Genetic Characterization of Sandfly-Borne Viruses in Phlebotomine Sandflies in Iran

Abstract

Phleboviruses are classified into two main groups: the sandfly fever group (transmitted by sandflies and mosquitoes) and the Uukuniemi group (transmitted by ticks). Old World sandfly-borne viruses (SBVs) are classified into four main serocomplexes; sandfly fever Naples viruses (SFNVs), sandfly fever Sicilian viruses (SFSVs), Karimabad viruses (KARVs), and Salehabad viruses (SALVs). This study addresses current knowledge gaps on SBVs in Iran by focusing on identification and molecular epidemiology. We used PCR to examine DNA/RNA extracts to identify sandfly species and evaluate for SBV presence. We identified five specimens positive for phleboviruses: one Ph. sergenti for Tehran virus (TEHV), one Ph. papatasi for SFSV, and two Ph. papatasi and one Ph. perfiliewi for KARV. A phylogenetic tree indicated that the TEHV isolate from this study formed a cluster with previous isolates of TEHV, Zerdali virus, and Fermo virus. Meanwhile, the identified SFSV isolate fell in lineage I and was grouped with previous isolates of SFSVs and Dashli virus in Iran. Finally, the KARV isolates from this study formed a monophyletic clade in a sister relationship with other viruses in KARV lineages I and II. This comprehensive study on SBVs in Iran provided new insights into the molecular epidemiology of TEHV, SFSVs and KARVs in this country.

Keywords: Iran; Karimabad virus; phlebovirus; phylogenetics; sandfly.

Figure 1

Trapping sites for sandflies collection during the period 2019–2020 in Iran. Sampling locations include site 1: East Azerbaijan Province (Osku), site 2: Mazandaran Province (Babol), site 3: North Khorasan Province (Esfarayen), site 4: Tehran Province (Abardej), site 5: Lorestan Province (Pole Dokhtar), site 6: Isfahan Province (Najafabad), and site 7: Fars Province (Kazerun).

Figure 2

Phylogenetic trees based on the N (A) and NS (B) protein sequences were constructed with the MEGA software V11. The bootstrap values and number of bootstrap replications were greater than 70% and 1000, respectively. The Uukuniemi virus, a tick-borne phlebovirus, and RVFV, a mosquito-borne phlebovirus, were considered as an outgroup. CAR stands for the Central African Republic. SBV sequences obtained in this study are shown in bold.