2006-2009.shigellosis is the third most common enteric bacterial infection in the united states. although infection is typically self-limiting, empiric treatment is often prescribed. because of increasing antimicrobial resistance to shigella, empiric treatment options are decreasing. identifying resistance patterns can inform empiric treatment recommendations. the goals of our study were to examine risk factors associated with antimicrobial resistance of shigella and examine issues related to empiric trea ...201020438349
high prevalence of trimethoprim-resistance cassettes in class 1 and 2 integrons in senegalese shigella spp isolates.integrons have a well-established role in the dissemination of resistance among gram-negative pathogens and are thus a useful marker of antibiotic resistance. shigellae are noteworthy for their multiple drug resistance, having gradually acquired resistance to most widely use and inexpensive antimicrobial drugs.201020440057
genome-wide analysis of the h-ns and sfh regulatory networks in salmonella typhimurium identifies a plasmid-encoded transcription silencing mechanism.the conjugative inchi1 plasmid psfr27 from shigella flexneri 2a strain 2457t encodes the sfh protein, a paralogue of the global transcriptional repressor h-ns. sfh allows psfr27 to be transmitted to new bacterial hosts with minimal impact on host fitness, providing a 'stealth' function whose molecular mechanism has yet to be determined. the impact of the sfh protein on the salmonella enterica serovar typhimurium transcriptome was assessed and binding sites for sfh in the salmonella typhimurium g ...201020444106
the role of sura factor in outer membrane protein transport and virulence.the escherichia coli periplasmic chaperone and peptidyl-prolyl isomerase (ppiase) sura is a major factor in the biogenesis of β-barrel outer membrane proteins (omps) and as such plays an integral role in cell envelope homeostasis and cell envelope functions. recently, the biological importance of sura was further substantiated by the finding that sura also affects pathogenicity, being required for full virulence of uropathogenic escherichia coli, salmonella, and shigella spp. moreover, given the ...201020447864
the type iii effectors nlee and nleb from enteropathogenic e. coli and ospz from shigella block nuclear translocation of nf-kappab p65.many bacterial pathogens utilize a type iii secretion system to deliver multiple effector proteins into host cells. here we found that the type iii effectors, nlee from enteropathogenic e. coli (epec) and ospz from shigella, blocked translocation of the p65 subunit of the transcription factor, nf-kappab, to the host cell nucleus. nf-kappab inhibition by nlee was associated with decreased il-8 expression in epec-infected intestinal epithelial cells. ectopically expressed nlee also blocked nuclear ...201020485572
[traveler's diarrhea, the most common health problem of travelers].bacteria cause 50 to 80% of travelers' diarrheic diseases. the most important pathogens include enterotoxigenic escherichia coli (etec), campylobacteria, salmonellae and shigella. diarrheic viruses cause 5 to 25% and protozoa less than 10% of travelers' diarrheas. hand and food hygiene constitute the main preventive measures. treatment of traveler's diarrhea is based on rehydration therapy and rest. antimicrobial therapy is required only in cases with exceptionally severe symptoms.201020486490
violations identified from routine swimming pool inspections--selected states and counties, united states, 2008.swimming is the third most popular u.s. sport or exercise activity, with approximately 314 million visits to recreational water venues, including treated venues (e.g., pools), each year. the most frequently reported type of recreational water illness (rwi) outbreak is gastroenteritis, the incidence of which is increasing. during 1997--2006, chlorine- and bromine-susceptible pathogens (e.g., shigella and norovirus) caused 24 (23%) of 104 treated venue--associated rwi outbreaks of gastroenteritis, ...201020489681
battle and balance at mucosal surfaces--the story of shigella and antimicrobial peptides.shigella is a major cause of morbidity and mortality for children in many developing countries. emergence of antibiotic-resistance among shigella demands the development of effective medicines. antimicrobial peptides (amps) are expressed in phagocytes and at epithelial surfaces and are important effector molecules of innate immunity. we have found that pathogens are able to turn off the endogenous expression of amps, resulting in serious infections such as shigellosis. a therapeutic rationale to ...201020494122
