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

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

The activities of fleroxacin against 22 clinical Legionella isolates were determined by agar and broth microdilution susceptibility testing. The fleroxacin MIC required to inhibit 90% of strains tested on buffered charcoal yeast extract agar medium supplemented with 0.1% alpha-ketoglutarate was 0.64 micrograms/ml and was 0.04 microgram/ml when testing was done with buffered yeast extract broth supplemented with 0.1% alpha-ketoglutarate. Fleroxacin (0.25 microgram/ml) reduced the bacterial counts of two L. pneumophila strains grown in guinea pig alveolar macrophages by 1 log10 CFU/ml, but regrowth occurred over a 3-day period; fleroxacin was significantly more active than erythromycin in this assay. Single-dose (10 mg/kg of body weight given intraperitoneally) pharmacokinetic studies performed in guinea pigs with L. pneumophila pneumonia revealed peak levels in plasma and lungs to be 3.3 micrograms/ml and 3.5 micrograms/g, respectively, at 0.5 h and 0.8 microgram/ml and 0.8 microgram/g, respectively, at 1 h. The half-life of the terminal phase of elimination from plasma and lung was approximately 2 h. All 17 infected guinea pigs treated with fleroxacin (10 mg/kg/day) for 2 days survived for 14 days post-antimicrobial therapy, as did all 16 guinea pigs treated with the same dose of fleroxacin for 5 days. Only 1 of 16 animals treated with saline survived. The animals treated with fleroxacin for 2 days lost more weight and had higher temperatures than those treated with the antibiotic for 5 days. Fleroxacin is effective against L. pneumophila in vitro and in a guinea pig model of Legionnaires' disease. Fleroxacin should be evaluated as a treatment for human Legionnaires' disease.
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PMID:In vitro activities of fleroxacin against clinical isolates of Legionella spp., its pharmacokinetics in guinea pigs, and use to treat guinea pigs with L. pneumophila pneumonia. 148 82

The effect of agar type used for buffered charcoal yeast extract medium supplemented with 0.1% alpha-ketoglutarate was tested based on the growth and size of Legionella pneumophila. Oxoid Agar no. 1, Difco Bacto and Bitek agars, and BBL Granulated, Grade A, and Select agars were tested. For colony size the agars were ranked in the following order: Oxoid agar no. 1 much greater than Bacto greater than Bitek approximately Granulated approximately Grade A greater than Select. Colony yield per plate was similar for all agars except for Grade A, which gave significantly fewer colonies after 3 days, but not 4 days, of incubation. Agar type significantly influences L. pneumophila growth on buffered charcoal yeast extract medium supplemented with 0.1% alpha-ketoglutarate.
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PMID:Comparison of different agars used in the formulation of buffered charcoal yeast extract medium. 199 56

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

The activities of sparfloxacin, ciprofloxacin, and erythromycin for 21 clinical Legionella isolates were determined by agar and broth dilution susceptibility testing and by growth inhibition assays in guinea pig alveolar macrophages (sparfloxacin and ciprofloxacin). All three antimicrobial agents had roughly equivalent activities when buffered charcoal yeast extract agar medium supplemented with 0.1% alpha-ketoglutarate was used as the test medium; the MICs for 90% of strains were 1.0 micrograms/ml for erythromycin and sparfloxacin and 0.5 microgram/ml for ciprofloxacin. Buffered charcoal yeast extract medium supplemented with 0.1% alpha-ketoglutarate inhibited the activities of all the antimicrobial agents tested, as judged by the susceptibility of a control Staphylococcus aureus strain. Broth macrodilution MICs for two L. pneumophila strains in buffered yeast extract supplemented with 0.1% alpha-ketoglutarate were less than or equal to 0.03 microgram/ml for sparfloxacin, 0.06 microgram/ml for ciprofloxacin, and 0.25 microgram/ml for erythromycin; only erythromycin was inhibited by this medium. Ciprofloxacin and sparfloxacin (both 0.25 microgram/ml) reduced bacterial counts of two L. pneumophila strains grown in guinea pig alveolar macrophages by 2 log10 CFU/ml, but regrowth occurred over a 3-day period. Sparfloxacin, but not ciprofloxacin (both 1 microgram/ml), caused a 3- to 4-day postantibiotic effect. Pharmacokinetic and therapy studies of sparfloxacin were performed in guinea pigs with L. pneumophila pneumonia. For the pharmacokinetic study, sparfloxacin was given (10 mg/kg of body weight) to infected guinea pigs by the intraperitoneal route; peak levels in serum and lung were 2.6 micrograms/ml and 1.6 micrograms/g, respectively, at 1 h, with a terminal-phase half-life of elimination from serum of 5 h.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:In vitro activity of sparfloxacin (CI-978; AT-4140) for clinical Legionella isolates, pharmacokinetics in guinea pigs, and use to treat guinea pigs with L. pneumophila pneumonia. 207 1

