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Chuchuy A, Rodriguero MS, Alonso AC, Stein M, Micieli MV. Wolbachia infection in natural mosquito populations from Argentina. Parasitol Res 2024; 123:343. [PMID: 39382727 DOI: 10.1007/s00436-024-08352-5] [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: 05/03/2024] [Accepted: 09/16/2024] [Indexed: 10/10/2024]
Abstract
The increasing spread of mosquito vectors has made mosquito-borne arboviral diseases a global threat to public health, leading to the urgent need for effective population control methods. Strategies based in the intracellular bacterium Wolbachia Hertig, 1936 are considered environmentally friendly, safe for humans, and potentially cost-effective for controlling arboviral diseases. To minimize undesirable side effects, it is relevant to assess whether Wolbachia is present in the area and understand the diversity associated with native infections before implementing these strategies. With this purpose, we investigated Wolbachia infection status, diversity, and prevalence in populations of Aedes albifasciatus (Macquart, 1838), Aedes fluviatilis (Lutz, 1904), and hybrids of the Culex pipiens (Linnaeus, 1758) complex from Argentina. Aedes albifasciatus and C. pipiens complex samples were collected in the province of Buenos Aires, and A. fluviatilis in the province of Misiones. Aedes albifasciatus was found to be uninfected, while infections with strains wFlu and wPip were detected in A. fluviatilis and hybrids of the C. pipiens complex, respectively. All strains were fixed or close to fixation and clustered within supergroup B. These finding provides valuable information on Wolbachia strains found in natural mosquito populations in Argentina that might be used in heterologous infections in the future or be considered when designing control strategies based on Wolbachia infection.
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Affiliation(s)
- Ailen Chuchuy
- Centro de Estudios Parasitológicos y de Vectores, CONICET (CEPAVE-CCT-La Plata-CONICET-UNLP), Boulevard 120 e/61y 62, 1900, La Plata, Argentina
| | - Marcela S Rodriguero
- Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, 1428, Autonomous City of Buenos Aires, Argentina.
- Instituto de Ecología, Genética y Evolución (IEGEBA), Universidad de Buenos Aires, CONICET, Intendente Güiraldes 2160, 1428, Autonomous City of Buenos Aires, Argentina.
| | - Ana C Alonso
- Laboratorio de Entomología, Instituto de Medicina Regional, Universidad Nacional del Nordeste, CONICET (CCT Nordeste-CONICET-UNNE), Av. Las Heras 727, 3500, Resistencia, Argentina
- Instituto de Investigaciones en Energía No Convencional, Universidad Nacional de Salta, CONICET (INENCO-CONICET), Salta, Argentina
| | - Marina Stein
- Laboratorio de Entomología, Instituto de Medicina Regional, Universidad Nacional del Nordeste, CONICET (CCT Nordeste-CONICET-UNNE), Av. Las Heras 727, 3500, Resistencia, Argentina
| | - María V Micieli
- Centro de Estudios Parasitológicos y de Vectores, CONICET (CEPAVE-CCT-La Plata-CONICET-UNLP), Boulevard 120 e/61y 62, 1900, La Plata, Argentina
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Cheong YL, Nazni WA, Lee HL, NoorAfizah A, MohdKhairuddin IC, Kamarul GMR, Nizam NMN, Arif MAK, NurZatilAqmar ZM, Irwan SM, Khadijah K, Paid YM, Topek O, Hasnor AH, AbuBakar R, Singh Gill B, Fadzilah K, Tahir A, Sinkins SP, Hoffmann AA. Spatial Distribution and Long-Term Persistence of Wolbachia-Infected Aedes aegypti in the Mentari Court, Malaysia. INSECTS 2023; 14:373. [PMID: 37103189 PMCID: PMC10146232 DOI: 10.3390/insects14040373] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/11/2023] [Accepted: 03/20/2023] [Indexed: 06/19/2023]
Abstract
Dengue is endemic in Malaysia, and vector control strategies are vital to reduce dengue transmission. The Wolbachia strain wAlbB carried by both sexes of Ae. aegypti was released in Mentari Court, a high-rise residential site, in October 2017 and stopped after 20 weeks. Wolbachia frequencies are still being monitored at multiple traps across this site, providing an opportunity to examine the spatiotemporal distribution of Wolbachia and mosquito density with respect to year, residential block, and floor, using spatial interpolation in ArcGIS, GLMs, and contingency analyses. In just 12 weeks, Wolbachia-infected mosquitoes were established right across the Mentari Court site with an overall infection frequency of >90%. To date, the Wolbachia frequency of Ae. aegypti has remained high in all areas across the site despite releases finishing four years ago. Nevertheless, the Wolbachia invaded more rapidly in some residential blocks than others, and also showed a relatively higher frequency on the eighth floor. The Ae. aegypti index tended to differ somewhat between residential blocks, whilst the Ae. albopictus index was relatively higher at the top and bottom floors of buildings. In Mentari Court, only a short release period was required to infiltrate Wolbachia completely and stably into the natural population. The results inform future releases in comparable sites in a dengue control programme.
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Affiliation(s)
- Yoon Ling Cheong
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Wasi A. Nazni
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Han Lim Lee
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Ahmad NoorAfizah
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Ibrahim C. MohdKhairuddin
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Ghazali M. R. Kamarul
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Nasir M. N. Nizam
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Mohd A. K. Arif
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Zabari M. NurZatilAqmar
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Saidin M. Irwan
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Khairuddin Khadijah
- Petaling District Health Office, Ministry of Health Malaysia, SS 6, Petaling Jaya 47301, Selangor, Malaysia
| | - Yusof M. Paid
- Petaling District Health Office, Ministry of Health Malaysia, SS 6, Petaling Jaya 47301, Selangor, Malaysia
| | - Omar Topek
- Federal Territory Health Department of Kuala Lumpur and Putrajaya, Ministry of Health Malaysia, Jalan Cenderasari, Tasik Perdana, Kuala Lumpur 50480, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Asim H. Hasnor
- Institute for Health Behavioural Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Setia Murni U13/52, Seksyen U13 Setia Alam, Shah Alam 40170, Selangor, Malaysia
| | - Rahman AbuBakar
- Institute for Health Behavioural Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Setia Murni U13/52, Seksyen U13 Setia Alam, Shah Alam 40170, Selangor, Malaysia
| | - Balvinder Singh Gill
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Kamaludin Fadzilah
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Aris Tahir
- Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur 50588, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Steven P. Sinkins
- MRC—University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Ary A. Hoffmann
- Bio21 Institute and the School of BioSciences, University of Melbourne, 30 Flemington Road, Parkville, VIC 3052, Australia
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Pagendam D, Elfekih S, Nassar MS, Nelson S, Almalik AM, Tawfik EA, Al-Fageeh MB, Hoffmann AA. Spatio-Temporal Modelling Informing Wolbachia Replacement Releases in a Low Rainfall Climate. INSECTS 2022; 13:949. [PMID: 36292897 PMCID: PMC9604250 DOI: 10.3390/insects13100949] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/13/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
Releases of Aedes aegypti carrying Wolbachia bacteria are known to suppress arbovirus transmission and reduce the incidence of vector-borne diseases. In planning for Wolbachia releases in the arid environment of Jeddah, Saudi Arabia, we collected entomological data with ovitraps across a 7-month period in four locations. Herein, we show that mosquito presence in basements does not differ from that of non-basement areas of buildings. In modelling mosquito presence across the study sites, we found the spatial structure to be statistically significant in one of the four sites, while a significant spatial structure was found for egg production data across three of the four sites. The length scales of the spatial covariance functions fitted to the egg production data ranged from 143 m to 574 m, indicating that high productivity regions can be extensive in size. Rank-correlation analyses indicated that mosquito presence tended to persist from the dry to wet season, but that egg production ranks at locations could reverse. The data suggest that, in Jeddah, the quality of the local environment for breeding can vary over time. The data support the feasibility of dry season releases but with release numbers needing to be flexible depending on local rates of invasion.
