Insecticide resistance status and mechanisms in Aedes aegypti and Aedes albopictus from different dengue endemic regions of Panama

Authors: CACERES CARRERA, LORENZO - Gorgas Memorial Institute Of Health Studies; PIEDRA, LUIS - Instituto De Medicina Tropical Pedro Kouri; TORRES-COSME, ROLANDO - Gorgas Memorial Institute Of Health Studies; CASTILLO, ANAKENA - Gorgas Memorial Institute Of Health Studies; BRUNO, ANTONIO - Gorgas Memorial Institute Of Health Studies; Ramirez, Jose; MARTINEZ, DAN - Gorgas Memorial Institute Of Health Studies; MAGDALENA RODRIGUEZ, MARIA - Instituto De Medicina Tropical Pedro Kouri; BISSET, JUAN - Instituto De Medicina Tropical Pedro Kouri

Submitted to: Tropical Medicine and Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2024
Publication Date: 10/9/2024
Citation: Caceres Carrera, L., Piedra, L., Torres-Cosme, R., Castillo, A.M., Bruno, A., Ramirez, J.L., Martinez, D., Magdalena Rodriguez, M., Bisset, J.A. 2024. Insecticide resistance status and mechanisms in Aedes aegypti and Aedes albopictus from different dengue endemic regions of Panama. Tropical Medicine and Health.
DOI: https://doi.org/10.1186/s41182-024-00637-w

Interpretive Summary: Aedes aegypti (yellow fever mosquito) and Aedes albopictus (Asian tiger mosquito) are important vectors of several human viral pathogens including dengue, Zika, chikungunya and yellow fever viruses. Their control relies primarily on the use of insecticides. However, these mosquito species have developed resistance to all insecticide classes approved for vector control, significantly affecting disease control efforts throughout the world. This study evaluated insecticide resistance status of Ae. aegypti and Ae. albopictus populations collected from different regions of Panama and determined the underlying mechanisms of resistance. The two mosquito species showed variable and widespread resistance to the commonly used insecticides, which may be due to variations in the type of insecticides used by vector control agencies or households. These findings provide a much-needed guide for mosquito control agencies, aiding in the selection of effective alternative insecticides for the control of insecticide-resistant Aedes populations.

Technical Abstract: Chemical control remains the main strategy for limiting mosquito population density and interrupting the transmission of arboviruses transmitted by Aedes mosquitoes. However, the excessive and intense use of insecticides generates high selective pressure, leading to the rapid development of resistance in wild populations. The objective of this study was to evaluate the status of insecticide resistance, its mechanisms, and the detection of allelic variants of the knockdown resistance (kdr) gene in wild populations of Ae. aegypti and Ae. albopictus. Susceptibility bioassays were performed with adult mosquitoes and larvae with representatives of pyrethroid (PY), organochlorine (OC), organophosphate (OP) and carbamate (CA) insecticide classes according to the World Health Organization (WHO) protocol. Biochemical tests were used to evaluate the enzymatic profiles of a-naphthyl esterase (a-EST), ß-naphthyl acetate esterase (ß-EST), mixed function oxidases (MFO), glutathione S-transferases (GSTs) and acetylcholinesterase (AchE). The kdr gene variants were determined by RT-PCR and the Ae. aegypti Rockefeller strain was used as the susceptible control. In adult susceptibility bioassays, varied and generalized resistance to PY and OP was detected in 13 strains of Ae. aegypti and 13 strains of Ae. albopictus. In larval bioassays, all strains of Ae. aegypti and Ae. albopictus were susceptible to the insecticides tested. This study indicates resistance to multiple insecticides present in Ae. aegypti and Ae. albopictus populations from different regions in Panama. The results from this study provide an important resource to mosquito control agencies, aiding in the selection of effective alternative insecticides for the control of insecticide-resistant mosquitoes.