regulation of high-affinity iron acquisition homologues in the tsetse fly symbiont sodalis glossinidius.sodalis glossinidius is a facultative intracellular bacterium that is a secondary symbiont of the tsetse fly (diptera: glossinidae). since studies with other facultative intracellular bacteria have shown that high-affinity iron acquisition genes are upregulated in vivo, we investigated the regulation of several sodalis genes that encode putative iron acquisition systems. these genes, sg1538 (hemt) and sg1516 (sita), are homologous to genes encoding periplasmic heme and iron/manganese transporter ...201020494987
antiviral and anti-inflammatory diterpenoids from the soft coral sinularia gyrosa.chemical investigation of the soft coral sinularia gyrosa led to the purification of three new diterpenoids, designated as gyrosanols a-c (1-3). the structures of 1-3 were elucidated through extensive spectroscopic analyses. compounds 1 and 2 exhibited antiviral activity against hcmv with ic(50)'s of 2.6 and 3.7 microm, respectively. in addition, compounds 1 and 2 showed significant anti-inflammatory activity by reducing the levels of the cox-2 protein (19.6 + or - 3.9% and 29.1 + or - 9.6%, res ...201020499851
foodborne illness: is it on the rise?foodborne illness is a serious public health threat. the centers for disease control and prevention (cdc) estimates that 76 million foodborne illnesses, including 325,000 hospitalizations and 5,000 deaths, occur in the united states each year. two recently published foodborne diseases active surveillance network (foodnet) reports showed that salmonella, campylobacter, shigella, cryptosporidium, and shiga toxin escherichia coli (stec) o157 continue to be leading causes of both the number and inci ...201020500787
[antibacterial activity of recombinant thanatin expressed by e.coli er2566].to express antibacterial peptide thanatin in the prokaryotic expression system and test its antibacterial activity.201020501392
the 33 carboxyl-terminal residues of spa40 orchestrate the multi-step assembly process of the type iii secretion needle complex in shigella flexneri.the type iii secretion apparatus (t3sa) is a central virulence factor of many gram-negative bacteria. its overall morphology consists of a cytoplasmic region, inner- and outer-membrane sections and an extracellular needle. in shigella, the length of the needle is regulated by spa32. to understand better the role of spa32 we searched for its interacting partners using a two-hybrid screen in yeast. we found that spa32 interacts with the 33 c-terminal residues (cc*) of spa40, a member of the conser ...201020507885
induction of specific cd8 t cells against intracellular bacteria by cd8 t-cell-oriented immunization approaches.for protection against intracellular bacteria such as mycobacterium tuberculosis and listeria monocytogenes, the cellular arm of adaptive immunity is necessary. a variety of immunization methods have been evaluated and are reported to induce specific cd8(+) t cells against intracellular bacterial infection. modified bcg vaccines have been examined to enhance cd8(+) t-cell responses. naked dna vaccination is a promising strategy to induce cd8(+) t cells. in addition to this strategy, live attenua ...201020508818
[analysis on bacillary dysentery surveillance data collected from the national surveillance system in 2007.].to improve the national surveillance plan on bacillary dysentery and to increase the sensitivity of the surveillance system on the disease.201020510059
["autophagy and microorganisms": hotspots of a mini-symposium]. 201020510155
establishment of specific pathogen-free macaque colonies in tsukuba primate research center of japan for aids research.cynomolgus monkeys have been maintained in indoor facilities as closed colony monkeys in tsukuba primate research center in japan since 1978. several microorganisms, including bacteria, parasites and viruses, were eliminated from the cynomolgus monkeys in this colony of tprc. various kinds of viruses (b virus, measles virus, simian varicella virus, simian immunodeficiency virus, simian t cell leukemia virus, simian d type retrovirus, simian cytomegalovirus, simian epstein-barr virus, and simian ...201020510748
