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Lol, J. C.

Publications and source records attributed to Lol, J. C..

4 recordsLinked to original sources

Multi-omics analysis identifies loci associated with pyrethroid resistance across sister species in the Anopheles gambiae species complex

The Anopheles gambiae species complex includes An. gambiae, An. coluzzii, and An. arabiensis, three of the four major malaria vector species across Africa. Insecticide-based vector control remains the most critical tool in the fight against malaria, with a heavy reliance on pyrethroid insecticides. However, widespread pyrethroid resistance jeopardises the effectiveness of these methods. Currently, the number of diagnostic markers available to track pyrethroid resistance in endemic settings is limited, focusing mainly on changes at the insecticide target site. Genetic analysis of seven insecticide-resistant populations from West Africa, a region with intense insecticide resistance, reveals shared loci associated with pyrethroid resistance among the sister species of the An. gambiae complex including kdr, GSTE1-8 and the CYP6P region. Notably, a mutation in the voltage-gated sodium channel, I1527T, previously identified in An. coluzzii and An. gambiae, was detected in wild-caught An. arabiensis from Burkina Faso. Additionally, a mutation, L207I, in GSTE7 common to An. coluzzii and An. arabiensis, significantly increases survivorship to deltamethrin. With the additional integration of RNAseq and data from the Anopheles gambiae 1000 genomes project, we were able to identify putative eQTLs associated with the expression of major insecticide resistance-related transcripts, such as CYP6P3, CYP9K1 and CYP6AA1. This study reveals several potential diagnostic markers of resistance that can be implemented in endemic settings and identifies putative introgression between An. arabiensis and An. coluzzii in Burkina Faso.

genetics↗

Geographic heterogeneity in Anopheles albimanus microbiota is lost within one generation of laboratory colonization

BackgroundResearch on mosquito-microbe interactions may lead to new tools for mosquito and mosquito-borne disease control. To date, such research has largely utilized laboratory-reared mosquitoes that typically lack the microbial diversity of wild populations. A logical progression in this area involves working under controlled settings using field-collected mosquitoes or, in most cases, their progeny. Thus, an understanding of how laboratory colonization affects the assemblage of mosquito microbiota would aid in advancing mosquito microbiome studies and their applications beyond laboratory settings. MethodsUsing high throughput 16S rRNA amplicon sequencing, we characterized the internal and cuticle surface microbiota of F1 progeny of wild-caught adult Anopheles albimanus from four locations in Guatemala. A total of 132 late instar larvae and 135 2-5day old, non-blood-fed virgin adult females that were reared under identical laboratory conditions, were pooled (3 individuals/pool) and analyzed. ResultsResults showed geographical heterogeneity in both F1 larval internal (p=0.001; pseudo-F = 9.53) and cuticle surface (p=0.001; pseudo-F = 8.51) microbiota, and only F1 adult cuticle surface (p=0.001; pseudo-F = 4.5) microbiota, with a more homogenous adult internal microbiota (p=0.12; pseudo-F = 1.6) across collection sites. Overall, ASVs assigned to Leucobacter, Thorsellia, Chryseobacterium and uncharacterized Enterobacteriaceae, dominated F1 larval internal microbiota, while Acidovorax, Paucibacter, and uncharacterized Comamonadaceae, dominated the larval cuticle surface. F1 adults comprised a less diverse microbiota compared to larvae, with ASVs assigned to the genus Asaia dominating both internal and cuticle surface microbiota, and constituting at least 70% of taxa in each microbial niche. ConclusionsThese results suggest that location-specific heterogeneity in filed mosquito microbiota can be transferred to F1 progeny under normal laboratory conditions, but this may not last beyond the F1 larval stage without adjustments to maintain field-derived microbiota. Our findings provide the first comprehensive characterization of laboratory-colonized F1 An. albimanus progeny from field-derived mothers. This provides a background for studying how parentage and environmental conditions differentially or concomitantly affect mosquito microbiome composition, and how this can be exploited in advancing mosquito microbiome studies and their applications beyond laboratory settings.

microbiology↗

Co-occurrence of kdr mutations V1016I and F1534C in pyrethroid-resistant Aedes aegypti (Diptera: Culicidae) populations from Costa Rica

Aedes aegypti (Linnaeus, 1762) is considered the most important mosquito vector species for several arboviruses (e.g., dengue, chikungunya, Zika) in Costa Rica. The main strategy for the control and prevention of Aedes-borne diseases relies on insecticide-based vector control. However, the emergence of insecticide resistance in the mosquito populations present a big threat for the prevention actions. The characterization of the mechanisms driving the insecticide resistance in Ae. aegypti are vital for decision making in vector control programs. Therefore, we analyzed the voltage-gated sodium channel gene for the presence of the V1016I and F1534C kdr mutations in pyrethroid-resistant Ae. aegypti populations from Puntarenas and Limon provinces, Costa Rica. The CDC bottle bioassays showed that both Costa Rican Ae. aegypti populations were resistant to permethrin and deltamethrin. In the case of kdr genotyping, results revealed the co-occurrence of V1016I and F1534C mutations in permethrin and deltamethrin-resistant populations, as well as the fixation of the 1534C allele. Therefore, our findings make an urgent call to expand the knowledge about the insecticide resistance status and mechanisms in the Costa Rican populations of Ae. aegypti which must be a priority to develop an effective resistance management plan.

genetics↗

Pyrethroid exposure alters Anopheles albimanus microbiota and resistant mosquitoes harbor more insecticide-metabolizing bacteria

A deeper understanding of the mechanisms underlying insecticide resistance is needed to mitigate its threat to malaria vector control. Building upon our earlier identified associations between mosquito microbiota and insecticide resistance, we demonstrate for the first time, type-specific effects of pyrethroid exposure on internal and cuticle surface bacteria in adult progeny of field-collected Anopheles albimanus. In contrast, larval cuticle surface--but not internal--bacteria were affected by pyrethroid exposure. Being over five-folds more abundant in pyrethroid resistant adults, as compared to susceptible or non-insecticide-exposed mosquitoes, Klebsiella (alphacypermethrin), Pantoea and Asaia (permethrin) were identified as potential markers of pyrethroid resistance in An. albimanus. We also show for the first time that An. albimanus larvae and adult cuticles harbor more diverse bacterial communities than their internal microbial niches. Our findings indicate insecticide selection pressures on mosquito microbiota, and support the hypothesis of an undescribed microbe-mediated mechanism of insecticide metabolism in mosquitoes.

microbiology↗