Respective stability of rotavirus and coronavirus in bovine milk

Abstract

Bovine rotavirus and coronavirus (1.5 × 104 PFU/ml) were inoculated into raw cow whole milk, acid whey or a range of heat-treated milks and wheys. Raw milk inhibited growth of both viruses, but 1.3-1.4 and 1.2-2.0 × 104 PFU/ml rotavirus and coronavirus resp. were recovered from heat-treated milks and wheys. Incubation at 4, 20, 63 or 72°C, with 5 or 33% NaCl, at pH 4.6, 5.4 or 6.3 or with calf rennet at 33°C had negligible effect on viral growth in previously heat-treated milk. Secondary viral contamination of French cheeses, such as Camembert, made with raw milk appears to be possible.