| [epidemiological study of shigella dysenteriae 1 in 2 communities of the guanacaste province, costa rica, 1975]. | | 1976 | 136972 |
| the pathogenesis of shigella diarrhea. v. relationship of shiga enterotoxin, neurotoxin, and cytotoxin. | the biological activity of the enterotoxin of shigella dysenteriae 1 was compared with that of a well-studied 20-year-old partially purified preparation of neurotoxin from the same organism. enterotoxicity, neurotoxicity, and cytotoxicity were present to an equivalent extent in both preparations. human convalescent antisera and experimental rabbit antisera had equal toxin-neutralizing antibody to the cytotoxic activity in these toxin preparations. multiple protein bands were present in each toxi ... | 1975 | 236346 |
| biological properties of shigella flexneri 2a toxin and its serological relationship to shigella dysenteriae 1 toxin. | a toxin extracted from heat-inactivated, alkaline-treated shigella flexneri 2a showed biological properties similar to those of shigella dysenteria 1 toxin. the s, flexneri 2a toxin was lethal to mice, enterotoxic for ileal loops of rabbits, and cytotoxic for hela cells. a serological relationship between s. flexneri 2a and s. dysenteriae 1 toxin was shown with cross neutralization tests. | 1977 | 323142 |
| the pathogenesis of shigella diarrhea. vi. toxin and antitoxin in shigella flexneri and shigella sonnei infections in humans. | two strains of shigella flexneri and one of shigella sonnei were studied for toxin production in vitro. all of the three strains produced a cell-free cytotoxin that showed marked similarity to that produced by shigella dysenteriae 1. each toxin eluted in two distinct peaks on chromatography with sephadex g-150, was destroyed by heating at 90 c for 30 min, and was neutralized by s. dysenteriae 1 antitoxin. patients with infections due to s. flexneri and s. sonnei developed antibody that neutraliz ... | 1977 | 323376 |
| toxin from the culture filtrate of shigella dysenteriae that causes morphological changes in chinese hamster ovary cells and is distinct from the neurotoxin. | a toxin that causes morphological changes in chinese hamster ovary cells was isolated from a culture filtrate of shigella dysenteriae 1. it was partially purified by successive column chromatography on diethylaminoethyl-cellulose, bio-gel a-5m, and hydroxylapatite. the toxin was separated from neurotoxin by diethylaminoethyl-cellulose column chromatography and was not lethal for mice. | 1977 | 336549 |
| effects of certain cations (fe, zn, mg, and ca) on bacterial endotoxins. | the natural occurrence of cations fe, zn, mg, and ca in the lipopolysaccharide (lps) of both the s and r forms of shigella dysenteriae 1 was studied. lps preparations were obtained either by phenol-water extraction (according to the method of westphal et al., z. naturforsch. 7b:148-155, 1952) or by extraction of cells with hypertonic sodium chloride-sodium citrate (according to the method of raynaud and digeon, c. r. acad. sci. (paris) 229:564-566, 1949), with subsequent chromatographic purifica ... | 1978 | 357292 |
| shigella dysenteriae 1-like cytotoxic enterotoxins produced by salmonella strains. | a salmonella enteritidis strain produced a cytotoxin in addition to heat-labile (lt) and heat-stable (st) enterotoxins. two strains of serotypes salmonella kapemba and salmonella thompson were lt and st negative, but exhibited a cytotoxic effect. after sephadex g-100 fractionation of the crude s. enteritidis material, some high and low molecular fractions had both cytotonic and cytotoxic activities. of the two other salmonellae, only some high molecular fractions contained the cytotoxic substanc ... | 1979 | 396765 |
| diagnostic value of indirect hemagglutination in the seroepidemiology of shigella infections. | to evaluate the usefulness of the indirect hemagglutination (iha) test in the epidemiological investigation of shigellosis, single serum specimens were tested from 50 patients with shigella dysenteriae 1 (shiga bacillus) infections, 103 asymptomatic contacts of these cases, 267 adult and 100 student control, and serum specimens collected during two outbreaks caused by s. sonnei and one outbreak due to s. flexneri 6. in patients with s. dysenteriae 1, 74% demonstrated titers of greater than or eq ... | 1976 | 767361 |
| inhibition of in vitro protein synthesis by shigella dysenteriae 1 toxin. | | 1976 | 786292 |
| the influence of some cations on bacterial endotoxins: copper. | in the course of its isolation and purification, bacterial endotoxin may be contaminated by some inorganic cations. the present study was concerned with cu-2+ contamination of the lipopolysaccharide-protein complex (lps) extracted from shigella dysenteriae 1 s and r strains. the cu-2+ contamination level of lps prepared by raynaud's method and partly purified through sephadex g200 and sepharose 4b was in the range of 1-5 mug cu-2+/mg lps. crude raynauds extract, similarly as lps prepared by west ... | 1975 | 808051 |
| studies on shigella isolated in southern taiwan. | during 1969, a total of 1,476 fecal and rectal swab specimens was collected from children with diarrhea and 249 strains of shigella were isolated. the incidence was 16.9%. the serotypes of 249 strains were: shigella dysenteriae, 1.6% (4 strains); s. flexneri, 73.1% (182 strains); s. boydii, 3.2 (8 strains) and s. sonnei, 22.1% (55 strains). there was no marked difference of the isolation rate throughout the whole year. the susceptibility of shigella isolates to chemotherapeutic agents were also ... | 1976 | 1036983 |
| some immunochemical and chemical aspects of s and r shigella dysenteriae 1 endotoxins. | endotoxins of s and r forms of shigella dysenteriae 1 were prepared by nacl-na citrate extraction, purified by gel chromatography on sephadex g 200 and on sepharose 4b and subjected to immunochemical and chemical analysis. the toxins contained 25--30% of lipids, 40--50% of carbohydrates and 14--24% of protein. the lipid and protein moieties of the lipopolysaccharide-protein complexes exhibited no significant difference, whereas the sugar moieties differed markedly (both qualitatively and quantit ... | 1975 | 1102598 |
| pathogenesis of shigella diarrhea. serum anticytotoxin antibody response produced by toxigenic and nontoxigenic shigella dysenteriae 1. | the serum antitoxin response to the cytotoxin contained in preparations of shigella dysenteriae 1 (shiga's bacillus) exotoxin was studied in natural and experimental infections of man. natural infection resulted in the rapid appearance of toxin-neutralizing antibody, which disappeared some time between 9 and 18 mo after infection. experimental infection of human volunteers provided the opportunity to study immunoglobulin class of the antibody in sera obtained serially from 7 to 50 days after inf ... | 1976 | 1107354 |
