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Enayati A, Valadan R, Bagherzadeh M, Cheraghpour M, Nikookar SH, Fazeli-Dinan M, Hosseini-Vasoukolaei N, Sahraei Rostami F, Shabani Kordshouli R, Raeisi A, Nikpour F, Mirolyaei A, Bagheri F, Sedaghat MM, Zaim M, Weetman D, Hemigway J. Kdr genotyping and the first report of V410L and V1016I kdr mutations in voltage-gated sodium channel gene in Aedes aegypti (Diptera: Culicidae) from Iran. Parasit Vectors 2024; 17:34. [PMID: 38273349 PMCID: PMC10811842 DOI: 10.1186/s13071-024-06123-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 01/08/2024] [Indexed: 01/27/2024] Open
Abstract
BACKGROUND Aedes aegypti is the main vector of arboviral diseases worldwide. The species invaded and became established in southern Iran in 2020. Insecticide-based interventions are primarily used for its control. With insecticide resistance widespread, knowledge of resistance mechanisms is vital for informed deployment of insecticidal interventions, but information from Iranian Ae. aegypti is lacking. METHODS Fifty-six Ae. aegypti specimens were collected from the port city of Bandar Lengeh in Hormozgan Province in the South of Iran in 2020 and screened for kdr mutations. The most common kdr mutations in Latin America and Asia (V410L, S989P, V1016G/I and F1534C), especially when present in combinations, are highly predictive of DDT and pyrethroid resistance were detected. Phylogenetic analyses based on the diversity of S989P and V1016G/I mutations were undertaken to assess the phylogeography of these kdr mutations. RESULTS Genotyping all four kdr positions of V410L, S989P, V1016G/I and F1534C revealed that only 16 out of the 56 (28.57%) specimens were homozygous wild type for all kdr mutation sites. Six haplotypes including VSVF (0.537), VSVC (0.107), LSVF (0.016), LSIF (0.071), VPGC (0.257) and LPGC (0.011) were detected in this study. For the first time, 11 specimens harbouring the V410L mutation, and 8 samples with V1016I mutation were found. V410L and V1016I were coincided in 8 specimens. Also, six specimens contained 1016G/I double mutation which was not reported before. CONCLUSIONS The relatively high frequency of these kdr mutations in Iranian Ae. aegypti indicates a population exhibiting substantial resistance to pyrethroid insecticides, which are used widely in control operations and household formulations. The detection of the 410L/1016I kdr mutant haplotype in Iranian Ae. aegypti suggests possible convergence of invasive populations from West Africa or Latin America. However, as Iran has very limited maritime/air connections with those African countries, a Latin American origin for the invasive Ae. aegypti in Iran is more plausible.
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Affiliation(s)
- Ahmadali Enayati
- Department of Medical Entomology and Vector Control, School of Public Health and Health Sciences Research Center, Mazandaran University of Medical Sciences, Sari, Iran.
| | - Reza Valadan
- Department of Immunology and Molecular and Cellular Biology Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mahboobeh Bagherzadeh
- Department of Medical Entomology and Vector Control, School of Public Health, Student Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mohammad Cheraghpour
- Department of Medical Entomology and Vector Control, School of Public Health, Student Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Seyed Hassan Nikookar
- Health Sciences Research Center, Department of Medical Entomology and Vector Control, School of Public Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mahmoud Fazeli-Dinan
- Health Sciences Research Center, Department of Medical Entomology and Vector Control, School of Public Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Nasibeh Hosseini-Vasoukolaei
- Department of Medical Entomology and Vector Control, School of Public Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Farzaneh Sahraei Rostami
- Department of Medical Entomology and Vector Control, School of Public Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Razieh Shabani Kordshouli
- Department of Medical Entomology and Vector Control, School of Public Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ahmad Raeisi
- Vector Borne Diseases Control Department, Iran CDC, Ministry of Health and Medical Education, Tehran, Iran
- Department of Medical Parasitology & Mycology, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Nikpour
- Vector Borne Diseases Control Department, Iran CDC, Ministry of Health and Medical Education, Tehran, Iran
- Department of Environmental Chemical Pollutants and Pesticides, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Abdolreza Mirolyaei
- Vector Borne Diseases Control Department, Iran CDC, Ministry of Health and Medical Education, Tehran, Iran
| | - Fatemeh Bagheri
- Hormozgan Provincial Health Center, Department of Communicable Diseases Control, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Mohammad Mehdi Sedaghat
- Department of Medical Entomology and Vector Control, Tehran University of Medical Sciences, Tehran, Iran
| | - Morteza Zaim
- Department of Medical Entomology and Vector Control, Tehran University of Medical Sciences, Tehran, Iran
| | - David Weetman
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Janet Hemigway
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
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Herath JMMK, De Silva WAPP, Weeraratne TC, Karunaratne SHPP. Efficacy of the insect growth regulator novaluron in the control of dengue vector mosquitoes Aedes aegypti and Ae. albopictus. Sci Rep 2024; 14:1988. [PMID: 38263389 PMCID: PMC10805727 DOI: 10.1038/s41598-024-52384-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 01/18/2024] [Indexed: 01/25/2024] Open
Abstract
Insect Growth Regulator (IGR) novaluron is an alternative to synthetic neuro-inhibitory insecticides. Present study was designed to assess appropriate dosages of novaluron for dengue vector control. Larvae of Aedes aegypti and Ae. albopictus were exposed to a concentration series of novaluron (Rimon EC10) for two fixed exposure periods of 7-days and 14-days to determined LC50 and LC99 values. Inhibition of adult emergence (IE50 and IE99) was determined by a 14-day exposure. Semi-field experiments were conducted by exposing cohorts of Ae. aegypti larvae to IE99, 2 × IE99 and 10 × IE99 novaluron concentrations in water storage buckets (10 L) and plastic barrels (200 L). For the 7-day exposure, LC50 values were 0.047-0.049 ppm and LC99 were 0.144-0.151 ppm. For 14-day exposure, these values were 0.002-0.005 ppm and 0.006-0.01 ppm respectively. For both species, IE99 was 0.001 ppb under semi-field conditions, and was effective for nearly 2 months. Novaluron concentration 0.01 ppb was effective up to 3 months, with an IE of 89-95%. Authorities should critically review a reduction of the presently recommended field dosage of 200 ppm novaluron by × 100 or more. This would provide the same efficacy but mitigate environmental pollution, development of vector resistance, and financial losses.
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Affiliation(s)
- J M Manel K Herath
- Entomological Surveillance Unit, Office of Regional Director of Health Services, Kurunegala, Sri Lanka
- Postgraduate Institute of Science, University of Peradeniya, Peradeniya, Sri Lanka
| | | | - Thilini C Weeraratne
- Department of Zoology, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka
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Mendis BAN, Peiris V, Harshani WAK, Fernando HSD, de Silva BGDNK. Fine-scale monitoring of insecticide resistance in Aedes aegypti (Diptera: Culicidae) from Sri Lanka and modeling the phenotypic resistance using rational approximation. Parasit Vectors 2024; 17:18. [PMID: 38216956 PMCID: PMC10785423 DOI: 10.1186/s13071-023-06100-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 12/16/2023] [Indexed: 01/14/2024] Open
Abstract
BACKGROUND The unplanned and intensified use of insecticides to control mosquito-borne diseases has led to an upsurge of resistance to commonly used insecticides. Aedes aegypti, the main vector of dengue, chikungunya, and Zika virus, is primarily controlled through the application of adulticides (pyrethroid insecticides) and larvicides (temephos). Fine spatial-scale analysis of resistance may reveal important resistance-related patterns, and the application of mathematical models to determine the phenotypic resistance status lessens the cost and usage of resources, thus resulting in an enhanced and successful control program. METHODS The phenotypic resistance for permethrin, deltamethrin, and malathion was monitored in the Ae. aegypti populations using the World Health Organization (WHO) adult bioassay method. Mosquitoes' resistance to permethrin and deltamethrin was evaluated for the commonly occurring base substitutions in the voltage-gated sodium channel (vgsc) gene. Rational functions were used to determine the relationship between the kdr alleles and the phenotypic resistant percentage of Ae. aegypti in Sri Lanka. RESULTS The results of the bioassays revealed highly resistant Ae. aegypti populations for the two pyrethroid insecticides (permethrin and deltamethrin) tested. All populations were susceptible to 5% malathion insecticide. The study also revealed high frequencies of C1534 and G1016 in all the populations studied. The highest haplotype frequency was detected for the haplotype CC/VV, followed by FC/VV and CC/VG. Of the seven models obtained, this study suggests the prediction models using rational approximation considering the C allele frequencies and the total of C, G, and P allele frequencies and phenotypic resistance as the best fits for the area concerned. CONCLUSIONS This is the first study to our knowledge to provide a model to predict phenotypic resistance using rational functions considering kdr alleles. The flexible nature of the rational functions has revealed the most suitable association among them. Thus, a general evaluation of kdr alleles prior to insecticide applications would unveil the phenotypic resistance percentage of the wild mosquito population. A site-specific strategy is recommended for monitoring resistance with a mathematical approach and management of insecticide applications for the vector population.
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Affiliation(s)
- B A N Mendis
- Center for Biotechnology, Department of Zoology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - V Peiris
- Deakin University, 221 Burwood Hwy, Burwood, VIC, 3125, Australia
- Center for Optimization and Decision Science, Curtin University, Kent Street, Bentley, WA, 6102, Australia
| | - W A K Harshani
- Center for Biotechnology, Department of Zoology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - H S D Fernando
- Center for Biotechnology, Department of Zoology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - B G D N K de Silva
- Center for Biotechnology, Department of Zoology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka.
- Genetics and Molecular Biology Unit, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka.
