Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| involvement of fis in the h-ns-mediated regulation of virf gene of shigella and enteroinvasive escherichia coli. | the mechanism of pathogenicity in shigella and enteroinvasive escherichia coli (eiec) requires the co-ordinated expression of several genes located on both the virulence plasmid and the chromosome. we found that cells lacking a functional fis protein (factor for inversion stimulation) are partially impaired in expressing the virulence genes and that full expression is totally restored when shigella wild-type fis gene is offered in trans. we also identified virf, among the virulence genes, as a t ... | 2001 | 11703666 |
| ipac from shigella and sipc from salmonella possess similar biochemical properties but are functionally distinct. | invasion plasmid antigen c (ipac) is secreted via the type iii secretion system (ttss) of shigella flexneri and serves as an essential effector molecule for epithelial cell invasion. the only homologue of ipac identified thus far is salmonella invasion protein c (sipc/sspc), which is essential for enterocyte invasion by salmonella typhimurium. to explore the biochemical and functional relatedness of ipac and sipc, recombinant derivatives of both proteins were purified so that their in vitro bioc ... | 2001 | 11703668 |
| pathoadaptive mutations that enhance virulence: genetic organization of the cada regions of shigella spp. | pathoadaptive mutations improve the fitness of pathogenic species by modification of traits that interfere with factors (virulence and ancestral) required for survival in host tissues. a demonstrated pathoadaptive mutation is the loss of lysine decarboxylase (ldc) expression in shigella species that have evolved from ldc-expressing escherichia coli. previous studies demonstrated that the product of ldc activity, cadaverine, blocks the action of shigella enterotoxins and that the gene encoding ld ... | 2001 | 11705922 |
| characterization of a shiga toxin-encoding temperate bacteriophage of shigella sonnei. | a shiga toxin (stx)-encoding temperate bacteriophage of shigella sonnei strain cb7888 was investigated for its morphology, dna similarity, host range, and lysogenization in shigella and escherichia coli strains. phage 7888 formed plaques on a broad spectrum of shigella strains belonging to different species and serotypes, including stx-producing shigella dysenteriae type 1. with e. coli, only strains with rough lipopolysaccharide were sensitive to this phage. the phage integrated into the genome ... | 2001 | 11705937 |
| phagocytosis of bacterial pathogens: implications in the host response. | phagocytosis of bacterial pathogens is at the heart of the pathogenesis of infections. pathogens have evolved a large array of strategies to escape the deleterious effect of phagocytosis by professional phagocytes among which avoiding phagocytosis, killing the phagocytes or surviving inside them are the most 'popular' solutions. bacterial pathogens are also using induction of phagocytic entry into non-professional phagocytic cells, such as epithelial cells, as a strategy of survival and multipli ... | 2001 | 11708894 |
| [surveillance of various enteropathogenic bacteria from diarrheal cases during 1989-1999 in kobe city]. | incidence of various enteropathogenic bacteria was examined from diarrheal faecal samples that were collected from the patients of kobe city general hospital and some station hospitals (23,862), and from overseas travelers (2,855) over a period of decade (1989-1999) in kobe. a total of 1,580 strains were isolated from domestic and 331 strains from overseas travelers. the results are as follows. 1) thirteen kinds of enteropathogenic bacteria were isolated from domestic diarrheal cases (6.6%). sal ... | 2001 | 11712364 |
| identification of indicator microorganisms using a standardized pna fish method. | a standardized fluorescent in situ hybridization (fish) method using peptide nucleic acid (pna) probes for analysis of gram-negative and gram-positive bacteria, as well as yeast, has been developed. fluorescently labeled pna probes targeting specific rrna sequences of escherichia coli, pseudomonas aeruginosa, staphyloccocus aureus, salmonella were designed, as well as pna probes targeting eubacteria and eucarya. these pna probes were evaluated by pna fish using 27 bacterial and 1 yeast species, ... | 2001 | 11714518 |
| inhibitor-resistant tem-33 beta-lactamase in a shigella sonnei isolate. | 2001 | 11441825 | |
| antimicrobial susceptibilities and esbl production rates of salmonella and shigella strains in turkey. | 2001 | 11442570 | |
| clusters of shigella sonnei in men who have sex with men, british columbia, 2001. | 2001 | 11443836 | |
| drug-induced thrombotic microangiopathy: incidence, prevention and management. | the term thrombotic microangiopathy (tma) describes syndromes characterised by microangiopathic haemolytic anaemia, thrombocytopenia and variable signs of organ damage due to platelet thrombi in the microcirculation. in children, infections with shigella dysenteriae type 1 or particular strains of escherichia coli are the most common cause of tma; in adults, a variety of underlying causes have been identified, such as bacterial and viral infections, bone marrow and organ transplantation, pregnan ... | 2001 | 11444722 |
| development of a ceue-based multiplex polymerase chain reaction (pcr) assay for direct detection and differentiation of campylobacter jejuni and campylobacter coli in thailand. | a novel ceue-based multiplex pcr system was developed as an efficient diagnostics test to detect and differentiate c. jejuni and c. coli. there is no cross reactivity between c. jejuni and c. coli. in addition, the assay does not produce a positive signal from other enteric bacteria including salmonella, shigella and escherichia coli strains. campylobacter detection sensitivity was determined to be equivalent to previously reported pcr for other enteric bacteria. we also noticed that silicon dio ... | 2001 | 11448558 |
| inverse expression of p(k) and luke blood group antigens on human rbcs. | luke (lke) is a high-frequency rbc antigen, related to the p blood group system. a lke-negative phenotype is found in 1 to 2 percent of donors and may be associated with increased p(k). because p(k) and similar glycolipids are receptors for shiga toxin on cell membranes, a lke-negative phenotype could have implications for infections by shigella dysenteriae and enterohemorrhagic escherichia coli. | 2001 | 11452158 |
| an essential role for phop in mycobacterium tuberculosis virulence. | two-component regulatory proteins function in bacteria as sensory and adaptive factors in response to a wide range of environmental stimuli. some two-component systems, such as phop/phoq, control transcription of key virulence genes essential for survival in host cells in diverse intracellular bacterial pathogens, including salmonella sp., shigella sp. and yersinia sp. in this study, we have disrupted the phop gene from mycobacterium tuberculosis, which codes for a putative transcription regulat ... | 2001 | 11454210 |
