Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| shigella invasion of macrophage requires the insertion of ipac into the host plasma membrane. functional analysis of ipac. | shigella infects residential macrophages via the m cell entry, after which the pathogen induces macrophage cell death. the bacterial strategy of macrophage infection, however, remains largely speculative. wild type shigella flexneri (ysh6000) invaded macrophages more efficiently than the noninvasive mutants, where ysh6000 induced large scale lamellipodial extension including ruffle formation around the bacteria. when macrophages were infected with the noninvasive ipac mutant, the invasiveness an ... | 2001 | 11413141 |
| shigella protein ipah(9.8) is secreted from bacteria within mammalian cells and transported to the nucleus. | various pathogenic bacteria such as shigella deliver effector proteins into mammalian cells via the type iii secretion system. the delivered shigella effectors have been shown to variously affect host functions required for efficient bacterial internalization into the cells. in the present study, we investigated the ipah proteins for their ability to be secreted via the type iii secretion system and their fate in mammalian cells. upon incubation in a medium containing congo red, the bacteria sec ... | 2001 | 11418613 |
| analysis of the o-antigen chain length distribution during extracellular and intracellular growth of shigella flexneri. | this study has established that there were no changes in the general structure of lps of shigella flexneri m90t either when the bacteria grew free in the cytoplasm of the eucaryotic host cell or during extracellular growth in liquid lb medium at 37 degrees c. in both cases there was a similar bi-modal o-antigen chain length distribution with the mean modal values between 1 and 2, and between 11 and 14 subunits. this suggests that the intracellular localization is not a significant stimulus perce ... | 2001 | 11427033 |
| characterization of cryptic flagellin genes in shigella boydii and shigella dysenteriae. | flagellin (flic) genes of 12 shigella boydii and five shigella dysenteriae strains were characterized. though these strains are nonmotile, the cryptic flicsb gene, cloned from s. boydii strain c3, is functional for expression of flagellin. it consists of 1,704 bp, and encodes 568 amino acid residues (57,918 da). the flicsd gene from s. dysenteriae strain 16 consists of 1,650 bp encoding 549 amino acid residues (57,591 da) and contains an is1 element inserted in its 3' end. the two genes are comp ... | 2001 | 11434456 |
| regulation of virulence gene expression in shigella flexneri, a facultative intracellular pathogen. | shigella flexneri and its close relatives are facultative intracellular pathogens of humans and are the etiological agents of bacillary dysentery. these bacteria secrete proteins that enable them to enter human epithelial cells via an elaborate and fascinating cell biology. this behaviour depends on a complicated regulon of virulence genes, whose expression is controlled in response to a multiplicity of environmental signals. this review describes and attempts to interpret these gene control mec ... | 2001 | 11437343 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| gene cloning and characterization of alanine racemases from shigella dysenteriae, shigella boydii, shigella flexneri, and shigella sonnei. | alanine racemase genes (alr) from shigella dysenteriae, shigella boydii, shigella flexneri, and shigella sonnei were cloned and expressed in escherichia coli jm109. all genes encoded a polypeptide of 359 amino acids, and showed more than 99% sequence identities with each other. in particular, the s. dysenteriae alr was identical with the s. flexneri alr. differences in the amino acid sequences between the four shigella enzymes were only two residues: gly138 in s. dysenteriae and s. flexneri (glu ... | 2001 | 11676496 |
| inactivation of dsba alters the behaviour of shigella flexneri towards murine and human-derived macrophage-like cells. | the mutants of shigella flexneri, sh4 (dsba::kan) and sh42 (dsba33g), behave differently towards murine and human-derived macrophage-like cells in vitro. sh4 was trapped in the phagocytic vacuoles of the murine j774 cells as evidenced by its colony forming units plus and minus chloroquine exposure in a gentamicin protection assay, and by light and transmission electron microscopy (tem). sh42, similar to the wild-type m90ts, was able to escape from the vacuoles and kill host cells presumably by i ... | 2001 | 11682183 |
| salmonella, shigella and growth potential of other food-borne pathogens in ethiopian street vended foods. | to evaluate the bacteriological safety of food items sold by street vendors with regard to salmonella and shigella and to assess the growth potential of some foodborne pathogens in some street foods. | 2001 | 12219962 |