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Ould Lemrabott MA, Briolant S, Gomez N, Basco L, Ould Mohamed Salem Boukhary A. First report of kdr mutations in the voltage-gated sodium channel gene in the arbovirus vector, Aedes aegypti, from Nouakchott, Mauritania. Parasit Vectors 2023; 16:464. [PMID: 38115092 PMCID: PMC10731742 DOI: 10.1186/s13071-023-06066-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 11/20/2023] [Indexed: 12/21/2023] Open
Abstract
BACKGROUND Since 2014, dengue epidemics have occurred almost annually in Nouakchott, the capital city of Mauritania, coinciding with the recent establishment of Aedes aegypti, the primary vector of dengue, in the city. Anopheles arabiensis, the primary vector of malaria, is also abundant not only in Nouakchott but also in most areas of the country. Resistance to insecticides has been studied in An. arabiensis but not in Ae. aegypti in Mauritania. The objective of the present study was to establish the baseline data on the frequencies of knockdown resistance (kdr) mutations in the voltage-gated sodium channel (vgsc) gene in Ae. aegypti collected in Nouakchott to improve vector control. METHODS Resting Ae. aegypti mosquitoes were collected in 2017 and 2018 in Teyarett and Dar Naim districts in Nouakchott using a battery-powered aspirator. Polymerase chain reaction (PCR) and DNA sequencing were performed to detect the presence of five kdr mutations known to be associated with pyrethroid resistance: L982W, S989P, I1011M/G, V1016G/I, and F1534C. RESULTS A total of 100 female Ae. aegypti mosquitoes were identified among collected resting culicid fauna, of which 60% (60/100) were unfed, 12% (12/100) freshly blood-fed, and 28% (28/100) gravid. Among the mutations investigated in this study, 989P, 1016G, and 1534C were found to be widespread, with the frequencies of 0.43, 0.44, and 0.55, respectively. Mutations were not found in codons 982 and 1011. No other mutations were detected within the fragments analyzed in this study. Genotype distribution did not deviate from Hardy-Weinberg equilibrium. The most frequent co-occurring point mutation patterns among Ae. aegypti mosquitoes were the heterozygous individuals 989SP/1016VG/1534FC detected in 45.1% of mosquitoes. In addition, homozygous mutant 1534CC co-occurred simultaneously with homozygous wild type 989SS and 1016VV in 30.5% of mosquito specimens. Inversely, homozygous wild-type 1534FF co-occurred simultaneously with homozygous mutant 989PP and 1016GG in 19.5% of the mosquitoes. CONCLUSIONS To our knowledge, this is the first study reporting the presence of three point mutations in the vgsc gene of Ae. aegypti in Mauritania. The findings of the present study are alarming because they predict a high level of resistance to pyrethroid insecticides which are commonly used in vector control in the country. Therefore, further studies are urgently needed, in particular phenotypic characterization of insecticide resistance using the standardized test.
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Affiliation(s)
| | - Sébastien Briolant
- Aix Marseille Université, IRD, AP-HM, SSA, VITROME, Marseille, France.
- IHU-Méditerranée Infection, Marseille, France.
- Unité de Parasitologie Entomologie, Département de Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées (IRBA), Marseille, France.
| | - Nicolas Gomez
- Aix Marseille Université, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
- Unité de Parasitologie Entomologie, Département de Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées (IRBA), Marseille, France
| | - Leonardo Basco
- Aix Marseille Université, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
| | - Ali Ould Mohamed Salem Boukhary
- Université de Nouakchott, UR-GEMI, Nouveau Campus Universitaire, BP 5026, Nouakchott, Mauritania.
- Aix Marseille Université, IRD, AP-HM, SSA, VITROME, Marseille, France.
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Prasad P, Lata S, Kumar D, Gupta SK, Saxena R, Arya DK, Singh H. Susceptibility status of Aedes aegypti (Diptera: Culicidae) against insecticides of public health use in Delhi and NCR region, India. J Vector Borne Dis 2023; 60:300-306. [PMID: 37843241 DOI: 10.4103/0972-9062.374044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023] Open
Abstract
BACKGROUND & OBJECTIVES Aedes (Stegomyia) aegypti is a primary vector responsible for the transmission of various arboviral diseases in India. Without an effective drug or vaccine against these diseases, chemical insecticide-based vector control supplemented with source reduction remains the best option for their effective management. The development of insecticide resistance due to the continuous use of insecticides might affect the control operations. METHODS Adults and larvae of Aedes aegypti were collected from different localities in Delhi. Larvae were exposed to discriminating (0.02mg/l) and application (1mg/l) doses of temephos. WHO tube assay was conducted for F1 adults using impregnated insecticide papers of dichlorodiphenyltrichloroethane (DDT), malathion, deltamethrin, permethrin, cyfluthrin, and lambda-cyhalothrin. RESULTS Larvae of Ae. aegypti were found resistant (76.0%) to the discriminating dose of temephos, whereas suscep-tible (100.0%) to the application dose of the temephos. Adult Aedes (Fl) mosquitoes were resistant to DDT (23.7%), malathion (90.5%), deltamethrin (76.0%), permethrin (96.2 %) cyfluthrin (85.5%), and lambda-cyhalothrin (94.0%). INTERPRETATION & CONCLUSION Indoor residual spray is not used in Delhi for vector control. Resistance in Aedes might be due to pesticide usage for agricultural activities in peripheral regions of Delhi. There is a need to investigate more on the insecticide resistance mechanisms for indirect resistance development. Understanding the insecticide susceptibility status of urban vectors is critical for planning effective control strategies.
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Affiliation(s)
- Pooja Prasad
- ICMR-National Institute of Malaria Research, New Delhi; Department of Zoology, DSB Campus, Kumaun University, Nainital, Uttarakhand, India
| | - Suman Lata
- ICMR-National Institute of Malaria Research, New Delhi, India
| | - Dinesh Kumar
- ICMR-National Institute of Malaria Research, New Delhi, India
| | | | - Rekha Saxena
- ICMR-National Institute of Malaria Research, New Delhi, India
| | - Deepak Kumar Arya
- Department of Zoology, DSB Campus, Kumaun University, Nainital, Uttarakhand, India
| | - Himmat Singh
- ICMR-National Institute of Malaria Research, New Delhi, India
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Tanzila G, Rasheed SB, Khan NH, Kausar A, Jahan F, Wahid S. INSECTICIDE SUSCEPTIBILITY AND DETECTION OF kdr-GENE MUTATIONS IN AEDES AEGYPTI OF PESHAWAR, PAKISTAN. Acta Trop 2023; 242:106919. [PMID: 37028585 DOI: 10.1016/j.actatropica.2023.106919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 04/02/2023] [Accepted: 04/04/2023] [Indexed: 04/08/2023]
Abstract
Dengue is a common disease in Peshawar, Pakistan whose primary vector is Aedes aegypti mosquito. Due to absence of vaccines and proper drugs for dengue, vector control is a necessary tool. Insecticide resistance in vectors is a threat to the control of dengue vector. This study presents the susceptibility status of Ae. aegypti to eight insecticides in district Peshawar and screen the mutations in knock down resistant gene (kdr). Ae. aegypti were found highly resistant to DDT and Deltamethrin while highly susceptible to Cyfluthrin and Bendiocarb. DNA sequencing of two domains (II and III) of kdr-gene have detected four SNPs in domain IIS6 at positions S989P and V1016G and two mutations at position T1520I and F1534C in domain IIIS6. Results showed a low frequency i.e. 0.19 and 0.12 for S989P and V1016G, moderate for T1520I (0.42) and high frequency for F1534C (0.86). Mutational combinations showed that the predominant combination was SSVVTICC (43%) in which T1520I was heterozygous and F1534C was homozygous mutant. This study will be helpful in designing vector control strategies for the control of dengue in the studied area and will provide first knowledge about Kdr gene mutations that confer resistance in this species.
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Affiliation(s)
- Gule Tanzila
- Jinnah College for Women, University of Peshawar, Peshawar 25000, Pakistan
| | | | - Nazma Habib Khan
- Department of Zoology, University of Peshawar, Peshawar 25000, Pakistan
| | - Aisha Kausar
- Department of Zoology, University of Peshawar, Peshawar 25000, Pakistan
| | - Fatima Jahan
- Department of Zoology, Shaheed Benazir Bhutto Women University, Peshawar 25000, Pakistan
| | - Sobia Wahid
- Department of Zoology, University of Peshawar, Peshawar 25000, Pakistan.
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Marcombe S, Shimell K, Savage R, Howlett E, Luangamath P, Nilaxay S, Vungkyly V, Baby A, King M, Clarke J, Jeffries C, Jojo J, Lacey E, Bhatty F, Mabika D, Dela Cruz A, Fisher C, Mbadu M, Despiniadis I, Brey PT, Thammavong P, Jones AK. Detection of pyrethroid resistance mutations and intron variants in the voltage-gated sodium channel of Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus mosquitoes from Lao People's Democratic Republic. MEDICAL AND VETERINARY ENTOMOLOGY 2022; 36:424-434. [PMID: 35593512 PMCID: PMC9790263 DOI: 10.1111/mve.12580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 05/03/2022] [Indexed: 06/01/2023]
Abstract
In Lao People's Democratic Republic, Aedes aegypti (Linnaeus 1762) and Aedes albopictus (Skuse 1894) mosquitoes (Diptera: Culicidae) are vectors of arboviral diseases such as dengue. As the treatment for these diseases is limited, control of the vectors with the use of pyrethroid insecticides is still essential. However, mutations in the voltage-gated sodium channel (vgsc) gene giving rise to pyrethroid resistance are threatening vector control programs. Here, we analysed both Ae. aegypti and Ae. albopictus mosquitoes, which were collected in different districts of Laos (Kaysone Phomvihane, Vangvieng, Saysettha and Xaythany), for vgsc mutations commonly found throughout Asia (S989P, V1016G and F1534C). Sequences of the vgsc gene showed that the F1534C mutation was prevalent in both Aedes species. S989P and V1016G mutations were detected in Ae. aegypti from each site and were always found together. In addition, the mutation T1520I was seen in Ae. albopictus mosquitoes from Saysettha district as well as in all Ae. aegypti samples. Thus, mutations in the vgsc gene of Ae. aegypti are prevalent in the four districts studied indicating growing insecticide resistance throughout Laos. Constant monitoring programmes and alternative strategies for controlling Aedes should be utilized in order to prolong the effectiveness of pyrethroids thereby maximizing vector control.