| an outbreak of food poisoning among children attending an international sports event in johannesburg. | to describe an outbreak of food poisoning at a major international sports event in johannesburg and to determine the likely cause and source of the outbreak. | 2001 | 11455807 |
| sensitivity of acid-adapted and acid-shocked shigella flexneri to reduced ph achieved with acetic, lactic, and propionic acids. | survival and growth characteristics of unadapted, acid-adapted, and acid-shocked shigella flexneri 2a cells in acidified (ph 3.5 to 5.5) tryptic soy broth with 0.25% glucose (tsb) and tryptic soy agar (tsa) were determined. s. flexneri was grown at 37 degrees c for 18 h in tryptic soy broth without glucose (tsbng) (unadapted) and tsbng supplemented with 1% glucose (tsbg) (acid-adapted). cells grown in tsbng were acid shocked by adjusting 16-h cultures to ph 5.05 +/- 0.05 with lactic acid. cells ... | 2001 | 11456206 |
| molecular subtyping of shigella flexneri 3a isolates by plasmid profile analysis and pulsed-field gel electrophoresis. | twenty-two clinical isolates of shigella flexneri 3a that were obtained from stool specimens from seven outbreaks of infection in northern taiwan were subtyped and compared using plasmid profile analysis and pulsed-field gel electrophoresis (pfge). among 32 isolates, three distinct patterns were found by plasmid profile analysis and six by pfge, with three different restriction enzymes, xbai, sfii, or noti. seven pfge patterns were observed in a comparative analysis using a combination of these ... | 2001 | 11456354 |
| card4/nod1 mediates nf-kappab and jnk activation by invasive shigella flexneri. | epithelial cells are refractory to extracellular lipopolysaccharide (lps), yet when presented inside the cell, it is capable of initiating an inflammatory response. using invasive shigella flexneri to deliver lps into the cytosol, we examined how this factor, once intracellular, activates both nf-kappab and c-jun n-terminal kinase (jnk). surprisingly, the mode of activation is distinct from that induced by toll-like receptors (tlrs), which mediate lps responsiveness from the outside-in. instead, ... | 2001 | 11463746 |
| a report of an outbreak of shigellosis in a primary school in staffordshire. | this paper describes the management of an outbreak of shigellosis, reported in the national media, in a village school in staffordshire. the issues encountered by the outbreak team during the management of this incident have re-affirmed the need for public and environmental health departments to work closely with educational bodies to develop clear and consistent action plans for the management of communicable disease outbreaks. the management of communicable disease in schools, the workplace an ... | 2001 | 11464304 |
| comparative survival of enteric viruses and bacteria in atlantic ocean seawater. | the survival of escherichia coli, salmonella typhi, shigella sonnei, poliovirus type 1 and a parvovirus (minute virus of mice) was determined in seawater. seeded seawater was incubated in the laboratory at 6, 12, 20 and 28 degrees c for up to 40 d. in-situ survival studies were done seasonally (winter, spring, summer and fall) using seeded microbial dialysis equipment placed in the atlantic ocean off coastal north carolina at water depths of 3-10 m. in laboratory studies all test microbes surviv ... | 2001 | 11464742 |
| the effect of ship scrapping industry and its associated wastes on the biomass production and biodiversity of biota in in situ condition at alang. | the main pollutants for the ship scrapping industry and its associated wastes at alang are heavy metals, petroleum hydrocarbon and bacterial contaminations. the concentration of iron, manganese, cobalt, copper, zinc, lead, cadmium, nickel and mercury were 25 to 15,500% more at nearshore station of alang as compared to control site at piram. the concentration of heavy metals in the nearshore station of alang was always higher than its concentration at 10 km away. the concentration of petroleum hy ... | 2001 | 11468924 |
| a comparison of the isolation rates of salmonella and thermophilic campylobacter species after direct inoculation of media with a dilute faecal suspension and undiluted faecal material. | regardless of media used, dilution of faecal samples before direct plating may improve isolation rates and reduce subcultures by freeing organisms from the faecal mass and diminishing competing flora. despite the routine use of dilution in many laboratories, it has never been established properly whether direct or dilute inocula should be used in primary plating of faeces. a total of 3764 faecal samples was examined in four laboratories with a standardised methodology. the isolation rates, compe ... | 2001 | 11478667 |
| sensitivity and performance characteristics of a direct pcr with stool samples in comparison to conventional techniques for diagnosis of shigella and enteroinvasive escherichia coli infection in children with acute diarrhoea in calcutta, india. | as the sensitivity of the conventional techniques for identifying shigella spp. and enteroinvasive escherichia coli (eiec) causing dysentery cases is low, a pcr assay was evaluated in this study. analytical sensitivity (2 x 10(2) cfu) of the pcr technique was obtained by artificially spiking negative stool samples with a standard strain of s. flexneri type 2, then determining the detection limit. specificity (100%) of the method was determined by testing a number of known shigella and eiec strai ... | 2001 | 11478669 |
| polar targeting of shigella virulence factor icsa in enterobacteriacae and vibrio. | asymmetric localization is key to the proper function of certain prokaryotic proteins important to virulence, chemotaxis, cell division, development, motility, and adhesion. shigella icsa is localized to the old pole of the bacterium, where it mediates assembly of an actin tail inside infected mammalian cells. icsa (virg) is essential to shigella intracellular motility and virulence. we used translational fusions between portions of icsa and the green fluorescent protein (gfp) to determine the r ... | 2001 | 11481451 |
| children with first-time simple febrile seizures are at low risk of serious bacterial illness. | to describe the rates of serious bacterial illness (sbi) in children presenting to emergency departments (eds) with first-time uncomplicated febrile seizures. | 2001 | 11483452 |
| dysentery in patients infected with human immunodeficiency virus in zimbabwe: an emerging role for schistosoma mansoni and escherichia coli o157? | information on bloody diarrhoea in hiv-positives is scarce. a prospective study was therefore performed, in zimbabwe, to determine and compare the pathogens associated with bloody diarrhoea in 25 antiretroviral-naïve hiv-infected patients and 15 non-hiv-infected patients. stool cultures and colonic biopsies were performed. shigella was isolated from 18 (45%) of the subjects, schistosoma mansoni from eight (16%), escherichia coli h7:o157 from three (8%) and campylobacter jejunii from two (5%). th ... | 2001 | 11487372 |
