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nleh effectors interact with bax inhibitor-1 to block apoptosis during enteropathogenic escherichia coli infection.the human pathogens enteropathogenic (epec) and enterohemorrhagic escherichia coli and the related mouse pathogen citrobacter rodentium subvert a variety of host cell signaling pathways via their plethora of type iii secreted effectors, including triggering of an early apoptotic response. epec-infected cells do not develop late apoptotic symptoms, however. in this study we demonstrate that the nleh family effectors, homologs of the shigella effector kinase ospg, blocks apoptosis. during epec inf ...201020133763
crystal structure of the dna-recognition component of the bacterial virus sf6 genome-packaging machine.in herpesviruses and many bacterial viruses, genome-packaging is a precisely mediated process fulfilled by a virally encoded molecular machine called terminase that consists of two protein components: a dna-recognition component that defines the specificity for packaged dna, and a catalytic component that provides energy for the packaging reaction by hydrolyzing atp. the terminase docks onto the portal protein complex embedded in a single vertex of a preformed viral protein shell called procapsi ...201020133842
a piglet model of acute gastroenteritis induced by shigella dysenteriae type 1.the lack of a standardized laboratory animal model that mimics key aspects of human shigellosis remains a major obstacle to addressing questions about pathogenesis, screening therapeutics, and evaluation of vaccines.201020136414
risk factors for sporadic shigellosis, foodnet 2005.an estimated 450,000 cases of shigellosis occur annually in the united states. outbreaks have been associated with food, water, child daycare centers, and men who have sex with men. however, for sporadic infections, which account for the majority of cases, risk exposures are poorly characterized.201020113209
structural and functional divergence of the newly identified gtric from its gtr family of conserved shigella flexneri serotype-converting glucosyltransferases.glucosyltransferases (gtrs) and o-acetyltransferase (oac) are integral membrane proteins embedded within the cytoplasmic membrane of shigella flexneri. gtrs and oac are responsible for unidirectional host serotype conversion by altering the epitopic properties of the bacterial surface lipopolysaccharide (lps) o-antigen. in this study, we present the membrane topology of a recently recognized gtr, gtric, which is known to mediate s. flenxeri serotype switching from 1a to 1c. the gtric topology is ...201020095950
a yersinia pestis guaba mutant is attenuated in virulence and provides protection against plague in a mouse model of infection.there is a need to develop effective countermeasures for yersinia pestis, the etiologic agent of plague and a potential bioterrorism agent. salmonella and shigella spp. deleted in the guaba genes involved in guanine biosynthesis have been shown to be attenuated in vivo. in this study, we sought to determine whether deletion of the guaba operon would render y. pestis auxotrophic for guanine and avirulent; such a strain could serve as a live attenuated plague vaccine candidate. a y. pestis guaba m ...201020096773
antibacterial activity of artemisia nilagirica leaf extracts against clinical and phytopathogenic bacteria.the six organic solvent extracts of artemisia nilagirica were screened for the potential antimicrobial activity against phytopathogens and clinically important standard reference bacterial strains.201020109237
new enterovirulent escherichia coli serogroup 64474 showing antigenic and genotypic relationships to shigella boydii 16.studies based on the analysis of housekeeping genes indicate that escherichia coli and all shigella species, except for shigella boydii type 13, belong to a single species. this study analysed the phenotypic and genotypic characteristics of 23 e. coli strains isolated in different countries from faecal specimens taken from children with diarrhoea. strains were identified using the vitek system and typed with rabbit sera obtained against 186 somatic and 53 flagellar e. coli antigens and against 4 ...201020075111
selective deletion of cd8(+) cells upregulated by caspases-1 via il-18 in mice immunized with major outer membrane protein of shigella dysenteriae 1 following infection.introduction: mucosal lymphoid changes were observed in cryopreserved rectal tissues obtained from balb/c mice infected with shigella dysenteriae 1, immunized with 57-kda major antigenic outer membrane protein, and infection after immunization. discussion: our data suggested that caspase-3 is downregulated in cd4(+) cells of immunized balb/c mice following infection with substantial increased expression of interleukin (il)-2 and interferon (ifn)-gamma, while caspase-1 is upregulated in cd8(+) ce ...201020084439
the extreme c terminus of shigella flexneri ipab is required for regulation of type iii secretion, needle tip composition, and binding.type iii secretion systems (t3sss) are widely distributed virulence determinants of gram-negative bacteria. they translocate bacterial proteins into host cells to manipulate them during infection. the shigella t3ss consists of a cytoplasmic bulb, a transmembrane region, and a hollow needle protruding from the bacterial surface. the distal tip of mature, quiescent needles is composed of ipad, which is topped by ipab. physical contact with host cells initiates secretion and leads to assembly of a ...201020086081
chaperonin activity modulates codon adaptation. 201020087337
groel dependency affects codon usage--support for a critical role of misfolding in gene evolution.it has recently been suggested that the use of optimal codons limits mistranslation-induced protein misfolding, yet evidence for this remains largely circumstantial. in contrast, molecular chaperones have long been recognized to play crucial roles in misfolding prevention and remedy. we propose that putative error limitation in cis can be elucidated by examining the interaction between codon usage and chaperoning processes. using escherichia coli as a model system, we find that codon optimality ...201020087338
th17 cells are the dominant t cell subtype primed by shigella flexneri mediating protective immunity.the t cell response to shigella, the causative agent of bacillary dysentery, remains poorly understood. using a murine model of infection, we report that shigella flexneri primes predominately il-17a- and il-22-producing th17 cells. shigella-specific th1 cells are only significantly induced on secondary infection, whereas specific th2 and cd8(+) t cells are undetectable. apart from th17 cells that are primed in a mhc class ii- and il-6-dependent, but il12/23p40-independent manner, we identified ...201020089698
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.201020091606