isolation of bacteriocin-like substances producing bacteria from finished cattle-manure compost and activity evaluation against some food-borne pathogenic and spoilage bacteria.a finished compost sample was examined for bacteriocin-like substance production against five pathogenic bacteria: salmonella typhimurium ef 85-9, escherichia coli o157:h7 atcc 43888, enterococcus faecalis jcm 8726, staphylococcus aureus jcm 2151, and yersinia enterocolitica jcm 7577. at the preliminary detection of bacterial strains exhibiting antimicrobial activity from the compost sample, thirteen strains could be isolated. screening of the inhibitory activity was done using agar-well diffusi ...201020513963
emergence of fluoroquinolone resistance in shigella isolated from andaman & nicobar islands, india. 201020516546
crystallization and preliminary crystallographic studies of corc, a magnesium-ion transporter.corc is a magnesium transporter that is involved in the mg(2+)-efflux function of the cora transporter system, an mg(2+) channel, from shigella flexneri. native corc was purified and crystallized in the native form and in a ligand-free form and diffraction data sets were collected to 2.9 and 3.4 a resolution, respectively. the native corc crystals belonged to space group p2(1)2(1)2(1), with unit-cell parameters a = 64.31, b = 74.44, c = 132.78 a. the ligand-free corc crystals belonged to space g ...201020516599
three-hour molecular detection of campylobacter, salmonella, yersinia, and shigella species in feces with accuracy as high as that of culture.campylobacter jejuni and salmonella, shigella, and yersinia species (along with shiga toxin-producing escherichia coli) are the most common causes of acute bacterial diarrheal disease in the united states. current detection techniques are time-consuming, limiting usefulness for patient care. we developed and validated a panel of rapid pcr assays for the detection and identification of c. jejuni, c. coli, salmonella, and yersinia species and shigella and enteroinvasive e. coli in stool samples. a ...201020519461
emerging trends in the etiology of enteric pathogens as evidenced from an active surveillance of hospitalized diarrhoeal patients in kolkata, india.abstract:201020525383
frequency of viral, bacterial and parasitic enteropathogens among young children with acute diarrhoea in saudi arabia.the frequency of viral, bacterial and parasitic enteropathogens among 270 paediatric patients (< 5 years of age) in various hospitals of makkah and jeddah cities of saudi arabia were investigated.201020527643
prevalence of enterotoxins among escherichia coli isolates causing bacteraemia.the most frequent cause of bacteraemia among gram-negative bacteria is escherichia coli. analysis of the genes encoding the shigella enterotoxin 1 (shet-1), shet-2, enteroaggregative heat stable toxin 1 (east-1) toxins and aggr factor in e. coli strains causing bacteraemia revealed that set1 genes were presented significantly more frequently among quinolone-susceptible strains (p<0.0001), in phylogenetic group b2 (p=0.0004) and in biofilm strains (p=0.02). in contrast, sen genes were significant ...201020529132
a novel anti-virulence gene revealed by proteomic analysis in shigella flexneri 2a.abstract:201020540790
immunochemical studies of shigella flexneri 2a and 6, and shigella dysenteriae type 1 o-specific polysaccharide-core fragments and their protein conjugates as vaccine candidates.there is no licensed vaccine for the prevention of shigellosis. our approach to the development of a shigella vaccines is based on inducing serum igg antibodies to the o-specific polysaccharide (o-sp) domain of their lipopolysaccharides (lps). we have shown that low molecular mass o-sp-core (o-spc) fragments isolated from shigella sonnei lps conjugated to proteins induced significantly higher antibody levels in mice than the full length o-sp conjugates. this finding is now extended to the o-spc ...201020542498
protein refolding is required for assembly of the type three secretion needle.pathogenic gram-negative bacteria use a type three secretion system (ttss) to deliver virulence factors into host cells. although the order in which proteins incorporate into the growing ttss is well described, the underlying assembly mechanisms are still unclear. here we show that the ttss needle protomer refolds spontaneously to extend the needle from the distal end. we developed a functional mutant of the needle protomer from shigella flexneri and salmonella typhimurium to study its assembly ...201020543831
