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

Yolk sac suspensions infected with the Legionnaires disease bacterium (LDB) were plated onto 17 different bacteriological agar media. The LDB grew only on Mueller-Hinton agar supplemented with 1% Iso Vitale X and 1% hemoglobin (MH-IH). This medium was subsequently analyzed to determine the components required to support growth of the LDB. L-Cysteine hydrochloride can replace the Iso Vitale X reagent, and soluble ferric pyrophosphate can replace hemoglobin. A new medium, F-G agar, was formulated incorporating these chemicals. Different cultures conditions (oxygen tension, temperature, and pH) were also evaluated. The LDB grew optimally at 35 degrees C under 2.5% CO2 on the F-G agar adjusted to pH 6.9. When infected tissues were inoculated onto both F-G agar and MH-IH, the F-G agar produced colonies of the LDB more rapidly and in greater numbers than did MH-IH.
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PMID:Primary isolation media for Legionnaires disease bacterium. 2 11

A chemically defined liquid medium has been developed for the study of the physiology and antigen production of the Legionnaires disease bacterium. The medium contains basal salts, vitamins, alpha-ketoglutaric acid, pyruvate, 0.05% l-cysteine, 0.05% glutathione, and a mixture of 20 additional amino acids, each of 0.01% final concentration, except serine, which was at 0.1%. The medium in shake culture at 37 degrees C with increased CO2 at pH 6.5, supports the maximum rate of growth, the highest cell yields, and the maximum cell surface antigen as distinguished by specific fluorescein isothiocyanate-conjugated antibody. Studies during the development of this medium showed that CO2, pyruvate, and alpha-ketoglutarate strongly stimulated growth; that cysteine and methionine were required for growth; and that serine, threonine, histidine, tyrosine, and tryptophane were energy sources. Glutathione substituted for cysteine, but cystine did not. The organisms did not use glucose and polysaccharides, as judged by cell yields when these carbohydrates were present or absent. The chelators malate, citrate, and ethylenediaminetetraacetic acid totally inhibited growth. Beta-mercaptoethanol, thioglycolate, dithiothreitol, and Tween 80 (0.05%) inhibited growth strongly or completely. Catalase activity was extremely weak or absent. Morphology varied, depending upon conditions and phases of growth. In general, filamentous forms became chains of cigar-shaped bacilli fragmenting to pairs and becoming coccoidal in the late stationary pha-e of growth. The organism grew at 25, 30, and 37 degrees C. Although they varied in their growth characteristics, 10 isolates were passed for five transfers in the chemically defined broth, giving maximum rates of growth, cell yields, and antigen production.
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PMID:Development of a chemically defined liquid medium for growth of Legionella pneumophila. 3 86

Clinical, pulmonary, and serologic findings in Legionnaires who attended the 1976 American Legion Convention in Philadelphia were studied 2 years after the Legionnaires' disease epidemic there. All 31 survivors of Legionnaires' disease studied became ill within 2 weeks after the convention, and 18 had not fully recovered 2 years after the epidemic. Twenty-five (28%) of 90 additional Legionnaires exposed at the convention but not diagnosed as having Legionnaires' disease became ill during the same time interval; five of these had symptoms during the next 2 years. Survivors had decreased diffusion capacities measured by the carbon monoxide single-breath method. These differences could not be accounted for by ventilation abnormalities or concurrent illness. Significant levels of IgG or IgM antibodies persisted in 94% of survivors of Legionnaires' disease and in 53% of Legionnaires exposed at the convention, which suggests a high prevalence of subclinical infection. Persistence of IgM antibody raises the question of latency or subclinical infection as part of the natural history of Legionnaires' disease.
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PMID:The Philadelphia epidemic of Legionnaire's disease: clinical, pulmonary, and serologic findings two years later. 37 42

This article summarizes the health effects of indoor air pollutants and the modalities available to control them. The pollutants discussed include active and passive exposure to tobacco smoke; combustion products of carbon monoxide; nitrogen dioxide; products of biofuels, including wood and coal; biologic agents leading to immune responses, such as house dust mites, cockroaches, fungi, animal dander, and urine; biologic agents associated with infection such as Legionella and tuberculosis; formaldehyde; and volatile organic compounds. An approach to assessing building-related illness and "tight building" syndrome is presented. Finally, the article reviews recent data on hospital-related asthma and exposures to potential respiratory hazards such as antineoplastic agents, anesthetic gases, and ethylene oxide.
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PMID:Indoor air pollution. 151 50

