Multiple Phlebovirus (Bunyaviridae) genetic groups detected in Rhipicephalus, Hyalomma and Dermacentor ticks from southern Portugal

In the last decade, various research groups have reported a large diversity of new tick-borne phleboviruses, mostly prompted by the discovery of important human pathogens such as the Heartland and severe fever with thrombocytopenia syndrome viruses. Since these analyses have rarely been conducted using ticks collected from Southern Europe, this study was carried out so as to bring new insights into the diversity of phleboviruses circulating in Southern Portugal. Tick specimens were collected from the vegetation (questing ticks) or directly from animals (feeding ticks), and the majority analysed in pools using a detection strategy targeting the large (L) viral genomic segment. A high number of pools revealed the presence of phebovirus sequences, regardless of gender (male/female), origin (questing/feeding) or even species of the tick analysed. These sequences apparently formed three different groups in phylogenetic trees, and encoded L proteins characterized by group-specific amino acid residues. Furthermore, under the conditions used, these viruses failed to replicate in both Vero and DH82 cells. The impact these viruses may have on human/animal health will be addressed in the future.