| further studies on rpos in enterobacteria: identification of rpos in enterobacter cloacae and kluyvera cryocrescens. | rpos, the alternative sigma factor sigma(s), is important for bacterial survival under extreme conditions. many enterobacteria are opportunistic human pathogens and their ability to survive in a changing environment could be an essential step for their virulence. to determine the presence of this gene in enteric bacteria, an escherichia coli rpos probe was constructed and used to detect the presence of this gene in different species. a gene homologous to rpos was found in citrobacter amalonaticu ... | 2001 | 11491080 |
| correlation between congo red binding and contact haemolysin production in shigella species. | haemolytic strains of shigella dysenteriae type 1, shigella flexneri, shigella boydii and shigella sonnei cultured on congo red agar produced pigmented colonies (pcr+) whereas nonhaemolytic strains produced white colonies and did not bind congo red (pcr-). s. flexneri-1 haemolysin negative mutant (lacking plasmid) of haemolysin positive prototroph also did not bind congo red and produced nonpigmented colonies. among the twelve strains of shigella included in this study, the characteristics of co ... | 2001 | 11491522 |
| curved tails in polymerization-based bacterial motility. | the curved actin "comet-tail" of the bacterium listeria monocytogenes is a visually striking signature of actin polymerization-based motility. similar actin tails are associated with shigella flexneri, spotted-fever rickettsiae, the vaccinia virus, and vesicles and microspheres in related in vitro systems. we show that the torque required to produce the curvature in the tail can arise from randomly placed actin filaments pushing the bacterium or particle. we find that the curvature magnitude det ... | 2001 | 11497617 |
| predominance of serotype-specific mucosal antibody response in shigella flexneri-infected humans living in an area of endemicity. | the mucosal humoral immune response elicited following shigella flexneri infection in patients living in antananarivo districts (madagascar island) was evaluated by measuring the gut-derived, circulating immunoglobulin a (iga) antibody-secreting cells (asc) specific for the major bacterial antigen lipopolysaccharide (lps). fifty, 34, 11, and 5% of the s. flexneri-positive patients were infected with serotypes 2a, 1a, 4a, and 3a, respectively. the total number of iga asc in infected patients incr ... | 2001 | 11500390 |
| dksa is required for intercellular spread of shigella flexneri via an rpos-independent mechanism. | pathogenesis of shigella flexneri is dependent on the ability of the bacterium to invade and spread within epithelial cells. in this study, we identified dksa as a gene necessary for intercellular spread in, but not invasion of, cultured cells. the s. flexneri dksa mutant exhibited sensitivity to acid and oxidative stress, in part due to an effect of dksa on production of rpos. however, an s. flexneri rpos mutant formed plaques on tissue culture monolayers, thus excluding dksa regulation of rpos ... | 2001 | 11500451 |
| enteropathogens associated with diarrheal disease in infants of poor urban areas of porto velho, rondônia: a preliminary study. | one hundred and thirty cases of diarrhea and 43 age-matched controls, 0 to 5 years old, were studied in a pediatric outpatient unit from a poor peri urban area of porto velho, rondônia. eighty percent of diarrheal cases were observed in the groups under 2 years of age. rotavirus (19.2%) was the most frequent enteropathogen associated with diarrhea, followed by shigella flexneri (6.15%) and s. sonnei (1.5%) and salmonella sp. (6.9%). four cases of e. coli enterotoxigenic infections (3.1%), e. col ... | 2001 | 11500758 |
| the effect of temperature and low ph on survival of shigella flexneri in broth. | the survival characteristics of shigella fiexneri strain 5348 were determined in brain heart infusion broth as a function of low ph (2 to 5) and temperature (4 to 37 degrees c). stationary-phase cells were inoculated into sterile media to give initial populations of 6 to 7 log10 cfu/ml. bacterial populations were determined periodically by aerobic plate counts. survivor curves were fitted from plate count data using a two-phase linear model to derive lag times and slopes of the curves, from whic ... | 2001 | 11510653 |
| microbiological condition of ground meat retailed in monterrey, mexico. | eighty-eight samples of ground meat were randomly collected from retail stores in the metropolitan area of monterrey, mexico, and were analyzed for microbial contamination. methods were those recommended by the mexican regulation and/or the u.s. food and drug administration. over 75% of the samples contained > 10(5) total mesophilic microorganisms per g, and over 40% had >10(6) total coliforms per g. fecal coliforms were present in most samples. staphylococcus aureus was detected in 2.3% of the ... | 2001 | 11510670 |
| bacterial dna in synovial fluid cells of patients with juvenile onset spondyloarthropathies. | to identify bacterial dna in synovial fluid cells of patients with active juvenile onset spondyloarthropathy (spa). | 2001 | 11511762 |
| campylobacter jejuni--microtubule-dependent invasion. | campylobacter jejuni is the leading bacterial cause of food-borne illness worldwide and a major cause of guillain-barré paralysis. recent molecular and cellular studies of one well-characterized c. jejuni strain have begun to unravel the details of an unusual microtubule-dependent (actin-filament-independent) gut-invasion mechanism, through which at least some c. jejuni initiate disease. although responsible for causing a human dysenteric syndrome remarkably similar to that triggered by shigella ... | 2001 | 11514222 |
| cadaverine prevents the escape of shigella flexneri from the phagolysosome: a connection between bacterial dissemination and neutrophil transepithelial signaling. | shigella flexneri causes bacillary dysentery in humans by invading epithelial cells of the colon, which is characterized by an acute polymorphonuclear leukocyte (pmnl)-rich inflammation. our recent studies demonstrated that cadaverine, a polyamine, specifically acts to abrogate transepithelial signaling to pmnl induced by s. flexneri. here, insight is provided into the cellular mechanisms by which cadaverine attenuates the ability of shigella species to induce pmnl signaling. it was found that c ... | 2001 | 11517436 |
| antibiotic resistance among common bacterial enteric pathogens isolated from stool. | 2001 | 11519297 | |
