David L. Tison

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Bacteria were concentrated 500-fold from 20-liter water samples collected from 67 different lakes and rivers in the United States. The data suggest that Legionella pneumophila is part of the natural aquatic environment and that the bacterium is capable of surviving extreme ranges of environmental conditions. The data further demonstrate the effectiveness of(More)
Illnesses of undiagnosed etiology among researchers exposed to lakes and streams in the Mt. St. Helens blast zone after the 18 May 1980 eruption prompted us to determine the occurrence and potential virulence ofLegionella (Legionnaries' disease bacteria) in aquatic habitats near Mt. St. Helens during the summers of 1981 and 1982. Concentrations ofL.(More)
Clinical and nonclinical isolates of the lactose-positive Vibrio vulnificus were compared with Vibrio strains isolated from lesions on eels (Anguilla japonica) cultured commercially in Japan. Strains were compared phenotypically and antigenically, for pathogenicity to mice and eels, and for genetic relatedness. The strains isolated from diseased eels(More)
Water, sediment, and shellfish from three Oregon estuaries were cultured for pathogenic Vibrio species. Non-O1 serovars of V. cholerae were the most common pathogenic Vibrio species recovered. Non-O1 V. cholerae were isolated from all three estuaries sampled, covering an area of about 170 miles along the Oregon coast. Non-O1 V. cholerae were isolated from(More)
Algal mat communities growing in thermal effluents of production nuclear reactors at the Savannah River Plant, near Aiken, SC, are exposed to large temperature fluctuations resulting from reactor operations. Rates of primary production and species composition were monitored at 4 sites along a thermal gradient in a trough microcosm to determine how these(More)
A comparative evaluation was done to test the accuracy of the Cathra Repliscan II agar dilution system (Diagnostic Equipment, Inc., St. Paul, Minn.), the AutoMicrobic system with Gram-Negative General Susceptibility-Plus Card (Vitek Systems, Inc., Hazelwood, Mo.), and the Micro-Media Fox Panel micro broth dilution system (Micro-Media Systems, Inc., San(More)
Environmental isolates of lactose-positiveVibrio vulnificus from different geographic areas were compared with clinical strains ofV. vulnificus on the basis of their phenotypic traits, virulence, DNA base composition, and DNA-DNA reasociation. EnvironmentalV. vulnificus strains were phenotypically indistinguishable from clinical isolates. These strains had(More)
The incidence and density of Legionella spp. in raw water, water at various stages of treatment, and in potable distribution water were determined by direct immunofluorescence. The number of cells reacting with Legionella-specific fluorescent antibody conjugates in raw waters ranged from about 10(4) to 10(5) cells/liter, whereas the concentrations of(More)