Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| complete dna sequence and analysis of the large virulence plasmid of shigella flexneri. | the complete sequence analysis of the 210-kb shigella flexneri 5a virulence plasmid was determined. shigella spp. cause dysentery and diarrhea by invasion and spread through the colonic mucosa. most of the known shigella virulence determinants are encoded on a large plasmid that is unique to virulent strains of shigella and enteroinvasive escherichia coli; these known genes account for approximately 30 to 35% of the virulence plasmid. in the complete sequence of the virulence plasmid, 286 open r ... | 2001 | 11292750 |
| high pressure increases bactericidal activity and spectrum of lactoferrin, lactoferricin and nisin. | we have studied the inactivation of a panel of eight test bacteria (two escherichia coli strains, salmonella enteritidis, salmonella typhimurium, shigella sonnei, shigella flexneri, pseudomonas fluorescens and staphylococcus aureus) by high pressure in the presence of bovine lactoferrin (500 microg/ml), pepsin hydrolysate of lactoferrin (500 microg/ml), lactoferricin (20 microg/ml) and nisin (100 iu/ml). none of these compounds, at the indicated dosage, were bactericidal when applied at atmosphe ... | 2001 | 11294354 |
| microbial growth modelling with artificial neural networks. | there is a growing interest in modelling microbial growth as an alternative to time-consuming, traditional, microbiological enumeration techniques. several statistical models have been reported to describe the growth of different microorganisms, but there are accuracy problems. an alternate technique 'artificial neural networks' (ann) for modelling microbial growth is explained and evaluated. published data were used to build separate general regression neural network (grnn) structures for model ... | 2001 | 11294356 |
| prospective cohort studies of shigellosis during military field training. | epidemiological and clinical features of shigellosis occurring among cohorts of israeli recruits followed-up for 3-6 months during the summer field training of years 1993-1997 were studied. the incidence rate of culture-proven shigellosis was the highest (78 cases per 1,000 recruits) in 1996 and the lowest (13 cases per 1,000 recruits) in 1995. shigella sonnei (152 isolates) and shigella flexneri (151 isolates) were the most common species. fifty percent of the patients with shigellosis had feve ... | 2001 | 11305466 |
| a synaptojanin-homologous region of salmonella typhimurium sigd is essential for inositol phosphatase activity and akt activation. | the ser-thr kinase akt is activated in epithelial cells by salmonella enterica serovar typhimurium. the bacterial effector sigd, which is translocated into host cells via the specialized type iii secretion system, is essential for akt activation. here, we investigated the inositol phospholipid substrate preferences of sigd. recombinant sigd preferentially dephosphorylated phosphatidylinositol 3,5-biphosphate and phosphatidylinositol 3,4,5-triphosphate over other phosphatidylinositol lipids. phos ... | 2001 | 11311241 |
| probiotic activities of lactobacillus casei rhamnosus: in vitro adherence to intestinal cells and antimicrobial properties. | the interest of probiotics as remedies for a broad number of gastrointestinal and other infectious diseases has gained wide interest over the last few years, but little is known about their underlying mechanism of action. in this study, the probiotic activities of a human isolate of lactobacillus casei subsp. rhamnosus strain (lcr35) were investigated. using intestinal caco-2 cell line in an in vitro model, we demonstrated that this strain exhibited adhesive properties. the inhibitory effects of ... | 2001 | 11316370 |
| shv-type extended-spectrum beta-lactamase in a shigella flexneri clinical isolate. | a shigella flexneri isolate resistant to oxyimino-cephalosporins was recovered from a stool sample of a 16 month-old algerian child hospitalized in paris, france. this isolate harboured an shv-2 beta-lactamase gene located on a c. 80 kb self-transferable plasmid. this is the first report of an ambler class a extended-spectrum beta-lactamase from shigella spp. | 2001 | 11328785 |
| [immunologic properties of coli surface antigen 6(cs6) of enterotoxigenic escherichia coli and cholera toxin subunit b expressed in shigella flexneri 2a strain t32]. | a host-plasmid balancing system composed with a delta asd mutant (fad) of an avirulent strain (t32) of shigella flexneri 2a and plasmid harboring asd gene was used to express enterotoxigenic e. coli surface antigen 6(cs6) and v. cholerae toxin subunit b (ctb). the results of western blotting and elisa showed that all of recombinant plasmids (pyx201, pyx202 and pyx203) could be maintained stably and expressed cs6 and ctb respectively in t32 without any antibiotic selection. all the recombinant ba ... | 2001 | 11330183 |
