RETRACTED ARTICLE: First report of the Phe1534Cyskdr mutation in natural populations of Aedes albopictusfrom Brazil

Abstract

BackgroundKnockdown resistance (kdr), caused by alterations in the voltage-gated sodium channel (NaV), is one of the mechanisms responsible for pyrethroid (PY) resistance. In the Asian tiger mosquito, Aedes albopictus, at least four different mutations were described in the IIIS6 NaV segment in populations from Asia, North America and Europe. In contrast, in Aedes aegypti at least 12 non-synonymous mutations have been reported at nine different codons, mostly in the IIS6 and IIIS6 NaV segments. The Phe1534Cys kdr mutation in the IIIS6 NaV segment is the most prevalent in populations of Ae. aegypti worldwide, also found in Ae. albopictus from Singapore. Herein, we investigated the DNA diversity corresponding to the IIS6 and IIIS6 NaV segments in natural populations of Ae. albopictus from Brazil.MethodsDNA from eight Brazilian Ae. albopictus natural populations were individually extracted and pooled by states of origin, amplified, cloned and sequenced for the corresponding IIS6 and IIIS6 NaV segments. Additionally, samples from each location were individually genotyped by an allelic specific PCR (AS-PCR) approach to obtain the genotypic and allelic frequencies for the 1534 NaV site.ResultsNo non-synonymous substitutions were observed in the IIS6 sequences. However, the Phe1534Cys kdr mutation was evidenced in the Ae. albopictus NaV IIIS6 segment sequences from Paraná (PR) and Rondônia (RO) states, but not from Mato Grosso (MT) state. The 1534Cyskdr allele varied from 3% (Marilena/PR and Porto Velho/RO) to 10% (Foz do Iguaçu/PR). To our knowledge, this paper reports the first occurrence and provides distribution data of a possible kdr mutation in Ae. albopictus in South America.ConclusionThe emergence of a likely kdr mutation in Ae. albopitus natural populations is a signal of alert for vector control measures since PY are the most popular insecticides adopted by residents. Additionally, once the kdr allele is present, its frequency tends to increase faster under exposition to those compounds. Although the Asian tiger mosquito is not incriminated as an important vector of dengue, chikungunya and Zika viruses in South America, its importance in this regard has been extensively discussed since Ae. albopictus is rapidly spreading and can also migrate between sylvatic and urban environments. Therefore, insecticide resistance monitoring initiatives should also be extended to Ae. albopictus in Brazil in order to maintain chemical compounds as an efficient vector control tool when needed.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-017-2089-5) contains supplementary material, which is available to authorized users.

Phenotypic and genotypic pyrethroid resistance ofAedes albopictus, with focus on the 2017 chikungunya outbreak in Italy

“…Mutation F1534C – reported previously in Ae. albopictus from Singapore, China, Greece and Brazil – was only found in the population from Athens, Greece (where it had already been detected by Xu et al ) and not in the other populations analysed. Notably, allele C1534 is the most widespread mutation conferring pyrethroid resistance in Ae.…”

Population genomics of the Asian tiger mosquito, Aedes albopictus: insights into the recent worldwide invasion

“…Additionally, the populations from Greece, Brazil, and Singapore share the same F1534C kdr mutation. This mutation may confer resistance to pyrethroids and DDT insecticides (Aguirre‐Obando, Martins, & Navarro‐Silva, ; Kasai et al., ; Xu et al., ). Other substitutions (F1534L and F1534S) in the same kdr codon were found in the USA (Marcombe, Farajollahi, Healy, Clark, & Fonseca, ; Xu et al., ) and China (Chen et al., ; Xu et al., ).…”

Phenotypic and molecular analysis of insecticide resistance in Aedes albopictus populations from Greece

“…Previous studies also reported relatively high mutation frequencies (reaching 66%) in populations sampled from the Attica region [47,48]. To date, kdr F1534C has also been recorded in Brazil [49], Singapore, Vietnam [50] and China [51], while other substitutions in the same genomic locus, F1534L and F1534S, also associated with pyrethroid resistance, have been identified in the USA, China, Vietnam and Italy [47,[50][51][52].…”