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Affiliation(s)
- Sebastien Marcombe
- Institut Pasteur du LaosMinistry of HealthVientianeLao People's Democratic Republic
| | - Katherine Shimell
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Rachel Savage
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Edward Howlett
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | | | - Somphat Nilaxay
- Institut Pasteur du LaosMinistry of HealthVientianeLao People's Democratic Republic
| | - Vacky Vungkyly
- Institut Pasteur du LaosMinistry of HealthVientianeLao People's Democratic Republic
| | - Anne Baby
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Mathew King
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Josie Clarke
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Chloe Jeffries
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Josna Jojo
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Emily Lacey
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Farris Bhatty
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Dadirayi Mabika
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Andrea Dela Cruz
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Cerys Fisher
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Milca Mbadu
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Iasonas Despiniadis
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
| | - Paul T. Brey
- Institut Pasteur du LaosMinistry of HealthVientianeLao People's Democratic Republic
| | - Phoutmany Thammavong
- Institut Pasteur du LaosMinistry of HealthVientianeLao People's Democratic Republic
| | - Andrew K. Jones
- Department of Biological and Medical SciencesOxford Brookes University, HeadingtonOxfordUK
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Updating the Insecticide Resistance Status of Aedes aegypti and Aedes albopictus in Asia: A Systematic Review and Meta-Analysis. Trop Med Infect Dis 2022; 7:tropicalmed7100306. [PMID: 36288047 PMCID: PMC9607256 DOI: 10.3390/tropicalmed7100306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/21/2022] [Accepted: 10/13/2022] [Indexed: 11/24/2022] Open
Abstract
Background: Aedes aegypti and Aedes albopictus are two important vectors of several important arboviruses, including the dengue, chikungunya, and Zika viruses. Insecticide application is an important approach to reduce vector abundance during Aedes spp.-borne outbreaks in the absence of effective vaccines and treatments. However, insecticide overuse can result in the development of resistance, and careful monitoring of resistance markers is required. Methods: This meta-analysis and systematic review explored the spatial and temporal patterns of insecticide resistance in Asia from 2000 to 2021. PubMed, Scopus, EbscoHost, and Embase were used to enhance the search capability. The random-effects model was applied for the 94 studies that met our inclusion criteria for qualitative synthesis and meta-analysis. Results: Four major insecticides were studied (malathion, dichlorodiphenyltrichloroethane, permethrin, and deltamethrin). Dichlorodiphenyltrichloroethane resistance rates were high in both Ae. aegypti and Ae. albopictus (68% and 64%, respectively). Conversely, malathion resistance was less prevalent in Ae. aegypti (3%), and deltamethrin resistance was less common in Ae. albopictus (2%). Ae. aegypti displayed consistently high resistance rates (35%) throughout the study period, whereas the rate of insecticide resistance in Ae. albopictus increased from 5% to 12%. The rates of the major kdr mutations F1534C, V1016G, and S989P were 29%, 26%, and 22%, respectively. Conclusions: Insecticide resistance in both Ae. aegypti and Ae. albopictus is widespread in Asia, although the rates vary by country. Continuous monitoring of the resistance markers and modification of the control strategies will be important for preventing unexpected outbreaks. This systematic review and meta-analysis provided up-to-date information on insecticide resistance in dengue-endemic countries in Asia.
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Abstract
Commemorating the 2021 ASEAN Dengue Day and advocacy for World Dengue Day, the International Society for Neglected Tropical Diseases (ISNTD) and Asian Dengue Voice and Action (ADVA) Group jointly hosted the ISNTD-ADVA World Dengue Day Forum–Cross Sector Synergies in June 2021. The forum aimed to achieve international and multisectoral coordination to consolidate global dengue control and prevention efforts, share best practices and resources, and improve global preparedness. The forum featured experts around the world who shared their insight, research experience, and strategies to tackle the growing threat of dengue. Over 2,000 healthcare care professionals, researchers, epidemiologists, and policy makers from 59 countries attended the forum, highlighting the urgency for integrated, multisectoral collaboration between health, environment, education, and policy to continue the march against dengue. Sustained vector control, environmental management, surveillance improved case management, continuous vaccine advocacy and research, capacity building, political commitment, and community engagement are crucial components of dengue control. A coordinated strategy based on science, transparency, timely and credible communication, and understanding of human behavior is needed to overcome vaccine hesitancy, a major health risk further magnified by the COVID-19 pandemic. The forum announced a strong call to action to establish World Dengue Day to improve global awareness, share best practices, and prioritize preparedness in the fight against dengue. The growing threat of dengue poses a significant public health burden endangering the well-being and socioeconomic development of many countries across the world. The International Society for Neglected Tropical Diseases (ISNTD) and Asian Dengue Voice and Action (ADVA) group brought together the collaborative efforts of healthcare care professionals, researchers, epidemiologists, environmentalists, and policy makers to coordinate international dengue control strategy. A strong call to action to establish a World Dengue Day was announced to improve global awareness, share best practices, and prioritize preparedness in the fight against dengue. The World Dengue Day highlighted the need for all governments, healthcare professionals, civil societies, public and private sectors, schools and universities, and citizens in dengue-endemic countries to form a strong coalition to encourage and accelerate a collective dengue control response.
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Affiliation(s)
- Nattachai Srisawat
- Tropical Medicine Cluster, Chulalongkorn University, Excellence Center for Critical Care Nephrology, King Chulalongkorn Memorial Hospital, and Center of Excellence in Critical Care Nephrology, Chulalongkorn University, Bangkok, Thailand
- * E-mail:
| | - Usa Thisyakorn
- Tropical Medicine Cluster, Chulalongkorn University and Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Zulkifli Ismail
- Department of Pediatrics, KPJ Selangor Specialist Hospital, Selangor, Malaysia
| | - Kamran Rafiq
- International Society for Neglected Tropical Diseases, London, United Kingdom
| | - Duane J. Gubler
- Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
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Ranathunge T, Harishchandra J, Maiga H, Bouyer J, Gunawardena YINS, Hapugoda M. Development of the Sterile Insect Technique to control the dengue vector Aedes aegypti (Linnaeus) in Sri Lanka. PLoS One 2022; 17:e0265244. [PMID: 35377897 PMCID: PMC8979456 DOI: 10.1371/journal.pone.0265244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 02/24/2022] [Indexed: 11/17/2022] Open
Abstract
Background The Sterile Insect Technique (SIT) is presently being tested to control dengue in several countries. SIT aims to cause the decline of the target insect population through the release of a sufficient number of sterilized male insects. This induces sterility in the female population, as females that mate with sterilized males produce no offspring. Male insects are sterilized through the use of ionizing irradiation. This study aimed to evaluate variable parameters that may affect irradiation in mosquito pupae. Methods An Ae. aegypti colony was maintained under standard laboratory conditions. Male and female Ae. aegypti pupae were separated using a Fay and Morlan glass sorter and exposed to different doses of gamma radiation (40, 50, 60, 70 and 80 Gy) using a Co60 source. The effects of radiation on survival, flight ability and the reproductive capacity of Ae. aegypti were evaluated under laboratory conditions. In addition, mating competitiveness was evaluated for irradiated male Ae. aegypti mosquitoes to be used for future SIT programmes in Sri Lanka. Results Survival of irradiated pupae was reduced by irradiation in a dose-dependent manner but it was invariably greater than 90% in control, 40, 50, 60, 70 Gy in both male and female Ae. aegypti. Irradiation didn’t show any significant adverse effects on flight ability of male and female mosquitoes, which consistently exceeded 90%. A similar number of eggs per female was observed between the non-irradiated groups and the irradiated groups for both irradiated males and females. Egg hatch rates were significantly lower when an irradiation dose above 50 Gy was used as compared to 40 Gy in both males and females. Irradiation at higher doses significantly reduced male and female survival when compared to the non-irradiated Ae. aegypti mosquitoes. Competitiveness index (C) scores of sterile and non-sterile males compared with non-irradiated male mosquitoes under laboratory and semi-field conditions were 0.56 and 0.51 respectively at 50 Gy. Signification Based on the results obtained from the current study, a 50 Gy dose was selected as the optimal radiation dose for the production of sterile Ae. aegypti males for future SIT-based dengue control programmes aiming at the suppression of Ae. aegypti populations in Sri Lanka.
