Detection and Monitoring of Insecticide Resistance Mutations in Anopheles gambiae: Individual vs Pooled Specimens

Area of Science:

• Molecular biology
• Entomology
• Genetics

Background:

• Insecticide resistance management (IRM) relies on monitoring malaria vector populations.
• Molecular diagnostics like TaqMan assays are crucial for detecting resistance mutations.

Purpose of the Study:

• To optimize TaqMan assays for detecting kdr mutations (L1014F, L1014S, N1575Y) in Anopheles gambiae.
• To develop and validate a cost-effective method for estimating allelic frequencies of kdr mutations in pooled mosquito DNA.

Main Methods:

• Optimized triplex and duplex TaqMan assays for specific kdr mutations.
• Created artificial pools of Anopheles gambiae with known genotypes.
• Developed a linear regression model correlating ΔCt values with allelic frequency in pools.

Main Results:

• The regression model achieved high accuracy (r² > 0.99).
• The pooled method demonstrated precision (1.66–2.99%) and accuracy (3.3–5.9%).
• Successfully detected the N1575Y mutation in field samples from Mali, previously unrecorded.

Conclusions:

• Pooling mosquito DNA significantly enhances the efficiency of resistance allele screening.
• This method facilitates effective insecticide resistance management by providing rapid genetic insights.
• The validated pooled assay offers a precise and accurate alternative to individual genotyping for large-scale monitoring.