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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The EDTA and Sonicate antigens used in ELISA for detection of IgG antibodies to Legionella Pneumophila serogroups 1-6 and Tatlock was evaluated. Sensitivity and specificity of EDTA antigens were compared with Sonicate antigens in three groups of subjects. In two serum samples from healthy employees, the Lp1 antibody titers with EDTA and Sonicate antigens were less than or equal to 1:160. Testing seven samples from patients indicated that four samples reacted with titers of 1:1280-2560 to Lp1 with EDTA and Sonicate antigens. But in another three samples, the antibody titers to Lp1 with EDTA antigen were lower 1-3 dilution than Sonicate antigen. One of the lowest titer to EDTA was 1:320 that was interpreted as positive. In all of the seven samples, the antibody titers to Lp4 and Tatlock raised to 1:640-2560 with sonicate antigens and significantly higher than the titers with EDTA antigens (1:320-640). The comparison between the EDTA and Sonicate antigens showed that when the antibody titer with EDTA antigens greater than or equal to 1:320 was regarded as a positive mark the sensitivity of EDTA antigens was similar to Sonicate antigens and the specificity was better than Sonicate antigens. Comparison of EDTA antigen was simple. It is worth to further study.
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PMID:[A study on EDTA antigens for detection of IgG antibodies to Legionella pneumophila]. 139 83

In the process of protein kinase reaction carried out in the mixture consisting of tris-HCl buffer, EDTA, MgCl2, gamma-32P-ATP and the cytoplasmic fraction of rabbit pulmonary cells the phosphorylation of proteins with molecular weights of 150 and 55 kD took place. The addition of L. pneumophila culture fluid to the reaction mixture resulted in the splitting of phosphorylated proteins with the formation of the component having a molecular weight of 45 kD. These disturbances in protein kinase reaction were found to occur due to the involvement of Legionella cytoplasm, a previously characterized protein with a molecular weight of 37 kD, into the process. In this connection, the participation of cytolysin in the pathogenesis of Legionella infection may also be considered from the viewpoint of the effect produced by cytolysin on the regulatory processes affecting the metabolism of target cells.
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PMID:[The splitting of the acceptor proteins of the protein kinase system in eukaryotic cells by Legionella cytolysin]. 195 Feb 77

A monoclonal antibody was used to characterize a serogroup 1 specific Legionella pneumophila Philadelphia strain 1 antigenic determinant. A quantitative fluorometric assay was developed to quantitate the antibody sites (2.7 +/- 0.4 X 10(5)) on Legionella bacteria and to determine the physico-chemical parameters of the antibody-antigen interaction (at 4 degrees C: delta G = -10.9 Kcal X mol-1, delta H = 1.7 Kcal X mol-1, delta S = 45 cal X K-1 X mol-1). The same method was used to study the modification or the removal of the antigen by chemical and enzymatic means (trypsin, papain, lysozyme, acetone, chloroform-methanol and Tris-EDTA); only Tris-EDTA extraction resulted in a significant decrease in antibody binding sites. Inhibition studies of the fluorescein-labelled antibody binding were performed with different sugars of which only L-fucosylamine was inhibitory, and with other monoclonal antibodies to Legionella pneumophila serogroup 1 in order to compare their fine specificity and affinity. The results indicate that the epitope recognized was an immunodominant carbohydrate including an aminodideoxyhexose and carried by the lipopolysaccharide.
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PMID:Partial characterization of a Legionella pneumophila serogroup 1 immunodominant antigenic determinant recognized by a monoclonal antibody. Legionella specific antigenic determinant. 243 83

