Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| chromosomal and plasmid-encoded enzymes are required for assembly of the r3-type core oligosaccharide in the lipopolysaccharide of escherichia coli o157:h7. | the type r3 core oligosaccharide predominates in the lipopolysaccharides from enterohemorrhagic escherichia coli isolates including o157:h7. the r3 core biosynthesis (waa) genetic locus contains two genes, waad and waaj, that are predicted to encode glycosyltransferases involved in completion of the outer core. through determination of the structures of the lipopolysaccharide core in precise mutants and biochemical analyses of enzyme activities, waaj was shown to be a udp-glucose:(galactosyl) li ... | 2004 | 15155763 |
| laboratory-confirmed shigellosis in the united states, 1989-2002: epidemiologic trends and patterns. | during 1989-2002, a total of 208,368 laboratory-confirmed shigella infections were reported to the centers for disease control and prevention. shigella sonnei accounted for 71.7%, shigella flexneri accounted for 18.4%, shigella boydii accounted for 1.6%, and shigella dysenteriae accounted for 0.7% of infections; for 7.6%, no serogroup was reported. national incidence rates ranged from 7.6 cases per 100,000 persons in 1993 to 3.7 cases per 100,000 persons in 1999. incidence rates for s. boydii, s ... | 2004 | 15156473 |
| actin-based bacterial motility: towards a definition of the minimal requirements. | at the border line between microbiology and cell biology, the spectacular capacity o f some intracellular bacterial pathogens, including listeria monocytogenes, shigella flexneri and several rickettsias, to use actin polymerization as a driving force for intracellular movement, cell-to-cell spreading and dissemination within the infected tissue is being increasingly studied. now that it is possible to manipulate the bacterial surface proteins involved in this process - acta o f l. monocytogenes ... | 1996 | 15157487 |
| regulated site-specific recombination of the she pathogenicity island of shigella flexneri. | the she pathogenicity island (pai) is a chromosomal, laterally acquired, integrative element of shigella flexneri that carries genes with established or putative roles in virulence. we demonstrate that spontaneous, precise excision of the element from its integration site in the 3' terminus of the phev trna gene is mediated by an integrase gene (int) and a gene designated rox (regulator of excision), both of which are carried on the she pai. integrase-mediated excision occurs via recombination b ... | 2004 | 15165236 |
| synthesis and immunochemical characterization of protein conjugates of carbohydrate and carbohydrate-mimetic peptides as experimental vaccines. | the peptides drpvpy and mdwnmhaa, which were identified as mimics of the cell-surface polysaccharides of streptococcus group a and shigella flexneri y, respectively, were used in this study to develop experimental vaccines directed against these two bacteria. both oligopeptides were synthesized employing the fmoc solid-phase strategy and linked via the amino end to a bifunctional linker, diethylsquarate. these adducts were then conjugated to the two carrier proteins, bovine serum albumin (bsa) a ... | 2004 | 15186860 |
| prevalence of the sat, set and sen genes among diverse serotypes of shigella flexneri strains isolated from patients with acute diarrhoea. | new virulence factors associated with the genus shigella have been described recently. these comprise enterotoxins shet-1 and shet-2, encoded by the set and sen genes, respectively, and the secreted autotransporter toxin sat, encoded by the sat gene. the present study aimed to determine the prevalence of genes encoding these toxins among a collection of shigella flexneri clinical isolates belonging to different serotypes. while the set gene was detected only in s. flexneri serotypes 2a and 2b, t ... | 2004 | 15191388 |
| [antibiotic resistance and molecular epidemiology of shigella spp. in northeastern argentina]. | to evaluate the antibiotic resistance of strains of shigella spp. isolated from feces samples from northeastern argentina and to characterize the strains in terms of their molecular epidemiology. | 2004 | 15193176 |
| a study on detecting and identifying enteric pathogens with pcr. | to develop a rapid and definite diagnostic test of bacterial enteritis caused by pathogenic enterobacteria, the most frequent etiologic agent of infectious enteritis in the world. | 2004 | 15202870 |
| regulation of the ysa type iii secretion system of yersinia enterocolitica by ysae/sycb and ysrs/ysrr. | yersinia enterocolitica biovar 1b contains two type iii secretion systems (ttsss), the plasmid-encoded ysc-yop system and the chromosomally encoded ysa-ysp system. proteins secreted from the ysa ttss (ysps) have only been detected in vitro when cells are cultured at 26 degrees c in a high-nacl medium. however, the exact role of the ysa ttss is unclear. thus, investigations into the regulation of this system may help elucidate the role of the ysps during the life cycle of y. enterocolitica. here ... | 2004 | 15205407 |
| short report: high incidence of shigellosis among peruvian soldiers deployed in the amazon river basin. | we investigated the etiology of acute diarrhea among peruvian military recruits undergoing three months of basic combat training near the amazonian city of iquitos. from january through september 2002, 307 of 967 recruits were seen at the health post for diarrhea (attack rate [ar] = 31.8%, incidence = 1.28 95% confidence interval [ci] = 1.14-1.43] episodes/person-year). shigella spp. were the most common bacterial pathogen recovered from recruits experiencing diarrhea episodes. these bacteria we ... | 2004 | 15211010 |
| [dysentery in poland in 2002]. | the notified number of dysentery cases was still very low, but a little higher than in 2001. only 220 cases were notified in the year 2002 (incidence 0.58/100,000 population) while 128 cases were notified in 2001 (incidence 0.33/100,000). no one death case was notified. four outbreaks of dysentery were observed: among them one foodborne infection due to s. sonnei involving 109 participants of a summer holiday camp for children from the poor families and one due to s. flexneri 2a involving 16 pat ... | 2004 | 15218646 |
| lactoferrin disruption of bacterial type iii secretion systems. | many gram-negative bacteria share a closely related mechanism for secretion of virulence proteins. this complex machine, the type iii secretion system, secretes virulence proteins in response to sensing the presence of target mammalian cells. we have found that recombinant human lactoferrin impairs the function of this system in two model organisms: shigella and enteropathogenic e. coli (epec). in the case of shigella, there is loss and degradation of two proteins secreted by the type iii mechan ... | 2004 | 15222474 |