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Affiliation(s)
- Tharaka Ranathunge
- Molecular Medicine Unit, Faculty of Medicine University of Kelaniya, Colombo, Sri Lanka.,Department of Biomedical Sciences, Faculty of Health Sciences, CINEC Campus, Malabe, Sri Lanka
| | - Jeevanie Harishchandra
- Anti-Malaria Campaign (AMC) Public Health Complex, Ministry of Health, Colombo, Sri Lanka
| | - Hamidou Maiga
- Insect Pest Control Subprogramme, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna, Austria
| | - Jeremy Bouyer
- Insect Pest Control Subprogramme, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna, Austria
| | | | - Menaka Hapugoda
- Molecular Medicine Unit, Faculty of Medicine University of Kelaniya, Colombo, Sri Lanka
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Boyer S, Maquart PO, Chhuoy K, Suor K, Chhum M, Heng K, Leng S, Fontenille D, Marcombe S. Monitoring insecticide resistance of adult and larval Aedes aegypti (Diptera: Culicidae) in Phnom Penh, Cambodia. Parasit Vectors 2022; 15:44. [PMID: 35101104 PMCID: PMC8805314 DOI: 10.1186/s13071-022-05156-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/08/2022] [Indexed: 01/01/2023] Open
Abstract
Background Dengue fever is a major public health concern in Cambodia, with thousands of cases every year in urban, suburban and rural areas of the country. The main vector of dengue fever in Cambodia is Aedes aegypti. The organophosphate larvicide temephos and adulticides belonging to the pyrethroid family have been widely used for decades by public health authorities to fight dengue vectors, but resistance of Ae. aegypti to these insecticides has been previously described for Cambodia. Methods In order to adapt the vector control strategy presently used in Cambodia, we tested 14 adulticides belonging to the carbamate, organochlorine, organophosphate, and pyrethroid insecticide families and three larvicides [temephos, spinosad and Bacillus thuringiensis ser. israelensis (Bti)] belonging to three different insecticide families (organophosphates, spinosyns and entomopathogenic bacteria). The standard procedures used here to test the adults and larvae of an Ae. aegypti population from Phnom Penh followed World Health Organization guidelines. Results For adults, high mortality rates were observed with carbamate, organophosphate and organochlorine (with the exception of dichlorodiphenyltrichloroethane) insecticides (i.e. between 87.6 and 100%), while low mortality rates were observed with all of the tested pyrethroid insecticides (i.e. between 1 and 35%). For larvae, no resistance against Bti was detected [resistance ratio (RR90 < 1.6)], but moderate resistance was observed for temephos and spinosad (RR90 < 5.6). Conclusions The results of this study indicate that (i) Bti should be considered a serious alternative to temephos for the control of Ae. aegypti larvae; and (ii) the carbamate adulticides propoxur and bendiocarb should be employed instead of the widely used pyrethroid insecticides for the control of adult Ae. aegypti on land under mosaic farming and crop rotation in Cambodia, as the insects were found to be resistant to the latter types of insecticide. Research focusing on insecticide resistance and innovative and effective vector control strategies should be undertaken as a public health priority in Cambodia. Graphical abstract ![]()
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12
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Gan SJ, Leong YQ, Bin Barhanuddin MFH, Wong ST, Wong SF, Mak JW, Ahmad RB. Dengue fever and insecticide resistance in Aedes mosquitoes in Southeast Asia: a review. Parasit Vectors 2021; 14:315. [PMID: 34112220 PMCID: PMC8194039 DOI: 10.1186/s13071-021-04785-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 05/11/2021] [Indexed: 12/26/2022] Open
Abstract
Dengue fever is the most important mosquito-borne viral disease in Southeast Asia. Insecticides remain the most effective vector control approach for Aedes mosquitoes. Four main classes of insecticides are widely used for mosquito control: organochlorines, organophosphates, pyrethroids and carbamates. Here, we review the distribution of dengue fever from 2000 to 2020 and its associated mortality in Southeast Asian countries, and we gather evidence on the trend of insecticide resistance and its distribution in these countries since 2000, summarising the mechanisms involved. The prevalence of resistance to these insecticides is increasing in Southeast Asia, and the mechanisms of resistance are reported to be associated with target site mutations, metabolic detoxification, reduced penetration of insecticides via the mosquito cuticle and behavioural changes of mosquitoes. Continuous monitoring of the status of resistance and searching for alternative control measures will be critical for minimising any unpredicted outbreaks and improving public health. This review also provides improved insights into the specific use of insecticides for effective control of mosquitoes in these dengue endemic countries. ![]()
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Affiliation(s)
- Soon Jian Gan
- International Medical University, 57000, Kuala Lumpur, Malaysia
| | - Yong Qi Leong
- International Medical University, 57000, Kuala Lumpur, Malaysia.,Monash University Malaysia, 47500, Subang Jaya, Selangor, Malaysia
| | | | - Siew Tung Wong
- International Medical University, 57000, Kuala Lumpur, Malaysia
| | - Shew Fung Wong
- International Medical University, 57000, Kuala Lumpur, Malaysia. .,Institute for Research, Development and Innovation (IRDI), International Medical University, 57000, Kuala Lumpur, Malaysia.
| | - Joon Wah Mak
- International Medical University, 57000, Kuala Lumpur, Malaysia.,Institute for Research, Development and Innovation (IRDI), International Medical University, 57000, Kuala Lumpur, Malaysia
| | - Rohani Binti Ahmad
- Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
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Voltage-Gated Sodium Channel ( Vgsc) Mutation-Based Pyrethroid Resistance in Aedes aegypti Populations of Three Endemic Dengue Risk Areas of Sri Lanka. BIOMED RESEARCH INTERNATIONAL 2021; 2021:8874092. [PMID: 34124263 PMCID: PMC8166465 DOI: 10.1155/2021/8874092] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 03/24/2021] [Accepted: 05/16/2021] [Indexed: 11/17/2022]
Abstract
Background Pyrethroid insecticides are widely used in many countries for chemical-based control of Ae. aegypti. Regardless of their efficacy, the constant use of insecticides has induced insecticide resistance mechanisms, such as knockdown resistance (kdr) in mosquitoes. Sri Lankan Vector Controlling Entities (VCE) have been using a variety of pyrethroid insecticides as the primary approach for dengue control. However, development of any resistance among the Aedes mosquitoes has been limitedly studied in the country. Therefore, the current study was conducted to evaluate the prevalence of F1534C, V1016G, and S989P mutations among Ae. aegypti mosquito populations in three dengue endemic high-risk regions of Sri Lanka. Methodology. Immature (both pupae and larvae) stages of Ae. aegypti mosquitoes were collected from Colombo, Gampaha, and Kandy districts of Sri Lanka from February 2018 to December 2019. Polymerase Chain Reaction- (PCR-) based assay for molecular genotyping of mutations was performed to identify the prevalence of kdr mutations in collected Ae. aegypti populations, separately. The frequencies of the resistant and susceptible kdr alleles were determined by using the Hardy–Weinberg equilibrium. Results The Ae. aegypti populations from Colombo, Gampaha, and Kandy districts showed 46%, 42%, and 22% of F1534C mutation allele frequencies, along with 15%, 12%, and 6% of V1016G mutation allele frequencies, respectively. The mutation allele frequencies of S989 in Colombo, Gampaha, and Kandy districts were 9.5%, 8.5%, and 4.5%, respectively. The wild-type (PP) genotype remained predominant within all the three districts, whereas the homogenous (QQ) mutation genotype occurred only in minority. The abundance of Q allele frequency in Ae. aegypti mosquitoes was relatively higher for all the three mutations in Colombo. Conclusions The findings clearly indicate that long-term insecticide applications and multiple use of pyrethroids have led to the acquisition of kdr mutations, leading to the development of insecticide resistance among local Ae. aegypti populations, especially in the Colombo and Gampaha districts. Therefore, evaluation of the prevalence levels of these kdr mutations highlights the necessity for shifting towards novel vector control strategies.
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14
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Dalpadado R, Gunathilaka N, Amarasinghe D, Udayanaga L. A Challenge for a Unique Dengue Vector Control Programme: Assessment of the Spatial Variation of Insecticide Resistance Status amongst Aedes aegypti and Aedes albopictus Populations in Gampaha District, Sri Lanka. BIOMED RESEARCH INTERNATIONAL 2021; 2021:6619175. [PMID: 33884266 PMCID: PMC8041548 DOI: 10.1155/2021/6619175] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 03/11/2021] [Accepted: 03/24/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND To date, dengue is considered an important public health problem in Sri Lanka. Irrational use of insecticides without evidence-based applications has primed the development of resistance in mosquito vectors. METHOD The present study investigated the resistance status of Aedes aegypti and Aedes albopictus to commonly used insecticides in three selected Medical Officer of Health (MOH) areas (i.e., Attanagalla, Dompe, and Negombo) in Gampaha District, Western Province of Sri Lanka. Entomological surveys were performed using ovitraps and larval collections. Larval bioassays were carried out to determine the LC50, LC90, and LC95 and susceptibility status for organophosphate temephos, whereas adult bioassays were performed to test the 0.03% deltamethrin and 0.8% malathion susceptibility. RESULTS The study revealed that the temephos concentrations required to control Ae. aegypti (13.7-17.7 times) and Ae. albopictus (4.6-7.6 times) are higher than the diagnostic concentration (0.012 mg/L) proposed by the World Health Organization. The highest resistance levels were observed for both Ae. aegypti (14 ± 1.87) and Ae. albopictus (36 ± 1.87) collected from the Negombo MOH area. Therefore, the WHO recommended diagnostic concentration is no longer effective in controlling Ae. aegypti and Ae. albopictus larvae in these areas. Both the dengue vectors have evolved a high level of insecticide resistance to malathion and deltamethrin in the Gampaha District except Ae. albopictus mosquitoes in rural areas. Further, vectors in rural areas are indicated susceptible (>98%) to pyrethroids and emergence of resistance (<97%) for organophosphate insecticides. CONCLUSION The results of this study warrant the vector management authorities on the proper application of insecticides and rational use in vector control. The susceptibility status of vector mosquitoes should be continuously monitored especially in dengue-endemic areas parallel to the routine surveillance programme. Further molecular studies are strongly recommended to determine the Knockdown Resistance (kdr) mutations among Aedes populations.