| a 4-kilobase congo red binding plasmid dna fragment of shigella dysenteriae 1 suppresses the growth and cell differentiation in escherichia coli. | a 4-kilobase congo red binding plasmid dna fragment of pcat 120 of shigella dysenteriae 1 was transferred to an escherichia coli k12 strain by transformation. transformants were unable to grow in any liquid broth medium. electron microscopic studies revealed that the transformants grown on tryptic soy agar were associated in clusters after cell division. normal cell separation among the transformants in comparison with recipient e. coli k12 was only observed when the growth medium was supplement ... | 1992 | 1307443 |
| role of escherichia coli k-12 rfa genes and the rfp gene of shigella dysenteriae 1 in generation of lipopolysaccharide core heterogeneity and attachment of o antigen. | the rfp gene of shigella dysenteriae 1 and the rfa genes of escherichia coli k-12 and salmonella typhimurium lt2 have been studied to determine their relationship to lipopolysaccharide (lps) core heterogeneity and their role in the attachment of o antigen to lps. it has been inferred from the nucleotide sequence that the rfp gene encodes a protein of 41,864 da which has a structure similar to that of rfag protein. expression of this gene in e. coli k-12 results in the loss of one of the three ba ... | 1992 | 1385388 |
| identification of a b subunit gene promoter in the shiga toxin operon of shigella dysenteriae 1. | the shiga toxin operon (stx) is composed of a and b subunit genes which are transcribed as a bicistronic mrna from a promoter which lies 5' to the stxa gene. northern (rna) blot and primer extension analyses revealed the existence of a second stxb gene transcript. recombinant plasmids which carried the stxb gene without the stx operon promoter and with the influence of a vector promoter abrogated produced stx b polypeptides, suggesting that the stxb gene mrna was transcribed from an independent ... | 1992 | 1400202 |
| decreased food intake in children with severe dysentery due to shigella dysenteriae 1 infection. | factors that affect food intake in acute shigellosis were studied in 82 children aged 24-59 months. children were offered an energy-dense milk-cereal-oil-based diet every 2 h. food intake was compared between children with shigella dysenteriae 1 infection and those infected with other shigella spp (predominantly s. flexneri). mean energy intake in the first 48 h was 435 kj/kg.d in children infected with s. dysenteriae 1 and 536 kj/kg.d in children infected with other shigella spp (p < 0.001). fe ... | 1992 | 1425537 |
| serological diagnosis of infection by shigella dysenteriae-1 in patients with bacillary dysentery. | a total of 192 samples of serum from 113 sri lankan patients with clinical dysentery was examined for antibodies of the igm class to the lipopolysaccharides (lpss) of shigella dysenteriae-1 and escherichia coli o157:h7. by means of elisa and immunoblotting, 59 patients were found to have serum antibodies to the lps of s. dysenteriae-1 only. four samples from one patient were found to contain serum antibodies to the lpss of both s. dysenteriae-1 and e. coli o157:h7. antibodies to the lps of s. dy ... | 1992 | 1474263 |
| fluorescent antibody staining test for rapid diagnosis of shigella dysenteriae 1 infection. | an indirect fluorescent antibody test for rapid detection of shigella dysenteriae 1 in diarrheal stools was developed. a diagnosis could be made within 90 min of submission of specimens to the laboratory. on comparison with culture results, the test had a sensitivity of 92%, a specificity of 93%, and positive and negative predictive values of 94% and 92%, respectively. | 1992 | 1611852 |
| antibodies to shiga holotoxin and to two synthetic peptides of the b subunit in sera of patients with shigella dysenteriae 1 dysentery. | acute- and convalescent-phase sera from 18 thai patients and convalescent-phase sera from two israeli patients and one bangladeshi patient with shigella dysenteriae 1 (shiga) dysentery were tested by enzyme-linked immunosorbent assay to detect antibodies that bind s. dysenteriae lipopolysaccharide (lps), shiga holotoxin, or two synthetic peptides representing epitopes from the b subunit of shiga toxin. paired sera from 24 maryland adults with shigella flexneri 2a or shigella sonnei diarrhea serv ... | 1992 | 1629317 |
| construction of stable lamb-shiga toxin b subunit hybrids: analysis of expression in salmonella typhimurium aroa strains and stimulation of b subunit-specific mucosal and serum antibody responses. | the complete shiga toxin b subunit and two n-terminal segments of the b subunit have been inserted into a cell surface exposed loop of the lamb protein, and expression of the hybrid proteins from three different promoter systems, i.e., (i) an in vitro-inducible tac promoter that provides high-level expression, (ii) the iron-regulated aerobactin promoter presumably induced in vivo under the iron-limiting conditions of the intestinal mucosal environment, and (iii) a synthetic, modified beta-lactam ... | 1992 | 1639503 |
| gene transfer in enteric bacteria through the formation of r-prime plasmids by an rp4: :mini-mu element. | gene transfer in seven pathogenic enteric bacteria was studied using an rp4: :mini-mu element, the plasmid pulb113. from the e. coli k-12 host strain the plasmid could be efficiently transferred to these enteric bacteria, but its transfer back to e. coli k-12 was not as efficient, being detected only in shigella dysenteriae 1, s. flexneri and the 'smooth' variant of s. sonnei. in these three species, transposition of chromosomal fragments into the plasmid to produce r-prime plasmid was also dete ... | 1991 | 1661362 |
| prospective hospital based study on persistent diarrhoea. | a total of 383 children aged less than 5 years suffering from acute watery diarrhoea or dysentery were studied in hospital to determine the rate of persistent diarrhoea. altogether 335 (87.5%) recovered within 13 days. only in 48 (12.5%) did the diarrhoea continue for 14 days or more, and they were considered as having persistent diarrhoea. children aged between 7 and 18 months had a significantly increased incidence of persistent diarrhoea. children suffering from grade ii-iv malnutrition const ... | 1991 | 1855686 |
| haemolytic uraemic syndrome in children. | of the 4070 children admitted in the department of paediatrics, 830 (24%) presented with diarrhoea. eleven of these had haemolytic ureamic syndrome (hus) characterised by microangiopathic haemolytic anaemia, thrombocytopenia and acute renal failure. only 3 had positive stool cultures (e. coli 2, shigella dysenteriae 1). two children expired while the rest recovered with conservative management and peritoneal dialysis. thus hus should be remembered as a complication of diarrhoea and a cause of ac ... | 1991 | 1861343 |
| endocytosis and intracellular transport of the glycolipid-binding ligand shiga toxin in polarized mdck cells. | the glycolipid-binding cytotoxin produced by shigella dysenteriae 1, shiga toxin, binds to mdck cells (strain 1) only after treatment with short-chain fatty acids like butyric acid or with the tumor promoter 12-o-tetradecanoylphorbol 13-acetate. the induced binding sites were found to be functional with respect to endocytosis and translocation of toxin to the cytosol. glycolipids that bind shiga toxin appeared at both the apical and the basolateral surface of polarized mdck cells grown on filter ... | 1991 | 1901867 |
