The Effects Of Various Enzymatic And Chemical Treatments On The Infectivity Of Aleutian Disease Virus Of Mink

Abstract

Aleutian disease virus (ADV), a parvovirus, was treated with the enzymes trypsin, alpha-chymotrypsin (CT), pronase, deoxyribonuclease (DNase), and ribonuclease (RNase) by incubation at 37C for 60 min. Effects of enzyme treatment on the infectivity of ADV were determined by direct immunofluorescent assay, which showed the only significant drop in titer, about 2 logQ, from treatment with pronase, trypsin, and CT. A change of over 1 log-,g was found to be significant using this assay. A time course of digestion by trypsin and CT was followed through liquid scintillation counting (LSC) of S methionine-labeled Crandall feline kidney cells (CRFKs), both ADV-infected and ADV-free. A time course of ADV digestion by trypsin and x.CT was also followed by direct immunofluorescence assay. Activity of the enzymes on the ADV is most pronounced in the first 10 min of incubation. The results of this experiment concur with those obtained by Burger (8) and Eklund (13) using an in vivo assay method.