Abstract
The variety and widespread of coronavirus in natural reservoir animals
is likely to cause epidemics via interspecific transmission, which has
attracted much attention due to frequent coronavirus epidemics in recent
decades. Birds are natural reservoir of various viruses, but the
existence of coronaviruses in birds, especially in central China, has
been barely studied. The majority of bird coronaviruses belongs to the
genus of Deltacoronavirus. To explore the diversity of bird
deltacoronaviruses in central China, we tested fecal samples from 415
birds in Hunan Province, China. As the result, we have identified four
novel deltacoronavirus stains (HNU1-1, HNU1-2, HNU2 and HNU3) with
divergent S genes abounding in common magpies in mainland China.
Comparative genomic analysis on the four complete viral genomic
sequences showed that these novel magpie deltacoronaviruses containing
three different S genes homologous to those of deltacoronaviruses
discovered in swine and sparrows. The S genes of HNU1-1 and HNU1-2
showed 93.8% amino acid sequence identities to that of thrush
coronavirus HKU12, and the S genes of HNU2 and HNU3 showed 71.1% amino
acid sequence identities to White-eye coronavirus HKU16 and sparrow
coronavirus HKU17, respectively. Recombination analysis showed that
frequent recombination events of the S genes occurred among different
deltacoronavirus strains. Two novel putative cleavage sites at the
junctions between nonstructural proteins in the HNU CoVs were found.
Bayesian phylogeographic analysis showed that the south coast of China
might have played a key role in seeding the bird deltacoronavirus
epidemics. The results demonstrated that common magpie in China carries
diverse deltacoronaviruses with novel genomic features, which indicate
an important source of environmental coronaviruses in the biosphere
closed to human communities. These findings may contribute to prevention
and control the potential coronavirus epidemics.