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 short-term kinetics and the effects of different dose regimens and formulations on the humoral immune response induced in human subjects by the live attenuated typhoid vaccine Salmonella typhi Ty21a were examined. Antibody responses in jejunal fluid and serum and by specific antibody production in vitro by peripheral blood lymphocytes to S. typhi lipopolysaccharide were determined. A short vaccination schedule of three doses of 10(11) live organisms over 5 days induced significantly greater intestinal IgA antityphoid antibody responses than did two comparable doses 21 days apart. The humoral immune response was dose dependent with 10(10) and 10(11) live organisms stimulating greater intestinal immune responses than did 10(11) killed organisms. No responses were evident with either 10(9) viable organisms or with an enteric-coated preparation. In the continued development and assessment of oral typhoid vaccines, the effects of different doses and formulations and the timing of sampling on the humoral immune response should be considered.
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PMID:The human humoral immune response to Salmonella typhi Ty21a. 198 18

Although the Widal test is simple, inexpensive and the most widely used for serodiagnosis of typhoid fever, the sensitivity and specificity of the test is sometimes doubtful. In this study, an enzyme-linked immunosorbent assay (ELISA) was developed for the detection of serum IgG and IgM antibodies to protein and lipopolysaccharide (LPS) antigens of Salmonella typhi which was compared with the Widal test in various groups of subjects. In typhoid patients with hemocultures positive for S. typhi (TP group), ELISA positivity was found on 100% for IgG antiprotein, 94.44% for IgG anti-LPS and 88.89% for IgM to both the protein and LPS antigens. In contrast, the Widal test was positive in only 61.11% for anti-O and 83.33% for anti-H antibodies. In healthy control subjects (HC group), only 5% of serum samples were positive for IgG anti-protein and none was positive for IgG anti-LPS or IgM to either the protein or LPS. In contrast, the Widal test was positive in 7.5% of HC group for anti-O and 17.5% for anti-H antibodies. In blood bank donors (BB group), both ELISA and Widal tests were positive in 23-40% of sera. Since the hospital records of BB group were incomplete. It might be possible that some of these subjects had recently been infected with S. typhi. Our data indicate that the standard Widal test was associated with false negative reactions in 16-39% of blood culture positive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Determination of antibody from typhoid patients against lipopolysaccharide and protein antigens of Salmonella typhi. 209 64

The relationship between the IgA antibody response in serum (total and polymeric IgA) and intestinal secretions was examined in volunteers subjected to oral and parenteral typhoid vaccination. After oral vaccination (three doses of 10(11) live Ty21a vaccine given at 48-hr intervals), serum pIgA antibody to typhoid lipopolysaccharide (LPS) was detected in seven of the 14 subjects (46.4 +/- 59 U/100 microliters, mean +/- SD). However, all 14 showed a significant intestinal IgA response (993 +/- 2516 and 9349 +/- 6754 U/mg pre- and post-vaccine; t = 5.25, P = 0.0002). The level of pIgA antibody declined rapidly, whereas intestinal IgA antibody levels remained elevated. Serum pIgA antibody was also found after parenteral immunization (two doses of 5 X 10(8) heat-killed bacteria given 14 days apart to six subjects), but an intestinal IgA antibody response was detected in these individuals only after a subsequent course of the oral vaccine given 1 month after initial parenteral immunization. Changes in serum pIgA antibody followed those of total serum IgA antibody rather than those of intestinal antibody. The results indicate that a serum pIgA response can be induced by an antigenic stimulus delivered either orally or parenterally, whereas an intestinal IgA response is induced only by a local antigen stimulus. The regulation of serum pIgA and intestinal IgA appear to be independent.
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PMID:The serum polymeric IgA antibody response to typhoid vaccination; its relationship to the intestinal IgA response. 230 80

