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characterization of sulphonamide resistance genes and class 1 integron gene cassettes in enterobacteriaceae, central african republic (car).the aim of this study was to characterize genes encoding sulphonamide resistance and gene cassettes associated with class 1 integrons in trimethoprim-sulphamethoxazole resistant enterobacteriaceae recovered from bangui, central african republic (car).200717350987
[risk of hospitalisation due to foodborne bacterial gastroenteritis--secondary publication].in a matched cohort study we estimate the risk of hospitalisation due to gastroenteritis, complications and sequelae after infections with zoonotic salmonella, campylobacter spp., yersinia enterocolitica, e. coli and shigella infections. out of 52,783 patients, 7,524 (14.4%) were hospitalized with gastroenteritis, 647 (1.2%) with complications and 865 (1.7%) with long-term sequelae. in denmark in 2005 there were 6,010 registered episodes of infections with bacteria that are usually foodborne, co ...200717355849
campylobacter reactive arthritis: a systematic review.to review the literature on the epidemiology of campylobacter-associated reactive arthritis (rea).200717360026
shigella sonnei bacteremia: two adult cases and review of the literature.shigella sonnei bacteremia in adult patients is rare. we present 2 cases from our center, and 7 others from the literature are reviewed in detail. diabetes mellitus and malignancy are frequent predisposing conditions. despite severe illness at presentation, our patients achieved good outcomes with prompt initiation of antimicrobial therapy.200717366038
the type iii secretion system needle tip complex mediates host cell sensing and translocon insertion.type iii secretion systems (t3sss) are essential virulence determinants of many gram-negative bacterial pathogens. the shigella t3ss consists of a cytoplasmic bulb, a transmembrane region and a hollow 'needle' protruding from the bacterial surface. physical contact with host cells initiates secretion and leads to assembly of a pore, formed by ipab and ipac, in the host cell membrane, through which proteins that facilitate host cell invasion are translocated. as the needle is implicated in host c ...200717367391
elimination by ozone of shigella sonnei in shredded lettuce and water.several outbreaks of shigellosis have been attributed to the consumption of contaminated fresh-cut vegetables. the minimal processing of these products make it difficult to ensure that fresh produce is safe for consumer. chlorine-based agents have been often used to sanitize produce and reduce microbial populations in water applied during processing operations. however, the limited efficacy of chlorine-based agents and the production of chlorinated organic compounds with potential carcinogenic a ...200717367682
low molecular weight proteins of outer membrane of salmonella typhimurium are immunogenic in salmonella induced reactive arthritis revealed by proteomics.in patients with reactive arthritis (rea)/undifferentiated spondyloarthropathy (uspa), synovial fluid mononuclear cells (sfmc) show proliferation to bacterial antigens that trigger rea, i.e. chlamydia, yersinia, campylobactor, shigella and salmonella species. we have shown previously that sfmc proliferate significantly to outer membrane proteins of s typhimurium in salmonella induced rea. in the present study we characterized the immunoreactive fractions of outer membrane protein (omp) of s typh ...200717376200
inactivation of foodborne pathogens using a one atmosphere uniform glow discharge plasma.this study was conducted to determine the efficacy of a one atmosphere uniform glow discharge plasma (oaugdp) for inactivation of foodborne pathogens and to evaluate the influence of growth temperature, ph, and culture age on their inactivation. escherichia coli o157:h7, listeria monocytogenes, staphylococcus aureus, bacillus cereus, salmonella enteritidis, vibrio parahaemolyticus, yersinia enterocolitica, and shigella flexneri were evaluated. three-strain mixtures of each bacterium were inocula ...200717378708
antimicrobial activity of bacillus subtilis and bacillus pumilus during the fermentation of african locust bean (parkia biglobosa) for soumbala production.to examine predominant isolates of bacillus subtilis and b. pumilus isolated from soumbala for their antimicrobial activity against indicator microorganisms as micrococcus luteus, staphyloccocus aureus, bacillus cereus, enterococus facium, listeria monocytogenes, escherichia coli, salmonella typhimurium, shigella dysenteriae, yersinia enterocolitica, aspergillus ochraceus and penicillium roqueforti.200717381739
l-sorbose utilization by virulent escherichia coli and shigella: different metabolic adaptation of pathotypes.the frequency of l-sorbose utilization differs significantly between pathotypes of escherichia coli and shigella from 93% to 0%. among 266 strains tested, this frequency increased in the order shigella, enterotoxigenic e. coli (etec), enteroinvasive e. coli (eiec), shiga toxin-producing e. coli (stec), enteroaggregative e. coli, enteropathogenic e. coli (epec), and neonatal bacterial meningitis (nbm) e. coli. this suggests an association of pathomechanism with the capability to degrade l-sorbose ...200717382590
in vitro activity of garenoxacin tested against a worldwide collection of ciprofloxacin-susceptible and ciprofloxacin-resistant enterobacteriaceae strains (1999-2004).garenoxacin is a novel des-f(6)-quinolone with a chemical structure that lacks the c6 position fluorine and has a unique difluoromethoxy substitution at position c8. this study evaluated the in vitro activity of garenoxacin tested against a large collection of enterobacteriaceae collected worldwide. the bacterial isolates were consecutively collected from more than 70 medical centers from bloodstream, respiratory, urinary tract, and skin and soft tissue infections. the isolates were tested again ...200717383140
small rnas controlling iron metabolism.iron is one of the most important metals in the metabolism of many organisms, including bacteria, in which it serves as a cofactor in multiple enzymatic reactions. most of the earlier research on iron regulation in bacteria has focused on the transcriptional regulator fur and its effect on the many genes involved in iron uptake. more recent work demonstrates the essential role of a small regulatory rna, ryhb, in iron metabolism. ryhb downregulates a large number of transcripts encoding iron-usin ...200717383226
