Predatory activity of nematophagus fungus Duddingtonia flagrans in infective larvae after gastrointestinal transit: biological control in pasture areas and in vitro

Abstract

Biological control is a strategy to decrease parasitic populations, and the action takes place through natural antagonists in the environment. We studied the predatory activity of the fungus Duddingtonia flagrans in infective larvae (L3) of gastrointestinal nematodes after gastrointestinal transit. Ten heifers were divided into two groups: treated (animals received pellets containing fungus) and control (animals received pellets without fungus). Twelve hours after administration, faeces samples were collected for in vitro efficacy tests. The animals then remained for 7 h in the experimental pasture area. At the end of this period, 20 faecal pads (ten treated and ten control) were selected at random. Pasture, faecal pad and soil collections occurred with an interval of 7 days, totalling four assessments. In vitro activity demonstrated that fungi effectively preyed on L3, achieving a reduction percentage of 88%. In the faecal pad of the pasture area, there was a difference (P < 0.05) between collections 3 and 4 for both groups; in the treated group a reduction of 65% was obtained, while in the control group there was an increase of 217% in the number of L3. The recovery of L3 in the soil and in the pasture was similar in both groups. There was no influence (P = 0.87) of the passage time on the fungus predatory activity. Duddingtonia flagrans demonstrated the ability to survive gastrointestinal transit in the animals, reducing the number of L3 in the faeces, indicating that this biological control has great potential in the control of worm infections.

Recent Advances in the Control of Helminths of Domestic Animals by Helminthophagous Fungi

“…The use of biological control by helminthophagous fungi provides an option to reduce the rates of contamination by larvae and, consequently, less reinfection for the animals, enabling them to develop natural immunity against the helminths. In addition, animals that receive helminthophagous fungi have higher weight gain rates, higher globular volume percentages, and lower EPG values when compared to those that do not receive the fungi [5,[67][68][69][70]. In grazing horses that received D. flagrans chlamydospores daily, strongylide counts below 200 EPG were obtained for 16 months, also verifying that they recovered normal blood values of erythrocytes, hemoglobin, and hematocrit [71].…”

Efficacy of a Fungal Formulation with the Nematophagous Fungus Pochonia chlamydosporia in the Biological Control of Bovine Nematodiosis

“…Using this knowledge, prophylactic measures can be used for effective control, reducing the use of chemicals, cases of anthelmintic resistance, and dependence on the use of anthelmintics, when associated with other control methods. One of these methods is biological control by nematophagous fungi [4].…”

Control of sheep gastrointestinal nematodes on pasture in the tropical semiarid region of Brazil, using Bioverm® (Duddingtonia flagrans)

“…This fungus produces an abundant amount of chlamydospores, which are highly resistant structures that when ingested resist digestion and pass through the gastrointestinal tract of animals (Larsen et al, 1992). After elimination with feces, they are capable of germinating and destroying the infecting larvae, thus interrupting the life cycle of the parasite in the environment (Araújo et al, 2021;Baiak et al 2021).…”