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)

To enable effective use of phoA gene fusions in Legionella pneumophila, we constructed MudphoA, a derivative of the mini-Mu phage Mu dII4041, which is capable of generating gene fusions to the Escherichia coli alkaline phosphatase gene (EC 3.1.3.1). Although an existing fusion-generating transposon, TnphoA, has been a useful tool for studying secreted proteins in other bacteria, this transposon and other Tn5 derivatives transpose inefficiently in Legionella pneumophila, necessitating the construction of a more effective vector for use in this pathogen. Using MudphoA we generated fusions to an E. coli gene encoding a periplasmic protein and to an L. pneumophila gene encoding an outer membrane protein; both sets of fusions resulted in alkaline phosphatase activity. We have begun to use MudphoA to mutate secreted proteins of L. pneumophila specifically, since this subset of bacterial proteins is most likely to be involved in host-bacterial interactions. This modified transposon may be useful for studies of other bacteria that support transposition of Mu, but not Tn5, derivatives.
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PMID:PhoA gene fusions in Legionella pneumophila generated in vivo using a new transposon, MudphoA. 132 25

We have used immunocytochemical techniques and enzyme cytochemistry to examine the distribution of plasma membrane proteins during coiling phagocytosis of Legionella pneumophila and conventional phagocytosis of Escherichia coli. Whereas class I and class II major histocompatibility complex (MHC) molecules are relatively excluded from nascent phagosomes during conventional and coiling phagocytosis, the CR3 complement receptor persists in nascent phagosomes. The staining pattern for alkaline phosphatase activity resembles that of MHC molecules, with a marked exclusion of phosphatase activity from L. pneumophila coils and nascent phagosomes. The staining pattern for 5'-nucleotidase activity, on the other hand, resembles that of CR3 with intense staining in the inner layers of L. pneumophila coils. These results demonstrate that the cell has the ability to exclude selectively certain membrane proteins from the nascent phagosome during phagocytosis, thereby producing a phagosomal membrane markedly different from the plasma membrane from which it is derived.
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PMID:Membrane sorting during phagocytosis: selective exclusion of major histocompatibility complex molecules but not complement receptor CR3 during conventional and coiling phagocytosis. 156

In a prospective study of community-acquired pneumonias, 30 patients were diagnosed with Legionnaires' disease in 15 months. Clinical, laboratory and radiologic features of these patients are reviewed and compared with those who have pneumococcal pneumonia. Alcoholism, history of smoking, previous antimicrobial therapy, gastrointestinal and neurologic manifestations, elevations of serum transaminases, alkaline phosphatase and creatinine levels were more frequent in pneumonia due to Legionella pneumophila than in pneumococcal pneumonia. The presence of respiratory failure and radiologic progression were common findings that suggested L pneumophila as the etiologic agent of a community-acquired pneumonia. Development of respiratory failure was associated with involvement of several lobes and isolation of L pneumophila in any specimen. In 21 of 30 patients with Legionnaires' disease, L pneumophila was isolated from respiratory specimens. Overall mortality was 10 percent, but it increased to 27 percent in patients not treated with erythromycin initially.
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PMID:Legionella pneumophila. A cause of severe community-acquired pneumonia. 191 47

The authors report a nonradioactive adaptation of DNA hybridization technology for the direct detection of Legionella organisms in situ in routinely processed histologic specimens. The probe used consisted of synthetic oligodeoxynucleotides, complementary to the ribosomal RNA of all clinically relevant Legionella species, labeled with biotinylated dUTP at their 3' ends. By in situ DNA hybridization and detection with an avidin-alkaline phosphatase complex. Legionella was visualized by light microscopy within the alveoli of lung specimens in 9 of 13 direct fluorescent antibody- or culture-positive cases of Legionnaires' disease. No cross-hybridization was observed in lung specimens infected with Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae, or other pathogens. The authors' results illustrate a novel adaptation of in situ DNA hybridization techniques, usually used for viruses, to the detection of a bacterial organism. The method enables direct visualization of bacterial nucleic acid in infected tissues and may facilitate early diagnosis and treatment of legionellosis.
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PMID:Rapid diagnosis of Legionella infection by a nonisotopic in situ hybridization method. 202 27

