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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

A chemically defined medium containing 21 amino acids and inorganic salts was developed which supported the growth of four isolates of Legionnaires disease bacterium (Legionella pneumophila). Growth in liquid defined medium at 37 degrees C with shaking approximated the generation time and growth kinetics observed for growth in complex media. After a 3-h lag, the culture grew exponentially with a generation time of 6 h and reached a maximum optical density of 230 Klett units (170 Klett units corrected for pigment). A soluble brown pigment was first observed as the culture entered late exponential to early stationary phase of growth. Morphologically, L. pneumophila grew in the liquid defined medium with extensive filamentation and numerous intracellular lipid granuoles. L-Serine, L-methionine, and L-cysteine were required for optimum growth. The latter amino acid could be replaced by L-cystine or reduced glutathione but not by D-cysteine, thiomalate, thioglycollate, or 2-mercaptoethanol. Ferric iron was needed for maximum growth, but supplemental iron was not an essential growth requirement. Carbohydrates (i.e., glucose) or organic acids did not stimulate growth. In fact, pyruvate, acetate, and citrate all gave varying degrees of inhibition (69, 37, and 0% of control growth, respectively).
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PMID:Growth of Legionnaires disease bacterium (Legionella pneumophila) in chemically defined medium. 50 Jul 95

Five 14C-labelled macrolide antibiotics (erythromycin, josamycin, clarithromycin (TE-031), rokitamycin and roxithromycin) were studied for their transport into human polymorphonuclear leucocytes. Intracellular/extracellular concentration ratios (transport ratios) of these macrolides were quite high: erythromycin, 6.6; josamycin, 15.5; clarithromycin, 16.4; rokitamycin, 30.5; and roxithromycin, 21.9. When polymorphonuclear leucocytes were pre-treated with formaldehyde or incubated at 4 degrees C, or at low pH, transport ratios were reduced. When extracellular macrolide was removed, intracellular macrolide concentrations became as low as 30% of the pre-wash concentrations in 5 min. KF lowered the transport ratios of josamycin and rokitamycin in particular and NaCN reduced the transport ratios of erythromycin and josamycin strikingly. Ouabain slightly lowered transport ratios of all the antibiotics tested except roxithromycin, and 2, 4-dinitrophenol decreased the transport ratio of clarithromycin markedly. The addition of various amino acids or hexose did not inhibit the transfer. Adenosine, however, inhibited the transfer of these antibiotics except erythromycin and lowered transport ratios by 83 to 92%. Puromycin reduced transport ratios of the same antibiotics by 59 to 95%. With polymorphonuclear leucocytes that had phagocytosed Legionella pneumophila serogroup 1, transport ratios of all five drugs tended to decrease. However, when Staphylococcus aureus ATCC 25923 or opsonized zymosan was phagocytosed, transport ratios for macrolides, except for roxithromycin, increased.
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PMID:Penetration of macrolides into human polymorphonuclear leucocytes. 259 96

Lipopolysaccharide isolated from Legionella pneumophila (Phil. 1) was examined for chemical composition. The polysaccharide split off by mild acid hydrolysis contained rhamnose, mannose, glucose, quinovosamine, glucosamine and 2-keto-3-deoxyoctonate, in molar proportions 1.6:1.8:1.0:1.5:4.1:2.7. Heptoses were absent and glucose was probably mainly phosphorylated. The carbohydrate backbone of the lipid A part consisted of glucosamine, quinovosamine and glycerol, in the molar ratios 3.9:1.0:3.4, with glycerol as a phosphorylated moiety. A complex fatty acid substitution pattern comprising eight O-ester-linked, exclusively nonhydroxylated acids, and nineteen amide-linked, exclusively 3-hydroxylated acids was revealed. Both straight- and branched (iso and anteiso) carbon chains occurred. The major hydroxy fatty acid was 3-hydroxy-12-methyltridecanoic acid and six others were of a chain-length above 20 carbon atoms, with 3-hydroxy-20-methyldocosanoic acid as the longest. Two dihydroxy fatty acids, 2,3-dihydroxy-12-methyltridecanoic and 2,3-dihydroxytetradecanoic acids, were also detected. These results suggest that L. pneumophila contains a rather complex and unusual lipopolysaccharide structure of considerable biological and chemotaxonomic interest.
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PMID:Chemical composition of a lipopolysaccharide from Legionella pneumophila. 261 May 84

AT-4140, 5-amino-1-cyclopropyl-6,8-difluoro-1,4-dihydro-7-(cis-3,5- dimethyl-1-piperazinyl)-4-oxoquinoline-3-carboxylic acid, showed broad and potent antibacterial activity. Its MICs for 90% of the strains tested were 0.1 to 0.78 micrograms/ml against gram-positive organisms, such as members of the genera Staphylococcus, Streptococcus, and Enterococcus, and 0.0125 to 1.56 micrograms/ml against gram-negative organisms, such as members of the family Enterobacteriaceae and the genera Pseudomonas, Branhamella, Campylobacter, Haemophilus, and Neisseria. Its MICs were 0.025 to 0.78 micrograms/ml against glucose nonfermenters, such as members of the genera Xanthomonas, Acinetobacter, Alcaligenes, Moraxella, Flavobacterium, and Brucella; 0.2 to 0.78 micrograms/ml against anaerobes, such as Clostridium perfringens and Bacteroides fragilis; 0.0125 to 0.05 micrograms/ml against Legionella spp.; 0.0125 to 0.2 micrograms/ml against Mycoplasma spp.; 0.031 to 0.063 micrograms/ml against Chlamydia spp.; and 0.1 to 0.3 micrograms/ml against Mycobacterium spp. The potencies of AT-4140 against gram-negative organisms were comparable to those of ciprofloxacin and higher than those of ofloxacin, enoxacin, and norfloxacin. The potencies of AT-4140 against gram-positive organisms, glucose nonfermenters, anaerobes, Mycoplasma spp., Chlamydia spp., and Mycobacterium spp. were generally higher than those of the quinolones with which AT-4140 was compared. AT-4140 showed good oral efficacy against systemic infections with Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Escherichia coli, and Pseudomonas aeruginosa in mice. Its efficacy was better when a daily dose was given once than when it was given in two doses. Good efficacies of the orally administered drug were also observed in pulmonary, dermal, and urinary tract infection models in mice. The in vivo efficacies of AT-4140 were equal to or better than those of ciprofloxacin, ofloxacin, enoxacin, and norfloxacin.
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PMID:In vitro and in vivo antibacterial activities of AT-4140, a new broad-spectrum quinolone. 280 44