| new trends in the use of al(oh)3-conjugated endotoxins and their subunits from the s- and r-forms of shigella dysenteriae serovar 1 for model vaccination purposes. | the lipopolysaccharides, lipopolysaccharide-protein complexes and their lipids a, isolated from shigella dysenteriae 1, exhibited lethal toxicity (ld50 300-400 micrograms per mouse), pyrogenicity (0.01-1.0 microgram), activity in the limulus test (10(-3)-10(-12) mg ml-1) and produced a positive local shwartzman reaction. it was found that these substances bound to al(oh)3 were capable of successfully protecting mice from challenge with both homologous and heterologous infections (up to 90% of mi ... | 1991 | 1905447 |
| unusual association of a plasmid with nalidixic acid resistance in an epidemic strain of shigella dysenteriae type 1 from asia. | the association of a 20-mda plasmid with nalidixic acid resistant (nalr) strains of shigella dysenteriae 1 has been examined. the plasmid, which is readily transferable, does not itself code for nalidixic acid resistance but offers a survival advantage to its host under nalidixic acid stress. the plasmid-containing cultures of s. dynsenteriae 1 produced nalr mutants in vitro at a frequency 1000-fold higher than their plasmidless parent strains, after two exposures to nalidixic acid. using a simi ... | 1991 | 2021898 |
| efficacy of aqueous extract of garlic & allicin in experimental shigellosis in rabbits. | the aqueous extract of garlic (allium sativum) and allicin both showed significant in vitro antibacterial activity against isolates of multiple drug-resistant shigella dysenteriae 1, sh. flexneri y, sh. sonnei and enterotoxigenic escherichia coli. the minimum inhibitory concentrations of the aqueous extract and allicin against sh. flexneri y were 5 and 0.4 microliters/ml, respectively. the two agents also showed promising in vivo antibacterial activity against sh. flexneri y when tested in the r ... | 1991 | 2022399 |
| epidemiologic aspects of shigellosis and other causes of dysentery in thailand. | nearly 20% of children seen in the outpatient department of children's hospital in bangkok, thailand, for diarrheal disease had bloody diarrhea. shigella species and enteroinvasive escherichia coli--isolated from 13% and 2% of children with diarrhea, respectively--were the most frequent causes of bloody diarrhea. campylobacter species and nontyphoidal salmonella species were also isolated frequently but were much less often associated with bloody diarrhea. shigella species were rarely isolated f ... | 1991 | 2047642 |
| digalactosyl-containing glycolipids as cell surface receptors for shiga toxin of shigella dysenteriae 1 and related cytotoxins of escherichia coli. | purified glycolipids containing galactose-alpha(1-4)galactose bind with shiga toxin of shigella dysenteriae 1 and shiga-like toxins of escherichia coli with high specificity in both thin-layer chromatograms and glycolipid-coated microtiter plates. these glycolipids appear to be the natural cell surface receptors for this class of bacterial toxins since artificial glycoconjugates block cytotoxicity as well as binding of 125i-labeled toxin. cell lines lacking these glycolipids are refractory to to ... | 1991 | 2047653 |
| [the drug resistance and dna plasmid profiles of shigella dysenteriae 1 in the ussr and abroad]. | the medicinal resistance and plasmid profiles of 62 s. dysenteriae strains 1, isolated in the ussr in 1986-1988 from soviet and foreign citizens (from afghanistan, vietnam) and 8 strains obtained from india in 1987 were studied. pronounced similarity between the phenotypes of medicinal, including conjugative, resistance in the strains of soviet and foreign origin was established. in the soviet s. dysenteriae strains 1 the presence of two main types of plasmid dna profiles (140, 6, 4, 2 md and 14 ... | 1990 | 2075761 |
| [the characteristics of the biological properties of shigella dysenteriae 1 circulating in the ussr and india: its biochemical activity and agglutinability]. | the properties of 71 s. dysenteriae 1 strains isolated from patients in the ussr and india in 1986-1988 were studied. the cultures possessed typical biochemical and serological properties. as revealed in this investigation, high fastidiousness of this infective agent to the quality of synthetic nutrient could become the cause of false negative reactions in different substrates used for the identification of enterobacteria, thus leading to diagnostic mistakes. the variability of the biochemical a ... | 1990 | 2097846 |
| construction and evaluation of live attenuated vaccine strains of shigella flexneri and shigella dysenteriae 1. | shigellosis is an invasive disease of the human colon which is particularly prevalent among children of the developing world. no proper vaccine is available to protect against this enteric disease. it is currently accepted that only live strains with attenuated virulence administered orally may elicit protective immunity at the level of the colonic mucosa, which is the exclusive site of multiplication of causative microorganisms such as shigella flexneri and shigella dysenteriae 1. we have const ... | 1990 | 2101481 |
| immunodetection of lipopolysaccharide in macrophages during the processing of non invasive shigella dysenteriae. | the location of lipopolysaccharide (lps) was studied by immunofluorescence and immunoelectron microscopy in macrophages infected with a non-invasive shigella dysenteriae 1 strain. bacterial degradation began only 3 h after the end of infection. the first visible sign of degradation was detected by immunogold labelling at the level of lps which detached from the bacterial surface and was transferred to the perinuclear lysosomes. after a few hours, it was found in small vesicles spread over the wh ... | 1990 | 2129020 |
| trimethoprim resistance gene in shigella dysenteriae 1 isolates obtained from widely scattered locations of asia. | trimethoprim-resistance genes of shigella dysenteriae 1 strains, isolated from a different location of six different countries of asia over a 5-year period were characterized by using three different dihydrofolate reductase (dhfr) gene probes. the trimethoprim-resistant (tmpr) strains hybridized only with the type i dhfr gene probe by colony hybridization. none of the strains hybridized with types ii and iii dhfr gene probes. southern blot experiments using plasmid dna extracted from these resis ... | 1990 | 2182327 |
| epidemiology of shigellosis in teknaf, a coastal area of bangladesh: a 10-year survey. | the epidemiological data on shigellosis in teknaf, a coastal area of bangladesh, were reviewed for a 10-year period (1975-84). certain similarities and differences were observed in the epidemiology of the disease in teknaf when compared with urban dhaka and rural matlab. similarities included: round-the-year infection with two peaks, one in the monsoon period and the other in the winter period; high male to female attendance ratio at the treatment centre; the predominance of infection in the und ... | 1990 | 2200700 |