assessment and interpretation of bacterial viability by using the live/dead baclight kit in combination with flow cytometry.the commercially available live/dead baclight kit is enjoying increased popularity among researchers in various fields of microbiology. its use in combination with flow cytometry brought up new questions about how to interpret live/dead staining results. intermediate states, normally difficult to detect with epifluorescence microscopy, are a common phenomenon when the assay is used in flow cytometry and still lack rationale. it is shown here that the application of propidium iodide in combinatio ...200717384309
[molecular characterization of the strain causing a shigellosis outbreak in a madrid school].the aim of this study is to describe a shigella sonnei outbreak in a school.200717386220
characterization of the outer membrane receptor shua from the heme uptake system of shigella dysenteriae. substrate specificity and identification of the heme protein ligands.shigella dysenteriae, like many bacterial pathogens, has evolved outer membrane receptor-mediated pathways for the uptake and utilization of heme as an iron source. as a first step toward understanding the mechanism of heme uptake we have undertaken a site-directed mutagenesis, spectroscopic, and kinetic analysis of the outer membrane receptor shua of s. dysenteriae. purification of the outer membrane receptor gave a single band of molecular mass 73 kda on sds-page. initial spectroscopic analysi ...200717387178
detecting low concentrations of shigella sonnei in environmental water samples by pcr.outbreaks of shigella sonnei associated with contaminated water have been reported and methods for the simultaneous detection of shigellae and enteroinvasive escherichia coli in water samples have been developed with detection limits of 10(1)-10(2) cfu ml(-1) of water. because 10(1)-10(2)shigellae can cause disease, a more sensitive detection method as an addition to the existing methods for detection of shigella sonnei in water samples is reported here. initially, 33 shigella sonnei and 72 non- ...200717391373
vitamin a deficiency in patients with diarrhea and hiv infection in ethiopia.diarrhea, micronutrient deficiencies and hiv/aids are major public health problems in developing countries, especially in sub-saharan africa. this study was aimed to investigate serum levels of vitamin a in diarrheic patients with and without hiv co-infection compared to healthy controls. two hundred eleven diarrheic patients (110 hiv infected), 87 apparently healthy controls and 41 asymptomatic hiv seropositive blood donors who visited the university of gondar hospital, in gondar, ethiopia were ...200717392128
[current status of multi-drug resistant bacteria in infectious diarrheal diseases and its control]. 200717455674
ubiquitin trafficking to the lysosome: keeping the house tidy and getting rid of unwanted guests.bacterial killing by autophagic delivery to the lysosomal compartment has been shown for mycobacteria, streptococcus, shigella, legionella and salmonella, indicating an important role for this conserved trafficking pathway for the control of intracellular bacterial pathogens.(1-5) in a recent study we found that solubilized lysosomes isolated from bone marrow-derived macrophages had potent antibacterial properties against m. tuberculosis and m. smegmatis that were associated with ubiquitin and u ...200717457035
erythema nodosum associated with shigella colitis in a 7-year-old boy. 200717459754
sensitivity of escherichia albertii, a potential food-borne pathogen, to food preservation treatments.escherichia albertii is a potential food-borne pathogen because of its documented ability to cause diarrheal disease by producing attachment and effacement lesions. its tolerances to heat (56 degrees c), acid (ph 3.0), and pressure (500 mpa [5 min]) were evaluated and found to be significantly less than those of wild-type e. coli o157:h7.200717468283
rotavirus mortality confirmed by etiologic identification in venezuelan children with diarrhea.hospital-based studies to determine the etiology of deaths from diarrhea are scarce. in this study, we specifically analyzed deaths due to rotavirus to assess the rotavirus impact on diarrhea mortality.200717468648
effects of heating, storage, and ultraviolet exposure on antimicrobial activity of garlic juice.this study was designed to investigate the effect of heating, storage, and ultraviolet exposure on antimicrobial activity of garlic juice and its bacteriocidal activity against common human pathogens. antimicrobial activity of fresh garlic juice was tested against escherichia coli, staphylococcus aureus, streptococcus hemolyticus b, s. hemolyticus a, klebsiella sp., shigella dysenteriae, and candida albicans using the disc method. the dilution method was performed by addition of garlic juice to ...200717472490
protective role of lactobacilli in shigella dysenteriae 1-induced diarrhea in rats.studies on lactic acid bacteria exemplify their use against various enteropathogens in vitro. nevertheless, in vivo effects of lactobacillus during shigella infection have not been evaluated. the present study evaluated the effect of lactobacillus rhamnosus and lactobacillus acidophilus on neutrophil infiltration and lipid peroxidation during shigella dysenteriae 1-induced diarrhea in rats.200717483010
mutations in the gyra subunit of dna gyrase and the parc subunit of topoisomerase iv in clinical strains of fluoroquinolone-resistant shigella in anhui, china.in this research 26 shigella isolates were examined by pcr and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (qrdrs). we tested for the presence of qnr genes by pcr in 91 strains, but no qnr genes were found. the results did show, however, some novel mutations at codon 83 of gyra (ser-->ile) and codon 64 of parc (ala64-->cys, ala64-->asp), which were related to fluroquinolone resistance.200717483803
[pfge of shigella flexneri 4c isolates from food-poisoning outbreaks and sporadic diarrhea patients].to know the molecular characteristic of shigella flexneri 4c isolates from patients in two food-poisoning outbreaks and one sporadic diarrhea case in hangzhou, china.200717484212
[analysis about epidemic situation of dysentery near upon fourteen years in beijing].to realize the epidemiological and drug-resistance characteristics of dysentery during 1990 to 2003 in beijing.200717484213
[bacillary dysentery shigellosis]. 200717491367
survival of shigella sonnei on smooth tomato surfaces, in potato salad and in raw ground beef.this study investigated the survival of a five-strain shigella sonnei cocktail on smooth tomato surfaces, in potato salad and in raw ground beef. all inocula were resistant to the antibiotic rifampicin to allow simple detection of the target culture among the indigenous microflora of the food samples. inoculated tomatoes were stored at 13 degrees c/85% relative humidity, the standard holding conditions for mature, green tomatoes. inoculated potato salad and ground beef samples were stored at 2.5 ...200717428565