| chvd, a chromosomally encoded atp-binding cassette transporter-homologous protein involved in regulation of virulence gene expression in agrobacterium tumefaciens. | a yeast two-hybrid screen searching for chromosomally encoded proteins that interact with the agrobacterium tumefaciens virb8 protein was carried out. this screen identified an interaction candidate homologous to the partial sequence of a gene that had previously been identified in a transposon screen as a potential regulator of virg expression, chvd. in this report, the cloning of the entire chvd gene is described and the gene is sequenced and characterized. insertion of a promoterless lacz gen ... | 2001 | 11344138 |
| identification and functional characterization of arylamine n-acetyltransferases in eubacteria: evidence for highly selective acetylation of 5-aminosalicylic acid. | arylamine n-acetyltransferase activity has been described in various bacterial species. bacterial n-acetyltransferases, including those from bacteria of the gut flora, may be involved in the metabolism of xenobiotics, thereby exerting physiopathological effects. we characterized these enzymes further by steady-state kinetics, time-dependent inhibition, and dna hybridization in 40 species, mostly from the human intestinal microflora. we report for the first time n-acetyltransferase activity in 11 ... | 2001 | 11344150 |
| espg, a novel type iii system-secreted protein from enteropathogenic escherichia coli with similarities to vira of shigella flexneri. | the function of the rorf2 gene located on the locus of enterocyte effacement (lee) pathogenicity island of enteropathogenic escherichia coli (epec) has not been described. we report that rorf2 encodes a novel protein, named espg, which is secreted by the type iii secretory system and which is translocated into host epithelial cells. espg is homologous with shigella flexneri protein vira, and the cloned espg (rorf2) gene can rescue invasion in a shigella vira mutant, indicating that these protein ... | 2001 | 11349072 |
| cloning and characterization of aspergillus nidulans vpsa gene which is involved in vacuolar biogenesis. | in saccharomyces cerevisiae, vacuoles play very important roles in ph and osmotic regulation, protein degradation and storage of amino acids, small ions as well as polyphosphates. in filamentous fungi, however, little is known about vacuolar functions at a molecular level. in this paper, we report the isolation of the vpsa gene from the filamentous fungus aspergillus nidulans as a homologue of the vps1 gene of s. cerevisiae which encodes a dynamin-related protein. the vpsa gene encodes a polypep ... | 2001 | 11368897 |
| reconstitution of acetosyringone-mediated agrobacterium tumefaciens virulence gene expression in the heterologous host escherichia coli. | the ability to utilize escherichia coli as a heterologous system in which to study the regulation of agrobacterium tumefaciens virulence genes and the mechanism of transfer dna (t-dna) transfer would provide an important tool to our understanding and manipulation of these processes. we have previously reported that the rpoa gene encoding the alpha subunit of rna polymerase is required for the expression of lacz gene under the control of virb promoter (virbp::lacz) in e. coli containing a constit ... | 2001 | 11371534 |
| etiology of children's diarrhea in montevideo, uruguay: associated pathogens and unusual isolates. | we studied microorganisms associated with infant diarrhea in a group of 256 children admitted to a public pediatric hospital in montevideo, uruguay. diagnostic procedures were updated to optimize detection of potential pathogens, which were found in 63.8% of cases, and to be able to define their characteristics down to molecular or antigenic type. coinfection with two or more agents was detected in more than one-third of positive studies. escherichia coli enteric virotypes, especially enteropath ... | 2001 | 11376047 |
| mechanism of actin-based motility. | spatially controlled polymerization of actin is at the origin of cell motility and is responsible for the formation of cellular protrusions like lamellipodia. the pathogens listeria monocytogenes and shigella flexneri, which undergo actin-based propulsion, are acknowledged models of the leading edge of lamellipodia. actin-based motility of the bacteria or of functionalized microspheres can be reconstituted in vitro from only five pure proteins. movement results from the regulated site-directed t ... | 2001 | 11379633 |
| pathologic and physiologic interactions of bacteria with the gastrointestinal epithelium. | communication between microorganisms and the gastrointestinal epithelium, ie, bacterial-epithelial "crosstalk," is examined. because most basic research on the molecular interaction of bacteria with the gut epithelium relates to pathogen-enterocyte interaction, crosstalk with pathologic bacterial is considered in detail. through their interactions with the intestinal epithelium, pathogens can modify epithelium function to enhance their penetration across the epithelial barrier and to exploit muc ... | 2001 | 11393190 |