| [a case of shigellosis due to shigella dysenteriae 1 which was thought to be infected in domestic area]. | a 43-year-old man was admitted to our hospital because of bloody diarrhea and abdominal pain on january 10, 1989. on laboratory examination s. dysenteriae 1 was isolated from his stool, therefore he was diagnosed as shigellosis. after the administration of ofloxacin was started, s. dysenteriae 1 was immediately eradicated. but his diarrhea persisted until the 19th day from the onset of the illness and his abdominal pain persisted until the 21st day. he had never been overseas and he had never ea ... | 1990 | 2205674 |
| immunolabelling of shiga toxin in macrophages infected with shigella dysenteriae 1. | immunolabelling of shiga toxin in macrophages infected with a non-invasive shigella dysenteriae 1 isolate showed that bacteria remained alive for 3 h after ingestion within the phagocytic vacuole and synthesized shiga toxin. the normal process of toxin secretion was, however, impaired by the phagosomal environment and toxin molecules accumulated within the bacterial cytoplasm. | 1990 | 2218059 |
| differentiation of shiga toxin and vero cytotoxin type 1 genes by polymerase chain reaction. | two sets of synthetic oligonucleotide primers were used in a polymerase chain reaction technique to distinguish genes for shiga toxin in shigella dysenteriae 1 and type 1 vero cytotoxin (vt1) in escherichia coli. vt1a and vt1b primers directed at a common 130-base-pair (bp) fragment of the stx and slti genes detected template nucleic acid in both shiga toxin-positive s. dysenteriae 1 and vt1-producing e. coli strains. vt1c and vt1d primers, targeting a 140-bp fragment of the promoter region of t ... | 1990 | 2230244 |
| a method for detecting shiga toxin and shiga-like toxin-i in pure and mixed culture. | shiga toxin and shiga-like toxins (slts, syn. verotoxins) are currently detected by tissue culture assays that are expensive, time-consuming and require specialised facilities and experienced personnel. we have developed a rapid method to detect shiga toxin and slt-i (verotoxin 1) based on their binding to globotriosyl ceramide (gb3). bound toxin was then detected by an enzyme-linked immunosorbent assay (elisa) with monoclonal antibodies. the direct detection of cytotoxins from pure culture plat ... | 1990 | 2391709 |
| 'o'-antigens are essential virulence factors of shigella sonnei and shigella dysenteriae 1. | a novel transposon mutagenesis system has been developed for shigella. we have used it to isolate specific mutants of shigella sonnei and shigella dysenteriae 1 that fail to produce lipopolysaccharide 'o' side chains. the virulence of the mutants was evaluated in the sereny test and in a hela cell invasion assay. all ho'-minus mutants failed to provoke a positive sereny reaction but retained the ability to invade hela cells. this demonstrates that 'o' side chains are virulence factors of s. sonn ... | 1985 | 2413650 |
| inactivation by polymyxin b of the endotoxin-mediated interferon production in the rabbit. | polymyxin b (pb) completely or at least significantly inhibited the capacity of shigella dysenteriae 1 cells and the lipopolysaccharide (lps) and lipid a (la) subunits of several bacterial endotoxins to induce interferon (ifn) in rabbits. animals injected with lps inactivated by pb to the point of not inducing detectable ifn levels did not develop hyporesponsiveness to secondary ifn induction by a homologous inducer. it was concluded that pb inhibits the ifn-inducing capacity of endotoxin and it ... | 1985 | 2413651 |
| the stability of o-antigen plasmid is determined by a chromosomal region of shigella dysenteriae 1. | it is well established that plasmids are involved in the expression of lipopolysaccharide in certain species of shigella. in shigella sonnei, both the biosynthesis of oligosaccharide side chains (o antigen), and cell invasiveness are controlled exclusively by a 120 megadalton (mda) plasmid. in shigella dysenteriae 1, a 10 kilobase (kb) plasmid is required for o-antigen production. shigella dysenteriae 1 strains devoid of this plasmid lose the ability to synthesize o antigen. interestingly, this ... | 1988 | 2454151 |
| purification and characterization of a phage-encoded cytotoxin from an escherichia coli o111 strain associated with hemolytic-uremic syndrome. | cytotoxin production by escherichia coli o111:h-strain hus-2 (hamburg) is associated with a temperate toxin-converting bacteriophage (tcp-111). e. coli laboratory strain c600 transduced and subsequently lysed by the phage produced and liberated large amounts of cytotoxin (ct111) which was purified by sequential chromatography. when compared with published procedures for toxin release from viable cells, lysis of the c600 culture by the phage was most effective. by sds-page ct111 as shiga toxin fr ... | 1988 | 2464885 |
| cloning of the rfb gene region of shigella dysenteriae 1 and construction of an rfb-rfp gene cassette for the development of lipopolysaccharide-based live anti-dysentery vaccines. | recent studies have shown that determinants for the production of o antigen lipopolysaccharide in shigella dysenteriae 1 are distributed over two distinct genetic elements, the chromosome and a 9 kb plasmid designated phw400. in this communication, we describe the cloning of all determinants necessary for s. dysenteriae 1 o antigen production in e. coli k-12 and their combination in a single plasmid. an rp4::minimu r-prime plasmid, r-prime 40, containing the his-rfb (histidine biosynthesis-lipop ... | 1986 | 2469931 |
| genetic and biochemical analysis of shigella dysenteriae 1 o antigen polysaccharide biosynthesis in escherichia coli k-12: 9 kb plasmid of s. dysenteriae 1 determines addition of a galactose residue to the lipopolysaccharide core. | production of the somatic antigen, o-specific polysaccharide of shigella dysenteriae 1 is determined by the chromosomal rfb gene cluster and the rfp gene located on the 9 kb plasmid phw400 carried by this organism. when transferred to escherichia coli k-12, which produces lipopolysaccharide consisting only of core oligosaccharide linked to lipid a, rfp gene-containing plasmids caused modification of the core oligosaccharide leading to the appearance of core molecules with new electrophoretic mob ... | 1986 | 2469932 |
| genetic and biochemical analysis of shigella dysenteriae 1 o antigen polysaccharide biosynthesis in escherichia coli k-12: structure and functions of the rfb gene cluster. | the genetic organization and functions of the shigella dysenteriae 1 rfb gene cluster, which specifies the somatic o antigen in this organism, have been studied in escherichia coli k-12 by insertion and deletion mutagenesis of pss9, a pbr322 hybrid containing the shigella rfb genes. on the basis of the sensitivity/resistance to rough-specific bacteriophage t3 of e. coli k-12 derivatives containing mutant pss9 plasmids, of the banding patterns and immunoreactivity of lps isolated from such deriva ... | 1986 | 2469933 |
