Viral isolates of a novel putative phlebovirus in the Marche Region of Italy

Abstract

Thirty pools from 900 (540 females and 360 males) Phlebotomus perfiliewi sandflies collected during the summer of 2012 in the Fermo area (Marche Region, central Italy) were tested for the presence of Phleboviruses. A nested polymerase chain reaction was performed using degenerated primers amplifying a fragment of the polymerase gene (large segment) and a fragment of the nucleoprotein gene (small segment) of the genus Phlebovirus. One pool was positive for Toscana virus, as expected from results of studies in the area, and six pools were positive for a putative novel Phlebovirus. Virus isolation in Vero cells was performed. Minimum field infection rates/1,000 insects processed for the novel and Toscana viruses were 6.7 and 1.0, respectively. Phylogenetic analysis of the novel Phlebovirus, tentatively named Fermo virus, placed it in the Sandfly Fever Naples virus serocomplex.

Figure 1.

Marche Region of central Italy showing the study site (Fermo commune) where Fermo virus was isolated during the summer of 2012.

Figure 2.

Phylogenetic trees of partial sequences of A, polimerase segment (L) and B, nucleoprotein segment (S) of Marche Region isolates and other selected phleboviruses. Trees were constructed by using the neighbor-joining method and 1,000 bootstrap values. Analysis was performed in Mega version 5.2 (www.megasoftware.net/). Sequences were aligned by using Clustal W (www.clustal.org/). Prototype sequences with accession numbers are indicated. Accession numbers of Fermo virus (FERV) sequences are Fer-IT8 HG321367, Fer-IT9 HG793786, Fer-IT15 HG793787, Fer-IT16 HG793791, FerIT18 HG793788, Fer-IT20 HG793789, and Fer-IT30 HG793790. Strains of the novel virus isolated in this study are indicated in bold. Scale bars indicate percentage diversity. TOSV = Toscana virus; SFSV = sandfly fever Sicilian virus; SFTV = sandfly fever Turkey virus; TehV = Tehran virus; SFNV = sandfly fever Naples virus; ArbV = Arbia virus.