the proteome of shigella flexneri 2a 2457t grown at 30 and 37 degrees c.to upgrade the proteome reference map of shigella flexneri 2a 2457t, the protein expression profiles of log phase and stationary phase cells grown at 30 and 37 degrees c were thoroughly analyzed using multiple overlapping narrow ph range (between ph 4.0 and 11.0) two-dimensional gel electrophoresis. a total of 723 spots representing 574 protein entries were identified by maldi-tof/tof ms, including the majority of known key virulence factors. 64 hypothetical proteins and six misannotated protein ...201020164057
influences of hydraulic loading rate on svoc removal and microbial community structure in drinking water treatment biofilters.six biofilters were used for advanced treatment of yangtze river source water to investigate the effects of hydraulic loading rate (hlr) on pollutant removal and microbial community. hlr was found to exert significant influences on the removal efficiency of the conventional pollutants and 24 detectable semivolatile organic compounds (svocs). more than 85% of chemical oxygen demand and assimilable organic carbon was removed at the optimal hlr of 3.0 m h(-1). with the increase of hlr, svoc removal ...201020189298
disruption of the rickettsia rickettsii sca2 autotransporter inhibits actin-based motility.rickettsii rickettsii, the etiologic agent of rocky mountain spotted fever, replicates within the cytosol of infected cells and uses actin-based motility to spread inter- and intracellularly. although the ultrastructure of the actin tail and host proteins associated with it are distinct from those of listeria or shigella, comparatively little is known regarding the rickettsial proteins involved in its organization. here, we have used random transposon mutagenesis of r. rickettsii to generate a s ...201020194597
specific igg activity against diarrheagenic bacteria in bovine immune milk and effect of ph on its antigen-binding activity upon heating.bovine colostrum and milk antibodies of calving and lactating cows immunized with a multivalent vaccine consisting of whole cells of three different species of pathogenic bacteria including four strains of enterotoxigenic escherischia coli, five strains of enteropathogenic esch. coli, three strains of enteroinvasive esch. coli, two strains of samonella typhi, and one strain each of shigellia dysenteriae, sh. sonnei and sh. flexneri were generated, respectively. a significantly elevated activity ...201020196896
mst (molecular serotyping tool): a program for computer-assisted molecular identification of escherichia coli and shigella o antigens.escherichia coli and shigella o antigens can be inferred using the rfb-restriction fragment length polymorphism (rflp) molecular test. we present herein a dynamic programming algorithm-based software to compare the rfb-rflp patterns of clinical isolates with those in a database containing the 171 previously published patterns corresponding to all known e. coli/shigella o antigens.201020200287
structure, biological functions and applications of the ab5 toxins.ab(5) toxins are important virulence factors for several major bacterial pathogens, including bordetella pertussis, vibrio cholerae, shigella dysenteriae and at least two distinct pathotypes of escherichia coli. the ab(5) toxins are so named because they comprise a catalytic a-subunit, which is responsible for disruption of essential host functions, and a pentameric b-subunit that binds to specific glycan receptors on the target cell surface. the molecular mechanisms by which the ab(5) toxins ca ...201020202851
prevalence of plasmid-mediated quinolone-resistance determinants in shigella flexneri isolates from anhui province, china.quinolones are used extensively to treat shigella flexneri infection, and plasmid-mediated quinolone resistance (pmqr) determinants were recently reported. a total of 26 s. flexneri isolates collected from anhui province, china, in 2005 were screened for pmqr determinants, bla gene, gyra and parc genes, by pcr and sequencing. pmqr determinants were present in 53.8% (14 of 26) of isolates and qnra(1), qnrs(1), qnrs(2), aac(6')-ib-cr and qepa were present in 30.8, 11.5, 3.8, 19.2 and 11.5% of thos ...201020203702
[rectal prolapse in a neonate with shigella diarrhea].a case of neonatal rectal prolapse during shigella diarrhea is described. a 10 days neonate exclusively breast fed, whose 2 years old brother has had the same process 2 weeks ago. medical treatment with intravenous ceftriaxone resolved rectal prolapse in 48 hours. stool cultures showed the presence of shigella flexneri ii resistant to amoxicillin; blood and cerebrospinal fluid, cultures were negative. conclusion: rectal prolapse is an uncommon complication seen in infants with shigella diarrhea. ...201020204227
synthesis, in-vitro antimicrobial and cytotoxic studies of novel azetidinone derivatives.developing novel antimicrobial drugs is increasingly important in the modern pharmaceutical industry. a series of novel 3-chloro-4-[4-(2-oxo-2h-chromen-4-ylmethoxy)phenyl]-1-phenylazetidin-2-ones 5a-o have been synthesized from 4-bromomethylcoumarins 1a-e and 4-aryliminomethyl-phenols 3a-c. these compounds were screened for their in-vitro antibacterial activity against two gram-positive (staphylococcus aureus and vancomycin resistant enteroccoccus) and two gram-negative (escherichia coli and shi ...201020205197
induction of apoptosis by shiga toxins.shiga toxins comprise a family of structurally and functionally related protein toxins expressed by shigella dysenteriae serotype 1 and multiple serotypes of escherichia coli. while the capacity of shiga toxins to inhibit protein synthesis by catalytic inactivation of eukaryotic ribosomes has been well described, it is also apparent that shiga toxins trigger apoptosis in many cell types. this review presents evidence that shiga toxins induce apoptosis of epithelial, endothelial, leukocytic, lymp ...201020210553
identification and characterization of ctx-m-producing shigella isolates in the united states. 201020211893
prolonged remission of chronic reactive arthritis treated with three infusions of infliximab.reactive arthritis is generally self-remitting but can be chronic. predictors of chronicity include hla b27 positivity and triggering infections with yersinia, salmonella, shigella, or chlamydia. nonsteroidal antiinflammatory drugs and local steroids are the mainstays, with some evidence for disease modifying antirheumatic drugs. limited evidence suggests effectiveness of tumor necrosis factor antagonists. we report the case of reactive arthritis following a chlamydia urinary tract infection pro ...201020216128
autotransporter passenger proteins: virulence factors with common structural themes.autotransporter proteins are virulence factors associated with a wide variety of diseases caused by pathogenic gram-negative bacteria, and they play a variety of roles in pathogenesis including disabling host defences and mediating colonization. pertactin, a key component of the whooping cough vaccine, is an autotransporter protein. a large sub-family of the autotransporters carries a trypsin-like protease domain, but these enzymes have different substrates and functions. the unique export proce ...201020217035