The recovery of Legionella micdadei and L. bozemanii serogroups 1 and 2 from infected guinea pig spleens was evaluated by using two culture media: buffered charcoal yeast extract agar with 0.1% alpha-ketoglutarate (BCYE alpha) and the same medium supplemented with 1% bovine serum albumin (ABCYE alpha). At the lowest dilution of spleen tissue (10(-1)), recovery of all strains of L. micdadei and L. bozemanii was more efficient on ABCYE alpha than on BCYE alpha. L. micdadei strains had higher recovery rates on ABCYE alpha after another 10-fold dilution, but recoveries of L. bozemanii were similar on both media. Recovery rates for most test strains were comparable on BCYE alpha and ABCYE alpha at the highest dilution (10(-3)) of tissue tested. The presence of albumin in BCYE alpha increased the recovery rate of L. micdadei more than that of L. bozemanii. The use of ABCYE alpha medium in place of BCYE alpha may improve the recovery of L. micdadei and L. bozemanii from clinical specimens. Preliminary studies indicate that this medium also enhances recovery of certain Legionella spp. from environmental samples.
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PMID:Increased recovery of Legionella micdadei and Legionella bozemanii on buffered charcoal yeast extract agar supplemented with albumin. 232 82

Agar dilution minimum inhibitory concentrations (MICs) of lomefloxacin (LO), ciprofloxacin (CI), and erythromycin (ER) were determined for 100 clinical isolates of Legionella using buffered charcoal yeast extract medium supplemented with alpha-ketoglutarate (BCYEa). The Legionella strains tested included 84 L. pneumophila, 2 L. micdadei, 6 L. dumoffii, 4 L. longbeachae, and one each of L. bozemanii, L. hackeliae, L. wadsworthii, and L. maceachernii. Geometric mean MICs microgram/ml were 0.56 for LO, 0.50 for CI, and 0.25 for ER. Ninety percent MICs were 1.0 for LO and CI, and 0.5 for ER. All Legionella strains except one (L. hackeliae) were inhibited by 1.0 microgram/ml of LO or CI; this strain had an Er MIC of 1.0 microgram/ml and was inhibited by 2.0 micrograms/ml of LO or CI. Control strains of Eschershia coli and Staphylococcus aureus were also tested on both BCYEa and Mueller-Hinton agar (MHA) to determine BCYEa-mediated inhibition of the antimicrobials. All three antimicrobials were inactivated in varying degrees by BCYEa. BCYEa:MHA MICs of the S. aureus control strain were 4:1 for LO and ER, and greater than 4:1 for CI. BCYEa: MHA MICs of the E. coli control strain were 4:1 for LO and CI, and unmeasurable for ER. Both LO and CI have good in vitro activity against legionella, probably greater than that measured in this study because of antimicrobial inactivation by BCYEa. Since LO is concentrated by phagocytic cells, like ER and CI, it is likely that it will be effective in the treatment of Legionnaires' disease.
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PMID:In vitro activity of lomefloxacin (NY-198 or SC 47111), ciprofloxacin, and erythromycin against 100 clinical Legionella strains. 279 5

