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)

Data on the clinical and laboratory study involving 150 children with the verified diagnosis of pneumonia observed as inpatients within a period from 1984 to 1988 are presented. To elucidate the pneumonia etiology, blood sera to the causative agents of influenza and parainfluenza, adenovirus, RS virus, Mycoplasma pneumoniae and Legionella pneumophila were assayed. An increase in the number of neutralizing antibodies to L. pneumophila was observed in 17.3 per cent of the patients. The majority of them simultaneously showed positive serological shifts with respect to the respiratory viruses. A specific clinical picture of pneumonia in the patients with the confirmed legionella infection was stated. The description of the treatment results is retrospective.
Antibiot Khimioter 1990 Sep
PMID:[Clinical picture and treatment of Legionella pneumonia in children]. 227 89

The inhibitory and postantibacterial activities of pefloxacin, ciprofloxacin, and ofloxacin against virulent Legionella pneumophila serogroup 1 were evaluated in cell-free and cellular models. In the absence of macrophages (with the tissue culture medium alone), bacterial numbers remained unchanged at 24 h in the presence of 0.1 microgram of pefloxacin, ciprofloxacin, or ofloxacin per ml and 1.0 microgram of pefloxacin per ml, whereas they were reduced in the presence of 1.0 microgram of ciprofloxacin or ofloxacin per ml. Experiments to evaluate the postantibacterial effects of these drugs were therefore performed with concentrations of 0.1 microgram/ml. In the cell-free model, brief exposure (1 h) of bacteria to each antimicrobial agent resulted in a transient decrease in numbers followed by logarithmic growth. In the cellular model, all three drugs (at 0.1 and 1.0 microgram/ml) inhibited the intracellular multiplication of L. pneumophila. The intracellular postantibacterial effects of 0.1 microgram of pefloxacin, ciprofloxacin, and ofloxacin per ml, which were left in contact with L. pneumophila-infected human macrophages for 24 h, were evaluated at various times after removal of the drugs. Pefloxacin was found to exhibit a significant inhibitory effect at 72 h, whereas following the removal of ciprofloxacin and ofloxacin, rapid bacterial multiplication occurred, leading to the destruction of the macrophage monolayer within 48 h. Thus, while pefloxacin, ciprofloxacin, and ofloxacin all inhibited the multiplication of L. pneumophila in human monocyte-derived macrophages, only pefloxacin exhibited a prolonged postantibacterial effect.
Antimicrob Agents Chemother 1990 Sep
PMID:Comparative postantibacterial activities of pefloxacin, ciprofloxacin, and ofloxacin against intracellular multiplication of Legionella pneumophila serogroup 1. 228 86

The mip gene of Legionella pneumophila serogroup 1 strain AA100 encodes a 24-kilodalton surface protein (Mip) and enhances the abilities of L. pneumophila to parasitize human macrophages and to cause pneumonia in experimental animals. To determine whether this virulence factor is conserved in the genus Legionella, a large panel of Legionella strains was examined by Southern hybridization and immunoblot analyses for the presence and expression of mip-related sequences. Strains representing all 14 serogroups of L. pneumophila contained a mip gene and expressed a 24-kilodalton Mip protein. Although the isolates of the 29 other Legionella species did not hybridize with mip DNA probes under high-stringency conditions, they did so at reduced stringency. In support of the notion that these strains possess mip-like genes, these species each expressed a protein (24 to 31 kilodaltons in size) that reacted with specific Mip antisera. Moreover, the cloned mip analog from Legionella micdadei encoded the cross-reactive protein. Thus, mip is conserved and specific to L. pneumophila, but mip-like genes are present throughout the genus, perhaps potentiating the intracellular infectivity of all Legionella species.
Infect Immun 1990 Sep
PMID:Identification of mip-like genes in the genus Legionella. 238 27

Formalin-killed Legionella pneumophila bacterial cells, as well as a purified cell wall preparation (designated F-1 antigen) containing lipopolysaccharide (LPS), stimulated production of interferons (IFNs) in mouse spleen cell cultures. L. pneumophila whole-cell vaccine induced an IFN that was pH 2 labile and neutralized by anti-IFN-gamma indicating that IFN-gamma was the dominant form present. F-1 antigen induced a mixture of IFNs, depending upon the age of the culture and cell types present. In freshly prepared whole-spleen cultures and in 2-h adherent cultures, F-1 induced predominantly IFN-alpha/beta. In whole-spleen cultures that were allowed to age for 24 to 48 h before stimulation, F-1 was seen to induce mostly IFN-gamma, with low levels of IFN-alpha/beta present. Since only IFN-alpha/beta was produced in T-cell-depleted populations (at 2 h or at 48 h), it is suggested that T cells are responsible for IFN-gamma production in aged cultures. Additionally, heat-treated F-1, Escherichia coli LPS, and heat-treated E. coli LPS all induced similar levels of IFN-gamma in whole-splenocyte or nonadherent cell cultures which were incubated 48 h before stimulation. This suggests that LPS present in F-1 is responsible for IFN-gamma production and that an activated cell population is required. These results show that L. pneumophila antigens can induce the production of various types of IFN in mouse spleen cell cultures through several mechanisms.
Infect Immun 1985 Sep
PMID:Kinetics and characterization of interferon production by murine spleen cells stimulated with Legionella pneumophila antigens. 241 62

