| [fulminant encephalopathy due to shigella flexneri]. | in some rare cases, shigella flexneri infection may be associated with fulminating encephatopathy. | 1996 | 8952794 |
| serological characterisation of anti-endotoxin sera directed against the conjugates of oligosaccharide core of escherichia coli type r1, r2, r3, j5 and salmonella ra with tetanus toxoid. | the covalent conjugates of oligosaccharide core: escherichia coli type r1, r2, r3, j5 and salmonella ra with tetanus toxoid have been prepared using reaction of reductive amination. the neoglycoconjugates were good immunogens in rabbits yielding a high level of anti-lipopolysaccharide antibodies of igg class. the antibodies were used to examine the possibility of their reactions with smooth lipopolysaccharides. we have found that all antisera were able to react with the lipopolysaccharide molecu ... | 1996 | 8954349 |
| cloning, expression, and affinity purification of recombinant shigella flexneri invasion plasmid antigens ipab and ipac. | shigella flexneri and related enteropathogenic bacteria are important agents of bacillary dysentery, a potentially life-threatening illness for children in underdeveloped regions of the world. onset of shigellosis stems from s. flexneri invasion of colonic epithelial cells, leading to localized cell death and inflammation. invasion plasmid antigens (ipa) b, c, and d are three secreted proteins encoded by the large virulence plasmid of s. flexneri that have been implicated as essential effectors ... | 1996 | 8954886 |
| apoptosis as a trigger of inflammation in shigella-induced cell death. | | 1996 | 8968510 |
| a pathogen-specific epitope inserted into recombinant secretory immunoglobulin a is immunogenic by the oral route. | oral administration of rabbit secretory iga (siga) to adult balb/c mice induced iga+, igm+, and igg+ lymphoblasts in the peyer's patches, whose fusion with myeloma cells resulted in hybridomas producing iga, igm, and igg1 antibodies to the secretory component (sc). this suggests that sc could serve as a vector to target protective epitopes into mucosal lymphoid tissue and elicit an immune response. we tested this concept by inserting a shigella flexneri invasin b epitope into sc, which, followin ... | 1996 | 8969237 |
| shigella flexneri is trapped in polymorphonuclear leukocyte vacuoles and efficiently killed. | we examined the bactericidal activity of polymorphonuclear leukocytes (pmn) against an invasive wild-type strain of shigella flexneri (m90t) and a plasmid-cured noninvasive derivative (bs176). both shigella strains, as well as a rough strain of escherichia coli, were killed with similar efficiencies by intact inflammatory pmn in room air and under n2 (i.e., killing was o2 independent). bacterial killing by pmn extracts was substantially inhibited by antibodies to the bactericidal/permeability-in ... | 1997 | 8975899 |
| examination of coumarins, flavonoids and polysaccharopeptide for antibacterial activity. | 1. coumarins, flavonoids and polysaccharopeptide were tested for antibacterial activity. 2. the bacteria used for this study included clinical isolates of staphylococcus aureus, shigella flexneri, salmonella typhi, escherichia coli and pseudomonas aeruginosa. 3. most of the coumarins tested failed to inhibit the bacteria at 25 mg/l. edultin at 128 mg/l inhibited 4 of the 8 p. aeruginosa strains and 1 of the s. aureus strains tested. o-acetylcolumbianetin and imperatorin did not inhibit any isola ... | 1996 | 8981074 |
| variation in salmonella core lipopolysaccharide as detected by the monoclonal antibody m105. | the lipopolysaccharide antigenicity of 22 salmonella strains (representing nine serogroups) and four non-salmonellae enterobacteriaceae to the salmonella genus specific monoclonal antibody m105 was analysed. the monoclonal antibody m105 reacted with all 22 salmonella strains. probing sds-page separated lps molecules with mab m105 revealed that the antibody reacted with the core region of all salmonella serovars. however, no reaction was obtained to the long-chain lps of serovars o (salm. adelaid ... | 1996 | 8987449 |
| construction of a stable and non-resistant bivalent vaccine candidate strain against shigella flexneri 2a and shigella sonnei. | the e. coli cs3 gene coding for cfa/ii antigen was site-specifically integrated into the asd gene locus of s. flexneri 2a vaccine strain t32, resulting in the inactivation of the asd gene. meanwhile, the gene cluster for s. sonnei o antigen was cloned into a non-resistant expression vector pxl378 to construct the plasmid pxl390. by transforming the asd-mutant of the t32 strain with pxl390, the bivalent vaccine candidate strain fs01 against s. flexneri 2a and s. sonnei was finally obtained. exper ... | 1996 | 8988355 |
| antibody response of monkeys to invasion plasmid antigen d after infection with shigella spp. | the antigen preparation most often used for determining the levels of antibodies to virulence-associated proteins of shigella spp. consists of a mixture of proteins (including ipab, ipac, ipad, and virg*) extracted from virulent shigellae with water (water extract). to overcome the lack of specificity for individual antigens in the water-extract enzyme-linked immunosorbent assay (elisa), the ipad gene from s. flexneri has been cloned, expressed to a high level, and purified for use in a new elis ... | 1996 | 8991646 |
| serological identification of shigella flexneri strains by the coagglutination reaction. | several variants of reagents were prepared by coupling type (i, ii iii, iv, v and vi) and group (3, 4, 6 and 7, 8, 9) anti-shigella flexneri sera with protein a--containing staphylococcal suspension. for most serum lots coagglutination led to a 1/10 minimum dilution. however, different efficiencies were reported between serum lots and even within the same type or group. no improvement by the coagglutination reaction could be obtained for one lot from group 3, 4 and 7, 8, 9 sera and for both type ... | 1995 | 8993123 |
| purification of ipac, a protein involved in entry of shigella flexneri into epithelial cells and characterization of its interaction with lipid membranes. | entry of shigella flexneri into epithelial cells and lysis of the phagosome involve the secreted ipaa-d proteins. a complex containing ipac and ipab is able to promote uptake of inert particles by epithelial cells. this suggested that ipa proteins, either individually or as a complex, might interact with the cell membrane. we have purified ipac and demonstrated its interaction with lipid vesicles. this interaction is modulated by the ph, which might be relevant to the dual role of ipa proteins, ... | 1997 | 9001387 |
| [high percentage of antibiotic resistance in shigella infections in children in curaçao]. | to evaluate antimicrobial treatment and resistance in clinical childhood shigellosis. | 1996 | 9005333 |
| [treatment of flexner's dysentery with ofloxacin]. | twenty four patients with dysentery due to shigella flexneri2a and 1 patient with mixed infection (acute dysentery due to sh.flexneri 2a+group b salmonellosis) were treated with ofloxacin. the patients were divided into 4 groups. in group i ofloxacin was administered intravenously in a dose of 200 mg twice a day followed by its oral use in the form of tablets in a dose of 200 mg twice a day for 5 to 6 days. in group ii ofloxacin was used orally in the form of tablets in a dose of 200 mg once a d ... | 1996 | 9005798 |