| epidemiological applications: a case report of a village epidemic of gastroenteritis. | this is a case report of an epidemic of gastroenteritis which was investigated and controlled by epidemiological methods only, before laboratory investigations could be done to confirm the original epidemiological conclusions--from contaminated home made ice-cubes. the case and process are reported in order to encourage similar uses of epidemiology by field public health practitioners, especially within the district or primary health care systems and particularly in places where laboratory suppo ... | 2001 | 12017811 |
| death from multi-resistant shigellosis in fiji islands. | death from shigellosis is rare in developed countries, however it causes over a million deaths in developing countries worldwide annually. death from shigellosis is rare in fiji. however, the global problem of emerging multidrug resistance raises some issues about the management of shigellosis in this country. within fiji, shigella is a notifiable disease. the fiji ministry of health recorded 68 cases of shigella in 1996, 173 cases in 1997 and 334 cases in 1998 (no data available for 1999). ther ... | 2001 | 12017845 |
| the infrared spectroscopic gram stain. | the attenuated total reflectance (atr) spectra of bacterial colonies were obtained in situ, without their removal from the agar growth media using the infrared microscope. principal components regression (pcr) analysis was used to obtain a measure of the differentiating potential of the atr spectra obtained on two standard sets consisting of 31 and 44 species, respectively, grown on trypticase soy agar. a quantitative response value of +1 was assigned to gram positive species and -1 was assigned ... | 2001 | 11936876 |
| synthesis and antimicrobial activity of some 1,2,4-triazole-3-mercaptoacetic acid derivatives. | ethyl 5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetate (2), 5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetic acid hydrazide (3) and a series of new n-alkylidene/arylidene-5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetic acid hydrazides (4a-f) were synthesized and evaluated for in vitro antibacterial activity against staphylococcus aureus atcc 6538. staphylococcus epidermidis atcc 12228, klebsiella pneumoniae atcc 4352, pseudomonas aeruginosa atcc 1539, escherichia coli atcc 8739, shige ... | 2001 | 11829115 |
| synthesis and evaluation of antibacterial activity of some 2-[[alpha-(4-substituted benzoyloxy)-alpha-phenylacetyl or methylacetyl]amino]-5-(4-methoxyphenyl)- 1,3,4-oxadiazoles. | in this study, a new series of 1-[[alpha-(4-substitutedbenzoyloxy)-alpha-phenylacetyl or methylacetyl]amino]-5-(4-methoxyphenyl)-1,3,4-oxadiazoles were obtained by condensation of 2-[(alpha-chloro-alpha-phenylacetyl or alpha-bromopropionyl)amino]-5-(4-methoxyphenyl)1,3,4-oxadiazoles with sodium salts of 4-substituted benzoic acids. structures of the compounds were assigned on the basis of spectral data (uv, ir, 1h nmr, el ms) and elemental analyses. the antibacterial activities of the novel comp ... | 2001 | 11829119 |
| protective role of human lactoferrin against invasion of shigella flexneri m90t. | lactoferrin is an iron-binding protein found in human mucosal secretions such as milk. a variety of functions have been ascribed to this protein, it appears to contribute to antimicrobial host defense. still its overall physiological role remains to be defined. we sought to study the role of recombinant human lactoferrin (rhlf) in shigella infection. invasion of epithelial cells is essential to the development of bacillary dysentery. shigella flexneri 5 m90t, a virulent strain, was evaluated in ... | 2001 | 11787716 |
| neonatal shigellosis. | 2001 | 11794928 | |
| [isolation of provisional serovars of shigella in diarrheal cases of tourists]. | twenty-four shigella strains of provisional serovars were isolated from travellers with diarrhea during 1993-2000 at osaka airport- and kansai airport-quarantine station. the outline of these cases were as follows. 1) the provisional serovars of these strains (number of cases) were s. dysenteriae 93-119 (2), s. dysenteriae 204/96 (4), s. dysenteriae i9809-73 (4), s. flexneri 88-893 (9), and s. boydii e16553 (5). 2) symptoms of these cases were diarrhea, abdominal pain, fever, and vomiting. the r ... | 2001 | 11806136 |
| shigella septicaemia in adults: report of two cases and mini-review. | we report 2 cases of shigella septicaemia in adult patients. | 2001 | 11817302 |
| expression of colonization factor antigen i of enterotoxigenic escherichia coli in shigella flexneri 2a t32. | a host-plasmid lethal balancing system was constructed based on asd gene in an avirulent strain of s.flexneri to express colonization factor antigen i(cfa-i) of enterotoxigenic escherichia coli.the results of western blotting suggested that avirulant strain of s.flexneri fwl01 expressed cfa-i steadily. examination of negatively-stained preparation of cultures by electron microscopy showed that s.flexneri fwl01 carrying the plasmid pzhy21 had thick pili on its surface. antibodies against cfa-i we ... | 2001 | 12050785 |