preliminary foodnet data on the incidence of infection with pathogens transmitted commonly through food--10 states, 2006.foodborne illnesses are a substantial health burden in the united states. the foodborne diseases active surveillance network (foodnet) of cdc's emerging infections program collects data from 10 u.s. states regarding diseases caused by enteric pathogens transmitted commonly through food. foodnet quantifies and monitors the incidence of these infections by conducting active, population-based surveillance for laboratory-confirmed illnesses. this report describes preliminary surveillance data for 20 ...200717431379
plasmid-mediated quinolone resistance determinant qnrs1 found in salmonella enterica strains isolated in the uk.to determine the prevalence of qnr genes in selected salmonella enterica and escherichia coli isolated in the uk.200717434878
ryhb, an iron-responsive small rna molecule, regulates shigella dysenteriae virulence.regulation of bacterial gene expression by small rna (srna) molecules is an increasingly recognized phenomenon but one that is not yet fully understood. we show that the srna ryhb suppresses several virulence-associated phenotypes of shigella dysenteriae, a causative agent of bacillary dysentery in humans. the virulence genes repressed by s. dysenteriae ryhb include those encoding the type iii secretion apparatus, its secreted effectors, and specific chaperones. suppression of shigella virulence ...200717438026
dipstick for rapid diagnosis of shigella flexneri 2a in stool.shigellosis or bacillary dysentery, an acute bloody diarrhoea, is a major public health burden in developing countries. in the absence of prompt and appropriate treatment, the infection is often fatal, particularly in young malnourished children. here, we describe a new diagnostic test for rapid detection, in stool, at the bedside of patients, of shigella flexneri 2a, the most predominant agent of the endemic form of the disease.200717440606
a novel serovar of shigella dysenteriae from patients with diarrhoea in bangladesh.every year, around 3 % of isolates from patients with diarrhoea at dhaka hospital, icddr,b, are identified as shigella-like organisms (slos) based on their activity in biochemical tests. these isolates do not react with any of the current shigella antisera including all existing and provisional serotypes. among these slos, a unique cluster of seven isolates with an identical plasmid profile was found and these isolates were further characterized by phenotypic and genotypic techniques. all were n ...200717446289
effect of intensive handwashing in the prevention of diarrhoeal illness among patients with aids: a randomized controlled study.patients with aids frequently develop diarrhoeal illness. in this randomized, controlled study, 260 patients were screened for those who had not had diarrhoea in the preceding 3 months and who had received a stable highly active antiretroviral therapy regimen for at least 6 weeks prior to the study enrollment. a total of 148 patients met the inclusion criteria and were enrolled: 75 patients were randomly assigned to an intensive handwashing intervention (i.e. handwashing after defecation, after ...200717446290
rapid engineering of bacterial reporter gene fusions by using red recombination.reporter gene fusions are essential tools for the investigation of gene regulation. such fusions are traditionally generated by transposon mutagenesis and identified by a suitable selection procedure. alternatively, specific reporter fusions can be generated by cloning of dna fragments containing promoters or other regulatory elements in reporter plasmids. here, we describe a novel approach for the rapid generation of reporter gene fusions in single copies at defined positions in bacterial genom ...200717513596
[mathematical modeling and prognosis of incidence of enteric anthroponoses with aqueous route of transmission].using data on long-term dynamics of epidemic process of acute enteric infections enteric with aqueous route of transmission (typhoid fever, shigellosis caused by shigella flexneri, hepatitis a, rotavirus gastroenteritis, etc.)the equation of regression was developed with the help of chebyshev's polynoms. predicted incidences of these infections for 2005 were on 61.2-99.5% in agree with the real ones on two territories of north region of west siberia. predicted incidence for 2006 is reflecting te ...200717523473
[shigellosis in karachaevo-cherkes republic in 1996-2005].incidence and etiologic structure of shigellosis in karachaevo-cherkes republic for 10 years are analyzed and compared with same characteristics in russia overall. sharp rise of shigellosis cases number is detected in 2003-2005 as well as predominance of shigella sonnei represented by biovar ilg. it was shown that shigella strains with different resistance to tetracycline and chloramphenicol circulate in karachaevo-cherkes republic.200717523488
crystal structures of trna-guanine transglycosylase (tgt) in complex with novel and potent inhibitors unravel pronounced induced-fit adaptations and suggest dimer formation upon substrate binding.the bacterial trna-guanine transglycosylase (tgt) is a trna modifying enzyme catalyzing the exchange of guanine 34 by the modified base preq1. the enzyme is involved in the infection pathway of shigella, causing bacterial dysentery. as no crystal structure of the shigella enzyme is available the homologous zymomonas mobilis tgt was used for structure-based drug design resulting in new, potent, lin-benzoguanine-based inhibitors. thorough kinetic studies show size-dependent inhibition of these com ...200717524419
icsa surface presentation in shigella flexneri requires the periplasmic chaperones degp, skp, and sura.a shigella flexneri degp mutant, which was defective for plaque formation in henle cell monolayers, had a reduced amount of icsa detectable on the bacterial surface with antibody. however, the mutant secreted icsa to the outer membrane at wild-type levels. this suggests that icsa adopts an altered conformation in the outer membrane of the degp mutant with reduced exposure on the cell surface. icsa is, therefore, unlikely to be accessible to actin-nucleating proteins within the eukaryotic cell cy ...200717526712