The antibacterial activity of fleroxacin (Ro 23-6240, AM-833), a new 6-fluoroquinolone, was determined against 149 strains of enteropathogenic bacteria (17 species) and 191 strains (28 species) of glucose non-fermentative Gram-negative rods (excluding Pseudomonas aeruginosa), and against 15 strains of Legionella pneumophila. The cumulative susceptibility of these groups of bacteria to Ro 23-6240 at the 2 mg/l level were 99.2%, 80.1 and 100% of tested strains, respectively.
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PMID:Fleroxacin (Ro 23-6240): activity in vitro against 355 enteropathogenic and non-fermentative gram-negative bacilli and Legionella pneumophila. 311 53

The in vitro activity of the free acid of cefetamet pivoxil (Ro 15-8075) was tested against 355 clinical isolates, namely enteropathogenic bacteria, glucose non-fermentative gram-negative rods (excluding Pseudomonas aeruginosa) and Legionella pneumophila. Ceftriaxone was included in the study as reference compound. Although the free acid of the orally active cephalosporin was generally weaker than ceftriaxone, it inhibited 88.2% and 94.5% of Enterobacteriaceae and Vibrionaceae at a concentration of 4 mg/l and 8 mg/l or less, respectively. Campylobacter jejuni proved resistant to both compounds. The activity of the new compound against glucose non-fermentative gram-negative rods was generally insufficient to be of promise for broad clinical use. Although the compound was at least twofold more active than ceftriaxone against Pseudomonas acidovorans, Pseudomonas alcaligenes and Pseudomonas cepacia, the former was at least two dilution steps less active than the latter against 14 species of the other less common glucose non-fermentative organisms.
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PMID:Cefetamet pivoxil: bacteriostatic and bactericidal activity of the free acid against 355 gram-negative rods. 340 40

The utilization of amino acids and other compounds as carbon and energy sources by Legionella pneumophila was examined. Based on the stimulation of oxygen consumption in washed-cell suspensions, glutamate, serine, threonine, and tyrosine were the only amino acids which were utilized as energy sources. Other stimulators of oxygen uptake were lactate, pyruvate, acetate, fumarate, and succinate. Citrate was a good stimulator only when the bacteria were grown in the presence of the substrate. Radiolabeling studies showed that [14C]glutamate was rapidly metabolized, with the label distributed evenly in all cell fractions. [14C]pyruvate and [14C]acetate were incorporated into the lipid-containing cell fraction, whereas glucose and glycerol were found in both the lipid- and polysaccharide-containing cell fractions. Radiorespirometry of differentially labeled [14C]glucose indicated that this compound was metabolized primarily by the pentose phosphate and Entner-Doudoroff pathways rather than by the glycolytic pathway.
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PMID:Intermediary metabolism in Legionella pneumophila: utilization of amino acids and other compounds as energy sources. 613 45

Six strains of a new species, Legionella sainthelensi, were isolated from freshwater in areas affected by the volcanic eruptions of Mt. St. Helens in the state of Washington. Strains of L. sainthelensi are culturally and biochemically similar to other legionellae. They grow on buffered charcoal yeast agar but not on media that lack cysteine. They are gram-negative, nonsporeforming, motile rods that are positive in reactions for catalase, oxidase, gelatin liquefaction, and beta-lactamase. They are negative in reactions for urease, hydrolysis of hippurate, reduction of nitrates, fermentation of glucose, and blue-white autofluorescence. Their cell wall fatty acid composition is qualitatively similar to those of other legionellae, with 50 to 62% branched-chain fatty acids. They contain the isobranched-chain 14- and 16-carbon acids and anteisobranched-chain 15- and 17-carbon acids and relatively large amounts of straight-chain 16-carbon acid. All strains of L. sainthelensi contain approximately equal amounts of ubiquinones Q9, Q10, Q11, and Q12, a pattern similar to those of Legionella bozemanii, Legionella dumoffi, and Legionella longbeachae. Serological cross-reactions were observed between L. sainthelensi, both serogroups of L. longbeachae, and Legionella oakridgensis. Three strains of L. sainthelensi were greater than 90% related by DNA hybridization. The type strain of L. sainthelensi, Mt. St. Helens 4, was 36% related to the type strain of L. longbeachae and 3 to 14% related to the other nine described Legionella species.
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PMID:Legionella sainthelensi: a new species of Legionella isolated from water near Mt. St. Helens. 671 10

The effect of Legionella pneumophila toxin on selected functions of human polymorphonuclear leukocytes was investigated. Amounts of L. pneumophila toxin that had no effect on leukocyte viability or phagocytosis significantly decreased hexose monophosphate shunt activity and O2 consumption during phagocytosis and bacterial iodination and killing in a dose-dependent fashion. The mechanism of action of this toxin appears to be unique among bacterial products thus far studied.
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PMID:The effects of Legionella pneumophila toxin on oxidative processes and bacterial killing of human polymorphonuclear leukocytes. 705 Feb 55


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