| survivability of shigella dysenteriae type 1 & s. flexneri 2a in laboratory conditions simulating aquatic environment. | information about the duration of survival of shigellae in water is speculative. the present study was undertaken to assess the duration of survival of shigella dysenteriae type 1 and s. flexneri type 2a in the laboratory conditions simulating the aquatic environment, their invasive property and the association of different physico-chemical parameters in the survival process. | 2001 | 12040763 |
| antimicrobial resistance of shigella spp isolated from diarrheal patients between 1989 and 1998 in vietnam. | shigellosis is an important cause of infectious diarrhea in vietnam, caused mainly by shigella flexneri. this study provides for the first time in the international literature, data on the development of antimicrobial resistance in shigella between 1988 to 1998, including data reported to the national program for surveillance of antimicrobial resistance (npsar). our studies show that about 80% of the shigella strains tested were resistant to ampicillin, chloramphenicol, oxytetracycline, trimetho ... | 2001 | 12041563 |
| [investigation of a shigellosis outbreak in a rural zone of senegal]. | the investigation of this outbreak took place in niakhar (ird project study area), a rural area located 150 km east of dakar. covering 30 villages, with a population of about 30,000 inhabitants, the area has been under demographic and epidemiological surveillance. in 1999, the surveillance allowed 973 cases of shigellosis to be recorded out of 1,751 cases of dysenteric diarrhoeas. the outbreak reached a peak during the raining season (73% of the cases in september and october). all the villages ... | 2001 | 11861195 |
| [role of shigella flexneri type-specific antigen in bacterial resistance to oxidative stressor]. | lac+ type- s. flexneri 1298 1a and s. flexneri 1338 1b hybrids has been obtained in the crosses of shigella strains with escherichia coli k-12 hfr c. the detection of in vitro survive of the bacteria of genetically linked pair strains, differing in type specific antigen synthesis is presented. the more sensitive of lac+ type- hybrids to the treatment by hydrogen peroxide of concentration 205 mm in comparison with the parent s. flexneri strains possesses the type specific antigen synthesis was sh ... | 2000 | 12712519 |
| [gena types of shigella enterotoxins of s. flexneri 2a]. | to identify homogenous clones of s. flexneri 2a, using gene distribution polymorphism of shigella enterotoxin 1 (set 1) and shigella enterotoxin 2 (set 2) in a shigellosis outbreak caused by s. flexneri 2a. | 2000 | 11860800 |
| differentiation of shigella strains by plasmid profile analysis, serotyping and phage typing. | ninety-one shigella flexneri and 29 shigella sonnei strains isolated during 1994 from sporadic cases of shigellosis and healthy carriers were analyzed for plasmid profile in order to compare the discriminating ability of this method with that of serotyping and phage typing. our study revealed 10 plasmid profiles (pp) among s. sonnei strains. a total of 26 out of 29 (89%) s. sonnei isolates could be placed into two phage types (type 1 and 20) comprising four pp for phage type 1 and seven pp for t ... | 2000 | 11845469 |
| production and characterization of a new monoclonal antibody against neisseria meningitidis: study of the cross-reactivity with different bacterial genera. | we have generated a hybridoma cell line which produces an 8c7br1 clone of the igm antibody isotype. it recognizes the 50-, 65-, and 60-kda antigens and is reactive with strains of n. meningitidis in the 98% of local neisseria genera by dot-elisa assays. two percent of the strains of n. meningitidis b do not present reactivity with the 8c7br1 monoclonal antibody (mab). the antibody reacted against n. meningitidis of serogroups a, b, c, x, y, z, and different serotypes and subtypes of n. meningiti ... | 2000 | 11152396 |
| invasive shigella flexneri activates nf-kappa b through a lipopolysaccharide-dependent innate intracellular response and leads to il-8 expression in epithelial cells. | the pathogenesis of shigella flexneri infection centers on the ability of this organism to invade epithelial cells and initiate an intense inflammatory reaction. because nf-kappa b is an important transcriptional regulator of genes involved in inflammation, we investigated the role of this transcription factor during s. flexneri infection of epithelial cells. infection of hela cells with invasive s. flexneri induced nf-kappa b dna-binding activity; noninvasive s. flexneri strains did not lead to ... | 2000 | 10878365 |