plasmids derived from gifsy-1/gifsy-2, lambdoid prophages contributing to the virulence of salmonella enterica serovar typhimurium: implications for the evolution of replication initiation proteins of lambdoid phages and enterobacteria.gifsy-1 and gifsy-2 are lambdoid prophages which contribute to the virulence of salmonella enterica serovar typhimurium. the nucleotide sequence of the replication region of both prophages is identical, and similar in organization to the replication region of bacteriophage lambda. to investigate the replication of the gifsy phages and the relationship between gifsy and host chromosome replication, a plasmid which contained all the genes and regulatory sequences required for autonomous replicatio ...200717526845
a comparative assessment of the antimicrobial effects of garlic (allium sativum) and antibiotics on diarrheagenic organisms.antimicrobial sensitivity tests were carried out on escherichia coli, shigella sp, salmonella sp, and proteus mirabilis using standard procedures. significant differences (p < 0.01) were seen in the effect of the antimicrobial agents (garlic, ciprofloxacin and ampicillin), and in the sensitivities of the microbial species (p < 0.01) to the antimicrobial agents were observed. the gram-negative diarrheagenic pathogens from the stool samples were highly sensitive to garlic, while ciprofloxacin (cpx ...200717539285
[using neosmectin in the complex therapy of patients with acute intestinal infections]. 200717539357
different probiotic properties for lactobacillus fermentum strains isolated from swine and poultry.systematic procedures were used to evaluate the probiotic properties of lactobacillus fermentum (l. fermentum) strains isolated from swine and poultry. the major properties included their capabilities to adhere to the intestinal epithelium of swine and poultry, the inhibition on pathogenic bacteria, and their tolerance to the gastric juice and bile salts. results showed that l. fermentum strains from poultry digestive tract showed better adherence to the swine intestine and chicken crop epitheli ...200717544731
control and regulation of kple1 prophage site-specific recombination: a new recombination module analyzed.kple1 is one of the 10 prophage regions of escherichia coli k12, located at 2464 kb on the chromosome. kple1 is defective for lysis, but it is fully competent for excisive recombination. in this study, we have mapped the binding sites of the recombination proteins, namely ints, tori, and ihf on attl and attr, and the organization of these sites suggests that the intasome is architecturally different from the lambda canonical form. we also measured the relative contribution of these proteins to b ...200717545146
genetic flux over time in the salmonella lineage.dna sequences that are shared between closely related organisms while being absent from their common ancestor and from sister lineages of that ancestor are likely to have been acquired by horizontal gene transfer. over time, the composition of those sequences tends to become more similar to the compositional signature of their host (amelioration).200717547764
ctx-m extended-spectrum beta-lactamases, washington state. 200717552121
emergence of shiga toxin 1 genes within shigella dysenteriae type 4 isolates from travelers returning from the island of hispañola.shiga toxins are produced by shigella dysenteriae type 1 and certain strains of escherichia coli. three cases of shiga toxin-producing s. dysenteriae type 4 were identified among travelers to the island of hispañola between 2002 and 2005. clinical and public health practitioners should be aware of this newly identified strain.200717556630
clinical trials of shigella vaccines: two steps forward and one step back on a long, hard road.more than 50 years of research has yielded numerous shigella vaccine candidates that have exemplified both the promise of vaccine-induced prevention of shigellosis and the impediments to developing a safe and effective vaccine for widespread use, a goal that has yet to be attained. this review discusses the most advanced strategies for shigella vaccine development, the immune responses that are elicited following disease or vaccination, the factors that have accelerated or impeded shigella vacci ...200717558427
screening methods used to determine the anti-microbial properties of aloe vera inner gel.the emergence of antibiotic resistant bacterial strains is a growing problem and is an important concern for patients, physicians, healthcare managers, and policymakers as it results in poorer health and economic outcomes. this has led to an urgent global call for new antimicrobial drugs, particularly from natural resources. we have been studying the antimicrobial properties of the inner leaf gel component of aloe barbadensis miller and have used a number of different, simple in vitro assays to ...200717560318
the inner gel component of aloe vera suppresses bacterial-induced pro-inflammatory cytokines from human immune cells.the present study was carried out to examine the anti-inflammatory activity of the inner leaf gel component of aloe barbadensis miller. a simple in vitro assay was designed to determine the effect of the inner gel on bacterial-induced pro-inflammatory cytokine production, namely tnf-alpha and il-1 beta, from peripheral blood leukocytes stimulated with shigella flexneri or lps. this report describes the suppression of both cytokines with a freeze-dried inner gel powder and a commercial health dri ...200717560326
novel extended-spectrum beta-lactamase in shigella sonnei. 200717561568
antimicrobial activity of a series of thiosemicarbazones and their zn(ii) and pd(ii) complexes.thirty-four thiosemicarbazones and s-alkyl thiosemicarbazones, and some of their zn(ii) and pd(ii) complexes were obtained and purified to investigate antimicrobial activity. mic values of the compounds were determined by the disc diffusion method against escherichia coli, klebsiella pneumoniae, proteus mirabilis, pseudomonas aeruginosa, salmonella typhi, shigella flexneri, staphylococcus aureus, s. epidermidis, and candida albicans. the thiosemicarbazones show antibacterial and antifungal effec ...200717571790
preparation and characterization of translocator/chaperone complexes and their component proteins from shigella flexneri.shigella flexneri causes a severe form of bacillary dysentery also known as shigellosis. onset of shigellosis requires bacterial invasion of colonic epithelial cells which is initiated by the delivery of translocator and effector proteins to the host cell membrane and cytoplasm, respectively, by the shigella type iii secretion system (ttss). the shigella translocator proteins, ipab and ipac, form a pore complex in the host cell membrane to facilitate effector delivery; however, prior to their se ...200717571858
