A Novel Model of Pathogenesis of <i>Metarhizium anisopliae</i> Propagules through the Midguts of <i>Aedes aegypti</i> Larvae
Ricardo de Oliveira Barbosa Bitencourt,
Jacenir Reis dos Santos-Mallet,
Carl Lowenberger,
Adriana Ventura,
Patrícia Silva Gôlo,
Vânia Rita Elias Pinheiro Bittencourt,
Isabele da Costa Angelo
Affiliations
Ricardo de Oliveira Barbosa Bitencourt
Graduate Program in Veterinary Sciences, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica 23890-000, RJ, Brazil
Jacenir Reis dos Santos-Mallet
Oswaldo Cruz Foundation, IOC-FIOCRUZ-RJ, Rio de Janeiro 21040-900, RJ, Brazil
Carl Lowenberger
Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
Adriana Ventura
Department of Animal Biology, Institute of Health and Biological Sciences, Federal Rural University of Rio de Janeiro, Seropédica 23890-000, RJ, Brazil
Patrícia Silva Gôlo
Department of Animal Parasitology, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica 23890-000, RJ, Brazil
Vânia Rita Elias Pinheiro Bittencourt
Department of Animal Parasitology, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica 23890-000, RJ, Brazil
Isabele da Costa Angelo
Department of Epidemiology and Public Health, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica 23890-000, RJ, Brazil
We assessed the effect of the entomopathogenic fungus Metarhizium anisopliae against Aedes aegypti. Conidia of M. anisopliae strains CG 489, CG 153, and IBCB 481 were grown in Adamek medium under different conditions to improve blastospore production. Mosquito larvae were exposed to blastospores or conidia of the three fungal strains at 1 × 107 propagules mL−1. M. anisopliae IBCB 481 and CG 153 reduced larval survival by 100%, whereas CG 489 decreased survival by about 50%. Blastospores of M. anisopliae IBCB 481 had better results in lowering larval survival. M. anisopliae CG 489 and CG 153 reduced larval survival similarly. For histopathology (HP) and scanning electron microscopy (SEM), larvae were exposed to M. anisopliae CG 153 for 24 h or 48 h. SEM confirmed the presence of fungi in the digestive tract, while HP confirmed that propagules reached the hemocoel via the midgut, damaged the peritrophic matrix, caused rupture and atrophy of the intestinal mucosa, caused cytoplasmic disorganization of the enterocytes, and degraded the brush border. Furthermore, we report for the first time the potential of M. anisopliae IBCB 481 to kill Ae. aegypti larvae and methods to improve the production of blastospores.