| [use of bentonite clays as accumulation media for enterobacteria]. | bentonite media consisting of phosphate saline buffer and bentonite corpuscles of certain size are proposed as accumulation media for enterobacteriaceae. the "attitude" of the studied bacteria to bentonite particles of different size is selective. salmonella and shigella multiply in medium consisting of 0.001 mm particles in 1% concentration similarly as in common growth media. the growth of yersinia in medium of 0.05-mm corpuscles in 1% concentration was 3 lg higher than in common growth medium ... | 2001 | 11521600 |
| detection of escherichia coli o157:h7 and other intestinal pathogens in patients with diarrhoeal disease. | six hundred and six faeces specimens from patients with diarrhoea, aged 0->60 and living in the area of fano (italy), were examined for escherichia coli o157:h7, salmonella, shigella and thermophilic campylobacter spp. e. coli o157:h7 was not found, confirming the limited circulation of this bacterium in our country. on the other hand, salmonellae were the most frequent pathogens (5.6%), followed by campylobacters (2.3%) and shigellae (0.3%). | 2001 | 11523584 |
| lytic and lysogenic infection of diverse escherichia coli and shigella strains with a verocytotoxigenic bacteriophage. | a verocytotoxigenic bacteriophage isolated from a strain of enterohemorrhagic escherichia coli o157, into which a kanamycin resistance gene (aph3) had been inserted to inactivate the verocytotoxin gene (vt2), was used to infect enterobacteriaceae strains. a number of shigella and e. coli strains were susceptible to lysogenic infection, and a smooth e. coli isolate (o107) was also susceptible to lytic infection. the lysogenized strains included different smooth e. coli serotypes of both human and ... | 2001 | 11526041 |
| identification and structural analysis of synthetic oligosaccharides of shigella sonnei using maldi-tof ms. | maldi-tof mass spectroscopy was used for the molecular weight determination of protected synthetic oligosaccharides related to a cell surface bacterial polysaccharide. by-products containing chlorinated protecting groups caused isotopic patterns characteristic of the natural isotopic distribution of chlorine, were identified on the basis of isotopic distribution. 2,4,6-trihydroxyacetophenone (thap) as a matrix was better than 2,5-dihydroxybenzoic acid (dhb) for compounds containing chlorine, sin ... | 2001 | 11527533 |
| the making of a gradient: icsa (virg) polarity in shigella flexneri. | the generation and maintenance of subcellular organization in bacteria is critical for many cell processes and properties, including growth, structural integrity and, in pathogens, virulence. here, we investigate the mechanisms by which the virulence protein icsa (virg) is distributed on the bacterial surface to promote efficient transmission of the bacterium shigella flexneri from one host cell to another. the outer membrane protein icsa recruits host factors that result in actin filament nucle ... | 2001 | 11532149 |
| nested deletions of the srl pathogenicity island of shigella flexneri 2a. | in this study, we determined the boundaries of a 99-kb deletable element of shigella flexneri 2a strain ysh6000. the element, designated the multiple-antibiotic resistance deletable element (mrde), had recently been found to contain a 66-kb pathogenicity island (pai)-like element (designated the srl pai) which carries the shigella resistance locus (srl), encoding resistance determinants to streptomycin, ampicillin, chloramphenicol, and tetracycline. the ysh6000 mrde was found to be flanked by tw ... | 2001 | 11544215 |
| intervening sequences in rrl genes and fragmentation of 23s rrna in genera of the family enterobacteriaceae. | intervening sequences (ivss) in the rrl genes for 23s rrna are transcribed but later removed by rnase iii without religation during rna processing, leading to fragmented rrna. we examined about 240 strains of the family enterobacteriaceae for presence of ivss using pcr. no ivss were detected in strains belonging to escherichia, shigella, enterobacter, erwinia, ewingella, hafnia, kluyvera, morganella, pantoea, or serratia. previously unreported ivss were detected in klebsiella oxytoca, citrobacte ... | 2001 | 11544246 |
| changing patterns of serotypes and antimicrobial susceptibilities of shigella species isolated from children in calcutta, india. | 2001 | 11544405 | |
| apoptotic cell death in the pathogenesis of infectious diseases. | apoptosis is a physiological process critical for tissue homeostasis. it is essential for the regulation of immune responses. a series of molecules transduce apoptoic signals and induce the characteristic morphological appearances of apoptotic cells. infectious diseases modulate apoptosis and this contributes to disease pathogenesis. infection with hiv results in enhanced levels of cd4 t-lymphocyte apoptosis in both directly infected cells and in uninfected bystander cells. a variety of hiv prot ... | 2001 | 11545564 |
| [diagnostic and epidemiological significance of f-donor activity of enterobacteria strains]. | the study of the circulating strains of enteropathogenic escherichia coli (epec), shigellae and salmonellae for the presence of f-factor (the conjunction factor) was carried out. the study revealed that 85% of shigella flexneri strains 2a had conjugative (f)-factor. the proportion of such strains was 63% among epec of different serovars and 15% among salmonella enteritidis. as 63% epec strains had hemolytic activity and were found to carry f-conjugative plasmid it should be taken into considerat ... | 2001 | 11548268 |
| [effect of organic composition of humic acids on enterobacteria multiplication]. | enterobacteria have been found to be capable of active multiplication in humic acids isolated from bentonite clays containing carbohydrates, lipids and proteins. humic acids fractions have been found to be heterogeneous by their molecular weight and organic composition; consequently, they have been found to produce different influence in the multiplication of bacteria. | 2001 | 11548272 |
| distribution and structural variation of the she pathogenicity island in enteric bacterial pathogens. | shigella flexneri serotype 2a carries a chromosomal pathogenicity island (pai), termed the she pai, that has been implicated in the pathogenesis of diarrhoeal disease. the complete nucleotide sequence and genetic organisation of the she pai of s. flexneri 2a strain ysh6000t was determined recently. in the current study the distribution and structure of the she pai was investigated by pcr and southern analysis in 65 isolates of enteric pathogens including shigella spp., enterohaemorrhagic escheri ... | 2001 | 11549179 |
| actin-based motility is sufficient for bacterial membrane protrusion formation and host cell uptake. | shigella flexneri replicates in the cytoplasm of host cells, where it nucleates host cell actin filaments at one pole of the bacterial cell to form a 'comet tail' that propels the bacterium through the host's cytoplasm. to determine whether the ability to move by actin-based motility is sufficient for subsequent formation of membrane-bound protrusions and intercellular spread, we conferred the ability to nucleate actin on a heterologous bacterium, escherichia coli. previous work has shown that i ... | 2001 | 11553015 |
