Isolation and characterization of the nematophagous fungus Arthrobotrys conoides

Abstract

The spread of organic farming and the development of resistance to anthelmintics by parasites, especially in small ruminants, have necessitated the search for alternative methods of nematode control. Biological control using nematophagous fungi is one option; however, few studies have been conducted with native strains. The present study was divided into two phases. In the first phase, we aimed to isolate, identify, and assess the in vitro predatory activity of nematophagous fungi that had been isolated on Trichostrongylidae third-instar larvae. In the second phase, the isolate with superior predatory activity in vitro was molecularly characterized, and its morphological plasticity was observed using scanning electron microscopy (SEM) on Haemonchus third-instar larvae. Of the 56 soil samples from different regions of Paraná State, Brazil, 57 fungal strains were recovered, of which four exhibited predatory activity. Two pure isolates were obtained: the CED and LIN strains. After demonstrating 96.35 % predatory activity for the CED strain, this strain was selected and characterized using molecular criteria by sequencing the rDNA internal transcribed spacer and was identified as Arthrobotrys conoides (GenBank ID: JN191309). Morphological patterns in this strain during the interaction between the fungus and the nematode were revealed by SEM, in which two extensions of the infection bulb that was used to pierce the nematode's cuticle were clearly visible.

Effect of spraying Arthrobotrys conoides conidia on pastures to control nematode infection in sheep

“…Falbo et al (2013) verified that the A. conoides strain (JN 191309) does not lose its predatory capacity even after the passage by the gastrointestinal tract of lambs.…”

“…In vitro testing with the A. conoides strain showed 96.35% efficiency after passage through the sheep gastrointestinal tract in decreasing the population of several nematode species in a pool containing 64% Haemonchus sp., 22% Trichostrongylus sp. and 14% Strongyloides papillosus (FALBO et al, 2013).…”

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

“…The purified PCR products (DNA Gel Extraction Kit, Solarbio, China) were sequenced; sequence analysis was performed by the BLAST sequence alignment software of the NCBI database (National Center for Biotechnology Information [http://www.ncbi.nlm.nih.gov/]). Phylogenetic analyses were performed by MEGA version 5.10 with the neighbor‐joining (NJ) statistical method and the Jukes‐Cantor model . The nucleotide sequences obtained in this study were submitted to GenBank (accession number KP036623).…”

Cogumelos uma fonte promissora de compostos ativos para o desenvolvimento de produtos farmacêuticos e nutracêuticos

“…Estudos envolvendo fungos nematófagos na saúde animal tiveram seu início no século XX, na França 132,133 . Na década de 1990, vários estudos com fungos nematófagos foram realizados, impulsionados pela busca de alternativas no controle da verminose, tendo em vista o crescente aumento da resistência anti-helmíntica, principalmente em pequenos ruminantes, relatado por diversos pesquisadores do Brasil [134][135][136][137][138] e de outras regiões do mundo [139][140][141] .…”