Identification of a novel group 1 coronavirus from Chinese horseshoe bats
Abstract number: P1901
Lam C.S.F., Lau S.K.P., Woo P.C.Y., Li K.S.M., Huang Y., Wang M., Xu H., Guo R., Chan K.H., Zheng B.J., Yuen K.Y.
Objectives: We conducted an extensive surveillance for coronaviruses in Chinese horseshoe bats in Hong Kong and Guangdong province of Southern China, in order to better understand the epidemiology and evolution of the novel group 1 coronavirus and explore possible recombination events between this coronavirus and bat-SARS-CoV that could have led to the emergence of SARS-CoV.
Methods: The respiratory and alimentary specimens of Chinese horseshoe bats (Rhinolophus sinicus) were collected and subjected to RNA extraction and RT-PCR for coronaviruses. Those positive samples were sequenced and analysed by comparing with the sequences of the pol genes of known coronaviruses in the GenBank database. Four complete genomes of bat-CoV detected in the present study were amplified and sequenced.
Results: A total of 770 respiratory and alimentary specimens from 348 and 64 Chinese horseshoe bats were obtained in Hong Kong and in the Guangdong province in Southern China, respectively. RT-PCR for a 440-bp fragment in the RdRp genes of coronaviruses was positive in alimentary specimens from 58 (16.7%) of the 348 bats from Hong Kong, and from 8 (12.5%) of the 64 bats from Guandong. None of the respiratory specimens was positive. Sequencing results suggested the presence of two different coronaviruses among the 64 positive bats. Complete genome sequencing of four strains of bat-CoV revealed the smallest coronavirus genome (27164 nucleotides) and a unique spike protein evolutionarily distinct from the rest of the genome. This spike protein, sharing similar deletions with other group 2 coronaviruses in its C-terminus, also contained a 15-amino acid peptide homologous to a corresponding peptide within the RBM of spike protein of SARS-CoV, which was absent in other coronaviruses except bat-SARS-CoV. Further studies are required to determine if inter-group gene exchange was responsible for the origin of the spike of bat-CoV and its possible role in the evolution of the spike of SARS-CoV.
Conclusion: This is the first report that documents the presence of a spike evolutionarily distinct from the other parts of the coronavirus genome. It also suggests that the RBM of SARS-CoV and the corresponding region in bat-CoV and bat-SARS-CoV share different degrees of homologies, consistent with the hypothesis that the RBM of SARS-CoV may have originated from recombination events.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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