A passive haemagglutination test, using sheep red blood cells sensitised with Salmonella typhi lipopolysaccharide, was compared with the Widal test for the serological diagnosis of typhoid fever in an endemic area. The results obtained on sera from 152 patients with bacteriologically confirmed typhoid and 183 patients who did not have typhoid were analysed in terms of sensitivity, specificity, simplicity, and rapidity of the respective tests. The passive haemagglutination test was found to be more sensitive (80%) than the S typhi O antigen (71%) but marginally less sensitive than the H antigen (82%) of the Widal test. The false positive rate on control sera was 1.2% and 6.6%, respectively, for the Widal O and H antigens, and 1.6% for the passive haemagglutination test. Our findings indicate that the passive haemagglutination test is comparable with the Widal test for the serological diagnosis of typhoid fever in endemic areas, but is more simple, rapid, and economic. The passive haemagglutination test may be a useful alternative to the Widal test for the serological diagnosis of typhoid fever in busy microbiology laboratories in areas in which the disease is endemic.
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PMID:Comparison of passive haemagglutination test with Widal agglutination test for serological diagnosis of typhoid fever in an endemic area. 242 36

Fifteen monoclonal antibodies (MAbs) directed against Salmonella typhi were produced and characterized. The specificities of the antibodies were determined by their binding patterns in an enzyme immunoassay, with a panel of lipopolysaccharides isolated from different bacteria. Seven MAbs reacted with S. typhi, Salmonella enteritidis, and Salmonella dublin (all belonging to serogroup D). One MAb also reacted with Salmonella paratyphi A and S. paratyphi B. Five MAbs reacted with S. typhi, S. enteritidis, S. dublin, and S. paratyphi B. Two MAbs did not bind to any lipopolysaccharide but showed reactivity with bacterial sonic extracts isolated from S. typhi, S. paratyphi A, S. paratyphi B, Escherichia coli, and Shigella sonnei. These antibodies would be helpful in studying the complexity of antigenic determinants expressed by S. typhi and the nature of the antibody response during typhoid and paratyphoid fevers and also in the diagnosis of the disease.
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PMID:Monoclonal antibodies delineate multiple epitopes on the O antigens of Salmonella typhi lipopolysaccharide. 246 68

A panel of 14 monoclonal antibodies with specificity for the O-antigenic polysaccharide chain of the lipopolysaccharide of the cell envelope of Salmonella typhimurium was established. The specificity of each antibody clone was determined against a set of Salmonella saccharide antigens, natural and synthetic, in passive hemagglutination and enzyme immunoassays. The monoclonal antibodies could be classified into at least five different groups: (i) O4 epitope specific, (ii) O4,12 specific, (iii) O4,12(2) specific, (iv) O5 specific, and (v) O12 specific. These specificities correspond to different structural and conformational domains of the polysaccharide chain, and often extend over more than one repeating unit (tetrasaccharide) of the polymer. The passive protection afforded by these antibodies was estimated in an experimental mouse typhoid model using S. typhimurium SH2201 for intraperitoneal challenge. Monoclonal antibodies of the IgG3 isotype were available for four of the epitope groups and were protective in the following order of activity O4 greater than O4,12 greater than O4,12(2) greater than or equal to O12. The difference between O4 and 012 antibodies was greater than 2500 fold in protective activity. Antibodies of the IgM class were highly protective irrespective of being of the O4,12 or O12 epitope specificity. Two IgA antibodies with O5 epitope specificity were not protective. The results show that both isotype and epitope specificity can be of importance for the protective ability of antibodies generated by the host.
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PMID:Role of monoclonal O-antigen antibody epitope specificity and isotype in protection against experimental mouse typhoid. 246 61

The current work was undertaken in order to assess the role of the monoclonal antibodies (Mabs) to lipopolysaccharide (LPS) of Salmonella typhi in the induction of passive protection against the challenge with the bacteria in a mice model. BALB/c mice were immunized with the whole bacteria, mice with high anti-LPS antibody titers were killed, the spleens were removed and splenocytes were fused with the mouse plasmocytoma SP2/0. Two IgM monoclonal antibodies against porins were developed. Each one of these Mabs recognized the polysaccharide region of LPS. Passive immunization with supernatant fluid of mice with one of these monoclonal antibodies did not protect against challenged with 20 LD50 and 100 LD50 of Salmonella typhi. The results suggest that LPS is not valuable immunogen for the induction of a protective status against typhoid fever.
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PMID:[Monoclonal antibodies against the lipopolysaccharide of Salmonella typhi 9,12,VI:d. Analysis of passive protection in a mouse model of typhoid fever]. 248 71

We have evaluated several commercial monoclonal antibodies, specific for human IgG subclasses, for their reactivity in an ELISA test for the characterization of subclasses of IgG anti- Salmonella typhi lipopolysaccharide (LPS) antibodies. Four monoclonals, each specific for a single IgG subclass, were chosen for their good reactivity. In 19 typhoid and non-typhoid serum samples, the sum of the ELISA values obtained with the four subclass-specific monoclonals was highly correlated with the ELISA values obtained with a monoclonal anti-total IgG. Moreover, there was no competition among the various IgG subclasses of anti-LPS antibodies. These data indicate that the subclass distribution of IgG anti-LPS antibodies, calculated on the basis of ELISA values in the subclass-specific assays, is likely to reflect the actual distribution of the different subclasses in whole serum. Different subclass patterns of IgG anti-LPS antibodies were observed in serum samples from 11 patients with typhoid fever, with IgG1 and IgG2 being the most represented subclasses. The ELISA method described here will be useful to elucidate the factors that influence the anti-LPS subclass profile during the humoral immune response to Salmonella typhi.
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PMID:Subclass characterization of IgG anti-S.typhi lipopolysaccharide antibodies with commercial monoclonal antibodies. 249 31

Serum samples from 10 patients with culture positive Salmonella typhi infection, 30 febrile non-typhoidal patients, and 22 healthy subjects were tested for both Salmonella common structural antigen (CSA) and antibody to pathogenic species of Salmonella. Serum, urine and stool specimens from these patients were used to detect Salmonella antigen(s). IgM anti-S. typhi lipopolysaccharide antibody gave the best discrimination between typhoid patients, febrile non-typhoidal cases, and healthy control subjects. The highest IgM titer was recorded in the acute phase of the illness. Antigen detection in serum was highly sensitive (87.5%) and specific (100%), and always occurred early in the acute phase of the illness. Detection of antigen in stool was highly sensitive (87.5%) and specific (96.6%), but it usually was not detected until 3 weeks after the onset of acute illness. Antigen detection in urine was less sensitive and specific compared with assays of stool and blood. The study provides good evidence that ELISA for detection of Salmonella CSA and antibody can aid in the diagnosis and confirmation of infections caused by Salmonella.
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PMID:Enzyme-linked immunosorbent assays (ELISA) for the diagnosis of enteric fever. 268 22

Sera from 339 adult febrile patients in Pakistan were tested for antibodies to Salmonella typhi lipopolysaccharide by indirect immunoglobulin G (IgG) and IgM enzyme-linked immunosorbent assay (ELISA) and IgM capture ELISA. A total of 55 patients had S. typhi cultured from their blood, 20 had S. typhi cultured from their stool, 24 were blood or stool culture positive for S. paratyphi A, 41 were culture negative but clinically diagnosed as having enteric fever, 41 had gastrointestinal or urinary tract infections, 41 were clinically diagnosed as having malaria, 20 were smear-positive patients with malaria, 58 had respiratory infections, and the remaining 39 individuals were placed in a miscellaneous group who did not have Salmonella infection. The sensitivities of the indirect IgG ELISA, indirect IgM ELISA, and IgM capture ELISA determined with specimens obtained from the blood culture-positive patients with typhoid fever (positive controls) were 80, 64, and 62%, respectively. The specificities of the assays determined with sera from the patients with respiratory infections (negative controls) were 95, 95, and 97%, respectively. The percentage of smear-positive patients with malaria who were positive by these assays was lower than that in the negative control group. The percentages of individuals in the other patient categories who were positive by these tests were between those obtained with the positive and negative controls. Of the positive controls, 26 were positive by both IgM assays, 9 were IgM positive only by indirect ELISA, and 8 were IgM positive only by IgM capture ELISA. A total of 70% of the positive control patients who were tested for O agglutinins by the Widal tube agglutination assay were positive; however, 29% of the negative control patients were also positive. The indirect IgG ELISA was the single most effective test for the serodiagnosis of typhoid fever in this population.
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PMID:Indirect immunoglobulin G (IgG) and IgM enzyme-linked immunosorbent assays (ELISAs) and IgM capture ELISA for detection of antibodies to lipopolysaccharide in adult typhoid fever patients in Pakistan. 275 2


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