[role of galactose-specific receptor--lectin in bactericidal activity of hemolysin of vibrio cholerae non o1/o139].to study the role lectin galactose-specific receptor of vibrio cholerae hemolysin in receptor mechanisms of bacterial cells lysis.201020218337
shigella mediated depletion of macrophages in a murine breast cancer model is associated with tumor regression.a tumor promoting role of macrophages has been described for a transgenic murine breast cancer model. in this model tumor-associated macrophages (tams) represent a major component of the leukocytic infiltrate and are associated with tumor progression. shigella flexneri is a bacterial pathogen known to specificly induce apotosis in macrophages. to evaluate whether shigella-induced removal of macrophages may be sufficient for achieving tumor regression we have developed an attenuated strain of s. ...201020221397
disease burden of post-infectious irritable bowel syndrome in the netherlands.post-infectious irritable bowel syndrome (pi-ibs) has been established as a sequel of infectious intestinal disease (iid). the aim of this study was to estimate the burden of pi-ibs caused by the pathogens campylobacter, salmonella and shigella, and to compare this with other outcomes associated with these pathogens. the attributable risk of pi-ibs due to bacterial pathogens was calculated and linked to national data on gastroenteritis incidence and measures for severity and duration of illness ...201020223049
a new paradigm of bacteria-gut interplay brought through the study of shigella.bacteria-gut epithelial interplay and the mucosal immune response are the most critical issues in determining the fate of bacterial infection and the severity of diseases. shigella species (abbreviated here as shigella), the causative agent of bacillary dysentery (shigellosis), are highly adapted human pathogens that are capable of invading and colonizing the intestinal epithelium, which results in severe inflammatory colitis. shigella secrete a large and diverse number (more then 50) of effecto ...201020228623
[shigella bacteremia dysentery in an adult]. 201020232025
high-throughput screening of the virulence regulator virf: a novel antibacterial target for shigellosis.shigella flexneri is a human enteropathogen that infects about 165 million people and claims more than 1 million lives per year worldwide. although shigellosis has been considered a disease of the "third world," like many other contagious diseases, it does occur in developed countries. the emergence of drug and multidrug-resistant strains of shigella emphasizes the need for novel antibiotic development. virf, an arac-type transcriptional regulator, is responsible for the expression of all downst ...201020237205
phenotypic and genotypic characterization of shigella spp. with reference to its virulence genes and antibiogram analysis from river narmada.water samples of the river narmada from origin to end were analyzed for the presence of shigellae. analysis of 40 water samples by biotyping, serotyping, and molecular typing were done. out of all 40 isolates, 23 were identified as shigella flexneri, 10 as shigella sonnei, and seven as shigella dysenteriae. serotyping was found to be a better identification method than biotyping since biotyping was not found to be very sharp. in the present investigation, amplified ribosomal dna restriction anal ...201019501495
biennial hyperepidemic shigellosis in an observant jewish community.we aimed to study patterns of shigellosis in a large observant jewish community in israel and to describe local interventions during outbreaks. surveillance data from the ministry of health were used to calculate incidence rates in 1998-2006, both in the city of bene beraq and the tel aviv district. information on isolates was collected from the bacteriological laboratory of a community hospital. public notices and educational conferences conveyed a message to increase personal hygiene and keep ...201019602299
a new multiplex pcr for differential identification of shigella flexneri and shigella sonnei and detection of shigella virulence determinants.most of the multiplex pcr (mpcr) used to identify shigella do not discriminate between shigella species or serotypes. we designed a mpcr to differentiate between s. flexneri and s. sonnei strains based on the detection of markers associated with the she pathogenicity island described in shigella. in addition, specific primers were included to detect the shigella virulence determinants shet-1 and shet-2 enterotoxin genes. the analysis of 304 shigella strains from chile and 79 shigella strains fro ...201019765332
structure of the heme/hemoglobin outer membrane receptor shua from shigella dysenteriae: heme binding by an induced fit mechanism.shigella dysentriae and other gram-negative human pathogens are able to use iron from heme bound to hemoglobin for growing. we solved at 2.6 a resolution the 3d structure of the tonb-dependent heme/hemoglobin outer membrane receptor shua from s. dysenteriae. shua binds to hemoglobin and transports heme across the outer membrane. the structure consists of a c-terminal domain that folds into a 22-stranded transmembrane beta-barrel, which is filled by the n-terminal plug domain. one distal histidin ...201019731368
clinical practice. today's understanding of the haemolytic uraemic syndrome.the haemolytic uraemic syndrome (hus) includes the triad of haemolytic anaemia, thrombocytopenia, and acute renal failure. the classical form [d(+) hus] is caused by infectious agents, and it is a common cause of acute renal failure in children. the enterohaemorrhagic escherichia coli-producing shiga toxin (stx) is the most common infectious agent causing hus. other infectious agents are shigella and streptococcus pneumoniae. infections by s. pneumoniae can be particularly severe and has a highe ...201019707787
requirement for formin-induced actin polymerization during spread of shigella flexneri.actin polymerization in the cytosol and at the plasma membrane is locally regulated by actin nucleators. several microbial pathogens exploit cellular actin polymerization to spread through tissue. the movement of the enteric pathogen shigella flexneri, both within the cell body and from cell to cell, depends on actin polymerization. during intercellular spread, actin polymerization at the bacterial surface generates protrusions of the plasma membrane, which are engulfed by adjacent cells. in the ...201019841078
genetic diversity of o157:h7 and non-o157 verocytotoxigenic escherichia coli from argentina inferred from multiple-locus variable-number tandem repeat analysis (mlva).although serotype o157:h7 has been implicated in most cases of haemolytic-uraemic syndrome (hus), there is growing concern about non-o157 serotypes of verocytotoxigenic escherichia coli (vtec). multiple-locus variable-number tandem repeat analysis (mlva) has been focused on the specific typing of o157:h7 isolates, but recently, a generic mlva assay for e. coli and shigella has been developed. we performed a study of the polymorphism in 7 generic vntr loci both in vtec o157:h7 and non-o157 isolat ...201019850517
