Nematophagous fungi for biological control of gastrointestinal nematodes in domestic animals

Abstract

Several studies have been conducted using fungi in the biological control of domestic animals and humans. In this respect, a large amount of research has been undertaken to understand the particularities of each fungus used. These fungi have been demonstrated to act on all classes of helminthes. Therefore, they should not only be called nematophagous but also helmintophagous. Evidence of enzymatic action has also revealed their mechanism of action, as well as potential metabolites that could be synthesized as bioactive molecules. Cultural barriers to the use of fungi should be broken down, since the impact on the environment is minimal. In this context, much is already known about the mechanism of interaction of these organisms with their 'targets'. Recent research has pointed to the search for substances derived from nematophagous fungi that have demonstrated their ovicidal and/or larvicidal activity, thus being a global premise to be studied further. Crude extracts derived from nematophagous fungi of predator and ovicidal groups reduce the amount of larvae of gastrointestinal nematodes and prevent the hatching of their eggs, since they have been demonstrated to act with extracellular proteases and other enzymes. Furthermore, the activity of these enzymes has begun to be explored regarding their possible interaction with the exoskeleton of arthropods, which could emerge as an alternative method of tick control. Finally, it should be clear that nematophagous fungi in general are 'old friends' that are ready to the 'fight with our old enemies', the gastrointestinal helminth parasites harmful to human and animal health.

Predatory Activity of the Fungus Pleurotus eryngii on Ancylostoma caninum Infective Larvae

“…In a study by Larsen and Nansen [13], L3 of different nematodes (Ostertagia ostertagi, Cooperia oncophora, Oesophagostomum quadrispinulatum and Cyathostomum species) tended to distort the mycelium of the fungus P. pulmonarius by vigorous movement and after three or four hours the larvae were gathered around the periphery of the petri dishes where they were difficult to identify and count as movable or immovable, with data being recorded along the first three or four hours of exposure. This larval migration to the periphery of the plate where there is more moisture was also observed by Carvalho et al [6] e Braga e Araujo [19].…”

“…It is estimated that about 1 billion people are currently infected with geohelminths, mainly due to contact with the soil, indicating that this is an important route of human infection, which is associated with serious health consequences if untreated [19]. Furthermore, studies on parasites that infect domestic animals have caused great interest due to the close relationship between man and animals, which may be a public health problem.…”

“…Therefore, it is necessary to know the role of all organisms involved in the biocontrol of nematodes [19]. According to Araújo et al [5] it is essential that funding agencies support research in this area because many basic aspects of biology, epidemiology and host-pathogen interaction need to be studied.…”

Extracellular biosynthesis of silver nanoparticles using the cell-free filtrate of nematophagous fungus <em>Duddingtonia flagrans</em>

“…In addition, it is harmless to animal and human health and to the environment. 17,18 In the crude extract of D. flagrans, extracellular enzymes can be identified, such as proteases and chitinases, capable of hydrolyzing the nematode cuticle, which facilitate predation of the parasite. Therefore, its applicability has been studied extensively.…”

Capacidad predadora in vitro de hongos nematófagos nativos de Cundinamarca sobre nematodos gastrointestinales de bovinos

“…Se sembraron 60 muestras de suelo de fincas ganaderas en cajas de Petri con medio agar-agua para el atrapamiento de los hongos, y se identificaron mediante claves morfométricas tres cepas del hongo Arthrobotrys oligospora (L1, XVIII y XXI) y una de Arthrobotrys musiformis (XXIV). Se utilizaron 1 × 10 6 conidios o clamidosporas de cada hongo, los cuales se enfrentaron a 100 larvas de nematodos. El aislamiento XXIV (A. musiformis) demostró mayor capacidad predadora (96,8 %) que los aislamientos (A. oligospora) XVIII, L1 y XXI (69, 68, 71,1 y 87,62 %, respectivamente).…”