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)

Transposon Tn5 was introduced into Legionella pneumophila on plasmid pRK340, which is temperature sensitive for plasmid maintenance. The presence of plasmid DNA was confirmed by agarose gel electrophoresis and by conjugal transfer of the plasmid to Escherichia coli. Tn5 insertions were obtained by culturing L. pneumophila at the nonpermissive temperature (43 degrees C) on buffered charcoal-yeast extract agar containing kanamycin. Of the 260 kanamycin-resistant colonies picked, 220 failed to conjugate pRK340 to E. coli. Plasmid DNA was not visualized from eight randomly picked Tn5-containing strains, and Southern hybridizations indicated that Tn5, but not pRK340, inserted into multiple sites in the Legionella chromosome. In addition, the streptomycin resistance determinant on Tn5 was expressed in L. pneumophila.
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PMID:Broad-host-range plasmid pRK340 delivers Tn5 into the Legionella pneumophila chromosome. 298 91

An assay for plasmid DNA content was carried out in 100 strains of Legionella pneumophila of distinct serogroups and isolated from various sources (clinical, environment). The strains were isolated from different geographic regions in our country. The presence of plasmids was proved in one of the 11 clinical isolates and in 68 of the 89 isolated of environmental origin studied. In the strains belonging to serogroup 1 and isolated in our region (Cantabria), three plasmid profiles were observed, whereas in strains of the same serogroup from other geographic regions, two profiles were shown which exhibited differences compared to the former ones. Analysis by means of restriction endonucleases suggested that plasmids of similar size in serogroup 1 strains of different source, were related. The results obtained do not appear to reveal any correlation between plasmid profile and source of isolation or serogroup.
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PMID:Plasmid profiles of Legionella pneumophila strains isolated in Spain. 302 21

The antibacterial activity of ofloxacin against Enterobacteriaceae, Pseudomonas aeruginosa, Haemophilus influenzae, Branhamella catarrhalis, and Neisseria gonorrhoeae was comparable to norfloxacin and enoxacin, and far exceeded the activity of pipemidic acid and nalidixic acid. The activity of ofloxacin was two to eight times less than that of ciprofloxacin. Ofloxacin was more active against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Acinetobacter spp., Legionella spp., and Bacteroides fragilis, than norfloxacin, enoxacin, pipemidic acid and nalidixic acid, and the activity of ofloxacin was comparable to that of ciprofloxacin. Ofloxacin was two to seven times more effective than norfloxacin in systemic infections in mice with S. aureus, Escherichia coli, Serratia marcescens and P. aeruginosa. Ofloxacin strongly inhibited DNA supercoiling activity of DNA gyrase purified from E. coli KL-16. There is a parallel relationship between antibacterial activity of ofloxacin and its inhibitory action against DNA gyrases from ofloxacin-susceptible and ofloxacin-resistant clinical isolates of E. coli. These results indicate that the high bactericidal action of ofloxacin and the related new quinolone agents can be explained by their potent inhibitory activities against DNA gyrase in bacterial cells.
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PMID:Antibacterial activity of ofloxacin and its mode of action. 302 66

Pneumonia/influenza is one of the top ten leading causes of mortality in the United States each year. The identification of the etiologic agent responsible for lower respiratory tract infection plays an important role in the proper management of this clinical problem. The specimens submitted for evaluation are obtained in diverse ways and include expectorated sputum, material from transtracheal and bronchoscopic procedures, pleural fluid and lung aspirates, and biopsy of actual lung tissue. Processing of material can include stained smears, aerobic and anaerobic cultures, and special processing techniques for fungal, viral, Pneumocystis carinii, Legionella, mycobacterial, and mycoplasma identification. Modifications of smear preparation techniques and application of the new DNA probe technology are providing the opportunity for rapid microbiologic testing of clinical specimens with increased sensitivity and specificity, often obviating the need for invasive diagnostic procedures. Laboratory methodology is continually undergoing technological change, and optimal care of the patient with pneumonia requires close cooperation between the attending physician and the clinical laboratory.
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PMID:Using the microbiology laboratory in the diagnosis of pneumonia. 304 11

Between 11 November 1986 and 28 February 1987, legionellosis was diagnosed in 23 patients at one hospital with a recently marketed Legionella-specific DNA probe for respiratory secretions. Only 10 of the 23 probe-positive patients showed findings typical of Legionella pneumonia, including a temperature of greater than or equal to 100.5 degrees F (approximately 38.1 degrees C) and radiographic evidence of pneumonia. No differences were found in the results of laboratory studies, demographic features, or underlying risk factors for these 10 probe-positive patients when compared with the 13 probe-positive patients with nonpneumonic illnesses. A case-control study comparing probe-positive and -negative patients failed to identify any different features of disease or epidemiologic characteristics. Probes of repeat specimens of sputum were still positive 2 to 13 weeks after the initial test in 5 (50%) of the 10 probe-positive patients. The clinical features in most patients were atypical for legionellosis, and the diagnosis could not be confirmed by traditional laboratory tests performed on duplicate specimens processed at the Centers for Disease Control. This report emphasizes the need for clinical microbiology laboratories to confirm test results from new procedures by accepted diagnostic methods.
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PMID:False-positive DNA probe test for Legionella species associated with a cluster of respiratory illnesses. 304 52

