Identifying the fitness costs of a pyrethroid-resistant genotype in the major arboviral vector Aedes aegypti
Abstract Background Effective vector control measures are essential in a world where many mosquito-borne diseases have no vaccines or drug therapies available. Insecticidal tools remain the mainstay of most vector-borne disease management programmes, although their use for both agricultural and publ...
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| Format: | Article |
| Language: | English |
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BMC
2020-07-01
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| Series: | Parasites & Vectors |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13071-020-04238-4 |
| _version_ | 1818404270298365952 |
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| author | Lisa M. Rigby Gordana Rašić Christopher L. Peatey Leon E. Hugo Nigel W. Beebe Gregor J. Devine |
| author_facet | Lisa M. Rigby Gordana Rašić Christopher L. Peatey Leon E. Hugo Nigel W. Beebe Gregor J. Devine |
| author_sort | Lisa M. Rigby |
| collection | DOAJ |
| description | Abstract Background Effective vector control measures are essential in a world where many mosquito-borne diseases have no vaccines or drug therapies available. Insecticidal tools remain the mainstay of most vector-borne disease management programmes, although their use for both agricultural and public health purposes has resulted in selection for resistance. Despite this, little is known about the fitness costs associated with specific insecticide-resistant genotypes and their implications for the management of resistance. In Aedes aegypti, the primary vector of dengue, chikungunya, and Zika, the best-characterised resistance mechanisms are single-point mutations that protect the voltage-gated sodium channel from the action of pyrethroids. Methods We evaluated the fitness cost of two co-occurring, homozygous mutations (V1016G and S989P) by back-crossing a resistant strain of A. aegypti from Timor-Leste into a fully susceptible strain from Queensland. The creation of the backcross strain allowed us to isolate these kdr mutations in an otherwise susceptible genetic background. Results In comparison to the susceptible strain, the backcrossed colony exhibited longer larval development times (5 days, P < 0.001), 24% fewer mosquitoes reached the adult stage (P = 0.005), had smaller wing lengths (females, P = 0.019 and males, P = 0.007) and adult female mosquitoes had a shorter average lifespan (6 days, P < 0.0006). Conclusions These results suggest specific and significant fitness costs associated with the double homozygous V1016G/S989P genotype in the absence of insecticides. The susceptibility of a population may recover if the fitness costs of resistant genotypes can be emphasised through the use of insecticide rotations and mosaics or the presence of untreated spatial or temporal refuges. |
| first_indexed | 2024-12-14T08:37:29Z |
| format | Article |
| id | doaj.art-297411e98ca34a88984cccdba93d5913 |
| institution | Directory Open Access Journal |
| issn | 1756-3305 |
| language | English |
| last_indexed | 2024-12-14T08:37:29Z |
| publishDate | 2020-07-01 |
| publisher | BMC |
| record_format | Article |
| series | Parasites & Vectors |
| spelling | doaj.art-297411e98ca34a88984cccdba93d59132022-12-21T23:09:22ZengBMCParasites & Vectors1756-33052020-07-0113111210.1186/s13071-020-04238-4Identifying the fitness costs of a pyrethroid-resistant genotype in the major arboviral vector Aedes aegyptiLisa M. Rigby0Gordana Rašić1Christopher L. Peatey2Leon E. Hugo3Nigel W. Beebe4Gregor J. Devine5Australian Defence Force Malaria and Infectious Disease Institute, Gallipoli BarracksMosquito Control Laboratory, QIMR Berghofer Medical Research InstituteAustralian Defence Force Malaria and Infectious Disease Institute, Gallipoli BarracksMosquito Control Laboratory, QIMR Berghofer Medical Research InstituteSchool of Biological Sciences, University of QueenslandMosquito Control Laboratory, QIMR Berghofer Medical Research InstituteAbstract Background Effective vector control measures are essential in a world where many mosquito-borne diseases have no vaccines or drug therapies available. Insecticidal tools remain the mainstay of most vector-borne disease management programmes, although their use for both agricultural and public health purposes has resulted in selection for resistance. Despite this, little is known about the fitness costs associated with specific insecticide-resistant genotypes and their implications for the management of resistance. In Aedes aegypti, the primary vector of dengue, chikungunya, and Zika, the best-characterised resistance mechanisms are single-point mutations that protect the voltage-gated sodium channel from the action of pyrethroids. Methods We evaluated the fitness cost of two co-occurring, homozygous mutations (V1016G and S989P) by back-crossing a resistant strain of A. aegypti from Timor-Leste into a fully susceptible strain from Queensland. The creation of the backcross strain allowed us to isolate these kdr mutations in an otherwise susceptible genetic background. Results In comparison to the susceptible strain, the backcrossed colony exhibited longer larval development times (5 days, P < 0.001), 24% fewer mosquitoes reached the adult stage (P = 0.005), had smaller wing lengths (females, P = 0.019 and males, P = 0.007) and adult female mosquitoes had a shorter average lifespan (6 days, P < 0.0006). Conclusions These results suggest specific and significant fitness costs associated with the double homozygous V1016G/S989P genotype in the absence of insecticides. The susceptibility of a population may recover if the fitness costs of resistant genotypes can be emphasised through the use of insecticide rotations and mosaics or the presence of untreated spatial or temporal refuges.http://link.springer.com/article/10.1186/s13071-020-04238-4Aedes aegyptiPyrethroidInsecticide resistanceBackcrossTimor-Leste |
| spellingShingle | Lisa M. Rigby Gordana Rašić Christopher L. Peatey Leon E. Hugo Nigel W. Beebe Gregor J. Devine Identifying the fitness costs of a pyrethroid-resistant genotype in the major arboviral vector Aedes aegypti Parasites & Vectors Aedes aegypti Pyrethroid Insecticide resistance Backcross Timor-Leste |
| title | Identifying the fitness costs of a pyrethroid-resistant genotype in the major arboviral vector Aedes aegypti |
| title_full | Identifying the fitness costs of a pyrethroid-resistant genotype in the major arboviral vector Aedes aegypti |
| title_fullStr | Identifying the fitness costs of a pyrethroid-resistant genotype in the major arboviral vector Aedes aegypti |
| title_full_unstemmed | Identifying the fitness costs of a pyrethroid-resistant genotype in the major arboviral vector Aedes aegypti |
| title_short | Identifying the fitness costs of a pyrethroid-resistant genotype in the major arboviral vector Aedes aegypti |
| title_sort | identifying the fitness costs of a pyrethroid resistant genotype in the major arboviral vector aedes aegypti |
| topic | Aedes aegypti Pyrethroid Insecticide resistance Backcross Timor-Leste |
| url | http://link.springer.com/article/10.1186/s13071-020-04238-4 |
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