| characterization of the stable maintenance of the shigella flexneri plasmid phs-2. | phs-2 is a 3-kb plasmid originally isolated from shigella flexneri infections associated with reactive arthritis in humans. this plasmid is stably maintained in many clinical isolates of shigella flexneri. the nucleotide sequence of this plasmid displays two closely linked regions that may play a role in the maintenance of this plasmid. one region consists of a 250-bp locus showing a significant homology to the cole1 cer site. the results indicate that the cer-like site of phs-2, like the cole1 ... | 1996 | 9007013 |
| induction of tumor necrosis factor and nitric oxide by shigella strains isolated from patients with or without neurologic manifestations. | the pathogenesis of the shigella-associated neurological symptoms is unclear. we examined the potential role of host factors. sonicates of shigella strains isolated from children with and without neurologic disturbances were compared regarding their ability to induce tumor necrosis factor (tnf) and nitric oxide (no) in vitro, in mouse macrophage j744 cell line. the mean concentrations of tnf (14.6 vs. 4.4 ng/ml) and no (7.4 vs. 3.7 microm) induced were higher in response to strains isolated from ... | 1996 | 9007170 |
| presence of stra-strb gene within a streptomycin-resistance operon in a clinical isolate of shigella flexneri. | three aminoglycoside-modifying enzymes (ames) were produced by a clinical isolate of shigella flexneri which was resistant to gentamicin, tobramycin, netilmicin, kanamycin, sisomicin and streptomycin: acetyltransferase (aac) (3)-ii-type, and phosphotransferase (aph) (3")- and (6)-type enzymes. the aminoglycoside-resistance genes were located on a 75-kb plasmid. two genes, stra-hk and strb-hk, in a transcriptional unit were found to code for streptomycin-resistance. the genetic organization and s ... | 1996 | 9007957 |
| screening of in vitro antibacterial activity from syzygium guineense (willd) hydrosoluble dry extract. | diarrhoea is one of the most important causes of infant mortality in the world. as modern drugs are expensive or unavailable in developing countries, many people use traditional medicines in africa for the treatment of several diseases. in our study, we investigated the antibacterial activity of syzygium guineense extract in order to assess its activity on some bacterial strains involved in diarrhoeal diseases and to justify its use. the aqueous dry extract was prepared by decoction followed by ... | 1996 | 9008903 |
| in situ characterization of inflammatory responses in the rectal mucosae of patients with shigellosis. | shigella species cause bacillary dysentery in humans by invading epithelial cells of the colonic mucosa leading to colonic epithelial cell destruction and inflammation. for further analysis of local gut inflammation, morphological changes and the potential involvement of mediators in regulatory mechanisms of cell activation and cell proliferation were studied immunohistochemically in rectal mucosal biopsies taken from patients during the acute phase of shigellosis and at convalescence. rectal bi ... | 1997 | 9009337 |
| secretion of shigella flexneri ipa invasins on contact with epithelial cells and subsequent entry of the bacterium into cells are growth stage dependent. | upon contact with the surface of epithelial cells, shigella flexneri secretes ipa proteins through the mxi-spa type iii secretion apparatus. among the ipa proteins, ipab and ipac form a soluble complex in the bacterial supernatant which appears to be sufficient to initiate the cellular rearrangements necessary to achieve bacterial entry. here, we provide the first evidence that efficiency of bacterial entry into cells depends on the stage of bacterial growth. bacteria in the early phase of expon ... | 1997 | 9009341 |
| ipab, a shigella flexneri invasin, colocalizes with interleukin-1 beta-converting enzyme in the cytoplasm of macrophages. | shigellae are the most prevalent etiological agents of dysentery. a crucial step in shigella pathogenesis is the induction of macrophage apoptosis. the invasion plasmid antigen b (ipab) is necessary and sufficient to induce macrophage programmed cell death. ipab activates apoptosis by binding to interleukin-1 beta (il-1 beta)-converting enzyme (ice) or a highly homologous protease. here, we show that ipab is disseminated throughout the cytoplasm of shigella-infected macrophages as detected by bo ... | 1997 | 9009343 |
| expression of aerobactin genes by shigella flexneri during extracellular and intracellular growth. | the expression of the shigella flexneri chromosomal aerobactin genes during growth of the bacterium within tissue culture cells was assayed. during intracellular growth, aerobactin promoter activity was repressed relative to the level observed in bacteria grown extracellularly, even when the bacteria had been starved for iron prior to infection. similarly, the level of one of the proteins encoded by this operon, the aerobactin outer membrane receptor, iut, was reduced in the intracellular enviro ... | 1997 | 9009350 |
| actin and cell pathogenesis. | the bacterial pathogens listeria monocytogenes and shigella flexneri recruit host factors that enable them to use actin polymerization as the driving force to facilitate their spread into neighbouring cells. it is now becoming clear that other pathogens, including viruses, have developed a number of different strategies to use the actin cytoskeleton of the host to their advantage during the infection process. | 1997 | 9013675 |
| rho, a small gtp-binding protein, is essential for shigella invasion of epithelial cells. | shigella, the causative agents of bacillary dysentery, are capable of invading mammalian cells that are not normally phagocytic. uptake of bacteria by the mammalian cells is directed by bacterial factors named ipab, ipac, and ipad invasins, in which ipa invasins secreted into the bacterial environment can interact with alpha5beta1 integrin. we report here that shigella invasion of epithelial cells requires rho activity, a ras-related gtp-binding protein. the invasive capacity of shigella flexner ... | 1997 | 9016877 |
| changing patterns of the prevalence of different shigella species and their antibiotic susceptibilities in ankara, turkey. | shigella flexneri was the most common shigella serogroup isolated in turkey. recently, an increase in the number of shigella sonnei isolates was noticed. a retrospective analysis of 2,710 isolates, obtained from stools of turkish children between january 1980 and september 1994, revealed that, between 1980 and 1987, s. flexneri was the most common subgroup. the isolation rate of s. sonneri increased steadily from 1987 to 1994 reaching to a peak of 78% of all isolates in 1991. the antibiotic susc ... | 1996 | 9019012 |
| transferable hyperproduction of tem-1 beta-lactamase in shigella flexneri due to a point mutation in the pribnow box. | tem-1 hyperproduction in two ampicillin-sulbactam-resistant shigella flexneri strains was studied. in both strains the blatem gene was encoded as a single copy on a large conjugatively transferable plasmid. a single g-->t transversion at position 1 of the -10 consensus sequence was identified to be the mechanism of tem-1 hyperproduction. | 1997 | 9021210 |