Previous DNA relatedness and enzyme electrophoretic mobility studies indicated heterogeneity among strains of Legionella pneumophila serogroups 1, 4, 5, and Lansing 3 (a new, as yet unnumbered serogroup). In this study 60 L. pneumophila strains were studied by DNA hybridization (hydroxyapatite method) to assess their genomic relatedness. These strains were also studied biochemically and serologically to determine whether they formed one or more phenotypic groups. DNA relatedness studies identified three groups. DNA group 1 contained the type strain Philadelphia 1 and strains from serogroups 1 through 14 of L. pneumophila. The average relatedness of DNA group 1 strains was 88% at 60 degrees C with 1.1% divergence in related sequences and 85% at 75 degrees C. DNA group 2 contained strain Los Angeles 1, the reference strain of serogroup 4, and strains of serogroups 1, 4, 5, and Lansing 3, an unnumbered serogroup. Average relatedness of DNA group 2 strains was 84% at 60 degrees C with 0.7% divergence and 87% at 75 degrees C. Reciprocal relatedness of DNA groups 1 and 2 was approximately 67% at 60 degrees C with 6.0% divergence and 48% at 75 degrees C. DNA group 3 strains were in serogroup 5. They were 98% related at 60 degrees C with 0.5% divergence and 97% related at 75 degrees C. Reciprocal relatedness of DNA group 3 and DNA group 1 was approximately 74% at 60 degrees C with 5.3% divergence and 43% at 75 degrees C, and reciprocal relatedness of DNA groups 3 and 2 was 66% at 60 degrees C with 5.7% divergence and 55% at 75 degrees C. The DNA groups could not be separated biochemically or serologically or by cell wall fatty acid and isoprenoid quinone composition. Three subspecies of L. pneumophila are proposed to accommodate the three DNA groups: L. pneumophila subsp. pneumophila subsp. nov. for DNA group 1, L. pneumophila subsp. fraseri subsp. nov. for DNA group 2, and pneumophila subsp. pascullei subsp. nov. for DNA group 3.
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PMID:Legionella pneumophila serogroup Lansing 3 isolated from a patient with fatal pneumonia, and descriptions of L. pneumophila subsp. pneumophila subsp. nov., L. pneumophila subsp. fraseri subsp. nov., and L. pneumophila subsp. pascullei subsp. nov. 305 73

A prospective evaluation of a DNA probe assay for detection of Legionella species was performed on 427 consecutive respiratory specimens submitted over an 18-month period. The Gen-Probe assay utilizing both low (greater than or equal to 4.0) and high (greater than 7.0) ratio threshold values was compared to direct fluorescent antibody staining (DFA) as a predictor of isolation of Legionella on culture. The highest sensitivity (63%) was obtained with the lower threshold ratio, but was not significantly different from the result obtained with a threshold ratio of greater than 7.0 (50%, p = 0.722) or DFA results (44%, p = 0.479). The specificity of the DNA probe assay was improved with the high threshold (99%) compared either to the low threshold ratio (95%, p = 0.002) or DFA (97%, p = 0.055). When the DNA probe was compared to DFA and/or Legionella isolation on culture, a significantly lower specificity (97% versus 99%, p = 0.0006) and higher sensitivity (74% versus 37%, p = 0.013) was obtained with a threshold value of greater than or equal to 4.0 than greater than 7.0. Ten of 20 specimens with a DNA probe ratio between 4.0 and 7.0 were DFA positive, although only two were isolated on culture. The DFA assay and both probe threshold ratios have a high negative predictive value when compared to culture. However, only the threshold ratio of greater than 7.0 has a sufficiently high positive predictive value to be useful alone.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Prospective evaluation of the Gen-Probe assay for detection of legionellae in respiratory specimens. 314 56

The fatty acids and ubiquinones of 44 reference strains corresponding to species of Legionella and 3 strains of Legionella isolated in the environment have been evaluated. The analysis of fatty acids profiles allows a classification of 22 species into 4 groups depending on the predominance of some branched-chain fatty acids of linear fatty acids. As for ubiquinones our results for the 22 species corroborate the classification in 5 groups established by Moss in 1983 based on the study of 10 species of Legionella. The analysis of fatty acids composition combined with ubiquinones content has allowed us to identify the antigenically similar strains which cannot be differentiated by direct immunofluorescence on one hand (strain 1) and on the other a more precise approach to the identification, before DNA-ADN hybridization of strains of new species (strains 2).
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PMID:[Identification of Legionella by gas phase chromatography of fatty acids and high performance liquid chromatography of ubiquinones]. 317 76

Two Legionella-like organisms were isolated from cooling-tower water samples in Czechoslovakia. They were presumptively identified as legionellae by their growth on buffered charcoal-yeast extract agar (BCYE) containing L-cysteine and their absence of growth on BCYE without L-cysteine. Both strains contained predominately branch-chained cellular fatty acids and were therefore definitively placed in the genus Legionella. They were serologically distinct from other described Legionella species and were shown by DNA studies to constitute two new Legionella species, Legionella moravica (type strain 316-36; ATCC 43877) and Legionella brunensis (type strain 441-1; ATCC 43878).
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PMID:Legionella moravica sp. nov. and Legionella brunensis sp. nov. isolated from cooling-tower water. 317 63

Legionella gormanii, previously isolated only from the environment, was grown from the bronchial brush specimen of a patient with pneumonia. The organism was characterized by serologic, biochemical, and DNA hybridization studies.
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PMID:First isolation of Legionella gormanii from human disease. 327


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