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Affiliation(s)
- Dan Pagendam
- CSIRO Data61, Dutton Park, Brisbane, QLD 4101, Australia
| | - Samia Elfekih
- CSIRO H&B, Australian Centre for Disease Preparedness (ACDP), Geelong, VIC 3052, Australia
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of Biosciences, University of Melbourne, Parkville, VIC 3052, Australia
| | - Majed S. Nassar
- King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Samuel Nelson
- CSIRO Data61, Black Mountain, Canberra, ACT 2601, Australia
| | - Abdulaziz M. Almalik
- King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Essam A. Tawfik
- King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Mohamed B. Al-Fageeh
- King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Ary A. Hoffmann
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of Biosciences, University of Melbourne, Parkville, VIC 3052, Australia
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Regilme MAF, Carvajal TM, Honnen A, Amalin DM, Watanabe K. The influence of roads on the fine-scale population genetic structure of the dengue vector Aedes aegypti (Linnaeus). PLoS Negl Trop Dis 2021; 15:e0009139. [PMID: 33635860 PMCID: PMC7946359 DOI: 10.1371/journal.pntd.0009139] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 03/10/2021] [Accepted: 01/13/2021] [Indexed: 11/30/2022] Open
Abstract
Dengue is endemic in tropical and subtropical countries and is transmitted mainly by Aedes aegypti. Mosquito movement can be affected by human-made structures such as roads that can act as a barrier. Roads can influence the population genetic structure of Ae. aegypti. We investigated the genetic structure and gene flow of Ae. aegypti as influenced by a primary road, España Boulevard (EB) with 2000-meter-long stretch and 24-meters-wide in a very fine spatial scale. We hypothesized that Ae. aegypti populations separated by EB will be different due to the limited gene flow as caused by the barrier effect of the road. A total of 359 adults and 17 larvae Ae. aegypti were collected from June to September 2017 in 13 sites across EB. North (N1-N8) and South (S1-S5) comprised of 211 and 165 individuals, respectively. All mosquitoes were genotyped at 11 microsatellite loci. AMOVA FST indicated significant genetic differentiation across the road. The constructed UPGMA dendrogram found 3 genetic groups revealing the clear separation between North and South sites across the road. On the other hand, Bayesian cluster analysis showed four genetic clusters (K = 4) wherein each individual samples have no distinct genetic cluster thus genetic admixture. Our results suggest that human-made landscape features such as primary roads are potential barriers to mosquito movement thereby limiting its gene flow across the road. This information is valuable in designing an effective mosquito control program in a very fine spatial scale.
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Affiliation(s)
- Maria Angenica F. Regilme
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Japan
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Japan
- Biological Control Research Unit, Center for Natural Science and Environmental Research, De La Salle University, Manila, Philippines
- Department of Biology, De La Salle University, Manila, Philippines
| | - Thaddeus M. Carvajal
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Japan
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Japan
- Biological Control Research Unit, Center for Natural Science and Environmental Research, De La Salle University, Manila, Philippines
- Department of Biology, De La Salle University, Manila, Philippines
| | - Ann–Christin Honnen
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Divina M. Amalin
- Biological Control Research Unit, Center for Natural Science and Environmental Research, De La Salle University, Manila, Philippines
- Department of Biology, De La Salle University, Manila, Philippines
| | - Kozo Watanabe
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Japan
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Japan
- Biological Control Research Unit, Center for Natural Science and Environmental Research, De La Salle University, Manila, Philippines
- Department of Biology, De La Salle University, Manila, Philippines
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Environmental influences on Aedes aegypti catches in Biogents Sentinel traps during a Californian "rear and release" program: Implications for designing surveillance programs. PLoS Negl Trop Dis 2020; 14:e0008367. [PMID: 32530921 PMCID: PMC7314095 DOI: 10.1371/journal.pntd.0008367] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 06/24/2020] [Accepted: 05/06/2020] [Indexed: 01/13/2023] Open
Abstract
As Aedes aegypti continues to expand its global distribution, the diseases it vectors (dengue, Zika, chikungunya and yellow fever) are of increasing concern. Modern efforts to control this species include "rear and release" strategies where lab-reared mosquitoes are distributed throughout the landscape to replace or suppress invasive populations. These programs require intensive surveillance efforts to monitor their success, and the Biogents Sentinel (BGS) trap is one of the most effective tools for sampling adult Ae. aegypti. BGS trap catches can be highly variable throughout landscapes, so we investigated the potential impacts of environmental factors on adult Ae. aegypti capture rates during a "rear and release" program in California to better understand the relative contributions of true variability in population density across a landscape and trap context. We recorded male and female Ae. aegypti catches from BGS traps, with and without CO2, throughout control sites where no mosquitoes were released and in treatment sites where males infected with Wolbachia were released. BGS trap catches were positively influenced by higher proportions of shade or bushes in the front yard of the premises as well as the presence of potential larval habitats such as subterranean vaults. In contrast, an increase in residential habitat within a 100 m radius of trap locations negatively influenced BGS trap catches. For male Ae. aegypti, increased visual complexity of the trap location positively influenced capture rates, and the presence of yard drains negatively affected catch rates in control sites. Lastly, for BGS traps using CO2, higher catch rates were noted from traps placed greater than one meter from walls or fences for both male and female mosquitoes. These results have important implications for surveillance programs of Ae. aegypti throughout the Californian urban environment including adult monitoring during "rear and release" programs.