| identification and characterization of the dtdp-rhamnose biosynthesis and transfer genes of the lipopolysaccharide-related rfb locus in leptospira interrogans serovar copenhageni. | immunity to leptospirosis is principally humorally mediated and involves opsonization of leptospires for phagocytosis by macrophages and neutrophils. the only protective antigen identified to date is the leptospiral lipopolysaccharide (lps), which biochemically resembles typical gram-negative lps but has greatly reduced endotoxic activity. little is known about the structure of leptospiral lps. a 2.1-kb ecori fragment from the chromosome of serovar copenhageni was cloned in puc18 in escherichia ... | 1997 | 9023210 |
| [the pathogenetic and clinico-diagnostic significance of changes in leukocyte migration activity in patients with shigellosis and salmonellosis]. | the peripheral blood leukocyte migration activity (lma) was studied in 134 acute dysentery patients and 129 salmonellosis patients by using the in vitro screening assay of cell migration (sacm) from microcultures, stimulated with lps antigens from a number of enteric pathogens. at the acute period of the disease (days 1-5) in the greater part of the patients (80-90%) the specific acceleration of lma, later followed by its inhibition, was registered in the presence of the pronounced intoxication ... | 1996 | 9027172 |
| [the epidemiological characteristics of sonne and flexner dysentery in st. petersburg in 1953-1994]. | in connection with the growth of mortality in flexner's dysentery observed since 1991 and a rise in morbidity in this infection since 1993 the data on the registered cases of shigella flexneri and shigella sonnei infections in st. petersburg for the period of 1953-1994 were analyzed. in the 60-80s the specific features of the epidemic process was determined by s. sonnei infection which constituted up to 90% of all documented cases of dysentery. flexner's dysentery lost the character of a mass ep ... | 1996 | 9027176 |
| computational neural networks for predictive microbiology. ii. application to microbial growth. | the growth of a specific microorganism on a certain food is influenced by a number of environmental factors such as temperature, ph, and salt concentration. methods that delineate the history of the growth of microorganisms are always subject to a considerable debate and scrutiny in the field of predictive microbiology. regardless of its types, a growth model (e.g., modified gompertz model) contains several parameters that vary depending on the microorganisms/food combination and the associated ... | 1997 | 9029255 |
| virulence gene deletion frequency is increased in shigella flexneri following conjugation, transduction, and transformation. | some commonly used methods for introducing dna provoke spontaneous loss of expression of a virulence gene located on the high molecular mass plasmid in shigella flexneri. the introduction of plasmid dna by calcium chloride-mediated transformation in strains harbouring wild-type or mutated copies of regulatory genes resulted in the loss of expression of an mxic-lacz reporter gene at high frequency, approaching 100% in some cases. lac- segregants arose whether or not the introduced plasmids harbou ... | 1997 | 9037774 |
| early feeding of an energy dense diet during acute shigellosis enhances growth in malnourished children. | in a controlled clinical trial, we examined the effect of the short-term feeding of an energy-dense milk cereal formula in malnourished children with clinically severe dysentery due to acute shigellosis. seventy-five malnourished children, aged 12-48 mo, passing blood or blood with mucous in the stool for < or = 96 h, were offered a hospital diet. in addition, study children (n = 36) were offered a milk-cereal formula with an energy of 5 kj/g (an 11% protein diet); similarly, control children (n ... | 1997 | 9040543 |
| entamoeba histolytica and entamoeba dispar infection in children in bangladesh. | the prevalence of infection by the invasive parasite entamoeba histolytica and the noninvasive parasite entamoeba dispar was determined in 2000 children in bangladesh. antigen detection identified more cases of e. histolytica-e. dispar infection than did culture or microscopy. microscopic identification of e. histolytica-e. dispar complex infection in stool did not equate with the diagnosis of amebic dysentery because most amebic infections in this population were due to e. dispar: urban childre ... | 1997 | 9041357 |
| pseudomonas aeruginosa b-band o-antigen chain length is modulated by wzz (ro1). | the wbp gene cluster, encoding the b-band lipopolysaccharide o antigen of pseudomonas aeruginosa serotype o5 strain pao1, was previously shown to contain a wzy (rfc) gene encoding the o-antigen polymerase. this study describes the molecular characterization of the corresponding wzz (rol) gene, responsible for modulating o-antigen chain length. p. aeruginosa o5 wzz has 19 to 20% amino acid identity with wzz of escherichia coli, salmonella enterica, and shigella flexneri. knockout mutations of the ... | 1997 | 9045803 |
| the hrpa and hrpc operons of erwinia amylovora encode components of a type iii pathway that secretes harpin. | a 6.2-kb region of dna corresponding to complementation groups ii and iii of the erwinia amylovora hrp gene cluster was analyzed. transposon mutagenesis indicated that the two complementation groups are required for secretion of harpin, an elicitor of the hypersensitive reaction. the sequence of the region revealed 10 open reading frames in two putative transcription units: hrpa, hrpb, hrcj, hrpd, and hrpe in the hrpa operon (group iii) and hrpf, hrpg, hrcc, hrpt, and hrpv in the hrpc operon (gr ... | 1997 | 9045830 |
| bacterial interspersed mosaic elements (bimes) are a major source of sequence polymorphism in escherichia coli intergenic regions including specific associations with a new insertion sequence. | a significant fraction of escherichia coli intergenic dna sequences is composed of two families of repeated bacterial interspersed mosaic elements (bime-1 and bime-2). in this study, we determined the sequence organization of six intergenic regions in 51 e. coli and shigella natural isolates. each region contains a bime in e. coli k-12. we found that multiple sequence variations are located within or near these bimes in the different bacteria. events included excisions of a whole bime-1, expansi ... | 1997 | 9055066 |
| [the enterosorption treatment of patients with acute intestinal infections and chronic colitis with diarrhea]. | a total of 234 patients with acute intestinal infections (aii) and chronic colitis presenting with diarrhoea were examined. in an acute phase of aii induced by conditionally pathogenic flora, salmonellae and shigellae, as well as in exacerbation of chronic colitis, blood aggregability appears to be on the increase, with the ability of erythrocytes to deformation getting worse. in rectal mucosa hemodynamic disorders are common, manifested by decrease in pulse blood filling, rate of bloodflow pred ... | 1996 | 9072235 |
| [bacterial antigenic structure of shigella flexneri serotype 1b and its 3b serotype mutant and susceptibility to bacterial action of complement in normal bovine serum]. | the susceptibility of s. flexneri 1b and 3b strains to killing action of serum was investigated. differences in sensitivity to bactericidal action of complement appeared to result from different structure of their lps-es. the protective effect of lps-es depends both on their origin and concentration. | 1996 | 9072769 |
