Sarli Macarena, Torrents Jorgelina, Morel Nicolás, Nava Santiago
Instituto de Investigación de la Cadena Láctea (IdICaL) (INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), CP 2300 Rafaela, Santa Fe, Argentina.
Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Kreder 2805, CP 3080 Esperanza, Santa Fe, Argentina.
Ticks Tick Borne Dis. 2022 Nov;13(6):102030. doi: 10.1016/j.ttbdis.2022.102030. Epub 2022 Aug 22.
This study aimed to evaluate the sequence variations of the GABA-Cl gene of Rhipicephalus (Boophilus) microplus ticks from Argentina with different resistance levels to fipronil. Genomic DNA was obtained from engorged females (n = 50) of fipronil-susceptible and resistant tick field populations from five localities in northern Argentina. Tick populations were tested for fipronil resistance by in vitro larval packet test. DNA encoding amino acid residues 264-360 of the GABA-Cl was amplified by PCR. PCR products were sequenced and the translated amino acid sequences were aligned and compared among each other and with sequences of the GABA-Cl belonging to the Brazilian and Uruguayan reference strains fipronil-susceptible (Mozo) and resistant (RFSan and Juarez). All the GABA-Cl amino acid sequences obtained from the R. microplus specimens from Argentina were identical, regardless of the fipronil resistance-susceptibility status of each population. Mutations present in GABA-Cl sequence of RFSan and Juarez strains were not present in any of the populations from Argentina analyzed. These results indicate the failure of this gene as a molecular marker of resistance to fipronil, at least in the R. microplus populations from northern Argentina.
本研究旨在评估来自阿根廷的对氟虫腈具有不同抗性水平的微小牛蜱（Rhipicephalus (Boophilus) microplus）的GABA-Cl基因的序列变异。从阿根廷北部五个地区的氟虫腈敏感和抗性蜱虫野外种群的饱血雌蜱（n = 50）中获取基因组DNA。通过体外幼虫包囊试验检测蜱虫种群对氟虫腈的抗性。通过PCR扩增编码GABA-Cl第264 - 360位氨基酸残基的DNA。对PCR产物进行测序，并将翻译后的氨基酸序列相互比对，并与属于巴西和乌拉圭参考菌株氟虫腈敏感型（Mozo）和抗性型（RFSan和Juarez） 的GABA-Cl序列进行比较。从阿根廷微小牛蜱样本中获得的所有GABA-Cl氨基酸序列均相同，无论每个种群对氟虫腈的抗性敏感状态如何。在RFSan和Juarez菌株的GABA-Cl序列中存在的突变在所分析的任何阿根廷种群中均未出现。这些结果表明，该基因作为对氟虫腈抗性的分子标记失败，至少在阿根廷北部的微小牛蜱种群中是这样。