| endocytosis from coated pits of shiga toxin: a glycolipid-binding protein from shigella dysenteriae 1. | evidence is presented that endocytosis is involved in the transport to the cytosol of the cytotoxin from shigella dysenteriae 1, shiga toxin, which acts by removal of a single adenine residue in 28-s ribosomal rna. inhibition of endocytosis by atp depletion of the cells prevented toxin uptake. exposure of hela s3 and vero cells to toxin at low extracellular ph, where translocation to the cytosol, but not endocytosis is inhibited, allowed the toxin to accumulate in a compartment where it was prot ... | 1989 | 2564398 |
| causes of death and the histopathologic findings in fatal shigellosis. | thirty-seven children (median age, 2 years) with shigellosis in bangladesh were subjected to postmortem examination to determine causes of death and the spectrum of intestinal histopathology. infecting species were: shigella dysenteriae 1, 7 cases; s. dysenteriae 2, 2 cases; shigella flexneri, 23 cases; shigella boydii, 4 cases; and mixed infection with shigella boydii and shigella sonnei, 1 case. complicating conditions detected before death included malnutrition in 25 cases, pneumonia in 11 ca ... | 1989 | 2594452 |
| quantitation of the rabbit intestinal glycolipid receptor for shiga toxin. further evidence for the developmental regulation of globotriaosylceramide in microvillus membranes. | shiga toxin, produced by shigella dysenteriae 1, causes enterotoxic, cytotoxic, and neurotoxic effects, which may be mediated by a glycolipid receptor, globotriaosylceramide, gb3. to study the relationship of this receptor and toxin effects, globotriaosylceramide was quantitated and further characterized in rabbit small intestinal microvillus membranes at various ages. glycolipids were extracted from rabbit microvillus membranes, purified on unisil columns, and quantitated by high-performance li ... | 1989 | 2663611 |
| congo red-mediated regulation of levels of shigella flexneri 2a membrane proteins. | the ability of shigella spp. to bind congo red from agar medium is generally correlated with their virulence properties. we used a metabolically active culture of shigella flexneri 2a to determine the effect of congo red on its membrane protein profiles. virulent s. flexneri grown in the presence of congo red at 37 degrees c showed increased levels of three proteins with mrs of 43,000, 58,000, and 63,000 (43k, 58k, and 63k proteins) in the sarkosyl-soluble membrane fractions. the observed phenom ... | 1989 | 2663721 |
| production of vero cytotoxin by escherichia coli and shiga toxin by shigella dysenteriae 1 as related to the growth medium and availability of iron. | six strains of escherichia coli producing vero cytotoxin (vtec) and six strains of shigella dysenteriae 1 were examined for the production of extra- and intracellular vero cytotoxin (vt) and shiga toxin respectively, in relation to the growth medium and availability of iron. vtec secreted less extracellular vt1 or vt2 when grown in trypticase soy broth (tsb) containing the iron chelator desferal, as compared to bacteria cultured in iron replete tsb. growth in tsb containing desferal resulted in ... | 1989 | 2692581 |
| [drug resistance of the causative agent of grigo'rev-shiga dysentery (shigella dysenteriae 1)isolated in the ussr]. | forty strains of s. dysenteriae 1 isolated in the ussr within 1986-1988 were tested for their resistance to 11 antibacterial drugs. it was shown that 92.5-97.5 per cent of the isolates were resistant to chloramphenicol (cm) and tetracycline (tc), 22.5 per cent to streptomycin (sm), 17.5 per cent to nalidixic acid (nal) and 10 per cent to ampicillin (ap) and polymyxin (pm). resistance to cm tc (51.4 per cent) and cm tc nal (13.5 per cent) represented the predominating phenotype. 35 per cent of th ... | 1989 | 2694989 |
| relationship between multiple drug-resistance & enterotoxin production by shigella species. | culture filtrates prepared with strains of shigella dysenteriae 1 and those of sh. flexneri and sh. sonnei, collected from different geographical locations in india caused accumulation of fluid in rabbit gut loops, indicating their capability to produce shiga and shiga-like toxins respectively. sh. boydii strains were noted for the first time to produce shiga-like toxins. the failure of production of fluid accumulation in rabbit gut by shigella strains that lacked the r-markers of the antibiotic ... | 1989 | 2737704 |
| dna probes for shiga-like toxins i and ii and for toxin-converting bacteriophages. | a set of dna probes has been developed to study the genes for shiga-like toxins (slt) and the bacteriophage from which these toxin genes were isolated. under stringent conditions of hybridization (80 to 90% homology), these probes detect strains containing (i) slt i-related genes, (ii) slt ii-related genes, (iii) phage sequences from the slt i-converting phage h19a/933j, and (iv) phage sequences from the slt ii-converting phage 933w. strain characterization by hybridization with the toxin gene p ... | 1988 | 2842369 |
| cloning and expression of the genes specifying shiga-like toxin production in escherichia coli h19. | some strains of escherichia coli produce a protein which is cytotoxic for vero cell and hela cell monolayers. this toxin is very similar to the toxin of shigella dysenteriae 1 and has been named verotoxin or e. coli shiga-like toxin. it has been shown that toxin conversion is due to a group of bacteriophages, one of which has been designated h-19b. in this study we report hybridization experiments showing that part of the h-19b genome is homologous to phage lambda. we have cloned a 1.7-kilobase ... | 1986 | 3009393 |
| studies on enterotoxin of shigella dysenteriae type 1. ii. systemic effects in rabbits of shigella dysenteriae 1 enterotoxin. | the enterotoxin of shigella dysenteriae type 1 is an acid and heat-labile protein. it induces a gut dilatory response and increases the levels of blood glucose, serum alkaline phosphatase and serum acid phosphatase in rabbits. | 1986 | 3019069 |
| direct cytotoxic action of shiga toxin on human vascular endothelial cells. | to help explain a role of the shiga toxin family in hemorrhagic colitis and hemolytic-uremic syndrome in humans, it has been hypothesized that these toxins cause direct damage to the vascular endothelium. we now report that shiga toxin purified from shigella dysenteriae 1 does indeed have a direct cytotoxic effect on vascular endothelial cells in cultures. human umbilical vein endothelial cells (huvec) in confluent monolayers were reduced 50% by 10(-8) m shiga toxin after a lag period of 48 to 9 ... | 1988 | 3044997 |
| the primary structure of the operons coding for shigella dysenteriae toxin and temperature phage h30 shiga-like toxin. | nucleotide(nt) sequences were determined for the toxin (sht) operon present in the chromosome of shigella dysenteriae 1 and for the shiga-like toxin (slt) operon found in the lambdoid phage h30 genome. the coding sequences of the sht and slt genes differ in 4 nt with 1 nt change responsible for an amino acid replacement. the deduced amino acid sequence in the a chain of the toxins is highly homologous to that of the a chain of ricin, a plant toxin. sht-coding mrnas were detected by mapping the 5 ... | 1988 | 3049254 |
