Abstract
Next-generation sequencing (NGS) has the potential to transform
mosquito-borne disease surveillance but remains under-utilized. This
study introduces a comprehensive multi-loci metabarcoding-based MX
(molecular xenomonitoring) approach to mosquito and arbovirus
surveillance, enabling parallel identification of mosquito vectors,
circulating arboviruses, and vertebrate hosts from bulk mosquito
collections. The feasibility of this approach was demonstrated through
its application to a large set (n=134) of bulk field collections. This
set was complemented by a number (n=28) of single-species mosquito pools
that had previously been screened for viruses using quantitative reverse
transcription PCR (RT-qPCR) and metatranscriptomics. Universal
alphavirus and flavivirus primer sets were used to screen for
arboviruses in the resulting metabarcoding library. Viral amplicons were
then indexed and combined with mosquito-specific (ITS2), universal
invertebrate (COI), and vertebrate (Cyt b) barcode
amplicons prior to sequencing. This approach confirmed the presence of
all previously identified mosquito species, as well as those commonly
misidentified morphologically, and enabled a degree of quantification
regarding their relative physical abundance in each collection.
Additionally, the developed approach identified a diverse vertebrate
host community (18 species), demonstrating its potential for defining
host preferences and, in tandem with the viral screens and associated
vector data, understanding disease transmission pathways. Importantly,
metabarcoding detected a diversity of regionally prevalent arboviruses
and insect-specific viruses, with all three viral diagnostics
demonstrating a similar sensitivity and specificity in detecting Ross
River virus and Barmah Forest virus, Australia’s commonest arboviruses.
In summary, multi-loci metabarcoding is an affordable and efficient MX
tool that enables complete mosquito-borne disease surveillance.