| amino acid substitutions in a variant of imp-1 metallo-beta-lactamase. | in the course of surveying for the carbapenem-hydrolyzing metallo-beta-lactamase gene bla(imp) in pathogenic bacteria by the pcr method, we detected a gene encoding a variant metallo-beta-lactamase, designated imp-3, which differed from imp-1 by having low hydrolyzing activity for penicillins and carbapenems. pcr product direct sequencing of a 2.2-kb segment revealed that the gene bla(imp-3) was located on a cassette inserted within a class i integron in the pms390 plasmid. the 741-bp nucleotide ... | 2000 | 10898670 |
| beta-lactamases in shigella flexneri isolates from hong kong and shanghai and a novel oxa-1-like beta-lactamase, oxa-30. | ninety-one ampicillin-resistant shigella flexneri strains from hong kong and shanghai were studied for production of beta-lactamases. tem-1-like and oxa-1-like enzymes were identified in 21 and 79% of the strains, respectively, by isoelectric focusing (ief). no difference in the pattern of beta-lactamase production was found between strains from hong kong and shanghai. four ribotypes were detected. over 88% of oxa-producing strains had the same ribotype. all tem-1-like strains harbored a plasmid ... | 2000 | 10898672 |
| a macrophage invasion mechanism for mycobacteria implicating the extracellular domain of cd43. | we studied the role of cd43 (leukosialin/sialophorin), the negatively charged sialoglycoprotein of leukocytes, in the binding of mycobacteria to host cells. cd43-transfected hela cells bound mycobacterium avium, but not salmonella typhimurium or shigella flexneri. quantitative bacteriology showed that macrophages (m(phi)) from wild-type mice (cd43(+/+)) bound m. avium, mycobacterium bovis (bacillus calmette-guérin), and mycobacterium tuberculosis (strain h37rv), whereas m(phi) from cd43 knockout ... | 2000 | 10899905 |
| blockade of cd14 increases shigella-mediated invasion and tissue destruction. | shigella is a diarrheal pathogen that causes disease through invasion of the large intestinal mucosa. the endotoxin of the invading bacterium may play a key role in the disease process by causing inflammation and tissue injury during infection. earlier studies have shown that various animal species lacking functional cd14 were protected against endotoxin-mediated shock. rabbits experimentally infected with shigella were used to test the hypothesis that blockade of endotoxin-induced cell activati ... | 2000 | 10706713 |
| the development of a facs-based strategy for the isolation of shigella flexneri mutants that are deficient in intercellular spread. | in the disease course of bacillary dysentery, pathogenic shigella flexneri invade colonic epithelial cells and spread both within and between host cells. the ability to spread intercellularly allows the organism to infect an entire epithelial layer without significant contact with the extracellular milieu. using fluorescence activated cell sorter (facs)-based technology, we developed a rapid and powerful selection strategy for the isolation of s. flexneri mutants that are unable to spread from c ... | 2000 | 10712681 |
| deltaguaba attenuated shigella flexneri 2a strain cvd 1204 as a shigella vaccine and as a live mucosal delivery system for fragment c of tetanus toxin. | the deltaguaba shigella flexneri 2a vaccine candidate, cvd 1204, was evaluated as a delivery system for the non-toxic c-terminal of tetanus toxin (fragment c), either as a polypeptide expressed in the bacteria or as a dna vaccine. cvd 1204 was transformed with plasmid ptetnir15 which encodes the fragment c gene (tetc) under the control of the inducible prokaryotic nir15 promoter or a dna vaccine plasmid pcdna3tetc which encodes tetc under the eukaryotic hcmv promoter. guinea pigs immunised intra ... | 2000 | 10717338 |
| the siga gene which is borne on the she pathogenicity island of shigella flexneri 2a encodes an exported cytopathic protease involved in intestinal fluid accumulation. | in this study, the siga gene situated on the she pathogenicity island of shigella flexneri 2a was cloned and characterized. sequence analysis showed that siga encodes a 139.6-kda protein which belongs to the spate (serine protease autotransporters of enterobacteriaceae) subfamily of autotransporter proteins. the demonstration that siga is autonomously secreted from the cell to yield a 103-kda processed form and possesses a conserved c-terminal domain for export from the cell were consistent with ... | 2000 | 10768931 |
| the shda gene is restricted to serotypes of salmonella enterica subspecies i and contributes to efficient and prolonged fecal shedding. | little is known about factors which enable salmonella serotypes to circulate within populations of livestock and domestic fowl. we have identified a dna region which is present in salmonella serotypes commonly isolated from livestock and domestic fowl (s. enterica subspecies i) but absent from reptile-associated salmonella serotypes (s. bongori and s. enterica subspecies ii to vii). this dna region was cloned from salmonella serotype typhimurium and sequence analysis revealed the presence of a 6 ... | 2000 | 10768965 |
| characterization of the genes encoding the shea haemolysin in escherichia coli o157:h7 and shigella flexneri 2a. | 2000 | 10865950 | |
