SENSITIVITY OF SWINE CORONAVIRUS TO ACTION OF DIFFERENT TEMPERATURES

Abstract

Coronavirus infections are currently receiving a lot of attention due to the emergence of the covid-19 pandemic in the world. The search for models with which it is possible to obtain an adequate result to identify the properties of coronaviruses is intensive. For comparison with the results of our experiments, the article also presents data on the duration of preservation of the infectious properties of the SARS-Cov-2 virus by contamination of surfaces made of different materials and at different temperatures.
 We studied the long-term effect on coronavirus, the causative agent of transmissible swine gastroenteritis (TGE), a number of temperatures: + 4ºC, + 25ºC, minus 13ºC, minus 20ºC and thirteen-fold change in temperature, which was in the range of 31-33ºC. It was found that both vaccine and epizootic strains of TGE coronavirus after long-term storage reduce the infectious properties, but when in contact with a sensitive biological system (in vitro) quickly enough (in the case of successive passages in this system) restore them. We proved that the TGE coronavirus during storage for more than two years reduced, but did not lose infectious properties at temperatures minus 13ºC, minus 20ºC, which were restored during subsequent passage in sensitive biological systems in vitro. The same trend was observed for storage of the virus for 8 years at a temperature of + 4ºC. The fastest decrease in coronavirus titer occurred at a temperature of + 25ºC, but more stable under these conditions was the epizootic strain of the virus, which requires attention when working with field isolates of coronavirus.
 The general tendency of animal and human coronaviruses to decrease the survival time of the pathogen with increasing exposure temperature has been established. Resistance of the virus to repeated sharp changes in temperature (from minus 13 ± 0.5°C to room temperature) without loss of infectious properties was revealed.