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Staunton KM, Yeeles P, Townsend M, Nowrouzi S, Paton CJ, Trewin B, Pagendam D, Bondarenco A, Devine GJ, Snoad N, Beebe NW, Ritchie SA. Trap Location and Premises Condition Influences on Aedes aegypti (Diptera: Culicidae) Catches Using Biogents Sentinel Traps During a 'Rear and Release' Program: Implications for Designing Surveillance Programs. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:1102-1111. [PMID: 30817823 DOI: 10.1093/jme/tjz018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Indexed: 06/09/2023]
Abstract
As the incidence of arboviral diseases such as dengue, Zika, chikungunya, and yellow fever increases globally, controlling their primary vector, Aedes aegypti (L.) (Diptera: Culicidae), is of greater importance than ever before. Mosquito control programs rely heavily on effective adult surveillance to ensure methodological efficacy. The Biogents Sentinel (BGS) trap is the gold standard for surveilling adult Aedes mosquitoes and is commonly deployed worldwide, including during modern 'rear and release' programs. Despite its extensive use, few studies have directly assessed environmental characteristics that affect BGS trap catches, let alone how these influences change during 'rear and release' programs. We assessed male and female Ae. aegypti spatial stability, as well as premises condition and trap location influences on BGS trap catches, as part of Debug Innisfail 'rear and release' program in northern Australia. We found similar trends in spatial stability of male and female mosquitoes at both weekly and monthly resolutions. From surveillance in locations where no males were released, reduced catches were found at premises that contained somewhat damaged houses and unscreened properties. In addition, when traps were located in areas that were unsheltered, more than 10 m from commonly used sitting areas or more visually complex catches were also negatively affected. In locations where males were released, we found that traps in treatment sites, relative to control sites, displayed increased catches in heavily shaded premises and were inconsistently influenced by differences in house sets and building materials. Such findings have valuable implications for a range of Ae. aegypti surveillance programs.
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Affiliation(s)
- Kyran M Staunton
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Smithfield, QLD, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD, Australia
| | - Peter Yeeles
- College of Science and Engineering, James Cook University, Smithfield, QLD, Australia
| | - Michael Townsend
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Smithfield, QLD, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD, Australia
| | - Somayeh Nowrouzi
- College of Science and Engineering, James Cook University, Smithfield, QLD, Australia
| | - Christopher J Paton
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Smithfield, QLD, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD, Australia
| | | | | | | | - Gregor J Devine
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Nigel Snoad
- Verily Life Sciences, South San Francisco, CA
| | - Nigel W Beebe
- Health and Biosecurity, CSIRO, Brisbane, QLD, Australia
- School of Biological Sciences Faculty of Science, University of Queensland, St Lucia, Brisbane, QLD, Australia
| | - Scott A Ritchie
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Smithfield, QLD, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD, Australia
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Dorigatti I, McCormack C, Nedjati-Gilani G, Ferguson NM. Using Wolbachia for Dengue Control: Insights from Modelling. Trends Parasitol 2018; 34:102-113. [PMID: 29183717 PMCID: PMC5807169 DOI: 10.1016/j.pt.2017.11.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 11/01/2017] [Accepted: 11/02/2017] [Indexed: 12/23/2022]
Abstract
Dengue is the most common arboviral infection of humans, responsible for a substantial disease burden across the tropics. Traditional insecticide-based vector-control programmes have limited effectiveness, and the one licensed vaccine has a complex and imperfect efficacy profile. Strains of the bacterium Wolbachia, deliberately introduced into Aedes aegyptimosquitoes, have been shown to be able to spread to high frequencies in mosquito populations in release trials, and mosquitoes infected with these strains show markedly reduced vector competence. Thus, Wolbachia represents an exciting potential new form of biocontrol for arboviral diseases, including dengue. Here, we review how mathematical models give insight into the dynamics of the spread of Wolbachia, the potential impact of Wolbachia on dengue transmission, and we discuss the remaining challenges in evaluation and development.
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Affiliation(s)
- Ilaria Dorigatti
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London W2 1PG, UK; These authors made equal contributions
| | - Clare McCormack
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London W2 1PG, UK; These authors made equal contributions
| | - Gemma Nedjati-Gilani
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London W2 1PG, UK; These authors made equal contributions
| | - Neil M Ferguson
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London W2 1PG, UK.
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Suh E, Mercer DR, Dobson SL. Life-shortening Wolbachia infection reduces population growth of Aedes aegypti. Acta Trop 2017; 172:232-239. [PMID: 28506794 DOI: 10.1016/j.actatropica.2017.05.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 05/10/2017] [Accepted: 05/11/2017] [Indexed: 12/11/2022]
Abstract
Wolbachia bacteria are being introduced into natural populations of vector mosquitoes, with the goal of reducing the transmission of human diseases such as Zika and dengue fever. The successful establishment of Wolbachia infection is largely dependent on the effects of Wolbachia infection to host fitness, but the effects of Wolbachia infection on the individual life-history traits of immature mosquitoes can vary. Here, the effects of life-shortening Wolbachia (wMelPop) on population growth of infected individuals were evaluated by measuring larval survival, developmental time and adult size of Aedes aegypti in intra- (infected or uninfected only) and inter-group (mixed with infected and uninfected) larval competition assays. At low larval density conditions, the population growth of wMelPop infected and uninfected individuals was similar. At high larval densities, wMelPop infected individuals had a significantly reduced population growth rate relative to uninfected individuals, regardless of competition type. We discuss the results in relation to the invasion of the wMelPop Wolbachia infection into naturally uninfected populations.