dna sequencing of a pathogenicity-related plasmid of an avian septicemic escherichia coli strain.a 43-mda conjugative plasmid isolated from an avian septicemic escherichia coli (apec) strain possessing genes related to the adhesion and invasion capacities of in vitro-cultured cells was sequenced. the results demonstrated that the 43-mda plasmid harbors bacterial pathogenicity-related sequences which probably allow the wild-type pathogenic strain to adhere to and invade tissues and to cause septicemia in poultry. the existence of homology sequences to sequences belonging to other human patho ...200717573664
serotyping, pcr, phage-typing and antibiotic sensitivity testing of salmonella serovars isolated from urban drinking water supply systems of nepal.to study the occurrence and diversity of salmonella serovars in urban water supply systems of nepal.200717576218
norovirus outbreak in a district general hospital--new strain identified.media reports about norovirus outbreaks, especially in hospitals and nursing homes, have accumulated in the past years. the reasons for this increasing problem are manifold: resistance against common disinfectants, a high level of contagion (a dose of less than 100 particles may be infective); variability of the virus-genome documented by polymerase chain reaction-studies, as well as further factors concerning modern life-style. the following study describes and analyses a norovirus outbreak in ...200717299671
evaluation of an enzyme immunoassay-based stool antigen test to detect campylobacter jejuni and campylobacter coli.an enzyme immunoassay-based antigen test (ridascreen campylobacter; r-biopharm, darmstadt, germany) was evaluated for the detection of campylobacter jejuni and campylobacter coli in 1050 clinical stool samples as compared with culture on selective medium. after routine inoculation for salmonella, shigella, yersinia, aeromonas, plesiomonas, and campylobacter, the same swab specimens were used for the antigen test. the positivity rate for campylobacter was 9.3% in culture, and the antigen test gav ...200717300899
the phosphothreonine lyase activity of a bacterial type iii effector family.pathogenic bacteria use the type iii secretion system to deliver effector proteins into host cells to modulate the host signaling pathways. in this study, the shigella type iii effector ospf was shown to inactivate mitogen-activated protein kinases (mapks) [extracellular signal-regulated kinases 1 and 2 (erk1/2), c-jun n-terminal kinase, and p38]. ospf irreversibly removed phosphate groups from the phosphothreonine but not from the phosphotyrosine residue in the activation loop of mapks. mass sp ...200717303758
yeast functional genomic screens lead to identification of a role for a bacterial effector in innate immunity regulation.numerous bacterial pathogens manipulate host cell processes to promote infection and ultimately cause disease through the action of proteins that they directly inject into host cells. identification of the targets and molecular mechanisms of action used by these bacterial effector proteins is critical to understanding pathogenesis. we have developed a systems biological approach using the yeast saccharomyces cerevisiae that can expedite the identification of cellular processes targeted by bacter ...200717305427
the role of the vacb gene in the pathogenesis of brucella abortus.brucella species are important zoonotic pathogens affecting a wide variety of mammals. therefore, the identification of new brucella virulence factors is of great interest in understanding bacterial pathogenesis and immune evasion. in this study, we have identified brucella abortus vacb gene that presents 2343 nucleotides and 781 amino acids and it shows 39% identity with shigella flexneri vacb gene that encodes an exoribonuclease rnase r involved in bacterial virulence. further, we have inactiv ...200717306588
h-ns antagonism in shigella flexneri by virb, a virulence gene transcription regulator that is closely related to plasmid partition factors.the virb protein of shigella flexneri is a positive regulator of the major virulence operons of this enteroinvasive intracellular pathogen. virb resembles no other transcription factor but is strongly homologous to plasmid partition proteins. we found that the binding of the virb protein to the promoter region of the icsb virulence gene induced hypersensitivity to cleavage by dnase i over a region to which the h-ns repressor protein binds and completely abolished the protection of this sequence ...200717307842
heme inhibits the dna binding properties of the cytoplasmic heme binding protein of shigella dysenteriae (shus).heme uptake and utilization by pathogenic bacteria are critical for virulence and disease, since heme and heme proteins are a major source of iron within the host. although the role of outer membrane heme receptors in this process has been extensively characterized at the genetic and biochemical level, the role of the cytoplasmic heme binding proteins is not yet clear. the shigella dysenteriae cytoplasmic heme binding protein, shus, has previously been shown to promote utilization of heme as an ...200717323920
conformational stability and differential structural analysis of lcrv, pcrv, bipd, and sipd from type iii secretion systems.diverse gram-negative bacteria use type iii secretion systems (t3ss) to translocate effector proteins into the cytoplasm of eukaryotic cells. the type iii secretion apparatus (t3sa) consists of a basal body spanning both bacterial membranes and an external needle. a sensor protein lies at the needle tip to detect environmental signals that trigger type iii secretion. the shigella flexneri t3sa needle tip protein, invasion plasmid antigen d (ipad), possesses two independently folding domains in v ...200717327391
a method for fast and simple detection of major diarrhoeagenic escherichia coli in the routine diagnostic laboratory.a multiplex pcr was developed for the detection of the following genes characteristic of diarrhoeagenic escherichia coli (dec): verocytotoxins 1 (vtx1) and 2 (vtx2), characteristic of verocytotoxin-producing e. coli (vtec); intimin (eae), found in enteropathogenic e. coli (epec), attaching and effacing e. coli and vtec; heat-stable enterotoxin (esta) and heat-labile enterotoxin (elta), characteristic of enterotoxigenic e. coli (etec); and invasive plasmid antigen (ipah), characteristic of entero ...200717331124