| in vitro antimicrobial activity of essential oils from aromatic plants against selected foodborne pathogens. | the purpose of this study was to examine the effectiveness of selected essential oils for the control of growth and survival of pathogenic microorganisms of significant importance in food hygiene and to determine whether the antimicrobial effect was due to the major compounds of the oils. mic and mbc were determined by the tube dilution method. essential oils from thymus vulgaris from spain and france, salvia sclarea, salvia officinalis, salvia lavandulifolia, lavandula latifolia, lavandula angu ... | 2004 | 15222560 |
| mauve: multiple alignment of conserved genomic sequence with rearrangements. | as genomes evolve, they undergo large-scale evolutionary processes that present a challenge to sequence comparison not posed by short sequences. recombination causes frequent genome rearrangements, horizontal transfer introduces new sequences into bacterial chromosomes, and deletions remove segments of the genome. consequently, each genome is a mosaic of unique lineage-specific segments, regions shared with a subset of other genomes and segments conserved among all the genomes under consideratio ... | 2004 | 15231754 |
| mucosal immunization with attenuated shigella flexneri harboring an influenza hemagglutinin dna vaccine protects mice against a lethal influenza challenge. | mucosal surfaces are important for the induction of immunity against influenza virus. in a murine intranasal immunization model, we demonstrated that the attenuated shigella flexneri deltaasd strain 15d, carrying a dna construct encoding the influenza virus hemagglutinin (ha), induces protective immunity against a lethal respiratory challenge with influenza a/wsn/33. influenza virus-specific ifn-gamma t cells were detected among splenocytes, and anti-ha igg was detected in serum post-immunizatio ... | 2004 | 15246259 |
| identification of novel immunogenic proteins of shigella flexneri 2a by proteomic methodologies. | shigella spp. are one of the most important etiological factors for people who are living in developing countries and travelers to tropical countries. high priority has been given by the world health organization to the development of vaccines to control shigellosis caused by these bacteria. however, information regarding to profile of immunogenic proteins of shigella is not available now. in the present study, sub-immunoproteomics was applied to screen novel immunogenic proteins which could be ... | 2004 | 15246607 |
| improved methods for producing outer membrane vesicles in gram-negative bacteria. | outer membrane vesicle formation occurs during gram-negative bacterial growth. however, natural production of large amounts of outer membrane vesicles has only been described in a few bacterial genera. the purified vesicles of some bacterial pathogens have shown potential applications in vaccinology and in antibiotic therapy. this study focused on the development of a gene expression system able to induce production of large amounts of outer membrane vesicles. the tol-pal system of escherichia c ... | 2004 | 15249060 |
| detection of approximately 10(3) copies of dna by an electrochemical enzyme-amplified sandwich assay with ambient o(2) as the substrate. | the electrochemical sandwich-type, enzyme-amplified assay of zhang, kim, and heller (anal. chem. 2003, 75, 3267-3269) was simplified by replacing the amplifying horseradish peroxidase with bilirubin oxidase (bod). bod catalyzes the reduction of ambient o(2) to water and obviates the need for adding h(2)o(2). femtomolar (10(-)(15) m) concentrations of dna were detected at a 10-microm-diameter tip of a carbon fiber electrode. correspondingly, a few thousand copies of dna were detected in approxima ... | 2004 | 15253647 |
| a probabilistic measure for alignment-free sequence comparison. | alignment-free sequence comparison methods are still in the early stages of development compared to those of alignment-based sequence analysis. in this paper, we introduce a probabilistic measure of similarity between two biological sequences without alignment. the method is based on the concept of comparing the similarity/dissimilarity between two constructed markov models. | 2004 | 15271780 |
| excision of the shigella resistance locus pathogenicity island in shigella flexneri is stimulated by a member of a new subgroup of recombination directionality factors. | pathogenicity islands are capable of excision and insertion within bacterial chromosomes. we describe a protein, rox, that stimulates excision of the shigella resistance locus pathogenicity island in shigella flexneri. sequence analysis suggests that rox belongs to a new subfamily of recombination directionality factors, which includes proteins from p4, enterohemorrhagic escherichia coli, and yersinia pestis. | 2004 | 15292162 |
| the omptin family of enterobacterial surface proteases/adhesins: from housekeeping in escherichia coli to systemic spread of yersinia pestis. | the omptins are a family of enterobacterial surface proteases/adhesins that share high sequence identity and a conserved beta-barrel fold in the outer membrane. the omptins are multifunctional, and the individual omptins exhibit differing virulence-associated functions. the pla plasminogen activator of yersinia pestis contributes by several mechanisms to bacterial invasiveness and the systemic, uncontrolled proteolysis in plague. pla proteolytically activates the human proenzyme plasminogen and ... | 2004 | 15293449 |
| expression of his-tagged shigella ipac in arabidopsis. | although the expression of histidine (his)-tagged proteins in bacteria is routine, few his-tagged proteins have been expressed in plants, and no his-tagged proteins from bacterial pathogens have been expressed in plants, to our knowledge. here, we demonstrate expression of the shigella flexneri invasion plasmid antigen, ipac, in arabidopsis thaliana. s. flexneri is the causitive trigger for bacillary dysentery, and ipac is essential for bacterial entry into epithelial cells. ipac, attached to a ... | 2004 | 15313002 |
| validation of a pcr for diagnosis of typhoid fever and salmonellosis by amplification of the hila gene in clinical samples from colombian patients. | validation of a pcr test to detect hila gene sequences of salmonella spp. was performed in blood and faeces samples from typhoid fever and salmonellosis patients. sensitivity (s), specificity (sp), positive predictive value (ppv) and negative predictive value (npv) of the pcr in blood samples were performed by testing: 37 patients with clinical diagnosis of typhoid fever, 34 of them confirmed by isolation of s. typhi from blood cultures; 35 patients infected with other pathogens corroborated by ... | 2004 | 15314194 |
| growth inhibition of enteric pathogens by zinc sulfate: an in vitro study. | to determine the inhibition effect of zinc sulfate on isolates of enteric bacteria. | 2004 | 15316263 |