an epidemiologic review of enteropathogens in gaborone, botswana: shifting patterns of resistance in an hiv endemic region.the epidemiology of diarrheal disease in botswana, an hiv endemic region, is largely unknown. our primary objective was to characterize the prevalent bacterial and parasitic enteropathogens in gaborone, botswana. secondary objectives included determining corresponding antimicrobial resistance patterns and the value of stool white and red blood cells for predicting bacterial and parasitic enteropathogens.201020543877
the sudden dominance of blactx-m harbouring plasmids in shigella spp. circulating in southern vietnam.plasmid mediated antimicrobial resistance in the enterobacteriaceae is a global problem. the rise of ctx-m class extended spectrum beta lactamases (esbls) has been well documented in industrialized countries. vietnam is representative of a typical transitional middle income country where the spectrum of infectious diseases combined with the spread of drug resistance is shifting and bringing new healthcare challenges.201020544028
[the evolution of the etiological structure of shigellosis]. 201020734730
plasmon-induced inactivation of enteric pathogenic microorganisms with ag-agi/al2o3 under visible-light irradiation.the plasmon-induced photocatalytic inactivation of enteric pathogenic microorganisms in water using ag-agi/al(2)o(3) under visible-light irradiation was investigated. the catalyst was found to be highly effective at killing shigella dysenteriae (s. dysenteriae), escherichia coli (e. coli), and human rotavirus type 2 wa (hrv-wa). its bactericidal efficiency was significantly enhanced by hco(3)(-) and so(4)(2-) ions, which are common in water, while phosphate had a slightly positive effect on the ...201020734989
cytoskeleton-modulating effectors of enteropathogenic and enterohemorrhagic escherichia coli: a case for espb as an intrinsically less-ordered effector.enterohemorrhagic and enteropathogenic escherichia coli produce various effector proteins that are directly injected into the host-cell cytosol through the type iii secretion system. e. coli secreted protein (esp)b is one such effector protein, and affects host-cell morphology by reorganizing actin networks. unlike most globular proteins that have well-ordered, rigid structures, the structures of type iii secretion system effectors from pathogenic gram-negative bacteria, including espb, are ofte ...201020477867
sensitization of microcin j25-resistant strains by a membrane-permeabilizing peptide.microcin j25 (mccj25) is a plasmid-encoded, 21-amino-acid, antibacterial peptide produced by escherichia coli. mccj25 inhibits rna polymerase and the membrane respiratory chain. mccj25 uptake into e. coli-sensitive strains is mediated by the outer membrane receptor fhua and the inner membrane proteins tonb, exbb, exbd, and sbma. this peptide is active on some e. coli, salmonella, and shigella species strains, while other gram-negative bacteria, such as clinical isolates of enterobacter cloacae, ...201020802073
an outbreak of shigellosis due to shigella flexneri serotype 3a in a prison in iran.on june 16 and 17, 2007, the medical clinic of a prison in isfahan, iran received multiple reports of gastrointestinal illness among prisoners. a cross-sectional study was therefore undertaken to determine the extent, causative agent and possible source of the outbreak.201020804308
comparison of chromogenic biolog rainbow agar shigella/aeromonas with xylose lysine desoxycholate agar for isolation and detection of shigella spp. from foods.shigella outbreaks are widely reported throughout the world. however, it remains a challenge to isolate shigella spp. from foods by using conventional microbiological media. the main objective of this study was to determine the effectiveness of a novel chromogenic medium, rainbow agar shigella/aeromonas (rainbow agar), for the isolation and detection of shigella spp. in foods. all four shigella species, s. sonnei, s. flexneri, s. dysenteriae, and s. boydii, were studied. rainbow agar was compare ...201020819355
enhancement of reactive oxygen species production and chlamydial infection by the mitochondrial nod-like family member nlrx1.chlamydia trachomatis infections cause severe and irreversible damage that can lead to infertility and blindness in both males and females. following infection of epithelial cells, chlamydia induces production of reactive oxygen species (ros). unconventionally, chlamydiae use ros to their advantage by activating caspase-1, which contributes to chlamydial growth. nlrx1, a member of the nod-like receptor family that translocates to the mitochondria, can augment ros production from the mitochondria ...201020959452