extended-spectrum beta-lactamase-producing shigella strains in israel, 2000-2004.routine susceptibility testing of 5,616 shigella isolates at the national shigella reference centre in israel over a 5-year period (2000-2004) revealed resistance to ceftriaxone in one strain of shigella boydii 2 and in two strains each of shigella flexneri 2a, s. flexneri 6, and shigella sonnei. all seven isolates were confirmed as producers of extended-spectrum beta-lactamase (esbl) by the combination disk method, the vitek 1 system, and a modification of the double-disk synergy test, which is ...200717265070
epidemiological characterization of resistance and pcr typing of shigella flexneri and shigella sonnei strains isolated from bacillary dysentery cases in southeast brazil.shigella spp are gram-negative, anaerobic facultative, non-motile, and non-sporulated bacilli of the enterobacteriaceae family responsible for "shigellosis" or bacillary dysentery, an important cause of worldwide morbidity and mortality. however, despite this, there are very few epidemiological studies about this bacterium in brazil. we studied the antibiotic resistance profiles and the clonal structure of 60 shigella strains (30 s. flexneri and 30 s. sonnei) isolated from shigellosis cases in d ...200717273662
evaluation of the growth inhibitory activities of triphala against common bacterial isolates from hiv infected patients.the isolation of microbial agents less susceptible to regular antibiotics and the rising trend in the recovery rates of resistant bacteria highlights the need for newer alternative principles. triphala has been used in traditional medicine practice against certain diseases such as jaundice, fever, cough, eye diseases etc. in the present study phytochemical (phenolic, flavonoid and carotenoid) and antibacterial activities of aqueous and ethanol extracts of triphala and its individual components ( ...200717273983
new animal model of shigellosis in the guinea pig: its usefulness for protective efficacy studies.it has been difficult to evaluate the protective efficacy of vaccine candidates against shigellosis, a major form of bacillary dysentery caused by shigella spp. infection, because of the lack of suitable animal models. to develop a proper animal model representing human bacillary dysentery, guinea pigs were challenged with virulent shigella flexneri serotype 2a (strains 2457t or ysh6000) or s. flexneri 5a (strain m90t) by the intrarectal (i.r.) route. interestingly, all guinea pigs administered ...200717277155
bioluminescent signal system: bioluminescence immunoassay of pathogenic organisms.the ca(2+)-regulated photoprotein obelin has been examined as a label for bioluminescence immunoassay of infective agents. the hepatitis b virus (hbsag) and the bacteria escherichia coli and shigella sonnei lipopolysaccharide (lps) were chosen as model antigens. chemically synthesized obelin-corresponding antibody conjugates were used in a solid-phase microplate immunoassay. the sensitivities achieved by the assay were 0.25 ng/ml for s. sonnei lps and 0.375 ng/ml for hbsag. a novel, filter-based ...200717286244
gene expression profiling of the ph response in shigella flexneri 2a.the ph response of shigella flexneri 2a 301 was identified by gene expression profiling. gene expression profiles of cells grown in ph 4.5 or 8.6 were compared with the profiles of cells grown at ph 7.0. differential expression was observed for 307 genes: 97 were acid up-regulated, 102 were acid down-regulated, 91 were base up-regulated, and 86 were base down-regulated. twenty-seven genes were found to be both acid and base up-regulated, and 29 genes were both acid and base down-regulated. this ...200717286558
o-specific [corrected] polysaccharide conjugate vaccine-induced [corrected] antibodies prevent invasion of shigella into caco-2 cells and may be curative.the o-specific polysaccharide (o-sp) domain of shigella lps is both an essential virulence factor and a protective antigen for this genus. a critical level of serum igg anti-o-sp was shown to confer immunity to shigellosis, likely by complement-mediated bacteriolysis of the inoculum. conjugate shigella o-sp vaccines were shown to be safe and immunogenic in children, and, in a preliminary study, shigella sonnei vaccine was protective in young adults. characteristic of shigellosis is bacterial inv ...200717287349
capping of actin filaments by vinculin activated by the shigella ipaa carboxyl-terminal domain.shigella, the causative agent of bacillary dysentery, invades epithelial cells. upon bacterial-cell contact, the type iii bacterial effector ipaa binds to the cytoskeletal protein vinculin to promote actin reorganization required for efficient bacterial uptake. we show that the last 74 c-terminal residues of ipaa (a559) bind to human vinculin (hv) and promotes its association with actin filaments. polymerisation experiments demonstrated that a559 was sufficient to induce hv-dependent partial cap ...200717289036
seasonality in six enterically transmitted diseases and ambient temperature.we propose an analytical and conceptual framework for a systematic and comprehensive assessment of disease seasonality to detect changes and to quantify and compare temporal patterns. to demonstrate the proposed technique, we examined seasonal patterns of six enterically transmitted reportable diseases (eds) in massachusetts collected over a 10-year period (1992-2001). we quantified the timing and intensity of seasonal peaks of ed incidence and examined the synchronization in timing of these pea ...200717291363
study of polymorphic variable-number of tandem repeats loci in the ecor collection and in a set of pathogenic escherichia coli and shigella isolates for use in a genotyping assay.the escherichia coli (e. coli) reference collection, ecor, consists of 72 strains that are representative of the genotypic diversity, as indexed by multilocus enzyme electrophoresis (mlee), in the species as a whole. mlee revealed 4 main phylogenetic groups designated a, b1, b2 and d. we present a study of the relationship between the ecor strains as determined by polymorphisms in seven variable-number of tandem repeats (vntr) loci. seven tandem repeats that were present in more than one of the ...200717291612
case-control study of shigellosis in san francisco: the role of sexual transmission and hiv infection.shigella species infect approximately 450,000 persons annually in the united states. person-to-person transmission of shigella species, which have a low infectious dose, occurs frequently, particularly in areas with poor sanitation and hygiene. sexual transmission of shigella species among men who have sex with men (msm) has been inferred from outbreaks of shigellosis among that population, and limited studies have suggested the importance of human immunodeficiency virus (hiv) infection as a ris ...200717205436
