Host selection pattern and flavivirus screening of mosquitoes in a disturbed Colombian rainforest

Abstract

Studies on the feeding behavior of hematophagous insects, particularly those of medical importance, are relevant for tracking possible pathogen transmission routes and identifying biases in the choice of vertebrates. We evaluated host selection of blood-feeding mosquitoes in a disturbed forest in the Magdalena Medio valley in Colombia from March 2017 to April 2018, after the introduction of Zika virus to the Americas from the 2015–2016 outbreak. We estimated vertebrate diversity and collected blood-engorged female mosquitoes. Genomic DNA/RNA was extracted from the mosquito’s abdomen for vertebrate host identification and pathogen detection. We performed conventional PCR and sequencing, using universal primers targeting vertebrate regions of the eukaryotic mitochondrial genome to determine bloodmeal host. Additionally, we tested for the presence of flaviviruses in all mosquito samples with RT-PCR. Based on the identity and quantity of detected bloodmeals, we performed mosquito-vertebrate interaction network analysis and estimated topology metrics. In total, we collected 292 engorged female mosquitoes representing 20 different species. Bloodmeal analyses identified 26 vertebrate species, the majority of which were mammals (N = 16; 61.5%). No flaviviruses of medical importance were detected from the samples. Although feeding patterns varied, network analyses showed a high degree of specialization by mosquitoes and revealed ecological and phylogenetic relationships among the host community. We conclude that host selection or preference by mosquitoes is species specific.

Employing oxford nanopore technologies (ONT) for understanding the ecology and transmission dynamics of flaviviruses in mosquitoes (Diptera: Culicidae) from Eastern Colombia

“…Similar studies have reported such challenges due to the diversity and taxonomic revisions gaps in the Culex genus. (Hoyos et al, 2021;Torres-Gutierrez and Sallum, 2015). Therefore, in these cases, the COI gene has been established to classify mosquito species based on inter-and intraspecific genetic distances (Torres-Gutierrez et al, 2016).…”

“…The second study by Hoyos et al (2021) found 25 positive samples for the detection of the NS5 gene fragment. However, sequencing of these fragments by Sanger failed to detect known Flavivirus sequences (Hoyos et al, 2021). The limitations of Sanger sequencing are highlighted in cases where the presence of multiple viral species of Flavivirus may occur.…”

“…This is due to two factors. Firstly, vectors may be co-infected with different flaviviruses, and sequencing techniques, such as the Sanger method, cannot identify them (Hoyos et al, 2021). Secondly, the next-generation sequencing (NGS) technique, Illumina, commonly used for vector virome characterization, provides sufficient information to assemble viral genomes and identify co-infections, but at the economic level it ends up generating high costs and its accessibility is limited, particularly in endemic areas or areas with restricted resources (Gómez et al, 2022).…”

“…In Colombia, two studies stand out; The first study was conducted by Hoyoz-López, R. et al (2016), in which they identified flaviviruses of epidemiological importance such as St. Louis encephalitis virus (SLEV), WNV, and ISFV like CxFV, in individuals of Culex (Hoyos-López et al, 2016). The second study by Hoyos et al (2021) found 25 positive samples for the detection of the NS5 gene fragment. However, sequencing of these fragments by Sanger failed to detect known Flavivirus sequences (Hoyos et al, 2021).…”

Evolution and emergence of mosquito-borne viruses of medical importance: towards a routine metagenomic surveillance approach

“…Emergence zone Urban cycle As a spillover event, humans could be exposed to an arbovirus by contact with vectors entering areas of human settlements (e.g. rural or peri-urban areas of populated centres and indigenous communities living far from the cities) in search of blood meals, mainly through bridge vectors that could move and feed on several vertebrate hosts in transition zones (Hoyos et al 2021); by the direct incursion of people in sylvatic settings for several activities, such as hunting, deforestation and mining (Valentine et al 2019); by the contact of a vertebrate host or reservoir from the enzootic cycle with vectors from the urban area that could lead to virus adaptation to a new potential vector and host; and finally, by the initial adaptation to domestic vertebrates; the virus could reach the human host. The result of the interaction of a new viral entity with humans could be unpredictable as the introducing virus might not find a suitable or permissive host to replicate and reach enough viral titers to establish a second round of infection (Weaver et al 2018); therefore, humans act as a dead-end host, impeding new rounds of transmission from this source (Ellwanger & Chies 2021).…”