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Schmidt TL, Barton NH, Rašić G, Turley AP, Montgomery BL, Iturbe-Ormaetxe I, Cook PE, Ryan PA, Ritchie SA, Hoffmann AA, O’Neill SL, Turelli M. Local introduction and heterogeneous spatial spread of dengue-suppressing Wolbachia through an urban population of Aedes aegypti. PLoS Biol 2017; 15:e2001894. [PMID: 28557993 PMCID: PMC5448718 DOI: 10.1371/journal.pbio.2001894] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 04/17/2017] [Indexed: 11/30/2022] Open
Abstract
Dengue-suppressing Wolbachia strains are promising tools for arbovirus control, particularly as they have the potential to self-spread following local introductions. To test this, we followed the frequency of the transinfected Wolbachia strain wMel through Ae. aegypti in Cairns, Australia, following releases at 3 nonisolated locations within the city in early 2013. Spatial spread was analysed graphically using interpolation and by fitting a statistical model describing the position and width of the wave. For the larger 2 of the 3 releases (covering 0.97 km2 and 0.52 km2), we observed slow but steady spatial spread, at about 100–200 m per year, roughly consistent with theoretical predictions. In contrast, the smallest release (0.11 km2) produced erratic temporal and spatial dynamics, with little evidence of spread after 2 years. This is consistent with the prediction concerning fitness-decreasing Wolbachia transinfections that a minimum release area is needed to achieve stable local establishment and spread in continuous habitats. Our graphical and likelihood analyses produced broadly consistent estimates of wave speed and wave width. Spread at all sites was spatially heterogeneous, suggesting that environmental heterogeneity will affect large-scale Wolbachia transformations of urban mosquito populations. The persistence and spread of Wolbachia in release areas meeting minimum area requirements indicates the promise of successful large-scale population transformation. Wolbachia are bacteria that live inside insect cells. In insects that act as viral vectors, Wolbachia can suppress virus transmission to new hosts. Wolbachia have been experimentally introduced into Aedes aegypti mosquito populations to reduce the transmission of dengue, Zika, and other arboviruses that cause human disease. Wolbachia invade populations by causing cytoplasmic incompatibility, a phenomenon whereby embryos from crosses between infected males and uninfected females fail to hatch. While Wolbachia have been shown to successfully invade and remain established in isolated Ae. aegypti populations, outward spread from urban release zones has not been previously documented. This is an important step in demonstrating that Wolbachia can be used to combat mosquito-borne infectious disease in cities. Here we describe Wolbachia spread from 2 introduction areas within Cairns in northeastern Australia at a rate of about 100–200 meters per year. Spread occurs only when introduction areas are sufficiently large. The slow rates of observed spread are broadly consistent with mathematical predictions based on estimated Ae. aegypti dispersal distances, Wolbachia dynamics, and effects seen in isolated populations. Spread is uneven and likely depends on local characteristics (e.g., barriers) that affect mosquito density and dispersal. Our data indicate that Wolbachia can be introduced locally in large cities, remain established where released, and slowly spread from release areas. These dynamics indicate that high Wolbachia infection frequencies can be established gradually across large urban areas through local releases.
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Affiliation(s)
- Tom L. Schmidt
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | | | - Gordana Rašić
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Andrew P. Turley
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, Australia
| | - Brian L. Montgomery
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, Australia
| | | | - Peter E. Cook
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, Australia
| | - Peter A. Ryan
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, Australia
| | - Scott A. Ritchie
- School of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Cairns, Queensland, Australia
| | - Ary A. Hoffmann
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Scott L. O’Neill
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, Australia
| | - Michael Turelli
- Department of Evolution and Ecology, University of California, Davis, Davis, California, United States of America
- * E-mail:
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Montgomery BL, Shivas MA, Hall-Mendelin S, Edwards J, Hamilton NA, Jansen CC, McMahon JL, Warrilow D, van den Hurk AF. Rapid Surveillance for Vector Presence (RSVP): Development of a novel system for detecting Aedes aegypti and Aedes albopictus. PLoS Negl Trop Dis 2017; 11:e0005505. [PMID: 28339458 PMCID: PMC5381943 DOI: 10.1371/journal.pntd.0005505] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 04/05/2017] [Accepted: 03/20/2017] [Indexed: 11/18/2022] Open
Abstract
Background The globally important Zika, dengue and chikungunya viruses are primarily transmitted by the invasive mosquitoes, Aedes aegypti and Aedes albopictus. In Australia, there is an increasing risk that these species may invade highly urbanized regions and trigger outbreaks. We describe the development of a Rapid Surveillance for Vector Presence (RSVP) system to expedite presence- absence surveys for both species. Methodology/Principal findings We developed a methodology that uses molecular assays to efficiently screen pooled ovitrap (egg trap) samples for traces of target species ribosomal RNA. Firstly, specific real-time reverse transcription-polymerase chain reaction (RT-PCR) assays were developed which detect a single Ae. aegypti or Ae. albopictus first instar larva in samples containing 4,999 and 999 non-target mosquitoes, respectively. ImageJ software was evaluated as an automated egg counting tool using ovitrap collections obtained from Brisbane, Australia. Qualitative assessment of ovistrips was required prior to automation because ImageJ did not differentiate between Aedes eggs and other objects or contaminants on 44.5% of ovistrips assessed, thus compromising the accuracy of egg counts. As a proof of concept, the RSVP was evaluated in Brisbane, Rockhampton and Goomeri, locations where Ae. aegypti is considered absent, present, and at the margin of its range, respectively. In Brisbane, Ae. aegypti was not detected in 25 pools formed from 477 ovitraps, comprising ≈ 54,300 eggs. In Rockhampton, Ae. aegypti was detected in 4/6 pools derived from 45 ovitraps, comprising ≈ 1,700 eggs. In Goomeri, Ae. aegypti was detected in 5/8 pools derived from 62 ovitraps, comprising ≈ 4,200 eggs. Conclusions/Significance RSVP can rapidly detect nucleic acids from low numbers of target species within large samples of endemic species aggregated from multiple ovitraps. This screening capability facilitates deployment of ovitrap configurations of varying spatial scales, from a single residential block to entire suburbs or towns. RSVP is a powerful tool for surveillance of invasive Aedes spp., validation of species eradication and quality assurance for vector control operations implemented during disease outbreaks. Aedes (Stegomyia) vectors of dengue, Zika and chikungunya viruses utilize artificial and natural containers as larval habitats. Adults do not usually disperse far (< 500 m) from these larval habitats in urban and peri-urban environments. Highly heterogeneous distributions raise significant logistic challenges to conduct informative surveillance. Public health imperatives require contemporaneous vector mosquito presence-absence data for highly urbanized regions that are both vulnerable to invasions and have frequent exposure to viremic travellers. We developed a promising tool to expedite presence-absence surveillance of Aedes aegypti and Aedes albopictus by integrating molecular diagnostics with ovitraps and automated egg quantification software. The high sensitivity of the molecular assays enabled samples from multiple ovitraps to be pooled and processed for each diagnostic test. This innovation resolves the considerable logistic constraints inherent in traditional ovitrap surveillance programs. Proof of concept was evaluated in field trials in Queensland geographies where Ae. aegypti is considered either absent, present or at the margin of its range (Brisbane, Rockhampton and Goomeri, respectively). Aedes aegypti was detected in Goomeri and Rockhampton and not detected in Brisbane. Further investigation is required to address the inaccuracy of automated egg counting software whenever contaminants are present. RSVP can accommodate varied ovitrap designs and deployment configurations, improves efficiency in laboratory and labor costs for high volumes of samples, and enables a rapid turnaround of results. The RSVP system can innovate surveillance programs for early-warning of invasion, eradication, and quality assurance for vector control in disease response contexts.
