Comparison of Vertebrate Cytochrome b and Prepronociceptin for Blood Meal Analyses in Culicoides.
Authors: Hadj-Henni Leila, De Meulemeester Thibaut, Depaquit Jérôme, Noël Philippe, Germain Adeline, Helder Remi, Augot Denis
Journal: Frontiers in veterinary science
Summary
Culicoides midges are significant vectors of bluetongue virus in European livestock, yet understanding their host preferences depends on accurate identification of blood meal origins from field-caught specimens. Researchers compared two molecular markers—cytochrome b (Cyt b) and prepronociceptin (PNOC)—for identifying host species in 565 blood-fed female midges collected over three years from French localities near livestock and forest habitats, using DNA sequencing to assess detection capability across different stages of blood digestion. Cyt b demonstrated substantially superior performance, successfully identifying 204 additional samples compared to PNOC and achieving a 99.55% identification success rate, particularly for specimens containing partially digested blood; PNOC proved inadequate for differentiating between closely related equid species such as horses and donkeys, with its sequence data for donkeys now available for future reference. The findings emphasise that Cyt b should be the preferred molecular marker for epidemiological surveys aiming to establish Culicoides host preferences and feeding ecology. For equine and livestock practitioners, these results support the use of Cyt b-based blood meal analysis to better understand midge vector behaviour and populations on their properties, ultimately informing bluetongue risk assessment and vector control strategies.
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Practical Takeaways
- •If investigating Culicoides vector control and BTV transmission risk on your property, understand that these midges feed opportunistically on multiple hosts including equines, making vector management challenging
- •Molecular identification of Culicoides blood meals using cytochrome b is the more reliable genetic marker if epidemiological studies are being conducted in your region
Key Findings
- •Cytochrome b (Cyt b) successfully identified blood meal origin in 99.55% of 565 blood-fed Culicoides specimens, compared to prepronociceptin (PNOC) which was less effective
- •Cyt b was superior to PNOC for detecting blood meal origin in females with digested blood in their abdomens
- •PNOC marker cannot reliably distinguish between closely related Equid species such as horses and donkeys
- •Culicoides obsoletus and C. scoticus (main European BTV vectors) demonstrated opportunistic host-feeding behavior on both livestock and wild hosts