Next generation sequencing approach for simultaneous identification of mosquitoes and their blood-meal hosts

Authors: Muturi, Ephantus; Dunlap, Christopher; TCHOUASSI, DAVID - International Centre Of Insect Physiology And Ecology; SWANSON, JACK - Illinois Department Of Public Health

Submitted to: Journal of Vector Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/2/2021
Publication Date: 6/14/2021
Citation: Muturi, E.J., Dunlap, C.A., Tchouassi, D.T., Swanson, J. 2021. Next generation sequencing approach for simultaneous identification of mosquitoes and their blood-meal hosts. Journal of Vector Ecology. 46(1):116-121. https://doi.org/10.52707/1081-1710-46.1.116 .
DOI: https://doi.org/10.52707/1081-1710-46.1.116

Interpretive Summary: Females of many mosquito species take blood meals from diverse vertebrate host species. During this process, these females can acquire and subsequently transmit devastating disease-causing agents to humans and animals. Different mosquito species and vertebrate host species differ in their contribution to disease transmission cycle. Therefore, accurate identification of mosquito species and their blood meal hosts is a critical component of mosquito-borne disease surveillance and control. Morphological identification of mosquitoes is possible, but loss of morphological characters in field-collected samples and presence of morphologically identical mosquito species complicates this process. Some mosquitoes also feed on multiple vertebrate host species and conventional molecular approaches for blood meal identification are poorly designed to identify mixed blood meals. We describe a proof-of-concept next-generation sequencing approach (NGS) for simultaneous identification of mosquitoes and their blood meal hosts including mixed blood meals. This approach was effective at identifying mosquito species and their blood meal sources including mixed blood meals. This NGS approach can enhance vector surveillance and control via rapid and accurate identification of mosquito species and potential reservoir hosts.

Technical Abstract: Accurate identification of disease vectors and their host feeding patterns is critical for understanding disease dynamics and transmission cycles. We describe a proof-of-concept next-generation sequencing approach for simultaneous identification of mosquitoes and their blood meal hosts including mixed blood meals. Aedes aegypti colony was artificially fed on blood from known vertebrate hosts (bovine, sheep, horse, rabbit, porcine or a mixture of bovine, sheep, horse and rabbit blood) and a DNA fragment targeting cytochrome b gene amplified and sequenced for blood meal identification. Additionally, a DNA fragment targeting insect-specific segment of cytochrome oxidase 1 gene was amplified from Ae. aegypti and field-collected samples of Culex pipiens, Aedes albopictus, and Ochlerotatus triseriatus and sequenced for mosquito identification. The resulting sequences were compared against DNA sequences present in the GenBank. All blood meals were correctly assigned to their respective vertebrate hosts. A few sequences were spuriously assigned to Ae. aegypti or did not match any host at 97% similarity and in one of the 5 mixed blood meal samples, bovine blood meal was not detected. For mosquito identification, all except one Ae. aegypti sample and one Oc. triseriatus sample that had low quality sequences were molecularly identified. However, samples that were morphologically identified as Oc. triseriatus were molecularly identified as Oc. hendersoni and a few sequences from one Ae. aegypti sample were molecularly identified as Aedes mascarensis. These findings demonstrate that this NGS approach can enhance vector surveillance and control via rapid and accurate identification of mosquito species and potential reservoir hosts, but further improvements may be needed for identification of closely related species.