Postgraduate Program in Veterinary Medicine, Federal University of Santa Maria, S. Maria, Brazil.
Parasitol Res. 2012 Feb;110(2):657-62. doi: 10.1007/s00436-011-2537-7. Epub 2011 Jul 12.
Biological control is an alternative method to reduce the population of parasites through natural predators. A promising option of biological control in the reduction of infective larvae on pasture is the use of nematophagous fungi. In this study, the efficacy of the nematophagous fungus Duddingtonia flagrans in controlling gastrointestinal nematode parasites in field-raised horses was tested. Ten foals with an average age of 12 months were divided in two groups: five males constituted the treated group and five females constituted the control group. Each group was introduced in a field of mixed pasture with approximately 5 ha. The treated group received the fungus D. flagrans at a concentration of 10(6) chlamydospores per kilogramme of animal body weight daily, mixed with horse food for 5 months. The control group did not receive the fungus. Samples were collected to perform eggs per gramme (EPG) counts weekly. Coproculture and collection of pasture were done monthly for larvae counting. No significant difference was observed in the EPG counting and in the number of larvae recovered from coprocultures, where cyathostomines, Strongylus and Trichostrongylus spp. were found after monthly larvae counting. No significant difference was observed in the EPG counts, and Trichostrongylus sp. was identified. The number of recovered larvae on pasture was significantly lower in the treated group in the last month of treatment, showing a reduction of 73.5% (p < 0.05). As such, the fungus was able to reduce the number of infective larvae in the pasture. Nevertheless, this did not reflect in a decrease of parasitic infection during the 5-month study period.
生物防治是一种通过自然捕食者来减少寄生虫数量的替代方法。在减少牧场上感染性幼虫方面，利用食线虫真菌是一种很有前途的生物防治选择。在这项研究中，测试了捕食性真菌 Duddingtonia flagrans 控制野外饲养马胃肠道线虫寄生虫的功效。10 匹平均年龄为 12 个月的小马被分为两组：5 匹公马为处理组，5 匹母马为对照组。每组被引入约 5 公顷的混合牧场上。处理组每天接受浓度为 10(6)个分生孢子/公斤动物体重的真菌 D. flagrans，与马饲料混合 5 个月。对照组未接受真菌。每周收集样本进行每克卵（EPG）计数。每月进行粪便培养和收集牧草以进行幼虫计数。在 EPG 计数和从粪便培养中回收的幼虫数量方面没有观察到显著差异，每月进行幼虫计数后发现了Cyathostomines、Strongylus 和 Trichostrongylus spp。在 EPG 计数方面没有观察到显著差异，并且鉴定出了 Trichostrongylus sp。在治疗的最后一个月，处理组牧场上回收的幼虫数量明显较低，减少了 73.5%（p<0.05）。因此，真菌能够减少牧场上的感染性幼虫数量。然而，这并没有反映在为期 5 个月的研究期间寄生虫感染的减少。