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

A rapid method of assay, using a monoclonal antibody linked to alkaline phosphatase, was used for the detection of the Pontiac subgroup of Legionella pneumophila serogroup 1. It was tested for its specificity against 53 strains of Legionella recently isolated from the environment in Singapore and Malaysia. The specificity and sensitivity of this method of assay was confirmed, though there is some concern that the specificity was too narrow, and there are reservations about the criteria suggested for interpreting the results.
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PMID:The specificity of a rapid method of assay for the presence of Legionella species in water. 267 37

Monoclonal antibodies to FITC were produced and shown to be specific for the fluorochrome. Molecular weight marker proteins labelled with FITC could be detected after SDS-PAGE and transfer onto nitrocellulose using anti-FITC followed by an anti-mouse IgG-alkaline phosphatase conjugate. The molecular weight of an antigen common to Legionella pneumophila and recognised by a monoclonal antibody could be determined accurately on a Western blot when FITC labelled markers were used as internal standards. The FITC-anti-FITC system was shown to be extremely sensitive, detecting 23.7 amol of BSA-FITC conjugate (equivalent to 1.42 x 10(7) molecules of FITC) in a dot blot assay.
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PMID:A sensitive method of detecting proteins on dot and Western blots using a monoclonal antibody to FITC. 312 42

We describe a new species of Legionella represented by 10 strains isolated from industrial cooling towers. Legionella oakridgensis differed genetically from the other seven species of Legionella in DNA hybridization studies and differed serologically in direct fluorescent-antibody tests. The new species, unlike all other species except L. jordanis, did not require added L-cysteine for growth in serial transfer on charcoal-yeast extract agar. L. oakridgensis, as well as three other species tested, required L-cysteine for primary isolation from animal tissues. L. oakridgensis was the only species of Legionella that failed to produce alkaline phosphatase at pH 8.5. In all other respects, it resembled other species of Legionella, including having a high content of branched-chain cellular fatty acids and being pathogenic for guinea pigs. These bacteria have not yet been associated with human disease, but they are potential causes of legionellosis.
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PMID:Legionella oakridgensis: unusual new species isolated from cooling tower water. 683 Feb 17

Thirty-eight cultures of Legionella pneumophila isolated from surface waters were characterized by their morphological, tinctorial, biochemical, and serological properties and by their ability to produce disease in guinea pigs. Their susceptibility to antimicrobial agents also was tested. When they were compared with clinical isolates, no important differences were found between cultures from the two sources. Sodium hippurate hydrolysis, gelatin liquefaction, pigment formation, and beta-lactamase and alkaline phosphatase activity were useful in differentiating the four described species of Legionella. Hydrolysis of diacetylfluorescein and the inability to reduce nitrate help to distinguish Legionella species from other gram-negative bacterial rods.
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PMID:Characteristics of environmental isolates of Legionella pneumophila. 725 60

Microbial phosphatases are known or suspected to play a role in the pathogenesis of several intracellular pathogens, including Legionella micdadei. Legionella pneumophila also possess phosphatase activities, but their possible roles in cellular infection are unknown. We generated mutants of a serogroup 1 isolate of L. pneumophila that lack the major phosphatase. Isolation of a Pho- mutant after random mutagenesis with transposon MudII4041 allowed us to dissociate the major alkaline phosphatase (pH optimum approximately 8) from a minor acid phosphatase activity. Both activities were concentrated in the bacterial periplasm. The gene encoding the major alkaline phosphatase (pho) was cloned by expression in E. coli and used to generate a site directed mutation in two L. pneumophila strains. Each parent-mutant pair was compared in a U937 cell tissue culture assay for capacity to infect, lyse, and grow within mammalian cells. Although the parental stains differed in their U937 cell cytopathicity, neither was significantly more infective than its Pho- derivative, suggesting that the alkaline phosphatase activity is not essential for cellular infection. Because they are not attenuated, Pho- mutants can be used to generate gene fusions with E. coli alkaline phosphatase to study and secretion and cellular infectivity in L. pneumophila.
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PMID:Phosphatase-negative mutants of Legionella pneumophila and their behavior in mammalian cell infection. 786 53


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