Efficiency of Virus Recovery in Water: Effect of Inorganic and Organic Chemicals

Tchorsh²,

Marva³

1987

Methods for the detection of viable rotaviruses and rotavirus antigen in water were developed and compared. The methods included laboratory-developed enzyme-linked immunosorbent assays (ELISAs) with chromogenic and luminescent substrates, commercial Rotazyme and Enzygnost ELISAs, and an indirect immunofluorescent assay. Of the methods tested, the immunofluorescent assay and the Enzygnost ELISA were the most sensitive for the simian rotavirus SA-li. All of the methods were positive for human rotavirus from clinical specimens. Seeded SA-li rotavirus was concentrated from water by adsorption to and elution from Zeta Plus ifiters followed by organic flocculation. Interference with the assays by components of the wastewater concentrates was minimal for the ELISAs, although the undiluted organic flocs were cytotoxic for the immunofluorescent assay. A survey of Jerusalem wastewater was carried out over the course of 1 year, and samples were assayed for rotaviruses and enteroviruses. Although enteroviruses were found in almost all of the samples, all samples were negative for rotaviruses. The concentration of rotaviruses in the wastewater was thus below the detection limit of the methods used.

Section: Methodsmentioning

confidence: 99%

Comparison of methods for rotavirus detection in water and results of a survey of Jerusalem wastewater

Tchorsh²,

Marva³

1987

“…Virus and virus assay. Poliovirus type I (Brunhilde strain) was grown and titrated by plaque assay on BGM (African green monkey kidney) cells as described (5).…”

Section: Methodsmentioning

confidence: 99%

“…Hula Valley peat (the kind gift of R. Ikan and P. Ioselis) were prepared as previously described (5,6). Relative concentrations of the materials were determined by measuring the A280 in a Varian Techtron Spectrophotometer at pH 7.0.…”

Section: Methodsmentioning

confidence: 99%

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Effects of humic materials on virus recovery from water

Catalano-Sherman²

1985

Humic and fulvic acids were tested for their ability to interfere with virus recovery by microporous filters. Two electropositively charged types of filter (Seitz S and Zeta Plus 60S) were used to concentrate poliovirus in the presence of humic materials. Humic acid inhibited virus adsorption, but even at the highest humic acid concentrations tested (200 mg/liter), 30 to 40% of the virus was recovered by the filters. Fulvic acid, tested with Zeta Plus filters, did not affect virus recovery. For comparison, two electronegatively charged filter types were tested (Cox and Balston). These two types of filter were more sensitive to interference at lower concentrations of humic acid than the more positively charged filters. With Balston filters, at humic acid concentrations above 10 mg/liter, most of the virus was recovered in the filtrate. Fulvic acid, tested with Balston filters, did not interfere with virus recovery. With the electropositively charged filters, the humic materials adsorbed efficiently, even at high input concentrations. Interference with virus adsorption occurred at humic acid concentrations which were below the level of saturation of the filters. In addition, in high-volume experiments, humic acid led to premature blockage of the filters. The efficiency of virus recovery by a second concentration step, organic flocculation of the filter eluate, was tested. For all the filter types tested, this procedure was not affected by the presence of humic or fulvic acid in the input water.

“…The two types of organic acids are generally separated on the basis of their differential solubility in acid, since the fulvic acids are more acid soluble than the humic acids. The major functional groups in both types of acids are similar, although their relative abundance may vary (6,16,25,28 Soluble humic materials have been shown to interfere with virus recovery from water by both positively (11,24) and negatively (7,11,12,24) charged microporous filters. The effects of the humic materials on virus recovery were different for different filter types and sources of humic substances.…”

mentioning

confidence: 99%

Humic acid interference with virus recovery by electropositive microporous filters

Catalano-Sherman²

1986

The effects of humic acid on poliovirus type 1 recovery from water by Zeta Plus 60S filters were investigated. The humic acid interfered by preventing virus adsorption to the filters, and the interference increased as a function of the amount of humic acid filtered. Humic acid decreased virus adsorption when filtered before the virus, but did not elute virus which had adsorbed to the filters. The effects on virus recovery were not due to alterations in virus titer or neutralizability. The addition of AlCl3, which improved virus recovery by electronegative filters in the presence of humic acid, did not aid in overall virus recovery by the Zeta Plus filters in the presence or absence of humic acid. However, the salt and humic acid in combination improved virus adsorption and concurrently reduced virus elution efficiency. The addition of NaH2PO4 had no direct effect on virus recovery and did not alter the effect of humic acid. In an attempt to identify the components of humic acid responsible for the interference, humic materials were fractionated by size by using Sephadex gel chromatography and dialysis, and the fractions were tested for interfering activity. Interference was not associated with specific size fractions of the humic materials.