Williams Heike, Young David R, Qureshi Tariq, Zoller Hartmut, Heckeroth Anja R
MSD Animal Health Innovation GmbH, Research Antiparasitics, Zur Propstei, 55270 Schwabenheim, Germany.
Parasit Vectors. 2014 Jun 19;7:275. doi: 10.1186/1756-3305-7-275.
Fluralaner, a novel isoxazoline, has both acaricidal and insecticidal activity through potent blockage of GABA- and L-glutamate-gated chloride channels. This study investigated the in vitro and in vivo effects of fluralaner exposure on flea (Ctenocephalides felis) reproduction.
Blood spiked with sub-insecticidal fluralaner concentrations (between 0.09 and 50.0 ng/mL) was fed to fleas for 10 days using a membrane system. Cessation of reproduction in exposed fleas was assessed using flea survival, egg hatchability, and control of oviposition, pupae, and flea emergence. Fluralaner efficacy for in vivo Ctenocephalides (C.) felis control on dogs was assessed using a simulated flea-infested home environment. During a pre-treatment period, dogs were infested twice on days -28 and -21 with 100 adult unfed fleas to establish a thriving population by day 0 of the study. On day 0, one group of dogs was treated with fluralaner (Bravecto™; n=10), while another group served as negative control (n=10). Following treatment, dogs were infested three times with 50 fleas on days 22, 50 and 78 to simulate new infestations. Live flea counts were conducted weekly on all dogs for 12 weeks starting 1 day before treatment.
Fluralaner potently inhibited flea reproduction capacity in vitro. Oviposition ceased completely at concentrations as low as 25.0 ng/mL. While no ovicidal effect was observed, fluralaner exerted a larvicidal effect at exceptionally low concentrations (6.25 ng/mL). In the simulated flea-infested home environment, flea-control efficacy on fluralaner-treated dogs was >99% at every time point measured for 12 weeks. No adverse events were observed in fluralaner-treated dogs.
Fluralaner completely controls egg laying, larval development and flea reproduction even at sub-insecticidal concentrations. Oral treatment of dogs with fluralaner is highly effective for eliminating fleas in a simulated flea-infested home environment.
氟虫腈是一种新型异恶唑啉,通过有效阻断γ-氨基丁酸(GABA)和L-谷氨酸门控氯离子通道而具有杀螨和杀虫活性。本研究调查了氟虫腈暴露对跳蚤(猫栉首蚤)繁殖的体外和体内影响。
使用膜系统将添加了亚杀虫浓度(0.09至50.0纳克/毫升)氟虫腈的血液喂给跳蚤10天。通过跳蚤存活率、卵孵化率以及对产卵、蛹和跳蚤羽化的控制来评估暴露跳蚤繁殖的停止情况。在模拟跳蚤滋生的家庭环境中评估氟虫腈对犬体内猫栉首蚤的控制效果。在预处理期间,犬在第-28天和第-21天两次感染100只未进食的成年跳蚤,以便在研究第0天建立一个繁荣的跳蚤种群。在第0天,一组犬用氟虫腈(拜宠爽™;n = 10)治疗,而另一组作为阴性对照(n = 10)。治疗后,犬在第22天、第50天和第78天三次感染50只跳蚤以模拟新的感染。从治疗前1天开始,对所有犬每周进行一次活跳蚤计数,持续12周。
氟虫腈在体外能有效抑制跳蚤繁殖能力。在低至25.0纳克/毫升的浓度下产卵完全停止。虽然未观察到杀卵作用,但氟虫腈在极低浓度(6.25纳克/毫升)下具有杀幼虫作用。在模拟跳蚤滋生的家庭环境中,在测量的12周内的每个时间点,氟虫腈治疗的犬的跳蚤控制效果均>99%。在氟虫腈治疗的犬中未观察到不良事件。
即使在亚杀虫浓度下,氟虫腈也能完全控制产卵、幼虫发育和跳蚤繁殖。用氟虫腈口服治疗犬对在模拟跳蚤滋生的家庭环境中消除跳蚤非常有效。