| molecular basis of the intracellular spreading of shigella. | 2001 | 11553531 | |
| ferric dicitrate transport system (fec) of shigella flexneri 2a ysh6000 is encoded on a novel pathogenicity island carrying multiple antibiotic resistance genes. | iron uptake systems which are critical for bacterial survival and which may play important roles in bacterial virulence are often carried on mobile elements, such as plasmids and pathogenicity islands (pais). in the present study, we identified and characterized a ferric dicitrate uptake system (fec) in shigella flexneri serotype 2a that is encoded by a novel pai termed the shigella resistance locus (srl) pai. the fec genes are transcribed in s. flexneri, and complementation of a fec deletion in ... | 2001 | 11553538 |
| release of toll-like receptor-2-activating bacterial lipoproteins in shigella flexneri culture supernatants. | shigella spp. cause dysentery, a severe form of bloody diarrhea. apoptosis, or programmed cell death, is induced during shigella infections and has been proposed to be a key event in the pathogenesis of dysentery. here, we describe a novel cytotoxic activity in the sterile-culture supernatants of shigella flexneri. an identical activity was identified in purified s. flexneri endotoxin, defined here as a mixture of lipopolysaccharide (lps) and endotoxin-associated proteins (ep). separation of end ... | 2001 | 11553567 |
| molecular evolution of large virulence plasmid in shigella clones and enteroinvasive escherichia coli. | three genes, ipgd, mxic, and mxia, all in the invasion region of the shigella virulence plasmid, were sequenced from strains representing a range of shigella serotypes and from two enteroinvasive escherichia coli (eiec) isolates. the plasmids can be classified into two relatively homogeneous sequence forms which are quite distinct. pinv a plasmids are found in shigella flexneri strains f6 and f6a, s. boydii strains b1, b4, b9, b10, b14, and b15, s. dysenteriae strains d3, d4, d6, d8, d9, d10, an ... | 2001 | 11553574 |
| locus of enterocyte effacement from citrobacter rodentium: sequence analysis and evidence for horizontal transfer among attaching and effacing pathogens. | the family of attaching and effacing (a/e) bacterial pathogens, which includes diarrheagenic enteropathogenic escherichia coli (epec) and enterohemorrhagic e. coli (ehec), remains a significant threat to human and animal health. these bacteria intimately attach to host intestinal cells, causing the effacement of brush border microvilli. the genes responsible for this phenotype are encoded in a pathogenicity island called the locus of enterocyte effacement (lee). citrobacter rodentium is the only ... | 2001 | 11553577 |
| modelling the vector pathway and infection of humans in an environmental outbreak of escherichia coli o157. | quantifying the transfer of escherichia coli o157 from the environment to humans is essential for understanding outbreaks, establishing the infectious dose of the organism and proposing safeguards. we modelled the pathogen loading shed onto a field by sheep immediately prior to a scout camp where 18 scouts and two adults were infected with e. coli o157. we estimated the dose ingested (4-24 organisms) which is in agreement with the low infective dose reported previously for this organism in food ... | 2001 | 11557142 |
| actin pedestal formation by enteropathogenic escherichia coli and intracellular motility of shigella flexneri are abolished in n-wasp-defective cells. | in mammalian cells, actin dynamics is tightly controlled through small gtpases of the rho family, wasp/scar proteins and the arp2/3 complex. we employed cre/loxp-mediated gene targeting to disrupt the ubiquitously expressed n-wasp in the mouse germline, which led to embryonic lethality. to elucidate the role of n-wasp at the cellular level, we immortalized embryonic fibroblasts and selected various n-wasp-defective cell lines. these fibroblasts showed no apparent morphological alterations and we ... | 2001 | 11559594 |
| vaccination with a shigella dna vaccine vector induces antigen-specific cd8(+) t cells and antiviral protective immunity. | a prototype shigella human immunodeficiency virus type 1 (hiv-1) gp120 dna vaccine vector was constructed and evaluated for immunogenicity in a murine model. for comparative purposes, mice were also vaccinated with a vaccinia virus-env (vaccinia-env) vector or the gp120 dna vaccine alone. enumeration of the cd8(+)-t-cell responses to gp120 after vaccination using a gamma interferon enzyme-linked spot assay revealed that a single intranasal dose of the shigella hiv-1 gp120 dna vaccine vector elic ... | 2001 | 11559798 |
| [reiter disease: clinical manifestations and diagnostic criteria]. | reiter's disease in the majority of cases has a postenteral and urogenital genesis, with idiopatic one occurring much more seldom. the clinical picture is rather polymorphous, with typical (full) urethro-oculosinovial symptom complex being encountered in 55 percent of patients, partial one--in 33 percent; in 12 percent of patients there is an extensive urethro-oculoarticular symptom complex. visceral lesions are noted as myocardiodystrophy, myocarditis, breakdown of the liver, damaged kidneys, l ... | 2001 | 11560042 |
| listeria protein acta mimics wasp family proteins: it activates filament barbed end branching by arp2/3 complex. | actin-based propulsion of the bacteria listeria and shigella mimics the forward movement of the leading edge of motile cells. while shigella harnesses the eukaryotic protein n-wasp to stimulate actin polymerization and filament branching through arp2/3 complex, the listeria surface protein acta directly activates arp2/3 complex by an unknown mechanism. here we show that the n-terminal domain of acta binds one actin monomer, in a profilin-like fashion, and arp2/3 complex and mimics the c-terminal ... | 2001 | 11560487 |
| supermolecular structure of the enteropathogenic escherichia coli type iii secretion system and its direct interaction with the espa-sheath-like structure. | enteropathogenic escherichia coli (epec) secretes several esp proteins via the type iii secretion system (secreton). espa, espb, and espd are required for translocation of the effector proteins into host cells, in which espb and espd are thought to form a pore in the host membrane. recent study has shown that espa forms a filamentous structure that assembles as a physical bridge between bacteria and host cell surfaces, which then functions as a conduit for the translocation of bacterial effector ... | 2001 | 11562461 |
| the who vaccine trial registry. | the who vaccine trial registry prospectively registers clinical vaccine studies supported by who. through december 1999, the registry includes 103 studies from 43 countries, with nearly 80% in developing countries. the registry documents an expanding research capacity, with an average of 3.9 new studies per year during 1987-1993, rising to 10.7 per year during 1994-2000. the studies concern a broad spectrum of infectious organisms, including: clostridium tetani (tetanus), dengue virus, enterotox ... | 2001 | 11567743 |