| the salmonella enterica serovar typhimurium divalent cation transport systems mnth and sitabcd are essential for virulence in an nramp1g169 murine typhoid model. | nramp1 is a transporter that pumps divalent cations from the vacuoles of phagocytic cells and is associated with the innate resistance of mice to diverse intracellular pathogens. we demonstrate that sita and mnth, genes encoding high-affinity metal ion uptake systems in salmonella enterica serovar typhimurium, are upregulated when salmonella is internalized by nramp1-expressing macrophages and play an essential role in systemic infection of congenic nramp1-expressing mice. | 2004 | 15322058 |
| il-8 is a key chemokine regulating neutrophil recruitment in a new mouse model of shigella-induced colitis. | the lack of a mouse model of acute rectocolitis mimicking human bacillary dysentery in the presence of invasive shigella is a major handicap to study the pathogenesis of the disease and to develop a shigella vaccine. the inability of the mouse intestinal mucosa to elicit an inflammatory infiltrate composed primarily of polymorphonuclear leukocytes (pmn) may be due to a defect in epithelial invasion, in the sensing of invading bacteria, or in the effector mechanisms that recruit the pmn infiltrat ... | 2004 | 15356171 |
| rafts can trigger contact-mediated secretion of bacterial effectors via a lipid-based mechanism. | infection by the gram-negative bacterial pathogen shigella flexneri depends on its ability to invade host cells. bacterial engulfment requires a functional type iii secretion system (ttss) allowing the translocation into host cells of bacterial effectors that activate cell-signaling cascades. we demonstrated previously that specialized lipid membrane domains enriched in cholesterol and sphingolipids (rafts) are involved during early steps of invasion, namely in binding and host cell entry. in th ... | 2004 | 15364928 |
| diarrhea in elderly patients due to clostridium difficile associated with salmonella and shigella infection. | clostridium difficile is the main cause of nosocomial diarrhea mainly in elderly hospitalized patients and in nursing homes, but less common in the community. we report three elderly patients living in the community, one frail and two in reasonable good health who recently developed diarrhea due to c. difficile associated with salmonella group c in two cases and shigella flexneri in the other. the association with shigella has not previously been reported and there have only been a few cases wit ... | 2004 | 15381346 |
| field trial of shigella flexneri iii vaccine; coproantibody studies. | 1950 | 15405854 | |
| on the nature of the toxic component of the somatic antigen of shigella paradysenteriae type z (flexner). | from the chemical evidence presented it appears that the toxicity associated with the somatic antigen of type z sh. paradysenteriae may be attributed to an entity distinct from the known components of the complex. that this substance is neither the protein, the lipid, nor the carbohydrate component of the antigen is evident. because of its lability to chemical manipulation, the nature of the toxic component, has not yet been ascertained. | 1950 | 15422094 |
| [intraspinal administration of chloromycetin in man; its use in a case of meningitis caused by shigella paradysenteriae]. | 1950 | 15424506 | |
| [a new shigella paradysenteriae serotype: the 112 type of cox and wallace]. | 1950 | 15433052 | |
| antibacterial and antifugal mono- and di-substituted symmetrical and unsymmetrical triazine-derived schiff-bases and their transition metal complexes. | a new series of antibacterial and antifungal triazine-derived mono- and di-substituted (symmetrical and unsymmetrical) schiff-bases and their cobalt(ii), copper(ii), nickel(ii) and zinc(ii) metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments and ir and electronic spectral measurements. ir spectra indicated the ligands to act as tridentate towards divalent metal ions via a trazine-n, the azomethine-n and, indole-nh and deproton ... | 2004 | 15449731 |
| invasive characteristics of apathogenic shigella flexneri 5a2c mutant obtained under the effect of furazolidone. | apathogenic shigella flexneri 5a2c mutant treated with furazolidone can infect eucaryotic cells. these bacteria contain no virulence genes responsible for sh. flexneri invasion, which seems to be the cause of their apathogenicity. the capacity of bacteria to penetrate into eucaryotic cells correlates with the appearance of ecp 32 protease specifically cleaving actin. | 2004 | 15455123 |
| psi-phi: exploring the outer limits of bacterial pseudogenes. | because bacterial chromosomes are tightly packed with genes and were traditionally viewed as being optimized for size and replication speed, it was not surprising that the early annotations of sequenced bacterial genomes reported few, if any, pseudogenes. but because pseudogenes are generally recognized by comparisons with their functional counterparts, as more genome sequences accumulated, many bacterial pathogens were found to harbor large numbers of truncated, inactivated, and degraded genes. ... | 2004 | 15479949 |
| mutants of agrobacterium tumefaciens virg gene that activate transcription of vir promoter in escherichia coli. | the vira and virg two-component regulatory system is essential for transcriptional activation of virulence (vir) genes in agrobacterium tumefaciens in the presence of inducer molecules. the vira/virg mediated vir gene transcription depends on a specific interaction between the c-terminal domain of the alpha subunit (rpoa) of a. tumefaciens rna polymerase (rnap) and n-terminal domain of the virg. however, such interaction does not occur between rnap of e. coli and the virg, thus vir gene activati ... | 2004 | 15486707 |
| [identification of a protein interacting with shigella flexneri ipac invasin by yeast two-hybrid system]. | two-hybrid system was applied to screen proteins interacting with ipac in the host cell. by using two-hybrid system, the bait plasmid containing ipac gene was constructed and designated pgbkt-ipac. a human hela cdna library was screened to isolate protein factors that might interact with ipac. among the 2 x 10(6) clones screened, 22 positive clones were picked out. sequence analysis revealed that two of them contained cdna fragments from collagenase. subsequently the domain of ipac interacting w ... | 2004 | 15487505 |
| osa protein constitutes a strong oncogenic suppression system that can block vir-dependent transfer of incq plasmids between agrobacterium cells and the establishment of incq plasmids in plant cells. | the osa (oncogenic suppressive activity) gene of the incw group plasmid psa is sufficient to suppress tumorigenesis by agrobacterium tumefaciens. osa confers oncogenic suppression by inhibiting vire2 protein export. this result is similar, but not identical, to that of oncogenic suppression by the incq plasmid rsf1010. we conducted a series of experiments to compare oncogenic suppression by these two systems. agrobacterium strains harboring plasmids containing osa are more able to effect oncogen ... | 2004 | 15489437 |