| prevalence of viral, bacterial and parasitic enteropathogens among young children with acute diarrhoea in jeddah, saudi arabia. | the prevalence of viral, bacterial and parasitic pathogens among children of jeddah, saudi arabia, was investigated. during december 1995-october 1996, 576 faecal samples were collected from children (0-5 year(s) old) suffering from acute diarrhoea and attending hospitals and outpatient clinics in jeddah. one or more enteropathogen(s) were identified in 45.6% of the stool specimens. mixed infections were detected in 12.2% of the diarrhoeal cases. rotavirus was detected in 34.6% of the specimens ... | 2001 | 11394180 |
| the iron- and temperature-regulated cjrbc genes of shigella and enteroinvasive escherichia coli strains code for colicin js uptake. | a cosmid library of dna from colicin js-sensitive enteroinvasive escherichia coli (eiec) strain o164 was made in colicin js-resistant strain e. coli vcs257, and colicin js-sensitive clones were identified. sensitivity to colicin js was associated with the carriage of a three-gene operon upstream of and partially overlapping senb. the open reading frames were designated cjrabc (for colicin js receptor), coding for proteins of 291, 258, and 753 amino acids, respectively. tn7 insertions in any of t ... | 2001 | 11395459 |
| efficient vir gene induction in agrobacterium tumefaciens requires vira, virg, and vir box from the same ti plasmid. | the vir genes of octopine, nopaline, and l,l-succinamopine ti plasmids exhibit structural and functional similarities. however, we observed differences in the interactions between octopine and nopaline vir components. the induction of an octopine vire(a6)::lacz fusion (psm358cd) was 2.3-fold higher in an octopine strain (a348) than in a nopaline strain (c58). supplementation of the octopine virg(a6) in a nopaline strain with psm358 did not completely restore vire(a6) induction. however, addition ... | 2001 | 11395473 |
| safety and immunogenicity of a proteosome-shigella flexneri 2a lipopolysaccharide vaccine administered intranasally to healthy adults. | we studied the safety and immunogenicity of a shigella flexneri 2a vaccine comprising native s. flexneri 2a lipopolysaccharide (lps) complexed to meningococcal outer membrane proteins-proteosomes-in normal, healthy adults. a two-dose series of immunizations was given by intranasal spray, and doses of 0.1, 0.4, 1.0, and 1.5 mg (based on protein) were studied in a dose-escalating design. the vaccine was generally well tolerated. the most common reactions included rhinorrhea and nasal stuffiness, w ... | 2001 | 11401998 |
| bacteria-mediated transfer of eukaryotic expression plasmids into mammalian host cells. | invasive intracellular bacteria are able to transfer eukaryotic expression plasmids into mammalian host cells in vitro and in vivo. this can be used to induce immune responses toward protein antigens encoded by the plasmid or to complement genetic defects. plasmid transfer takes place when the recombinant bacterium dies within the host cell, either due to metabolic attenuation or induction of autolysis. alternatively, antibiotics can be used and spontaneous transfer has also been observed, indic ... | 2001 | 11405218 |
| 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 |
| polymerase chain reaction detection of invasive shigella and salmonella enterica in food. | 2002 | 11692869 | |
| controlled expression in klebsiella pneumoniae and shigella flexneri using a bacteriophage p1-derived c1-regulated promoter system. | the utility of promoters regulated by the bacteriophage p1 temperature-sensitive c1 repressor was examined in shigella flexneri and klebsiella pneumoniae. promoters carrying c1 operator sites driving lacz expression had induction/repression ratios of up to 240-fold in s. flexneri and up to 50-fold in k. pneumoniae. the promoters exhibited remarkably low basal expression, demonstrated modulation by temperature, and showed rapid induction. this system will provide a new opportunity for controlled ... | 2001 | 11698385 |
| validation of salmonellosis and shigellosis diagnostic test kits at a provincial hospital in thailand. | rapid diagnosis of salmonellosis and shigellosis was performed using six different diagnostic test kits which recently have been made available commercially. they were salmo-dot, typhi-dot, shigel dot a, b, c, and d test kits for detection of salmonella spp., group d salmonellae, and groups a, b, c, and d shigella spp., respectively. the principle of all test kits is a membrane (dot) elisa using specific monoclonal antibodies to the respective pathogens as the detection reagents. the present stu ... | 2001 | 11699718 |
