Author
Shinji Kasai
Other affiliations: University of Tsukuba, Cornell University
Bio: Shinji Kasai is an academic researcher from National Institutes of Health. The author has contributed to research in topics: Knockdown resistance & Pyrethroid. The author has an hindex of 33, co-authored 92 publications receiving 3209 citations. Previous affiliations of Shinji Kasai include University of Tsukuba & Cornell University.
Topics: Knockdown resistance, Pyrethroid, Aedes aegypti, Permethrin, Medicine
Papers published on a yearly basis
Papers
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TL;DR: The status of pyrethroid resistance in A. aegypti and A. albopictus is reviewed, mechanisms of resistance, fitness costs associated with resistance alleles and suggestions for future research are presented.
247 citations
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Cornell University1, Washington University in St. Louis2, University of Groningen3, University of Zurich4, University of Illinois at Urbana–Champaign5, Oxford Brookes University6, Auburn University7, University of Houston8, United States Department of Health and Human Services9, University of Tennessee Health Science Center10, Harvard University11, University College London12
TL;DR: The house fly genome provides a rich resource for enabling work on innovative methods of insect control, for understanding the mechanisms of insecticide resistance, genetic adaptation to high pathogen loads, and for exploring the basic biology of this important pest.
Abstract: Adult house flies, Musca domestica L., are mechanical vectors of more than 100 devastating diseases that have severe consequences for human and animal health. House fly larvae play a vital role as decomposers of animal wastes, and thus live in intimate association with many animal pathogens. We have sequenced and analyzed the genome of the house fly using DNA from female flies. The sequenced genome is 691 Mb. Compared with Drosophila melanogaster, the genome contains a rich resource of shared and novel protein coding genes, a significantly higher amount of repetitive elements, and substantial increases in copy number and diversity of both the recognition and effector components of the immune system, consistent with life in a pathogen-rich environment. There are 146 P450 genes, plus 11 pseudogenes, in M. domestica, representing a significant increase relative to D. melanogaster and suggesting the presence of enhanced detoxification in house flies. Relative to D. melanogaster, M. domestica has also evolved an expanded repertoire of chemoreceptors and odorant binding proteins, many associated with gustation. This represents the first genome sequence of an insect that lives in intimate association with abundant animal pathogens. The house fly genome provides a rich resource for enabling work on innovative methods of insect control, for understanding the mechanisms of insecticide resistance, genetic adaptation to high pathogen loads, and for exploring the basic biology of this important pest. The genome of this species will also serve as a close out-group to Drosophila in comparative genomic studies.
239 citations
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TL;DR: In vivo metabolism studies showed that the SP strain excreted permethrin metabolites more rapidly than a susceptible SMK strain, and in vitro metabolism studies indicated an association of P450s with resistance, suggesting that cytochrome P450 monooxygenases (P450s) play an important role in resistance development.
Abstract: Aedes aegypti is the major vector of yellow and dengue fevers. After 10 generations of adult selection, an A. aegypti strain (SP) developed 1650-fold resistance to permethrin, which is one of the most widely used pyrethroid insecticides for mosquito control. SP larvae also developed 8790-fold resistance following selection of the adults. Prior to the selections, the frequencies of V1016G and F1534C mutations in domains II and III, respectively, of voltage-sensitive sodium channel (Vssc, the target site of pyrethroid insecticide) were 0.44 and 0.56, respectively. In contrast, only G1016 alleles were present after two permethrin selections, indicating that G1016 can more contribute to the insensitivity of Vssc than C1534. In vivo metabolism studies showed that the SP strain excreted permethrin metabolites more rapidly than a susceptible SMK strain. Pretreatment with piperonyl butoxide caused strong inhibition of excretion of permethrin metabolites, suggesting that cytochrome P450 monooxygenases (P450s) play an important role in resistance development. In vitro metabolism studies also indicated an association of P450s with resistance. Microarray analysis showed that multiple P450 genes were over expressed during the larval and adult stages in the SP strain. Following quantitative real time PCR, we focused on two P450 isoforms, CYP9M6 and CYP6BB2. Transcription levels of these P450s were well correlated with the rate of permethrin excretion and they were certainly capable of detoxifying permethrin to 4′-HO-permethrin. Over expression of CYP9M6 was partially due to gene amplification. There was no significant difference in the rate of permethrin reduction from cuticle between SP and SMK strains.
176 citations
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TL;DR: The F455W replacement in the Ace2 gene is solely responsible for the insecticide-insensitivity of AChE in TYM mosquitoes.