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Affiliation(s)
- Brian L. Montgomery
- Metro South Public Health Unit, Queensland Health, Coopers Plains, Queensland, Australia
| | - Martin A. Shivas
- Mosquito and Pest Management, Brisbane City Council, Fortitude Valley, Queensland, Australia
| | - Sonja Hall-Mendelin
- Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland Government, Coopers Plains, Queensland, Australia
| | - Jim Edwards
- Rockhampton Public Health Unit, Queensland Health, Rockhampton, Queensland, Australia
| | - Nicholas A. Hamilton
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland, Australia
| | - Cassie C. Jansen
- Metro North Public Health Unit, Queensland Health, Windsor, Queensland, Australia
| | - Jamie L. McMahon
- Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland Government, Coopers Plains, Queensland, Australia
| | - David Warrilow
- Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland Government, Coopers Plains, Queensland, Australia
| | - Andrew F. van den Hurk
- Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland Government, Coopers Plains, Queensland, Australia
- * E-mail:
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Wolbachia infections in mosquitoes and their predators inhabiting rice field communities in Thailand and China. Acta Trop 2016; 159:153-60. [PMID: 27012719 DOI: 10.1016/j.actatropica.2016.03.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 03/17/2016] [Accepted: 03/20/2016] [Indexed: 11/21/2022]
Abstract
Wolbachia are inherited, endocytoplasmic bacteria that infect a wide range of arthropods. Here is the first systematic report on the study of Wolbachia infection in mosquitoes and their predators from both Thailand and China. In Thailand, 632 mosquito specimens (20 spp.) and 424 insect predators (23 spp.) were collected from the rice agroecosystem, mostly from the Central region, followed by the Northeast, the North and the South and were inhabiting rice fields, wetlands and ditches. In China, 928 mosquitoes (15 spp.) and 149 insect predators (16 spp.) were collected from rice fields along the Weishan Lake in Shandong province. Specimens were classified in the orders Diptera, Coleoptera, Odonata and Hemiptera. Using wsp, ftsZ, 16S rRNA and groE gene amplifications, Wolbachia were detected in 12 mosquito spp. and 6 predator spp. from Thailand and 11 mosquito spp. and 5 predator spp. from China. The relative Wolbachia densities of these species were determined using quantitative real-time PCR. The mosquito, Aedes albopictus, and the predator, Agriocnemis femina, had the highest bacterial densities. These results imply that Wolbachia of supergroup B are distributed throughout these insects, probably via horizontal transmission in rice agroecosystems.
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Dutra HLC, Lopes da Silva V, da Rocha Fernandes M, Logullo C, Maciel-de-Freitas R, Moreira LA. The influence of larval competition on Brazilian Wolbachia-infected Aedes aegypti mosquitoes. Parasit Vectors 2016; 9:282. [PMID: 27183820 PMCID: PMC4869337 DOI: 10.1186/s13071-016-1559-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 05/02/2016] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND With field releases starting in Brazil, particular interest must be given to understanding how the endosymbiotic bacterium Wolbachia pipientis affects Aedes aegypti mosquitoes with a Brazilian genetic background. Currently, there is limited information on how the bacterium affects phenotypic traits such as larval development rate, metabolic reserves and morphometric parameters in Ae. aegypti. Here, we analyze for the first time, the effect of Wolbachia on these key phenotypes and consider how this might impact the potential of the bacterium as a disease control agent in Brazil. METHODS We examined the influence of the wMel strain of Wolbachia in laboratory Ae. aegypti with a Brazilian genetic background, reared under different larval densities. Pupae formation was counted daily to assess differences in development rates. Levels of metabolic reserves and morphometric parameters were assessed in adults resulting from each larval condition. RESULTS wMel infection led to more rapid larval development at higher densities for both males and females, with no effect under less crowded conditions in females. Infection also led to reduced body size at both high and low density, but not at intermediate density, although the scale of this difference was maintained regardless of larval density, in comparison to uninfected individuals. Wing shape also varied significantly between infected and uninfected mosquitoes due to larval density. Glycogen levels in uninfected mosquitoes decreased under higher larval density, but were consistently high with Wolbachia infection, regardless of larval density. CONCLUSIONS We demonstrate that the wMel Wolbachia strain can positively influence some important host fitness traits, and that this interaction is directly linked to the conditions in which the host is reared. Combined with previously published data, these results suggest that this Wolbachia strain could be successfully used as part of the Eliminate Dengue Program in Brazil.
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Affiliation(s)
- Heverton Leandro Carneiro Dutra
- Mosquitos Vetores: Endossimbiontes e Interação Patógeno-Vetor, Centro de Pesquisas René Rachou - Fiocruz, Belo Horizonte, MG, Brazil
| | - Vanessa Lopes da Silva
- Laboratório de Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Mariana da Rocha Fernandes
- Laboratório de Sanidade Animal, Laboratório de Química e Função de Proteínas e Peptídeos e Unidade de Experimentação Animal - RJ, UENF, Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Carlos Logullo
- Laboratório de Sanidade Animal, Laboratório de Química e Função de Proteínas e Peptídeos e Unidade de Experimentação Animal - RJ, UENF, Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Rafael Maciel-de-Freitas
- Laboratório de Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Luciano Andrade Moreira
- Mosquitos Vetores: Endossimbiontes e Interação Patógeno-Vetor, Centro de Pesquisas René Rachou - Fiocruz, Belo Horizonte, MG, Brazil.
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Caragata EP, Dutra HL, Moreira LA. Exploiting Intimate Relationships: Controlling Mosquito-Transmitted Disease with Wolbachia. Trends Parasitol 2016; 32:207-218. [DOI: 10.1016/j.pt.2015.10.011] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 12/15/2022]
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Joubert DA, Walker T, Carrington LB, De Bruyne JT, Kien DHT, Hoang NLT, Chau NVV, Iturbe-Ormaetxe I, Simmons CP, O’Neill SL. Establishment of a Wolbachia Superinfection in Aedes aegypti Mosquitoes as a Potential Approach for Future Resistance Management. PLoS Pathog 2016; 12:e1005434. [PMID: 26891349 PMCID: PMC4758728 DOI: 10.1371/journal.ppat.1005434] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 01/11/2016] [Indexed: 12/20/2022] Open
Abstract
Wolbachia pipientis is an endosymbiotic bacterium estimated to chronically infect between 40-75% of all arthropod species. Aedes aegypti, the principle mosquito vector of dengue virus (DENV), is not a natural host of Wolbachia. The transinfection of Wolbachia strains such as wAlbB, wMel and wMelPop-CLA into Ae. aegypti has been shown to significantly reduce the vector competence of this mosquito for a range of human pathogens in the laboratory. This has led to wMel-transinfected Ae. aegypti currently being released in five countries to evaluate its effectiveness to control dengue disease in human populations. Here we describe the generation of a superinfected Ae. aegypti mosquito line simultaneously infected with two avirulent Wolbachia strains, wMel and wAlbB. The line carries a high overall Wolbachia density and tissue localisation of the individual strains is very similar to each respective single infected parental line. The superinfected line induces unidirectional cytoplasmic incompatibility (CI) when crossed to each single infected parental line, suggesting that the superinfection would have the capacity to replace either of the single constituent infections already present in a mosquito population. No significant differences in fitness parameters were observed between the superinfected line and the parental lines under the experimental conditions tested. Finally, the superinfected line blocks DENV replication more efficiently than the single wMel strain when challenged with blood meals from viremic dengue patients. These results suggest that the deployment of superinfections could be used to replace single infections and may represent an effective strategy to help manage potential resistance by DENV to field deployments of single infected strains.
