Pathogenicity of the entomopathogenic fungus Beauveria bassiana 9205 in rats using different routes of exposition

Abstract

Among fungi intended for biological control, great efforts have been made in the development of entomopathogenic Hyphomycetes, like Beauveria bassiana, which have a wide host range. The aim of this study was to assess and to compare the pathogenicity of B. bassiana strain 9205 in rats through oral, intranasal, and intravenous dosing. Through 21 days after administration, clinical examinations were performed daily, and body weight gain was evaluated. Clearance was estimated by means of collection of feces or examination of lungs and blood, and infectivity was evaluated enumerating microorganisms from organs of animals sacrificed at intervals. Gross necropsy of animals was performed at interim or final sacrifice. There were no mortalities, and no evidence of pathogenicity or treatment-related toxicity, although the microorganism was capable of achieving significative infectivity in organs after intravenous administration. The obtained results suggest the innocuity of B. bassiana in rats and the necessity of more prolonged studies through intravenous injection.

Keywords:

• biological control
• Beauveria bassiana
• pathogenicity
• clearance
• infectivity