159 citations
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Pasteur Institute1, Foundation for Research & Technology – Hellas2, Agricultural University of Athens3, Centre national de la recherche scientifique4, Liverpool School of Tropical Medicine5, Rutgers University6, Institut de recherche pour le développement7, National Institute of Malaria Research8, University of the Sciences9, Oswaldo Cruz Foundation10, National Institutes of Health11
TL;DR: A framework for the implementation of IRM strategies for Aedes mosquito vectors is proposed based on the lessons taken from resistance strategies used for other vector species and agricultural pests, and the value of existing tools for resistance monitoring is evaluated.
Abstract: Background
The landscape of mosquito-borne disease risk has changed dramatically in recent decades, due to the emergence and reemergence of urban transmission cycles driven by invasive Aedes aegypti and Ae. albopictus. Insecticide resistance is already widespread in the yellow fever mosquito, Ae. Aegypti; is emerging in the Asian tiger mosquito Ae. Albopictus; and is now threatening the global fight against human arboviral diseases such as dengue, yellow fever, chikungunya, and Zika. Because the panel of insecticides available for public health is limited, it is of primary importance to preserve the efficacy of existing and upcoming active ingredients. Timely implementation of insecticide resistance management (IRM) is crucial to maintain the arsenal of effective public health insecticides and sustain arbovirus vector control.
Methodology and principal findings
This Review is one of a series being generated by the Worldwide Insecticide resistance Network (WIN) and aims at defining the principles and concepts underlying IRM, identifying the main factors affecting the evolution of resistance, and evaluating the value of existing tools for resistance monitoring. Based on the lessons taken from resistance strategies used for other vector species and agricultural pests, we propose a framework for the implementation of IRM strategies for Aedes mosquito vectors.
Conclusions and significance
Although IRM should be a fixture of all vector control programs, it is currently often absent from the strategic plans to control mosquito-borne diseases, especially arboviruses. Experiences from other public health disease vectors and agricultural pests underscore the need for urgent action in implementing IRM for invasive Aedes mosquitoes. Based on a plan developed for malaria vectors, here we propose some key activities to establish a global plan for IRM in Aedes spp.
Author summary
Arthropod-borne viruses transmitted by Aedes aegypti and Ae. albopictus represent a major public health concern at a global scale. The insecticidal treatments exerted on both species have selected for various resistance mechanisms within wild populations. Although the impact of insecticide resistance on the efficacy of vector control operations remains broadly unknown, it is of primary importance to implement strategies for preserving the efficacy of treatments and reducing the pathogen transmission during epidemics. For this purpose, there are urgent needs for new tools for vector control and insecticide resistance monitoring to improve the management of insecticide resistance in Aedes species.
139 citations
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TL;DR: The genomic changes that lead to amplification, overexpression, and coding sequence variation in the three major groups of genes encoding metabolic enzymes, i.e., cytochrome P450 monooxygenases (P450s), esterases, and glutathione-S-transferases (GSTs), are the focus of this review.
Abstract: Xenobiotic resistance in insects has evolved predominantly by increasing the metabolic capability of detoxificative systems and/or reducing xenobiotic target site sensitivity. In contrast to the limited range of nucleotide changes that lead to target site insensitivity, many molecular mechanisms lead to enhancements in xenobiotic metabolism. The genomic changes that lead to amplification, overexpression, and coding sequence variation in the three major groups of genes encoding metabolic enzymes, i.e., cytochrome P450 monooxygenases (P450s), esterases, and glutathione-S-transferases (GSTs), are the focus of this review. A substantial number of the adaptive genomic changes associated with insecticide resistance that have been characterized to date are transposon mediated. Several lines of evidence suggest that P450 genes involved in insecticide resistance, and perhaps insecticide detoxification genes in general, may share an evolutionary association with genes involved in allelochemical metabolism. Differences in the selective regime imposed by allelochemicals and insecticides may account for the relative importance of regulatory or structural mutations in conferring resistance.
1,642 citations
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TL;DR: State-of-the-art information on resistance in insect vectors of disease is reviewed and new strategies to develop novel strategies with which to truly manage resistance are proposed.
Abstract: ▪ Abstract Insecticide resistance is an increasing problem in many insect vectors of disease Our knowledge of the basic mechanisms underlying resistance to commonly used insecticides is well established Molecular techniques have recently allowed us to start and dissect most of these mechanisms at the DNA level The next major challenge will be to use this molecular understanding of resistance to develop novel strategies with which we can truly manage resistance State-of-the-art information on resistance in insect vectors of disease is reviewed in this context
1,405 citations
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TL;DR: This paper reviews what is currently known about insecticide resistance conferred by metabolic or target site changes in mosquitoes.
1,011 citations
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TL;DR: This review begins by presenting background information about P450s, the role of monooxygenases in insects, and the different techniques that have been used to isolate individual insect P 450s, then discusses the importance of these studies for development of effective insecticide resistance management strategies.
697 citations