Adsorption of reovirus to clay minerals: effects of cation-exchange capacity, cation saturation, and surface area

Abstract

The adsorption of reovirus to clay minerals has been reported by several investigators, but the mechanisms defining this association have been studied only minimally. The purpose of this investigation was to elucidate the mechanisms involved with this interaction. More reovirus type 3 was adsorbed, in both distilled and synthetic estuarine water, by low concentrations of montmorillonite than by comparable concentrations of kaolinite containing a mixed complement of cations on the exchange complex. Adsorption to the clays was essentially immediate and was correlated with the cation-exchange capacity of the clays, indicating that adsorption was primarily to negatively charged sites on the clays. Adsorption was greater with low concentrations of clays in estuarine water than in distilled water, as the higher ionic strength of the estuarine water reduced the electrokinetic potential of both clay and virus particles. The addition of cations (as chloride salts) to distilled water enhanced adsorption, with divalent cations being more effective than monovalent cations and 10-2 M resulting in more adsorption than 10-3 M. Potassium ions suppressed reovirus adsorption to montmorillonite,

Effect of kaolinite on the specific infectivity of reovirus

“…2a and b). However, adsorption and binding isotherms and competitive adsorption studies between reovirus, coliphage T1, proteins, and phosphate ions indicated that ad- i~ i~ ~ sorption of the virus occurred primarily to negatively charged edge sites on the clay [19][20][21][22], in agreement with studies that showed that adsorption was correlated with the cation-exchange capacities of two different types of clay minerals (i.e., K1 and M) [17]. Although the apparent adsorption of reovirus to the face of K1 may have been real, as some negative (i.e., cation exchange) sites are present there, it may have been an artifact, as the CPD method was not used in the preparation of Kl-virus complexes for TEM.…”

“…The adsorption of reovirus on K1, either homoionic or containing a natural mixed complement of cations, was primarily the result of protonation of the virus, followed by cation exchange (an electrostatic interaction). Adsorption was reversible, as 3-4 washings with distilled water removed more than 99.9% of the adsorbed virus [17,20]. In contrast, attachment of enteroviruses (including reovirus) to susceptible cells is characterized by an initially reversible, nonspecific electrostatic attachment, followed by nonreversible binding that is probably mediated through a covalent interaction between specific ligands on the virion and on their complementary receptors on the cell [7,23].…”

“…The purification and titration of reovirus type 3, the growth and maintenance of L-929 mouse fibroblast cells, and the preparation of KI containing a natural mixed cation complement were as described previously [17].…”

Antiviral effects on bacteriophages and rotavirus by cranberry juice

“…The cell cultures were grown and maintained in T25 cm 2 vented cell culture flasks in a 5% CO 2 atmosphere at 37 1C. Monolayers were passaged by trypsinization (0.025% trypsin) and seeded at a concentration of approximately 1 Â 10 5 cells/ml (Lipson and Stotzky, 1983;Lipson, 1992). Seed MA-104 tube cultures were obtained from ViroMed Laboratories, Minneapolis, MN.…”

In vitro studies on the use of clay, clay minerals and charcoal to adsorb bovine rotavirus and bovine coronavirus

“…Various clays have also been shown to adsorb and inactivate the thermo-labile (LT) enterotoxins of Escherichia coli and the cholera toxin (CT) enterotoxins of Vibrio cholerae which has been reviewed recently (Ramu et al, 1997). There is also evidence of virus adsorption to clays; the viruses most studied include poliovirus, encephalomyocarditis virus and reovirus (Kelly et al, 1961;Schaub and Sagik, 1975;Taylor et al, 1981;Lipson and Stotzky, 1983;Preston and Farrah, 1988).…”