Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The monoclonal antibodies to porin, an outer membrane protein isolated from Salmonella typhimurium and sandwich enzyme linked immunosorbent assay (ELISA) has made possible the detection of porin from sera of S. typhimurium-infected mice. The specificity of the monoclonal antibodies was ascertained based on their cross-reactivity with porins isolated from S. typhi, Shigella flexneri and Escherichia coli and lipopolysaccharide (LPS) of S. typhimurium and E. coli. Serum samples were found to be positive for porin as early as 3 days after intravenous and 5 days after oral infection. In addition, a positive correlation was observed between the bacterial load and the concentration of porin detected in the sera. On the other hand, analysis of sera for anti-porin antibody showed diametrically opposite time kinetics with antigenaemia. These results indicate that porin accumulates in the serum of infected mice much earlier than the appearance of antibodies to porin. Thus detection of porin holds promise for early diagnosis of typhoid.
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PMID:Detection of porin antigen in serum for early diagnosis of mouse infections with Salmonella typhimurium. 131 58

The ability of Shigella flexneri to interact with lactoferrin (Lf) was examined with a 125I-labeled protein-binding assay. The percent binding of human lactoferrin (HLf) and bovine lactoferrin (BLf) to 45 S. flexneri strains was 19 +/- 3 and 21 +/- 3 (mean +/- standard error of the mean), respectively. 125I-labeled HLf and BLf binding to strain M90T reached an equilibrium within 2 h. Unlabeled HLf and BLf displaced the 125I-HLf-bacteria interaction in a dose-dependent manner. The Lf-bacterium complex was uncoupled by KSCN or urea, but not by NaCl. The interaction was specific, and approximately 4,800 HLf binding sites (affinity constant [Ka], 690 nM) or approximately 5,700 BLf binding sites (Ka, 104 nM) per cell were estimated in strain M90T by a Scatchard plot analysis. The native cell envelope (CE) and outer membrane (OM) did not reveal Lf-binding components in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. However, after being boiled, the CE and OM preparations showed three distinct horseradish peroxidase-Lf reactive bands of about 39, 22, and 16 kDa. The 39-kDa component was also reactive to a monoclonal antibody specific for porin (PoI) proteins of members of the family Enterobacteriaceae. The Lf-binding protein pattern was similar with BLf or HLf, for Crb+ and Crb- strains. The protein-Lf complex was dissociable by KSCN or urea and was stable after treatment with NaCl. Variation (loss) in the O chain of lipopolysaccharide (LPS) markedly enhanced the Lf-binding capacity in the isogenic rough strain SFL1070-15 compared with its smooth parent strain, SFL1070. These data establish that Lf binds to specific components in the bacterial OM; the heat-modifiable, anti-PoI-reactive, and LPS-associated properties suggested that the Lf-binding proteins are porins in S. flexneri.
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PMID:Lactoferrin-binding proteins in Shigella flexneri. 131 3

O-specific-polysaccharide and core oligosaccharide were isolated from Citrobacter strain PCM 1487 lipopolysaccharide and purified. The polysaccharide was selectively devoid of 4-deoxy-D-arabinohexose residues. Covalent conjugates of the modified O-specific polysaccharide and of the core oligosaccharide with tetanus toxoid were prepared. Immunochemical characterization of these conjugates proved that they are strong immunogens. Using monospecific rabbit antisera raised against the conjugates, the antigenic relationships between lipopolysaccharides of various strains of Citrobacter, Shigella sonnei, and Shigella flexneri were studied by quantitative microprecipitin and quantitative microprecipitin inhibition and immunoblotting tests.
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PMID:Immunochemical characterization of Citrobacter strain PCM 1487 O-specific polysaccharide- and core oligosaccharide-protein conjugates. 137 31

