MERS coronaviruses from camels in Africa exhibit region-dependent genetic diversity

Archive ouverte

Chu, D.K.W. | Hui, K.P.Y. | Perrera, R.A.P.M. | Miguel, Eve | Oladipo, J.O. | Traoré, A. | Fassi-Fihri, O. | Chan, M.C.W. | Zhou, Z. | So, R.T.Y. | Chevalier, V. | Peiris, J.S.M.

Edité par CCSD ; Oxford University Press -

Middle East respiratory syndrome coronavirus (MERS-CoV) causes a zoonotic respiratory disease of global public health concern, and dromedary camels are the only proven source of this zoonotic infection. Although MERS-CoV infection is ubiquitous in dromedaries across Africa and the Arabian Peninsula, the continuous appearance of zoonotic MERS cases in humans is confined to the Arabian Peninsula. MERS-CoV from Africa has hitherto been poorly studied. Here, we report the genetic and phenotypic characterization of MERS-CoV from dromedaries in African countries. Phylogenetically, viruses from dromedaries in Africa formed a monophyletic clade, which we have provisionally designated as virus clade C. Molecular dating analyses of MERSCoV, including clade C viruses, suggests that the ancestral MERSCoV in dromedaries could have spread to the two continents within a short timeframe. Camel MERS-CoVs fromwest and north African countries form a subclade (C1) that shares genetic signatures of a major deletion in the accessory gene ORF4b. Compared with human and camel MERS-CoV from Saudi Arabia, virus isolates from Burkina Faso (BF785) and Nigeria (Nig1657) had lower virus replication competence in Calu-3 cells and in ex vivo cultures of human bronchus and lung, and BF785 replicated to lower titer in lungs of human DPP4-transduced mice. However, it is still inconclusive whether ORF4b deletions may lead to the reduced replication competence of BF785 and Nig1657. Genetic and phenotypic differences in West African viruses may be relevant to the zoonotic potential of MERS-CoV.

• Description
• Sujet/Public
• Outil
• Outil d'anticipation
• Mémoire et thèse
• Gestion