Article
Insecticide resistance and genetic structure of Aedes aegypti populations from Rio de Janeiro State, Brazil
Registro en:
RAHMAN, Rafi Ur et al. Insecticide resistance and genetic structure of Aedes aegypti populations from Rio de Janeiro State, Brazil. PLOS Neglected Tropical Diseases, v. 15, n. 2, e0008492, p. 1-25, Feb. 2021.
1935-2727
10.1371/journal.pntd.0008492
1935-2735
Autor
Rahman, Rafi Ur
Cosme, Luciano Veiga
Costa, Monique Melo
Carrara, Luana
Lima, Jose´ Bento Pereira
Martins, Ademir Jesus
Resumen
Vector control largely relies on neurotoxic chemicals, and insecticide resistance (IR) directly
threatens their effectiveness. In some cases, specific alleles cause IR, and knowledge of
the genetic diversity and gene flow among mosquito populations is crucial to track their
arrival, rise, and spread. Here we evaluated Aedes aegypti populations’ susceptibility status,
collected in 2016 from six different municipalities of Rio de Janeiro state (RJ), to temephos,
pyriproxyfen, malathion, and deltamethrin. We collected eggs of Ae. aegypti in Campos dos
Goytacazes (Cgy), Itaperuna (Ipn), Iguaba Grande (Igg), Itaboraı´ (Ibr), Mangaratiba (Mgr),
and Vassouras (Vsr). We followed the World Health Organization (WHO) guidelines and
investigated the degree of susceptibility/resistance of mosquitoes to these insecticides. We
used the Rockefeller strain as a susceptible positive control. We genotyped the V1016I and
F1534C knockdown resistance (kdr) alleles using qPCR TaqMan SNP genotyping assay.
Besides, with the use of Ae. aegypti SNP-chip, we performed genomic population analyses
by genotyping more than 15,000 biallelic SNPs in mosquitoes from each population. We
added previous data from populations from other countries to evaluate the ancestry of RJ
populations.
All RJ Ae. aegypti populations were susceptible to pyriproxyfen and malathion and highly
resistant to deltamethrin. The resistance ratios for temephos was below 3,0 in Cgy, Ibr, and
Igg populations, representing the lowest rates since IR monitoring started in this Brazilian
region. We found the kdr alleles in high frequencies in all populations, partially justifying the
observed resistance to pyrethroid. Population genetics analysis showed that Ae. aegypti
revealed potential higher migration among some RJ localities and low genetic structure for
most of them. Future population genetic studies, together with IR data in Ae aegypti on a
broader scale, can help us predict the gene flow within and among the Brazilian States,
allowing us to track the dynamics of arrival and changes in the frequency of IR alleles, and
providing critical information to improving vector control program.