van der Heijden Harold M J F, De Gussem Koen, Landman Wil J M
Animal Health Service (GD),Arnsbergstraat 7, 4718 EZ Deventer, the Netherlands.
Tijdschr Diergeneeskd. 2011 Jun 1;136(6):410-6.
Histomonosis, a parasitic disease of galliformes and sporadically of other birds caused by Histomonas meleagridis, can result in very high mortality, especially in turkeys. The ban on the last antihistomonal drug prompted an urgent search for alternative prevention and treatment strategies. As both paromomycin and tiamulin have been reported to have antihistomonal activity, these antibiotics were investigated in vitro by adding two-fold serial dilutions ranging from 12.5 to 400 microg/mL to cultures of H. meleagridis. Controls (no antibiotics, or 12.5 microg or 400 microg/mL dimetridazole) were included. Parasites were counted after 3, 20, 28, 44, 51, and 71 hours of incubation. Tiamulin did not have a clear antihistomonal effect, but paromomycin had an inhibitory effect at all concentrations tested. The latter antibiotic was subsequently examined in an in vivo study. Five groups of 20 1-day-old poults, matched by weight and sex, were either not treated (infected and uninfected control groups) or treated with paromomycin (100, 200, or 400 ppm) added to their feed. After 2 weeks all groups, except for the uninfected control group, were intracloacally inoculated with 200,000 histomonads per bird. A clear dose-response effect was found for paromomycin. In the 100-ppm paromomycin group, mortality was similar to that in the untreated control group, whereas about half of the birds died in the 200-ppm paromomycin group; almost complete protection against histomonosis was seen in the 400-ppm paromomycin group. This study shows that paromomycin supplied in feed at 400 ppm is a potentially preventive strategy against H. meleagridis.
组织滴虫病是一种由火鸡组织滴虫引起的鸡形目禽类寄生虫病，偶尔也会感染其他鸟类，可导致极高的死亡率，尤其是在火鸡中。最后一种抗组织滴虫药物的禁用促使人们迫切寻找替代的预防和治疗策略。由于据报道巴龙霉素和泰妙菌素都具有抗组织滴虫活性，因此通过向火鸡组织滴虫培养物中添加浓度范围为12.5至400μg/mL的两倍系列稀释液，对这些抗生素进行了体外研究。设置了对照组（不添加抗生素，或添加12.5μg或400μg/mL二甲硝唑）。在孵育3、20、28、44、51和71小时后对寄生虫进行计数。泰妙菌素没有明显的抗组织滴虫作用，但巴龙霉素在所有测试浓度下均有抑制作用。随后在一项体内研究中对后一种抗生素进行了检测。将五组每组20只1日龄的雏禽按体重和性别匹配，一组不进行处理（感染和未感染对照组），其余组在饲料中添加巴龙霉素（100、200或400ppm）进行处理。2周后，除未感染对照组外，所有组每只禽经泄殖腔接种200,000个组织滴虫。发现巴龙霉素有明显的剂量反应效应。在100ppm巴龙霉素组中，死亡率与未处理对照组相似，而在200ppm巴龙霉素组中约一半的禽死亡；在400ppm巴龙霉素组中几乎完全预防了组织滴虫病。这项研究表明，在饲料中添加400ppm的巴龙霉素是预防火鸡组织滴虫的一种潜在策略。