| sopa, the outer membrane protease responsible for polar localization of icsa in shigella flexneri. | the spreading ability of shigella flexneri, a facultative intracellular gram-negative bacterium, within the host-cell cytoplasm is the result of directional assembly and accumulation of actin filaments at one pole of the bacterium. icsa/virg, the 120 kda outer membrane protein that is required for intracellular motility, is located at the pole of the bacterium where actin polymerization occurs. bacteria growing in laboratory media and within infected cells release a certain proportion of the sur ... | 1997 | 9076742 |
| influence of different rol gene products on the chain length of shigella dysenteriae type 1 lipopolysaccharide o antigen expressed by shigella flexneri carrier strains. | introduction of the rol genes of shigella dysenteriae 1 and escherichia coli k-12 into shigella flexneri carrier strains expressing the heterologous s. dysenteriae type 1 lipopolysaccharide resulted in the formation of longer chains of s. dysenteriae 1 o antigen. in bacteria producing both homologous and heterologous o antigen, this resulted in a reduction of the masking of heterologous o antigen by homologous lipopolysaccharide and an increased immune response induced by intraperitoneal immuniz ... | 1997 | 9079931 |
| identification of a shigella flexneri crir gene increasing ipa genes expression: a novel member of response regulators of the two-component signal transduction family. | a genetic locus named cri, which enhanced the expression of ipa genes, was cloned into escherichia coli k-12 from shigella flexneri 1b chromosomal dna. subcloning and tn5-tc1 transposon experiments showed that cri locus was located on a 2.6-kb hindiii fragment. nucleotide sequence analysis of the region revealed at least three open reading frames (orf), one of which, named crir, encoded a protein of 226 amino-acid residues and transcriptionally increased the ipab expression. the deduced regulato ... | 1996 | 9095416 |
| suicide plasmids containing promoterless reporter genes can simultaneously disrupt and create fusions to target genes of diverse bacteria. | we describe several plasmids that are designed to create fusions between chromosomal or plasmid-encoded genes and the lacz, phoa or gfp reporter genes. these plasmids all contain the vegetative origin of r6k, but lack the r6k pir gene, and therefore fail to replicate in strains lacking pir. fragments of target genes are introduced into these plasmids, and fusions are created in a single step as a consequence of (campbell-type) integration of the entire plasmid by homologous recombination. cloned ... | 1997 | 9099861 |
| [cases of gastroenteritis associated to vibrio cholerae no 01 in oran, salta]. | forty-one sporadic cases of non-o group 1 vibrio cholerae gastroenteritis were detected in orán, salta, between february 1992 and february 1995. the frequency of isolation was 0.9% of the diarrhea cases. out of 41 patients, 21 (51.2%) were older than 15 years and 25 (60.9%) were male. all the patients had diarrhea, 24 (58.5%) had watery stools and 6 (14.6%) cholera-like diarrhea; 10 (24.4%) presented vomiting and 12 (29%) mild dehydration. six malnourished children who suffered from diarrhea wit ... | 1996 | 9102658 |
| [the biological characteristics of shigella flexneri strains circulating in saint petersburg in 1992-1994]. | s.flexneri 2a strains isolated in 1992-1994 from 371 patients in sporadic cases, from 90 patients and their contacts in cases of group diseases and from 71 lethal cases of flexner's dysentery, were studied in comparison with strains isolated in 1980s. the study revealed the biological heterogeneity of s.flexneri 2a strains. the circulation of 3 enzymatic variants and 11 variants differing in their sensitivity to colicins from frederick's collection was established. the overwhelming majority of s ... | 1996 | 9103073 |
| ultrastructure of colony-like communities of bacteria. | colony-like communities are poorly studied forms of bacterial growth on agar. these communities are formed after the growth of large amounts of bacteria simultaneously plated onto a limited area of agar, while "classical" colonies are formed as a result of single bacterial cell multiplication. colony-like communities of gram-negative and gram-positive bacteria differ from "classical" microbial colonies in their ultrastructural organization. almost every cell in colony-like communities has an ind ... | 1997 | 9113071 |
| molecular epidemiology of multiply antibiotic-resistant shigella flexneri in fortaleza, brazil. | in northeastern brazil, strains of shigella flexneri resistant to multiple antibiotics are often found in patients in both urban areas and community hospitals. this study used pulsed-field gel electrophoresis (pfge) and plasmid analysis to further analyze the molecular epidemiology of shigella flexneri strains isolated from hospitals and an urban community in fortaleza, brazil. twenty-six strains of s. flexneri from three distinct areas in the city of fortaleza, brazil, were examined: 14 strains ... | 1997 | 9114381 |
| acid stress responses in enterobacteria. | the enteric microogranisms salmonella, escherichia coli and shigella flexneri prefer to grow in neutral ph environments. they nevertheless experience dramatic ph fluctuations in nature and during pathogenesis. in response to environmental encounters with acid, these organisms have evolved complex, inducible acid survival strategies. regulatory features include an alternative factor (sigma s), 2- component signal transduction systems (phop/q; mvia/?) and the major iron regulatory protein fur. spe ... | 1997 | 9119190 |
| human monocyte-derived macrophages infected with virulent shigella flexneri in vitro undergo a rapid cytolytic event similar to oncosis but not apoptosis. | infection of human monocyte-derived macrophages in vitro with virulent shigella flexneri resulted in cell death which involved rupture of the plasma membrane, cell swelling, disintegration of ultrastructure, and generalized karyolysis. these features bore resemblance to oncosis and are in striking contrast to previously described observations of mouse macrophages, where a similar infection by virulent shigella resulted in cell death by apoptosis. cell death by oncosis in human macrophages was co ... | 1997 | 9119491 |
| exploring the basis of peptide-carbohydrate crossreactivity: evidence for discrimination by peptides between closely related anti-carbohydrate antibodies. | to investigate the molecular basis of antigenic mimicry by peptides, we studied a panel of closely related mabs directed against the cell-wall polysaccharide of group a streptococcus. these antibodies have restricted v-gene usage, indicating a shared mechanism of binding to a single epitope. epitope mapping studies using synthetic fragments of the cell-wall polysaccharide supported this conclusion. all of the mabs isolated crossreactive peptides from a panel of phage-displayed libraries, and com ... | 1997 | 9122216 |