pretreatment of epithelial cells with rifaximin alters bacterial attachment and internalization profiles.rifaximin is a poorly absorbed semisynthetic antibiotic derivative of rifampin licensed for use in the treatment of traveler's diarrhea. rifaximin reduces the symptoms of enteric infection, often without pathogen eradication and with limited effects on intestinal flora. epithelial cells (hep-2 [laryngeal], hct-8 [ileocecal], a549 [lung], and hela [cervical]) were pretreated with rifaximin (or control antibiotics) prior to the addition of enteroaggregative escherichia coli (eaec). eaec adherence ...201019858255
immunomodulation using genetically engineered bacteria for type iii-mediated delivery of heterologous antigens and cytokines: potential application in vaccine and therapeutical developments.the rational design of new approaches aiming to improve antigen or drug delivery remains a major challenge in numerous vaccine and therapeutical strategies. studies on genetically engineered bacteria have led to significant progress in the delivery of heterologous proteins. yet, the efficiency of such recombinant bacteria relies particularly on their ability to deliver sufficient amount of the drug to intended cell tissues. gram-negative bacteria like salmonella, shigella, yersinia and pseudomon ...201019778176
the escherichia coli o149 rfb gene cluster and its use for the detection of porcine e. coli o149 by real-time pcr.pcr or hybridization assays are widely used for the identification and detection of various escherichia coli serogroups and serotypes. this study explored this approach for the detection of e. coli o149 in pigs, a dominant serogroup among those associated with porcine post-weaning diarrhea (pwd) worldwide. for this purpose, we sequenced the o antigen (rfb) gene cluster of a representative enterotoxigenic e. coli (etec) o149:h10 strain and identified a 2kbp region specific for the o149 rfb gene c ...201019733452
evaluation of isolation methods for pathogenic yersinia enterocolitica from pig intestinal content.the aim of this study was to evaluate the efficiency of four isolation methods for the detection of pathogenic yersinia enterocolitica from pig intestinal content.201019735331
automated use of whonet and satscan to detect outbreaks of shigella spp. using antimicrobial resistance phenotypes.antimicrobial resistance is a priority emerging public health threat, and the ability to detect promptly outbreaks caused by resistant pathogens is critical for resistance containment and disease control efforts. we describe and evaluate the use of an electronic laboratory data system (whonet) and a space-time permutation scan statistic for semi-automated disease outbreak detection. in collaboration with whonet-argentina, the national network for surveillance of antimicrobial resistance, we appl ...201019796449
survey of bacterial populations present in us-produced linerboard with high recycle content.to survey paperboard products from 17 us mills for bacterial populations and for bacteria potentially harmful to human health.201019645765
differential expression of enteric neuroimmune-network in invasive and acute watery diarrhoea.we aimed to evaluate the changes of nerve morphology and distribution of neurotransmitters and neuropeptides in the rectum of shigella flexneri-infected patients and in the duodenum of vibrio cholerae o1-infected patients. nerve morphology was observed by transmission electron microscopy. immunoreactivity of nerve growth factor (ngf), neurotransmitters and neuropeptides in tissues were studied by immunohistochemistry. ultrastructural analysis of intestinal biopsy revealed persisting axons degene ...201019650770
lactobacilli inhibit shigella dysenteriae 1 induced pro-inflammatory response and cytotoxicity in host cells via impediment of shigella-host interactions.shigella dysenteriae type 1 dysentery is a major cause of morbidity and mortality in children from less developed and developing countries. the present study explores the hypothesis that lactobacilli protect the host cell during s. dysenteriae type 1 infection and its mechanism of action.201019535308
diarrhea in children less than two years of age with known hiv status in kisumu, kenya.to compare the frequency and etiology of diarrhea in children aged less than 2 years with known hiv status.201019664950
shigella enterotoxin-2 is a type iii effector that participates in shigella-induced interleukin 8 secretion by epithelial cells.we have previously described a protein termed shigella enterotoxin 2 (shet-2), which induces rises in short-circuit current in rabbit ileum mounted in the ussing chamber. published reports have postulated that shet-2 may be secreted by the shigella type iii secretion system (t3ss). in this study, we show that shet-2 secretion into the extracellular space requires the t3ss in shigella flexneri 2a strain 2457t and a shet-2-tem fusion was translocated into epithelial cells in a t3ss-dependent manne ...201121219446
decreased susceptibility to ciprofloxacin among shigella isolates in the united states, 2006 to 2009.we characterized 20 shigella isolates with decreased susceptibility to fluoroquinolones. most patients (80%) from whom a travel history was obtained reported travel to south or southeast asia. mutations within the quinolone resistance determining regions of gyra and parc and plasmid-mediated resistance determinants (qnrb, qnrs, and aac(6')-ib-cr) were identified. the rise in antimicrobial resistance among shigella isolates may necessitate the increased use of extended-spectrum cephalosporins or ...201121220535
two promoters and two translation start sites control the expression of the shigella flexneri outer membrane protease icsp.the shigella flexneri outer membrane protease icsp proteolytically cleaves the actin-based motility protein icsa from the bacterial surface. the icsp gene is monocistronic and lies downstream of an unusually large intergenic region on the shigella virulence plasmid. in silico analysis of this region predicts a second transcription start site 84 bp upstream of the first. primer extension analyses and beta-galactosidase assays demonstrate that both transcription start sites are used. both promoter ...201121225241
structural and functional studies indicate that the epec effector, espg, directly binds p21-activated kinase.bacterial pathogens secrete effectors into their hosts that subvert host defenses and redirect host processes. espg is a type three secretion effector with a disputed function that is found in enteropathogenic escherichia coli. here we show that espg is structurally similar to vira, a shigella virulence factor; espg has a large, conserved pocket on its surface; espg binds directly to the amino-terminal inhibitory domain of human p21-activated kinase (pak); and mutations to conserved residues in ...201121235237