Two male patients ages 54 and 58 years had persisting pneumonia with dry cough, dyspnea, weight loss, and fever up to 39 degrees C that did not respond to erythromycin treatment. There was extensive restrictive impairment of ventilation and loss of diffusing capacity for carbon monoxide. Histologic examination of the basal pulmonary infiltrates showed fibrosing alveolitis. Serologic titers indicated that the patients had suffered from Legionella pneumophila infection. We believe that Legionella had caused the fibrosing alveolitis since there was absence of any other causative agents or factors. Both patients responded to corticosteroid treatment with rapid clinical improvement but delayed radiologic regression.
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PMID:Fibrosing alveolitis responsive to corticosteroids following Legionnaires' disease pneumonia. 812 53

Indole-3-propionic acid (IPA), a phytohormone derivative, is a potent inhibitor of growth of Legionella pneumophila cultivated extracellularly in a chemically defined hypotonic medium and intracellularly in human monocytes. The inhibitory activity turns into bactericidal activity with increasing concentrations. The susceptibility of the microorganism to IPA was more evident in "fast-growing" cultures (under conditions of vigorous shaking) than in static cultures growing under an atmosphere of 5% CO2-95% air, which resulted in a decreased growth rate. The MIC, after incubation with the drug for 48 h and as determined by counting of the CFU, was 1.58 microM for fast-growing cultures and 2.64 microM for those grown under static conditions. The MBCs were 5.28 and 26.43 microM, respectively. Tryptophan (Trp) at 150 microM prevented the inhibition caused by 2.64 microM IPA, increased the MIC about 3-fold, and increased the MBC by 10-fold. The effect of Trp was less remarkable in "slow-growing" cultures. The susceptibility of L. pneumophila proliferating in human monocytes was markedly lower than that when it was cultivated extracellularly in the chemically defined hypotonic medium. The MIC after incubation for 48 h was 5.28 microM, and a decrease in viable count was achieved with 105.70 microM. The lower susceptibility was apparently due (at least partially) to the presence of Trp (24.50 microM) in the RPMI 1640 medium that was used for the monocyte cultures. The effect of IPA was time dependent, and prolonged exposure enhanced the bactericidal activity and turned the inhibitory dose into a bactericidal dose. The present data demonstrate that IPA is a potent anti-L. pneumophila factor, although it has a markedly lower activity against bacteria growing intracellularly compared with its activity against extracellularly proliferating microorganisms.
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PMID:Susceptibility of Legionella pneumophila grown extracellularly and in human monocytes to indole-3-propionic acid. 181 Jan 85

Cytotoxic activity assays of Gram-negative, heterotrophic bacteria are often laborious and time consuming. The objective of this study was to develop in situ procedures for testing potential cytotoxic activities of heterotrophic bacteria isolated from drinking water systems. Water samples were passed through 0.45 microns membrane filters which were then placed upon appropriate media incubated. After incubation, each membrane filter was transferred to the surface of Y-1 mouse adrenal cells overlaid with 1% agar. The filters were removed after exposure for 15 min. The Y-1 cells were then incubated at 37 degrees C in 2.5% CO2 for an additional 24 h. The release of putative cytotoxic and cytotonic products from the bacterial colonies was recognized by zones of cellular lysis and injury of Y-1 cells that appeared immediately beneath the membrane. Cytotoxic strains of Aeromonas, Vibrio, Escherichia, and Legionella spp. were readily recognized by this method. About 1% of the bacteria isolated from drinking water also released cytotoxic products. This frequency was dependent upon the primary medium used and the density of bacteria present. The majority of cytotoxic strains isolated from drinking water also expressed protease activity (95%) and haemolytic activity (70%). This in situ membrane filter procedure is a facile method for simultaneously testing many different bacterial colonies.
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PMID:A membrane filter procedure for assaying cytotoxic activity in heterotrophic bacteria isolated from drinking water. 201 13