| shigella sonnei outbreak among men who have sex with men--san francisco, california, 2000-2001. | shigella sonnei causes approximately 10,000 cases of gastroenteritis each year in the united states. these infections occur predominately among young children and usually are associated with poor hygienic conditions in child-care settings. outbreaks of shigellosis among men who have sex with men (msm) have occurred because of direct or indirect oral-anal contact but usually are caused by shigella flexneri. this report describes an investigation of s. sonnei cases that occurred among msm in san f ... | 2001 | 11699845 |
| 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 |
| mxim and mxij, base elements of the mxi-spa type iii secretion system of shigella, interact with and stabilize the mxid secretin in the cell envelope. | the type iii secretion pathway is broadly distributed across many parasitic bacterial genera and serves as a mechanism for delivering effector proteins to eukaryotic cell surface and cytosolic targets. while the effectors, as well as the host responses elicited, differ among type iii systems, they all utilize a conserved set of 9 to 11 proteins that together form a bacterial envelope-associated secretory organelle or needle complex. the general structure of the needle complex consists of a trans ... | 2001 | 11717255 |
| lifestyles of the intracellular. | 2001 | 11728864 | |
| characterization of the interaction partners of secreted proteins and chaperones of shigella flexneri. | the type iii secretion (tts) system of gram-negative pathogenic bacteria is composed of proteins that assemble into the tts machinery, proteins that are secreted by this machinery and specific chaperones that are required for storage and sometimes secretion of these proteins. many sequential protein interactions are involved in the tts pathway to deliver effector proteins to host cells. we used the yeast two-hybrid system to investigate the interaction partners of the shigella flexneri effectors ... | 2001 | 11737652 |
| antimicrobial and anti-lipase activity of quercetin and its c2-c16 3-o-acyl-esters. | neither quercetin (q), nor 3-o-acylquercetines, up to 100 microg/ml, had any significant activity on selected gram-positive strains (staphylococcus aureus, bacillus subtilis, listeria ivanovi, listeria monocytogenes, listeria serligeri), gram-negative strains (escherichia coli, shigella flexneri, shigella sonnei, salmonella enteritidis, salmonella tiphymurium) and yeasts (candida albicans and candida glabrata). in addition, we confirmed the known anti-hiv activity of q (80% inhibition at 40 micr ... | 2002 | 11741775 |
| in vivo dna-binding and oligomerization properties of the shigella flexneri arac-like transcriptional regulator virf as identified by random and site-specific mutagenesis. | in shigella flexneri expression of the plasmid-encoded virulence genes is regulated via a complex mechanism involving both environmental signals and specific transactivators. the primary regulator protein, virf, is a member of the arac family of transcription factors and shares with other arac-like proteins a conserved carboxy-terminal domain thought to be important for dna binding. random and site-directed mutagenesis of the virf gene encoding virf yielded a number of mutations along the length ... | 2002 | 11751832 |
| blockade of cd14 aggravates experimental shigellosis. | shigella infections lead to severe inflammation associated with destruction of colonic mucosa. we assessed the effect of in vivo blockade of cd14 on the outcome of experimental shigella infection in rabbits. a total of 17 rabbits were divided into two groups: 8 received a single i.v. dose of anti-rabbit cd14 monoclonal antibody prior to infection with an invasive shigella flexneri strain; the remainder served as controls. the anti-cd14-treated rabbits exhibited more severe tissue destruction and ... | 2001 | 11753214 |
| epidemiology of shigellosis in lagos, nigeria: trends in antimicrobial resistance. | antimicrobial susceptibility of shigella spp. and escherichia coli, isolated from diarrhoeal patients in lagos, was studied from march 1999 to february 2000. four hundred fifty-nine isolates were identified as shigellae (62) and e. coli (397). shigella flexneri, s. dysenteriae, s. boydii, and s. sonnei accounted, respectively, for 51.6%, 17.7%, 17.7%, and 13% of the total number of shigellae isolated. eleven cases of shigellosis occurred in the age group of 0-9 years, 22 cases in the age group o ... | 2001 | 11761772 |