The construction and characterization of EcSf2a-2, an aroD-deleted Escherichia coli-Shigella hybrid vaccine carrying chromosomal and plasmid genes from Shigella flexneri and expressing S. flexneri 2a somatic antigen in association with E. coli K12 core are described. Expression of hybrid lipopolysaccharide and deletion of aroD resulted in the attenuation of phenotypic characteristics associated with pathogenicity. The addition of an aroD deletion results in a requirement for an aromatic precursor of para-aminobenzoic acid (PABA), an essential bacterial metabolite not present in mammalian tissues. The biosynthesis of hybrid somatic antigen prevents expression of a Sereny-positive reaction by invasive bacteria capable of expressing a plaque-positive phenotype. A functional kcpA gene is required for expression of the plaque-positive phenotype. The presence of an aroD deletion does not interfere with expression of an invasive phenotype; however, in bacteria containing a functional kcpA gene, replication and spread by invading bacteria are limited, preventing development of the plaque-positive phenotype.
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PMID:Genotypic and phenotypic characterization of an aroD deletion-attenuated Escherichia coli K12-Shigella flexneri hybrid vaccine expressing S. flexneri 2a somatic antigen. 144 32

We conducted a prospective, community-based study of healthy breast-fed Mexican infants to determine the protective effects of anti-Shigella secretory IgA antibodies in milk. Milk samples were collected monthly, and stool culture specimens were obtained weekly and at the time of episodes of diarrhea. Nineteen breast-fed infants were found to have Shigella flexneri, Shigella boydii, or Shigella sonnei in stool samples. Ages of the 10 infants with symptomatic infection and the nine with asymptomatic infection did not differ significantly. Milk samples collected up to 12 weeks before infection were evaluated by enzyme-linked immunosorbent assay for secretory IgA antibodies against lipopolysaccharides of S. flexneri, S. boydii serotype 2, S. sonnei, and virulence plasmid-associated antigens. The geometric mean titers of anti-Shigella antibodies to virulence plasmid-associated antigens in milk received before infection were eightfold higher in infants who remained well than in those in whom diarrhea developed. The significance of milk secretory IgA directed against lipopolysaccharide was less clear. We conclude that human milk protects infants against symptomatic shigella infection when it contains high concentrations of secretory IgA against virulence plasmid-associated antigens.
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PMID:Concentration of milk secretory immunoglobulin A against Shigella virulence plasmid-associated antigens as a predictor of symptom status in Shigella-infected breast-fed infants. 144 44

The O-specific polysaccharide chain which represents a new type-antigen in lipopolysaccharide (LPS) of Shigella flexneri 88-893 was investigated. The O-polysaccharide chain was found to be composed of repeating units comprising rhamnose, N-acetylglucosamine and glucose (3:1:2). In the passive hemolysis test, group-6 antiserum of S. flexneri exhibited a high hemolytic titer (50% hemolysis titer: 7,900) against sheep red blood cells (SRBC) sensitized with intact 893 LPS, but virtually no hemolytic activity against SRBC sensitized with alkali-treated 893 LPS. None of the type-specific antisera (I-VI), showed any significant hemolytic titer against SRBC sensitized with either intact or alkali-treated 893 LPS. Thus, 893 LPS contained both the group-6 antigen and a new type-antigen which is distinct from any known type-antigen of S. flexneri.
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PMID:[Chemical and serological study of lipopolysaccharide isolated from Shigella flexneri 88-893 possessing a new type-antigen]. 148 4

The appearance of antigen-specific immunoglobulin A (IgA) antibody-secreting cells (ASCs) following natural infection with Shigella sonnei during a common-source outbreak caused by this organism was evaluated in a modified enzyme-linked immunosorbent assay (ELISPOT). A mean IgA ASC value of 2,131.6/10(6) cells against homologous S. sonnei lipopolysaccharide (LPS) was detected in blood samples obtained from patients with bacteriologically proven S. sonnei shigellosis 5 and 10 days after the onset of disease. In the same blood samples, the level of ASC measured against heterologous antigen (Shigella flexneri serotype 2a LPS) was significantly lower than that of the homologous antigen (mean value, 33.12/10(6) cells). Furthermore, the mean number of activated B cells that secreted anti-S. sonnei LPS antibodies was significantly higher among patients with S. sonnei shigellosis than it was among patients with non-Shigella diarrhea (2.5/10(6) cells; standard error, 1.0) and healthy subjects (5.1/10(6) cells; standard error, 2.3) (P less than 0.05). The anti-LPS IgA ASC activity was easily detected within 5 days of the onset of disease, a point at which the levels of anti-S. sonnei LPS IgG and even IgA antibodies were hardly detectable in serum.
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PMID:Presence of specific immunoglobulin A-secreting cells in peripheral blood after natural infection with Shigella sonnei. 150 May 27

