Analysis of the effect of soil saprophytic fungi on the eggs of Baylisascaris procyonis

Abstract

Baylisascaris procyonis is a soil-transmitted helminth mainly found in raccoons (Procyon lotor) which can also affect other domestic and sylvatic animals, as well as humans, when the eggs released in the feces of parasitized raccoons are accidentally ingested. Three assays have been conducted to assess the effect of three saprophytic fungi, Mucor circinelloides, Paecilomyces lilacinus, and Verticillium sp., on the eggs of B. procyonis. Firstly, their ovicidal effect was in vitro ascertained by placing 1 mL with 2 × 10(6) spores of each fungus in Petri plates with water-agar (2 %) and simultaneously adding 200 eggs of Baylisascaris/plate. Two in vivo probes were carried out, by spraying the fungal spores (3 mL containing about 2 × 10(6) spores/mL) on the feces of raccoons and coatis (Nasua narica) passing eggs of B. procyonis in a zoological park; the other assay consisted of evaluating the activity of the fungi after adding sand to fecal samples from raccoons. An ovicidal type 3 activity characterized by morphological damage of the eggshell with hyphal penetration, internal egg colonization, and embryo alteration was observed for all the tested fungi. In the plate assays, viability of Baylisascaris eggs reduced significantly by 53-69 % with Mucor, 45-62 % with Paecilomyces, and 52-67 % with Verticillium. A similar ovicidal effect was detected in the feces with sand. These results demonstrate the usefulness of spraying spores of M. circinelloides, Pa. lilacinus, or Verticillium sp. on the feces of animals infected by Baylisascaris to decrease the numbers of viable eggs and, thus, the risk of infection.

Advantageous Fungi against Parasites Transmitted through Soil

“…As drawn in Figures 3 and 4, the addition of spores of M. circinelloides to the feces of dogs infected by T. c a n i s decreased their viability by half after a period of 30 days [29]. When the spores were sprayed onto feces of raccoons parasitized by B. procyonis, egg viability reduced by two-thirds also, in agreement with previous experiments [30].…”

Isolation of Ovicidal Fungi from Fecal Samples of Captive Animals Maintained in a Zoological Park

“…By applying the flotation probe, eggs of roundworms ( Parascaris equorum ) were identified in the feces of horses, then purified [ 21 ], and finally kept at a concentration of 800 eggs/mL.…”

“…Most known species with ovicidal activity are Verticillium spp., Pochonia chlamydosporia , Paecilomyces lilacinus , Trichoderma spp., or Mucor circinelloides [ 18 , 19 , 20 ]. By developing the phases of adhesion, colonization, penetration, and deliberation, these fungi develop an ovicidal activity [ 21 , 22 ]. Recently, the role of Trichoderma spp.…”

Control biológico de zoonosis en parques zoológicos: trichurosis y capillariosis

“…Al microscopio se determinó la viabilidad de los huevos de los nematodos, y se consideraron no viables si presentaban alteraciones en la cubierta, estructuras internas poco marcadas o destrucción del embrión interior (Cazapal-Monteiro et al, 2015).…”