| shiga toxin-encoding bacteriophages--genomes in motion. | shiga toxins (stx) represent a group of bacterial toxins that are involved in human and animal disease. stx are mainly produced by escherichia coli isolated from human and non-human sources, shigella dysenteriae type 1, and sporadically, by citrobacter freundii, enterobacter cloacae and shigella flexneri. the genes encoding stx are encoded in the genome of heterogeneous lambdoid prophages (stx-converting bacteriophages; stx-phages). they are located in a similar position in the late region of th ... | 2004 | 15493821 |
| deletion in the shigella enterotoxin genes further attenuates shigella flexneri 2a bearing guanine auxotrophy in a phase 1 trial of cvd 1204 and cvd 1208. | we created a live, attenuated, oral shigella vaccine by constructing a lineage of guanine auxotrophs and conducted a double-blind, placebo-controlled trial to ascertain (1) the attenuation profile of delta guaba shigella flexneri 2a, which harbors deletions in the guanine nucleotide synthesis pathway (cvd 1204); (2) additional attenuation conferred by deletions in set and sen genes encoding shigella enterotoxins (shets) 1 and 2, respectively (cvd 1208); and (3) the relative immunogenicity of the ... | 2004 | 15499528 |
| complex multiple antibiotic and mercury resistance region derived from the r-det of nr1 (r100). | the sequence of the 45.2-kb multidrug and mercury resistance region of prmh760, a large plasmid from a clinical isolate of klebsiella pneumoniae collected in 1997 in australia, was completed. most of the modules found in the resistance determinant (r-det), or tn2670, region of nr1 (also known as r100), isolated from a shigella flexneri strain in japan in the late 1950s, were present in prmh760 but in a different configuration. the location was also different, with the tn2670-derived region flank ... | 2004 | 15504849 |
| traditional medicine in sakarya province (turkey) and antimicrobial activities of selected species. | traditional medicine in north-west of turkey (sakarya province) were studied during a 2 months field study by interviewing local informants from several villages. plant species used to treat infections were tested for antimicrobial activity. information was collected for 46 plant species from 30 families and for 5 animal species. twenty four of the plant species were cultivated. most used families were asteraceae, cucurbitaceae, lamiaceae and rosaceae and the most used plants were artemisia absi ... | 2004 | 15507351 |
| single-molecule approach to bacterial genomic comparisons via optical mapping. | modern comparative genomics has been established, in part, by the sequencing and annotation of a broad range of microbial species. to gain further insights, new sequencing efforts are now dealing with the variety of strains or isolates that gives a species definition and range; however, this number vastly outstrips our ability to sequence them. given the availability of a large number of microbial species, new whole genome approaches must be developed to fully leverage this information at the le ... | 2004 | 15516592 |
| direct and indirect transcriptional activation of virulence genes by an arac-like protein, pera from enteropathogenic escherichia coli. | the plasmid-encoded per regulatory locus of enteropathogenic escherichia coli (epec) is generally considered to consist of three genes, pera, perb and perc. pera, a member of the arac-like family of transcriptional regulators, is known to be an activator of its own promoter (autoactivation) as well as of the plasmid-located bfp operon encoding bundle-forming pili, but its role in activation of the chromosomal locus of enterocyte effacement (lee) pathogenicity island, which confers the property o ... | 2004 | 15522091 |
| viability of escherichia coli topa mutants lacking dna topoisomerase i. | the viability of the topa mutants lacking dna topoisomerase i was thought to depend on the presence of compensatory mutations in escherichia coli but not salmonella typhimurium or shigella flexneri. this apparent discrepancy in topa requirements in different bacteria prompted us to reexamine the topa requirements in e. coli. we find that e. coli strains bearing topa mutations, introduced into the strains by dna-mediated gene replacement, are viable at 37 or 42 degrees c without any compensatory ... | 2005 | 15522872 |
| multiple roles of clan (caspase-associated recruitment domain, leucine-rich repeat, and naip ciia het-e, and tp1-containing protein) in the mammalian innate immune response. | naip ciia het-e and tp1 (nacht) family proteins are involved in sensing intracellular pathogens or pathogen-derived molecules, triggering host defense responses resulting in caspase-mediated processing of proinflammatory cytokines and nf-kappab activation. caspase-associated recruitment domain, leucine-rich repeat, and nacht-containing protein (clan), also known as ice protease-activating factor, belongs to a branch of the nacht family that contains proteins carrying caspase-associated recruitme ... | 2004 | 15528373 |
| identification of escherichia coli o157 : h7 genes influencing colonization of the bovine gastrointestinal tract using signature-tagged mutagenesis. | enterohaemorrhagic escherichia coli (ehec) cause acute gastroenteritis in humans that may be complicated by life-threatening systemic sequelae. the predominant ehec serotype affecting humans in the uk and north america is o157 : h7 and infections are frequently associated with contact with ruminant faeces. strategies to reduce the carriage of ehec in ruminants are expected to lower the incidence of human ehec infections; however, the molecular mechanisms underlying persistence of ehec in ruminan ... | 2004 | 15528651 |
| bacteria as dna vaccine carriers for genetic immunization. | genetic immunization with plasmid dna vaccines has proven to be a promising tool in conferring protective immunity in various experimental animal models of infectious diseases or tumors. recent research focuses on the use of bacteria, in particular enteroinvasive species, as effective carriers for dna vaccines. attenuated strains of shigella flexneri, salmonella spp., yersinia enterocolitica or listeria monocytogenes have shown to be attractive candidates to target dna vaccines to immunological ... | 2004 | 15532991 |
| cloning, sequencing and partial characterisation of sorbitol transporter (srlt) gene encoding phosphotransferase system, glucitol/sorbitol-specific iibc components of erwinia herbicola atcc 21998. | a dna fragment of approximately 1500 bp, harbouring the sorbitol transport gene (srlt), was amplified from the chromosomal dna of erwinia herbicola atcc 21998 by pcr and cloned in escherichia coli jm109. degenerate oligonucleotide primers used were designed based on the conserved regions in the gene sequences within the gut operon of e. coli (gene bank accession no. j02708) and the srl operon of erwinia amylovora (gene bank accession no. y14603). the cloned dna fragment was sequenced and found t ... | 2004 | 15560368 |
