Fig. 1.

Isolates of coronaviruses discussed in this review and their receptors, host and reservoirs. SARS-CoV and SARS-CoV-2 from the lineage B use ACE2 as receptor. MERS-CoV from the lineage C enters into host cells by binding DPP4. SARS-CoV has the masked palm civets as an intermediate host in which the virus has adapted from the Chinese Horseshoe bat reservoir to ultimately infect humans [13]. SARS-CoV-2 has bats and pangolins as natural reservoir and can infect ferrets or domestics animals, with a high susceptibility in cats [14]. MERS-CoV has the origin from bats [15] but maybe this virus had an adaptation through camels before its emergence into human [16].