core and panmetabolism in escherichia coli.escherichia coli exhibits a wide range of lifestyles encompassing commensalism and various pathogenic behaviors which its highly dynamic genome contributes to develop. how environmental and host factors shape the genetic structure of e. coli strains remains, however, largely unknown. following a previous study of e. coli genomic diversity, we investigated its diversity at the metabolic level by building and analyzing the genome-scale metabolic networks of 29 e. coli strains (8 commensal and 21 p ...201121239590
immunology of gut mucosal vaccines.understanding the mechanisms underlying the induction of immunity in the gastrointestinal mucosa following oral immunization and the cross-talk between mucosal and systemic immunity should expedite the development of vaccines to diminish the global burden caused by enteric pathogens. identifying an immunological correlate of protection in the course of field trials of efficacy, animal models (when available), or human challenge studies is also invaluable. in industrialized country populations, l ...201121198669
dysbiosis of the faecal microbiota in patients with crohn's disease and their unaffected relatives.a general dysbiosis of the intestinal microbiota has been established in patients with crohn's disease (cd), but a systematic characterisation of this dysbiosis is lacking. therefore the composition of the predominant faecal microbiota of patients with cd was studied in comparison with the predominant composition in unaffected controls. whether dysbiosis is present in relatives of patients cd was also examined.201121209126
volatile compounds and antimicrobial and antioxidant activities of the essential oils of the needles of pinus densiflora and pinus thunbergii.to investigate the volatile compounds and the antibacterial and antioxidant effects of the essential oils of pinus densiflora needles (epdn) and pinus thunbergii needles (eptn), the volatile compounds of steam-distilled essential oils were analysed by gas chromatography-mass spectrometry. antibacterial activities were analysed by performing disc-agar diffusion assay and determining the minimum inhibitory concentrations (mics) of the essential oils. antioxidant activities were analysed via radica ...201121213230
structural variability of endotoxins from r-type isogenic mutants of shigella sonnei.the structural variations in the rough-type endotoxins [lipopolysaccharides (lpss)] of shigella sonnei mutant strains (s. sonnei phase ii-4303, r41, 562h and 4350) were investigated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (maldi-tof-ms) and tandem ms. a series of s. sonnei mutants had previously been the subject of analytical studies on the biosynthesis of heptose components in the core oligosaccharide region of lpss. this study gives a complete overview o ...201121184397
shigellosis outbreak linked to canteen-food consumption in a public institution: a matched case-control study.summaryon 13 november 2009, the authorities of flemish brabant, belgium, received an alert concerning a potential outbreak of shigella sonnei at a public institution. a study was conducted to assess the extent, discover the source and to implement further measures. we performed a matched case-control study to test an association between shigellosis and canteen-food consumption. water samples and food handlers' faecal samples were tested. the reference laboratory characterized the retrospectively ...201121281549
enteric glial cells: new players in mucosal defence against bacteria? 201121282131
isolation and partial characterisation of a novel lectin from aegle marmelos fruit and its effect on adherence and invasion of shigellae to ht29 cells.lectins are a class of ubiquitous proteins/glycoproteins that are abundantly found in nature. lectins have unique carbohydrate binding property and hence have been exploited as drugs against various infectious diseases. we have isolated one such novel lectin from the fruit pulp of aegle marmelos. the isolated lectin was partially characterised and its effect against shigella dysenteriae infection was evaluated. the isolated lectin was found to be a dimeric protein with n-acetylgalactosamine, man ...201121283697
purification and characterization of a ca2+-dependent novel lectin from nymphaea nouchali tuber with antiproliferative activities.a lectin (termed nntl) was purified from the extracts of nymphaea nouchali tuber followed by anion-exchange chromatography on deae-cellulose, hydrophobic chromatography on hitrap phenyl hp and by repeated anion-exchange chromatography on hitrap q ff column. the molecular mass of the purified lectin was 27.0 ± 1.0 kda, as estimated by sds/page both in the presence and in the absence of 2-mercaptoethanol. nntl was an o-nitrophenyl ß-d-galactopyranoside sugar-specific lectin that agglutinated rat, ...201121291421
seizure and altered mental status in a 12-year-old child with shigella sonnei gastroenteritis.we report a case of shigella-associated altered mental status and seizure in a 12-year-old boy. although seizure is a known complication of shigellosis, it is quite unusual in patients older than 9 years. this case illustrates the importance of considering the diagnosis of shigellosis in any pediatric patient with altered mental status or seizure in the context of gastrointestinal symptoms such as diarrhea.201121293224
development of a dna microarray for detection and identification of legionella pneumophila and ten other pathogens in drinking water.the safety and accessibility of drinking water are major concerns throughout the world. consumption of water contaminated with infectious agents, toxic chemicals or radiological hazards represents a significant health risk and is strongly associated with mortality. therefore, we have developed an oligonucleotide-based microarray using the sequences of 16s-23s rdna internal transcribed spacer regions (its) and the gyrase subunit b gene (gyrb) found in the most prevalent and devastating waterborne ...201121276629
strategies to overcome extended-spectrum ß-lactamases (esbls) and ampc ß-lactamases in shigellae.oral cephalosporins and mecillinam are used to treat shigella infections, but are compromised by extended-spectrum ß-lactamases (esbls) and plasmid ampc ß-lactamases. potential solutions include combining an oral or intravenous cephalosporin with a ß-lactamase inhibitor (bli) or using an oral penem. these strategies were examined using escherichia coli transconjugants and clinical isolates with esbls or ampc, as a proxy for shigellae. the clinical and laboratory standards institute agar dilution ...201121276715