| escape of intracellular shigella from autophagy. | the degradation of undesirable cellular components or organelles, including invading microbes, by autophagy is crucial for cell survival. here, shigella, an invasive bacteria, was found to be able to escape autophagy by secreting icsb by means of the type iii secretion system. mutant bacteria lacking icsb were trapped by autophagy during multiplication within the host cells. icsb did not directly inhibit autophagy. rather, shigella virg, a protein required for intracellular actin-based motility, ... | 2004 | 15576571 |
| experimental study on the antibacterial effect of origanum volatile oil on dysentery bacilli in vivo and in vitro. | to observe the germistatic and germicidal effects of origanum volatile oil (ovi) on the dysentery bacteria, the abdominal cavity of mice was infected with shigella sonne (sh. sonnei) and shigella flexneri (sh. flexneri) f2a. after ovi was given to the mice via gastric lavage, the effects of ovi on the infected mice were observed. the minimal inhibitory concentration (mic) and minimal bactericidal concentration (mbc) for dysentery bacteria were determined in vitro. the results showed that origanu ... | 2004 | 15587409 |
| transcriptional adaptation of shigella flexneri during infection of macrophages and epithelial cells: insights into the strategies of a cytosolic bacterial pathogen. | shigella flexneri, the etiologic agent of bacillary dysentery, invades epithelial cells as well as macrophages and dendritic cells and escapes into the cytosol soon after invasion. dissection of the global gene expression profile of the bacterium in its intracellular niche is essential to fully understand the biology of shigella infection. we have determined the complete gene expression profiles for s. flexneri infecting human epithelial hela cells and human macrophage-like u937 cells. approxima ... | 2005 | 15618144 |
| construction and characterization of bivalent shigella flexneri 2a vaccine strains sc608(pcfai) and sc608(pcfai/ltb) that express antigens from enterotoxigenic escherichia coli. | an invasive strain of shigella flexneri 2a (sc608) has been developed as a vector for the expression and delivery of heterologous antigens. sc608 is an aspartate semialdehyde dehydrogenase (asd) derivative of sc602 (icsa iuc), a well-characterized live attenuated vaccine strain which has undergone several clinical trials in human volunteers. when administered orally at a single 10(4) (cfu) dose, sc602 is both immunogenic and efficacious against shigellosis. using asd-based plasmid vectors, we de ... | 2005 | 15618162 |
| virulent shigella flexneri causes damage to mitochondria and triggers necrosis in infected human monocyte-derived macrophages. | shigella flexneri is a gram-negative bacterium that causes bacillary dysentery in humans that is characterized by an acute inflammatory response of the colon. the fate of phagocytes that are infected in vitro with virulent shigella has been the subject of some investigation and debate. in this study we found that virulent shigella caused a rapid increase in the cell membrane permeability of infected human monocyte-derived macrophages (hmdm) but not in the cell membrane permeability of monocytes, ... | 2005 | 15618190 |
| screening and identification of shigella flexneri 2a virulence-related genes induced after invasion of epithelial cells. | an in vivo expression technology (ivet) was applied to screen s. flexneri 2a genes induced after invasion of epithelial cells, and virulence-related genes were further identified by mutational analysis. thirteen intracellular induced genes were identified with a hela cell infection model. of these, two were identified as alkylation-related genes; one was related to metabolism; one encoded a transcriptional regulator; three were identified as insertion elements; three appeared to be antisense to ... | 2004 | 15620105 |
| crystal structure of the copper homeostasis protein (cutcm) from shigella flexneri at 1.7 a resolution: the first structure of a new sequence family of tim barrels. | 2005 | 15624211 | |
| bacteria spurned by self-absorbed cells. | 2005 | 15635436 | |
| antimicrobial resistance of shigella flexneri serotypes in israel during a period of three years: 2000-2002. | this is a surveillance study of the antimicrobial resistance of the s. flexneri group in the context of its serotype diversity. it includes 1422 isolates, which were sent to the national shigella reference centre (nsrc) by hospitals and outpatient clinics in israel during a 3-year period (2000-2002). the strains were identified and classified according to the prevalence and antigenic structure of their serotypes. all samples were checked for resistance to ampicillin (amp), trimethoprim-sulphamet ... | 2004 | 15635961 |
| [choice of informative characteristics for the characterization of the adaptive process in the population of rod-shaped bacteria]. | different data characterizing the growth and development of rod-shaped bacterial cells (shigella flexneri strains s and rd) at the initial stage of the formation of their populations on a solid culture medium were analyzed with a view to the evaluation of the adaptive process. the study revealed that lo and lk (initial and end of bacterial lenght) and tau (generation time) of cells were the optimal informative characteristics. the determination of these characteristics on the cell population lev ... | 2004 | 15636132 |
| [construction of sw480 cell model identifying shigella virulent genes]. | signature-tagged mutagenesis (stm) is a novel technology with high throughput screening ability to identify virulent genes of pathogen in vivo. an appropriate animal or cell line model is one of prerequisites by exploiting this technique. in order to apply stm to shigella flexneri, rc426 was constructed as an attenuated mutant with chloramphenicol resistance and aroa and virg genes inactivated by homologous recombination; another attenuated strain t32 was used as an oral s. flexneri 2a vaccine d ... | 2004 | 15640048 |
| inactivation of escherichia coli o157:h7 in simulated human gastric fluid. | human disease caused by escherichia coli o157:h7 is a function of the number of cells that are present at potential sites of infection and host susceptibility. such infectious doses are a result, in part, of the quantity of cells that are ingested and that survive human host defenses, such as the low-ph environment of the stomach. to more fully understand the kinetics of e. coli o157:h7 survival in gastric fluid, individual e. coli o157:h7 strains were suspended in various media (i.e., saline, c ... | 2005 | 15640204 |
| isatin-derived antibacterial and antifungal compounds and their transition metal complexes. | a series of isatins incorporating thiazole, thiadiazole, benzothiazole and p-toluene sulfonyl hydrazide moieties, along with their cobalt(ii), copper(ii), nickel(ii) and zinc(ii) metal complexes have been synthesized and characterized by elemental analyses, molar conductances, magnetic moments, ir, nmr and electronic spectral data. these compounds have been screened for antibacterial activity against escherichia coli, bacillus subtillis, shigella flexneri, staphylococcus aureus, pseudomonas aeru ... | 2004 | 15648656 |