another perfect storm: shigella, men who have sex with men, and hiv. 200717205437
use of linear, weibull, and log-logistic functions to model pressure inactivation of seven foodborne pathogens in milk.survival curves of six foodborne pathogens suspended in ultra high-temperature (uht) whole milk and exposed to high hydrostatic pressure at 21.5 degrees c were obtained. vibrio parahaemolyticus was treated at 300 mpa and other pathogens, listeria monocytogenes, escherichia coli o157:h7, salmonella enterica serovar enteritidis, salmonella enterica serovar typhimurium, and staphylococcus aureus were treated at 600 mpa. all the survival curves showed a rapid initial drop in bacterial counts followe ...200717188197
polar positional information in escherichia coli spherical cells.shigella surface protein icsa and its cytoplasmic derivatives are localized to the old pole of rod-shaped cells when expressed in escherichia coli. in spherical mreb cells, icsa is targeted to ectopic sites and close to one extremity of actin-like mamk filament. to gain insight into the properties of the sites containing polar material, we studied the icsa localization in spherical cells. gfp was exported into the periplasm via the tat pathway and used as a periplasmic space marker. gfp displaye ...200717188233
shigella's ways of manipulating the host intestinal innate and adaptive immune system: a tool box for survival?shigella, a gram-negative invasive enteropathogenic bacterium, causes the rupture, invasion and inflammatory destruction of the human colonic epithelium. this complex and aggressive process accounts for the symptoms of bacillary dysentery. the so-called invasive phenotype of shigella is linked to expression of a type iii secretory system (ttss) injecting effector proteins into the epithelial cell membrane and cytoplasm, thereby inducing local but massive changes in the cell cytoskeleton that lea ...200717213832
shigella chromosomal ipah proteins are secreted via the type iii secretion system and act as effectors.shigella possess 220 kb plasmid, and the major virulence determinants, called effectors, and the type iii secretion system (ttss) are exclusively encoded by the plasmid. the genome sequences of s. flexneri strains indicate that several ipah family genes are located on both the plasmid and the chromosome, but whether their chromosomal ipah cognates can be secreted from shigella remains unknown. here we report that s. flexneri strain, ysh6000 encodes seven ipah cognate genes on the chromosome and ...200717214743
an h-ns-like stealth protein aids horizontal dna transmission in bacteria.the sfh protein is encoded by self-transmissible plasmids involved in human typhoid and is closely related to the global regulator h-ns. we have found that sfh provides a stealth function that allows the plasmids to be transmitted to new bacterial hosts with minimal effects on their fitness. introducing the plasmid without the sfh gene imposes a mild h-ns(-) phenotype and a severe loss of fitness due to titration of the cellular pool of h-ns by the a+t-rich plasmid. this stealth strategy seems t ...200717218529
erosion of interaction networks in reduced and degraded genomes.unlike eukaryotes, which often recruit duplicated genes into existing protein-protein interaction (ppi) networks, the low levels of gene duplication coupled with the high probability of lateral transfer of novel genes alters the manner in which ppi networks can evolve in bacteria. by inferring the ppis present in the ancestor to contemporary gammaproteobacteria, we were able to trace the changes in gene repertoires, and their consequences on ppi network evolution, in several bacterial lineages t ...200717219366
analysis of strategies to successfully vaccinate infants in developing countries against enterotoxigenic e. coli (etec) disease.enterotoxigenic escherichia coli (etec) is the most common bacterial cause of diarrhoea in the world, annually affecting up to 400,000,000 children under 5 years of age living in developing countries (dcs). although etec possesses numerous antigens, the relatively conserved colonization factor (cf) antigens and the heat labile enterotoxin (lt) have been associated with protection and most vaccine candidates have exploited these antigens. a safe and effective vaccine against etec is a feasible go ...200717224212
antibacterial activity and in vitro anti-tumor activity of the extract of the larvae of the housefly (musca domestica).one of the significant characteristics of traditional chinese medicine is the use of insects, other terrestrial arthropods and their products as drugs. in the present work, the extract of housefly (musca domestica) larvae was studied by an agar well diffusion assay and minimum bactericidal concentration (mbc) determination for detection of antimicrobial activity and by mtt assay method to test its in vitro anti-tumor activity. in our studies, the extract inhibited six tested bacterial pathogens ...200717227700
immunogenicity and characterization of wrsf2g11: a second generation live attenuated shigella flexneri 2a vaccine strain.recent clinical trials involving live attenuated shigella vaccine strains sc602 and wrss1 have revealed that deletion of the virg(icsa) gene dramatically reduces virulence in human volunteers. these strains can be given at low oral doses and induce a strong, and in some cases, protective immune responses. however, residual vaccine associated reactogenicity suggests that further attenuation is required. a recent clinical trial indicated that the set and sen enterotoxin genes contribute to the sym ...200717229494
role of infection in irritable bowel syndrome.infection by pathogenic organisms leads to mucosal damage and disruption of the gut's extensive commensal flora, factors which may lead to prolonged bowel dysfunction. six to 17% of unselected irritable bowel syndrome (ibs) patients believe their symptoms began with an infection, which is supported by prospective studies showing a 4%-31% incidence of postinfectious ibs-(pi) following bacterial gastroenteritis. the wide range of incidence can be accounted for by differences in risk factors, which ...200717238025
using european travellers as an early alert to detect emerging pathogens in countries with limited laboratory resources.the volume, extent and speed of travel have dramatically increased in the past decades, providing the potential for an infectious disease to spread through the transportation network. by collecting information on the suspected place of infection, existing surveillance systems in industrialized countries may provide timely information for areas of the world without adequate surveillance currently in place. we present the results of a case study using reported cases of shigella dysenteriae serotyp ...200717239228
