Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 31-kilodalton (kDa) protein was solubilized from the peptidoglycan (PG) fraction of Legionella pneumophila after treatment with either N-acetylmuramidase from the fungus Chalaropsis sp. or with mutanolysin from Streptomyces globisporus. The protein exhibited a ladderlike banding pattern by autoradiography when radiolabeled [( 35S]cysteine or [35S]methionine) PG material was extensively treated with hen lysozyme. The banding patterns ranging between 31 and 45 kDa and between 55 and 60 kDa resolved as a single 31-kDa protein when the material was subsequently treated with N-acetylmuramidase. Analysis of the purified 31-kDa protein for diaminopimelic acid by gas chromatography revealed 1 mol of diaminopimelic acid per mol of protein. When outer membrane PG material containing the major outer membrane porin protein was treated with N-acetylmuramidase or mutanolysin, both the 28.5-kDa major outer membrane protein and the 31-kDa protein were solubilized from the PG material under reducing conditions. In the absence of 2-mercaptoethanol, a high-molecular-mass complex (100 kDa) was resolved. The results of this study indicate that a 31-kDa PG-bound protein is a major component of the cell wall of L. pneumophila whose function may be to anchor the major outer membrane protein to PG. Finally, a survey of other Legionella species and other serogroups of L. pneumophila suggested that PG-bound proteins may be a common feature of this genus.
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PMID:Characterization of a major 31-kilodalton peptidoglycan-bound protein of Legionella pneumophila. 233 3

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

Legionella pneumophila infection of guinea-pigs by the aerosol route with either of two strains, one (serogroup I) giving an acute the other (serogroup 3) giving a protracted illness, induced a pyrexia and similar pneumonic lesions. With both strains there was a bacteraemia with early decreases in serum iron and zinc and increases in serum copper concentrations. Marked changes in other serum components were evident only in those animals which had protracted illness (serogroup 3-infected animals). These included transient increases in aminotransferase, creatine kinase and sorbitol dehydrogenase activities and triglyceride levels, together with gradual decreases in alkaline phosphatase and leucine aminopeptidase activities. Serum lysozyme activity and acute-phase protein synthesis increased, as did the ratio of phenylalanine to tyrosine. The findings confirm the relevance of the aerosol-infected guinea-pig model for the investigation of the disease processes and evaluation of therapeutic measures for use in man.
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PMID:Clinical chemical responses to experimental airborne legionellosis in the guinea-pig. 258 May 46

Advances in computerized microscopy have resulted in image analysis systems that rapidly and precisely measure various aspects of cellular morphology and physiology. These systems-composed of a microscope and attached photomultiplier tube or camera, an image processor, and a computer-have been used to measure lysosomal enzymes, pH, and calcium within phagocytes; to detect viral nucleic acids in in situ hybridization preparations; and to quantitate rates of cellular movement. These experiments have shown that (1) the intracellular proliferation of virulent microorganisms is associated with reductions in acid phosphatase, beta-glucuronidase, and lysozyme activity; (2) virulent Toxoplasma gondii, Legionella pneumophila, and Nocardia asteroides inhibit phagosomal acidification; and (3) changes in intracellular calcium movement affect phagocytic function. These methods have also been used to detect the AIDS virus within cultured lymphocytes and to measure cellular chemotaxis and chemokinesis. Further advances in technology should produce improved microscopic image analysis systems with wider applications for the investigation of infectious diseases.
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PMID:Applications of computerized microscopic image analysis in infectious diseases. 328 Dec 25

Salmonella cytotoxin present in cell-free sonic lysates causes rounding and detachment of Chinese hamster ovary (CHO) cells. Although the precise role of this toxin in the pathogenesis of salmonellosis is unclear, cytotoxin production by Salmonella could account for tissue damage or possibly, facilitate invasion. A variety of other bacteria (e.g. Shigella, Escherichia, Legionella) have been shown to form soluble cytotoxins, many of which may be involved in pathogenesis. The data in this report indicate that the Salmonella cytotoxin in cell-free sonic lysates is firmly associated with cell membrane fragments that can be pelleted by ultracentrifugation (270,000 g for 2.4 h). Furthermore, lysozyme treatment of filter-sterilized sonic extracts of Salmonella species followed by isopycnic sucrose gradient ultracentrifugation allowed separation of the outer and inner membrane components. The outer membrane (OM) peak contained the cytotoxic activity when assayed for detachment of CHO cells. The importance of these data resides in the observation that the Salmonella cytotoxin is an outer membrane component. Its mere location places it in a position of direct contact with host cells and suggests a possible role in cell damage and/or invasion. Furthermore, ultracentrifugation provides a method by which much of the Salmonella cytotoxin in sonic extracts can be removed allowing expression of the Salmonella enterotoxin, whose CHO cell elongation effect is usually obscured by the presence of the cytotoxin causing cell rounding and detachment.
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PMID:Salmonella cytotoxin: a component of the bacterial outer membrane. 350 97