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Affiliation(s)
- Rasika Dalpadado
- Regional Director of Health Services Office, Gampaha District, Gampaha, Sri Lanka
| | - Nayana Gunathilaka
- Department of Parasitology, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka
| | - Deepika Amarasinghe
- Department of Zoology and Environmental Management, Faculty of Science, University of Kelaniya, Dalugama, Sri Lanka
| | - Lahiru Udayanaga
- Department of Biosystems Engineering, Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makadura, Sri Lanka
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15
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Insecticide resistance and underlying targets-site and metabolic mechanisms in Aedes aegypti and Aedes albopictus from Lahore, Pakistan. Sci Rep 2021; 11:4555. [PMID: 33633183 PMCID: PMC7907206 DOI: 10.1038/s41598-021-83465-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 01/18/2021] [Indexed: 01/31/2023] Open
Abstract
Insecticide resistant Aedes populations have recently been reported in Pakistan, imposing a threat to their control. We aimed to evaluate the susceptibility of Aedes aegypti and Aedes albopictus populations from Lahore to WHO-recommended insecticides and to investigate metabolic and target-site resistance mechanisms. For this purpose, we first carried out bioassays with the larvicides temephos and pyriproxyfen, and the adulticides malathion, permethrin, deltamethrin, alpha-cypermethrin, and etofenprox. We looked for Knockdown resistance mutations (kdr) by qPCR, High-Resolution Melt (HRM), and sequencing. In order to explore the role of detoxifying enzymes in resistance, we carried out synergist bioassay with both species and then checked the expression of CYP9M6, CYP9J10, CYP9J28, CYP6BB2, CCAe3a, and SAP2 genes in Ae. aegypti. Both species were susceptible to organophosphates and the insect growth regulator, however resistant to all pyrethroids. We are reporting the kdr haplotypes 1520Ile + 1534Cys and T1520 + 1534Cys in high frequencies in Ae. aegypti while Ae. albopictus only exhibited the alteration L882M. PBO increased the sensitivity to permethrin in Ae. aegypti, suggesting the participation of P450 genes in conferring resistance, and indeed, CYP928 was highly expressed. We presume that dengue vectors in Lahore city are resistant to pyrethroids, probably due to multiple mechanisms, such as kdr mutations and P450 overexpression.
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16
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Rigby LM, Johnson BJ, Rašić G, Peatey CL, Hugo LE, Beebe NW, Hartel GF, Devine GJ. The presence of knockdown resistance mutations reduces male mating competitiveness in the major arbovirus vector, Aedes aegypti. PLoS Negl Trop Dis 2021; 15:e0009121. [PMID: 33544711 PMCID: PMC7891746 DOI: 10.1371/journal.pntd.0009121] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 02/18/2021] [Accepted: 01/10/2021] [Indexed: 01/08/2023] Open
Abstract
Background The development of insecticide resistance in mosquitoes can have pleiotropic effects on key behaviours such as mating competition and host-location. Documenting these effects is crucial for understanding the dynamics and costs of insecticide resistance and may give researchers an evidence base for promoting vector control programs that aim to restore or conserve insecticide susceptibility. Methods and findings We evaluated changes in behaviour in a backcrossed strain of Aedes aegypti, homozygous for two knockdown resistance (kdr) mutations (V1016G and S989P) isolated in an otherwise fully susceptible genetic background. We compared biting activity, host location behaviours, wing beat frequency (WBF) and mating competition between the backcrossed strain, and the fully susceptible and resistant parental strains from which it was derived. The presence of the homozygous kdr mutations did not have significant effects on blood avidity, the time to locate a host, or WBF in females. There was, however, a significant reduction in mean WBF in males and a significant reduction in estimated male mating success (17.3%), associated with the isolated kdr genotype. Conclusions Our results demonstrate a cost of insecticide resistance associated with an isolated kdr genotype and manifest as a reduction in male mating success. While there was no recorded difference in WBF between the females of our strains, the significant reduction in male WBF recorded in our backcrossed strain might contribute to mate-recognition and mating disruption. These consequences of resistance evolution, especially when combined with other pleiotropic fitness costs that have been previously described, may encourage reversion to susceptibility in the absence of insecticide selection pressures. This offers justification for the implementation of insecticide resistance management strategies based on the rotation or alternation of different insecticide classes in space and time. The mosquito Aedes aegypti is the main vector of dengue, chikungunya, and Zika. Its control relies heavily on the use of insecticides but the rapid evolution of resistance to these chemicals compromises their efficacy. The conservation or restoration of insecticide susceptibility in Ae. aegypti populations is therefore of great importance. Insecticide susceptibility can be encouraged if the evolution of resistance is accompanied by fitness costs that favour susceptible mosquitoes in the absence of insecticides. This paper documents the first report of a reduction in mating success directly associated with an isolated mutation that confers insecticide resistance in Ae. aegypti. This change in behaviour appears related to alterations in male wing-beat frequency. Our results provide evidence of behavioural changes related to insecticide resistance in Ae. aegypti, suggesting a competitive advantage of susceptible individuals in the absence of insecticides in the field.
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Affiliation(s)
- Lisa M. Rigby
- Australian Defence Force Malaria and Infectious Disease Institute, Gallipoli Barracks, Enoggera, Australia
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, Australia
- School of Medicine, University of Queensland, Brisbane, Australia
- * E-mail:
| | - Brian J. Johnson
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, Australia
| | - Gordana Rašić
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, Australia
| | - Christopher L. Peatey
- Australian Defence Force Malaria and Infectious Disease Institute, Gallipoli Barracks, Enoggera, Australia
| | - Leon E. Hugo
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, Australia
| | - Nigel W. Beebe
- School of Biological Sciences, University of Queensland, Brisbane, Australia
- CSIRO, Brisbane, Australia
| | - Gunter F. Hartel
- Department of Statistics, QIMR Berghofer Medical Research Institute, Herston, Australia
| | - Gregor J. Devine
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, Australia
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Chandrasiri PKGK, Fernando SD, De Silva BGDNK. Insecticide resistance and molecular characterization of knockdown resistance (kdr) in Culex quinquefasciatus mosquitoes in Sri Lanka. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2020; 45:204-210. [PMID: 33207057 DOI: 10.1111/jvec.12391] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
Resistance to pyrethroids (PY) and organophosphate (OP) insecticides is widespread among populations of Culex quinquefasciatus, the major vector of lymphatic filariasis (LF). The present study was designed to detect the L1014F kdr (knockdown resistant) mutation among Cx. quinquefasciatus populations in the filarial belt of Sri Lanka. Mosquitoes were reared from field-caught larvae from seven localities where LF is endemic. Susceptibility status of Cx. quinquefasciatus to adulticides, 0.05% deltamethrin, 0.75% permethrin, 5% malathion, and the larvicide temephos was determined using the standard WHO susceptibility tests. A fragment of vgsc gene was amplified and sequenced to identify the responsible kdr mutations. The susceptibility test results revealed less than 90% mortalities for 0.05% deltamethrin, and 0.75% permethrin and temephos. For 5% malathion, all study sites except Maharagama revealed greater than 90% mortality. The L1014F kdr mutation was observed in all studied populations. Although the overall microfilaria rate is less than 1% in the country, there is a high risk of re-emergence of LF in Sri Lanka due to abundant Cx. quinquefasciatus mosquitoes, increased resistant status to currently used insecticides, imported LF cases, higher rates of microfilaria among neighboring countries, and the advancement of tourism.
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Affiliation(s)
| | - Sachini D Fernando
- Center for Biotechnology, Department of Zoology, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - B G D Nissanka K De Silva
- Center for Biotechnology, Department of Zoology, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
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Fernando HSD, Saavedra-Rodriguez K, Perera R, Black WC, De Silva BGDNK. Resistance to commonly used insecticides and underlying mechanisms of resistance in Aedes aegypti (L.) from Sri Lanka. Parasit Vectors 2020; 13:407. [PMID: 32778147 PMCID: PMC7418196 DOI: 10.1186/s13071-020-04284-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 08/03/2020] [Indexed: 11/28/2022] Open
Abstract
Background Drastic increases of dengue fever (DF) over the past few years have prompted studies on the development of resistance to insecticides in the mosquito vector, Aedes aegypti (Linnaeus). In Sri Lanka control of the vector population is essentially achieved using larvicides (temephos) and adulticides (principally pyrethroids). The present study investigates resistance to commonly used insecticides and underlying mechanisms of Ae. aegypti in selected sites in Sri Lanka. Methods In this study, susceptibility to three commonly used adulticides (malathion, permethrin and deltamethrin) and the larvicide temephos were tested for Ae. aegypti sampled from five localities in Sri Lanka using WHO dose diagnostics tests. In addition, we performed dose-response tests for permethrin to determine lethal concentrations (LCs) with CDC bottle bioassays. An assessment of the activity of metabolic detoxifying enzymes (multifunction oxidases (MFOs), glutathione S-transferases (GSTs) and esterases) and determination of frequency of the kdr mutations (F1534C, V1016G and S989P) were also carried out to ascertain the associated resistance mechanisms. Kdr genotype frequencies were compared with samples collected from the same sites in 2015 to determine the change of allele frequencies over the years. Results The present study revealed resistance in all Ae. aegypti populations studied, with low mortality percentages for both permethrin (10–89%) and deltamethrin (40–92%). Dose response tests revealed highest resistance ratios (RR) for permethrin and temephos from Colombo district whereas Puttalum district exhibited the lowest. High frequencies of the 1534C allele (0.052–0.802) were found in the study sites in 2017. Comparison with samples collected in 2015 revealed a substantial increase in this allele. The activity of MFOs and p-nitro phenyl-acetate esterase was significantly greater in most Sri Lankan populations in comparison to that of the New Orleans (NO) susceptible strain. In contrast, the activity of α-esterase and β-esterase was similar or lower than that in the NO strain. Conclusions Aedes aegypti from Sri Lanka is resistant to pyrethroid insecticides showing rapid selection for kdr mutations and varying metabolic mechanisms. Continued monitoring of vector populations is crucial to mitigate the development of resistance to commonly used insecticides and in turn, controlling the vector population.![]()
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Affiliation(s)
- H Sachini D Fernando
- Center for Biotechnology, Department of Zoology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - Karla Saavedra-Rodriguez
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Rushika Perera
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
| | - William C Black
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
| | - B G D Nissanka Kolitha De Silva
- Center for Biotechnology, Department of Zoology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka.