high genetic stability of integrons in clinical isolates of shigella spp. of worldwide origin.over a 12-year period, 68 shigella strains (31 s. sonnei, 30 s. flexneri, 4 s. dysenteriae, and 3 s. boydii strains) were collected in a french university hospital from the stools of patients who generally had a recent history of travel to various parts of the world (91%), particularly africa (67%). these strains were often resistant (streptomycin, spectinomycin, trimethoprim, tetracycline, and sulfonamides, 66 to 84%; ampicillin and chloramphenicol, 34 to 38%; nalidixic acid, 4%) and even multi ...200717242143
the catalase reaction of shigella species and its use in rapid screening for epidemic shigella dysenteriae type 1.as epidemic dysentery caused by shigella dysenteriae type 1 is associated with high mortality, early identification of outbreaks is important. since s. dysenteriae type 1 differs from most of the enterobacteriaceae in that it does not produce catalase, a test for catalase may provide a useful screening method. the ability of a catalase test to provide rapid identification of s. dysenteriae type 1 has now been assessed, using isolates of this pathogen from five continents, shigella of other speci ...200717244412
villin severing activity enhances actin-based motility in vivo.villin, an actin-binding protein associated with the actin bundles that support microvilli, bundles, caps, nucleates, and severs actin in a calcium-dependant manner in vitro. we hypothesized that the severing activity of villin is responsible for its reported role in enhancing cell plasticity and motility. to test this hypothesis, we chose a loss of function strategy and introduced mutations in villin based on sequence comparison with capg. by pyrene-actin assays, we demonstrate that this mutant ...200717182858
structural and genetic evidence that the escherichia coli o148 o antigen is the precursor of the shigella dysenteriae type 1 o antigen and identification of a glucosyltransferase gene.shigella dysenteriae type 1 is the most virulent serotype of shigella. enterotoxigenic escherichia coli o148 is pathogenic and can cause diarrhoea. the following structure was established for the tetrasaccharide repeating unit of the e. coli o148 o antigen: -->3)-alpha-l-rhap-(1-->3)-alpha-l-rhap-(1-->2)-alpha-d-glcp-(1-->3)-alpha-d-glcpnac-(1-->. this differs from the structure reported earlier for s. dysenteriae type 1 by having a glucose (glc) residue in place of a galactose (gal) residue. th ...200717185542
gene cluster analysis method identifies horizontally transferred genes with high reliability and indicates that they provide the main mechanism of operon gain in 8 species of gamma-proteobacteria.the formation mechanism of operons remains unresolved: operons may form by rearrangements within a genome or by acquisition of genes from other species, that is, horizontal gene transfer (hgt). one hindrance to its elucidation is the unavailability of a method to accurately identify hgt, although it is generally considered to occur. it is critically important first to select horizontally transferred (ht) genes reliably and then to determine the extent to which hgt is involved in operon formation ...200717185745
serological cross-reactivity of environmental isolates of enterobacter, escherichia, stenotrophomonas, and aerococcus with shigella spp.-specific antisera.using protocols designed for the isolation of shigella from environmental freshwater samples from different regions of bangladesh, 11 bacterial strains giving rise to shigella-like colonies on selective agar plates and showing serological cross-reaction with shigella-specific antisera were isolated. phylogenetic analyses revealed that three of the isolates were most closely related to escherichia coli, four to enterobacter sp., two to stenotrophomonas, and two isolates belonged to the gram-posit ...200717171463
shigella ipgb1 promotes bacterial entry through the elmo-dock180 machinery.shigella use a special mechanism to invade epithelial cells called 'the trigger mechanism of entry', which allows epithelial cells to trap several bacteria simultaneously. on contact, shigella deliver effectors into epithelial cells through the type iii secretion system. here, we show that one of the effectors, ipgb1, has a pivotal role in producing membrane ruffles by exploiting the rhog-elmo-dock180 pathway to stimulate rac1 activity. using pulldown assays, we identified engulfment and cell mo ...200717173036
vaccine potential for inactivated shigellae.we used human monocyte-derived dendritic cells (dc) and balb/c mice as models to establish the immunogenic and protective potential of formalin-inactivated shigella spp. incubation of dc with inactivated or live bacteria induced dc maturation and cytokine release. mice immunized orally or intranasally with killed s. flexneri, s. sonnei, or s. dysenteriae developed igg and fecal iga titers to the homologous lps. following respiratory challenge with the live homologous organisms, 80-100% survival ...200717178431
shigella rewrites host transcriptional responses. 200717179964
occurrence of campylobacter jejuni in shiraz, southwest iran.to investigate the occurrence of campylobacter jejuni among other bacterial agents of acute diarrhea.200717159366
an injected bacterial effector targets chromatin access for transcription factor nf-kappab to alter transcription of host genes involved in immune responses.phosphorylation of histone h3 at ser10 increases chromatin accessibility to transcription factor nf-kappab on a subset of genes involved in immune responses. here we report that a bacterial pathogen abrogated phosphorylation of histone h3 to 'shape' the transcriptional responses of infected host cells. we identify the shigella flexneri protein effector ospf as a dually specific phosphatase that dephosphorylated mitogen-activated protein kinases in the nucleus, thus preventing histone h3 phosphor ...200717159983
revisiting the molecular evolutionary history of shigella spp.the theory that shigella is derived from multiple independent origins of escherichia coli (pupo et al. 2000) has been challenged by recent findings that the virulence plasmids (vps) and the chromosomes share a similar evolutionary history (escobar-paramo et al. 2003), which suggests that an ancestral vp entered an e. coli strain only once, which gave rise to shigella spp. in an attempt to resolve these conflicting theories, we constructed three phylogenetic trees in this study: a robust chromoso ...200717160643
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