| the generalized transducing salmonella bacteriophage es18: complete genome sequence and dna packaging strategy. | the generalized transducing double-stranded dna bacteriophage es18 has an icosahedral head and a long noncontractile tail, and it infects both rough and smooth salmonella enterica strains. we report here the complete 46,900-bp genome nucleotide sequence and provide an analysis of the sequence. its 79 genes and their organization clearly show that es18 is a member of the lambda-like (lambdoid) phage group; however, it contains a novel set of genes that program assembly of the virion head. most of ... | 2005 | 15659686 |
| a novel intranasal protollin-based measles vaccine induces mucosal and systemic neutralizing antibody responses and cell-mediated immunity in mice. | protollin-mv is a vaccine produced by mixing split measles virus (mv) antigen with the novel adjuvant protollin (neisseria meningitidis outer membrane proteins non-covalently complexed with shigella flexneri 2a lipopolysaccharide). intranasal immunization of mice with two or three doses of protollin-mv induces both serum igg and mucosal iga with strong neutralizing activity. there is a dose-dependent shift towards lower igg1:igg2a ratios and mv-specific ifngamma production in splenocytes. intran ... | 2005 | 15661386 |
| modulation of an outer membrane protease contributes to the virulence defect of shigella flexneri strains carrying a mutation in the virk locus. | the shigella actin assembly protein icsa is removed from the bacterial surface by the protease icsp. we show that decreased intracellular spreading of virk::tn10 mutants is due in part to significant increases in icsp and icsp-mediated cleavage of icsa and that icsp expression is a critical determinant of shigella virulence. | 2005 | 15664968 |
| sensitive and rapid detection of shigella and enteroinvasive escherichia coli by a loop-mediated isothermal amplification method. | here we report a loop-mediated isothermal amplification (lamp) method for detecting shigella and enteroinvasive escherichia coli. the target for this lamp method is the ipah gene which is carried by both of the pathogens. the lamp method efficiently detected the gene within 2 h at a minimal amount of bacteria (8 cfu) per reaction. | 2005 | 15668027 |
| synthesis of two linear padre conjugates bearing a deca- or pentadecasaccharide b epitope as potential synthetic vaccines against shigella flexneri serotype 2a infection. | the blockwise synthesis of the 2-aminoethyl glycosides of a deca- and a pentadecasaccharide made of two and three repeating units, respectively, of the shigella flexneri serotype 2a specific polysaccharide is reported. the strategy relies on trifluoromethanesulfonic acid mediated glycosylation of a pentasaccharide building block acting as a glycosyl donor and a potential glycoside acceptor. both targets were made available in amounts large enough for their subsequent conversion into glycoconjuga ... | 2005 | 15669066 |
| physiological stress of intracellular shigella flexneri visualized with a metabolic sensor fused to a surface-reporter system. | when deleted of its n-terminal signal-reception domain, the broad host range sigma54-dependent transcriptional regulator xylr, along with its cognate promoter pu, becomes a sensor of the metabolic stress of the carrier bacteria. we have employed a surface reporter system to visualize the physiological status of intracellular shigella flexneri during infection of henle 407 cells in culture. to this end, the xylrdeltaa gene has been engineered adjacent to a bicistronic transcriptional fusion of pu ... | 2005 | 15670852 |
| cloning of a novel gene for quinolone resistance from a transferable plasmid in shigella flexneri 2b. | a novel gene for quinolone resistance was cloned from a transferable plasmid carried by a clinical isolate of shigella flexneri 2b that was resistant to fluoroquinolones. the plasmid conferred low-level resistance to quinolones on escherichia coli hb101. the protein encoded by the gene showed 59% amino acid identity with qnr. | 2005 | 15673773 |
| occurrence of integrons and resistance genes among sulphonamide-resistant shigella spp. from brazil. | to determine the occurrence of class 1 and 2 integrons and antimicrobial resistance genes among sulphonamide-resistant shigella strains isolated in brazil during 1999-2003. | 2005 | 15681578 |
| a novel caspase-1/toll-like receptor 4-independent pathway of cell death induced by cytosolic shigella in infected macrophages. | shigella-induced macrophage cell death is an important step in the induction of acute inflammatory responses that ultimately lead to bacillary dysentery. cell death was previously reported to be dependent upon the activation of caspase-1 via interaction with ipab secreted by intracellular shigella, but in this study, we show that shigella infection of macrophages can also induce cell death independent of caspase-1 or ipab activity. time-lapse imaging and electron microscopic analyses indicated t ... | 2005 | 15695506 |
| a novel shigella dysenteriae serovar isolated in canada. | the etiological agent most commonly associated with bacillary dysentery is shigella. as part of its mandate, the bacteriology and enteric disease program of health canada identifies and serotypes unusual isolates of shigella received from provincial laboratories of public health. in this report, six unusual isolates from three provinces were analyzed biochemically and serologically using slide and tube agglutinations and molecularly using standard pulsed-filed gel electrophoresis (pfge), pcr, an ... | 2005 | 15695673 |
| effects of zinc supplementation as adjunct therapy on the systemic immune responses in shigellosis. | zinc is lost during diarrheal diseases, and zinc deficiency induces intestinal morphology-altering inflammatory responses that zinc supplementation can correct. | 2005 | 15699240 |
| etiology of diarrhea in pediatric outpatient settings. | the frequency with which bacteria cause diarrhea evaluated in ambulatory settings is often unknown. we attempted to determine the microbiologic etiology of diarrhea in a private pediatric practice (site a) and a clinic serving largely immigrant children (site b) and to establish guidelines for bacterial culture. | 2005 | 15702043 |
| serum amyloid a protein binds to outer membrane protein a of gram-negative bacteria. | serum amyloid a (saa) is the major acute phase protein in man and most mammals. we observed saa binding to a surprisingly large number of gram-negative bacteria, including escherichia coli, salmonella typhimurium, shigella flexneri, klebsiella pneumoniae, vibrio cholerae, and pseudomonas aeruginosa. the binding was found to be high affinity and rapid. importantly, this binding was not inhibited by high density lipoprotein with which saa is normally complexed in serum. binding was also observed w ... | 2005 | 15705572 |