Three hundred random sputum samples were collected for analysis from cases of mild to severe respiratory infections and screened for Legionella pneumophila by both the culture method and also the direct fluorescent antigen test. In one third of the cases, blood specimen was also collected and screened for Legionella serum antibodies. With the direct fluorescent test it was possible to identify Legionella in 9% of the samples while the culture gave positive results in 4.3% of cases. Diagnostic antibody titers (1:256) were obtained in 12% of the samples while another 12% cases showed serum antibody titers of 1:64 to 1:128. In Pakistan where antibiotics are used extensively, the direct fluorescent examination of sputum samples gives more accurate diagnosis of Legionella cases than the culture method.
J Pak Med Assoc 1989 Sep
PMID:Legionella pneumophila: laboratory diagnosis in developing countries like Pakistan. 251 45

The activity of a new macrolide, TE-031 (A-56268), against Legionella pneumophila in vitro was superior to the activities of roxithromycin, erythromycin and josamycin. The tissue concentrations of TE-031 in guinea pigs after oral administration (20 mg/kg) was much higher than those of roxithromycin, erythromycin and josamycin. The maximum concentration of TE-031 was 107.0 mg/kg in the lung, and 1.4 mg/l in the serum. The uptake of macrolides by cells collected by bronchoalveolar lavage in guinea pigs was measured by a radioisotopic method. The maximum ratios of intracellular to extracellular concentration of TE-031, roxithromycin, josamycin and erythromycin were 71.9, 24.8, 39.7 and 7.9, respectively. In infected guinea pigs, with the exception of erythromycin, the ratios were reduced to approximately half the values in normal animals. TE-031 showed greater therapeutic efficacy against experimental L. pneumophila pneumonia than roxithromycin, erythromycin and josamycin. TE-031 is a promising drug for treatment of legionella pneumonia and should be investigated in a clinical study on human Legionnaires' disease.
J Antimicrob Chemother 1989 Sep
PMID:A new macrolide, TE-031 (A-56268), in treatment of experimental Legionnaires' disease. 253 Feb 1

A total of 163 strains, including 106 strains of Legionella pneumophila, 28 strains of Tatlockia micdadei, and 29 strains of other legionellae (including members of the proposed genus Fluoribacter), were studied. Ten tests which together could distinguish the genera previously proposed were identified. These tests included catalase-peroxidase, gelatinase, hippurate hydrolysis, starch hydrolysis, medium browning, acetoin production, oxidase, medium fluorescence, colony fluorescence, and the bromcresol purple spot test. T. micdadei strains were strongly catalase positive and bromcresol purple spot test positive and produced acetoin but otherwise were usually inert in the other tests. L. pneumophila and Fluoribacter species could usually be distinguished by strength of catalase activity, blue-white colony fluorescence (if present), and differences in frequency of hippurate hydrolysis, starch hydrolysis, yellow-green medium fluorescence, and, to a lesser extent, oxidase activity. With a simple algorithm and computer program, the overall accuracy was 98.8%.
J Clin Microbiol 1989 Sep
PMID:Application of numerical systematics to the phenotypic differentiation of legionellae. 255 May 14

Antineutrophil cytoplasmic antibodies (ANCA) are of established value in the diagnosis of Wegener's granulomatosis allowing early introduction of therapy. These patients are at risk of opportunistic infection, especially whilst receiving immunosuppressive drugs and this may mimic reactivation of disease. We present three cases of Wegener's granulomatosis complicated by opportunistic infection and assess the value of ANCA detection. Two presented with symptoms compatible with disease reactivation but ANCA were negative. One died with pulmonary infection due to Pneumocystis carinii, Aspergillus fumigatus and Herpes simplex. Transbronchial biopsy in the second case revealed Pneumocystis carinii. A third case had strongly positive serum ANCA at diagnosis but in addition pulmonary infection with Legionella pneumophila. ANCA detection is of value in patients with Wegener's granulomatosis, but the result must be interpreted in the full clinical context.
Respir Med 1989 Sep
PMID:Opportunistic infection and antineutrophil cytoplasm antibodies in Wegener's granulomatosis. 261 25

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.
Infect Immun 1989 Sep
PMID:Genetic, immunological, and cytotoxic comparisons of Legionella proteolytic activities. 266 84

Methods of assessing virulence of Legionella pneumophila, the etiologic agent of Legionnaires disease, include the infection of guinea pigs, fertile chicken eggs, and mammalian and protozoan cell cultures. Guinea pig assays, in particular, are expensive, laborious, or unsuitable for routine screening of Legionella isolates. We have developed a virulence assay that requires the enumeration of viruslike plaques which are the result of virulent L. pneumophila infecting mouse L929 cells. Each plaque is the consequence of the initial infection of an L cell with a single bacterium. A nonvirulent mutant derived from the serial passage of virulent L. pneumophila on Mueller-Hinton agar fails to survive within L cells and consequently fails to produce plaques.
J Clin Microbiol 1989 Sep
PMID:Plaque assay for virulent Legionella pneumophila. 267 92


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