PubMed Health⌕ Search

Biomedical subjects

N D Seeley

Publications and source records attributed to N D Seeley.

7 recordsLinked to original sources
PubMed1982

Isolation of a bisegmented double-stranded RNA virus from Thirlmere reservoir.

A novel bisegmented double-stranded RNA virus has been isolated from water processed from Thirlmere reservoir. The virus is icosahedral, 58 nm in diam., has a buoyant density of 1.32 g/ml in CsCl, has an S value of 400 and a RNA/protein ratio of 0.087. The two linear segments of RNA have approx. mol. wt. of 2.26 X 10(6) and 2.09 X 10(6). The virus contains six polypeptides. The virus was isolated in Drosophila melanogaster cells and fails to replicate in other insect, amphibian, avian, piscine, mammalian and plant cells tested. The virus is biochemically different from infectious pancreatic necrosis virus (IPNV) and Drosophila X virus (DXV). The virus is also serologically unrelated to IPNV (strain Sp) and another invertebrate pathogenic virus, Tellina virus 1. The virus shares common antigens with DXV but is not completely identical.

Animals↗
PubMed1982

Methods for studying aquatic bacteriophage ecology.

Methods are described for enumerating the different kinds of bacteriophage present in virus concentrates prepared from 120 liters of water. Although developed specifically for use with coliphages, they should be applicable to viruses infecting other hosts. These methods involve mixed indicators, equilibrium buoyant-density centrifugation, use of enzymes or inhibitors or both, and specific hybridization probes, either alone or in combination. With these methods, it was possible to specifically enumerate filamentous and isometric male-specific (F-specific) phages, the different classes of P-group plasmid-specific phages, phiX174-like phages, and lambda-like phages. Some applications of these methods, including measurement of virus inactivation in the environment and the extent of fecal pollution, are discussed.

Journal Article↗
PubMed1981

A portable device for the rapid concentration of viruses from large volumes of natural freshwater.

A portable device for the rapid concentration of viruses from natural freshwaters described and its performance in field use is evaluated. The system handled up to 500 litres of water in less than 90 min at a cost of only 2 pounds per sample. Where the samples contained sufficient bacteriophages for detection by direct plating the apparent phage recoveries were greater than 75%. Plant and animal viruses were also concentrated from waters with this system.

Bacteriophages↗
PubMed1980

Rapid concentration of bacteriophages from large volumes of freshwater: evaluation of positively charged, microporous filters.

Microporous, positively charged Zeta Plus 60 S filters were evaluated for bacteriophage recovery from large volumes of natural water. A variety of phages adsorbed efficiently to the filter medium at water pH levels below neutrality, but adsorption was reduced above pH 7. Adsorbed phages were easily eluted with an arginine/1% beef extract solution, pH 9.0. A concentration procedure suitable for the field isolation of bacteriophages from large volumes of river water was devised. The procedure involves, (1) prefiltration through 10" cartridge depth filters, (2) adjustment of water pH to pH 5.5--6.0, (3) adsorption of the phages on to Zeta Plus 60 S filters, (4) elution of bound phage in a small volume of eluent, (5) secondary concentration by ultrafiltration of the resulting eluates. Using this procedure, bacteriophages in 65 1 of river water was concentrated to 35 ml with recoveries in the range 50--60%.

Adsorption↗