| detection of virulence genes in malaysian shigella species by multiplex pcr assay. | in malaysia, shigella spp. was reported to be the third commonest bacterial agent responsible for childhood diarrhoea. currently, isolation of the bacterium and confirmation of the disease by microbiological and biochemical methods remain as the "gold standard". this study aimed to detect the prevalence of four shigella virulence genes present concurrently, in randomly selected malaysian strains via a rapid multiplex pcr (mpcr) assay. | 2005 | 15707504 |
| topological analysis of gtra and gtrb proteins encoded by the serotype-converting cassette of shigella flexneri. | serotype conversion (o-antigen glucosylation) in shigella flexneri is mediated by temperate bacteriophages, which encode a three-gene cluster that contains gtra, gtrb, and gtr([type]). sequence analysis has revealed that gtra and gtrb are conserved and readily interchangeable between serotypes. the gtr([type]) is unique in each serotype and responsible for specifically mediating conversion by the addition of a glucosyl group to the o-antigen units. analysis of the gtra and gtrb amino acid sequen ... | 2005 | 15708010 |
| gastroenteritis in us marines during operation iraqi freedom. | approximately 83,000 us marines participated in the opening phase of operation iraqi freedom in spring 2003. a navy preventive medicine laboratory was set up in ad diwaniyah, iraq, to provide clinical diagnostic support for marine medical units during a period of repositioning in south-central iraq. | 2005 | 15712073 |
| clustering of database sequences for fast homology search using upper bounds on alignment score. | homology data are among the most important information used to predict the functions of unknown proteins and thus fast and accurate methods are needed. in this paper, we propose a new approach for fast and accurate homology search using pre-computed all-against-all similarity scores in a target database. we previously developed a method for derivation of an upper bound of the smith-waterman score (sw-score) between a query and a homolog candidate sequence using the sw-score between the candidate ... | 2004 | 15712113 |
| genetic analysis of antibiotic-resistance determinants in multidrug-resistant shigella strains isolated from chilean children. | a total of 162 clinical isolates of shigella collected from children in a semi-rural community of chile were examined for the presence of genetic determinants of resistance to ampicillin, chloramphenicol, tetracycline, and trimethoprim. ampicillin resistance was most frequently associated with the presence of bla(oxa) in s. flexneri and with bla(tem) in s. sonnei. the bla(oxa) gene but not bla(tem) was located in class 1 integrons. the dhfria gene encoding for resistance to trimethoprim was asso ... | 2005 | 15724714 |
| role of the pst system in plaque formation by the intracellular pathogen shigella flexneri. | in response to the host cell environment, the intracellular pathogen shigella flexneri induces the expression of numerous genes, including those in the pst operon which is predicted to encode a high-affinity phosphate acquisition system that is expressed under reduced phosphate conditions. an s. flexneri pst mutant forms smaller plaques in henle cell monolayers than does the parental strain. this mutant exhibited normal production and localization of the s. flexneri icsa protein. the pst mutant ... | 2005 | 15731038 |
| ipad of shigella flexneri is independently required for regulation of ipa protein secretion and efficient insertion of ipab and ipac into host membranes. | shigella flexneri causes human dysentery after invading the cells of the colonic epithelium. the best-studied effectors of shigella entry into colonocytes are the invasion plasmid antigens ipac and ipab. these proteins are exported via a type iii secretion system (ttss) to form a pore in the host membrane that may allow the translocation of other effectors into the host cytoplasm. ttss-mediated secretion of ipad is also required for translocation pore formation, bacterial invasion, and virulence ... | 2005 | 15731041 |
| microbiology. a pathogen attacks while keeping up defense. | 2005 | 15731433 | |
| optimization of virulence functions through glucosylation of shigella lps. | shigella, the leading cause of bacillary dysentery, uses a type iii secretion system (ttss) to inject proteins into human cells, leading to bacterial invasion and a vigorous inflammatory response. the bacterium is protected against the response by the o antigen of lipopolysaccharide (lps) on its surface. we show that bacteriophage-encoded glucosylation of shigella o antigen, the basis of different serotypes, shortens the lps molecule by around half. this enhances ttss function without compromisi ... | 2005 | 15731456 |
| shigella antibiotic resistance in central turkey: comparison of the years 1987-1994 and 1995-2002. | the epidemiology and antibiotic susceptibility of shigella species changes over time. updated susceptibility knowledge is necessary for appropriate empirical antibiotic treatment. | 2005 | 15735493 |
| environmental ph sensing: resolving the vira/virg two-component system inputs for agrobacterium pathogenesis. | agrobacterium tumefaciens stands as one of biotechnology's greatest successes, with all plant genetic engineering building on the strategies of this pathogen. by integrating responses to external phs, phenols, and monosaccharides, this organism mobilizes oncogenic elements to efficiently transform most dicotyledonous plants. we now show that the complex signaling network used to regulate lateral gene transfer can be resolved as individual signaling modules. while ph and sugar perception are coup ... | 2005 | 15743967 |
| molecular epidemiology of shigella flexneri in a long-stay psychiatric nursing center during 2001 to 2003. | with six separate wards accommodating more than 1,600 patients, v nursing center (vnc) is a long-stay psychiatric nursing center in eastern taiwan. during 2001 to 2003, 39 shigellosis cases occurred in vnc. different from the notion that most cases of shigellosis are caused by shigella sonnei, all except one of these cases were caused by s. flexneri, with the remaining one caused by an s. sonnei isolate. o-antigen serotyping showed that the 38 s. flexneri strains were of either type 1a (n = 20) ... | 2005 | 15750107 |
| analysis of virulence plasmid gene expression defines three classes of effectors in the type iii secretion system of shigella flexneri. | proteins directly involved in entry and dissemination of shigella flexneri into epithelial cells are encoded by a virulence plasmid of 200 kb. a 30-kb region (designated the entry region) of this plasmid encodes components of a type iii secretion (tts) apparatus, substrates of this apparatus and their dedicated chaperones. during growth of bacteria in broth, expression of these genes is induced at 37 degrees c and the tts apparatus is assembled in the bacterial envelope but is not active. secret ... | 2005 | 15758240 |