| evaluation of culture media for enrichment and isolation of shigella sonnei and s. flexneri. | the performance of gram-negative (gn) broth with (10 microg/ml) and without novobiocin, shigella broth (sb) with 0.5 and 3.0 microg/ml novobiocin, all incubated at 37 degrees c (sb with 3.0 microg/ml novobiocin also at 42 degrees c) and buffered brilliant green bile glucose (ee) broth with 1.0 microg/ml novobiocin incubated at 37 and 42 degrees c were evaluated for resuscitation and growth of shigella sonnei and s. flexneri (eight strains; unstressed, chill-stressed and acid-stressed) and non-sh ... | 2001 | 11764191 |
| [value of antibiotype and bacteriocinotype for differentiating shigella strains isolated in argentina]. | the aim of the present work was to analyse the phenotypical characteristics of shigella strains in order to evaluate their possible utilisation as epidemiological markers. for one year, we studied 95 strains of shigella obtained from stool specimens of patients with dysentery. bacteria came from various health care centres in the states of chaco and corrientes (argentina). bacteria were identified by using classical biochemical methods. all strains were serotyped and susceptibility patterns were ... | 2000 | 11775312 |
| differential expression of inducible nitric oxide synthase is associated with differential toll-like receptor-4 expression in chicken macrophages from different genetic backgrounds. | the purpose of this study was to examine inos gene expression and activity in macrophages from different chicken genetic lines against various bacterial lps. furthermore, the possible involvement of surface lps receptors as candidates for differential inos gene induction in these genetic lines of chicken was also examined. sephadex-elicited abdominal macrophages (1 x 10(6)) as well as inos hyper-responder macrophages from a transformed chicken macrophage cell line, mq-ncsu, were exposed to 5 mic ... | 2002 | 11777534 |
| 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 |
| pathogenic effects of opolysaccharide from shigella flexneri strain. | aim:to investigate the specific pathogenesis of o-polysaccharide (o-ps) which is on the outer membrane of lipopolysaccharides (lps) from shigella flexneri.methods:the o-ps was isolated and purified from shigella flexneri 5 m90t by enzymatic hydrolysis and gel chromatography. effects of o-ps were observed by in vitro experiment, (hela cell culture), and in vivo experiment (rabbit ileal loop assay).results:in vitro and in vivo experiments with the purified o-ps from shigella flexneri revealed that ... | 1999 | 11819440 |
| 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 |
| chronic vulvovaginitis caused by antibiotic-resistant shigella flexneri in a prepubertal child. | a 7-year 8-month-old girl was diagnosed with a prolonged course of vulvovaginitis caused by shigella flexneri. the child was symptomatic with intermittent vaginal bleeding, dysuria and foul smelling vaginal discharge for a 3-year period. initial attempts to resolve the infection with successive courses of antibiotic therapy using ampicillin, trimethoprim-sulfamethoxazole, cefixime and amoxicillin/clavulanic acid failed. the child's infection was finally resolved by a 14-day course of ciprofloxac ... | 2002 | 11840089 |
| shigella spa32 is an essential secretory protein for functional type iii secretion machinery and uniformity of its needle length. | the shigella type iii secretion machinery is responsible for delivering to host cells the set of effectors required for invasion. the type iii secretion complex comprises a needle composed of mxih and mxii and a basal body made up of mxid, mxig, and mxij. in s. flexneri, the needle length has a narrow range, with a mean of approximately 45 nm, suggesting that it is strictly regulated. here we show that spa32, encoded by one of the spa genes, is an essential protein translocated via the type iii ... | 2002 | 11844752 |
| 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 |
| molecular dissection of virb, a key regulator of the virulence cascade of shigella flexneri. | the virb protein is a key regulator of virulence gene expression in the facultative enteroinvasive pathogen shigella flexneri. while genetic evidence has shown that it is required for activation of transcription of virulence genes located on a 230-kb plasmid in this bacterium, hitherto, evidence that virb is a dna-binding protein has been lacking. although virb shows extensive homology to proteins involved in plasmid partitioning, it does not resemble any known conventional transcription factor. ... | 2002 | 11850420 |
| shigella flexneri interactions with the basolateral membrane domain of polarized model intestinal epithelium: role of lipopolysaccharide in cell invasion and in activation of the mitogen-activated protein kinase erk. | an early step governing shigella flexneri pathogenesis is the invasion of the colonic epithelium from the basolateral surface followed by disruption of the colonic epithelial barrier. despite recent insight into s. flexneri-host interactions, much remains to be determined regarding the nature of the initial contact between s. flexneri and the host epithelial basolateral membrane domain. since the lipopolysaccharide (lps) is located at the outermost part of the bacterial membrane, we considered t ... | 2002 | 11854195 |
