Isolation of Arthrobotrys oligospora from soil of the Chinese Northern Tianshan Mountain slope pasture show predatory ability against Haemonchus contortus larvae

To understand the biocontrol ability of Arthrobotrys oligospora isolated from the Northern Tianshan Mountain slope pasture, Xinjiang region, China, on livestock gastrointestinal nematode diseases, we acquired 68 soil samples and isolated 26 nematode-trapping fungi using Haemonchus contortus L₃. Eight isolates were identified based on their morphological and molecular identification. The predacious activity against H. contortus was detected before and after passage through the sheep gastrointestinal tract. As a result, these eight isolates were identified as A. oligospora. They displayed predacious activities ranging from 90% to 97%. Six of the isolates could pass through the sheep gastrointestinal tract significantly reducing the number of H. contortus larvae by 76–79%. This study shows that A. oligospora isolated from the northern slope pasture of Tianshan Mountain has high predacious activity against H. contortus larvae and partly passing through the sheep gastrointestinal tract. This study also shows that conidial suspensions have no toxic side-effects on the sheep, indicating that they have the potential for the development of oral biological agents which prevent and control livestock gastrointestinal nematode diseases.