Forty eyewash units were sampled for protozoa, bacteria, and fungi. Total heterotrophic bacterial counts on nutrient agar and R2A agar (Difco Laboratories, Detroit, Mich.) ranged from 0 to 10(5) CFU/ml, with Pseudomonas spp. being the most frequently isolated. Total counts of 10(4) and 10(8) cells per ml were obtained with the acridine orange staining procedure. All samples were examined for Legionella spp. by direct fluorescent-antibody staining and by culturing on buffered charcoal-yeast extract agar containing alpha-ketoglutarate and glycine and supplemented with cycloheximide, vancomycin, and polymyxin B. DNA-DNA hybridization was used to confirm identification of the Legionella isolates. Legionellae were detected in 35 of 40 (87.5%) samples by direct fluorescent-antibody staining, with 3 samples yielding both Legionella spp. and amoebae. Amoebae identified as Hartmannella, Vahlkampfia, Acanthamoeba, and Cochliopodium spp. were detected in 19 of 40 (47:5%) samples. Sabouraud dextrose agar was used to obtain a crude estimate of viable fungal populations, pH, hardness, and ammonia, alkalinity, chlorine, copper, and iron contents were recorded for all water samples collected from eyewash stations; 33% of the samples had greater than or equal to 10 mg of CO2 per liter. It is concluded that eyewash stations not regularly flushed and/or cleaned and used to flush traumatized eye tissue may be a source of infection and can contaminate laboratory environments via aerosol transmission.
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PMID:Isolation of amoebae and Pseudomonas and Legionella spp. from eyewash stations. 203 3

A number of measures were taken to control Legionella pneumophila in a hospital hot water system over a period of 18 months, including (i) raising the temperature of the water leaving the central storage tanks from initially 55-60 degrees C to approximately 73 degrees C, (ii) heat shock treatment of the whole system with water temperatures above 70 degrees C and (iii) increasing the daily return flow from the hospital circulation system from initially 30 m3 to 120 m3. In addition, (iv) three UV irradiation devices were installed on the inlet and outlets of the storage tanks and (v) an attempt was made to decontaminate the water system by means of CO2. Measures (i) and (iii) were demonstrated to be effective for permanent control of Legionellae in the system. Measures (ii) and (v) proved to have only a short term effect of several days and measure (iv) did not show any effect on the presence of Legionellae at all. The extent of Legionella contamination of the water samples correlated negatively with water temperature and depended on the position of the outlets within the hospital. Different pipe materials (copper, plastics) could not be shown to have any influence on the extent of water contamination with Legionella. The findings of the survey indicate that especially the peripheral areas of the hot water system were colonized by Legionellae.
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PMID:[Sanitizing a hospital hot water system contaminated with Legionella pneumophila]. 211 57

Since the discovery of Legionella pneumophila in the late 1970s, this organism and other Legionella sp have been an important cause of pneumonia in solid organ transplant recipients. Legionella sp are obligate aerobes that require a source of amino acids, iron, and L-cystine. Growth is enhanced in a 5% CO2 atmosphere at 37 degrees C in the presence of charcoal. Legionella sp reside in water supplies and hospital outbreaks associated with contaminated water have been described. Transplant recipients are particularly susceptible to Legionella infection. Legionella pneumonia tends to occur within several weeks after transplantation and frequently coincides with episodes of rejection. A prodrome of influenza-like symptoms is followed by a sometimes "explosive" pneumonia with patchy lobular or interstitial infiltrates on chest radiograph. High fever, abdominal pain, and mental status changes are sometimes seen. Diagnosis is made by examination of respiratory secretions by the direct fluorescent antibody technique or culture of the organism. Intravenous erythromycin is the treatment of choice. Rifampin is added if there is a lack of response. Both erythromycin and rifampin have important and opposite effects on cyclosporine metabolism, which may result, respectively, in increased cyclosporine toxicity or graft loss. Patients who must continue cyclosporine will, therefore, require frequent monitoring of cyclosporine levels.
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PMID:Legionella infection in transplant patients. 218 18


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