Replicative Capacity of MERS Coronavirus in Livestock Cell Lines

Abstract

Replicative capacity of Middle East respiratory syndrome coronavirus (MERS-CoV) was assessed in cell lines derived from livestock and peridomestic small mammals on the Arabian Peninsula. Only cell lines originating from goats and camels showed efficient replication of MERS-CoV. These results provide direction in the search for the intermediate host of MERS-CoV.

Keywords: Arabian Peninsula; MERS; Middle East respiratory syndrome; camels; cell culture; coronavirus; goats; intermediate host; livestock; viruses; zoonoses; zoonosis; zoonotic.

Figure 1

Immunofluorescence staining of the Middle East respiratory syndrome coronavirus receptor dipeptidyl peptidase 4 (DPP-4; rabbit anti-CD26/DPP-4 polyclonal antibody; Bioss Inc., Woburn, MA, USA) in cell lines used to guide the search for the intermediate host of the virus. Counterstaining of nuclei was done by using 4′,6-diamidino-2-phenylindole. Cell lines: A) ZN-R, B) ZLu-R, C) LGK-1-R, D) TT-R.B, E) PO, F) KN-R, G) KLu-R, H) MyglaAEC.B, I) Crocsu-Lu, J) PipNi, K) A549, and L) Vero E6. Magnification 400-fold.

Figure 2

Analysis of the replication of Rift Valley fever virus (RVFV) clone 13 (A), bovine coronavirus (BCoV) (B), and Middle East respiratory syndrome coronavirus (MERS-CoV) (C) and of the production of infectious MERS-CoV particles (D) in cell lines derived from livestock and peridomestic small mammals on the Arabian Peninsula. Cell lines of human, bat, and primate origin were used as controls. Replication levels for each virus used are given as log of the genome equivalents (GEs) (A–C) or as plaque-forming units (PFUs). Vertical bars indicate ranges; horizontal bars indicate cell line origins. Using panel C as a reference, symbols represent (left to right) goat, alpaca, Arabian camel, sheep, cattle, bank vole, shrew, bat, human, and African green monkey. ND, not detected; hpi, hours postincubation.