scholarly journals Sodium Channel Mutations and Pyrethroid Resistance in Aedes aegypti

Insects ◽  
2016 ◽  
Vol 7 (4) ◽  
pp. 60 ◽  
Author(s):  
Yuzhe Du ◽  
Yoshiko Nomura ◽  
Boris Zhorov ◽  
Ke Dong
2020 ◽  
Author(s):  
Juli R. Wuliandari ◽  
Ary A. Hoffmann ◽  
Warsito Tantowijoyo ◽  
Nancy M. Endersby-Harshman

Abstract Background : In the inner city of Yogyakarta, Indonesia, insecticide resistance is expected in the main dengue vector, Aedes aegypti , because of the intensive local application of pyrethroid insecticides. However, detailed information about the nature of resistance in this species is required to assist the release of Wolbachia mosquitoes in a dengue control program so that we can ensure that insecticide resistance in the strain of Ae. aegypti being released matches that of the background population. Methods: High-resolution melt genotyping was used to screen for kdr mutations associated with pyrethroid resistance in the voltage-sensitive sodium channel (V SSC ) gene in Ae. aegypti of some areas in the inner city of Yogyakarta. Results: The results show that the V1016G mutation predominated, with individuals homozygous for the 1016G allele at a frequency of 82.1% and the mutant allele G at a frequency of 92%. Two patterns of co-occurrence of mutations were detected in this study, homozygous individuals V1016G/S989P; and heterozygous individuals V1016G/F1534C/S989P. We found the simultaneous occurrence of kdr mutations V1016G and F1534C at all collection sites, but not within individual mosquitoes. Homozygous mutants at locus 1016 were homozygous wildtype at locus 1534 and vice versa, and heterozygous V1016G were also heterozygous for F1534C. The most common tri-locus genotype co-occurrences were homozygous mutant 1016GG and homozygous wild-type FF1534, combined with homozygous mutant 989PP (GG/FF/PP) at a frequency of 38.28%. Conclusions: Given the relatively small differences in frequency of resistance alleles across the city area, locality variations in resistance should have minor implications for the success of Wolbachia mosquito trials being undertaken in the Yogyakarta area.


2018 ◽  
Author(s):  
Alden S. Estep ◽  
Neil D. Sanscrainte ◽  
Christy M. Waits ◽  
Sarah J. Bernard ◽  
Aaron M. Lloyd ◽  
...  

AbstractRecent outbreaks of locally transmitted dengue and Zika viruses in Florida have placed more emphasis on the importance of integrated vector management plans for Aedes aegypti (L.) and Aedes albopictus Skuse. Adulticiding, primarily with pyrethroids, can be the best option available for the immediate control of potentially arbovirus-infected mosquitoes during outbreak situations. While pyrethroid resistance is common in Ae. aegypti worldwide and testing is recommended by CDC and WHO, resistance to this class of products has not been widely examined or quantified in Florida. To address this information gap, we performed the first study to quantify both pyrethroid resistance and genetic markers of pyrethroid resistance in Ae. aegypti and Ae. albopictus strains in Florida. Using direct topical application, we examined 21 Ae. aegypti strains from 9 counties and found permethrin resistance (resistance ratio (RR)=6-61-fold) in all strains when compared to the susceptible ORL1952 control strain. Permethrin resistance in five strains of Ae. albopictus was very low (RR<1.6) even when collected from the same containers producing resistant Ae. aegypti. Characterization of two sodium channel kdr alleles associated with pyrethroid-resistance showed widespread distribution in 62 strains of Ae. aegypti. The 1534 phenylalanine to cysteine (F1534C) single nucleotide polymorphism SNP was fixed or nearly fixed in all strains regardless of RR. We observed much more variation in the 1016 valine to isoleucine (V1016I) allele and observed that increasing frequency of the homozygous V1016I allele correlates strongly with increased RR (Pearson corr= 0.905). In agreement with previous studies, we observed a very low frequency of three kdr genotypes, IIFF, VIFF, and IIFC. In this study, we provide a statewide examination of pyrethroid resistance, and demonstrate that permethrin resistance and the genetic markers for resistance are widely present in FL Ae. aegypti. Resistance testing should be included in an effective management program.Author SummaryAedes aegypti and Aedes albopictus can vector a variety of arboviruses that cause diseases and are thus a public health concern. Pyrethroid insecticide resistance is common in Aedes aegypti in many locations worldwide and can adversely affect vector control operations. However, the resistance status of these vectors in Florida is largely unreported and recent local transmission of dengue and Zika viruses has made this information critical for effective control operations. In this study, we showed that permethrin resistance and two common SNPs of the voltage gated sodium channel (V1016I and F1534C) previously associated with pyrethroid resistance were widely present in Florida Aedes aegypti strains. We also observed a strong correlation between the IICC genotype and RR as determined by topical application, which suggests, as have others, that kdr frequency may be a useful indicator of resistance in Aedes aegypti.