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Affiliation(s)
- D. Albert Joubert
- School of Biological Sciences, Monash University, Clayton, Melbourne, Victoria, Australia
| | - Thomas Walker
- School of Biological Sciences, Monash University, Clayton, Melbourne, Victoria, Australia
| | - Lauren B. Carrington
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute, Parkville, Melbourne, Victoria, Australia
| | | | - Duong Hue T. Kien
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Nhat Le Thanh Hoang
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | - Iñaki Iturbe-Ormaetxe
- School of Biological Sciences, Monash University, Clayton, Melbourne, Victoria, Australia
| | - Cameron P. Simmons
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute, Parkville, Melbourne, Victoria, Australia
- * E-mail: (CPS); (SLO)
| | - Scott L. O’Neill
- School of Biological Sciences, Monash University, Clayton, Melbourne, Victoria, Australia
- * E-mail: (CPS); (SLO)
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Tantowijoyo W, Arguni E, Johnson P, Budiwati N, Nurhayati PI, Fitriana I, Wardana S, Ardiansyah H, Turley AP, Ryan P, O'Neill SL, Hoffmann AA. Spatial and Temporal Variation in Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Numbers in the Yogyakarta Area of Java, Indonesia, With Implications for Wolbachia Releases. JOURNAL OF MEDICAL ENTOMOLOGY 2016; 53:188-98. [PMID: 26576934 DOI: 10.1093/jme/tjv180] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
of mosquito vector populations, particularly through Wolbachia endosymbionts. The success of these strategies depends on understanding the dynamics of vector populations. In preparation for Wolbachia releases around Yogyakarta, we have studied Aedes populations in five hamlets. Adult monitoring with BioGent- Sentinel (BG-S) traps indicated that hamlet populations had different dynamics across the year; while there was an increase in Aedes aegypti (L.) and Aedes albopictus (Skuse) numbers in the wet season, species abundance remained relatively stable in some hamlets but changed markedly (>2 fold) in others. Local rainfall a month prior to monitoring partly predicted numbers of Ae. aegypti but not Ae. albopictus. Site differences in population size indicated by BG-S traps were also evident in ovitrap data. Egg or larval collections with ovitraps repeated at the same location suggested spatial autocorrelation (<250 m) in the areas of the hamlets where Ae. aegypti numbers were high. Overall, there was a weak negative association (r<0.43) between Ae. aegypti and Ae. albopictus numbers in ovitraps when averaged across collections. Ae. albopictus numbers in ovitraps and BG-S traps were positively correlated with vegetation around areas where traps were placed, while Ae. aegypti were negatively correlated with this feature. These data inform intervention strategies by defining periods when mosquito densities are high, highlighting the importance of local site characteristics on populations, and suggesting relatively weak interactions between Ae. aegypti and Ae. albopictus. They also indicate local areas within hamlets where consistently high mosquito densities may influence Wolbachia invasions and other interventions.
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Rašić G, Endersby-Harshman N, Tantowijoyo W, Goundar A, White V, Yang Q, Filipović I, Johnson P, Hoffmann AA, Arguni E. Aedes aegypti has spatially structured and seasonally stable populations in Yogyakarta, Indonesia. Parasit Vectors 2015; 8:610. [PMID: 26627473 PMCID: PMC4666043 DOI: 10.1186/s13071-015-1230-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 11/23/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Dengue fever, the most prevalent global arboviral disease, represents an important public health problem in Indonesia. Control of dengue relies on the control of its main vector, the mosquito Aedes aegypti, yet nothing is known about the population history and genetic structure of this insect in Indonesia. Our aim was to assess the spatio-temporal population genetic structure of Ae. aegypti in Yogyakarta, a densely populated region on Java with common dengue outbreaks. METHODS We used multiple marker systems (microsatellites, nuclear and mitochondrial genome-wide single nucleotide polymorphisms generated via Restriction-site Associated DNA sequencing) to analyze 979 Ae. aegypti individuals collected from the Yogyakarta city and the surrounding hamlets during the wet season in 2011 and the following dry season in 2012. We employed individual- and group-based approaches for inferring genetic structure. RESULTS We found that Ae. aegypti in Yogyakarta has spatially structured and seasonally stable populations. The spatial structuring was significant for the nuclear and mitochondrial markers, while the temporal structuring was non-significant. Nuclear markers identified three main genetic clusters, showing that hamlets have greater genetic isolation from each other and from the inner city sites. However, one hamlet experienced unrestricted mosquito interbreeding with the inner city, forming a single genetic cluster. Genetic distance was poorly correlated with the spatial distance among mosquito samples, suggesting stronger influence of human-assisted gene flow than active mosquito movement on spatial genetic structure. A star-shaped mitochondrial haplotype network and a significant R(2) test statistic (R(2) = 0.0187, P = 0.001) support the hypothesis that Ae. aegypti in Yogyakarta originated from a small or homogeneous source and has undergone a relatively recent demographic expansion. CONCLUSION We report the first insights into the spatio-temporal genetic structure and the underlying processes in the dengue fever mosquito from Yogyakarta, Indonesia. Our results provide valuable information on the effectiveness of local control measures as well as guidelines for the implementation of novel biocontrol strategies such as release of Wolbachia-infected mosquitoes.
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Affiliation(s)
- Gordana Rašić
- School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Nancy Endersby-Harshman
- School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Warsito Tantowijoyo
- Eliminate Dengue Project-Yogyakarta, Center for Tropical Medicine, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.
| | - Anjali Goundar
- School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Vanessa White
- School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Qiong Yang
- School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Igor Filipović
- School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Petrina Johnson
- Eliminate Dengue Project, School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia.
| | - Ary A Hoffmann
- School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Eggi Arguni
- Eliminate Dengue Project-Yogyakarta, Center for Tropical Medicine, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.