| functional analysis of the shigella flexneri ipac invasin by insertional mutagenesis. | the ability of shigella to enter epithelial cells, to escape from the phagocytic vacuole, and to induce apoptosis in macrophages requires the ipab, ipac, and ipad proteins. an extracellular complex containing ipab and ipac can promote the uptake of inert particles by epithelial cells. to determine whether the function of ipac is to act as an extracellular chaperone for ipab in the ipa complex or as an effector of entry involved in a direct interaction with the cell surface, we have constructed e ... | 1997 | 9125536 |
| characterization and quantitative analysis of serum igg class and subclass response to shigella sonnei and shigella flexneri 2a lipopolysaccharide following natural shigella infection. | the igg subclass response to shigella sonnei and shigella flexneri 2a lipopolysaccharide (lps) was examined in subjects naturally exposed to these organisms. affinity-purified lps antibodies obtained using a column of shigella lps bound to epoxy-activated sepharose 6b were used as standards to calibrate the serum antibody response to natural shigella infection. the geometric mean concentrations of specific igg in sera from those not exposed to shigella organisms were 7.9 microg/ml against s. son ... | 1997 | 9129076 |
| epidemiology of shigellosis among children exposed to cases of shigella dysentery: a multivariate assessment. | we followed 1,756 young, rural bangladeshi children less than five years of age for one month after identification of sentinel shigella patients in their neighborhoods. two hundred nineteen (12%) children developed shigella diarrhea (shigellosis) and 227 (13%) developed culture-negative dysentery. shigella flexneri (60%) and s. dysenteriae, type 1 (15%) were the most common isolates among shigellosis cases. within individual neighborhoods, there was poor agreement (kappa = 0.21) between shigella ... | 1997 | 9129527 |
| antigen-dependent b cell differentiation in the synovial tissue of a patient with reactive arthritis. | reactive arthritis (rea) can develop as a consequence of a bacterial infection with organisms such as chlamydia trachomata, shigella flexneri, or yersinia enterocolitica. although the mechanism underlying the induction of a chronic synovitis is unknown, the expression of hla-b27 seems to play a crucial role in the etiology of the disease. bacterial antigens induce a humoral immune response, but little is know about the impact of b cells on the inflammatory processes developing in the synovial me ... | 1997 | 9131588 |
| a rapid sample preparation method for pcr detection of food pathogens based on buoyant density centrifugation. | the use of buoyant density centrifugation (bdc) to prepare samples for pcr analysis of food pathogens is described. blue cheese and milk homogenates were inoculated with shigella flexneri and layered on top of percoll media. after bdc, the food homogenates remained in the upper part of the centrifuge tube, separated from the bacteria, which retained viability and were concentrated below the lighter percoll layer. pcr inhibitors stayed in the homogenate and pcr analyses of treated samples consist ... | 1997 | 9134780 |
| [rhabdomyolysis during shigella flexneri shigellosis]. | | 1996 | 9139203 |
| [morphologic characterization of the contemporary dysentery caused by shigella flexneri 2a]. | there is a tendency in st. petersburg since 1990s to an increase of dysentery morbidity and lethality mainly caused by flexner shigella 2a. morphology of the disease in adults is given on the material of 286 necropsies in 1993-1994 in the s. p. botkin infectious hospital. males (mean age 50 years) and among them chronic alcoholics prevailed; females (mean age 70 years) were frequently with a grave cardiovascular pathology. advanced inflammation (fibrinous, ulcerative and hemorrhagic) of all colo ... | 1997 | 9139607 |
| shigella actin-based motility in the absence of vinculin. | reports on the role of vasodilator-stimulated phosphoprotein (vasp) and proline-rich sequences in actin-based motility of listeria and potentially of shigella flexneri have led to the suggestion that vinculin might be an essential docking protein on the surface o2 motile shigella. therefore, whether vinculin had a functional role in shigella actin-based motility was tested by examining shigella infection of the vinculin-deficient f9 cell line variant 5.51. shigella are able to form actin tails a ... | 1997 | 9142438 |
| antibacterial effect of the adhering human lactobacillus acidophilus strain lb. | the spent culture supernatant of the human lactobacillus acidophilus strain lb produces an antibacterial activity against a wide range of gram-negative and gram-positive pathogens. it decreased the in vitro viability of staphylococcus aureus, listeria monocytogenes, salmonella typhimurium, shigella flexneri, escherichia coli, klebsiella pneumoniae, bacillus cereus, pseudomonas aeruginosa, and enterobacter spp. in contrast, it did not inhibit lactobacilli and bifidobacteria. the activity was heat ... | 1997 | 9145867 |
| characterization of the locus encoding the streptococcus pneumoniae type 19f capsular polysaccharide biosynthetic pathway. | we have previously reported the nucleotide sequence of the first six genes of the streptococcus pneumoniae type 19f capsular polysaccharide biosynthesis locus (cps19f). in this study we used plasmid insertion/rescue and inverse polymerase chain reaction (pcr) to clone an additional 10 kb downstream region containing the remainder of the cps19f locus, which was then subjected to sequence analysis. the cps19f locus is located in the s. pneumoniae chromosome between dexb and alia, and consists of 1 ... | 1997 | 9157246 |
| regulation of o-antigen chain length is required for shigella flexneri virulence. | it is shown that shigella flexneri maintains genetic control over the modal chain length of the o-antigen polysaccharide chains of its lipopolysaccharide (lps) molecules because such a distribution is required for virulence. the effect of altering o-antigen chain length on s. flexneri virulence was investigated by inserting a kanamycin (km)-resistance cassette into the rol gene (controlling the modal o-antigen chain length distribution), and into the rfbd gene, whose product is needed for synthe ... | 1997 | 9157247 |
| a transferable multiple drug resistance plasmid from vibrio cholerae o1. | ten multiple antimicrobial-resistant isolates of vibrio cholerae o1 isolated from patients in uganda were characterized, and the transferability of resistance to bacteria of diverse origins was investigated. the isolates were toxigenic and belonged to biotype e1 tor, serotype ogawa, and ribotype 8, and possessed a 130-mda plasmid of incompatibility group 6-c. this plasmid, designated prvc1, was shown to confer resistance to trimethoprim (mediated by a dhfri gene), sulfonamides (a suii gene), tet ... | 1995 | 9158776 |
| antibodies against bacterial lipopolysaccharides in japanese patients with ankylosing spondylitis. | we investigated igg, iga and igm class specific antibodies to five bacterial (klebsiella pneumoniae, escherichia coli, salmonella enteritidis, salmonella typhimurium and shigella flexneri) lipopolysaccharides (lps) by enzyme-linked immunosorbent assay in 144 japanese patients with ankylosing spondylitis (as). as patients had significantly elevated iga antibodies to k. pneumoniae lps, salmonella enteritidis lps and salmonella typhimurium lps; however, there was no correlation between antibody lev ... | 1997 | 9159547 |