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Rigby LM, Rašić G, Peatey CL, Hugo LE, Beebe NW, Devine GJ. Identifying the fitness costs of a pyrethroid-resistant genotype in the major arboviral vector Aedes aegypti. Parasit Vectors 2020; 13:358. [PMID: 32690061 PMCID: PMC7372837 DOI: 10.1186/s13071-020-04238-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 07/15/2020] [Indexed: 11/18/2022] Open
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. ![]()
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Affiliation(s)
- Lisa M Rigby
- Australian Defence Force Malaria and Infectious Disease Institute, Gallipoli Barracks, Enoggera, QLD, 4051, Australia. .,Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, 4006, Australia. .,School of Biological Sciences, University of Queensland, Brisbane, Australia.
| | - Gordana Rašić
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, 4006, Australia
| | - Christopher L Peatey
- Australian Defence Force Malaria and Infectious Disease Institute, Gallipoli Barracks, Enoggera, QLD, 4051, Australia
| | - Leon E Hugo
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, 4006, Australia
| | - Nigel W Beebe
- School of Biological Sciences, University of Queensland, Brisbane, Australia.,CSIRO, Brisbane, QLD, Australia
| | - Gregor J Devine
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, 4006, Australia
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Villanueva-Segura K, Ponce-Garcia G, Lopez-Monroy B, Mora-Jasso E, Perales L, Gonzalez-Santillan FJ, Ontiveros-Zapata K, Davila-Barboza JA, Flores AE. Multiplex PCR for simultaneous genotyping of kdr mutations V410L, V1016I and F1534C in Aedes aegypti (L.). Parasit Vectors 2020; 13:325. [PMID: 32586378 PMCID: PMC7318494 DOI: 10.1186/s13071-020-04193-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 06/17/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Knockdown resistance (kdr) is the main mechanism that confers resistance to pyrethroids and DDT. This is a product of non-synonymous mutations in the voltage-gated sodium channel (vgsc) gene, and these mutations produce a change of a single amino acid which reduces the affinity of the target site for the insecticide molecule. In Mexico, V410L, V1016I and F1534C mutations are common in pyrethroid-resistant Aedes aegypti (L.) populations. METHODS A multiplex PCR was developed to detect the V410L, V1016I and F1534C mutations in Ae. aegypti. The validation of the technique was carried out by DNA sequencing using field populations previously characterized for the three mutations through allele-specific PCR (AS-PCR) and with different levels of genotypic frequencies. RESULTS The standardized protocol for multiplex end-point PCR was highly effective in detecting 15 genotypes considering the three mutations V410L, V1106I and F1534C, in 12 field populations of Ae. aegypti from Mexico. A complete concordance with AS-PCR and DNA sequencing was found for the simultaneous detection of the three kdr mutations. CONCLUSIONS Our diagnostic method is highly effective for the simultaneous detection of V410L, V1016I and F1534C, when they co-occur. This technique represents a viable alternative to complement and strengthen current monitoring and resistance management strategies against Ae. aegypti.
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Affiliation(s)
- Karina Villanueva-Segura
- Universidad Autonoma de Nuevo Leon (UANL), Av, Universidad s/n Cd. Universitaria, 66455, San Nicolas de los Garza, N.L., Mexico
| | - Gustavo Ponce-Garcia
- Universidad Autonoma de Nuevo Leon (UANL), Av, Universidad s/n Cd. Universitaria, 66455, San Nicolas de los Garza, N.L., Mexico
| | - Beatriz Lopez-Monroy
- Universidad Autonoma de Nuevo Leon (UANL), Av, Universidad s/n Cd. Universitaria, 66455, San Nicolas de los Garza, N.L., Mexico
| | - Esteban Mora-Jasso
- Universidad Autonoma de Nuevo Leon (UANL), Av, Universidad s/n Cd. Universitaria, 66455, San Nicolas de los Garza, N.L., Mexico
| | - Lucia Perales
- Universidad Autonoma de Nuevo Leon (UANL), Av, Universidad s/n Cd. Universitaria, 66455, San Nicolas de los Garza, N.L., Mexico
| | - Francisco J Gonzalez-Santillan
- Universidad Autonoma de Nuevo Leon (UANL), Av, Universidad s/n Cd. Universitaria, 66455, San Nicolas de los Garza, N.L., Mexico
| | - Kevin Ontiveros-Zapata
- Universidad Autonoma de Nuevo Leon (UANL), Av, Universidad s/n Cd. Universitaria, 66455, San Nicolas de los Garza, N.L., Mexico
| | - Jesus A Davila-Barboza
- Universidad Autonoma de Nuevo Leon (UANL), Av, Universidad s/n Cd. Universitaria, 66455, San Nicolas de los Garza, N.L., Mexico
| | - Adriana E Flores
- Universidad Autonoma de Nuevo Leon (UANL), Av, Universidad s/n Cd. Universitaria, 66455, San Nicolas de los Garza, N.L., Mexico.
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21
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Chen M, Du Y, Nomura Y, Zhorov BS, Dong K. Chronology of sodium channel mutations associated with pyrethroid resistance in Aedes aegypti. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2020; 104:e21686. [PMID: 32378259 PMCID: PMC8060125 DOI: 10.1002/arch.21686] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 05/11/2023]
Abstract
Aedes aegypti is the primary mosquito vector of dengue, yellow fever, Zika and chikungunya. Current strategies to control Ae. aegypti rely heavily on insecticide interventions. Pyrethroids are a major class of insecticides used for mosquito control because of their fast acting, highly insecticidal activities and low mammalian toxicity. However, Ae. aegypti populations around the world have begun to develop resistance to pyrethroids. So far, more than a dozen mutations in the sodium channel gene have been reported to be associated with pyrethroid resistance in Ae. aegypti. Co-occurrence of resistance-associated mutations is common in pyrethroid-resistant Ae. aegypti populations. As global use of pyrethroids in mosquito control continues, new pyrethroid-resistant mutations keep emerging. In this microreview, we compile pyrethroid resistance-associated mutations in Ae. aegypti in a chronological order, as they were reported, and summarize findings from functional evaluation of these mutations in an in vitro sodium channel expression system. We hope that the information will be useful for tracing possible evolution of pyrethroid resistance in this important human disease vector, in addition to the development of methods for global monitoring and management of pyrethroid resistance in Ae. aegypti.
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Affiliation(s)
- Mengli Chen
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of life sciences, China Jiliang University, Hangzhou, China
| | - Yuzhe Du
- USDA-ARS, Biological Control of Pest Research Unit, 59 Lee Road, Stoneville, MS 38776, USA
| | - Yoshiko Nomura
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, MI 48824, USA
| | - Boris S. Zhorov
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, 194223, Russia
| | - Ke Dong
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, MI 48824, USA
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22
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Contreras-Perera Y, Ponce-Garcia G, Villanueva-Segura K, Lopez-Monroy B, Rodríguez-Sanchez IP, Lenhart A, Manrique-Saide P, Flores AE. Impact of deltamethrin selection on kdr mutations and insecticide detoxifying enzymes in Aedes aegypti from Mexico. Parasit Vectors 2020; 13:224. [PMID: 32375862 PMCID: PMC7201803 DOI: 10.1186/s13071-020-04093-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/24/2020] [Indexed: 12/02/2022] Open
Abstract
Background Insecticide resistance is a serious problem for vector control programmes worldwide. Resistance is commonly attributed to mutations at the insecticide’s target site or increased activity of detoxification enzymes. Methods We determined the knockdown concentration (KC50) and lethal concentration (LC50) of deltamethrin in six natural populations of adult Aedes aegypti from southeastern Mexico. These populations were then selected over five generations using the LC50 from the preceding generation that underwent selection, and the heritability of deltamethrin resistance was quantified. For each generation, we also determined the frequency of the kdr alleles L410, I1016 and C1534, and the levels of activity of three enzyme families (α- and β-esterases, mixed-function oxidases and glutathione S-transferases (GST)) associated with insecticide detoxification. Results There was an increase in KC50 and LC50 values in the subsequent generations of selection with deltamethrin (FS5vs FS0). According to the resistance ratios (RRs), we detected increases in LC50 ranging from 1.5 to 5.6 times the values of the parental generation and in KC50 ranging from 1.3–3.8 times the values of the parental generation. Triple homozygous mutant individuals (tri-locus, LL/II/CC) were present in the parental generations and increased in frequency after selection. The frequency of L410 increased from 1.18-fold to 2.63-fold after selection with deltamethrin (FS5vs FS0) in the populations analyzed; for I1016 an increase between 1.19-fold to 2.79-fold was observed, and C1534 was fixed in all populations after deltamethrin selection. Enzymatic activity varied significantly over the generations of selection. However, only α- esterase activity remained elevated in multiple populations after five generations of deltamethrin selection. We observed an increase in the mean activity levels of GSTs in two of the six populations analyzed. Conclusions The high levels of resistance and their association with high frequencies of kdr mutations (V410L, V1016I and F1534C) obtained through artificial selection, suggest an important role of these mutations in conferring resistance to deltamethrin. We highlight the need to implement strategies that involve the monitoring of kdr frequencies in insecticide resistance monitoring and management programmes.![]()
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Affiliation(s)
- Yamili Contreras-Perera
- Facultad de Ciencias Biologicas, Universidad Autonoma de Nuevo Leon, Cd, Universitaria, San Nicolas de los Garza, N.L., CP. 66455, Mexico
| | - Gustavo Ponce-Garcia
- Facultad de Ciencias Biologicas, Universidad Autonoma de Nuevo Leon, Cd, Universitaria, San Nicolas de los Garza, N.L., CP. 66455, Mexico
| | - Karina Villanueva-Segura
- Facultad de Ciencias Biologicas, Universidad Autonoma de Nuevo Leon, Cd, Universitaria, San Nicolas de los Garza, N.L., CP. 66455, Mexico
| | - Beatriz Lopez-Monroy
- Facultad de Ciencias Biologicas, Universidad Autonoma de Nuevo Leon, Cd, Universitaria, San Nicolas de los Garza, N.L., CP. 66455, Mexico
| | - Iram P Rodríguez-Sanchez
- Facultad de Ciencias Biologicas, Universidad Autonoma de Nuevo Leon, Cd, Universitaria, San Nicolas de los Garza, N.L., CP. 66455, Mexico
| | - Audrey Lenhart
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Pablo Manrique-Saide
- Unidad Colaborativa para Bioensayos Entomologicos, Universidad Autonoma de Yucatan, Campus de Ciencias Biologicas y Agropecuarias, Merida, Yucatan, Mexico
| | - Adriana E Flores
- Facultad de Ciencias Biologicas, Universidad Autonoma de Nuevo Leon, Cd, Universitaria, San Nicolas de los Garza, N.L., CP. 66455, Mexico.