prominent human health impacts from several marine microbes: history, ecology, and public health implications.this paper overviews several examples of important public health impacts by marine microbes and directs readers to the extensive literature germane to these maladies. these examples include three types of dinoflagellates (gambierdiscus spp., karenia brevis, and alexandrium fundyense), bmaa-producing cyanobacteria, and infectious microbes. the dinoflagellates are responsible for ciguatera fish poisoning, neurotoxic shellfish poisoning, and paralytic shellfish poisoning, respectively, that have pl ...201020976073
ikkα contributes to canonical nf-κb activation downstream of nod1-mediated peptidoglycan recognition.during pathogen infection, innate immunity is initiated via the recognition of microbial products by pattern recognition receptors and the subsequent activation of transcription factors that upregulate proinflammatory genes. by controlling the expression of cytokines, chemokines, anti-bacterial peptides and adhesion molecules, the transcription factor nuclear factor-kappa b (nf-κb) has a central function in this process. in a typical model of nf-κb activation, the recognition of pathogen associa ...201020976174
atypical class 1 integron coexists with class 1 and class 2 integrons in multi-drug resistant shigella flexneri isolates from china.the antimicrobial resistance and the character of integrons were determined in 58 shigella flexneri strains isolated from china. all isolates were multi-drug resistant and found to carry integrons of class 1 (94.8%), class 2 (100%), or both (94.8%). no inti3 was detected. the typical class 1 integrons were found in conjugative plasmids and could be transferred to the recipient e. coli dh5α. the gene cassettes of typical class 1 integrons dfra17-aada5 and dfra12-orff-aada2 were detected in 54 str ...201020976456
[susceptibility surveillance of clinical isolates to fluoroquinolone antimicrobial agents from 2003 to 2008: post-marketing study of prulifloxacin].yearly changes in the susceptibility of clinical isolates to ulifloxacin (ufx) and other fluoroquinolones were examined through surveys over 3 periods. in the first survey, 534 strains derived from 19 species were collected from clinical specimens during 6 months from december 2003 to may 2004. in the same way, 805 strains were collected from december 2005 to may 2006 in the second survey, and 863 strains were from december 2007 to may 2008 in the third survey. over these 3 study periods, the su ...201020976880
mutagenesis and chemical cross-linking suggest that wzz dimer stability and oligomerization affect lipopolysaccharide o-antigen modal chain length control.in shigella flexneri, the polysaccharide copolymerase (pcp) protein wzz(sf) confers a modal length of 10 to 17 repeat units (rus) to the o-antigen (oag) component of lipopolysaccharide (lps). pcps form oligomeric structures believed to be related to their function. to identify functionally important regions within wzz(sf), random in-frame linker mutagenesis was used to create mutants with 5-amino-acid insertions (termed wzz(i) proteins), and dna sequencing was used to locate the insertions. anal ...201020453100
carbon metabolism of intracellular bacterial pathogens and possible links to virulence.new technologies such as high-throughput methods and 13c-isotopologue-profiling analysis are beginning to provide us with insight into the in vivo metabolism of microorganisms, especially in the host cell compartments that are colonized by intracellular bacterial pathogens. in this review, we discuss the recent progress made in determining the major carbon sources and metabolic pathways used by model intracellular bacterial pathogens that replicate either in the cytosol or in vacuoles of infecte ...201020453875
acid stress response in enteropathogenic gammaproteobacteria: an aptitude for survival.enteric bacteria such as escherichia coli have acquired a wide array of acid stress response systems to counteract the extreme acidity encountered when invading the host's digestive or urinary tracts. these acid stress response systems are both enzyme and chaperone based. the 3 main enzyme-based acid resistance pathways are glutamate-, arginine-, and lysine-decarboxylase pathways. they are under a complex regulatory network allowing the bacteria to fine tune its response to the external environm ...201020453931
