Isolation of from the Chagas Disease Vector in the Gran Chaco Region of Argentina: Assessment of Gene Expression during Host-Pathogen Interaction.

A native strain of the entomopathogenic fungus (Bb-C001) was isolated from a naturally infected , Klug (Hemiptera: Reduviidae) adult cadaver in the Gran Chaco region, Salta province, Argentina. The isolate was both phenotypic and molecularly characterized in a context of fungus-insect interaction, by measuring the expression pattern of toxin genes during infection and immune response of . The commercial strain GHA of , which was previously used in field interventions to control these vectors, was used as reference in this study. The phylogenetic trees based on both ribosomal internal transcribed spacer (ITS) and elongation factor 1-alpha (EF1-α) indicated that Bb-C001 fits into a cluster, and the sequence-characterized amplified regions (SCAR) showed that Bb-C001 is different from the GHA strain. There were no differences between both strains regarding viability, radial growth, and conidia production, either in the median survival time or insect mortality. However, Bb-C001 showed a higher expression than GHA of the bassianolide synthetase gene () during infection, and similar levels of the beauvericin synthetase gene (). Immune-related genes of nymphs ( and and ) were later expressed and thus insects failed to stop the infection process. These results showed that Bb-C001 is a promised fungal strain to be incorporated in the current biological control programs of in Salta province, Argentina.