| [characteristics of urogenital and post-enterocolitis reactive arthritides]. | the immune status and profile of hla antigens of loci a and b were evaluated in 159 patients with reactive arthritis. reactive arthritis was caused by urogenital chlamydial infection in 64.2% of cases and by shigella, salmonella and yersinia enterocolitica infection in 18.9% of cases. in patients with different etiology of the disease some variations in its course and outcome, immune status as well as in the hla antigen profile were established that is indicative of genetic determination of the ... | 2001 | 11569248 |
| [bacterial pathogenicity islands]. | the information on the key pathogenicity factors of uropathogenic and enteropathogenic escherichia coli, shigella, salmonella, vibrio cholerae, yersinia, listeria and helicobacter pylori is reviewed. the analysis of data on pathogenicity "islands" and "islets" of infective agents is given. the problems of the genetic control of pathogenicity factors and the functions of pathogenicity "islands", found in infective agents, are discussed. | 2001 | 11569271 |
| microinjection and growth of bacteria in the cytosol of mammalian host cells. | most facultative intracellular bacteria replicate in specialized phagosomes after being taken up by mammalian cells. relatively few intracellular bacteria escape the phagosomal compartment with the help of cytolytic (pore-forming) proteins and replicate in the host cell cytosol. without such toxins, intracellular bacteria cannot reach this cellular compartment. to circumvent the requirement of an "escape" step, we developed a procedure allowing the efficient direct injection of bacteria into the ... | 2001 | 11572936 |
| identification of ctx-m-14 extended-spectrum beta-lactamase in clinical isolates of shigella sonnei, escherichia coli, and klebsiella pneumoniae in korea. | ctx-m-14 beta-lactamase was identified in a stool isolate of shigella sonnei and in blood isolates of escherichia coli (one isolate) and klebsiella pneumoniae (two isolates) from different parts of korea. the amino acid sequence differed by one amino acid from ctx-m-9 (ala-231--> val) and was identical to that of beta-lactamases recently found in china and japan. | 2001 | 11574608 |
| altering trends in the dominance of shigella flexneri serotypes and emergence of serologically atypical s. flexneri strains in dhaka, bangladesh. | of 469 recently isolated shigella flexneri strains, 452 agglutinated with shigella flexneri-specific monoclonal antibodies. of these, 396 could be assigned to 10 of the currently recognized 15 serotypes, with s. flexneri 2b dominating (23.2%). of the 56 untypeable strains which showed invasive properties, 17 were serologically atypical and the remaining 39 belonged to a new serotype. | 2001 | 11574611 |
| unusual molecular architecture of the yersinia pestis cytotoxin yopm: a leucine-rich repeat protein with the shortest repeating unit. | many gram-negative bacterial pathogens employ a contact-dependent (type iii) secretion system to deliver effector proteins into the cytosol of animal or plant cells. collectively, these effectors enable the bacteria to evade the immune response of the infected organism by modulating host-cell functions. yopm, a member of the leucine-rich repeat protein superfamily, is an effector produced by the bubonic plague bacterium, yersinia pestis, that is essential for virulence. here, we report crystal s ... | 2001 | 11575934 |
| isolation and structure elucidation of a new antifungal and antibacterial antibiotic produced by streptomyces sp. 201. | an antibacterial and antifungal antibiotic was isolated from the culture filtrate of streptomyces sp. 201, and its structure was determined as 2-methyl-heptyl isonicotinate by extensive use of nmr spectroscopy. the compound exhibited marked antimicrobial activity against bacillus subtilis, shigella sp., klebsiella sp., e. coli, proteus mirabilis, and the pathogenic fungi, fusarium moniliforme, f. semitectum, f. oxysporum, f. solani and rhizoctonia solani. | 2001 | 11577728 |
| hemolytic-uremic syndrome and escherichia coli o121 at a lake in connecticut, 1999. | non-o157 shiga toxin-producing escherichia coli (stec) have emerged as an important public health problem. outbreaks attributed to non-o157 stec rarely are reported. in 1999, follow-up of routine surveillance reports of children with hemolytic- uremic syndrome (hus) identified a small cluster of 3 cases of hus, all of whom had spent overlapping time in a connecticut lake community in the week before onset of symptoms. we conducted an investigation to determine the magnitude and source of the out ... | 2001 | 11581467 |
| n-wasp deficiency reveals distinct pathways for cell surface projections and microbial actin-based motility. | the wiskott-aldrich syndrome protein (wasp) family of molecules integrates upstream signalling events with changes in the actin cytoskeleton. n-wasp has been implicated both in the formation of cell-surface projections (filopodia) required for cell movement and in the actin-based motility of intracellular pathogens. to examine n-wasp function we have used homologous recombination to inactivate the gene encoding murine n-wasp. whereas n-wasp-deficient embryos survive beyond gastrulation and initi ... | 2001 | 11584271 |
| infectious diarrhea in the elderly. | infectious diarrhea is an important disease in the elderly. some basic principles have been outlined, as follows. in the elderly: infectious diarrhea is an underappreciated health problem. there is a higher mortality rate and case-fatality rate compared with younger persons. infectious diarrhea is most often associated with group settings (e.g., nursing homes and skilled nursing facilities) or antibiotic use. infectious diarrhea may be associated with abnormal immune function (i.e., immunosenesc ... | 2001 | 11586549 |
| the role of antibiotics in the treatment of infectious diarrhea. | infectious diarrhea is a significant cause of morbidity and mortality and a common complaint in clinical practice. routine empirical use of antibiotics for infectious diarrhea should be avoided because of the self-limited nature of most cases, the cost of antibiotics, and the potential to worsen the already significant problem of antibiotic resistance of enteric pathogens. for patients with severe invasive or prolonged diarrhea or who are at high risk of complications, such as the elderly, diabe ... | 2001 | 11586559 |
| influence of the yihe gene of shigella flexneri on global gene expression: on analysis using dna arrays. | inactivation of dsba (disulfide bond formation), either by an insertion (sh4, dsba::kan) or by alteration of the active site (sh42, dsba33g), renders shigella flexneri avirulent. however, sh4 and sh42 behave differently in many ways in vitro and in vivo. a gene of unknown function, yihe, up-stream and cotranscribed with dsba, is thought to differentiate sh4 and sh42 as the kan insertion may result in a truncated unstable yihe-dsba mrna in sh4. to gain insight into the function of yihe, dna array ... | 2001 | 11594757 |
