Genetic survey of Ivermectin-resistance markers in head lice from Jazan, Saudi Arabia.

Insecticide resistance in head lice is a widespread problem and has been intensively studied in recent years. Whereas numerous investigations have examined pyrethroid resistance, ivermectin (IVM) resistance has not been assessed in Saudi Arabia and has been addressed in few studies worldwide. IVM is the second most commonly used drug to treat head-louse infestations, and resistance to it is associated with five mutations in the glutamate-gated chloride channel (GluCl) gene. This study aimed to estimate the prevalence of GluCl mutations in the Jazan region. Sanger sequencing and PCR-restriction fragment length polymorphism (PCR-RFLP) were used to genotype the A251V, S46P, H272R, N143D, and T236A mutations in 62 samples. A251V was the most prevalent mutation in Jazan, with an allele frequency of 0.78. The highest mutant-allele frequencies were observed in the southern and eastern regions (0.85 and 1.00, respectively). Additional toxicological, pharmacological, and molecular surveillance studies are necessary.