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Kawada H, Futami K, Higa Y, Rai G, Suzuki T, Rai SK. Distribution and pyrethroid resistance status of Aedes aegypti and Aedes albopictus populations and possible phylogenetic reasons for the recent invasion of Aedes aegypti in Nepal. Parasit Vectors 2020; 13:213. [PMID: 32321546 PMCID: PMC7178601 DOI: 10.1186/s13071-020-04090-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/15/2020] [Indexed: 01/03/2023] Open
Abstract
Background When the first systematic list of mosquitoes in Nepal was reported in 1990, there was no description of Aedes aegypti (L.), while Aedes albopictus (Skuse) has been included in the Stegomyia subgroup since the 1950s. The first record of Ae. aegypti in Nepal was reported in 2009, suggesting some coincidence between the invasion of this species and the first record of dengue fever in Nepal in 2006. Results We performed a field survey of the distribution and insecticide susceptibility of Ae. aegypti and Ae. albopictus in Nepal in 2017 and 2018. Mosquito larvae were collected from used tires located along the streets of Kathmandu, Bharatpur and Pokhara, and a simplified bioassay was used to assess the susceptibility of the larvae to pyrethroid insecticides using d-allethrin. The presence or absence of point mutations in the voltage-gated sodium channel was also detected by direct sequencing. V1016G was detected at a high frequency and a strong correlation was observed between the frequencies of V1016G and susceptibility indices in Ae. aegypti populations. F1534C was also detected at a relatively low frequency. In Ae. albopictus populations, susceptibilities to d-allethrin were high and no point mutations were detected. Analysis of the cytochrome c oxidase subunit 1 (cox1) gene was performed for assessing genetic diversity and the existence of two strains were identified in Ae. aegypti populations. One consisted of 9 globally-distributed haplotypes while the other was derived from an African haplotype. Conclusions The high pyrethroid resistance, high V1016G frequency, and relatively low quantity of insecticides used to control dengue vectors in Nepal may have resulted in only weak selection pressure favoring insecticide resistance and could support the hypothesis that this species has recently been introduced from neighboring Asian countries where pyrethroid resistance is relatively widespread.![]()
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Affiliation(s)
- Hitoshi Kawada
- Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
| | - Kyoko Futami
- Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Yukiko Higa
- Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.,Departmanet of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Ganesh Rai
- Shi-Gan International College of Science and Technology, Kathmandu, Nepal
| | - Takashi Suzuki
- Faculty of Health Science, Kobe-Tokiwa University, Kobe, Japan.,Division of Medical Informatics and Bioinformatics, Kobe University Hospital, Kobe, Japan
| | - Shiba Kumar Rai
- Shi-Gan International College of Science and Technology, Kathmandu, Nepal.,Research Division, Nepal Medical College, Gokarneswor, Kathmandu, Nepal
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Fan Y, O'Grady P, Yoshimizu M, Ponlawat A, Kaufman PE, Scott JG. Evidence for both sequential mutations and recombination in the evolution of kdr alleles in Aedes aegypti. PLoS Negl Trop Dis 2020; 14:e0008154. [PMID: 32302303 PMCID: PMC7164583 DOI: 10.1371/journal.pntd.0008154] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 02/19/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Aedes aegypti is a globally distributed vector of human diseases including dengue, yellow fever, chikungunya, and Zika. Pyrethroid insecticides are the primary means of controlling adult A. aegypti populations to suppress arbovirus outbreaks, but resistance to pyrethroid insecticides has become a global problem. Mutations in the voltage-sensitive sodium channel (Vssc) gene are a major mechanism of pyrethroid resistance in A. aegypti. Vssc resistance alleles in A. aegypti commonly have more than one mutation. However, our understanding of the evolutionary dynamics of how alleles with multiple mutations arose is poorly understood. METHODOLOGY/PRINCIPAL FINDINGS We examined the geographic distribution and association between the common Vssc mutations (V410L, S989P, V1016G/I and F1534C) in A. aegypti by analyzing the relevant Vssc fragments in 25 collections, mainly from Asia and the Americas. Our results showed all 11 Asian populations had two types of resistance alleles: 1534C and 989P+1016G. The 1534C allele was more common with frequencies ranging from 0.31 to 0.88, while the 989P+1016G frequency ranged from 0.13 to 0.50. Four distinct alleles (410L, 1534C, 410L+1534C and 410L+1016I+1534C) were detected in populations from the Americas. The most common was 410L+1016I+1534C with frequencies ranging from 0.50 to 1.00, followed by 1534C with frequencies ranging from 0.13 to 0.50. Our phylogenetic analysis of Vssc supported multiple independent origins of the F1534C mutation. Our results indicated the 410L+1534C allele may have arisen by addition of the V410L mutation to the 1534C allele, or by a crossover event. The 410L+1016I+1534C allele was the result of one or two mutational steps from a 1534C background. CONCLUSIONS/SIGNIFICANCE Our data corroborated previous geographic distributions of resistance mutations and provided evidence for both recombination and sequential accumulation of mutations contributing to the molecular evolution of resistance alleles in A. aegypti.
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Affiliation(s)
- Yinjun Fan
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, New York, United States of America
| | - Patrick O'Grady
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, New York, United States of America
| | - Melissa Yoshimizu
- Vector-Borne Disease Section, Division of Communicable Disease Control, Center for Infectious Diseases, California Department of Public Health, Sacramento, California, United States of America
| | | | - Phillip E. Kaufman
- Entomology and Nematology Department, University of Florida, Gainesville, Florida, United States of America
| | - Jeffrey G. Scott
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, New York, United States of America
- * E-mail:
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Cosme LV, Gloria-Soria A, Caccone A, Powell JR, Martins AJ. Evolution of kdr haplotypes in worldwide populations of Aedes aegypti: Independent origins of the F1534C kdr mutation. PLoS Negl Trop Dis 2020; 14:e0008219. [PMID: 32298261 PMCID: PMC7188295 DOI: 10.1371/journal.pntd.0008219] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 04/28/2020] [Accepted: 03/13/2020] [Indexed: 01/30/2023] Open
Abstract
Aedes aegypti is the primary vector of dengue, chikungunya, Zika, and urban yellow fever. Insecticides are often the most effective tools to rapidly decrease the density of vector populations, especially during arbovirus disease outbreaks. However, the intense use of insecticides, particularly pyrethroids, has selected for resistant mosquito populations worldwide. Mutations in the voltage gated sodium channel (NaV) are among the principal mechanisms of resistance to pyrethroids and DDT, also known as “knockdown resistance,” kdr. Here we report studies on the origin and dispersion of kdr haplotypes in samples of Ae. aegypti from its worldwide distribution. We amplified the IIS6 and IIIS6 NaV segments from pools of Ae. aegypti populations from 15 countries, in South and North America, Africa, Asia, Pacific, and Australia. The amplicons were barcoded and sequenced using NGS Ion Torrent. Output data were filtered and analyzed using the bioinformatic pipeline Seekdeep to determine frequencies of the IIS6 and IIIS6 haplotypes per population. Phylogenetic relationships among the haplotypes were used to infer whether the kdr mutations have a single or multiple origin. We found 26 and 18 haplotypes, respectively for the IIS6 and IIIS6 segments, among which were the known kdr mutations 989P, 1011M, 1016I and 1016G (IIS6), 1520I, and 1534C (IIIS6). The highest diversity of haplotypes was found in African samples. Kdr mutations 1011M and 1016I were found only in American and African populations, 989P + 1016G and 1520I + 1534C in Asia, while 1534C was present in samples from all continents, except Australia. Based primarily on the intron sequence, IIS6 haplotypes were subdivided into two well-defined clades (A and B). Subsequent phasing of the IIS6 + IIIS6 haplotypes indicates two distinct origins for the 1534C kdr mutation. These results provide evidence of kdr mutations arising de novo at specific locations within the Ae. aegypti geographic distribution. In addition, our results suggest that the 1534C kdr mutation had at least two independent origins. We can thus conclude that insecticide selection pressure with DDT and more recently with pyrethroids is selecting for independent convergent mutations in NaV. Insecticide resistance is a global threat for the control of Aedes aegypti, the mosquito vector of aboviruses such as dengue, chikungunya and Zika. Mutations in the voltage gated sodium channel (NaV), known as kdr, are one of the principal mechanisms related to resistance to pyrethroids, the class of insecticide most employed worldwide inside and around residences. We investigate whether the same kdr mutations found in Ae. aegypti populations from distinct regions of the world have a common origin and subsequently dispersed or if they emerged in unrelated populations at distinct moments. By evaluating the sequences of two fragments of the NaV gene, obtained from DNA collections of Ae. aegypti from several countries, we found at least two independent origins for the F1534C kdr mutation in American, African and Asian populations. There was no evidence for multiple origins of the common kdr mutations V1016I and P989S + V1016G, which were exclusive to American and Asian populations. Our results increase our knowledge of insecticide resistance evolution in one of the main arboviral mosquito vectors of major global diseases.
