Scanning electron microscopy of Ancylostoma spp. dog infective larvae captured and destroyed by the nematophagous fungus Duddingtonia flagrans

Abstract

The interaction between the nematode-trapping fungus Duddingtonia flagrans (isolate CG768) against Ancylostoma spp. dog infective larvae (L(3)) was evaluated by means of scanning electron microscopy. Adhesive network trap formation was observed 6h after the beginning of the interaction, and the capture of Ancylostoma spp. L(3) was observed 8h after the inoculation these larvae on the cellulose membranes colonized by the fungus. Scanning electron micrographs were taken at 0, 12, 24, 36 and 48 h, where 0 is the time when Ancylostoma spp. L(3) was first captured by the fungus. Details of the capture structure formed by the fungus were described. Nematophagous Fungus Helper Bacteria (NHB) were found at interactions points between the D. flagrans and Ancylostoma spp. L(3). The cuticle penetration by the differentiated fungal hyphae with the exit of nematode internal contents was observed 36 h after the capture. Ancylostoma spp. L(3) were completely destroyed after 48 h of interaction with the fungus. The scanning electron microscopy technique was efficient on the study of this interaction, showing that the nematode-trapping fungus D. flagrans (isolate CG768) is a potential exterminator of Ancylostoma spp. L(3).

In vitro biological control of infective larvae of Ancylostoma ceylanicum

“…These results are consistent with the observations made by Maciel et al (2009) andCarvalho et al (2009), who examined the effect of D. flagrans on the L 3 of gastrointestinal nematodes of potentially zoonotic domestic animals.…”

A parasitological paradox: Why is ascarid infection so rare in the prehistoric Americas?

“…Currently, 150 species are known, divided in three groups: nematode predators, endoparasites, and egg opportunistic parasites (Gray, 1987). Many genera, such as Arthrobotrys, Duddingtonia, Pochonia and Monascroporium are efficient in controlling animal intestinal parasitosis (Wang et al, 2008;Araújo et al, 2009aAraújo et al, , 2009bBraga et al, 2009aBraga et al, , 2009bCarvalho et al, 2009;Kelly et al, 2009;Maciel et al, 2009aMaciel et al, , 2009b. These fungal taxa are distributed throughout the world and in every kind of climate (Gray, 1987).…”

Isolation, identification, and characterization of the nematophagous fungus Monacrosporium salinum from China

“…The differentiated fungal hyphae penetrate the nematode cuticle after capturing it; the hyphae then grow within the nematode, digest its inner contents, and project its vegetative hyphae to the surface . These events were observed in our SEM micrographs (Fig.…”

“…This phenomenon can also explain the long time required for the penetration of L 3 . Furthermore, the infective hyphae causes depression in the sheath during the interaction period, providing evidence of mechanical pressure . Nevertheless, penetration probably involves mechanical pressure and the activity of hydrolytic enzymes that solubilize the macromolecules of the cuticle .…”

“…, and Maciel et al . , the materials were prepared for scanning electron microscopy (SEM). Dialysis membrane discs (6 cm in diameter) were cut and placed in 250 ml beakers, which were then filled with distilled water up to the 150 ml mark and autoclaved at 121 °C for 15 min.…”