Detecção de vírus inseto-específicos e arbovírus em culicíneos no Pantanal e em Cuiabá, Mato Grosso

Abstract

Hematophagous culicines are responsible for the transmission of several public health arboviruses and infected with a wide diversity of insect-specific viruses. Therefore, its important to know the circulation of vectors and viruses in the territory of Mato Grosso. The present study investigated the natural infection rate by arboviruses in Aedes aegypti and Aedes albopictus reared from eggs collected with ovitraps in Cuiabá and the identification of the virome in the saliva of mosquitoes captured in RAPELD grids in the Pirizal region, High Pantanal, Mato Grosso. In total, 4490 Aedes aegypti and 296 Aedes albopictus reared from eggs collected with ovitraps in Cuiabá from February to July, 2017 were subjected to viral RNA extraction and reverse transcriptasepolymerase chain reaction protocols for 10 flaviviruses and 5 alphaviruses, nucleotide sequencing and three passages in C6/36 cells; eight pools of Ae. aegypti were positive for dengue virus 4 (DENV-4), seven for Zika virus (ZIKV) and two for Mayaro virus (MAYV). In addition, two Ae. albopictus pools were positive for DENV-4 and other two for ZIKV. Infection was confirmed by viral isolation in all positive pools for DENV-4 and for MAYV and in 8/9 for ZIKV. This mechanism may contribute to the spread of arboviruses during epidemics and also to their maintenance in natural vectors during interepidemic periods. In the Pantanal, 1657 mosquitoes were collected during three campaings in 2014-2015 with Nasci aspirators and CDC light traps and allocated into 31 pools after identification with dichotomy keys and salivary glands dissection. Pools were subjected to viral RNA extraction, double-strand cDNA synthesis, random amplification by PCR and high throughput sequencing (Illumina HiSeq 2500). We found 14 viral sequences, including 8 new viruses belonging to the families Iflaviridae (Psorophora albigenu iflavirus), two members of Phenuiviridae (Aedes scapularis phlebovirus and Sabethes gymnothorax phlebovirus), two Rhabdoviridae (Coquillettidia vesiculovirus and Lobeira virus), two Flaviviridae (Aedes flavivirus 2 and Sabethes flavivirus), one Reoviridae (Sabethes gymnothorax chuvirus), one Chuviridae (Sabethes gymnothorax chuvirus), one Circoviridae (Psorophora albigenu circovirus), one Partitiviridae (Araticum virus) and one Totiviridae (Murici virus). These results underscore the high viral diversity existent in urban and sylvatic areas of MatoGrosso.