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Affiliation(s)
| | - Andrea Gloria-Soria
- Yale University, New Haven, CT, United States of America
- Center for Vector Biology & Zoonotic Diseases. The Connecticut Agricultural Experiment Station, New Haven, CT, United States of America
| | | | | | - Ademir Jesus Martins
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz/ FIOCRUZ, Av Brasil, Rio de Janeiro, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, INCT-EM, UFRJ, Rio de Janeiro, RJ, Brazil
- * E-mail:
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Distribution of insecticide resistance and mechanisms involved in the arbovirus vector Aedes aegypti in Laos and implication for vector control. PLoS Negl Trop Dis 2019; 13:e0007852. [PMID: 31830027 PMCID: PMC6932826 DOI: 10.1371/journal.pntd.0007852] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 12/26/2019] [Accepted: 10/16/2019] [Indexed: 12/13/2022] Open
Abstract
Background The yellow fever mosquito Aedes aegypti is the major vector of dengue, yellow fever, Zika, and Chikungunya viruses. Worldwide vector control is largely based on insecticide treatments but, unfortunately, vector control programs are facing operational challenges due to mosquitoes becoming resistant to commonly used insecticides. In Southeast Asia, resistance of Ae. aegypti to chemical insecticides has been documented in several countries but no data regarding insecticide resistance has been reported in Laos. To fill this gap, we assessed the insecticide resistance of 11 Ae. aegypti populations to larvicides and adulticides used in public health operations in the country. We also investigated the underlying molecular mechanisms associated with resistance, including target site mutations and detoxification enzymes putatively involved in metabolic resistance. Methods and results Bioassays on adults and larvae collected in five provinces revealed various levels of resistance to organophosphates (malathion and temephos), organochlorine (DDT) and pyrethroids (permethrin and deltamethrin). Synergist bioassays showed a significant increased susceptibility of mosquitoes to insecticides after exposure to detoxification enzyme inhibitors. Biochemical assays confirmed these results by showing significant elevated activities of cytochrome P450 monooxygenases (P450), glutathione S-transferases (GST) and carboxylesterases (CCE) in adults. Two kdr mutations, V1016G and F1534C, were detected by qPCR at low and high frequency, respectively, in all populations tested. A significant negative association between the two kdr mutations was detected. No significant association between kdr mutations frequency (for both 1534C and 1016G) and survival rate to DDT or permethrin (P > 0.05) was detected. Gene Copy Number Variations (CNV) were detected for particular detoxification enzymes. At the population level, the presence of CNV affecting the carboxylesterase CCEAE3A and the two cytochrome P450 CYP6BB2 and CYP6P12 were significantly correlated to insecticide resistance. Conclusions These results suggest that both kdr mutations and metabolic resistance mechanisms are present in Laos but their impact on phenotypic resistance may differ in proportion at the population or individual level. Molecular analyses suggest that CNV affecting CCEAE3A previously associated with temephos resistance is also associated with malathion resistance while CNV affecting CYP6BB2 and CYP6P12 are associated with pyrethroid and possibly DDT resistance. The presence of high levels of insecticide resistance in the main arbovirus vector in Laos is worrying and may have important implications for dengue vector control in the country. Aedes aegypti is the major vector of dengue in Laos and the control of this vector rely mainly on insecticide treatments. Compared to the neighboring countries, where resistance has been detected, there was no data on the distribution, the levels, and the mechanisms involved in the resistance in Laos. Laboratory bioassays showed that resistance to the currently used larvicides (temephos) and adulticides (pyrethroids) was present at different levels and distributed throughout the country. This may have important implications for dengue vector control in Laos. The mechanisms underlying the resistance were determined to be both metabolic and target site mutations (kdr) supporting results found in other countries. Several key detoxification enzyme genes were identified as potential candidates for metabolic resistance. This study provides a baseline on insecticide resistance in Laos and will help the Public Health authorities in designing more adapted vector control strategies.
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Smith LB, Sears C, Sun H, Mertz RW, Kasai S, Scott JG. CYP-mediated resistance and cross-resistance to pyrethroids and organophosphates in Aedes aegypti in the presence and absence of kdr. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2019; 160:119-126. [PMID: 31519246 DOI: 10.1016/j.pestbp.2019.07.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/09/2019] [Accepted: 07/24/2019] [Indexed: 06/10/2023]
Abstract
Aedes aegypti thrives in urban environments and transmits several debilitating human viral diseases. Thus, our ability to control this mosquito species in endemic areas is of utmost importance. The use of insecticides, mostly pyrethroids and organophosphates (OPs), has long been the primary means of controlling A. aegypti, but widespread insecticide resistance has emerged. The two main mechanisms of pyrethroid resistance in A. aegypti are CYP-mediated detoxification and mutations in the target site, voltage-sensitive sodium channel (Vssc), referred to as knockdown resistance (kdr). Knowledge about the contributions and interactions of these mechanisms to resistance is important for the understanding of the molecular and evolutionary basis of insecticide resistance, and to determine the effectiveness of insecticides. In this study, we address two aims: 1) determine the patterns of CYP-mediated cross-resistance to pyrethroid and OP insecticides, both in the presence and absence of kdr (S989P + V1016G), and 2) determine whether the interaction between the two mechanisms yields a greater than, less than, or additive effect on resistance. We tested seven pyrethroids and four OPs against three congenic strains of A. aegypti: ROCK (susceptible), CYP:ROCK (CR) (resistant due to CYP-mediated detoxification without kdr), and CYP + KDR:ROCK (CKR) (resistant due to both CYPs and kdr), and compared these to the congenic KDR:ROCK strain that was previously reported. We found that resistance ratios (RRs) were variable between pyrethroids and strains, ranging from 6.2- to 42-fold for CR, and 70- to 261-fold for CKR. In general, we found that CYP-mediated resistance alone contributes less to resistance than kdr. The effect of the combined mechanisms on resistance was significantly greater than additive for all pyrethroids except (1R)-trans-fenfluthrin. CYP-mediated pyrethroid resistance conferred cross-resistance to both methyl paraoxon and fenitrothion, and negative cross-resistance to methyl parathion and naled. Based on our results, we recommend that etofenprox and cyfluthrin be avoided for A. aegypti control in areas where these two resistance mechanisms are prevalent.
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Affiliation(s)
- Letícia B Smith
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, NY, USA
| | - Colin Sears
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, NY, USA
| | - Haina Sun
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, NY, USA
| | - Robert W Mertz
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, NY, USA
| | - Shinji Kasai
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, NY, USA; Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjukuku, Tokyo, Japan
| | - Jeffrey G Scott
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, NY, USA.
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Insecticide resistance in Aedes aegypti: An impact from human urbanization? PLoS One 2019; 14:e0218079. [PMID: 31233517 PMCID: PMC6590797 DOI: 10.1371/journal.pone.0218079] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 05/24/2019] [Indexed: 01/16/2023] Open
Abstract
In the city of Magelang, Indonesia, the distribution of Dengue Haemorhagic Fever (DHF) cases tend to be clustered, ever changing along with human urbanization from 2014 to 2017. Although DHF cases have been less reported in the city of Magelang for the past 5 years, vector control measures by using insecticide space spraying, particularly permethrin, have been continuously performed. Current study aimed to detect kdr mutations associated with pyrethroid resistance in Ae. aegypti and to study possible association between insecticide resistance and DHF case distribution related to human urbanization. The study was a cross sectional study conducted in 3 sub-districts in the city of Magelang, Central Java, Indonesia. Eggs of Ae. aegypti collected from 195 sample households were reared and were tested for resistance to pyrethroids by using PCR. Primers AaSCF1 and AaSCR4, and primers AaSCF7 and AaSCR7 were used in detecting presence of mutation in VGSC IIS6 and IIIS6 gene, respectively. Fragments of amplified DNA were sequenced and were analyzed. Spatio-temporal using Standard Deviational Ellipse (SDE) was performed to obtain mapping of DHF case distribution trends. The total number of DHF case was 380 cases, with the most cases (158) occurred in 2015 and the least cases (66) reported in 2017. DHF case distribution was grouped into several clusters. SDE calculation demonstrated movement of DHF case in the direction to principal arterial road, suggesting link to urbanization. Gene sequencing demonstrated VGSC IIS6 gene mutation (S989P and V1016G) in Ae. aegypti collected from study areas, indicating resistance to permethrin. VGSC IIIS6 gene mutation was not found. Current study concluded that multiple kdr mutations associated with resistance to pyrethroid was detected in Ae. aegypti, and that human urbanization may have a role in the development of such resistance.
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