2007 ◽  
Vol 16 (6) ◽  
pp. 785-798 ◽  
Author(s):  
K. Saavedra-Rodriguez ◽  
L. Urdaneta-Marquez ◽  
S. Rajatileka ◽  
M. Moulton ◽  
A. E. Flores ◽  
...  

2020 ◽  
Author(s):  
Juli R. Wuliandari ◽  
Ary A. Hoffmann ◽  
Warsito Tantowijoyo ◽  
Nancy M. Endersby-Harshman

Abstract Background: In the inner city of Yogyakarta, Indonesia, insecticide resistance is expected in the main dengue vector, Aedes aegypti, because of the intensive local application of pyrethroid insecticides. However, detailed information about the nature of resistance in this species is required to assist the release of Wolbachia mosquitoes in a dengue control program so that we can ensure that insecticide resistance in the strain of Ae. aegypti being released matches that of the background population.Methods: High-resolution melt genotyping was used to screen for kdr mutations associated with pyrethroid resistance in the voltage-sensitive sodium channel (VSSC) gene in Ae. aegypti of some areas in the inner city of Yogyakarta.Results: The results show that the V1016G mutation predominated, with individuals homozygous for the 1016G allele at a frequency of 82.1% and the mutant allele G at a frequency of 92%. Two patterns of co-occurrence of mutations were detected in this study, homozygous individuals V1016G/S989P; and heterozygous individuals V1016G/F1534C/S989P. We found the simultaneous occurrence of kdr mutations V1016G and F1534C at all collection sites, but not within individual mosquitoes. Homozygous mutants at locus 1016 were homozygous wildtype at locus 1534 and vice versa, and heterozygous V1016G were also heterozygous for F1534C. The most common tri-locus genotype co-occurrences were homozygous mutant 1016GG and homozygous wild-type FF1534, combined with homozygous mutant 989PP (GG/FF/PP) at a frequency of 38.28%.Conclusions: Given the relatively small differences in frequency of resistance alleles across the city area, locality variations in resistance should have minor implications for the success of Wolbachia mosquito trials being undertaken in the Yogyakarta area.


2018 ◽  
Vol 10 (3) ◽  
pp. 250-5 ◽  
Author(s):  
Budi Mulyaningsih ◽  
Sitti Rahmah Umniyati ◽  
Tri Baskoro Tunggul Satoto ◽  
Ernaningsih Ernaningsih ◽  
Dwi Aris Agung Nugrahaningsih

BACKGROUND: Aedes aegypti is a vector of several pathogens including dengue virus. Vector control is an effective way to break the transmission but unfortunately constant use of insecticides ultimately causes vector resistance. Pyrethroids have been used for about 15 years to combat Ae. aegypti in Yogyakarta Province, Indonesia. Single amino acid substitutions in the voltagegated sodium channel associated with pyrethroid resistance constitute one of the main causative factors of knockdown resistance (kdr). The aim of this study is to detect resistant status to cypermetrine and polymorphism on the voltagegated sodium channel gene of Ae. aegypti from 2 dengue endemic areas in Yogyakarta Province (Yogyakarta city and Sleman district).METHODS: Pyrethroid resistance in Ae. aegypti mosquitoes was detected by using CDC Bottle Bioassay. To detect the polymorphism on the voltage-gated sodium channel gene of Ae. aegypti analyses were conducted by using PCR and direct DNA squencing with primers AaSCF1 and AaSCR4 for S989P, I1011M (or V), L1014F sites, and AaSCF7 and AaSCR7 for the F1534C site.RESULTS: According to bioassay, the results for Ae. aegypti from Yogyakarta city (93% mortality) and Sleman district (88% mortality) suggest the possibility of resistance to cypermethrin. We observed polymorphism on voltagegated sodium channel gene on site F1534C (heterozygous).CONCLUSION: The findings provide early evidence that the use of cypermethrin (pyrethroids) in Yogyakarta city and Sleman district, Yogyakarta Province, Indonesia is reducing its effectiveness to control Ae. aegypti. Recommendations include additional tests for confirmation.KEYWORDS: Aedes aegypti, dengue virus, cypermethrin, Bioassay, Yogyakarta


