Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA; Grupo de Parasitología Veterinaria, Universidad Nacional de Colombia, Colombia.
TRS Labs, Inc, Athens, GA, USA.
Int J Parasitol Drugs Drug Resist. 2020 Aug;13:22-27. doi: 10.1016/j.ijpddr.2020.04.003. Epub 2020 Apr 20.
Ancylostoma caninum is the most prevalent intestinal nematode of dogs, and has a zoonotic potential. Multiple-drug resistance (MDR) has been confirmed in a number of A. caninum isolates, including isolate Worthy 4.1F3P, against all anthelmintic drug classes approved for hookworm treatment in dogs in the United States (US). The cyclooctadepsipeptide emodepside is not registered to use in dogs in the US, but in a number of other countries/regions. The objective of this study was to evaluate the efficacy of emodepside + praziquantel, as well as three commercial products that are commonly used in the US for treatment of hookworms, against a suspected (subsequently confirmed) MDR A. caninum isolate Worthy 4.1F3P. 40 dogs infected on study day (SD) 0 with 300 third-stage larvae, were randomly allocated to one of five treatment groups with eight dogs each: pyrantel pamoate (Nemex®-2), fenbendazole (Panacur® C), milbemycin oxime (Interceptor®), emodepside + praziquantel tablets and non-treated control. Fecal egg counts (FEC) were performed on SDs 19, 20, 22, 27, 31 and 34. All treatments were administered as per label requirements on SD 24 to dogs in Groups 1 through 4. Two additional treatments were administered on SDs 25 and 26 to dogs in Group 2 as per label requirements. Dogs were necropsied on SD 34 and the digestive tract was removed/processed for worm recovery and enumeration. The geometric mean (GM) worm counts for the control group was 97.4, and for the pyrantel pamoate, fenbendazole, milbemycin oxime, and emodepside + praziquantel groups were 74.8, 72.0, 88.9, and 0.4, respectively. These yielded efficacies of 23.2%, 26.1%, and 8.8%, and 99.6%, respectively. These data support previous findings of the MDR status of Worthy 4.1F3P as treatments with pyrantel pamoate, fenbendazole and milbemycin oxime lacked efficacy. In sharp contrast, Worthy 4.1F3P was highly susceptible to treatment with emodepside + praziquantel.
犬钩虫是犬类最常见的肠道线虫，具有潜在的人畜共患性。已经确认了许多犬钩虫分离株具有多重耐药性（MDR），包括 Worthy 4.1F3P 分离株，这些分离株对美国批准用于治疗犬钩虫的所有驱虫药类别均具有耐药性。环八肽驱虫药埃莫康唑在美国尚未注册用于犬类，但在许多其他国家/地区有注册。本研究的目的是评估埃莫康唑+吡喹酮以及三种在美国常用于治疗钩虫的商业产品对疑似（随后证实）MDR 犬钩虫分离株 Worthy 4.1F3P 的疗效。40 只在研究日（SD）0 感染 300 条第三期幼虫的犬被随机分配到五个治疗组中的一个，每组 8 只：双羟萘酸噻嘧啶（Nemex®-2）、芬苯达唑（Panacur® C）、米尔贝肟（Interceptor®）、埃莫康唑+吡喹酮片和未治疗对照组。在 SD 19、20、22、27、31 和 34 进行粪便卵计数（FEC）。根据标签要求，所有治疗组（第 1 组至第 4 组）的犬均在 SD 24 进行治疗。根据标签要求，第 2 组的犬在 SD 25 和 26 进行了另外两次治疗。在 SD 34 对犬进行剖检，取出/处理消化道以回收和计数蠕虫。对照组的几何均数（GM）虫数为 97.4，双羟萘酸噻嘧啶、芬苯达唑、米尔贝肟和埃莫康唑+吡喹酮组分别为 74.8、72.0、88.9 和 0.4。这些治疗的疗效分别为 23.2%、26.1%、8.8%和 99.6%。这些数据支持 Worthy 4.1F3P 的 MDR 状态的先前发现，即双羟萘酸噻嘧啶、芬苯达唑和米尔贝肟治疗缺乏疗效。相比之下，Worthy 4.1F3P 对埃莫康唑+吡喹酮的治疗非常敏感。