This study examined recognition of heterologous Gram-negative endotoxin by antibodies recognizing common lipopolysaccharide core antigens. Gram-negative endotoxins from 11 heterologous bacterial strains were tested for recognition by antibodies against common lipopolysaccharide core antigens. Serum was harvested from a calf immunized with the Rc mutant, Escherichia coli O111:B4 (J5), and affinity purified against endotoxin derived from an Ra mutant, Salmonella typhimurium, producing an antibody reagent recognizing homologous Gram-negative core antigens present in the Rc mutant vaccinal antigen. This reagent demonstrated reactivity against 11 chemically purified Gram-negative endotoxins. Included were endotoxins derived from 3 smooth E. coli species, 2 Salmonella spp., Shigella flexneri, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, and lipid A. Endotoxin derived from K. pneumoniae had significantly higher ELISA reactivity with core antigen specific antibodies than did endotoxin derived from either E. coli O111:B4 (J5) or P. aeruginosa. These results suggest immunization with R mutant bacterins may have utility in the prevention of Gram-negative mastitis even when whole bacteria react poorly with antibodies recognizing common core antigens.
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PMID:Antigenic homology of endotoxin with a coliform mastitis vaccine strain, Escherichia coli O111:B4 (J5). 150 May 77

Enzyme immunoassays (EIA) were used to estimate titres of class-specific antibodies against purified and chemically defined phenol-water-extracted lipopolysaccharide (LPS) antigens of Salmonella serogroup B (BO), Shigella dysenteriae type I, Plesiomonas shigelloides (the same O-antigen as Shigella sonnei) and Shigella flexneri Y. Titres in colostrum and breast milk of Swedish, Vietnamese and Costa Rican mothers from various socioeconomic conditions were compared. The antibodies were mainly of the IgA isotype. IgM antibodies were also present, but only very low concentrations of IgG were found. In Costa Rican mothers, the IgA antibody titres were significantly higher (P less than 0.05) in women of low and middle socioeconomical conditions than were those in mothers of high socioeconomical level. The low titres in the last group were comparable to those found in Swedish mothers. The IgA antibody titres found in Vietnamese mothers were similar to those of Costa Rican mothers from the low and middle socioeconomic conditions, being highest against S. flexneri Y LPS. The IgM antibody titres were also highest in Vietnamese mothers, immediately followed by the Costa Rican mothers of low socioeconomic conditions. The low IgM titres in the Costa Rican women of high socioeconomic level were comparable to those seen in Swedish mothers. The results suggest that, in Costa Rica and Vietnam, S. flexneri is the most prevalent Shigella sp. causing infection and that Salmonella serogroup B infections are rare in all three countries. The results also show that the antibody repertoire in colostrum and breast milk varies. Furthermore, in addition to the prevalence of a specific micro-organism in a determined geographical area, such differences may be associated mainly with exposure to certain pathogens in particular socioeconomic conditions.
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PMID:Titres of class-specific antibodies against Shigella and Salmonella lipopolysaccharide antigens in colostrum and breast milk of Costa Rican, Swedish and Vietnamese mothers. 152 29

The protective efficacy of oral bovine immunoglobulin concentrates derived from colostrum against challenge with Shigella flexneri was studied in healthy adult volunteers in a randomized, double-blind fashion. Volunteers were given a product consisting of hyperimmune immunoglobulin concentrate with a high titer of anti-S. flexneri 2a lipopolysaccharide (LPS) with sodium bicarbonate or a control preparation with sodium bicarbonate three times a day for seven days. On the third day of treatment, volunteers received a challenge of 10(3) colony-forming units of S. flexneri 2a strain 2457T. None of the volunteers who received the high-titered hyperimmune product became ill, compared with 45% of volunteers who received the placebo (P less than 0.05). The duration of shedding of the challenge organism was decreased, and the active immune responses to S. flexneri LPS were less frequent and of lower magnitude in volunteers given the immunoglobulin concentrate than in those in the control group. High-titered, orally administered bovine immunoglobulin concentrate protects against shigellosis and may be useful in preventing shigellosis among travelers, military personnel, and individuals at risk during a Shigella outbreak.
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PMID:Efficacy of bovine milk immunoglobulin concentrate in preventing illness after Shigella flexneri challenge. 152 40


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