| shiga toxins. | shiga toxin and shiga-like toxins belong to the group of protein toxins which have a moiety that binds to the cell surface and another enzymatically active moiety that after entry into the cytosol inhibits protein synthesis enzymatically. the toxins can also cause apoptosis by mechanisms that may be different from the effect on the protein synthesis machinery. shigella dysenteriae, some strains of escherichia coli as well as other bacteria can secrete such toxins which cause serious complication ... | 2001 | 11595626 |
| molecular mechanisms of bacteria induced apoptosis. | interaction of mammalian cells with pathogenic bacteria results in a whole variety of responses in the infected cells including internalization or phagocytosis of the bacterium, release of cytokines, secretion of defensins or production of oxygen radicals. however, recent studies pointed out that many bacteria are able to trigger apoptosis in the host cell. the induction of apoptosis upon infection results from a complex interaction of bacterial proteins with cellular proteins finally mediating ... | 2001 | 11595833 |
| sequence analysis of four shigella boydii o-antigen loci: implication for escherichia coli and shigella relationships. | shigella strains are in reality clones of escherichia coli and are believed to have emerged relatively recently (g. m. pupo, r. lan, and p. r. reeves, proc. natl. acad. sci. usa 97:10567-10572, 2000). there are 33 o-antigen forms in these shigella clones, of which 12 are identical to o antigens of other e. coli strains. we sequenced o-antigen gene clusters from shigella boydii serotypes 4, 5, 6, and 9 and also studied the o53- and o79-antigen gene clusters of e. coli, encoding o antigens identic ... | 2001 | 11598067 |
| [identification and typing of yersinia enterocolitica biotypes and serotypes isolated]. | to assess the presence of yersinia enterocolitica in otherwise healthy pigs slaughtered for human consumption. | 2001 | 11600928 |
| microbial characterization during composting of municipal solid waste. | this study investigates the prevailing physico-chemical conditions and microbial community; mesophilic bacteria, yeasts and filamentous fungi, bacterial spores, salmonella and shigella as well as faecal indicator bacteria: total coliforms, faecal coliforms and faecal streptococci, present in a compost of municipal solid waste. investigations were conducted in a semi-industrial pilot plant using a moderate aeration during the composting process. our results showed that: (i) auto-sterilization ind ... | 2001 | 11601546 |
| inhibitory activity of honey against foodborne pathogens as influenced by the presence of hydrogen peroxide and level of antioxidant power. | antimicrobial activity of honey has been attributed to hydrogen peroxide, which is produced by naturally occurring glucose oxidase, and phenolic compounds, although lethality of and inhibition by these and other components against microorganisms vary greatly, depending on the floral source of nectar. this study was undertaken to compare honeys from six floral sources for their inhibitory activity against escherichia coli o157:h7, salmonella typhimurium, shigella sonnei, listeria monocytogenes, s ... | 2001 | 11603859 |
| transfer of eukaryotic expression plasmids to mammalian host cells by bacterial carriers. | the concept of transkingom transfer of dna from bacteria to other organisms has recently been extended to include eukaryotic host cells. intracellular bacteria have been shown to transfer eukaryotic expression plasmids to mammalian host cells in vitro and in vivo. this can be used to induce immune responses towards protein antigens encoded by the plasmid, to complement genetic defects or even to direct the production of proteins in appropriate organs. the ease of generating such vehicles makes t ... | 2001 | 11604322 |
| epidemiology, clinical course and impact on hospitalization costs of acute diarrhea among hospitalized children in athens, greece. | the aim of this study was to describe the etiology, morbidity and hospitalization costs associated with acute diarrhea among hospitalized children in greece. during 1999, 294 hospitalized children (median age 1 y) with acute diarrhea were prospectively studied. bacterial and viral enteropathogens were detected in 100 (34%) and 37 (12.5%) patients, respectively; 17 (6%) patients had mixed infections. isolated agents included salmonella spp. (43 patients; 15%), rotavirus (32; 11%), campylobacter s ... | 2001 | 11669226 |
| shigella flexneri luxs quorum-sensing system modulates virb expression but is not essential for virulence. | quorum-sensing systems regulate the expression of virulence factors in a wide variety of plant and animal pathogens, including members of the enterobacteriaceae. studies of shigella virulence gene expression have demonstrated that maximal expression of genes encoding the type iii secretion system and its substrates and maximal activity of this virulence organelle occur at high cell density. in these studies, we demonstrate that the expression of ipa, mxi, and spa invasion operons is maximal in s ... | 2001 | 11119484 |
| identification of functional regions within invasion plasmid antigen c (ipac) of shigella flexneri. | shigella flexneri causes bacillary dysentery with symptoms resulting from the inflammation that accompanies bacterial entry into the cells of the colonic epithelium. the effectors of s. flexneri invasion are the ipa proteins, particularly ipab and ipac, which are secreted at the host-pathogen interface following bacterial contact with a host cell. of the purified ipa proteins, only ipac has been shown to possess quantifiable in vitro activities that are related to cellular invasion. in this stud ... | 2001 | 11123692 |
| rapid detection, identification, and enumeration of escherichia coli cells in municipal water by chemiluminescent in situ hybridization. | a new chemiluminescent in situ hybridization (cish) method provides simultaneous detection, identification, and enumeration of culturable escherichia coli cells in 100 ml of municipal water within one working day. following filtration and 5 h of growth on tryptic soy agar at 35 degrees c, individual microcolonies of e. coli were detected directly on a 47-mm-diameter membrane filter using soybean peroxidase-labeled peptide nucleic acid (pna) probes targeting a species-specific sequence in e. coli ... | 2001 | 11133438 |