| [change of serological properties of museum strains of shigella flexneri in different terms of storage]. | the viability, purity, biological and serological properties of museum strains of shigella flexneri which were kept in lyophilized state during above 30 years were studied. primary serological characteristics were specified, it was established that type 2a is the predominant serotype independent of the years and regions of isolation. some strains lost antigens as a result of the long-term preservation or reinoculation on agar media. | 2005 | 15765879 |
| bacteriophage-encoded glucosyltransferase gtrii of shigella flexneri: membrane topology and identification of critical residues. | the shigella flexneri serotypes differ in the nature of their o-antigens. the addition of glucosyl or o-acetyl groups to the common backbone repeat units gives rise to the different serotypes. gtrii glucosylates rhamnose iii of the o-antigen repeat unit, thus converting serotype y (which has no modifications to the basic o-antigen repeat unit) into serotype 2a, the most prevalent serotype. in the present study, the topology of gtrii has been determined. gtrii has nine transmembrane helices, a re ... | 2005 | 15766330 |
| frameshifting by transcriptional slippage is involved in production of mxie, the transcription activator regulated by the activity of the type iii secretion apparatus in shigella flexneri. | bacteria of shigella spp. are responsible for shigellosis in humans. they use a type iii secretion (tts) system encoded by a 200 kb virulence plasmid to enter epithelial cells and trigger apoptosis in macrophages. this tts system comprises a secretion apparatus, translocators and effectors that transit through this apparatus, cytoplasmic chaperones and specific transcription regulators. the tts apparatus assembled during growth of shigella flexneri in broth is activated upon contact with epithel ... | 2005 | 15773990 |
| structure and biochemical analysis of a secretin pilot protein. | the ability to translocate virulence proteins into host cells through a type iii secretion apparatus (ttss) is a hallmark of several gram-negative pathogens including shigella, salmonella, yersinia, pseudomonas, and enteropathogenic escherichia coli. in common with other types of bacterial secretion apparatus, the assembly of the ttss complex requires the preceding formation of its integral outer membrane secretin ring component. we have determined at 1.5 a the structure of mxim28-142, the shige ... | 2005 | 15775974 |
| surprising dependence on postsegregational killing of host cells for maintenance of the large virulence plasmid of shigella flexneri. | low-copy-number plasmids all encode multiple systems to ensure their propagation, including replication, partition (active segregation), and postsegregational killing (psk) systems. psk systems kill those rare cells that lose the plasmid due to replication or segregation errors. psk systems should not be used as the principle means of maintaining the plasmid. the metabolic cost of killing the many cured cells that would arise from random plasmid segregation is far too high. here we describe an i ... | 2005 | 15805523 |
| [small treatise on art of warfare... from shigella]. | 2005 | 15811311 | |
| comparative imaging of a bacterial surface-located gfp fusion protein by epifluorescence and scanning near-field optical microscopy. | icsa is an autotransporter protein that plays a role in the virulence of shigella bacteria. we have examined the cellular localization of a fusion of an icsa fragment to the green fluorescent protein (gfp) expressed in escherichia coli using a dual epifluorescence and scanning near-field optical microscope. by combining the data obtained from far-field with near-field microscopy of the same sample, discrimination between surface-bound fusion proteins and fusion proteins located in the cellular c ... | 2005 | 15817062 |
| cholesterol binding by the bacterial type iii translocon is essential for virulence effector delivery into mammalian cells. | a ubiquitous early step in infection of man and animals by enteric bacterial pathogens like salmonella, shigella and enteropathogenic escherichia coli (epec) is the translocation of virulence effector proteins into mammalian cells via specialized type iii secretion systems (ttsss). translocated effectors subvert the host cytoskeleton and stimulate signalling to promote bacterial internalization or survival. target cell plasma membrane cholesterol is central to pathogen-host cross-talk, but the p ... | 2005 | 15819617 |
| new antimicrobial nitrofuran, trans-5-amino-3-[2-(5-nitro-2-furyl)vinyl]-delta2-1,2,4-oxadiazole: antimicrobial efficacy in mice, rats, and guinea pigs. | a new antimicrobial nitrofuran designated sq 18,506 showed some therapeutic activity when administered orally to mice infected with escherichia coli, salmonella schottmuelleri, shigella flexneri, or klebsiella pneumoniae. animals infected parenterally with streptococcus pyogenes, proteus mirabilis, mycobacterium tuberculosis, and candida albicans, or topically with trichophyton mentagrophytes, did not respond to therapy with the drug at the dosage levels used. the compound was as effective as me ... | 1974 | 15830472 |
| modulation of host cytoskeleton function by the enteropathogenic escherichia coli and citrobacter rodentium effector protein espg. | espg is a conserved protein encoded by the locus of enterocyte effacement (lee) of attaching and effacing (a/e) pathogens, including enteropathogenic and enterohemorrhagic escherichia coli and citrobacter rodentium. espg is delivered into infected host cells by a type iii secretion system. the role of espg in virulence has not yet been defined. here we describe experiments that probe the virulence characteristics and biological activities of espg in vitro and in vivo. a c. rodentium espg mutant ... | 2005 | 15845460 |
| model for the combined effects of temperature, ph and sodium chloride concentration on survival of shigella flexneri strain 5348 under aerobic conditions. | shigella is recognized as a major foodborne pathogen; however, relatively few studies have been reported on its growth and survival characteristics, particularly under conditions relevant to food. a fractional factorial design was used to measure the effects and interactions of temperature (4-37 degrees c), ph (2-6) and nacl (0.5-9%) on survival kinetics of shigella flexneri strain 5348 in bhi broth. stationary-phase cells were inoculated into sterile media to give initial populations of 6-7 log ... | 2005 | 15862880 |
| plasmid partition system of the p1par family from the pwr100 virulence plasmid of shigella flexneri. | p1par family members promote the active segregation of a variety of plasmids and plasmid prophages in gram-negative bacteria. each has genes for para and parb proteins, followed by a pars partition site. the large virulence plasmid pwr100 of shigella flexneri contains a new p1par family member: pwr100par. although typical para and parb genes are present, the putative pwr100pars site is atypical in sequence and organization. however, pwr100pars promoted accurate plasmid partition in escherichia c ... | 2005 | 15866921 |