Ovicidal action of a crude enzymatic extract of the fungus Pochonia chlamydosporia against cyathostomin eggs

Abstract

The aims of this study were to test the action of the fungal extract of Pochonia chlamydosporia (VC4) on the hatching of cyathostomin eggs plated in Petri dishes containing 2% water-agar (2% WA) and its enzymatic activity in fecal cultures, in two experimental assays (A and B). The fungus P. chlamydosporia (VC4) was cultured in Erlenmeyer flasks (250ml) containing 50ml of liquid minimal medium supplemented with 0.2% gelatin for production of the crude enzymatic extract. Approximately 1kg of fresh feces was collected directly from the rectum of crossbred horses naturally infected with cyathostomins. The fecal material was used to obtain eggs and prepare fecal cultures. For assay A, one thousand eggs were plated on 4.5cm diameter Petri dishes together with 5ml of VC4 fungal filtrate and incubated at 26 degrees C in the dark for 24h. The control group consisted of 1000 eggs in Petri dishes containing 10ml of distilled water, which were incubated under the same conditions. After 24h, the total number of cyathostomin larvae present in each plate of the treated and control groups was counted. For assay B, about 20g of feces were added with 10ml of fungal extract of P. chlamydosporia (VC4) and incubated at 26 degrees C for 8 days. Third stage larvae (L(3)) were recovered at the end of this period. Significant difference (p<0.01) was found for the number of larvae between the treated group and the control at end of assay A. A 72.8% reduction in the hatching of cyathostomin eggs was found in the plates of the treated group compared with the control group. At the end of 8 days, the fungal extract of P. chlamydosporia (VC4), in assay B, was effective in reducing the number of L(3) cyathostomins in the treated group by 67.0% compared with the control group. Significant difference (p<0.01) was found between the means of L(3) recovered from the treated group and the control group. The results of this work showed that crude enzymatic extract of P. chlamydosporia (VC4) was effective in reducing hatching of cyathostomin eggs and therefore could be used as a biological control agent of this nematode.

Activity of Euterpe edulis Martius, Mikania glomerata Spreng, and Mikania laevigata Schultz Bip. Extracts on Gastrointestinal Nematodes Toxocara canis and Ancylostoma caninum

“…Most research is directed towards the evaluation of T. canis larvae (13,19) or towards the activity of nematophagous fungi, among which Pochonia chlamydosporia, which mostly produce proteases capable of destroying the eggs of gastrointestinal nematodes (16).…”

“…After each study period, the total number of embryonated and/or non-embryonated eggs, present in each tube of the treated and control groups, was calculated according to the methodology described by Braga et al (16).…”

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

“…Due to its zoonotic potential, among the gastrointestinal helminths, Ancylostoma spp has attracted great attention. Ancylostoma caninum and A. braziliense are intestinal geohelminths from dogs and cats and have required great attention because of their zoonotic potential by means of direct soil contamination with the faeces of infected animals, since their infective larvae (L3) are present in this contaminated environment [1,2]. Nowadays alternative measures to control these and other domestic animal endoparasitosis are searched in order to decrease use of chemotherapeutics and, consequently, the reduction of pollutant levels in the environment and in animal originating products [3].…”

Nematicidal activity of Paecilomyces marquandii proteases on infective larvae of Ancylostoma spp

“…Biological control has emerged as one of the possible biotechnological applications of fungal enzymes. Some researchers suggest that these enzymes are directly involved in the hydrolytic action on nematodes (3,5,9,12,15). In this regard, proteases are the main enzymes produced by the nematophagous fungi in order to break the cuticle of nematodes.…”

“…After the 24 hour period the total number of viable larvae Ancylostoma spp. present in each tube of the treated and control groups was counted (3). The data obtained in this assay were interpreted by analysis of variance in levels of significance of 5% probability (1).…”