Pseudomonas gessardii sp. nov. and Pseudomonas migulae sp. nov., two new species isolated from natural mineral waters.
Twenty-five non-identified fluorescent Pseudomonas strains isolated from natural mineral waters were previously clustered into three phenotypic subclusters, XIIIb, XVa and XVc. These strains were characterized genotypically in the present study. DNA-DNA hybridization results and DNA base composition analysis revealed that these strains were members of two new species, for which the names Pseudomonas gessardii sp. nov. (type strain CIP 105469T) and Pseudomonas migulae sp. nov. (type strain CIP 105470T) are proposed. P. gessardii included 13 strains from phenotypic subclusters XVa and XVc. P. migulae included 10 strains from phenotypic subcluster XIIIb. The levels of DNA-DNA relatedness ranged from 71 to 100% for P. gessardii and from 74 to 100% for P. migulae. The G + C content of the DNA of each type strain was 58 mol%. DNA similarity levels, measured with 67 reference strains of Pseudomonas species, were below 55%, with delta Tm values of 13 degrees C or more. The two new species presented basic morphological characteristics common to all pseudomonads. Various phenotypic features were found to differentiate them: P. gessardii strains utilized L-arabitol, myo-inositol, adonitol, xylitol and meso-erythritol as carbon sources, whereas P. migulae strains assimilated L-arabinose, D-xylose, D-saccharate, meso-tartrate, tricarballylate, D-glucuronate, D-galacturonate, phenylacetate and histamine. The complete 16S rRNA sequences of each type strain were determined and compared with those of the type strains of Pseudomonas species. Finally, a phylogenetic tree was inferred from sequence analysis and demonstrated that the two new species fell into the 'Pseudomonas fluorescens intrageneric cluster'. To date, their clinical significance is unknown. (+info)
Effect of beer consumption on plasma magnesium: randomized comparison with mineral water.
Moderate consumption of ethanol lowers mortality from coronary artery disease, and one of the possible mechanisms is an antiarrhythmic action. We therefore investigated the effect of a small daily dose of beer on plasma electrolytes. 52 men who seldom drank alcohol, clinically stable more than one year after coronary bypass surgery, were randomized to drink either 330 mL beer (containing about 20 g ethanol) or mineral water with similar potassium, magnesium, calcium and sodium content daily for 30 days. Plasma electrolytes and liver function indices, and also heart rate, blood pressure and weight, were measured before and after the trial period. The only significant before-and-after difference was in the group consuming beer, whose plasma magnesium rose from 0.89 (SD 0.01) to 0.98 (SD 0.02) mmol/L (P < 0.0025). This level of beer consumption did no obvious harm to liver function and its possibly beneficial effect on plasma magnesium deserves further investigation. (+info)
Mineral water as a source of dietary calcium: acute effects on parathyroid function and bone resorption in young men.
BACKGROUND: Calcium is a major component of mineralized tissues and is required for normal growth and maintenance of bone. Epidemiologic studies showed that a large percentage of the population fails to meet the currently recommended guidelines for optimal calcium intake. OBJECTIVE: The present study was designed to determine whether high-calcium mineral water is an efficient additional source of dietary calcium. DESIGN: Twelve healthy young men (mean +/- SD age: 21.1 +/- 1.2 y) ingested in a randomized order either 0.5 L of a mineral water containing 344 mg Ca/L or 0.5 L of a mineral water with a very low concentration of calcium (<10 mg/L) as a control. Blood samples were drawn before and 1, 2, 3, and 4 h after intake of the water. Urine was collected for 2 h before and every 2 h for 4 h after ingestion of the water. Serum concentrations of intact parathyroid hormone (iPTH) and serum concentrations and urinary excretion of a recently developed biochemical marker of bone resorption, type 1 collagen cross-linked C-telopeptide (CTx), were measured. RESULTS: Serum iPTH was significantly (P < 0.002) lower after ingestion of high-calcium water than after ingestion of the control. There was a significant (P = 0.01) progressive decrease in urinary CTx after ingestion of the high-calcium water, whereas after ingestion of low-calcium water the changes were modest and not significant. The fall in serum CTx concentrations was 34.7% 3 h after ingestion of high-calcium water, compared with 17.6% with the control. The decreases in serum CTx concentrations were significantly (P < 0.05) lower 1, 2, 3, and 4 h after ingestion of high-calcium water than after ingestion of the control. CONCLUSION: The present study showed that one oral intake of water containing a very moderate dose of calcium (172 mg) acutely inhibited iPTH secretion and bone resorption. (+info)
Survey of bottled drinking water available in Manitoba, Canada.
Forty domestic and imported brands of bottled water were purchased in Manitoba, Canada and examined for total dissolved solids (TDS), chloride, sulfate, nitrate-nitrogen, cadmium, lead, copper, and radioactivity. The samples showed great variation in quality, and some exceeded the Canadian Water Quality Guidelines for drinking water for TDS, chloride, and lead. Carbonation, ozonation, and type of packaging were not associated with differences in metal levels, although carbonated samples tended to show higher TDS values. A number of deficiencies were found with respect to product labeling. (+info)
Comparison of the mineral content of tap water and bottled waters.