| profilin is required for sustaining efficient intra- and intercellular spreading of shigella flexneri. | the ability of shigella to mediate actin-based motility within the host cell is a prominent pathogenic feature of bacillary dysentery. the ability is dependent on the interaction of virg with neural wiskott-aldrich syndrome protein (n-wasp), which in turn mediates recruitment of arp2/3 complex and several actin-related proteins. in the present study, we show that profilin i is essential to the rapid movement of shigella in epithelial cells, for which the capacity of profilin to interact with g-a ... | 2000 | 10867004 |
| synthesis and antimicrobial activity of 4-carbethoxymethyl-2-[(alpha-haloacyl)amino] thiazoles and 5-nonsubstituted/substituted 2-[(4-carbethoxymethylthiazol-2-yl)imino]-4-thiazolidinones. | 4-carbethoxymethyl-2-[(chloroacetyl/alpha-chloropropionyl/al pha- bromobutyryl/alpha-chloro-(alpha-phenylacetyl)amino]thiazoles (i-iv) were synthesized by reacting 4-carbethoxymethyl-2-aminothiazole with chloroacetyl chloride, alpha-chloropropionyl chloride, alpha-bromobutyryl bromide and alpha-chloro-alpha-phenylacetyl chloride, respectively. furthermore, i-iv were refluxed with ammonium thiocyanate to give 2-[(4-carbethoxymethylthiazol-2-yl)imino]-4-thiazolidinones (v-viii). v was refluxed wit ... | 2000 | 10918953 |
| supramolecular structure of the shigella type iii secretion machinery: the needle part is changeable in length and essential for delivery of effectors. | we investigated the supramolecular structure of the shigella: type iii secretion machinery including its major components. our results indicated that the machinery was composed of needle and basal parts with respective lengths of 45.4 +/- 3.3 and 31.6 +/- 0.3 nm, and contained mxid, mxig, mxij and mxih. spa47, encoding a putative f(1)-type atpase, was required for the secretion of effector proteins via the type iii system and was involved in the formation of the needle. the spa47 mutant produced ... | 2000 | 10921870 |
| attenuated shigella flexneri 2a vaccine strain cvd 1204 expressing colonization factor antigen i and mutant heat-labile enterotoxin of enterotoxigenic escherichia coli. | a multivalent live oral vaccine against both shigella spp. and enterotoxigenic escherichia coli (etec) is being developed based on the hypothesis that protection can be achieved if attenuated shigellae express etec fimbrial colonization factors and genetically detoxified heat-labile toxin from a human etec isolate (lth). two detoxified derivatives of lth, lthk63 and lthr72, were engineered by substitution-serine to lysine at residue 63, or lysine to arginine at residue 72. the genes encoding the ... | 2000 | 10948101 |
| diversion of cytoskeletal processes by shigella during invasion of epithelial cells. | shigella, the causative agent of bacillar dysentery, invades colonic epithelial cells and moves intracellularly to spread from cell to cell. the processes of shigella entry, determined by the ipa proteins, and of actin-based motility, dependent on the icsa/virg protein, represent different levels of bacterial manipulation of the cell cytoskeleton. | 2000 | 10955962 |
| characterization of the interaction of ipab and ipad, proteins required for entry of shigella flexneri into epithelial cells, with a lipid membrane. | entry of shigella flexneri into epithelial cells and lysis of the phagosome involve the ipab, ipac, and ipad proteins, which are secreted by type iii secretion machinery. we report here the purification of ipab and ipad and the characterization of their lipid-binding properties as a function of ph. the interaction of ipab with the membrane was quite independent of the ph whereas that of ipad took place only at low ph. to support the data obtained with the purified proteins, we designed a system ... | 2000 | 10971588 |
| galanin-1 receptor up-regulation mediates the excess colonic fluid production caused by infection with enteric pathogens. | galanin is widely distributed in enteric nerve terminals lining the gastrointestinal tract. we previously showed that pathogenic escherichia coli, but not normal commensal organisms, increase galanin-1 receptor expression by epithelial cells lining the colon (i.e., colonocytes). when present, galanin-1 receptor activation by ligand causes colonocyte cl- secretion. we herein demonstrate that disparate pathogens including salmonella typhimurium and shigella flexerii also increase colonocyte galani ... | 2000 | 10973327 |
| treatment of bacillary dysentery in vietnamese children: two doses of ofloxacin versus 5-days nalidixic acid. | nalidixic acid (na: 55 mg/kg daily for 5 days) is the recommended treatment for uncomplicated bacillary dysentery in areas where multidrug-resistant shigella are prevalent. an open randomized comparison of this na regimen with 2 doses of ofloxacin (total 15 mg/kg) was conducted in 1995/96 in 135 vietnamese children with fever and bloody diarrhoea. sixty-six children with a bacterial pathogen isolated were eligible for analysis. of the 63 shigella isolates, 39 (62%) were resistant to multiple ant ... | 2000 | 10975012 |
