Permethrin Resistancein Field Populations of Rhipicephalus sanguineus sensu lato (Latrielle, 1806) Collected From Dogs in Eastern Iran.

Abstract

Introduction: The high level of acaricide resistance in ticks has become a challenge for dog owners in Iran.

Materials & methods: This study was conducted in South Khorasan Province of Iran in 2024. In this study, the resistance status of Rhipicephalus sanguineus (Acari Ixodidae) to permethrin at various concentrations was evaluated using the larval packet test (LPT) method recommended by the Food and Agriculture Organization (FAO). Polymerase chain reaction (PCR) assays were conducted to investigate the mechanisms of resistance to acaricides. We used PCR to amplify segment 6 of domain III of the voltage-sensitive sodium channel protein from both pyrethroid-susceptible and pyrethroid-resistant tick strains.

Results: The LPT discriminating dose bioassays confirmed the pyrethroid resistance phenotype of the analyzed strains. The mortality rate at LC99 ranged between 38.1 and 49.1%. At the discriminating dose, survival rates ranged from 48.3% to 60.1%. Additionally, of the 40 ticks analyzed, mutations C2130T and T2134C were detected in 38(95%) ticks.

Conclusion: The presence of permethrin resistance in R. sanguineus populations in Iran highlights the need for alternative control strategies, and the identification of genetic mutations provides valuable information for understanding the mechanisms of resistance.