title: Lack of pathogenicity and toxicity of the mycoinsecticide Metarhizium anisopliae var. acridum following acute gastric exposure in mice.
abstract: Metarhizium anisopliae var. acridum, monospore culture EH-502/8 (CNRCB MaPL40), isolated in Mexico from Schistocerca piceifrons ssp. piceifrons (Orthoptera: Acrididae) was tested for acute oral intragastric pathogenicity and toxicity in CD-1 mice. Animals were inoculated with one dose (10(8) conidia/animal) of viable (72 mice), non-viable (24 mice) conidia and compared to 18 control mice. Clinical observations were done daily; mycological and histological tests were performed during necropsies after the inoculation. No mice showed clinical symptoms of illness or died during the study. The fungus was able to persist in some organs until day 3, but did not cause any damage to the host. The gross pathology observed was splenomegaly in mice inoculated with viable and non-viable conidia. Non-germinated conidia, observed in several organs, suggest hematogenous spread, but without any histopathological tissue reaction. Results support the non-pathogenic and non-toxic status of this fungal strain when administered in a single intragastric dose to mice.
authors.affiliation: Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, México D.F. 04510, México. toriello@servidor.unam.mx
authors.forename: Conchita
authors.initials: C
authors.lastname: Toriello
authors.forename: Armando
authors.initials: A
authors.lastname: Pérez-Torres
authors.forename: Fabiola
authors.initials: F
authors.lastname: Vega-García
authors.forename: Hortensia
authors.initials: H
authors.lastname: Navarro-Barranco
authors.forename: Amelia
authors.initials: A
authors.lastname: Pérez-Mejía
authors.forename: Marte
authors.initials: M
authors.lastname: Lorenzana-Jiménez
authors.forename: Victor
authors.initials: V
authors.lastname: Hernández-Velázquez
authors.forename: Teresa
authors.initials: T
authors.lastname: Mier
mesh_terms: D000284:Administration, Oral; D000818:Animals; D006110:Grasshoppers / Q000382:microbiology; D008099:Liver / Q000382:microbiology / Q000473:pathology; D052981:Metarhizium / Q000166:cytology / Q000472:pathogenicity*; D051379:Mice; D009181:Mycoses / Q000473:pathology; D010572:Pest Control, Biological; D013163:Splenomegaly / Q000382:microbiology / Q000473:pathology; D013172:Spores, Fungal / Q000472:pathogenicity; D013270:Stomach / Q000382:microbiology; D023382:Toxicity Tests, Acute