Evaluation of fipronil efficacy and first molecular report of gamma-aminobutyric acid (GABA) gated chloride channel gene of Rhipicephalus microplus ticks in China and Pakistan

作者：Muhammad Kashif Obaid, Qiaoyun Ren, Jin Luo, Jinming Wang, Muhammad Rashid, Jehan Zeb, Xiaoqing Zan, Xinting Lan, Guangyuan Liu, Jianxun Luo, Hong Yin, Ze Chen, Guiquan Guan · 发表于：Veterinary Parasitology · 年份：2025 · DOI：10.1016/j.vetpar.2025.110407 · 被引用次数：7 · 研究领域：Insect and Pesticide Research、Plant Virus Research Studies、Vector-borne infectious diseases

Southern cattle tick , Rhipicephalus ( R ) microplus , is a major challenge in transmitting Babesia spp., Theileria spp., and Anaplasma spp., worldwide. Mitigation of this tick and associated pathogens is crucial for animal and human-health. In present study, laboratory-based larval packet tests (LPTs) were performed to assess fipronil efficacy against R . microplus ticks collected from four Chinese localities, Nanning, Guangshui, Macheng, and Tengchong. Additionally, we reported first molecular characterization of the full-length gamma-aminobutyric acid (GABA)-gated chloride channel gene of R . microplus ticks from China and Pakistan (Khyber Pakhtunkhwa and Punjab). For LPTs bioassay, fipronil’s concentrations (5-ppm, 25-ppm, 50-ppm, 75-ppm, 100-ppm) in acetone and DNase-free water were prepared. The highest average mortality rate of larvae was observed in Nanning (4.34–98.13 %) while lowest in Tengchong (5.70–82.29 %) via triplicate LPTs. The recorded LC 50 values were 33.2 ppm, 35.7 ppm, 49.7 ppm, and 55.4 ppm, respectively, for the four localities (Guangshui, Macheng, Nanning, and Tengchong) while the LC 99 values were 722 ppm, 827 ppm, 949 ppm, and 1342.3 ppm, respectively. The resistance factors (RR 50 ) were 13.83, 14.88, 20.71, and 23.08, indicating the development of level-II resistance in the tick populations from these regions respectively. Molecularly, consensus sequences of R . microplus GABA-gene from China and Pakistan resulted 99.24–99.52 % and 99.10–99.39 % id...