| dna probes to identify shiga-like toxin i- and ii-producing enteric bacterial pathogens isolated from patients with diarrhea in thailand. | when shigella species, escherichia coli, and five other bacterial enteric pathogens isolated from children with diarrhea in thailand were tested for hybridization under stringent conditions with probes for shiga-like toxins i and ii, only 30 shigella dysenteriae 1 hybridized with the shiga-like toxin i probe. | 1988 | 3049664 |
| development of dna probes for cytotoxin and enterotoxin genes in enteric bacteria. | dna probes to identify the genes encoding toxins in enteric bacteria have been developed. use of these probes reduces the number of animals required for toxicity testing, as suspect bacteria can be directly tested for the presence of toxin. we have augmented the gene probes available by developing probes against the escherichia coli enterotoxin ltii and shiga toxin from shigella dysenteriae 1. the ltii gene from e. coli 357900 was identified and characterised and a suitable internal probe was ob ... | 1988 | 3053231 |
| role of shiga toxin in the pathogenesis of bacillary dysentery, studied by using a tox- mutant of shigella dysenteriae 1. | a tox- mutant of shigella dysenteriae 1, sc501, was genetically engineered by cloning the shiga toxin operon, inserting a cassette into the a subunit gene, and exchanging this in vitro-mutagenized sequence with the wild-type gene. sc501 produced a low amount of residual cytotoxicity which was not neutralized by a rabbit immune serum directed against shiga toxin. invasion of cultured cells demonstrated that shiga toxin had no effect on the rate of intracellular growth of bacteria or on the rapid ... | 1988 | 3053452 |
| [the world-wide pandemic and drug resistance of the causative agent of grigor'ev-shiga dysentery]. | one of the factors facilitating the global pandemic of grigor'ev-shiga dysentery is considered in detail. all shigella dysenteriae 1 strains, irrespective of the geographical zone of their spread, showed medicinal resistance. as pandemic developed, the spectrum of medicinal resistance constantly increased in all hyperendemic foci. the presence of pronounced relationships between the strains circulating in each of three hyperendemic foci and the strains circulating in different hyperendemic foci ... | 1988 | 3064514 |
| identity of molecular structure of shiga-like toxin i (vt1) from escherichia coli o157:h7 with that of shiga toxin. | the primary structures of the a and b subunits of shiga toxin and of shiga-like toxin i (vt1), isolated from the culture supernatants of shigella dysenteriae 1 and escherichia coli o157:h7, respectively, were analyzed by edman degradation of intact proteins and peptides in their digests with trypsin or achromobacter protease i and also by fast atom bombardment mass spectrometry of the digests. the results indicated that the a and b subunits of shiga toxin and shiga-like toxin i have the same pri ... | 1988 | 3070268 |
| characterization of purified shiga toxin from shigella dysenteriae 1. | shiga toxin was purified from the culture supernatant of shigella dysenteriae 1 by ammonium sulfate fractionation, deae-cellulose column chromatography and repeated chromatofocusing column chromatography. about 1.6 mg of purified shiga toxin was obtained from 15 liters of culture with a yield of about 27%. the molecular weight of purified shiga toxin was estimated to be 62,000. the toxin consisted of a and b subunits with molecular weights of about 30,000 and 5,000-6,000, respectively. the isoel ... | 1986 | 3100915 |
| effects of iron and temperature on shiga-like toxin i production by escherichia coli. | iron is known to depress shiga toxin production by shigella dysenteriae 1, and temperature has been shown to regulate several genes required for shigella invasiveness. in this study, the influence of iron and temperature on regulation of a highly related toxin, shiga-like toxin i (slt-i) of enterohemorrhagic escherichia coli, was examined in strains lysogenic for the toxin-converting coliphage 933j and in strains carrying the cloned slt-i genes on a high-copy-number plasmid vector. for compariso ... | 1988 | 3121508 |
| purification and some properties of shiga-like toxin from escherichia coli o157:h7 that is immunologically identical to shiga toxin. | a cytotoxin to vero cells (shiga-like toxin), which was neutralized by antibody against purified shiga toxin produced by shigella dysenteriae 1, was purified from escherichia coli o157:h7, isolated from a patient with hemorrhagic colitis. the purification procedure consisted of ammonium sulfate fractionation, deae-cellulose column chromatography, chromatofocusing column chromatography and high performance liquid chromatography. about 200 micrograms of purified shiga-like toxin was obtained from ... | 1987 | 3148810 |
| control of diarrhoeal diseases. | during its early years, who was primarily concerned with epidemic control, standardization and quality control of vaccines, and administration of the international sanitary regulations. among the acute enteric infections, cholera received the greatest attention because of its propensity for rapid epidemic spread. when the seventh pandemic of cholera began in 1961, who responded with a greatly expanded programme of activities which included cooperation with countries in training and control effor ... | 1988 | 3176516 |
| site of action of a vero toxin (vt2) from escherichia coli o157:h7 and of shiga toxin on eukaryotic ribosomes. rna n-glycosidase activity of the toxins. | the site of action of a vero toxin (vt2 or shiga-like toxin ii) from enterohemorrhagic escherichia coli and shiga toxin from shigella dysenteriae 1 on eukaryotic ribosomes was studied. treatment of eukaryotic ribosomes with either toxin caused the release of a fragment of 400 nucleotides from 28s ribosomal rna when the isolated ribosomal rna was treated with aniline. release of this fragment with aniline treatment was accompanied by inhibition of protein synthesis and of elongation-factor-1-depe ... | 1988 | 3276522 |
| nucleotide sequence of the shiga-like toxin genes of escherichia coli. | we have determined the nucleotide sequence of the slta and sltb genes that encode the shiga-like toxin (slt) produced by escherichia coli phage h19b. the amino acid composition of the a and b subunits of slt is very similar to that previously established for shiga toxin from shigella dysenteriae 1, and the deduced amino acid sequence of the b subunit of slt is identical with that reported for the b subunit of shiga toxin. the genes for the a and b subunits of slt apparently constitute an operon, ... | 1987 | 3299365 |