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Nguyen TH, Nguyen HL, Nguyen TY, Vu SN, Tran ND, Le TN, Vien QM, Bui TC, Le HT, Kutcher S, Hurst TP, Duong TTH, Jeffery JAL, Darbro JM, Kay BH, Iturbe-Ormaetxe I, Popovici J, Montgomery BL, Turley AP, Zigterman F, Cook H, Cook PE, Johnson PH, Ryan PA, Paton CJ, Ritchie SA, Simmons CP, O'Neill SL, Hoffmann AA. Field evaluation of the establishment potential of wMelPop Wolbachia in Australia and Vietnam for dengue control. Parasit Vectors 2015; 8:563. [PMID: 26510523 PMCID: PMC4625535 DOI: 10.1186/s13071-015-1174-x] [Citation(s) in RCA: 155] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 10/19/2015] [Indexed: 12/18/2022] Open
Abstract
Background Introduced Wolbachia bacteria can influence the susceptibility of Aedes aegypti mosquitoes to arboviral infections as well as having detrimental effects on host fitness. Previous field trials demonstrated that the wMel strain of Wolbachia effectively and durably invades Ae. aegypti populations. Here we report on trials of a second strain, wMelPop-PGYP Wolbachia, in field sites in northern Australia (Machans Beach and Babinda) and central Vietnam (Tri Nguyen, Hon Mieu Island), each with contrasting natural Ae. aegypti densities. Methods Mosquitoes were released at the adult or pupal stages for different lengths of time at the sites depending on changes in Wolbachia frequency as assessed through PCR assays of material collected through Biogents-Sentinel (BG-S) traps and ovitraps. Adult numbers were also monitored through BG-S traps. Changes in Wolbachia frequency were compared across hamlets or house blocks. Results Releases of adult wMelPop-Ae. aegypti resulted in the transient invasion of wMelPop in all three field sites. Invasion at the Australian sites was heterogeneous, reflecting a slower rate of invasion in locations where background mosquito numbers were high. In contrast, invasion across Tri Nguyen was relatively uniform. After cessation of releases, the frequency of wMelPop declined in all sites, most rapidly in Babinda and Tri Nguyen. Within Machans Beach the rate of decrease varied among areas, and wMelPop was detected for several months in an area with a relatively low mosquito density. Conclusions These findings highlight challenges associated with releasing Wolbachia-Ae. aegypti combinations with low fitness, albeit strong virus interference properties, as a means of sustainable control of dengue virus transmission. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-1174-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tran Hien Nguyen
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam.
| | - H Le Nguyen
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam.
| | - Thu Yen Nguyen
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam.
| | - Sinh Nam Vu
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam.
| | - Nhu Duong Tran
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam.
| | - T N Le
- Institute Pasteur, Nha Trang, Viet Nam.
| | | | - T C Bui
- Institute Pasteur, Nha Trang, Viet Nam.
| | - Huu Tho Le
- Khanh Hoa Health Department, Nha Trang, Viet Nam.
| | - Simon Kutcher
- Australian Foundation for Peoples of Asia and the Pacific Limited, Hanoi, Viet Nam.
| | - Tim P Hurst
- Australian Foundation for Peoples of Asia and the Pacific Limited, Hanoi, Viet Nam.
| | - T T H Duong
- Australian Foundation for Peoples of Asia and the Pacific Limited, Hanoi, Viet Nam.
| | | | | | - B H Kay
- QIMR Berghofer Medical Research Institute, Herston, Australia.
| | | | - Jean Popovici
- School of Biological Sciences, Monash University, Melbourne, Australia.
| | | | - Andrew P Turley
- School of Biological Sciences, Monash University, Melbourne, Australia.
| | - Flora Zigterman
- School of Biological Sciences, Monash University, Melbourne, Australia.
| | - Helen Cook
- School of Biological Sciences, Monash University, Melbourne, Australia.
| | - Peter E Cook
- School of Biological Sciences, Monash University, Melbourne, Australia.
| | - Petrina H Johnson
- School of Biological Sciences, Monash University, Melbourne, Australia.
| | - Peter A Ryan
- School of Biological Sciences, Monash University, Melbourne, Australia.
| | - Chris J Paton
- School of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Smithfield, Australia.
| | - Scott A Ritchie
- School of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Smithfield, Australia.
| | - Cameron P Simmons
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Viet Nam. .,Centre for Tropical Medicine, University of Oxford, Churchill Hospital, Oxford, UK. .,Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia.
| | - Scott L O'Neill
- School of Biological Sciences, Monash University, Melbourne, Australia.
| | - Ary A Hoffmann
- Bio21 Institute and School of BioSciences, University of Melbourne, Parkville, Australia.
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Rašić G, Schama R, Powell R, Maciel-de Freitas R, Endersby-Harshman NM, Filipović I, Sylvestre G, Máspero RC, Hoffmann AA. Contrasting genetic structure between mitochondrial and nuclear markers in the dengue fever mosquito from Rio de Janeiro: implications for vector control. Evol Appl 2015; 8:901-15. [PMID: 26495042 PMCID: PMC4610386 DOI: 10.1111/eva.12301] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Accepted: 07/24/2015] [Indexed: 12/16/2022] Open
Abstract
Dengue is the most prevalent global arboviral disease that affects over 300 million people every year. Brazil has the highest number of dengue cases in the world, with the most severe epidemics in the city of Rio de Janeiro (Rio). The effective control of dengue is critically dependent on the knowledge of population genetic structuring in the primary dengue vector, the mosquito Aedes aegypti. We analyzed mitochondrial and nuclear genomewide single nucleotide polymorphism markers generated via Restriction-site Associated DNA sequencing, as well as traditional microsatellite markers in Ae. aegypti from Rio. We found four divergent mitochondrial lineages and a strong spatial structuring of mitochondrial variation, in contrast to the overall nuclear homogeneity across Rio. Despite a low overall differentiation in the nuclear genome, we detected strong spatial structure for variation in over 20 genes that have a significantly altered expression in response to insecticides, xenobiotics, and pathogens, including the novel biocontrol agent Wolbachia. Our results indicate that high genetic diversity, spatially unconstrained admixing likely mediated by male dispersal, along with locally heterogeneous genetic variation that could affect insecticide resistance and mosquito vectorial capacity, set limits to the effectiveness of measures to control dengue fever in Rio.