Several strains of Legionella pneumophila and other species of Legionella with proteolytic activities were compared by assays, including Southern hybridizations and Western immunoblots, to determine their proteolytic, hemolytic, and cytotoxic activities. Only proteases from strains of L. pneumophila were both hemolytic and cytotoxic, and proteolytic activities extracted from other species of Legionella possessed only hemolytic activity. A 4.0-kilobase DNA sequence encoding the 38-kilodalton metalloprotease from L. pneumophila Philadelphia 1 that we showed previously was responsible for the observed hemolytic and cytotoxic phenotypes (F. D. Quinn and L. S. Tompkins, Mol. Microbiol., 3:797-805, 1989) was used in Southern hybridizations to probe chromosomal DNA from several strains of L. pneumophila and other Legionella species. The probe hybridized to the chromosomal DNA of all serogroups of L. pneumophila but not to any strains of L. dumoffii, L. micdadei, L. feeleii, or L. jordanis that we examined. Additionally, Western immunoblots done with rabbit antisera made to the cloned L. pneumophila protease demonstrated cross-reactions among 38-kilodalton proteins from strains of L. pneumophila, but no reactions were observed with proteins from other species of Legionella. Similarly, the cloned protease from L. pneumophila reacted with convalescent-phase sera from patients infected with L. pneumophila, but not with antisera isolated from patients infected with other Legionella species. Thus, despite some similarities among the proteolytic activities of members of the genus Legionella, including proteolytic and hemolytic phenotypes, metal requirements for zinc or iron, sensitivity to EDTA, and temperature and pH optima, we documented distinct genetic, immunological, and cytotoxicity differences among the proteolytic activities produced by Legionella species.
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PMID:Genetic, immunological, and cytotoxic comparisons of Legionella proteolytic activities. 266 84

Serospecific antigens isolated by EDTA extraction from four serogroups of Legionella pneumophila were analyzed for their chemical composition, molecular heterogeneity by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunological properties. The antigens were shown to be lipopolysaccharides and to differ from the lipopolysaccharides of other gram-negative bacteria. The serospecific antigens contained rhamnose, mannose, glucosamine, and two unidentified sugars together with 2-keto-3-deoxyoctonate, phosphate, and fatty acids. The fatty acid composition was predominantly branched-chain acids with smaller amounts of 3-hydroxymyristic acid. The antigens contain periodate-sensitive groups; mannosyl residues were completely cleaved by periodate oxidation. Hydrolysis of the total lipopolysaccharide by acetic acid resulted in the separation of a lipid A-like material that cross-reacted with the antiserum to lipid A from Salmonella minnesota but did not comigrate with it on sodium dodecyl sulfate gels. None of the four antigens contained heptose. All of the antigen preparations showed endotoxicity when tested by the Limulus amebocyte lysate assay. The results of this study indicate that the serogroup-specific antigens of L. pneumophila are lipopolysaccharides containing an unusual lipid A and core structure and different from those of other gram-negative bacteria.
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PMID:Serospecific antigens of Legionella pneumophila. 301 18

Phospholipase C from the Dallas 1E strain of Legionella pneumophila serogroup 5 was purified from buffered yeast extract culture supernate by ion-exchange chromatography followed by fractionation by manganous chloride and ammonium sulphate precipitation steps. Enzyme activity was assayed by hydrolysis of p-nitrophenylphosphorylcholine and confirmed by release of radioactivity from tritiated L-alpha-dipalmitoylphosphatidylcholine labelled in the methyl groups of choline. After SDS-PAGE, the purified preparation yielded a single band upon Coomassie-blue staining. This protein migrated with an apparent Mr of 50,000-54,000. Phospholipase C activity was maximal at pH greater than or equal to 8.4 and was enhanced in the presence of sorbitol and of several nonionic detergents but was eliminated by SDS. EDTA, Cu2+, Fe2+ and Zn2+ inhibited enzyme activity, whereas Ba2+, Ca2+, Co2+, Mg2+ and Mn2+ restored activity to EDTA-treated material. No haemolytic activity was demonstrated with the purified enzyme.
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PMID:A phospholipase C from the Dallas 1E strain of Legionella pneumophila serogroup 5: purification and characterization of conditions for optimal activity with an artificial substrate. 317 47

beta-Lactamase was purified from a strain of Legionella gormanii. The molecular weight of the purified enzyme was 25,000, and its isoelectric point was 10.5. The enzyme hydrolyzed oxyiminocephalosporins, cephamycins, penicillins, and imipenem. The enzyme activity was inhibited by EDTA, Hg2+, and Cu2+, but not by clavulanic acid, sulbactam, or imipenem.
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PMID:Biochemical properties of beta-lactamase produced by Legionella gormanii. 348 20

