INIBIOLP   05426
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE LA PLATA "PROF. DR. RODOLFO R. BRENNER"
Unidad Ejecutora - UE
artículos
Título:
Control of pyrethroid-resistant Chagas disease vectors with entomopathogenic fungi.
Autor/es:
N. PEDRINI; S. MIJAILOVSKY; J.R. GIROTTI; R. STARIOLO; R.M. CARDOZO; A. GENTILE; M.P. JUÁREZ
Revista:
PLOS NEGLECTED TROPICAL DISEASES
Editorial:
Public Library of Science
Referencias:
Año: 2009 vol. 3 p. 1 - 10
ISSN:
1935-2727
Resumen:
Background: Triatoma infestans-mediated transmission of Tripanosoma cruzi, the causative agent of Chagas disease, remains as a major health issue in southern South America. Key factors of T. infestans prevalence in specific areas of the geographic Gran Chaco region—which extends through northern Argentina, Bolivia, and Paraguay—are both recurrent reinfestations after insecticide spraying and emerging pyrethroid-resistance over the past ten years. Among alternative control tools, the pathogenicity of entomopathogenic fungi against triatomines is already known; furthermore, these fungi have the ability to fully degrade hydrocarbons from T. infestans cuticle and to utilize them as fuel and for incorporation into cellular components. Methodology and Findings: Here we provide evidence of resistance-related cuticle differences; capillary gas chromatography coupled to mass spectrometry analyses revealed that pyrethroid-resistant bugs have significantly larger amounts of surface hydrocarbons, peaking 56.266.4% higher than susceptible specimens. Also, a thicker cuticle was detected by scanning electron microscopy (32.165.9 mm and 17.865.4 mm for pyrethroid-resistant and pyrethroidsusceptible, respectively). In laboratory bioassays, we showed that the virulence of the entomopathogenic fungi Beauveria bassiana against T. infestans was significantly enhanced after fungal adaptation to grow on a medium containing insect-like hydrocarbons as the carbon source, regardless of bug susceptibility to pyrethroids. We designed an attraction-infection trap based on manipulating T. infestans behavior in order to facilitate close contact with B. bassiana. Field assays performed in rural village houses infested with pyrethroid-resistant insects showed 52.4% bug mortality. Using available mathematical models, we predicted that further fungal applications could eventually halt infection transmission. Conclusions: This low cost, low tech, ecologically friendly methodology could help in controlling the spread of pyrethroidresistant bugs.