OBJECTIVES: Because of growing concern that constituents of drinking water may have adverse health effects, consumption of tap water in North America has decreased and consumption of bottled water has increased. Our objectives were to 1) determine whether North American tap water contains clinically important levels of calcium (Ca2+), magnesium (Mg2+), and sodium (Na+) and 2) determine whether differences in mineral content of tap water and commercially available bottled waters are clinically important. DESIGN: We obtained mineral analysis reports from municipal water authorities of 21 major North American cities. Mineral content of tap water was compared with published data regarding commercially available bottled waters and with dietary reference intakes (DRIs). MEASUREMENTS AND MAIN RESULTS: Mineral levels varied among tap water sources in North America and among bottled waters. European bottled waters generally contained higher mineral levels than North American tap water sources and North American bottled waters. For half of the tap water sources we examined, adults may fulfill between 8% and 16% of their Ca2+ DRI and between 6% and 31% of their Mg2+ DRI by drinking 2 liters per day. One liter of most moderate mineralization European bottled waters contained between 20% and 58% of the Ca2+ DRI and between 16% and 41% of the Mg2+ DRI in adults. High mineralization bottled waters often contained up to half of the maximum recommended daily intake of Na+. CONCLUSION: Drinking water sources available to North Americans may contain high levels of Ca2+, Mg2+, and Na+ and may provide clinically important portions of the recommended dietary intake of these minerals. Physicians should encourage patients to check the mineral content of their drinking water, whether tap or bottled, and choose water most appropriate for their needs. (+info)
Dethiosulfovibrio russensis sp. nov., Dethosulfovibrio marinus sp. nov. and Dethosulfovibrio acidaminovorans sp. nov., novel anaerobic, thiosulfate- and sulfur-reducing bacteria isolated from 'Thiodendron' sulfur mats in different saline environments.
Four strains of strictly anaerobic, sulfur- and thiosulfate-reducing bacteria, SR12T, SR13, SR15T and WS100T, were isolated from 'Thiodendron' sulfur mats obtained from different saline environments. All isolates were motile, Gram-negative, non-spore-forming curved rods with pointed or rounded ends. The sizes of cells varied from 0.9 x 3-5 microm for strains SR12T, SR13 and SR15T to 0.9 x 4.8 microm for strain WS100T. All strains could form long spiral filamentous cells up to 70-110 microm during the early stage of growth. All strains were motile by a tumbling movement and possessed lateral flagella arranged at the concave side of cells. Incomplete cross-septa were distinctive features of all strains. Growth occurred at temperatures of 10-40 degrees C with an optimum at 28 degrees C. The pH limits for growth were 5.5 to 8.0, with optimal growth at pH 6.5-7.0. All isolates were obligately anaerobic and slightly halophilic and grew in media containing 0.5-5% NaCl with an optimum at 2% NaCl. All strains were chemoorganoheterotrophic, having a fermentative type of metabolism and utilized proteins, peptides, amino acids and some organic acids, but not sugars, fatty acids or alcohols. Some organic substrates (isoleucine, valine, alanine, glutamate) were utilized only by strain SR12T in the presence of sulfur or thiosulfate. Fermentation of citrate yielded mainly acetate, CO2 and H2. Sulfur and thiosulfate were reduced to hydrogen sulfide during the fermentation of organic substances, which increased cell yields and growth rates. Sulfate, sulfite, fumarate, nitrate, Fe2O3, MnO2, DMSO and elemental selenium were not used as electron acceptors by these strains. The G+C contents of the DNA were 51 mol% for strains SR12T, SR13 and SR15T and 52 mol% for strain WS100T. Based on morphological, physiological and phylogenetic similarities, all four isolates could be assigned to three new species of the genus Dethiosulfovibrio, named Dethiosulfovibrio russensis (type strain DSM 12538T), Dethiosulfovibrio marinus (type strain DSM 12537T) and Dethiosulfovibrio acidaminovorans (type strain DSM 12590T). (+info)
Meal effect on magnesium bioavailability from mineral water in healthy women.
BACKGROUND: Magnesium intakes in many industrialized countries are below recommended daily allowances. Magnesium-rich mineral water may contribute to coverage of magnesium requirements by providing significant amounts of natural, energy-free, bioavailable magnesium. OBJECTIVE: The objectives were to determine magnesium bioavailability from magnesium-rich (110 mg/L) mineral water in healthy subjects when consumed alone and to evaluate the effect of simultaneous meal consumption. DESIGN: Magnesium bioavailability was measured in 10 healthy women with the use of a crossover design. Stable magnesium isotopes ((25)Mg and (26)Mg) were administered orally with mineral water, which was consumed with or without a meal. Apparent magnesium absorption was determined by fecal monitoring, and magnesium retention was determined from urinary excretion of magnesium isotopes. RESULTS: The mean (+/-SD) magnesium absorption from mineral water consumed alone was 45.7 +/- 4.6% (range: 40.2-55.5%) and was significantly greater (P = 0.0001) when it was consumed with a meal (52.3 +/- 3.9%; 46.2-60.2%), a relative difference of 14.4%. Magnesium retention also was significantly greater (P = 0.0004) when mineral water was consumed with a meal (41.5 +/- 4.2%; 35.2-50.6%) than when consumed alone (37.4 +/- 4.0%; 33.1-47.0%), a relative difference of 11.0%. CONCLUSIONS: In healthy young women, approximately 50% of the magnesium from magnesium-rich mineral water was absorbed when consumed alone. Magnesium bioavailability from mineral water is enhanced when the water is consumed with a meal, perhaps because of a slower gastrointestinal transit time, the presence of digestion products from the meal, or both. Regular consumption of magnesium-rich mineral water could make a valuable contribution to magnesium requirements. (+info)
Natural genetic transformation of clinical isolates of Escherichia coli in urine and water.
Transfer of plasmid-borne antibiotic resistance genes in Escherichia coli wild-type strains is possible by transformation under naturally occurring conditions in oligotrophic, aquatic environments containing physiologic concentrations of calcium. In contrast, transformation is suppressed in nitrogen-rich body fluids like urine, a common habitat of uropathogenic strains. Current knowledge indicates that transformation of these E. coli wild-type strains is of no relevance for the acquisition of resistance in this clinically important environment. (+info)