Internal Medicine, Faculty of Veterinary Medicine, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Spain.
Group GIR of animal and human dirofilariosis, Laboratory of Parasitology, Faculty of Pharmacy, University of Salamanca, Salamanca, Spain.
Vet Parasitol. 2020 Jul;283:109141. doi: 10.1016/j.vetpar.2020.109141. Epub 2020 Jun 2.
The endosymbiont bacteria Wolbachia plays an important role in the pathogenesis and inflammatory immune response to heartworm (Dirofilaria immitis) infection in dogs. Doxycycline is used to reduce Wolbachia from all life stages of heartworm to avoid large releases of the bacteria during the death of the worms. However, the dose and duration currently recommended have been extrapolated from the treatment of other rickettsial infections. Therefore, the aim was to study the dynamics of Wolbachia IgG antibodies in heartworm-infected dogs under adulticide treatment using different dosages of doxycycline. Forty-nine heartworm-infected dogs were recruited. On day 0 (diagnosis), monthly ivermectin (6 μg/kg) was prescribed, as well as daily doxycycline for 30 days, at 10 mg/kg/12 h (n = 13), 5 mg/kg/12 h (n = 19), and 10 mg/kg/24 h (n = 17). Dogs underwent adulticide treatment and blood samples were collected on days 0, 30, 90, and 120. All dogs had antibodies against recombinant Wolbachia surface protein (rWSP), confirming the important role of the bacteria in heartworm. No significant differences were found in anti-rWSP response by presence/absence of microfilariae, or by parasite burden on day 0. In all treated groups, the anti-rWSP antibody response was not significantly different between days 0 and 30 but was significantly lower between days 0 and 120 (p < 0.05). The results of the present study suggest that the administration of a lower dose than currently recommended is sufficient to achieve a significant reduction of Wolbachia in dogs infected by D. immitis.
共生菌沃尔巴克氏体在犬心丝虫（Dirofilaria immitis）感染的发病机制和炎症免疫反应中起重要作用。多西环素用于减少心丝虫所有生活阶段的沃尔巴克氏体，以避免在蠕虫死亡时大量释放细菌。然而，目前推荐的剂量和持续时间是从其他立克次体感染的治疗中推断出来的。因此，本研究旨在研究使用不同剂量多西环素治疗杀成虫剂治疗下心丝虫感染犬中沃尔巴克氏体 IgG 抗体的动态变化。招募了 49 只心丝虫感染犬。在第 0 天（诊断），每月给予伊维菌素（6μg/kg），并连续 30 天每天给予多西环素，剂量分别为 10mg/kg/12h（n=13）、5mg/kg/12h（n=19）和 10mg/kg/24h（n=17）。犬接受杀成虫剂治疗，并在第 0、30、90 和 120 天采集血液样本。所有犬均对重组沃尔巴克氏体表面蛋白（rWSP）产生抗体，证实了细菌在心丝虫病中的重要作用。在第 0 天，无论是否存在微丝蚴或寄生虫负荷，抗 rWSP 反应均无差异。在所有治疗组中，第 0 天和第 30 天之间的抗 rWSP 抗体反应无显著差异，但第 0 天和第 120 天之间的差异有统计学意义（p<0.05）。本研究结果表明，给予低于目前推荐剂量的剂量足以显著减少犬感染犬心丝虫的沃尔巴克氏体。
