Ovicidal activity of seven Pochonia chlamydosporia fungal isolates on Ascaris suum eggs

Abstract

The ovicidal effect of the nematophagous fungus Pochonia chlamydosporia on eggs of Ascaris suum was tested under laboratory conditions. A. suum eggs were plated on 2% water-agar with seven fungal isolates (Isol. 5, Isol. 31, Isol. 1, VC1, Isol. 12, Isol. 22 and VC4) and control without fungus. After 5, 7, 10, 14, 15 and 21 days of incubation, approximately 100 eggs were removed from the plates and classified according to the following parameters: type 1, biochemical and physiological effect without morphological damage to the eggshell, type 2, lytic effect with morphological alteration of the eggshell and embryo and type 3, lytic effect with morphological alteration of eggshell and embryo showing hyphal penetration and internal egg colonization. The isolates effectively destroyed A. suum eggs and all types of effects were observed during the experiment. There was no variation in ovicidal capacity (type 3 effect) among the isolates (p>0.05) throughout the experiment. After 21 days, isolate 5 showed the highest percentages of type 3 effect (58.33%). The results indicated that P. chlamydosporia (Isol. 5, Isol. 31, Isol. 1, VC1, Isol. 12, Isol. 22 and VC4) can destroy A. suum eggs and is, therefore, a potential biological control agent of nematodes.

Biological control of Ascaris suum eggs by Pochonia chlamydosporia fungus

“…Still, for chlamydospores production is important to stand out this structure viability for its use in biological control environment (Larsen 1999;Terrill et al 2004) The present study showed A. suum eggs destruction (type 3 effect) by P. chlamydosporia isolates (VC4 and VC1) after a long period of interaction. These results are in agreement with Ferreira et al (2011) and Araújo et al (2008), that also reported the destruction of A. suum eggs after 21 days of interaction in vitro, with P. chlamydosporia (VC4 and VC1) grown in 2%WA medium. However, these studies have been conducted only in laboratory conditions, the fungus was already grown.…”

“…In this study the fungus P. chlamydosporia passed through the swines gastrointestinal tract, germinated from their feces and destroyed the A. suum eggs at the end of 30 days of interaction. Still in comparisons to the work of Ferreira et al (2011) and Araújo et al (2008), the obtained destruction percentages for VC4 and VC1 were the following: (57.67% and 55.3%) and (19% and 20%), respectively, at the end of study. The results in present study were similar (Table 1), at little different conditions.…”

“…Several works have reported the success of these fungi in biological control under laboratory conditions (grown fungus on solid medium, in vitro) and in natural conditions, passage through domestic animals gastrointestinal tract, with germination and growth in feces (Braga et al 2010a;Tavela et al 2010). Among the fungi species used, P. chlamydosporia has been successfully tested in vitro (Ferreira et al 2011) and after passing through the gastrointestinal tract of domestic animals (Braga et al 2010a;Singh et al 2010), however, there is no report about its passage through gastrointestinal tract of swines with subsequent germination and growth.…”

Formulation of Pochonia chlamydosporia for Plant and Nematode Management

“…chlamydosporia has also been applied to control animal parasitic nematodes (Ferreira et al 2011;Silva et al 2011) or other plantpathogenic fungi. Together with Pochonia rubescens and Lecanicillium lecanii, isolate 4624 was capable to reduce root colonisation and damage caused by the fungus Gaeumannomyces graminis var.…”

The capability of the fungus Mucor circinelloides to maintain parasiticidal activity after the industrial feed pelleting enhances the possibilities of biological control of livestock parasites

“…Pasture rotation is recommended for trying to reduce the risk of ascariosis among grazing animals. More recently, the usefulness of some soil fungi as Pochonia chlamydosporia against eggs of trematodes (Fasciola hepatica) and ascarids (Toxocara canis, Toxocara vitulorum, Ascaris suum) has been reported (Frassy et al, 2010;Carvalho et al, 2010;Ferreira et al, 2011).…”