Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Kreder 2805, CP 3080, Esperanza, Santa Fe, Argentina.
Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela, CC 22, CP 2300, Rafaela, Santa Fe, Argentina.
Exp Appl Acarol. 2020 Nov;82(3):397-403. doi: 10.1007/s10493-020-00554-7. Epub 2020 Sep 30.
The aim of this work was to adapt and apply the in vitro larval bioassay packet test (LPT) to diagnose resistance of Rhipicephalus microplus ticks to fipronil in Argentina. Ten serial dilutions of fipronil were included in the LPT bioassay. Seven populations of R. microplus from six Argentinean Provinces were evaluated. Samples from Colonia Benítez, Quimilí and Intiyaco were unambiguously classified in the category 'resistant'. In all these cases the 95% confidence intervals did not overlap with that of the susceptible reference strain and the slope values were lower than the slope value obtained for the susceptible reference strain. The resistance ratio (RR) values of the populations from Colonia Benítez I and II, Quimilí and Intiyaco were 2.23, 3.49, 6.84 and 3.39, respectively. Populations from El Colorado I and II, Acambuco, Vera and Feliciano were classified as 'susceptible' because the 95% confidence intervals overlapped with that of the susceptible reference strain and the RR values never exceeded 1.32. The results of these LPT bioassays indicate the presence of fipronil resistant R. microplus populations in Argentina.
本研究旨在改编和应用体外幼虫生物测定试剂盒试验（LPT）来诊断阿根廷里氏血蜱对氟虫腈的抗性。LPT 生物测定中包含了氟虫腈的十个连续稀释浓度。评估了来自阿根廷六个省份的七个里氏血蜱种群。来自科洛尼亚贝尼特斯、基米利和因蒂亚科的样本被明确归类为“抗性”。在所有这些情况下，95%置信区间与敏感参考株的置信区间不重叠，斜率值低于敏感参考株的斜率值。来自科洛尼亚贝尼特斯 I 和 II、基米利和因蒂亚科的种群的抗性比（RR）值分别为 2.23、3.49、6.84 和 3.39。来自埃尔科罗迪奥 I 和 II、阿坎布科、维拉和费利西亚诺的种群被归类为“敏感”，因为 95%置信区间与敏感参考株的置信区间重叠，RR 值从未超过 1.32。这些 LPT 生物测定的结果表明，阿根廷存在对氟虫腈具有抗性的里氏血蜱种群。