| construction and characterization of a live attenuated vaccine candidate against shigella dysenteriae type 1. | vaccine candidates against shigella dysenteriae type 1, which is associated with the most severe cases of bacillary dysentery, were constructed. the rfp and rfb gene clusters, which code for s. dysenteriae 1 o antigen biosynthesis, were randomly integrated into either the chromosome or the virulence plasmid of the rough attenuated shigella flexneri arod strain sfl124-27 with a minitransposon carrying an arsenite resistance selection marker. the recombinant clones efficiently expressed the recomb ... | 1997 | 9169740 |
| characterization of shigella type 1 fimbriae: expression, fima sequence, and phase variation. | this study documents the presence of type 1 fimbriae on shigella and confirms these mannose-sensitive adherence structures to be bona fide components of the shigella surface. while laboratory-passaged shigella strains and lyophilized clinical isolates failed to express type 1 fimbriae, 6 of 20 recent clinical isolates, including 4 shigella flexneri strains, 1 shigella boydii strain, and 1 shigella dysenteriae strain, produced type 1 fimbriae as detected by mannose-sensitive hemagglutination (msh ... | 1997 | 9169792 |
| plasmid maintenance functions of the large virulence plasmid of shigella flexneri. | the large virulence plasmid pmysh6000 of shigella flexneri contains a replicon and a plasmid maintenance stability determinant (stb) on adjacent sali fragments. the presence of a repfiia replicon on the sali c fragment was confirmed, and the complete sequence of the adjacent sali o fragment was determined. it shows homology to part of the transfer (tra) operon of the f plasmid. stb stabilizes a partition-defective p1 miniplasmid in escherichia coli. a 1.1-kb region containing a homolog of the f ... | 1997 | 9171415 |
| effect of shigella enterotoxin 1 (shet1) on rabbit intestine in vitro and in vivo. | shigella enterotoxin 1 is a novel enterotoxin elaborated by shigella flexneri 2a that causes fluid accumulation in rabbit ileal loops and a rise in short circuit current in ussing chambers. | 1997 | 9176079 |
| modulation of bacterial entry into epithelial cells by association between vinculin and the shigella ipaa invasin. | shigella flexneri is the causative agent of bacillary dysentery in humans. shigella invasion of epithelial cells is characterized by cytoskeletal rearrangements and formation of cellular projections engulfing the bacterium in a macropinocytic process. we show here that vinculin, a protein involved in linking actin filaments to the plasma membrane, is a direct target of shigella during cell invasion. ipaa, a shigella protein secreted upon cell contact, rapidly associates with vinculin during bact ... | 1997 | 9184218 |
| antibiotic resistance pattern of vibrio cholerae and shigella causing diarrhoea outbreaks in the eastern africa region: 1994-1996. | between march 1994 and december 1996, 1797 rectal swabs were transported to the amref laboratory from sites in six countries in the eastern africa region: 1749 were cultured for vibrio cholerae and 48 for shigella/salmonella. culture, isolation, identification and antibiotic susceptibility testing were performed using standardized techniques. the isolates were categorized as sensitive or resistant based on standardized zones of inhibition. the rate of isolation of v. cholerae from rectal swabs i ... | 1997 | 9185422 |
| enterohaemorrhagic escherichia coli in central african republic. | a dysentery outbreak in the central african republic village of zemio was diagnosed as "shigella flexneri" by the pasteur institute in bangui (ipb) in february 1996; 2 months later there was an outbreak of hemorrhagic colitis. 108 patients presented with bloody diarrhea; cramping abdominal pain, fever, nausea, and vomiting were uncommon. the illness lasted between 5 days and 3 weeks (average, 8 days). antibiotics were ineffective. four patients died and several developed hemolytic-uremic syn ... | 1997 | 9186391 |
| construction and characterization of genetically-marked bivalent anti-shigella dysenteriae 1 and anti-shigella flexneri y live vaccine candidates. | bivalent vaccine candidates were developed against shigella dysenteriae 1 and shigella flexneri, which are among the most frequent causative agents of shigellosis in developing countries. the rfp and rfb gene clusters, which code for s. dysenteriae serotype 1 o-antigen biosynthesis, were inserted into an arsenite resistance minitransposon and randomly integrated into the attenuated s. flexneri arod serotype y strain sfl124. nine recombinant clones that efficiently expressed both homologous and h ... | 1997 | 9188091 |
| structures of the reduced and mercury-bound forms of merp, the periplasmic protein from the bacterial mercury detoxification system. | bacteria carrying plasmids with the mer operon, which encodes the proteins responsible for the bacterial mercury detoxification system, have the ability to transport hg(ii) across the cell membrane into the cytoplasm where it is reduced to hg(0). this is significant because metallic mercury is relatively nontoxic and volatile and thus can be passively eliminated. the structures of the reduced and mercury-bound forms of merp, the periplasmic protein, which binds hg(ii) and transfers it to the mem ... | 1997 | 9188683 |
| [ultrastructure of bacterial fimbriae in e. coli and sh. flexneri]. | | 1966 | 9190153 |
| effect of mutations in shigella flexneri chromosomal and plasmid-encoded lipopolysaccharide genes on invasion and serum resistance. | this study shows that both length and distribution of lipopolysaccharide (lps) are important for shigella flexneri invasion and virulence. mutants were generated in the chromosomal lps synthesis genes rfa, rfb, and rol, and in a plasmid-encoded o-antigen chain-length regulator, cld(phs-2). lps analysis showed that mutations in rfb genes and in a candidate rfal gene either eliminated the entire o-antigen side chains or produced chains of greatly reduced length. mutation in a previously unidentifi ... | 1997 | 9194705 |
| nested polymerase chain reaction strategy simultaneously targeting dna sequences of multiple bacterial species in inflammatory joint diseases. i. screening of synovial fluid samples of patients with spondyloarthropathies and other arthritides. | bacteria play a crucial pathogenetic role in lyme arthritis (la), reactive arthritis (rea), other forms of spondyloarthropathy (spa), and possibly in undifferentiated oligoarthritis (uoligo). polymerase chain reaction (pcr) technology has been applied to detect bacterial dna of individual microbes in synovial fluid (sf) of patients with arthritides. we screened for dna sequences of 8 bacterial species simultaneously in sf of patients with inflammatory joint disease. | 1997 | 9195515 |
| nested polymerase chain reaction strategy simultaneously targeting dna sequences of multiple bacterial species in inflammatory joint diseases. ii. examination of sacroiliac and knee joint biopsies of patients with spondyloarthropathies and other arthritides. | bacteria play a crucial pathogenetic role in reactive arthritis (rea) and other forms of spondyloarthropathy (spa) and in lyme arthritis. although there is evidence of local persistence of bacterial antigens no definitive method revealing microbes in peripheral joints has been established. we detected dna of individual bacteria in synovial material by pcr. applying molecular technology we screened simultaneously for 8 bacterial genomes in arthritis and sacroiliitis. | 1997 | 9195516 |