| inactivation of gram-negative bacteria by lysozyme, denatured lysozyme, and lysozyme-derived peptides under high hydrostatic pressure. | we have studied the inactivation of six gram-negative bacteria (escherichia coli, pseudomonas fluorescens, salmonella enterica serovar typhimurium, salmonella enteritidis, shigella sonnei, and shigella flexneri) by high hydrostatic pressure treatment in the presence of hen egg-white lysozyme, partially or completely denatured lysozyme, or a synthetic cationic peptide derived from either hen egg white or coliphage t4 lysozyme. none of these compounds had a bactericidal or bacteriostatic effect on ... | 2001 | 11133464 |
| resistance to antimicrobial agents in mediterranean countries. | 2001 | 11137644 | |
| conserved regulatory elements of the promoter sequence of the gene rpoh of enteric bacteria. | the rpoh regulatory region of different members of the enteric bacteria family was sequenced or downloaded from genbank and compared. in addition, the transcriptional start sites of rpoh of yersinia frederiksenii and proteus mirabilis, two distant members of this family, were determined. sequences similar to the sigma(70) promoters p1, p4 and p5, to the sigma(e) promoter p3 and to boxes dnaa1, dnaa2, camp receptor protein (crp) boxes crp1, crp2 and box cytr present in escherichia coli k12, were ... | 2001 | 11139607 |
| surfing pathogens and the lessons learned for actin polymerization. | a number of unrelated bacterial species as well as vaccinia virus (ab)use the process of actin polymerization to facilitate and enhance their infection cycle. studies into the mechanism by which these pathogens hijack and control the actin cytoskeleton have provided many interesting insights into the regulation of actin polymerization in migrating cells. this review focuses on what we have learnt from the actin-based motilities of listeria, shigella and vaccinia and discusses what we would still ... | 2001 | 11146296 |
| a colony blot immunoassay to detect enteroinvasive escherichia coli and shigella in water samples. | the aim of the study was to develop a colony blot immunoassay to detect shigella and enteroinvasive escherichia coli (eiec) in water. | 2001 | 11168726 |
| structure and composition of the shigella flexneri "needle complex", a part of its type iii secreton. | type iii secretion systems (ttsss or secretons), essential virulence determinants of many gram-negative bacteria, serve to translocate proteins directly from the bacteria into the host cytoplasm. electron microscopy (em) indicates that the ttsss of shigella flexneri are composed of: (1) an external needle; (2) a transmembrane domain; and (3) a cytoplasmic bulb. em analysis of purified and negatively stained parts 1, 2 and a portion of 3 of the ttss, together termed the "needle complex" (nc), pro ... | 2001 | 11169106 |
| secretion of predicted inc proteins of chlamydia pneumoniae by a heterologous type iii machinery. | chlamydia spp. are strictly intracellular pathogens that grow inside a vacuole, called an inclusion. they possess genes encoding proteins homologous to components of type iii secretion machineries, which, in other bacterial pathogens, are involved in delivery of bacterial proteins within or through the membrane of eukaryotic host cells. inc proteins are chlamydial proteins that are associated with the inclusion membrane and are characterized by the presence of a large hydrophobic domain in their ... | 2001 | 11169118 |
| rational protocols for testing faeces in the investigation of sporadic hospital-acquired diarrhoea. | many recent studies have demonstrated that routine examination of faeces for conventional enteric pathogens such as salmonella, shigella, campylobacter and parasites in patients who develop sporadic hospital-acquired diarrhoea is unnecessary and wasteful. in this paper the advantages and disadvantages of a restricted testing protocol in patients with hospital-acquired diarrhoea are reviewed. practical issues for safe implementation of such a protocol are also discussed. | 2001 | 11170768 |
| microbes and microbial toxins: paradigms for microbial-mucosal interactions iii. shigellosis: from symptoms to molecular pathogenesis. | interaction of shigella flexneri with epithelial cells includes contact of bacteria with the cell surface and release of ipa proteins through a specialized type iii secreton. a complex signaling process involving activation of small gtpases of the rho family and c-src causes major rearrangements of the subcortical cytoskeleton, thereby allowing bacterial entry by macropinocytosis. after entry, shigellae escape to the cell cytoplasm and initiate intracytoplasmic movement through polar nucleation ... | 2001 | 11171613 |
| the insect endosymbiont sodalis glossinidius utilizes a type iii secretion system for cell invasion. | sodalis glossinidius is a maternally transmitted secondary endosymbiont residing intracellularly in tissues of the tsetse flies, glossina spp. in this study, we have used tn5 mutagenesis and a negative selection procedure to derive a s. glossinidius mutant that is incapable of invading insect cells in vitro and is aposymbiotic when microinjected into tsetse. this mutant strain harbors tn5 integrated into a chromosomal gene sharing high sequence identity with a type iii secretion system invasion ... | 2001 | 11172045 |
| salmonella-induced cell death: apoptosis, necrosis or programmed cell death? | over the past several years, it has become apparent that enteropathogens activate cell death programs. for salmonella and shigella species, the induction of cell death is required for pathogenesis, and the mechanisms by which these bacteria induce cell death is an area of intense investigation. although initial studies suggested that salmonella induce cell death through an apoptotic pathway, recent studies demonstrate that cell death occurs through a unique caspase 1-dependent mechanism. | 2001 | 11173244 |
| shigellae control the gates of ll. | 2001 | 11175842 | |
| downregulation of bactericidal peptides in enteric infections: a novel immune escape mechanism with bacterial dna as a potential regulator. | antibacterial peptides are active defense components of innate immunity. several studies confirm their importance at epithelial surfaces as immediate barrier effectors in preventing infection. here we report that early in shigella spp. infections, expression of the antibacterial peptides ll-37 and human beta-defensin-1 is reduced or turned off. the downregulation is detected in biopsies from patients with bacillary dysenteries and in shigella- infected cell cultures of epithelial and monocyte or ... | 2001 | 11175848 |
| a new target for shigellosis: rational design and crystallographic studies of inhibitors of trna-guanine transglycosylase. | eubacterial trna-guanine transglycosylase (tgt) is involved in the hyper-modification of cognate trnas leading to the exchange of g34 at the wobble position in the anticodon loop by preq1 (2-amino-5-(aminomethyl)pyrrolo[2,3-d]pyrimidin-4(3h)-one) as part of the biosynthesis of queuine (q). mutation of the tgt gene in shigella flexneri results in a significant loss of pathogenicity of the bacterium, revealing tgt as a new target for the design of potent drugs against shigellosis. the x-ray struct ... | 2001 | 11178905 |