Keto acids and reduced-oxygen-scavenging enzymes were examined for their roles in supporting the growth of Legionella species and for their potential reactions between the chemical components of the media. When grown in an experimental ACES (2-[(2-amino-2-oxoethyl)-amino] ethanesulfonic acid)-buffered chemically defined (ABCD) broth, the presence of keto acids shortened the lag periods, increased the rates of growth, and gave maximum cell yields. In addition, keto acids affected the specific activities of reduced-oxygen-scavenging enzymes determined during growth. The specific activities of superoxide dismutase of Legionella pneumophila (Knoxville) and L. dumoffii (TEX-KL) were increased three- to eightfold, while that of L. bozemanii (WIGA) was not affected. All strains appeared to be equally sensitive to the effects of superoxide anion (O2-) generated by light-activated riboflavin, and all were equally protected by the presence of keto acids in the ABCD broth. Production of trace amounts of acetate and succinate in pyruvate- and alpha-ketoglutarate-containing media exposed to light suggested that hydrogen peroxide was formed. Pyruvate and alpha-ketoglutarate were products of growth on amino acids, and there was no quantitative evidence that these keto acids were metabolized when they were added to the medium. The rate of cysteine oxidation in ABCD broth was increased by the presence of ferric ion or by exposure to light or by both, and keto acids reduced the rate of this oxidation. ACES buffer was a substrate for the production of O2- in the presence of light, and the combined addition of Fe2+ ions, cysteine, and either keto acid to the medium strongly inhibited the production of O2-. Thus, keto acids inhibited the rate of cysteine oxidation, they stimulated rapid growth by an unknown process, and, in combination with added Fe2+ ions and cysteine, they reversed the toxic effects of light by inhibiting O2- production.
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PMID:Role of keto acids and reduced-oxygen-scavenging enzymes in the growth of Legionella species. 300 29

A study was conducted to determine the bactericidal effects of ozone and hydrogen peroxide relative to that of free chlorine on Legionella pneumophila serogroup 1. In laboratory batch-type experiments, organisms seeded at various densities were exposed to different concentrations of these biocides in demand-free buffers. Bactericidal effects were measured by determining the ability of L. pneumophila to grow on buffered charcoal-yeast extract agar supplemented with alpha-ketoglutarate. Ozone was the most potent of the three biocides, with a greater than 99% kill of L. pneumophila occurring during a 5-min exposure to 0.10 to 0.30 micrograms of O3 per ml. The bactericidal action of O3 was not markedly affected by changes in pH or temperature. Concentrations of 0.30 and 0.40 micrograms of free chlorine per ml killed 99% of the L. pneumophila after 30- and 5-min exposures, respectively. A 30-min exposure to 1,000 micrograms of H2O2 per ml was required to effect a 99% reduction of the viable L. pneumophila population. However, no viable L. pneumophila could be detected after a 24-h exposure to 100 or 300 micrograms of H2O2 per ml. Attempts were made to correlate the biocidal effects of O3 and H2O2 with the oxidation of L. pneumophila fatty acids. These tests indicated that certain biocidal concentrations of O3 and H2O2 resulted in a loss or severe reduction of L. pneumophila unsaturated fatty acids.
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PMID:Effects of three oxidizing biocides on Legionella pneumophila serogroup 1. 337 92

Blood was cultured from guinea pigs with experimental Legionella pneumophila serogroup 1 pneumonia, using four different methods. A 0.03-ml amount was spread onto each of several plates of buffered charcoal-yeast extract supplemented with alpha-ketoglutarate (BCYE) (direct plate); 1.5 ml each was inoculated into a BCYE agar-yeast extract broth bottle (biphasic), a pediatric Isolator tube (E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.), and a glass tube containing 0.025% sodium polyanethanolsulfonate. Blood processed in the Isolator tube was plated on BCYE, as was the buffy coat blood fraction, which was obtained by centrifugation of the tube containing sodium polyanethanolsulfonate and blood. Observations were made of the number of positive cultures, the time to detection of positive cultures, and the absolute bacterial concentrations. Each system was equally sensitive in detecting bacteremia. The biphasic method required 5 days for cultures to become positive, whereas the other systems required 2 to 3 days to detect all positive cultures (P = 1.3 X 10(-5) by Friedman group statistic, and P less than 10(-5) for comparison of the biphasic and other methods). The direct plating method demonstrated the best quantitative recovery of L. pneumophila in comparison to the other methods tested (P = 2.0 X 10(-5) by analysis of variance group statistic and P less than 0.05 for comparison between each of the methods). Quantitative recovery by the Isolator method was intermediate between the direct plating and buffy coat methods. The biphasic and Isolator blood culture methods performed poorly in comparison to the other methods, indicating the need for caution in choosing blood culture methods for Legionella isolation.
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PMID:Comparison of blood culture methods for recovery of Legionella pneumophila from the blood of guinea pigs with experimental infection. 357 79


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