| identification of a chromosomal shigella flexneri multi-antibiotic resistance locus which shares sequence and organizational similarity with the resistance region of the plasmid nr1. | the ampicillin resistance gene from shigella flexneri 2a strain ysh6000 was cloned and shown by southern hybridization analysis to be closely linked to the previously cloned streptomycin, chloramphenicol, and tetracycline resistance determinants, which are borne on a chromosomally integrated 99-kb element. analysis of this chromosomal multi-antibiotic resistance locus revealed that it had a high level of sequence and organizational similarity to an equivalent region of the shigella r-plasmid, nr ... | 1997 | 9200219 |
| clinical isolates of shigella species induce apoptosis in macrophages. | shigella species are invasive enterobacteria that cause dysentery, a severe form of diarrhea. the ability to invade epithelial cells and to kill macrophages is essential for virulence in a prototype shigella flexneri strain. it is shown here that clinical isolates of both s. flexneri and shigella sonnei invade epithelial cells and are cytotoxic to macrophages in vitro. furthermore, clinical shigella strains kill macrophages by inducing apoptosis. the conservation of the ability to induce macroph ... | 1997 | 9203676 |
| identification of a fourth gene involved in dtdp-rhamnose synthesis in streptococcus mutans. | we had isolated three genes (rmla, rmlb, and rmlc) involved in dtdp-rhamnose synthesis in streptococcus mutans and found that three genes were insufficient for dtdp-rhamnose synthesis (y. tsukioka, y. yamashita, t. oho, y. nakano, and t. koga, j. bacteriol. 179:1126-1134, 1997). the rmld gene of s. mutans, encoding the enzyme which catalyzes the last step of dtdp-rhamnose synthesis, has been cloned and sequenced. the cell extract of escherichia coli expressing the rmld gene of s. mutans exhibite ... | 1997 | 9209063 |
| the human lactobacillus acidophilus strain la1 secretes a nonbacteriocin antibacterial substance(s) active in vitro and in vivo. | the adhering human lactobacillus acidophilus strain la1 inhibits the cell association and cell invasion of enteropathogens in cultured human intestinal caco-2 cells (m. f. bernet, d. brassard, j. r. neeser, and a. l. servin, gut 35:483-489, 1994). here, we demonstrate that strain la1 developed its antibacterial activity in conventional or germ-free mouse models orally infected by salmonella typhimurium. we present evidence that the spent culture supernatant of strain la1 (la1-scs) contained anti ... | 1997 | 9212421 |
| [methodological approaches to the study and prevention of shigellosis among the troops]. | in article the methodical approaches to study of regularity of occurrence and distribution of shigellosis are revealed from positions of the theory of etiologic selectivity of main ways of transfers, its unequivalentness at the various nosologic forms of dysentery. a complex of antiepidemiologic measures under conditions of means of prophylaxis is proved. on the basis of analysis of etiologic structure of shigellosis a main problem of the armed forces, causing dysentery is designated. | 1997 | 9221595 |
| [shigellosis in moscow: new trends in the epidemiological process and their social determinants]. | in moscow for a long time morbidity in acute enteric infections, and in shigella infections as their main constituent, steadily decreased. in recent years the opposite tendency was noted: a rise in morbidity. a pronounced tendency for shigella infections, especially flexner's dysentery, to affect older ages was observed. new risk groups, including adults busy in "shuttle" commerce and different asocial elements, appeared. the number of lethal cases considerably increased. unusual manifestations ... | 1997 | 9221653 |
| shigella septicaemia in an infant. | | 1997 | 9230585 |
| to sting or be stung: bacteria-induced apoptosis. | | 1997 | 9234503 |
| further search for virulence factors encoded by salmonella serovar-specific plasmids. | the so called salmonella virulence plasmids which are specifically prevalent among some of the s. enterica serovars were shown to contribute only marginally to the virulence make-up of salmonella, which is in contrast to shigella and yersinia spp. the experiments reported in this paper failed to find encoded plasmid factors which contribute to serum resistance, surface antigens, immunoinsufficiency or to up-regulation of chromosomally encoded factors such as toxins, surface antigens etc. taking ... | 1997 | 9241803 |
| development of resistance in shigella flexneri isolates obtained in the past 20 years in eastern romania. | our study is focused on the antimicrobial activity for a number of 626 shigella flexneri strains collected from epidemic outbreaks and hospitalised patients during 1976-1995 period, in eastern romania. the metodology used for determining the in vitro activity of the antimicrobials was that described by nccls. the agents which are currently used in therapy (ampicillin, tetracycline, chloramphenicol) are less active than the newer drugs (third generation cephalosporins, aztreonam, imipenem, ciprof ... | 1996 | 9256026 |
| the molecular epidemiology of trimethoprim-sulphamethoxazole- resistance of shigella flexneri in the trakya region of turkey. | trimethoprim-sulphamethoxazole (sxt) resistance increased among shigella flexneri isolates in 1995 relative to previous years, in the trakya region, the european part of turkey. since this region is the entrance to turkey from northern countries, a heavy traffic of travellers passing through should have been importing or exporting the resistant isolates. we studied the genetic basis and epidemiology of this resistance and monitored the clonal changes which have taken place in the meanwhile. duri ... | 1997 | 9258942 |
| virulence plasmid instability in shigella flexneri 2a is induced by virulence gene expression. | expression of the predominantly plasmid-encoded virulence regulon of shigella flexneri 2a is induced by growth at 37 degrees c and repressed by growth at 30 degrees c. during growth at 37 degrees c, spontaneous s. flexneri mutants arise which have undergone virulence plasmid curing or rearrangement and no longer display the virulent phenotype. in the laboratory, the unstable nature of the virulence plasmid causes complete loss of virulence in a growing population. we have undertaken an analysis ... | 1997 | 9284138 |
| the modified nucleoside 2-methylthio-n6-isopentenyladenosine in trna of shigella flexneri is required for expression of virulence genes. | the virulence of the human pathogen shigella flexneri is dependent on both chromosome- and large-virulence-plasmid-encoded genes. a kanamycin resistance cassette mutation in the miaa gene (miaa::km sma), which encodes the trna n6-isopentyladenosine (i6a37) synthetase and is involved in the first step of the synthesis of the modified nucleoside 2-methylthio-n6-isopentenyladenosine (ms2i6a), was transferred to the chromosome of s. flexneri 2a by phage p1 transduction. in the wild-type bacterium, m ... | 1997 | 9294434 |
