Airborne phages resistance to temperature and humidity

The use of aerosolized bacteriophages as surrogates to hazardous viruses could simplify and accelerate the discovery of links between viral components and their persistence in the airborne state under diverse environmental conditions. In this study, four structurally distinct lytic phages, MS2 (ssRNA), F6 (dsRNA), FX174 (ssDNA) and PR772 (dsDNA), were nebulised into a rotating chamber and exposed to various levels of relative humidity (RH) and temperature as well as to germicidal ultraviolet radiations. The aerosolized viral particles were allowed to remain airborne for up to fourteen hours before being sampled for analysis by plaque assays and quantitative PCR. Phages F6 and MS2 were most resistant at low levels of relative humidity whilst FX174 was more resistant at 80% RH. Phage F6 lost its infectivity immediately after exposure to 30°C and 80% RH. The infectivity of all tested phages rapidly declined as a function of the exposure time to UV-C radiations, phage MS2 being the most resistant. Taken altogether, our data indicate that these aerosolized phages behave differently under various environmental conditions and highlight the necessity of carefully selecting viral simulants in bioaerosols studies