Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa-MG, Cep, Brazil.
Vet Parasitol. 2010 Mar 25;168(3-4):264-8. doi: 10.1016/j.vetpar.2009.11.020. Epub 2009 Dec 2.
The predatory capacity of the nematophagous fungus Pochonia chlamydosporia (isolate VC4) embedded in sodium alginate pellets after passage through the gastrointestinal tract of horses was assessed in vitro against Oxyuris equi eggs. Twelve previously dewormed crossbred mares, average weight of 362.5kg (+/-21) were used in the experiment. Each animal of the treated group received an oral dose (100g) of sodium alginate pellets containing P. chlamydosporia mycelial mass. The control group received pellets without fungus. Faecal samples from fungus-treated and control groups were collected at intervals of 8, 12, 24, 36, 48 and 72h after pellet administration and placed in Petri dishes containing 2% water-agar. One thousand eggs of O. equi were plated in Petri dishes of both treated and control groups, with six replicates, and incubated in oven, 25 degrees C, in the dark, for 30 days. At the end of the experiment, one hundred eggs were removed from each Petri dish and classified according to the following parameters: type 1, physiological and biochemical effect without morphological damage to eggshell, with hyphae adhered to the shell; type 2, lytic effect with morphological change in the eggshell and embryo without hyphal penetration, and type 3, lytic effect with morphological change in the eggshell and embryo, with hyphal penetration and internal egg colonization. Chlamydospore production was observed in Petri dishes of the treated group. The isolate VC4 remained viable after passing through the gastrointestinal tract of horses and maintained the ovicidal activity against O. equi eggs when compared with the control group (p<0.01) after each collection interval: 29.1% (8h), 28.2% (12h), 31.1% (24h), 27.4% (36h), 30.9% (48h) and 28.4% (72h). The results suggest that P. chlamydosporia could be used as an effective biological control agent of O. equi eggs in natural conditions.
经马胃肠道 passage 后嵌入海藻酸钠丸中的捕食性线虫真菌 Pochonia chlamydosporia（分离株 VC4）对马副蛔虫卵的体外捕食能力进行了评估。在实验中，使用了 12 匹先前驱虫的杂交母马，平均体重为 362.5kg（+/-21）。处理组的每只动物都口服（100g）含有 P. chlamydosporia 菌丝体质量的海藻酸钠丸。对照组接受不含真菌的丸剂。在丸剂给药后 8、12、24、36、48 和 72 小时，从真菌处理组和对照组采集粪便样本，并将其放置在含有 2%水琼脂的培养皿中。将 1000 个马副蛔虫卵接种到处理组和对照组的培养皿中，每组 6 个重复，并在 25°C 的黑暗烘箱中孵育 30 天。实验结束时，从每个培养皿中取出 100 个卵，并根据以下参数进行分类：1 型，无卵壳形态损伤的生理生化效应，有菌丝附着在壳上；2 型，卵壳和胚胎形态变化的裂解效应，无菌丝穿透，3 型，卵壳和胚胎形态变化的裂解效应，有菌丝穿透和内部卵定植。在处理组的培养皿中观察到了 chlamydospore 的产生。与对照组相比（p<0.01），分离株 VC4 经马胃肠道 passage 后仍具有活力，并在每个采集间隔（8h：29.1%；12h：28.2%；24h：31.1%；36h：27.4%；48h：30.9%；72h：28.4%）保持对 O. equi 卵的杀卵活性。结果表明，P. chlamydosporia 可作为一种有效的 O. equi 卵自然条件下的生物防治剂。
