Discovery of Novel Viruses in Mosquitoes from the Zambezi Valley of Mozambique

Abstract

Mosquitoes carry a wide variety of viruses that can cause vector-borne infectious diseases and affect both human and veterinary public health. Although Mozambique can be considered a hot spot for emerging infectious diseases due to factors such as a rich vector population and a close vector/human/wildlife interface, the viral flora in mosquitoes have not previously been investigated. In this study, viral metagenomics was employed to analyze the viral communities in Culex and Mansonia mosquitoes in the Zambezia province of Mozambique. Among the 1.7 and 2.6 million sequences produced from the Culex and Mansonia samples, respectively, 3269 and 983 reads were classified as viral sequences. Viruses belonging to the Flaviviridae, Rhabdoviridae and Iflaviridae families were detected, and different unclassified single- and double-stranded RNA viruses were also identified. A near complete genome of a flavivirus, tentatively named Cuacua virus, was obtained from the Mansonia mosquitoes. Phylogenetic analysis of this flavivirus, using the NS5 amino acid sequence, showed that it grouped with ‘insect-specific’ viruses and was most closely related to Nakiwogo virus previously identified in Uganda. Both mosquito genera had viral sequences related to Rhabdoviruses, and these were most closely related to Culex tritaeniorhynchus rhabdovirus (CTRV). The results from this study suggest that several viruses specific for insects belonging to, for example, the Flaviviridae and Rhabdoviridae families, as well as a number of unclassified RNA viruses, are present in mosquitoes in Mozambique.

Deciphering the Virome of Culex vishnui Subgroup Mosquitoes, the Major Vectors of Japanese Encephalitis, in Japan

“…The abundance and diversity of possible ISVs constituted a significant component of Culex mosquito viromes; for example, the virome of Culex spp. in Zambezi, Mozambique was dominated (88.5%) by them [48], whereas a study of the C. tritaeniorhynchus virome in Hubei, China also showed a conformable predominance (88%) of insect viruses [18]. In line with the reckonings, the result displayed a practically similar constitution, as much as 84%, 82%, and 100% of viruses were insect viruses, or had a high correlation with the mosquito virome previously identified, in C. tritaeniorhynchus, C. pseudovishnui, and C. inatomii, respectively (Supplementary Figure S4), implying a consistent virome composition in Culex mosquitoes, with slight variations possibly associated with the number of samples used.…”

Viral metagenomics reveals the presence of highly divergent quaranjavirus inRhipicephalusticks from Mozambique

“…First strand cDNA synthesis, followed by labeling of cDNA and random amplification, was performed with 10 µl of RNA, as described by Cholleti et al 2016 [17]. The final amplified product were submitted to the National Genomics Centre (SciLife Lab, Uppsala, Sweden) for library preparation and sequencing.…”

Genomes of viral isolates derived from different mosquitos species

“…During the past decade, advances in DNA sequencing technology have allowed the identification of a wide range of novel viruses associated with mosquitoes (Aguiar et al, 2015; Auguste et al, 2014; Bolling et al, 2015; Carissimo et al, 2016; Chandler et al, 2015; Charles et al, 2016; Cholleti et al, 2016; Coffey et al, 2014; Contreras-Gutierrez et al, 2017; Fauver et al, 2016; Frey et al, 2016; Li et al, 2015a; Li et al, 2015b; Nasar et al, 2012; Ng et al, 2011; Palacios et al, 2015; Pauvolid-Correa et al, 2016; Shi et al, 2015; Simmonds et al, 2017; Vasilakis et al, 2014a; Wang et al, 2015). We examine here, by electron microscopy and metagenomics analysis, 11 mosquito derived viral isolates from the extensive collection of the World Reference Center for Emerging Viruses and Arboviruses (WRCEVA) (https://www.niaid.nih.gov/research/wreceva), whose morphology indicated the likely presence of multi-segmented reoviruses.…”