| [hygienic aspects of water quality from the danube river in novi sad]. | in order to assess the water quality of the danube river during the bathing season (june, 15. -september, 15.) from 1992-1995, water was examined every day (bacteriologically and chemically) while "big chemistry", hybrid analysis and determination of physiologic groups were performed every other week at the locality of the most beautiful beach called strand in novi sad. analyses showed that water did not meet criteria of the ii class quality in regard to microbiologic requirements in 63.44% of s ... | 1997 | 9297048 |
| vinculin proteolysis unmasks an acta homolog for actin-based shigella motility. | to generate the forces needed for motility, the plasma membranes of nonmuscle cells adopt an activated state that dynamically reorganizes the actin cytoskeleton. by usurping components from focal contacts and the actin cytoskeleton, the intracellular pathogens shigella flexneri and listeria monocytogenes use molecular mimicry to create their own actin-based motors. we raised an antibody (designated fs-1) against the fefpppptde sequence of listeria acta, and this antibody: (a) localized at the tr ... | 1997 | 9298981 |
| active site peptide of beta-lactamase from shigella flexneri ucsf-129. | the peptide containing the catalytic serine of beta-lactamase from shigella flexneri was determined as v-d-e-r-f-p-m-m-s*-t-f-k. it is a local pathogenic strain which produces intestinal problems, especially in children. the highly purified enzyme was prepared by affinity chromatography in phenylboronic acid-agarose gels. the peptide was obtained by tryptic hydrolysis, with further purification by bio-gel p-4, sephadex qae-25 and sephadex sp-25. the relevance of the serine, lysine and arginine r ... | 1997 | 9301069 |
| disruption of icsp, the major shigella protease that cleaves icsa, accelerates actin-based motility. | shigella pathogenesis involves bacterial invasion of colonic epithelial cells and movement of bacteria through the cytoplasm and into adjacent cells by means of actin-based motility. the shigella protein icsa (virg) is unipolar on the bacterial surface and is both necessary and sufficient for actin-based motility. icsa is inserted into the outer membrane as a 120-kda polypeptide that is subsequently slowly cleaved, thereby releasing the 95-kda amino-terminal portion into the culture supernatant. ... | 1997 | 9302008 |
| evaluation of antibodies reactive with campylobacter jejuni in egyptian diarrhea patients. | serum and stool samples were collected from 128 individuals: 96 diarrhea patients and 32 apparently healthy controls. stool specimens were cultured for enteric bacterial pathogens, while sera were screened by enzyme-linked immunosorbent assay for campylobacter jejuni-reactive antibodies. of 28 diarrhea patients who demonstrated c. jejuni-reactive antibodies (titers, > 100), 14 were culture positive for this organism. the 32 healthy controls showed significantly lower antibody titers (p < 0.05) w ... | 1997 | 9302201 |
| shigella flexneri type-specific antigen v: cloning, sequencing and characterization of the glucosyl transferase gene of temperate bacteriophage sfv. | with lysogeny by bacteriophage sfv, shigella flexneri serotype y is converted to serotype 5a. the glucosyl transferase gene (gtr) from bacteriophage sfv of s. flexneri, involved in serotype-specific conversion, was cloned and characterized. the dna sequence of a 3.7 kb ecori-bamhi fragment of bacteriophage sfv which includes the gtr gene was determined. this gene, encoding a polypeptide of 417 aa with 47.67 kda molecular mass, caused partial serotype conversion of s. flexneri from serotype y to ... | 1997 | 9305766 |
| molecular characterization of the genes involved in o-antigen modification, attachment, integration and excision in shigella flexneri bacteriophage sfv. | bacteriophage sfv is a temperate phage of shigella flexneri responsible for converting serotype y (3,4) to serotype 5a (v; 3,4) through its glucosyl transferase gene. the glucosyl transferase (gtr) gene of sfv has been cloned and shown to partially convert s. flexneri serotype y to serotype 5a. in this study, we found that the serotype-converting region of sfv was approximately 2.5 kb in length containing three continuous orfs. the recombinant strain carrying the three complete orfs expressed th ... | 1997 | 9305767 |
| multiple drug-resistant shigella dysenteriae type 1 in rajbari district, bangladesh. | twenty-one shigellae isolates were obtained from bloody faecal specimens of diarrhoeal patients at rajbari district hospital from january 1994 to june 1995, and serogrouped. fourteen (67%) isolates belonged to the shigella dysenteriae serogroup and 7 (33%) to shigella flexneri serogroup. shigella dysenteriae strains were further serotyped; all were shigella dysenteriae 1. each strain was tested for resistance to 6 common antimicrobial agents. the two strains had different antibiotic susceptibili ... | 1997 | 9308296 |
| induction of gram-negative bacterial growth by neurochemical containing banana (musa x paradisiaca) extracts. | bananas contain large quantities of neurochemicals. extracts from the peel and pulp of bananas in increasing stages of ripening were prepared and evaluated for their ability to modulate the growth of non-pathogenic and pathogenic bacteria. extracts from the peel, and to a much lesser degree the pulp, increased the growth of gram-negative bacterial strains escherichia coli o157:h7, shigella flexneri, enterobacter cloacae and salmonella typhimurium, as well as two non-pathogenic e. coli strains, i ... | 1997 | 9311120 |
| secretion of ipa proteins by shigella flexneri: inducer molecules and kinetics of activation. | the type iii mxi-spa secretion machinery of shigella flexneri is responsible for secretion of ipa proteins, which are involved in the entry of bacteria into epithelial cells. ipa proteins accumulate within bacteria growing in laboratory media, and their secretion is activated upon contact of bacteria with eukaryotic cells. in this study, we have identified a group of chemical compounds, including congo red, evans blue, and direct orange, which are able to induce secretion of ipa proteins by bact ... | 1997 | 9316999 |
| the mechanism of cell death in listeria monocytogenes-infected murine macrophages is distinct from apoptosis. | various pathogenic bacteria with the capacity to live within eukaryotic cells activate an apoptotic program in infected host cells. induction of apoptosis by listeria monocytogenes in murine dendritic cells and hepatocytes has been described. here we address the questions of whether and how the pathogen kills macrophages, its most important habitat. employing several complementary techniques aimed at discriminating between apoptosis and necrosis, we show that murine bone marrow-derived macrophag ... | 1997 | 9317010 |
| lipopeptides of borrelia burgdorferi outer surface proteins induce th1 phenotype development in alphabeta t-cell receptor transgenic mice. | induction of the appropriate t helper cell (th) subset is crucial for the resolution of infectious diseases and the prevention of immunopathology. some pathogens preferentially induce th1 or th2 responses. how microorganisms influence th phenotype development is unknown. we asked if borrelia burgdorferi, the spirochete which causes lyme arthritis, can promote a cytokine milieu in which t cells which are not specific for b. burgdorferi are induced to produce proinflammatory cytokines. using alpha ... | 1997 | 9317013 |