2020 ◽  
Vol 104 (2) ◽  
Author(s):  
Mengli Chen ◽  
Yuzhe Du ◽  
Yoshiko Nomura ◽  
Boris S. Zhorov ◽  
Ke Dong

2019 ◽  
Author(s):  
Farah Z. Vera-Maloof ◽  
Karla Saavedra-Rodriguez ◽  
Rosa P. Penilla-Navarro ◽  
Americo D. Rodriguez-Ramirez ◽  
Felipe Dzul ◽  
...  

AbstractBackgroundResistance to pyrethroid insecticides in Aedes aegypti has become widespread after almost two decades of their frequent use to reduce arbovirus transmission. Despite this, use of pyrethroids continues because they are relatively inexpensive and because of their low human toxicity. Resistance management has been proposed as a means to retain the use of pyrethroids in natural populations. A key component of resistance management assumes that there is a negative fitness associated with resistance alleles so that when insecticides are removed, resistance alleles will decline in frequency. At least three studies in Ae. aegypti have demonstrated a decrease in pyrethroid resistance once the insecticide is removed.Methods/Principal FindingsThe present study aims to evaluate variation in the loss of pyrethroid resistance among newly established laboratory populations of Ae. aegypti from Mexico. Eight field collections were maintained for up to eight generations and we recorded changes in the frequencies of mutations at the V1,016I locus and at the F1,534C locus in the voltage gated sodium channel (VGSC) gene. I1,016 and C1,534 confer resistance. We also examined resistance ratios (RR) with type 1 and 2 pyrethroids.Conclusions/SignificanceWe demonstrate that, in general, the frequency of the Ae. aegypti pyrethroid resistance alleles I1,016 and C1,534 decline when they are freed from pyrethroid pressure in the laboratory. However, the pattern of decline is strain dependent. In agreement with earlier studies, RR was positively correlated with I1,016 resistant allele frequencies and showed significant protection against permethrin, and deltamethrin whereas F1534C showed protection against permethrin but not against deltamethrin.Author SummaryThe author is interested in the evolution of genes that confer resistance to insecticides, especially when this evolution affects binding of insecticides to their target site. The Voltage Gated Sodium Channel gene represents an excellent opportunity to understand how mutations at the target site(s) affect the evolution of resistance in many different pest insect species including Aedes aegypti, the primary vector of Dengue Virus, Yellow Fever, Zika and Chikungunya arboviruses.


Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 71
Author(s):  
Tse-Yu Chen ◽  
Chelsea T. Smartt ◽  
Dongyoung Shin

Aedes aegypti, as one of the vectors transmitting several arboviruses, is the main target in mosquito control programs. Permethrin is used to control mosquitoes and Aedes aegypti get exposed due to its overuse and are now resistant. The increasing percentage of permethrin resistant Aedes aegypti has become an important issue around the world and the potential influence on vectorial capacity needs to be studied. Here we selected a permethrin resistant (p-s) Aedes aegypti population from a wild Florida population and confirmed the resistance ratio to its parental population. We used allele-specific PCR genotyping of the V1016I and F1534C sites in the sodium channel gene to map mutations responsible for the resistance. Two important factors, survival rate and vector competence, that impact vectorial capacity were checked. Results indicated the p-s population had 20 times more resistance to permethrin based on LD50 compared to the parental population. In the genotyping study, the p-s population had more homozygous mutations in both mutant sites of the sodium channel gene. The p-s adults survived longer and had a higher dissemination rate for dengue virus than the parental population. These results suggest that highly permethrin resistant Aedes aegypti populations might affect the vectorial capacity, moreover, resistance increased the survival time and vector competence, which should be of concern in areas where permethrin is applied.


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