| [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 |
| [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 |
| cdc42 facilitates invasion but not the actin-based motility of shigella. | the enteric pathogen shigella utilizes host-encoded proteins to invade the gastrointestinal tract. efficient invasion of host cells requires the stimulation of rho-family gtpases and cytoskeletal alterations by shigella-encoded ipac. following invasion and lysis of the phagosome, shigella exploits the host's actin-based polymerization machinery to assemble an actin tail that serves as the propulsive force required for spreading within and between cells. the shigella surface protein icsa stimulat ... | 2002 | 11864577 |
| complete genomic sequence of sfv, a serotype-converting temperate bacteriophage of shigella flexneri. | bacteriophage sfv is a temperate serotype-converting phage of shigella flexneri. sfv encodes the factors involved in type v o-antigen modification, and the serotype conversion and integration-excision modules of the phage have been isolated and characterized. we now report on the complete sequence of the sfv genome (37,074 bp). a total of 53 open reading frames were predicted from the nucleotide sequence, and analysis of the corresponding proteins was used to construct a functional map. the gene ... | 2002 | 11889106 |
| genetic determinants of tetracycline resistance in vibrio harveyi. | isolates of vibrio harveyi, a prawn pathogen, have demonstrated multiple antibiotic resistance to commonly used antimicrobial agents, such as oxytetracycline. in this paper, we describe the cloning and characterization of two tetracycline resistance determinants from v. harveyi strain m3.4l. the first resistance determinant, cloned as a 4,590-bp fragment, was identical to teta and flanking sequences encoded on transposon tn10 from shigella flexneri. the second determinant, cloned as a 3,358-bp f ... | 2002 | 11897587 |
| the escherichia coli k-12 shea gene encodes a 34-kda secreted haemolysin. | haemolytic toxins belong to one of several classes of virulence factors that contribute to bacterial pathogenicity. the non-pathogenic escherichia coli k-12 laboratory strain was considered for years to be non-haemolytic. however, overproduction of several transcriptional regulators induced the appearance of a haemolytic activity that is absent under usual laboratory growth conditions. in this work, we have cloned and characterized an e. coli k-12 gene, shea, whose overexpression results in a ha ... | 1997 | 11902713 |
| wild-type intracellular bacteria deliver dna into mammalian cells. | gene transfer in vitro from intracellular bacteria to mammalian phagocytic and non-phagocytic cells and in vivo in mice has been reported. the bacteria used as dna delivery vectors were engineered to lyze upon entry in the cell due to impaired cell wall synthesis for shigella flexneri and invasive escherichia coli, or production of a phage lysin for listeria mono- cytogenes. in vivo gene transfer was obtained with attenuated salmonella typhimurium and resulted in stimulation of mucosal immunity. ... | 2002 | 11906454 |
| prevalence of the sat gene among clinical isolates of shigella spp. causing travelers' diarrhea: geographical and specific differences. | 2002 | 11923399 | |
| development of a p1 phagemid system for the delivery of dna into gram-negative bacteria. | the inability to transform many clinically important gram-negative bacteria has hampered genetic studies addressing the mechanism of bacterial pathogenesis. this report describes the development and construction of a delivery system utilizing the broad-host-range transducing bacteriophage p1. the phagemids used in this system contain a p1 pac initiation site to package the vector, a p1 lytic replicon to generate concatemeric dna, a broad-host-range origin of replication and an antibiotic-resista ... | 2002 | 11932441 |
| 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 |
| studies on o-specific polysaccharides of shigella flexneri 1b(i) and its smooth mutant z(iii). | 1970 | 11947597 | |
| [phenomenon of apoptosis in the survival of enterobacteria in the parasite-host system]. | data on the apoptosis phenomenon with enterobacteria used as a model are presented. one of the mechanisms regulating the vital activity of eukaryotic cells is, together with cell proliferation and differentiation, the phenomenon known as "apoptosis". this physiological process of the eukaryotic cells death is used by many parasites in parasite--host relationships in different epitopes. the system known to trigger programmed cell death, is the surface receptor fas, the receptor of tumor necrosis ... | 2002 | 11949266 |