Vector competence of anthropophilic mosquitoes for a new mesonivirus in Senegal

Abstract

The mesoniviruses (MESOVs) belong to the newly described Mesoniviridae family (Order: Nidovirales). They have never been reported in Senegal until recently during a study in arbovirus emergence with the detection of a new species of MESOV named Dianke virus (DKV) from common mosquitoes from eastern Senegal. Actually, their vector competence for this newly described DKV is unknown. We, therefore, estimated the vector competence of Culex tritaeniorhynchus, Culex quinquefasciatus, Aedes aegypti, and Anopheles gambiae mosquitoes collected in Senegal for DKV using oral infection. Whole bodies, legs/wings, and saliva samples were tested for DKV by RT-PCR to estimate infection, dissemination, and transmission rates. The infectivity of virus particles in the saliva was confirmed by infecting C6/36 cells. Virus transmission rates were up to 95.45% in Culex tritaeniorhynchus, 28% in Cx. quinquefasciatus and 9.09% in Aedes aegypti. Viral particles in the saliva were confirmed infectious by C6/36 cell culture. An. gambiae was able to disseminate DKV only at 20 days post-infection. This study shows that Culex mosquitoes are more competent than Ae. aegypti for DKV, while Anopheles gambiae is not likely a competent vector.

Genetic, Morphological and Antigenic Relationships between Mesonivirus Isolates from Australian Mosquitoes and Evidence for Their Horizontal Transmission

“…Indeed, the detection of mesonivirus RNA in the saliva of wild mosquitoes via testing of FTA cards in both our study and that of others [ 16 , 19 ], provides evidence for horizontal transmission during mosquito feeding, although, the possibility of RNA detection from these cards resulting from the presence of infected mosquito body parts such as legs or wings, or indeed, infected excreta should be considered. However, confirmation of mesonivirus transmission via the saliva was recently provided in mosquito transmission studies [ 18 ]. The inability of mesoniviruses to replicate in vertebrate cells from a range of species suggests that a role for viral amplification in a vertebrate host is unlikely and thus, it is more likely that oral infection of mosquitoes occurs via co-feeding of an infected mosquito on the same source, whether that be virus-contaminated nectar or the simultaneous feeding on the same vertebrate [ 43 , 44 , 45 ].…”

“…Indeed, the detection of mesoniviruses in adult male and female mosquitoes supports the hypothesis that mesoniviruses are transmitted from the female mosquito to her progeny [ 16 , 17 ], or via sexual transmission. However, recent studies also provide evidence that horizontal transmission of mesoniviruses is plausible, with the detection of mesonivirus viral RNA in the saliva of infected mosquitoes [ 18 ], as well as on honey-baited cards, upon which mosquitoes expectorate saliva [ 16 , 19 ]. These data suggest several potential routes of mesonivirus transmission between mosquitoes.…”

Transmission competence of a new mesonivirus, Yichang virus, in mosquitoes and its interference with representative flaviviruses

“…tritaeniorhynchus , and Ae . aegypti were highly susceptible to infection and able to transmit DKV [ 25 ]. This may be dependent on mosquito species and the microorganisms carried by the mosquito itself.…”

Assessment of the Risk of Exotic Zika Virus Strain Transmission by Aedes aegypti and Culex quinquefasciatus from Senegal Compared to a Native Strain

“…Their legs and wings were removed and transferred individually into separate tubes, and the proboscis was inserted into a capillary tube containing 1–2 μL of FBS for salivation for up to 30 min. This method has been proven for saliva production and guaranteed that viral particles remain infectious in the collected saliva of competent mosquitoes [ 35 ]. After salivation, each mosquito body (whole body except legs and wings removed) and saliva sample was put into a separate tube and stored separately at −80 °C for detection and quantification of ZIKV by real-time RT-PCR.…”