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

Legionella pneumophila and related species were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis for outer membrane proteins. Of the 10 species examined, 9 contained a 24-kilodalton (kDa) major outer membrane protein (MOMP) that was resolvable only when outer membrane material was heated in the presence of 2-mercaptoethanol. Labeling studies with [35S]cysteine indicated that the protein contained cysteine, and disulfide cross-linking of the unreduced complex was demonstrated by labeling with iodoacetamide. The unreduced outer membrane preparation contained peptidoglycan, and after treatment with lysozyme to remove peptidoglycan, a protein complex of 95 kDa was observed by sodium dodecyl sulfate polyacrylamide gel electrophoresis in the absence of 2-mercaptoethanol. Reduction of the 95-kDa complex yielded 24-kDa monomers, suggesting that the 95-kDa complex was composed of four subunits. The 24-kDa MOMP from L. pneumophila was purified, and antibody produced to this protein cross-reacted with all species of Legionella as determined from an immunoblot of a sodium dodecyl sulfate gel. Only serogroup 1 strains of L. bozemanii lacked the 24-kDa MOMP and showed no cross-reactivity. These results suggest that the 24-kDa MOMP common to most species of Legionella contains a genus-specific epitope.
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PMID:Disulfide-bonded outer membrane proteins in the genus Legionella. 398 79

Peptidoglycan (PG) from Legionella pneumophila was composed of muramic acid, glucosamine, glutamic acid, alanine, and meso-diaminopimelic acid in a molar ratio of 0.8:0.8:1.1:1.7:1. Partially purified PG contained trypsin-insensitive proteins which were extracted by 1 N NaOH hydrolysis without apparent dissolution of the PG. Lysozyme hydrolysis of purified PG or cell walls caused an increase in reducing groups which correlated with roughly 70 to 100% digestion of disaccharides. However, there was no significant decrease in turbidity during lysozyme hydrolysis of purified PG or cell wall. Additionally, 80 to 90% of the meso-diaminopimelic acid epsilon-amino groups were not susceptible to dinitrophenylation. Collectively, the PG of L. pneumophila was sensitive to lysozyme hydrolysis and insensitive to alkali dissolution, and 80 to 90% of the NH2 groups of meso-diaminopimelic acid were apparently involved in cross-linkages between peptides.
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PMID:Peptidoglycan of Legionella pneumophila: apparent resistance to lysozyme hydrolysis correlates with a high degree of peptide cross-linking. 612 41

68 children aged 3-7 years, undergoing general sanative treatment in a bronchopulmonary sanatorium in the vicinity of Moscow between November 10 and December 29, 1990, were examined. During the stay of these children in the sanatorium cases of respiratory diseases, mainly of parainfluenza etiology, were registered, which was confirmed by serological laboratory studies. At this season no cases of Legionella and Mycoplasma infections were detected. The necessity of taking prophylactic measures with the use of reaferon and lysozyme in sanative groups of children in due time, starting from the first day of the formation of such group, was substantiated.
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PMID:[The seroepidemiological aspects of respiratory diseases and the prospects for their prevention in organized children's sanatorium-type collectives]. 818 8

The relationship between Legionella and protist hosts has a huge impact when considering the infectious risk in humans because it facilitates the long-term replication and survival of Legionella in the environment. The ciliate Paramecium is considered to be a protist host for Legionella in natural environments, but the details of their endosymbiosis are largely unknown. In this study, we determined candidate Legionella pneumophila genes that are likely to be involved in the establishment of endosymbiosis in Paramecium caudatum by comparing the genomes of Legionella spp. and Holospora spp. that are obligate endosymbiotic bacteria in Paramecium spp. Among the candidate genes, each single deletion mutant for five genes (lpg0492, lpg0522, lpg0523, lpg2141 and lpg2398) failed to establish endosymbiosis in P. caudatum despite showing intracellular growth in human macrophages. The mutants exhibited no characteristic changes in terms of their morphology, multiplication rate or capacity for modulating the phagosomes in which they were contained, but their resistance to lysozyme decreased significantly. This study provides insights into novel factors required by L. pneumophila for endosymbiosis in P. caudatum, and suggests that endosymbiotic organisms within conspecific hosts may have shared genes related to effective endosymbiosis establishment.
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PMID:Identification of novel Legionella genes required for endosymbiosis in Paramecium based on comparative genome analysis with Holospora spp. 3012 11


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