Legionella pneumophila, the etiologic agent of Legionnaires' disease, is phagocytized in an unusual way and multiplies in human mononuclear phagocytes in a novel phagosome. As a first step toward understanding these L. pneumophila-phagocyte interactions, we have studied the envelope of L. pneumophila Philadelphia 1 strain. We isolated cell envelopes by treating whole bacterial cells with lysozyme and EDTA to convert them to spheroplasts, then lysing the spheroplasts osmotically or sonically. We resolved the cell envelopes into two membrane fractions by isopycnic centrifugation. We localized NADH oxidase to the fraction of buoyant density 1.145, which we designated cytoplasmic membrane, and lipopolysaccharide (LPS) to the fraction of density 1.222, which we designated outer membrane. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the L. pneumophila outer membrane contains a single major protein species migrating at 28,000 mol wt; this is the major protein of the bacterium. The cytoplasmic membrane also contains a single major protein species migrating at 65,000 mol wt. Surface iodination of the bacteria and agglutination and immunofluorescence studies with rabbit antibody produced against the purified major outer membrane protein (MOMP) revealed that this protein is exposed at the cell surface. We isolated LPS from L. pneumophila membranes by SDS-EDTA treatment. The pattern obtained by subjecting the LPS to SDS-PAGE and staining the gel with silver nitrate suggests that L. pneumophila LPS might be atypical. We studied patient serologic responses to cell envelope components of L. pneumophila Philadelphia 1, a serogroup 1 organism. Sera from patients with evidence of infection with serogroup 1 L. pneumophila contained large amounts of antibody to this strain. Few of these antibodies recognized the MOMP of L. pneumophila. In contrast, greater than 98% of these antibodies were directed against the LPS. This indicates that LPS is the dominant serogroup antigen and the major antigen responsible for the reactivity of patient sera in the indirect fluorescent antibody assay, currently the principal diagnostic assay for Legionella infection.
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PMID:Isolation and characterization of the cytoplasmic and outer membranes of the Legionnaires' disease bacterium (Legionella pneumophila). 388 79

The antigens of the six serogroups of Legionella pneumophila were compared by two-dimensional (crossed) immunoelectrophoresis by using rabbit antisera to serogroups 1, 2, 3 and 4. The close relationship among the serogroups was shown by the fact that 27 of the 31 antigens demonstrated so far were common. However, distinctive group-specific antigens with slow electrophoretic mobility were observed for serogroups 1, 2, 3, and 4. When intact serogroup 1 organisms were extracted with EDTA, the group-specific antigen was recovered in a virtually pure form. The group-specific antigen was pronase resistant, heat stable, and amphiphilic and had a surface location, all of which are properties suggestive of lipopolysaccharide. L. pneumophila shared four to five antigens with Tatlockia micdadei (Legionella micdadei). The large number of common antigens in the serogroups of L. pneumophila has important implications for the specific detection of antigens and antibodies by fluorescent and other tagged antibody methods.
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PMID:Antigenic analysis of Legionella pneumophila and Tatlockia micdadei (Legionella micdadei) by two-dimensional (crossed) immunoelectrophoresis. 617 28

A species-specific antigen in Legionella pneumophila was identified by a monoclonal antibody in enzyme-linked immunosorbent and immunofluorescence assays of serogroups 1 through 8. The species-specific antigen was heat stable, and the molecular weight of the major band was 29,000 by immunoblot analysis. In direct immunofluorescence assays, the antigen was cryptic or only partly exposed on the surface of the cells but was effectively exposed by treating the cells with detergent and EDTA. The monoclonal antibody was utilized in direct immunofluorescence assays to specifically identify multiple cultures of L. pneumophila serogroups.
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PMID:Identification of a species-specific antigen in Legionella pneumophila by a monoclonal antibody. 639 9


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