Assessment of the Impact of Potential Tetracycline Exposure on the Phenotype of Aedes aegypti OX513A: Implications for Field Use

Zoe Curtis,Pamela Gray,Marco Neira Oviedo,Kelly Matzen,Camilla Beech,Wilson F Jardim,Marco A F Locatelli,Derric Nimmo,Luke Alphey,Peter Winskill,Simon Warner,Mark Quentin Benedict

doi:10.1371/journal.pntd.0003999

Abstract

Background Aedes aegypti is the primary vector of dengue fever, a viral disease which has an estimated incidence of 390 million infections annually. Conventional vector control methods have been unable to curb the transmission of the disease. We have previously reported a novel method of vector control using a tetracycline repressible self-limiting strain of Ae. aegypti OX513A which has achieved >90% suppression of wild populations.Methodology/Principal FindingsWe investigated the impact of tetracycline and its analogues on the phenotype of OX513A from the perspective of possible routes and levels of environmental exposure. We determined the minimum concentration of tetracycline and its analogues that will allow an increased survivorship and found these to be greater than the maximum concentration of tetracyclines found in known Ae. aegypti breeding sites and their surrounding areas. Furthermore, we determined that OX513A parents fed tetracycline are unable to pre-load their progeny with sufficient antidote to increase their survivorship. Finally, we studied the changes in concentration of tetracycline in the mass production rearing water of OX513A and the developing insect.Conclusion/SignificanceTogether, these studies demonstrate that potential routes of exposure of OX513A individuals to tetracycline and its analogues in the environment are not expected to increase the survivorship of OX513A.

Highlights

Dengue fever is a viral infection, primarily transmitted by the mosquito Aedes aegypti, with an estimated incidence of 390 million infections annually [1]
Dengue fever is spread by the mosquito Aedes aegypti and the most effective method to limit the spread of dengue is to reduce the mosquito population
We have previously reported a transgenic strain of Ae. aegypti which results in >90% population suppression: males, which do not transmit disease, are released into the field carrying a self-limiting gene to mate with wild females, passing on the self-limiting gene which causes >95% progeny to die before becoming vectors of disease

Summary

Introduction

Dengue fever is a viral infection, primarily transmitted by the mosquito Aedes aegypti, with an estimated incidence of 390 million infections annually [1]. We have reported a novel method of vector control based on the sterile insect technique (SIT) [4,5,6] In this approach, males homozygous for a tetracycline repressible transgene, which confers the self-limiting trait to progeny are released into the environment where they search for and mate with wild females. Aedes aegypti is the primary vector of dengue fever, a viral disease which has an estimated incidence of 390 million infections annually. We have previously reported a novel method of vector control using a tetracycline repressible self-limiting strain of Ae. aegypti OX513A which has achieved >90% suppression of wild populations

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Discussion

Conclusion