antioxidant, antibacterial and antigiardial activities of walsura robusta roxb.walsura robusta roxb. (family: meliaceae) is a well-known multi-purpose medicinal plant, and has been employed for a wide range of disease conditions without documented scientific data. in the current study, four pure isolated compounds, 3,4,5-trimethoxyphenyl beta-d-glucopyranoside (1), turpinionoside a (2), (+)-lyoniresinol 3alpha-o-beta-d-glucopyranoside (3) and (-)-lyoniresinol 3alpha-o-beta-d-glucopyranoside (4), were isolated from the leaves and twigs of w. robusta. biological evaluation f ...201020461627
preliminary foodnet data on the incidence of infection with pathogens transmitted commonly through food - 10 states, 2009.the foodborne diseases active surveillance network (foodnet) of cdc's emerging infections program conducts active, population-based surveillance in 10 u.s. states for all laboratory-confirmed infections with select enteric pathogens transmitted commonly through food. this report describes preliminary surveillance data for 2009 and trends in incidence since 1996. in 2009, a total of 17,468 laboratory-confirmed cases of infection were identified. in comparison with the first 3 years of surveillanc ...201020395935
nmr characterization of the interaction of the salmonella type iii secretion system protein sipd and bile salts.salmonella and shigella bacteria require the type iii secretion system (t3ss) to inject virulence proteins into their hosts and initiate infections. the tip proteins sipd and ipad are critical components of the salmonella and shigella t3ss, respectively. recently, sipd and ipad have been shown to interact with bile salts, which are enriched in the intestines, and are hypothesized to act as environmental sensors for these enteric pathogens. bile salts activate the shigella t3ss but repress the sa ...201020397637
innate ifn-gamma production by subsets of natural killer cells, natural killer t cells and gammadelta t cells in response to dying bacterial-infected macrophages.interferon-gamma (ifn-gamma) activation of macrophages is a crucial step in the early innate defence against bacterial infection. this innate ifn-gamma is thought to be produced mainly by natural killer (nk) cells through activation with interleukin (il)-12p70 secreted by macrophages and dendritic cells (dcs) that have sensed bacterial products. however, a number of reports have shown that bacterial stimuli are unable to induce macrophages and/or dcs to produce sufficient amounts of il-12p70 unl ...201020415785
production and immunogenicity of recombinant ferric enterobactin protein (fepa).ferric siderophore complexes are produced by most bacteria to acquire iron, a vital element. these complexes are transported across the outer membrane by receptor proteins commonly known as fepa (ferric enterobactin protein). in this study we attempted to evaluate the immunogenicity of the membrane protein fepa, aiming at inhibition of iron uptake to protect invasion of the host by the bacterium.201020418143
tracking the secretion of fluorescently labeled type iii effectors from single bacteria in real time.a large number of gram negative pathogens use a specialized needle-like molecular machine known as type iii secretion (t3s) system. this highly sophisticated molecular device consists of a basal body spanning the two bacterial membranes and a protruding needle structure that is connected to a distal translocator complex. the main features of the t3s system are (i) activation after host cellular membrane contact and (ii) the ability to "inject" effectors into host cells through the needle apparat ...201020419414
structures of the o-antigens of escherichia coli o13, o129, and o135 related to the o-antigens of shigella flexneri.o-polysaccharides (o-antigens) were isolated from escherichia coli o13, o129, and o135 and studied by chemical analyses along with 2d (1)h and (13)c nmr spectroscopy. they were found to possess a common -->2)-l-rha-(alpha1-->2)-l-rha-(alpha1-->3)-l-rha-(alpha1-->3)-d-glcnac-(beta1--> backbone, which is a characteristic structural motif of the o-polysaccharides of shigella flexneri types 1-5. in both the bacterial species, the backbone is decorated with lateral glucose residues or/and o-acetyl gr ...201020546712
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