| myosin light chain kinase plays an essential role in s. flexneri dissemination. | shigella flexneri, the causitive agent of bacillary dysentery, has been shown to disseminate in colonic epithelial cells via protrusions that extend from infected cells and are endocytosed by adjacent cells. this phenomenon occurs in the region of the eukaryotic cell's adherens junctions and is inhibited by pharmacological reagents or host cell mutations that completely disrupt the junctional complex. in this study, inhibitors of the myosin light chain kinase (mlck) were shown to dramatically de ... | 2000 | 10984429 |
| tripeptidyl peptidase ii promotes maturation of caspase-1 in shigella flexneri-induced macrophage apoptosis. | the invasive enteropathogenic bacterium shigella flexneri activates apoptosis in macrophages. shigella-induced apoptosis requires caspase-1. we demonstrate here that tripeptidyl peptidase ii (tppii), a cytoplasmic, high-molecular-weight protease, participates in the apoptotic pathway triggered by shigella. the tppii inhibitor ala-ala-phe-chloromethylketone (aaf-cmk) and clasto-lactacystin beta-lactone (lactacystin), an inhibitor of both tppii and the proteasome, protected macrophages from shigel ... | 2000 | 10992446 |
| triphenyltin salicylate-antimicrobial effect and resistance--the pyrophosphatase connection. | the effect of triphenyltin salicylate (tps) was tested against six bacteria, escherichia coli, staphylococcus aureus, shigella flexneri, pseudomonas aeruginosa, klebsiella pneumoniae and salmonella typhi and five fungi, aspergillus flavus, aspergillus fumigatus, aspergillus niger, rhodotorula spp. and saccharomyces spp. sensitivity tests were determined with 5-500 microg/ml of tps. all organisms were sensitive to the compound except klebsiella pneumoniae, pseudomonas aeruginosa, rhodotorula spp. ... | 2000 | 10995071 |
| genetic analysis of escherichia coli k1 gastrointestinal colonization. | strains of escherichia coli expressing the k1 polysaccharide capsule colonize the large intestine of newborn infants, and are the leading cause of gram-negative septicaemia and meningitis in the neonatal period. we used signature-tagged mutagenesis (stm) to identify genes that e. coli k1 requires to colonize the gastrointestinal (gi) tract. a total of 2140 mtn5 mutants was screened for their capacity to colonize the gi tract of infant rats, and 16 colonization defective mutants were identified. ... | 2000 | 10998163 |
| improved template preparation for pcr-based assays for detection of food-borne bacterial pathogens. | shigella flexneri, salmonella enterica serotype typhimurium, and listeria monocytogenes were applied to fta filters, and the filters were used directly as templates to demonstrate their sensitivity and applicability in pcr-based detection assays. with pure cultures, the sensitivities of detection by fta filter-based pcr were 30 to 50 and 200 cfu for the gram-negative enterics and listeria, respectively. different numbers of s. flexneri cells were used in controlled contamination experiments with ... | 2000 | 11010913 |
| isolation and antibiotic susceptibility of salmonella, shigella, and campylobacter from acute enteric infections in egypt. | while campylobacter, salmonella, and shigella remain major contributors to acute enteric infections, few studies on these pathogens have been conducted in egypt. from january 1986 to december 1993, 869 salmonella, shigella and campylobacter strains were isolated from stool specimens from 6,278 patients, presenting to the abbassia fever hospital, cairo, egypt, with acute enteric infections. salmonella predominated, totalling 465 isolates, followed by shigella with 258 isolates, and campylobacter ... | 2000 | 11014768 |
| vibrio fischeri lipopolysaccharide induces developmental apoptosis, but not complete morphogenesis, of the euprymna scolopes symbiotic light organ. | during initiation of the association between the squid host euprymna scolopes and its bacterial partner vibrio fischeri, the bacteria induce dramatic morphogenesis of the host symbiotic organ, a portion of which involves the signaling of widespread apoptosis of the cells in a superficial ciliated epithelium on the colonized organ. in this study, we investigated the role in this process of lipopolysaccharide (lps), a bacterial cell-surface molecule implicated in the induction of animal cell apopt ... | 2000 | 11023684 |
| ipgd, a protein secreted by the type iii secretion machinery of shigella flexneri, is chaperoned by ipge and implicated in entry focus formation. | invasion of epithelial cells by shigella flexneri involves entry and intercellular dissemination. entry of bacteria into non-phagocytic cells requires the ipaa-d proteins that are secreted by the mxi-spa type iii secretion machinery. type iii secretion systems are found in several gram-negative pathogens and serve to inject bacterial effector proteins directly into the cytoplasm of host cells. in this study, we have analysed the ipgd protein of s. flexneri, the gene of which is located on the vi ... | 2000 | 11029686 |
