Viromics Reveal a Number of Novel RNA Viruses in Swedish Mosquitoes

Abstract

Metagenomic studies of mosquitoes have revealed that their virome is far more diverse and includes many more viruses than just the pathogenic arboviruses vectored by mosquitoes. In this study, the virome of 953 female mosquitoes collected in the summer of 2017, representing six mosquito species from two geographic locations in Mid-Eastern Sweden, were characterized. In addition, the near-complete genome of nine RNA viruses were characterized and phylogenetically analysed. These viruses showed association to the viral orders Bunyavirales, Picornavirales, Articulavirales, and Tymovirales, and to the realm Ribovira. Hence, through this study, we expand the knowledge of the virome composition of different mosquito species in Sweden. In addition, by providing viral reference genomes from wider geographic regions and different mosquito species, future in silico recognition and assembly of viral genomes in metagenomic datasets will be facilitated.

Viromics on Honey-Baited FTA Cards as a New Tool for the Detection of Circulating Viruses in Mosquitoes

“…In agreement with previous virome studies, most of the taxa derived from honey-baited FTA cards have been identified in various invertebrates [39] and associated to mosquitoes [40]. Additionally, mosquito-specific viruses detected in FTA cards (Table 2) have been described as part of the viral communities harbored by several mosquito species in different geographic regions [41][42][43][44][45][46][47][48]. Bold type corresponds to the selected viruses for primers design.…”

“…The additional description of honeybee-infecting virus Rhopalosiphum padi virus (Dicistroviridae, genus Cripavirus) in mosquito species from Hubei, China [51] and in Culex mosquitoes from California [41], together with the assembly of sequences linked to chronic bee paralysis virus (CBPV) (unclassified ssRNA+ virus) and Apis mellifera filamentous virus (dsDNA Hytrosaviridae family) from French Anopheles maculipennis [52] and from Culex mosquitoes from California [41] respectively, suggested that these viral families could be associated to mosquitoes as well. In addition, due to the low genetic identity of these viruses with their closest honeybee counterpart, the scarcity of mosquito-based sequences available in public databases, and the continuous discovery of new picorna-like viruses in insects [41,45,50,53,54], might suggest that we are dealing with novel mosquito picorna-like viruses. Based on the abovementioned findings, captured mosquitoes that fed on the FTA cards could have been the source of the identified viruses.…”

“…Besides invertebrate-related viruses, it was not surprising to find viral families usually detected in plants, fungi and algae (e.g., Tymoviridae, Totiviridae, Partitiviridae, Endornaviridae or Virgaviridae) as part of the viral diversity associated to honey-baited FTA cards ( Figure 1B). Since, in Culex mosquitoes, sequences related to Totiviridae-like viruses have been found in Guadeloupe [46], Australia [25], China [49] and California [41]; Partitiviridae-like viruses have been detected in Sweden [45,48], Australia [25], Kenya [49] and California [41]; Endornaviridae-like viruses in Australia [25] and Tymoviridae-like viruses have been identified in Guadeloupe [46], Kenya [49], California [41], China [53], and Sweden [48]. Moreover, a Culex Tymoviridae-like virus (CuTLV) that was isolated from a Culex spp.…”

Stability of the Virome in Lab- and Field-Collected Aedes albopictus Mosquitoes across Different Developmental Stages and Possible Core Viruses in the Publicly Available Virome Data of Aedes Mosquitoes

“…Some studies have performed viral metagenomics on field mosquitoes collected from different countries (including the United States, Puerto Rico, China, Kenya, Australia, Sweden, etc. ), mainly focusing on novel virus discovery (16)(17)(18)(19)(20)(21)(22)(23)(24). Some newly discovered mosquito-specific viruses (MSVs) have been proposed as future biological control agents against arboviruses (25)(26)(27) or as novel vaccine platforms (27) or used in diagnostic assays in chimeric virus formation with structural protein genes from arboviruses (27).…”

Virome Temporal Variation During Sea Star Wasting Disease Progression in Pisaster ochraceus (Asteroidea, Echinodermata)

“…Picornaviruses (+ssRNA) feature prominently in most host-associated virome surveys [21][22][23][24][25][26][27][28][29][30][31][32] and are ubiquitous in marine plankton as free particles [33][34][35][36][37][38][39]. Of the 19 picornairus-like genome fragments recovered in this survey, 9 matched most closely to dicistroviruses (Dicistroviridae), 2 to bacillarnaviruses (Marnaviridae), and 1 to caliciviruses (Caliciviridae) by BLASTx (Fig.…”