title: 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.
authors.affiliation: Department of Veterinary Medicine, Universidade Estadual do Centro Oeste, UNICENTRO, Rua Simeão Camargo Varela de Sá, 03. CEDETEG, Guarapuava, PR, CEP 85040-080, Brazil. margaretefalbo@hotmail.com
authors.forename: Margarete Kimie
authors.initials: MK
authors.lastname: Falbo
authors.forename: Vanete Thomaz
authors.initials: VT
authors.lastname: Soccol
authors.forename: Itacir Eloi
authors.initials: IE
authors.lastname: Sandini
authors.forename: Vânia Aparecida
authors.initials: VA
authors.lastname: Vicente
authors.forename: Diogo
authors.initials: D
authors.lastname: Robl
authors.forename: Carlos Ricardo
authors.initials: CR
authors.lastname: Soccol
mesh_terms: D000818:Animals; D001203:Ascomycota / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity* / Q000648:ultrastructure; D001938:Brazil; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D007814:Larva / Q000382:microbiology; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D014251:Trichostrongyloidea / Q000382:microbiology*
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer