Abstract
Agents of transmissible spongiform encephalopathy (prion) are known to be extremely resistant to physicochemical inactivation procedures such as heat, radiation, chemical disinfectants such as detergents, alcohols, glutaraldehyde, formalin, and so on. Because of its remarkable resistance, it is difficult to inactivate prion. Chemical inactivation seems to be a practical method because it is applicable to large or fixed surfaces and complicated equipment. Here, three epoxides: β-propiolactone, propylene oxide, and glycidol (GLD) were examined of their inactivation ability against scrapie-mouse prion protein (PrPSc) under various conditions of chemical concentration, incubation time, and temperature. Among these chemicals, GLD worked most effectively and degraded PrP into small fragments. As a result of the bioassay, treatment with 3% GLD for 5 hr and 5% GLD for 2, 5 hr or 12 hr at room temperature prolonged the mean incubation time by 44, 30, 110 and 73 days, respectively. From dose-incubation time standard curve, the decrease in infectivity titers were estimated as 103 or more. Therefore, degradation of PrPSc by GLD decreased the scrapie infectivity. It is also suggested that pH and salt concentrations influence the effect of GLD. Although further study is necessary to determine the optimal condition, GLD may be a potential prion disinfectant.
