Bezerra-Santos Marcos Antonio, Dantas-Torres Filipe, Pugliese Nicola, Miglianti Mara, Rhimi Wafa, Cafarchia Claudia, Otranto Domenico
Department of Veterinary Medicine, University of Bari, Italy.
Aggeu Magalhães Institute, Fundação Oswaldo Cruz (Fiocruz), Recife, Brazil.
Ticks Tick Borne Dis. 2025 Jul;16(4):102493. doi: 10.1016/j.ttbdis.2025.102493. Epub 2025 Jun 7.
Brown dog ticks (Rhipicephalus sanguineus sensu lato) are widespread ectoparasites of dogs and may also infest other vertebrate hosts, including humans. The control of these ticks is primarily carried out using acaricides. In this study, we assessed the susceptibility of Rhipicephalus rutilus to different acaricides (i.e., amitraz, fipronil, ivermectin, and permethrin). Engorged female ticks (n = 36) were divided into three groups based on their origin (i.e., G1 - untreated dogs from a private shelter; G2 - permethrin-treated private dog shelter; and G3 - fipronil, amitraz, and (S)-methoprene treated owned dogs) and kept under controlled temperature and humidity for oviposition. The acaricidal effects of amitraz (AMZ), fipronil (FIP), ivermectin (IVM), and permethrin (PTR) against R. rutilus were evaluated using the larval packet test, with subgroups of tick larvae in each experimental assay. Our data indicate that R. rutilus larvae from all dog groups were susceptible to IVM. In particular, larvae from G1 were apparently susceptible to IVM and PTR, and tolerant to AMZ and FIP; larvae from G2 were susceptible to FIP and IVM and resistant to AMZ and PTR, while larvae from G3 were susceptible to AMZ, PTR and IVM, and resistant to FIP. These results confirm the occurrence of resistance to AMZ, PTR, and FIP in R. rutilus larvae from southern Italy. This suggests the need to monitor acaricide resistance in brown dog ticks in southern Europe to develop better strategies for the long-term control of ticks in this region.
棕狗蜱（广义血红扇头蜱）是广泛存在于犬类身上的体外寄生虫，也可能侵袭包括人类在内的其他脊椎动物宿主。对这些蜱的控制主要使用杀螨剂。在本研究中，我们评估了红棕硬蜱对不同杀螨剂（即双甲脒、氟虫腈、伊维菌素和氯菊酯）的敏感性。饱血雌蜱（n = 36）根据其来源分为三组（即G1 - 来自私人庇护所的未处理犬；G2 - 用氯菊酯处理过的私人犬庇护所；以及G3 - 用氟虫腈、双甲脒和（S）-烯虫酯处理过的自有犬），并在可控的温度和湿度下饲养以进行产卵。使用幼虫包囊试验评估双甲脒（AMZ）、氟虫腈（FIP）、伊维菌素（IVM）和氯菊酯（PTR）对红棕硬蜱的杀螨效果，每个实验测定中都有蜱幼虫亚组。我们的数据表明，所有犬组的红棕硬蜱幼虫对IVM敏感。特别是，G1组的幼虫显然对IVM和PTR敏感，对AMZ和FIP耐受；G2组的幼虫对FIP和IVM敏感，对AMZ和PTR耐药，而G3组的幼虫对AMZ、PTR和IVM敏感，对FIP耐药。这些结果证实了意大利南部红棕硬蜱幼虫对AMZ、PTR和FIP存在抗性。这表明需要监测南欧棕狗蜱的杀螨剂抗性，以制定该地区蜱长期控制的更好策略。
