Mapping the virome in wild-caught Aedes aegypti from Cairns and Bangkok

Abstract

Medically important arboviruses such as dengue, Zika, and chikungunya viruses are primarily transmitted by the globally distributed mosquito Aedes aegypti. Increasing evidence suggests that transmission can be influenced by mosquito viromes. Herein RNA-Seq was used to characterize RNA metaviromes of wild-caught Ae. aegypti from Bangkok (Thailand) and from Cairns (Australia). The two mosquito populations showed a high degree of similarity in their viromes. BLAST searches of assembled contigs suggest up to 27 insect-specific viruses may infect Ae. aegypti, with up to 23 of these currently uncharacterized and up to 16 infecting mosquitoes from both Cairns and Bangkok. Three characterized viruses dominated, Phasi Charoen-like virus, Humaita-Tubiacanga virus and Cell fusing agent virus, and comparisons with other available RNA-Seq datasets suggested infection levels with these viruses may vary in laboratory-reared mosquitoes. As expected, mosquitoes from Bangkok showed higher mitochondrial diversity and carried alleles associated with knock-down resistance to pyrethroids. Blood meal reads primarily mapped to human genes, with a small number also showing homology with rat/mouse and dog genes. These results highlight the wide spectrum of data that can be obtained from such RNA-Seq analyses, and suggests differing viromes may need to be considered in arbovirus vector competence studies.

The conservation of a core virome inAedesmosquitoes across different developmental stages and continents

“…To investigate the level of conservation of the eukaryotic core viruses identified in Chinese samples from this study with those of other Aedes mosquitoes worldwide, we retrieved 46 published SRA datasets (including 25 datasets of Aedes sp. from Guadeloupe [33], eight from Puerto Rico [24], four from USA [24], seven from Australia [43, 44], one from Thailand [44] and one from China [45]) (Additional file 1 and Fig. 1).…”

De novo profiling of RNA viruses inAnophelesmalaria vector mosquitoes from forest ecological zones in Senegal and Cambodia

“…Similar results were seen in Ae. aegypti , where five ISVs were specific to the Australian host population, while six others were found only in the Thai host population [34]. Differences in the Anopheles virome across geography could be explained by climate, environmental conditions, breeding sites, and mosquito bloodmeal sources, among other factors.…”

Detection of a novel insect specific flavivirus across ecologically diverse populations of Aedes aegypti on the Caribbean Island of Saint Lucia

“…The presence of insect-specific viruses in Ae. aegypti might be underestimated given a recent study suggested up to 27 insect-specific viruses (23 currently uncharacterized) in populations from Cairns (Australia) and Bangkok (Thailand) 50 . The question remains as to whether insect specific viruses like CFAV have not yet gained the ability to infect vertebrates and therefore become arboviruses or whether they have lost this ability 51 .…”