TOPICS ON MOLECULAR CHARACTERIZATION OF THE NOVEL CORONAVIRUS SPECIES SARS-CoV-2

Abstract

Since December 2019, a new coronavirus species named SARS-CoV-2 has been related to thousands of cases of severe respiratory disease worldwide, been considered a public health issue. Molecular comparisons between isolates from SARS-CoV-2 and other coronavirus species showed identity levels around 79% with the human strain SARS-CoV. However, sequence homology analysis showed that the most closely related known viruses with SARS-CoV-2 are two bat SL-CoVs (~89%), revealing similar evolutionary relationships and evidences that bats can act as reservoirs of SARS-CoV-2. Despite this, viral RNA has been detected in two dogs and two cats belonging to SARS-CoV-2 infected owners, in Hong Kong and Belgium, and in one tiger maintained at the Bronx Zoo in New York City. Additionally, ferrets and cats are found to be highly susceptible to SARS-CoV-2 in an experiment carried out in a controlled environment. However, there is no evidence of these animals acting as reservoirs of the virus. Despite the high genetic identity found among SARS-CoV-2 strains, mutations have been identified, mostly in the structural protein S gene, but until now, there is no enough evidence to relate specific mutation in the viral genome to a higher number of infected patients or death.