Interplay Between Plasmodium Infection and Resistance to Insecticides in Vector Mosquitoes

Abstract

Despite its epidemiological importance, the impact of insecticide resistance on vector-parasite interactions and malaria transmission is poorly understood. Here, we explored the impact of Plasmodium infection on the level of insecticide resistance to dichlorodiphenyltrichloroethane (DDT) in field-caught Anopheles gambiae sensu stricto homozygous for the kdr mutation. Results showed that kdr homozygous mosquitoes that fed on infectious blood were more susceptible to DDT than mosquitoes that fed on noninfectious blood during both ookinete development (day 1 after the blood meal) and oocyst maturation (day 7 after the blood meal) but not during sporozoite invasion of the salivary glands. Plasmodium falciparum infection seemed to impose a fitness cost on mosquitoes by reducing the ability of kdr homozygous A. gambiae sensu stricto to survive exposure to DDT. These results suggest an interaction between Plasmodium infection and the insecticide susceptibility of mosquitoes carrying insecticide-resistant alleles. We discuss this finding in relation to vector control efficacy.

Adaptive deletion in resistance gene duplications in the malaria vector Anopheles gambiae

“…gambiae with a large adaptive capacity to various treatment regimens. Unfortunately, resistance (and particularly ace‐1 R alleles) has been shown to impact the malaria pathogen transmission (Alout et al., 2013; Alout, Djègbè et al., 2014; Alout, Yameogo et al., 2014; Alout et al., 2016), although its net impact on malaria transmission is still debated (Alout, Labbé, Chandre, & Cohuet, 2017). The original finding, in R x alleles, of a cost proportionally increasing with the R copy number, suggested a reassuring cap to the levels of resistance reachable by An.…”

Larval nutritional stress affects vector life history traits and human malaria transmission

“…In particular a high frequency of the L1014 kdr mutation is observed in An . coluzzii females (60 to 90%)48 which could also affect their competence4950.…”

Putting evolution in elimination: Winning our ongoing battle with evolving malaria mosquitoes and parasites

“…The deployment of resistance mechanisms by the mosquito could potentially be toxic to the parasite (Kristan et al., ). On the other hand, kdr mutations have been correlated with increased sporozoite prevalence, both in laboratory setting (Alout et al., , ) and in the field (Kabula et al., ; Ndiath et al., ). As such, the overall effect of insecticide resistance on parasite transmission is still unclear, yet these studies highlight that vector control and parasite epidemiology cannot be seen independently.…”