Western Kenyan Anopheles gambiae showing intense permethrin resistance harbour distinct microbiota

Study information

Needs review

study design

laboratory experiment

Citation

PMID PubMed identifier for scientific articles.

33557825

DOI Digital object identifier for electronic documents.

10.1186/s12936-021-03606-4

URI

Authors

Omoke D, Kipsum M, Otieno S, Esalimba E, Sheth M, Lenhart A, Njeru EM, Ochomo E, Dada N

Journal

Malaria journal

Year

2021

Keywords:

16S rRNA gene amplicon sequencing, Anopheles gambiae s.s., Insecticide resistance, Metabarcoding, Mosquito microbiome, Mosquito microbiota, pyrethroid resistance

BACKGROUND: Insecticide resistance poses a growing challenge to malaria vector control in Kenya and around the world. Following evidence of associations between the mosquito microbiota and insecticide resistance, the microbiota of Anopheles gambiae sensu stricto (s.s.) from Tulukuyi village, Bungoma, Kenya, with differing permethrin resistance profiles were comparatively characterized. METHODS: Using the CDC bottle bioassay, 133 2-3 day-old, virgin, non-blood fed female F1 progeny of field-caught An. gambiae s.s. were exposed to five times (107.5 µg/ml) the discriminating dose of permethrin. Post bioassay, 50 resistant and 50 susceptible mosquitoes were subsequently screened for kdr East and West mutations, and individually processed for microbial analysis using high throughput sequencing targeting the universal bacterial and archaeal 16S rRNA gene. RESULTS: 47 % of the samples tested (n = 133) were resistant, and of the 100 selected for further processing, 99 % were positive for kdr East and 1 % for kdr West. Overall, 84 bacterial taxa were detected across all mosquito samples, with 36 of these shared between resistant and susceptible mosquitoes. A total of 20 bacterial taxa were unique to the resistant mosquitoes and 28 were unique to the susceptible mosquitoes. There were significant differences in bacterial composition between resistant and susceptible individuals (PERMANOVA, pseudo-F = 2.33, P = 0.001), with presence of Sphingobacterium, Lysinibacillus and Streptococcus (all known pyrethroid-degrading taxa), and the radiotolerant Rubrobacter, being significantly associated with resistant mosquitoes. On the other hand, the presence of Myxococcus, was significantly associated with susceptible mosquitoes. CONCLUSIONS: This is the first report of distinct microbiota in An. gambiae s.s. associated with intense pyrethroid resistance. The findings highlight differentially abundant bacterial taxa between resistant and susceptible mosquitoes, and further suggest a microbe-mediated mechanism of insecticide resistance in mosquitoes. These results also indicate fixation of the kdr East mutation in this mosquito population, precluding further analysis of its associations with the mosquito microbiota, but presenting the hypothesis that any microbe-mediated mechanism of insecticide resistance would be likely of a metabolic nature. Overall, this study lays initial groundwork for understanding microbe-mediated mechanisms of insecticide resistance in African mosquito vectors of malaria, and potentially identifying novel microbial markers of insecticide resistance that could supplement existing vector surveillance tools.

Experiment 1

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Curated date: 2024/04/29

Curator: Idiaru angela

Revision editor(s): Idiaru angela

Subjects

Location of subjects: Kenya

Host species Species from which microbiome was sampled. Contact us to have more species added.: Anopheles gambiae

Body site Anatomical site where microbial samples were extracted from according to the Uber Anatomy Ontology: Body proper Body,Whole body,Body proper,body proper

Condition The experimental condition / phenotype studied according to the Experimental Factor Ontology: Insecticide insecticides,Insecticide,insecticide

Group 0 name Corresponds to the control (unexposed) group for case-control studies: permethrin susceptible mosquito

Group 1 name Corresponds to the case (exposed) group for case-control studies: permethrin resistant mosquito

Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group: Mosquitoes that were alive after the bioassay with permethrin insecticide were categorized as resistant

Group 0 sample size Number of subjects in the control (unexposed) group: 36

Group 1 sample size Number of subjects in the case (exposed) group: 39

Lab analysis

Sequencing type: 16S

16S variable region One or more hypervariable region(s) of the bacterial 16S gene: V3-V4

Sequencing platform Manufacturer and experimental platform used for quantifying microbial abundance: Illumina

Statistical Analysis

Data transformation Data transformation applied to microbial abundance measurements prior to differential abundance testing (if any).: relative abundances

Statistical test: LEfSe

Significance threshold p-value or FDR threshold used for differential abundance testing (if any): 0.05

MHT correction Have statistical tests be corrected for multiple hypothesis testing (MHT)?: No

LDA Score above Threshold for the linear discriminant analysis (LDA) score for studies using the popular LEfSe tool: 2

Alpha Diversity

Shannon Estimator of species richness and species evenness: more weight on species richness: unchanged

Signature 1

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Mark reviewed

Your review change was submitted

Needs review

Curated date: 2024/04/29

Curator: Idiaru angela

Revision editor(s): Idiaru angela

Source: Figure 5

Description: Differentially abundant bacterial genera between permethrin resistant and susceptible mosquitoes determined by Lefse analysis

Abundance in Group 1: increased abundance in permethrin resistant mosquito

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Sphingobacterium
Lysinibacillus
Streptococcus
Rhodospirillales
uncultured bacterium
unclassified Rhodospirillales
Alphaproteobacteria
Rubrobacteraceae
Rubrobacterales
Rubrobacter
Rubrobacteria
Actinomycetota