Castro Janer E, Klafke G M, Capurro M L, Schumaker T T S
Department of Parasitology, School of Veterinary-UDELAR, Av. Lasplaces 1620, CP 1600, Montevideo, Uruguay; Department of Parasitology, Instituto de Ciências Biomédicas-USP, Av. Prof. Lineu Prestes 1374, CEP 05508000, São Paulo, SP, Brazil.
Laboratory of Parasitology, FEPAGRO Animal Health, Eldorado do Sul, RS, Brazil.
Vet Parasitol. 2015 May 30;210(1-2):77-83. doi: 10.1016/j.vetpar.2015.03.011. Epub 2015 Mar 26.
The southern cattle tick, Rhipicephalus (Boophilus) microplus (Canestrini), is one of the most damaging parasites of cattle in tropical and subtropical regions. Several chemical groups have been used for its control, including cyclodienes (lindane and dieldrin). In Uruguay and Brazil these products were used at the beginning of the 1960s and during a few years. Fipronil and lindane act on the same target site. In both countries, southern cattle tick resistance to fipronil has sometimes developed quickly after only a few acaricide treatments (three to seven). The objective of the present study was to determine cross-resistance between fipronil and lindane in southern cattle ticks from Uruguay and Brazil. Initially, the FAO's (Food and Agricultural Organization) larval packet test with lindane was applied to a fipronil-resistant strain and to susceptible field populations. Mozo and POA strains were used as the susceptible controls. A larval immersion test was used to assess fipronil toxicity. Of fifteen fipronil-resistant field populations that were tested with lindane, eleven were lindane-resistant and three were susceptible. The last three populations had incipient resistance to fipronil. Finally, cross-resistance between fipronil and lindane in the southern cattle tick is reported in this study for the first time.
南方牛蜱，微小扇头蜱（Rhipicephalus (Boophilus) microplus (Canestrini)），是热带和亚热带地区对牛危害最大的寄生虫之一。已有多种化学药剂用于控制这种蜱虫，包括环二烯类（林丹和狄氏剂）。在乌拉圭和巴西，这些产品于20世纪60年代初使用了数年。氟虫腈和林丹作用于相同的靶位点。在这两个国家，南方牛蜱对氟虫腈的抗性有时在仅经过几次杀螨剂处理（三至七次）后就迅速产生。本研究的目的是确定乌拉圭和巴西南方牛蜱对氟虫腈和林丹之间的交叉抗性。最初，将粮农组织（Food and Agricultural Organization）的林丹幼虫药包试验应用于一个对氟虫腈有抗性的品系和易感的田间种群。莫佐（Mozo）品系和POA品系用作易感对照。采用幼虫浸液试验评估氟虫腈的毒性。在用林丹测试的15个对氟虫腈有抗性的田间种群中，11个对林丹有抗性，3个易感。最后这三个种群对氟虫腈有初期抗性。本研究首次报道了南方牛蜱对氟虫腈和林丹之间的交叉抗性。