| iron regulation of shiga-like toxin expression in escherichia coli is mediated by the fur locus. | shiga-like toxin is an iron-regulated cytotoxin quite similar to shiga toxin from shigella dysenteriae 1. the structural genes for shiga-like toxin in escherichia coli (slta and sltb) appear to be transcribed as an operon from a promoter upstream of slta. we used a gene fusion between the promoter and proximal portion of slta with the gene for bacterial alkaline phosphatase to assess the regulation of toxin expression. growth in low-iron conditions resulted in a 13- to 16-fold increase in alkali ... | 1987 | 3308853 |
| xylose lysine desoxycholate agar for recovering shigella dysenteriae 1 and shigella flexneri from faeces. | | 1987 | 3330107 |
| shiga toxin from shigella dysenteriae 1 inhibits protein synthesis in reticulocyte lysates by inactivation of aminoacyl-trna binding. | inhibition of the peptide elongation cycle of eukaryotic protein synthesis by shiga toxin from shigella dysenteriae 1 was examined in toxin-treated reticulocyte lysate mixtures. peptidyl transferase activity of toxin-treated ribosomes was measured by following the decrease in peptidyl-trna concentrations when puromycin was added after incubation with toxin. concentrations of [3h]leucine-labeled peptidyl-trna were measured by extraction with cetyltrimethylammonium bromide. the data suggest that s ... | 1986 | 3334156 |
| colonic perforation in shigella dysenteriae 1 infection. | | 1986 | 3511451 |
| production of shiga toxin and other cytotoxins by serogroups of shigella. | we measured the cytotoxic activity of 119 strains of shigella by using a quantitative [3h]thymidine-labeled hela cell assay. we assayed 13 strains of shigella dysenteriae 1; 18 strains of s. dysenteriae types 2 and 3; and 88 strains of shigella sonnei, shigella flexneri, and shigella boydii. strains of s. dysenteriae 1 demonstrated high levels of cytotoxicity (geometric mean, 10(5.04) cd50/mg of protein; range, 10(3.95)-10(6.10). cytotoxic activities of the non-type 1 strains of s. dysenteriae a ... | 1986 | 3537154 |
| ionic requirements for entry of shiga toxin from shigella dysenteriae 1 into cells. | the ionic requirements for entry of shiga toxin into cells were examined by measuring inhibition of protein synthesis after short-term incubations with toxin. the sensitivity of vero cells and hela cells to shiga toxin was strongly dependent on the divalent cation present. vero cells were most sensitive in the presence of cacl2 and srcl2, whereas hela cells were equally sensitive in the presence of mgcl2, srcl2, and cacl2. both cell lines were protected by bacl2, cocl2, and mncl2. inhibitors of ... | 1987 | 3542829 |
| cytotoxicity of shiga toxin for primary cultures of human colonic and ileal epithelial cells. | shiga toxin purified from shigella dysenteriae 1 was cytotoxic to cultured epithelial cells from human colon and ileum. the cytotoxicity, which affected only about 50% of treated cells, was neutralized by rabbit antiserum monospecific for shiga toxin and mediated by protein synthesis inhibition. | 1987 | 3570477 |
| clinical and biochemical significance of toxin production by aeromonas hydrophila. | production of cytotoxin and enterotoxin by aeromonas strains obtained from stools of 50 children in mexico and texas and from blood of 9 children with sepsis was determined. results were correlated with clinical features of infected children as well as with biochemical traits of aeromonas strains. cytotoxin was produced by 40 of 42 aeromonas strains (95%) isolated from stools of children with diarrhea, by all 8 isolates from stools of well children, and by all 9 isolates from children with sepsi ... | 1987 | 3584426 |
| the mode of action of shiga toxin on peptide elongation of eukaryotic protein synthesis. | the effect of shiga toxin, from shigella dysenteriae 1, on the component reactions of peptide elongation were investigated. enzymic binding of [3h]phenylalanine-trna to reticulocyte ribosomes was inhibited by 50% at 7 nm toxin. elongation factor 1 (eef-1)-dependent gtpase activity was also inhibited. both reactions were not restored by addition of excess eef-1 protein. in contrast, toxin concentrations of 200 nm were required to inhibit by 50% the elongation factor 2 (eef-2)-dependent translocat ... | 1987 | 3663122 |
| shigella toxin and the pathogenesis of shigellosis. | shigella dysenteriae 1 produces a periplasmic protein with multiple toxic effects in vivo and in vitro. these include neurotoxicity, cytotoxicity and enterotoxicity, as well as the ability to inhibit cell-free protein synthesis. the purified toxin is a protein of relative molecular mass (mr) 64 000. it is composed of one catalytically active a subunit (mr = 32 000) that inhibits protein synthesis, and a complex of five b monomers (mr approximately 6500 each). studies using subunit-specific antib ... | 1985 | 3847336 |
| plasmid characterization of drug-resistant shigella dysenteriae 1 from an epidemic in central africa. | a widespread epidemic of severe dysentery in zaire and neighbouring central african countries was caused by a multiply drug-resistant strain of shigella dysenteriae 1. early isolations were resistant to ampicillin, chloramphenicol, streptomycin, sulphonamides and tetracyclines (r-type = acssut). later in the epidemic strains resistant to trimethoprim (tm) became prevalent and a few strains resistant to kanamycin (k) or nalidixic acid were also isolated. all resistances except nalidixic acid were ... | 1985 | 3886782 |
| shigellosis due to shigella dysenteriae. 1. relative importance of mucosal invasion versus toxin production in pathogenesis. | | 1972 | 4197755 |
| [transfer of resistance to antibiotics and sulfonamides from shigella dysenteriae 1 (shiga bacillus) to escherichia coli k 12]. | | 1974 | 4212868 |
| the pathogenesis of shigella diarrhea. i. enterotoxin production by shigella dysenteriae i. | a strain of shigella dysenteriae 1, freshly isolated from a patient with dysentery in guatemala in august 1969, was found to elaborate an enterotoxin into the liquid of broth cultures. partial purification of the enterotoxin by ultrafiltration on graded polymeric membranes and sephadex gel filtration (pharmacia fine chemicals, inc., piscataway, n. j.) suggested an approximate molecular weight of 55,000-60,000. the partially purified toxin was heat-labile, pronase sensitive, and activated by alka ... | 1972 | 4560429 |
| laboratory transmission of enterobacteriaceae by the oriental cockroach, blatta orientalis. | methods of maintaining and feeding and of infecting cockroaches with pathogenic organisms were investigated.cockroaches fed on known concentrations of escherichia coli o119, esch. coli o1, alkalescens dispar o group 2 and shigella dysenteriae 1 (shiga's bacillus) were maintained in petri dishes. the effect of various diets on the survival of these organisms within the hind-gut and faeces was observed. with a ;normal' diet of gruel esch. coli o119 was isolated for up to 20 days, esch. coli o1 for ... | 1973 | 4571613 |
