Área de Parasitología y Enfermedades Parasitarias, Centro de Investigación Veterinaria de Tandil (CIVETAN) (CONICET-UNCPBA-CICPBA), Facultad de Ciencias Veterinarias, UNCPBA, Tandil, Argentina.
Área de Parasitología y Enfermedades Parasitarias, Centro de Investigación Veterinaria de Tandil (CIVETAN) (CONICET-UNCPBA-CICPBA), Facultad de Ciencias Veterinarias, UNCPBA, Tandil, Argentina.
Exp Parasitol. 2021 Nov;230:108156. doi: 10.1016/j.exppara.2021.108156. Epub 2021 Sep 14.
The nematophagous fungus Duddingtonia flagrans, used for the biological control of gastrointestinal nematodes in livestock, is fed to infected animals so its chlamydospores and the parasite eggs are voided together with faeces where the fungus preys on nematode larvae, thus reducing pasture infectivity. The number of chlamydospores needed for the fungus to be efficient in the presence of a wide range in numbers of parasitic eggs is largely unknown and a matter of discussion. The aim of this study was to determine the fungal efficacy of four different chlamydospore concentrations against three different levels of cattle faecal egg counts. Fungal concentrations of 11000, 6250, 3000 and 1000 chlamydospores/gram of faeces (cpg) were added to cultures containing 840, 480 or 100 eggs/gram of faeces (epg). After 14 days of incubation, the efficacy of D. flagrans, in decreasing order of chlamydospore concentrations, ranged from 100% (P < 0.0001) to 77% (P > 0.0999) in the 100 epg groups; 100% (P < 0.0001) to 92% (P = 0.4625) in the 480 epg groups and 100% (P < 0.0001) to 96% (P = 0.7081) in the 840 epg groups. The results indicate that the numbers of eggs in cattle faeces were not a determining factor on the fungal efficacy against gastrointestinal nematodes.
寄生性真菌杜氏藻（Duddingtonia flagrans）用于生物防治家畜的胃肠道线虫，将其喂给感染动物，使它的厚垣孢子和寄生虫卵一起随粪便排出，在那里真菌捕食线虫幼虫，从而降低牧场的感染力。在存在大量寄生虫卵数量的情况下，真菌需要多少厚垣孢子才能有效，这在很大程度上是未知的，也是讨论的一个问题。本研究的目的是确定四种不同厚垣孢子浓度对三种不同牛粪便卵计数水平的真菌疗效。将浓度为 11000、6250、3000 和 1000 厚垣孢子/克粪便（cpg）的真菌添加到含有 840、480 或 100 个卵/克粪便（epg）的培养物中。孵育 14 天后，杜氏藻的疗效按厚垣孢子浓度降序排列，在 100 epg 组中从 100%（P<0.0001）到 77%（P>0.0999）不等；在 480 epg 组中从 100%（P<0.0001）到 92%（P=0.4625）不等；在 840 epg 组中从 100%（P<0.0001）到 96%（P=0.7081）不等。结果表明，牛粪便中的卵数不是影响真菌对胃肠道线虫疗效的决定因素。
