[Nematophagous fungi used for the biological control of gastrointestinal nematodes in livestock and administration routes].

The control of gastrointestinal nematodes relies at present mostly on antihelmintic treatments using synthetic molecules. This approach, however, has led to the appearance of resistance to some types of antihelmintics which, together with the need to cut down on the use of chemicals, has fostered the development of other control methods, such as biological control, which is the use of living organisms that are naturally antagonistic to an unwanted species. Among the natural enemies of nematode parasitic larvae is the microfungus Duddingtonia flagrans. Research has shown the ability of this fungus to reduce the number of nematode larvae in faeces, the ability of its chlamydospores to survive the passage through the gastrointestinal tract of livestock and, moreover, to keep its germinative ability, thus facilitating the development of formulations. The present review looks at the species currently used and the different ways of administering already tested nematophagous fungi.