role of intestinal bacteria in gliadin-induced changes in intestinal mucosa: study in germ-free rats.celiac disease (cd) is a chronic inflammatory disorder of the small intestine that is induced by dietary wheat gluten proteins (gliadins) in genetically predisposed individuals. the overgrowth of potentially pathogenic bacteria and infections has been suggested to contribute to cd pathogenesis. we aimed to study the effects of gliadin and various intestinal bacterial strains on mucosal barrier integrity, gliadin translocation, and cytokine production.201121249146
genomic characterization of asymptomatic escherichia coli isolated from the neobladder.the replacement of the bladder with a neobladder made from ileal tissue is the prescribed treatment in some cases of bladder cancer or trauma. studies have demonstrated that individuals with an ileal neobladder have recurrent colonization by escherichia coli and other species that are commonly associated with urinary tract infections; however, pyelonephritis and complicated symptomatic infections with ileal neobladders are relatively rare. this study examines the genomic content of two e. coli i ...201121252277
analysis of shigella flexneri-mediated infections in model organism caenorhabditis elegans.shigella flexneri is the causative agent of bacillary dysentery and generates a significant global disease burden. the aim of this study was to analyze the pathogenesis and host immune response, at both the physiological and molecular level, using the model organism caenorhabditis elegans, in response to s. flexneri. c. elegans is a nematode that responds to infection with a simple innate immune system, key aspects of which have been shown to be conserved.201121254954
shiga toxin and its use in targeted cancer therapy and imaging.shiga and the shiga-like toxins are related protein toxins produced by shigella dysenteriae and certain strains of escherichia coli. these toxins are composed of two non-covalently attached, modular parts: the a moiety (stxa) containing the enzymatically active a1 fragment, and the non-toxic, pentameric binding moiety (stxb). stx binds specifically to the glycosphingolipid globotriaosylceramide (gb3) at the surface of target cells and is then internalized by endocytosis. subsequently, in toxin-s ...201121255370
autophagy targeting of listeria monocytogenes and the bacterial countermeasure.autophagy acts as an intrinsic defense system against intracellular bacterial survival. recently, multiple cellular pathways that target intracellular bacterial pathogens to autophagy have been described. these include the atg5/lc3 pathway, which targets shigella, the ubiquitin (ub)-ndp52-lc3 pathway, which targets group a streptococcus (gas) and salmonella typhimurium, the ub-p62-lc3 pathway, which targets mycobacterium tuberculosis, listeria monocytogenes and s. typhimurium, and the diacylglyc ...201121193840
efficient screening of a novel antimicrobial peptide from jatropha curcas by cell membrane affinity chromatography.a novel method named cell membrane affinity chromatography was used to screen antimicrobial peptides from jatropha curcas . a cationic antimicrobial peptide (kvflglk, jcpep7) was successfully isolated and identified. antimicrobial assays indicated that jcpep7 was active against the tested microorganisms ( salmonella typhimurium atcc 50013, shigella dysenteriae atcc 51302, pseudomonas aeruginosa atcc 27553, staphylococcus aureus atcc 25923, bacillus subtilis atcc 23631, and streptococcus pneumoni ...201121268582
effect of freeze-drying on viability and in vitro probiotic properties of a mixture of lactic acid bacteria and yeasts isolated from kefir.the effect of freeze-drying on viability and probiotic properties of a microbial mixture containing selected bacterial and yeast strains isolated from kefir grains (lactobacillus kefir, lactobacillus plantarum, lactococcus lactis, saccharomyces cerevisiae and kluyveromyces marxianus) was studied. the microorganisms were selected according to their potentially probiotic properties in vitro already reported. two types of formulations were performed, a microbial mixture (mm) suspended in milk and a ...201120822567
serotypes and extended-spectrum β-lactamase types of clinical isolates of shigella spp. from the zhejiang province of china.to understand the distribution of the serotypes of shigella spp. and to investigate the drug-resistant genes of extended-spectrum β-lactamases (esbls) in shigella in zhejiang province, we have collected clinically isolated shigella isolates from 2 hospitals in zhejiang province during august to december of 2006. there are 11 shigella flexneri and 13 shigella sonnei isolates, respectively. among the 11 s. flexneri, 9 are serotype f4 and the remaining 2 are f1a and f2a. antimicrobial susceptibilit ...201121146721
multiplex polymerase chain reaction method discriminating escherichia coli and shigella sp.to distinguish between escherichia coli and other bacteria that have similar biochemical characteristics, 3 polymerase chain reaction techniques were combined. the primer sets cyda-f2-a2 and cyda-r2-a2 were designed to amplify 605 base pairs of nucleotide sequence specific for the cyda gene of escherichia coli; primer sets lacz-f-a and lacz-r-a to amplify 1,023 bp of nucleotide sequence specific for the lacz gene of escherichia coli; and primers laca-f2-a2 and laca-r2-a2 to amplify 325 bp of nucle ...201121060994
the crystal structures of the salmonella type iii secretion system tip protein sipd in complex with deoxycholate and chenodeoxycholate.the type iii secretion system (t3ss) is a protein injection nanomachinery required for virulence by many human pathogenic bacteria including salmonella and shigella. an essential component of the t3ss is the tip protein and the salmonella sipd and the shigella ipad tip proteins interact with bile salts, which serve as environmental sensors for these enteric pathogens. sipd and ipad have long central coiled coils and their n-terminal regions form α-helical hairpins and a short helix α3 that pack ...201121031487
a disposable immunosensor for shigella flexneri based on multiwalled carbon nanotube/sodium alginate composite electrode.a novel shigella flexneri immunosensor based on horseradish peroxidase-labeled antibodies to s. flexneri (hrp-anti-s. flexneri) immobilized by physical adsorption on the multiwalled carbon nanotube (mwcnt)/sodium alginate (sa) composite modified screen-printed electrode surface was successfully fabricated. in this strategy, mwcnt/sa biocomposite acted as the matrix to adsorb and immobilize hrp-anti-s. flexneri. the modified electrodes were characterized with an atomic force microscope and cyclic ...201120816661
antidiarrheal activity, chemical and toxicity profile of berberis aristata.context: this study evaluated the in vitro and in vivo antidiarrheal activity, oral acute toxicological profile, and developed a chemical fingerprint of berberis aristata linn. (berberidaceae). materials and methods: the ethanol (by maceration) and aqueous (by soxhlet) extracts of berberis aristata bark were used for the study. the study involved the antimicrobial (minimum inhibitory concentration (mic) and minimum bactericidal concentration (mbc) by micro dilution) and antidiarrheal (castor oil ...201120738174