| bifidobacterium strains from resident infant human gastrointestinal microflora exert antimicrobial activity. | the gastrointestinal microflora exerts a barrier effect against enteropathogens. the aim of this study was to examine if bifidobacteria, a major species of the human colonic microflora, participates in the barrier effect by developing antimicrobial activity against enterovirulent bacteria. | 2000 | 11034580 |
| key role for dsba in cell-to-cell spread of shigella flexneri, permitting secretion of ipa proteins into interepithelial protrusions. | dsba, a disulfide bond catalyst, is necessary for realization of the pathogenic potential of shigella flexneri. sh42, a mutant strain differing from wild-type m90ts solely because it expresses nonfunctional dsba33g (substitution for 33c at the active site), secreted less ipab and ipac than m90ts in response to various stimuli in vitro. a kinetic study demonstrated that sh42 responded more slowly to congo red than m90ts. by modulating relative concentrations of functional and nonfunctional dsba w ... | 2000 | 11035758 |
| zentralblatt für bakteriologie--100 years ago: the isolation of shigella flexneri. | 2000 | 11043976 | |
| the ternary transformation system: constitutive virg on a compatible plasmid dramatically increases agrobacterium-mediated plant transformation. | this paper describes a so-called ternary transformation system for plant cells. we demonstrate that agrobacterium tumefaciens strain lba4404 supplemented with a constitutive virg mutant gene (virgn54d) on a compatible plasmid is capable of very efficient t-dna transfer to a diverse range of plant species. for the plant species catharanthus roseus it is shown that increased t-dna transfer results in increased stable transformation frequencies. analysis of stably transformed c. roseus cell lines s ... | 2000 | 11052201 |
| shigella flexneri bacteremia in a middle-aged immunocompetent woman. | 2000 | 11055675 | |
| uptake pathways of clinical and healthy animal isolates of campylobacter jejuni into int-407 cells. | campylobacter jejuni isolates obtained from human and animal sources showed different invasion levels into human embryonic intestinal (int-407) cells. there was no significant relation between the degree of invasion and cytotoxins production. the depolymerization of both microfilaments by cytochalasin-d and microtubules by colchicine, demecolcine and nocodazole or stabilization of microtubules by paclitaxel reduced the invasiveness of c. jejuni, although microfilament depolymerization showed gre ... | 2000 | 11064267 |
| isolation and characterization of a shigella flexneri invasin complex subunit vaccine. | the invasiveness and virulence of shigella spp. are largely due to the expression of plasmid-encoded virulence factors, among which are the invasion plasmid antigens (ipa proteins). after infection, the host immune response is directed primarily against lipopolysaccharide (lps) and the virulence proteins (ipab, ipac, and ipad). recent observations have indicated that the ipa proteins (ipab, ipac, and possibly ipad) form a multiprotein complex capable of inducing the phagocytic event which intern ... | 2000 | 11083774 |
| studies of the small bowel surface by scanning electron microscopy in infants with persistent diarrhea. | we describe the ultrastructural abnormalities of the small bowel surface in 16 infants with persistent diarrhea. the age range of the patients was 2 to 10 months, mean 4.8 months. all patients had diarrhea lasting 14 or more days. bacterial overgrowth of the colonic microflora in the jejunal secretion, at concentrations above 10(4) colonies/ml, was present in 11 (68.7%) patients. the stool culture was positive for an enteropathogenic agent in 8 (50.0%) patients: for epec o111 in 2, epec o119 in ... | 2000 | 11105095 |
| the virulence plasmid pwr100 and the repertoire of proteins secreted by the type iii secretion apparatus of shigella flexneri. | bacteria of shigella spp. are the causative agents of shigellosis. the virulence traits of these pathogens include their ability to enter into epithelial cells and induce apoptosis in macrophages. expression of these functions requires the mxi-spa type iii secretion apparatus and the secreted ipaa-d proteins, all of which are encoded by a virulence plasmid. in wild-type strains, the activity of the secretion apparatus is tightly regulated and induced upon contact of bacteria with epithelial cell ... | 2000 | 11115111 |
