Molecular characterization of rabies virus from wild and domestic animals in the Sultanate of Oman

Aims

Rabies virus (RV) is endemic in some Arabian countries. However, it is difficult to control RV without understanding the epidemiological evolution of endemic RV isolates. The current study aimed to characterize RV from domestic and wild animal clinical cases in Oman.

Methods and Results

Twelve brain samples from domestic (Five camels, three goats and one cattle) and wild animals (Two foxes and one honey badger) were investigated from different locations in Oman between 2017 and 2020. All samples were confirmed by RV nucleoprotein (N) gene-specific primers. Seven out of the 12 amplified samples were successfully sequenced and subjected to sequence and phylogenetic analysis. The detected RVs shared an in-between 96.8%–98.7% and 96.9%–99% nucleotide and amino acid identities, respectively. However, the wild animal RVs shared only 92.6%–93.9% and 95.9% nucleotide and amino acid identities with the domestic animal RVs, respectively. Negri bodies were detected histologically in six brain samples from camels (n = 3), goats (n = 1) and foxes (n = 2). The RVs from domestic animals shared 97%–98.7% and 98%–100% nucleotide and amino acid identities with the previously published fox RVs from Oman and Gulf countries. Phylogenetic analysis suggested that all RV sequences belong to a distinct clade confined to the previously reported clade V within the Middle Eastern Cluster.

Conclusions

As indicated by the analysis of RVs from different locations between 2017 and 2020, a genetic variant isolated to the Gulf region may exist within the Middle East clade. Moreover, it appears that new RV lineages are emerging rapidly within this region. Therefore, a comprehensive genomic and phylogenetic analysis of the circulating RV is important for the development of future prevention and control strategies.