community perceptions of bloody diarrhoea in an urban slum in south asia: implications for introduction of a shigella vaccine.understanding local perceptions of disease causation could help public health officials improve strategies to prevent bloody diarrhoea. a cross-sectional survey was conducted in dhaka, bangladesh to elicit community beliefs about the causes of and prevention strategies for bloody diarrhoea. between march and june 2003, we interviewed 541 randomly selected respondents. overall, 507 (93%) respondents perceived that a vaccine could prevent bloody diarrhoea. if a vaccine provided lifetime protection ...201120546637
changing species distribution and antimicrobial susceptibility pattern of shigella over a 29-year period (1980-2008).we studied changes in species distribution and antimicrobial resistance patterns of shigella during 1980-2008, using the diarrhoeal diseases surveillance system of dhaka hospital of icddr,b. in hospitalized patients shigella prevalence decreased steadily from 8-12% in the 1980s to 3% in 2008. endemic s. flexneri was the most commonly isolated species (54%). epidemic s. dysenteriae type 1 had two peaks in 1984 and 1993, but was not found after 2000, except for one case in 2004. the therapeutic op ...201120478088
development of a pcr protocol for the detection of escherichia coli o157:h7 and salmonella spp. in surface water.escherichia coli o157:h7 and salmonella are pathogenic microorganisms that can cause severe gastrointestinal illness in humans. these pathogens may be transmitted in a variety of ways, including food and water. the presence of salmonella and e. coli o157:h7 in surface waters constitutes a potential threat to human health when used for either drinking or recreation. as with most waterborne pathogens, salmonella and e. coli o157:h7 are difficult to detect and enumerate with accuracy in surface wat ...201120714926
Morning Glory Resin Glycosides as Modulators of Antibiotic Activity in Multidrug-Resistant Gram-Negative Bacteria.Twenty-six microbiologically inactive (MIC >?512?µg/mL) convolvulaceous resin glycosides ( 1- 26) were tested for resistance modulatory activity IN VITRO against ESCHERICHIA COLI Rosetta-gami and two nosocomial pathogens, SALMONELLA TYPHI and SHIGELLA FLEXNERI. These compounds exerted a potentiation effect of the clinically useful antibiotics tetracycline, kanamycin, and chloramphenicol against the tested gram-negative bacteria by increasing antibiotic susceptibility up to 32-fold at concent ...201122002849
Development of a multiplex PCR assay targeting O-antigen modification genes for molecular serotyping of Shigella flexneri.Shigella flexneri is the major Shigella species that causes diarrheal disease in developing countries. It is further subdivided into 15 serotypes based on O-antigen structure. Serotyping of S. flexneri is important for epidemiological purposes. In this study, we developed a multiplex PCR assay targeting the O-antigen synthesis gene wzx and the O-antigen modification genes gtrI, gtrIC, gtrII, oac, gtrIV, gtrV, and gtrX for molecular serotyping of S. flexneri. The multiplex PCR assay contained eig ...201121880974
a case of reactive arthritis after salmonella enteritis in in a 12-year-old boy.reactive arthritis comprises a subgroup within infection-associated arthritides in genetically susceptible hosts. researchers and clinicians recognize two clinical forms of reactive arthritis which occurs after genitourinary tract infection and after gastrointestinal tract infection. chlamydia infection has been implicated as the most common agent associated with post-venereal reactive arthritis. studies have proposed shigella infection, salmonella infection, or yersinia infection as the microor ...201122025926
Use of a DNA microarray for detection and identification of bacterial pathogens associated with fishery products.We established a microarray for the simultaneous detection and identification of diverse putative pathogens often associated with fishery products by targeting specific genes of Listeria monocytogenes, Salmonella, Shigella, Staphylococcus aureus, Streptococcus pyogenes, Vibrio cholerae, Vibrio parahaemolyticus, Vibrio vulnificus, and Yersinia enterocolitica and the 16S-23S rRNA gene internal transcribed spacer (ITS) region of Proteus mirabilis and Proteus vulgaris. The microarray contained 26 sp ...201121965411
The iron-responsive Fur/RyhB regulatory cascade modulates the Shigella outer membrane protease IcsP.Actin-based motility is central to the pathogenicity of the intracellular bacterial pathogen Shigella. Two Shigella outer membrane proteins, IcsA and IcsP, are required for efficient actin-based motility in the host cell cytoplasm, and the genes encoding both proteins are carried on the large virulence plasmid. IcsA triggers actin polymerization on the surface of the bacterium, leading to the formation of an actin tail that allows both intra- and intercellular spread. IcsP, an outer membrane pro ...201121859852
rates of mutation and host transmission for an escherichia coli clone over 3 years.although over 50 complete escherichia coli/shigella genome sequences are available, it is only for closely related strains, for example the o55:h7 and o157:h7 clones of e. coli, that we can assign differences to individual evolutionary events along specific lineages. here we sequence the genomes of 14 isolates of a uropathogenic e. coli clone that persisted for 3 years within a household, including a dog, causing a urinary tract infection (uti) in the dog after 2 years. the 20 mutations observed ...201122046404
polyclonal antibody against conserved sequences of mce1a protein blocks mtb infection in macrophages.the pathogenesis of mycobacterium tuberculosis is largely due to its ability to enter and survive within human macrophages. it is suggested that a specific protein namely mammalian cell entry protein is involved in the pathogenesis and the specific gene for this protein mce1a has been identified in several pathogenic organisms such as rickettsia, shigella, escherichia coli, helicobacter, streptomyces, klebsiella, vibrio, neisseria, rhodococcus, nocardioides, saccharopolyspora erthyrae, and pseud ...201122159737
long-term trends in the epidemiology and resistance of childhood bacterial enteropathogens in crete.in this study, we investigated the long-term trends in the epidemiology and susceptibility of bacterial enteropathogens among children in a well-defined area of adequate health standards. the study included all children younger than 14 years of age treated for enteritis at heraklion university general hospital on the island of crete during the 18-year period from january 1993 to december 2010. stool specimens were tested for salmonella, shigella, campylobacter, enteropathogenic escherichia coli ...201122207394
