Experimental infection of Mexican free-tailed bats (Tadarida brasiliensis) with SARS-CoV-2

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus originated in wild bats from Asia, and as the resulting pandemic continues into its third year, concerns have been raised that the virus will expand its host range and infect North American wildlife species, including bats. Mexican free-tailed bats (Tadarida brasiliensis: TABR) live in large colonies in the southern United States, often in urban areas, and as such, could be exposed to the virus from infected humans. We experimentally challenged wild TABR with SARS-CoV-2 to determine the susceptibility, reservoir potential, and population impacts of infection in this species. Of nine bats oronasally inoculated with SARS-CoV-2, five became infected and orally excreted moderate amounts of virus for up to 18 days post inoculation. These five subjects all seroconverted and cleared the virus before the end of the study with no obvious clinical signs of disease. We additionally found no evidence of viral transmission to uninoculated subjects. These results indicate that while TABR are susceptible to SARS-CoV-2 infection, infection of wild populations of TABR would not likely cause mortality. However, the transmission of SARS-CoV-2 from TABR to or from humans, or to other animal species, is a distinct possibility requiring further investigation to better define.