| further studies on the gs element. a novel mycobacterial insertion sequence (is1612), inserted into an acetylase gene (mpa) in mycobacterium avium subsp. silvaticum but not in mycobacterium avium subsp. paratuberculosis. | we have recently described the gs element, found in mycobacterium avium subsp. paratuberculosis (map), mycobacterium avium subsp. silvaticum (mas) and some isolates of mycobacterium avium subsp. avium serotype 2 (maas2), which contains a set of genes of low gc% content, putatively associated with the biosynthesis, modification and transference of fucose to cell wall glycopeptidolipids. here we describe a further gene of low gc% content (mpa), within the gs element in map. mpa is a putative acety ... | 2000 | 11118730 |
| [diagnostic value of a novel nutrient medium for isolation and cultivation of pathogens causing enteric yersiniosis and pseudotuberculosis]. | a new nutrient medium for isolation and cultivation of the causative agents of enteric yersiniosis and pseudotuberculosis was found to have advantages over endo medium in its differentiating and inhibiting properties. this medium permitted the easy differentiation of yersinia pseudotuberculosis from y. enterocolitica, as well as from escherichia coli, shigella flexneri, klebsiella pneumoniae, k. rhinoscleromatis, hafnia, enterobacter and citrobacter by color; from proteus inconstans by swarming. ... | 2000 | 11210625 |
| [bactericidal properties of hemo-cytolysin from vibrio cholerae non o1 p-11702 strain in a panel of indicator cultures for detection of vibriocins]. | the influence of the preparation of hemo-cytolysin, obtained from v. cholerae non o1 strain p-11702 and inducing lysis of both red blood cells and v. cholerae cultures using a panel of indicator cultures for the detection of vibriocins, was studied. the set of indicator cultures contained 2 shigella flexneri strains, 1 s. dysenteriae strain, 3 s. sonnei strains, 3 escherichia coli strains and 2 v. cholerae strains, one of them being atypical. hemo-cytolysin exhibited lytic activity with respect ... | 2000 | 11210647 |
| the pathogenesis of shigella flexneri infection: lessons from in vitro and in vivo studies. | shigella flexneri is a gram-negative facultatively intracellular pathogen responsible for bacillary dysentery in humans. more than one million deaths occur yearly due to infections with shigella spp. and the victims are mostly children of the developing world. the pathogenesis of shigella centres on the ability of this organism to invade the colonic epithelium where it induces severe mucosal inflammation. much information that we have gained concerning the pathogenesis of shigella has been deriv ... | 2000 | 10874731 |
| cd44 binds to the shigella ipab protein and participates in bacterial invasion of epithelial cells. | shigella entry into epithelial cells is characterized by a transient reorganization of the host cell cytoskeleton at the site of bacterial interaction with the cell membrane, which leads to bacterial engulfment in a macropinocytic process. using affinity chromatography on hela cell extracts, we show here that the hyaluronan receptor cd44 associates with ipab, a shigella protein that is secreted upon cell contact. overlay and solid-phase assays indicated that ipab binds directly to the extracellu ... | 2000 | 11207560 |
| pathogen-induced apoptosis of macrophages: a common end for different pathogenic strategies. | microbe-macrophage interactions play a central role in the pathogenesis of many infections. several bacterial pathogens induce apoptosis specifically in macrophages, but the mechanisms by which it occurs differ, and the resulting pathology can take different courses. macrophage death caused by shigella flexneri and salmonella spp. has been shown to result in the release of pro-inflammatory cytokines. conversely, yersinia spp. induce apoptosis by suppressing the signalling pathways that lead to t ... | 2000 | 11207583 |
| the regulatory protein phop controls susceptibility to the host inflammatory response in shigella flexneri. | the phop/phoq two-component regulatory system controls transcription of several key virulence genes essential for salmonella survival in the host cell phagosome. here, we determine that the phop/phoq system also regulates virulence in the aetiological agent of bacillary dysentery, shigella flexneri, even though this pathogen escapes from the phagosome into the cytoplasm of the host cell. a phop mutant of shigella established infections and induced an acute inflammatory response in two different ... | 2000 | 11207599 |
| functional role for the class ix myosin myr5 in epithelial cell infection by shigella flexneri. | efficient control of shigella-induced, rho-dependent cytoskeletal rearrangements seems to be required to shape the delicate cellular structures associated with bacterial invasion of epithelial cells. we therefore studied a class ix myosin and rho antagonist, the gtpase-activating protein (gap) myr5, for a potential role in the bacterial entry process. we show that myr5 is recruited into bacterial entry spots. the recruitment pattern resembled that of rhoc or ezrin, but not rhoa, rac or cdc42, wh ... | 2000 | 11207612 |