Concentration of enteric viruses from water with lettuce extract.

Applied microbiology 11/1974; 28(4):717-9.
Source: PubMed

ABSTRACT A method for recovering enteroviruses, adenovirus, and reovirus from water with lettuce extract is described. Lettuce extract at pH 8.5 was added to the sample and the pH was reduced stepwise with hydrochloric acid to 4.0 to 4.5. The flocculent lettuce-extract particles, and adsorbed virus, were readily removed from solution by low-speed centrifugation. Electron microscopy suggests that, under conditions suitable for adsorption, virus particles are coated with the lettuce-extract colloid.

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    ABSTRACT: The efficiency of a Millitube MF cartridge filter, a membrane filter, for recovery of poliovirus from 100-gal volumes of both fresh (tap) and estuarine water was determined. In the high multiplicity of virus input-output experiments, recovery of 97% or greater of input virus was achieved in both types of water when the final concentration of divalent cation as Mg(2+) was 1,200 mug/ml and the pH was 4.5. Virus was effectively eluted from the membrane cartridge with 5x nutrient broth in 0.05 M carbonate-bicarbonate buffer at pH 9.0. Four elutions of 250 ml each were used. In the low multiplicity of virus input-output experiments under the same cationic and pH conditions, up to 67% of the input virus was recovered when the virus was further concentrated from the eluates by the aqueous polymer two-phase separation technique. The volume reduction was 126,000-190,000 to 1. The use of the combined techniques, i.e., membrane adsorption followed by aqueous polymer two-phase separation, provided a highly sensitive, simple, and remarkably reliable sequential methodology for the quantitative recovery of poliovirus occurring at multiplicities as low as 1 to 2 plaque-forming units per 5 gal of water.
    Applied microbiology 06/1972; 23(5):880-8.
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    ABSTRACT: An improved method for concentrating viruses from large volumes of clean waters is described. It was found that, by acidification, viruses in large volumes of water could be efficiently adsorbed to epoxy-fiber-glass and nitrocellulose filters in the absence of exogenously added salts. Based upon this finding, a modified version of our previously described virus concentration system was developed for virus monitoring of clean waters. In this procedure the water being tested is acidified by injection of N HCl prior to passage through a virus adsorber consisting of a fiber-glass cartridge depth filter and an epoxy-fiber-glass membrane filter in series. The adsorbed viruses are then eluted with a 1-liter volume of pH 11.5 eluent and reconcentrated by adsorption to and elution from a small epoxy-fiber-glass filter series. With this method small quantities of poliovirus in 100-gallon (378.5-liter) volumes of tapwater were concentrated nearly 40,000-fold with an average virus recovery efficiency of 77%.
    Applied microbiology 11/1973; 26(4):529-34.
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    ABSTRACT: Cellulose nitrate membranes were used as one of the adsorbents in concentrating viruses from water. For adsorption to occur, salts were required. With increase in valency of salt, less salt was necessary for enhanced virus adsorption to membranes. Trivalent salts were more effective because they could be used at only 1% the concentration required for divalent salts. Thus, 0.5 mM AlCl(3) was as effective as 50 mM MgCl(2). For testing 500 gal of water, only 0.24 kg of AlCl(3) was required in contrast to 20 kg of MgCl(2). Virus could then be eluted from such membranes, having an area of 486 cm(2), with 250 ml of pH 11.5 buffer. Lowering the pH of the eluate and adding AlCl(3) permitted the virus to be quickly readsorbed on a smaller cellulose membrane, i.e., 4 cm(2). Virus for assay was eluted from the small membrane in 1 ml. This procedure has provided the basis for concentrating minute amounts of virus from large volumes of water.
    Applied microbiology 04/1972; 23(3):476-80.


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