structuring the bacterial genome: y1-transposases associated with rep-bime sequences{dagger}reps are highly repeated intergenic palindromic sequences often clustered into structures called bimes including two individual reps separated by short linker of variable length. they play a variety of key roles in the cell. reps also resemble the sub-terminal hairpins of the atypical is200/605 family of insertion sequences which encode y1 transposases (tnpa(is200/is605)). these belong to the huh endonuclease family, carry a single catalytic tyrosine (y) and promote single strand transposition. ...201122199259
Antibiotics shaping bacterial genome: deletion of an IS91 flanked virulence determinant upon exposure to subinhibitory antibiotic concentrations.The nucleoid-associated proteins Hha and YdgT repress the expression of the toxin a-hemolysin. An Escherichia coli mutant lacking these proteins overexpresses the toxin a-hemolysin encoded in the multicopy recombinant plasmid pANN202-312R. Unexpectedly, we could observe that this mutant generated clones that no further produced hemolysin (Hly(-)). Generation of Hly(-) clones was dependent upon the presence in the culture medium of the antibiotic kanamycin (km), a marker of the hha allele (hha::T ...201122096603
a 35 kda antigenic protein from shigella flexneri: in silico structural and functional studies.shigella flexneri serotype 2a is a major public health concern in the developing and under-developed countries which contributes to shigellosis endemic and mortality. thus, there is an urgent need for a rapid diagnostic test for effective therapy and disease management. previous study showed that a ∼35 kda antigenic protein from s. flexneri is a potential biomarker. we therefore modelled the three-dimensional structure of the antigen to probe its functionality which could aid in the development ...201121982766
A gyrB-targeted PCR for rapid identification of Salmonella.Salmonella causes the majority of infections in humans and homeothermic animals. This article describes a specific polymerase chain reaction (PCR) method developed for a rapid identification of Salmonella. A gyrB-targeted species-specific primer pair, S-P-for (5'-GGT GGT TTC CGT AAA AGT A-3') and S-P-rev (5'-GAA TCG CCT GGT TCT TGC-3'), was successfully designed. PCR with all the Salmonella strains produced a 366- bp DNA fragment that was absent from all the non-Salmonella strains tested. The de ...201121892633
Exploration of in vitro time point quantitative evaluation of newly synthesized benzimidazole and benzothiazole derivatives as potential antibacterial agents.Present communication deals with the in vitro time point quantitative antibacterial evaluation of newly synthesized 1,2-disubstituted benzimidazoles (3a-p) and 2-substituted benzothiazoles (5a-h) against Gram-positive bacteria Staphylococcus aureus, Bacillus cereus, and Gram-negative bacteria Vibrio cholerae, Shigella dysenteriae and Escherichia coli. These compounds were synthesized under mild reaction conditions using Al(2)O(3)-Fe(2)O(3) nanocrystals as heterogeneous catalyst. Bio-evaluation s ...201122047695
emergence of ceftriaxone resistant shigella.shigellosis is endemic in many resource-poor countries due to feco-oral transmission, resulting in considerable morbidity and mortality. there is rapid emergence of multi-drug resistant (mdr) shigella spp. resulting in poor reliability of first line antibiotics like quinolones, co-trimoxazole and ampicillin. ceftriaxone has been used as a reserved antibiotic for treatment of mdr shigella spp. the authors report a case of ceftriaxone resistant shigella flexneri successfully managed with meropenem ...201122205379
Autophagy as an innate immunity paradigm: expanding the scope and repertoire of pattern recognition receptors.Autophagy is rapidly developing into a new immunological paradigm. The latest links now include overlaps between autophagy and innate immune signaling via TBK-1 and IKKa/ß, and the role of autophagy in inflammation directed by the inflammasome. Autophagy's innate immunity connections include responses to pathogen and damage-associated molecular patterns including alarmins such as HMGB1 and IL-1ß, Toll-like receptors, Nod-like receptors including NLRC4, NLRP3 and NLRP4, and RIG-I-like receptors. ...201122118953
Two Cases of Hemorrhagic Diarrhea Caused by Cronobacter sakazakii in Hospitalized Nursing Infants Associated with the Consumption of Powdered Infant Formula.Two cases of acute gastroenteritis occurred in 5-month-old infants hospitalized in a mother-and-child hospital in Queretaro, Mexico, on 24 January 2010. C. sakazakii was recovered from the powdered infant formula (PIF), rehydrated PIF (R-PIF) fed to infants, and their fecal samples. The microorganism was present at levels of 0.33 most probable number (MPN)/g and 24 MPN/ml in PIF and R-PIF, respectively. The total ingested dose for the day before the onset of the diarrheic syndrome ranged betwee ...201122186061
Investigation of the binding of a carbohydrate-mimetic peptide to its complementary anticarbohydrate antibody by STD-NMR spectroscopy and molecular-dynamics simulations.Saturation transfer difference (STD)-NMR spectroscopy was used to probe experimentally the bioactive solution conformation of the carbohydrate mimic MDWNMHAA 1 of the O-polysaccharide of Shigella flexneri Y when bound to its complementary antibody, mAb SYA/J6. Molecular dynamics simulations using the ZymeCAD™ Molecular Dynamics platform were also undertaken to give a more accurate picture of the conformational flexibility and the possibilities for bound ligand conformations. The ligand topology, ...201121953925
a proteogenomic analysis of shigella flexneri using 2d lc-maldi tof/tof.new strategies for high-throughput sequencing are constantly appearing, leading to a great increase in the number of completely sequenced genomes. unfortunately, computational genome annotation is out of step with this progress. thus, the accurate annotation of these genomes has become a bottleneck of knowledge acquisition.201122032405
emergence of a novel shiga toxin-producing escherichia coli o serogroup cross-reacting with shigella boydii type 10.this is the first report of the isolation of shiga toxin-producing escherichia coli (stec) strains whose o antigens were genetically and serologically identical to those of shigella boydii type 10, from human feces. the novel stec o serogroup may be widespread in japan and associated with diarrhea and hemorrhagic colitis.201121865424
contribution of the lipopolysaccharide to resistance of shigella flexneri 2a to extreme acidity.shigella flexneri is endemic in most underdeveloped countries, causing diarrheal disease and dysentery among young children. in order to reach its target site, the colon, shigella must overcome the acid environment of the stomach. shigella is able to persist in this stressful environment and, because of this ability it can initiate infection following the ingestion of very small inocula. thus, acid resistance is considered an important virulence trait of this bacterium. it has been reported that ...201121984920
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