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Affiliation(s)
- Gordana Rašić
- Pest and Environmental Adaptation Research Group, School of Biosciences, Bio21 Institute, The University of MelbourneParkville, Vic., Australia
| | - Renata Schama
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, FiocruzRio de Janeiro, Brazil
- Laboratório de Biologia Computacional e Sistemas, Instituto Oswaldo Cruz, FiocruzRio de Janeiro, Brazil
| | - Rosanna Powell
- Pest and Environmental Adaptation Research Group, School of Biosciences, Bio21 Institute, The University of MelbourneParkville, Vic., Australia
| | - Rafael Maciel-de Freitas
- Laboratório de Transmissores de Hematozoários, Instituto Oswaldo Cruz, FiocruzRio de Janeiro, Brazil
| | - Nancy M Endersby-Harshman
- Pest and Environmental Adaptation Research Group, School of Biosciences, Bio21 Institute, The University of MelbourneParkville, Vic., Australia
| | - Igor Filipović
- Pest and Environmental Adaptation Research Group, School of Biosciences, Bio21 Institute, The University of MelbourneParkville, Vic., Australia
| | - Gabriel Sylvestre
- Laboratório de Transmissores de Hematozoários, Instituto Oswaldo Cruz, FiocruzRio de Janeiro, Brazil
| | - Renato C Máspero
- Gerencia de Risco Biológico da Coordenação de Vigilância Ambiental em Saude, Superintendência de Vigilânciaem Saude – SMSRio de Janeiro, Brazil
| | - Ary A Hoffmann
- Pest and Environmental Adaptation Research Group, School of Biosciences, Bio21 Institute, The University of MelbourneParkville, Vic., Australia
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Hoffmann AA, Ross PA, Rašić G. Wolbachia strains for disease control: ecological and evolutionary considerations. Evol Appl 2015; 8:751-68. [PMID: 26366194 PMCID: PMC4561566 DOI: 10.1111/eva.12286] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 06/02/2015] [Indexed: 12/15/2022] Open
Abstract
Wolbachia are endosymbionts found in many insects with the potential to suppress vectorborne diseases, particularly through interfering with pathogen transmission. Wolbachia strains are highly variable in their effects on hosts, raising the issue of which attributes should be selected to ensure that the best strains are developed for disease control. This depends on their ability to suppress viral transmission, invade host populations, persist without loss of viral suppression and not interfere with other control strategies. The potential to achieve these objectives is likely to involve evolutionary constraints; viral suppression may be limited by the ability of infections to spread due to deleterious host fitness effects. However, there are exceptions to these patterns in both natural infections and in novel associations generated following interspecific transfer, suggesting that pathogen blockage, deleterious fitness effects and changes to reproductive biology might be at least partly decoupled to achieve ideal infection attributes. The stability of introduced Wolbachia and its effects on viral transmission remain unclear, but rapid evolutionary changes seem unlikely. Although deliberate transfers of Wolbachia across species remain particularly challenging, the availability of strains with desirable attributes should be expanded, taking advantage of the diversity available across thousands of strains in natural populations.
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Affiliation(s)
- Ary A Hoffmann
- Pest and Environmental Adaptation Research Group, School of BioSciences, Bio21 Institute, The University of Melbourne Parkville, Vic., Australia
| | - Perran A Ross
- Pest and Environmental Adaptation Research Group, School of BioSciences, Bio21 Institute, The University of Melbourne Parkville, Vic., Australia
| | - Gordana Rašić
- Pest and Environmental Adaptation Research Group, School of BioSciences, Bio21 Institute, The University of Melbourne Parkville, Vic., Australia
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Dutra HLC, dos Santos LMB, Caragata EP, Silva JBL, Villela DAM, Maciel-de-Freitas R, Moreira LA. From lab to field: the influence of urban landscapes on the invasive potential of Wolbachia in Brazilian Aedes aegypti mosquitoes. PLoS Negl Trop Dis 2015; 9:e0003689. [PMID: 25905888 PMCID: PMC4408005 DOI: 10.1371/journal.pntd.0003689] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/09/2015] [Indexed: 11/26/2022] Open
Abstract
Background The symbiotic bacterium Wolbachia is currently being trialled as a biocontrol agent in several countries to reduce dengue transmission. Wolbachia can invade and spread to infect all individuals within wild mosquito populations, but requires a high rate of maternal transmission, strong cytoplasmic incompatibility and low fitness costs in the host in order to do so. Additionally, extensive differences in climate, field-release protocols, urbanization level and human density amongst the sites where this bacterium has been deployed have limited comparison and analysis of Wolbachia’s invasive potential. Methodology/Principal Findings We examined key phenotypic effects of the wMel Wolbachia strain in laboratory Aedes aegypti mosquitoes with a Brazilian genetic background to characterize its invasive potential. We show that the wMel strain causes strong cytoplasmic incompatibility, a high rate of maternal transmission and has no evident detrimental effect on host fecundity or fertility. Next, to understand the effects of different urban landscapes on the likelihood of mosquito survival, we performed mark-release-recapture experiments using Wolbachia-uninfected Brazilian mosquitoes in two areas of Rio de Janeiro where Wolbachia will be deployed in the future. We characterized the mosquito populations in relation to the socio-demographic conditions at these sites, and at three other future release areas. We then constructed mathematical models using both the laboratory and field data, and used these to describe the influence of urban environmental conditions on the likelihood that the Wolbachia infection frequency could reach 100% following mosquito release. We predict successful invasion at all five field sites, however the conditions by which this occurs vary greatly between sites, and are strongly influenced by the size of the local mosquito population. Conclusions/Significance Through analysis of laboratory, field and mathematical data, we show that the wMel strain of Wolbachia possesses the characteristics required to spread effectively in different urban socio-demographic environments in Rio de Janeiro, including those where mosquito releases from the Eliminate Dengue Program will take place. Wolbachia are maternally inherited bacterial endosymbionts that induce cytoplasmic incompatibility in mosquitoes, and use this pattern of sterility to facilitate their spread into naïve, uninfected host populations. These bacteria were recently introduced into Aedes aegypti, a species naturally free of Wolbachia, and the primary vector of dengue virus. Wolbachia are currently being used as a biological tool to control dengue transmission in many countries, including Brazil. We performed a series of laboratory and field assays and then created mathematical models in order to understand the invasive ability of the wMel Wolbachia strain in Brazilian Ae. aegypti mosquito populations. We show that wMel infection had no detrimental fitness effects on its new Brazilian host, and would theoretically be able to successfully invade the mosquito populations in the five distinct urban landscapes that we studied. We found that Wolbachia spread more easily where the local mosquito population was smaller. The size of the local human population did not overtly influence the likelihood of spread. These findings provide insight into how the nature of different urban landscapes will affect the likelihood of Wolbachia spreading effectively, which will greatly assist future releases of Wolbachia-infected mosquitoes in Brazil as part of the Eliminate Dengue Program.
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Affiliation(s)
- Heverton Leandro Carneiro Dutra
- Mosquitos Vetores: Endossimbiontes e Interação Patógeno Vetor, Centro de Pesquisas René Rachou—Fiocruz, Belo Horizonte, Minas Gerais, Brazil
| | | | - Eric Pearce Caragata
- Mosquitos Vetores: Endossimbiontes e Interação Patógeno Vetor, Centro de Pesquisas René Rachou—Fiocruz, Belo Horizonte, Minas Gerais, Brazil
| | - Jéssica Barreto Lopes Silva
- Mosquitos Vetores: Endossimbiontes e Interação Patógeno Vetor, Centro de Pesquisas René Rachou—Fiocruz, Belo Horizonte, Minas Gerais, Brazil
| | | | - Rafael Maciel-de-Freitas
- Laboratório de Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luciano Andrade Moreira
- Mosquitos Vetores: Endossimbiontes e Interação Patógeno Vetor, Centro de Pesquisas René Rachou—Fiocruz, Belo Horizonte, Minas Gerais, Brazil
- * E-mail:
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