Resumen de Current enzyme-mediated insecticide resistance status of Aedes aegypti populations from a dengue-endemic city in southern Mexico

Francisco Solís Santoyo, Américo David Rodríguez, William Black, Karla Saavedra Rodríguez, Daniel Sánchez Guillén, Alfredo Castillo Vera, Rebeca González-Gómez, Alma Delia López Solís, Rosa Patricia Penilla

• español

  Objetivo. Identificar la resistencia a insecticidas mediada por enzimas en Aedes aegypti de Tapachula, México. Material y métodos. Se realizaron ensayos bioquímicos para calcular los niveles enzimáticos en mosquitos de 22 sitios colectados en Tapachula en 2018 y 2020. Resultados de 2018se correlacionaron con la resistencia a insecticidas publicada. Resultados. Se obtuvieron niveles más altos que los de la cepa susceptible en 2018 y 2020, respectivamente, de: α-esterasas en 15 y 12 sitios; β-esterasas en 7 y 6 sitios; glutatión-S-transferasas en 11 y 19 sitios; ρNPA-esterases en 21 y 17 sitios; y citocromos P450 en 20 y 22 sitios. Los índices publicados de resistencia al malatión y la acetilcolinesterasa insensible tuvieron una correlación moderada (r=0.459, p= 0.03) en mosquitos de 2018. Conclusiones. Los altos niveles enzimáticos encontrados indican su contribución en a resistencia a piretroides y organofosforados en mosquitos de Tapachulade 2018. Bioensayos con inhibidores enzimáticos dieron mayores mortalidades, confirmando que el metabolismo contribuye en la resistencia.

• English

  Objective. To identify the enzyme-mediated insecticide resistance in Aedesaegypti in Tapachula, Mexico. Materials and methods. Biochemical assays wereundertaken to determine the enzyme levels in mosquitoes from 22 sites collected in 2018 and 2020 in Tapachula. Results of 2018 were correlated with the resistance to insecticides pub-lished. Results. Mosquitoes had higher levels than those of the susceptible strain in 2018 and 2020 respectively of α-esterases in 15 and 12 sites; β-esterases in 7 and 6 sites; glutathione-S-transferases in 11 and 19 sites; ρNPA-esterases in 21 and 17 sites; and cytochromes P450 in 20 and 22 sites. In mosquitoes of 2018, there was a moderate correlation between previously documented Malathion resistance ratios and the insensitive acetylcholinesterase (r=0.459, p= 0.03). Conclusions. The elevated enzyme levels found indicate its contribution to the resistance to pyrethroids and organo-phosphates already published in mosquitoes from Tapachula. Bioassays using enzyme inhibitors resulted in greater mor-tality, confirming that metabolism contributes to resistance.