| r factors in strains of salmonella typhi and shigella dysenteriae 1 isolated during epidemics in mexico: classification by compatibility. | all 17 salmonella typhi strains tested from the epidemic in mexico carried r factors of compatibility group h, conferring resistance to chloramphenicol, streptomycin, tetracycline, and sulfonamides. some s. typhi strains carried, in addition, non-conjugative, ampicillin resistance plasmids and r factors of the i or a-c complex. all 20 shigella dysenteriae 1 strains tested of epidemic origin carried o-group r factors. ampicillin resistance in s. dysenteriae 1 was not proved to be plasmid borne. r ... | 1974 | 4599123 |
| pathogenesis of salmonellosis. studies of fluid secretion, mucosal invasion, and morphologic reaction in the rabbit ileum. | strains of salmonella typhimurium were studied in the ligated rabbit ileal loop model to gain insight into the mechanisms whereby bacteria which invade the gastrointestinal mucosa evoke fluid exsorption. the organisms employed differed in various biologic attributes including the ability to invade the ileal epithelium, multiply within the mucosa, elicit an acute inflammatory reaction, and disseminate across the intestinal wall. some strains provoked small intestinal fluid exsorption although the ... | 1973 | 4630603 |
| pathogenesis of shigella dysenteriae 1 (shiga) dysentery. | | 1973 | 4631877 |
| relationship of age and serum immunoglobulins to antoantibodies against brain constituents in primates. ii. response of erythrocebus patas to shigella dysenteriae 1 exotoxin. | | 1972 | 4633135 |
| escherichia coli o157:h7 strains associated with haemorrhagic colitis in the united states produce a shigella dysenteriae 1 (shiga) like cytotoxin. | | 1983 | 6132054 |
| purification of shigella dysenteriae 1 (shiga)-like toxin from escherichia coli o157:h7 strain associated with haemorrhagic colitis. | | 1983 | 6136724 |
| environmental and human isolates of vibrio cholerae and vibrio parahaemolyticus produce a shigella dysenteriae 1 (shiga)-like cytotoxin. | some strains of vibrio parahaemolyticus, vibrio cholerae, and non-o1 v cholerae produce a bacterial-cell-associated, heat-stable material that is cytotoxic for hela cells. cytotoxicity is completely neutralised by antibody to purified shigella dysenteriae 1 (shiga) toxin but not by antibody to purified cholera toxin. | 1984 | 6140426 |
| inhibition of protein synthesis in intact hela cells by shigella dysenteriae 1 toxin. | shiga toxin purified to near homogeneity from cell lysates of shigella dysenteriae 1 inhibited protein and deoxyribonucle acid syntheses in intact hela cells. inhibition was dependent on toxin concentration and time of incubation. a minimal latent period of 30 min was observed with saturating doses of toxin. ribonucleic acid synthesis, uptake of alpha-aminoisobutyric acid, and maintenance of intracellular k+ concentrations were not affected until well after maximal inhibition of protein and deox ... | 1980 | 6156915 |
| shigella dysenteriae 1 cytotoxin: periplasmic protein releasable by polymyxin b and osmotic shock. | treatment of shigella dysenteriae 1 either with the antibiotic polymyxin b or by osmotic shock resulted in the release of 80 to 90% of the cytotoxin activity of the organism. under the conditions employed, the release of toxin activity was accompanied by the appearance of a periplasmic enzyme, 5'-nucleotidase. there was no significant release of cytoplasmic contents, assessed by measurement of glucose-6-phosphate dehydrogenase activity. the release of cytotoxin and 5'-nucleotidase by polymyxin b ... | 1983 | 6295958 |
| release of shiga toxin from shigella dysenteriae 1 by polymyxin b. | release of shiga toxin from shigella dysenteriae 1 was found to occur after exposure to polymyxin b. the amount of toxin released was dependent on both the polymyxin concentration and time of incubation. an immunoblot characterization of the shiga toxin released by polymyxin treatment demonstrated that it is electrophoretically similar to purified shiga toxin and to shiga toxin present in crude bacterial sonicates of s. dysenteriae 1 cells. | 1983 | 6299964 |
| purification and characterization of a shigella dysenteriae 1-like toxin produced by escherichia coli. | a toxin from an enteropathogenic strain of escherichia coli (e. coli h30) was purified to apparent homogeneity from cell lysates. the steps used to isolate the e. coli h30 toxin included french pressure-cell disruption of bacteria grown in iron-depleted media. affi-gel blue chromatography, chromatofocusing, and anti-shiga toxin affinity chromatography. the mobilities of the subunits of radioiodinated e. coli h30 toxin and shiga toxin observed after the two toxins were subjected to sodium dodecyl ... | 1983 | 6341244 |
| isolation and characterization of monoclonal antibodies to shiga toxin. | hybridoma cell lines which produce monoclonal antibodies to shiga toxin from shigella dysenteriae 1 were prepared. the monoclonal antibodies were all of the immunoglobulin g1 isotype and differed in their ability to neutralize cytotoxicity and to bind to shiga toxin in a solid-phase radioimmunoassay. when used for immunoblot analysis, these antibodies were able to identify specifically both nicked and unnicked shiga toxin in crude lysates of s. dysenteriae. | 1983 | 6345399 |
| temperature-dependent expression of virulence genes in shigella species. | the pathogenicity of shigella spp. involves the ability of the bacteria to penetrate and replicate within the epithelial cells of the large intestine. model systems for examining the virulence of shigellae employ henle intestinal epithelial cells in tissue culture and an in vivo assay for virulence in guinea pig eyes (sereny test). using these systems, we studied the genetic and physiological bases for the ability of shigellae to invade epithelial cells. we found that expression of virulence in ... | 1984 | 6360895 |
| a small plasmid in shigella dysenteriae 1 specifies one or more functions essential for o antigen production and bacterial virulence. | the role of plasmids in the virulence of shigella dysenteriae 1 w30864, which contains at least five species, was investigated. by means of a standard plasmid-curing procedure, that is, bacterial cultivation at an elevated temperature, five virulence-deficient derivatives were obtained. one of these lacked a small, 6-megadalton plasmid, designated phw400, exhibited reduced invasiveness for hela cells, and failed to produce the somatic antigen. transposon tagging of the phw400 plasmid to produce ... | 1984 | 6360905 |
| small virulence plasmid of shigella dysenteriae 1 strain w30864 encodes a 41,000-dalton protein involved in formation of specific lipopolysaccharide side chains of serotype 1 isolates. | a 6-megadalton plasmid, phw400, of shigella dysenteriae 1 strain w30864 was previously found to specify one or more functions for o-antigen production and bacterial virulence (h. watanabe and k. n. timmis, infect. immun. 43:391-396, 1984). the region of phw401, a tn801-tagged derivative of phw400, responsible for o-antigen production has been localized by gene cloning and tn5 transposon mutagenesis. analysis of lipopolysaccharide isolated from s. dysenteriae 1 bacteria carrying mutant plasmids r ... | 1984 | 6384048 |