1
|
Miranda LS, Rudd SR, Mena O, Hudspeth PE, Barboza-Corona JE, Park HW, Bideshi DK. The Perpetual Vector Mosquito Threat and Its Eco-Friendly Nemeses. BIOLOGY 2024; 13:182. [PMID: 38534451 DOI: 10.3390/biology13030182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 03/28/2024]
Abstract
Mosquitoes are the most notorious arthropod vectors of viral and parasitic diseases for which approximately half the world's population, ~4,000,000,000, is at risk. Integrated pest management programs (IPMPs) have achieved some success in mitigating the regional transmission and persistence of these diseases. However, as many vector-borne diseases remain pervasive, it is obvious that IPMP successes have not been absolute in eradicating the threat imposed by mosquitoes. Moreover, the expanding mosquito geographic ranges caused by factors related to climate change and globalization (travel, trade, and migration), and the evolution of resistance to synthetic pesticides, present ongoing challenges to reducing or eliminating the local and global burden of these diseases, especially in economically and medically disadvantaged societies. Abatement strategies include the control of vector populations with synthetic pesticides and eco-friendly technologies. These "green" technologies include SIT, IIT, RIDL, CRISPR/Cas9 gene drive, and biological control that specifically targets the aquatic larval stages of mosquitoes. Regarding the latter, the most effective continues to be the widespread use of Lysinibacillus sphaericus (Ls) and Bacillus thuringiensis subsp. israelensis (Bti). Here, we present a review of the health issues elicited by vector mosquitoes, control strategies, and lastly, focus on the biology of Ls and Bti, with an emphasis on the latter, to which no resistance has been observed in the field.
Collapse
Affiliation(s)
- Leticia Silva Miranda
- Graduate Program in Biomedical Sciences, Department of Biological Sciences, California Baptist University, Riverside, CA 92504, USA
| | - Sarah Renee Rudd
- Graduate Program in Biomedical Sciences, Department of Biological Sciences, California Baptist University, Riverside, CA 92504, USA
- Integrated Biomedical Graduate Studies, and School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Oscar Mena
- Undergraduate Program in Biomedical Sciences, Department of Biological Sciences, California Baptist University, Riverside, CA 92504, USA
| | - Piper Eden Hudspeth
- Undergraduate Program in Biomedical Sciences, Department of Biological Sciences, California Baptist University, Riverside, CA 92504, USA
| | - José E Barboza-Corona
- Departmento de Alimentos, Posgrado en Biociencias, Universidad de Guanajuato Campus Irapuato-Salamanca, Irapuato 36500, Guanajuato, Mexico
| | - Hyun-Woo Park
- Graduate Program in Biomedical Sciences, Department of Biological Sciences, California Baptist University, Riverside, CA 92504, USA
- Undergraduate Program in Biomedical Sciences, Department of Biological Sciences, California Baptist University, Riverside, CA 92504, USA
| | - Dennis Ken Bideshi
- Graduate Program in Biomedical Sciences, Department of Biological Sciences, California Baptist University, Riverside, CA 92504, USA
- Undergraduate Program in Biomedical Sciences, Department of Biological Sciences, California Baptist University, Riverside, CA 92504, USA
| |
Collapse
|
2
|
Ioannou CS, Savvidou EC, Apocha L, Terblanche JS, Papadopoulos NT. Insecticide resistant mosquitoes remain thermal stress resistant, without loss of thermal plasticity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169443. [PMID: 38114031 DOI: 10.1016/j.scitotenv.2023.169443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/07/2023] [Accepted: 12/15/2023] [Indexed: 12/21/2023]
Abstract
A major component of mosquito's climate change response is their heat tolerance, and any ability to rapidly adjust to extreme environmental conditions through phenotypic plasticity. The excessive use of insecticides for the control of major mosquito species leads to resistant populations, however it is largely unclear if this concurrently impacts thermal stress resistance and their potential to adjust tolerance via phenotypic plasticity. Culex pipiens pipiens, Culex pipiens molestus and Aedes albopictus populations obtained from the same region were subjected for 12 generations to selection trials to larvicides Diflubenzuron (DFB) and Bacillus thuringiensis subsp. israelensis (Bti) to develop insecticide resistance. Adults emerging from the selected populations were acclimated at different temperatures and the upper and lower critical thermal limits (CTmax and CTmin) were estimated using dynamic thermal assays. In addition, the supercooling points (SCPs) of non-acclimated adults of resistant and control populations were determined. Our results revealed marked differences in thermal response among the three species, the different acclimation regimes and sexes. Aedes albopictus was more resistant in high than low temperatures compared to both Culex pipiens biotypes. Culex forms responded similarly to heat but differently to cold stress. In both forms, females responded better than males to all thermal stressors. Acclimation at higher and lower temperatures improves CTmax and CTmin values, respectively in both insecticide resistant and control populations of all three species. Overall, selection to insecticides did not affect the thermal performance of adults. Hence, insecticide-resistant mosquito populations perform similarly to untreated ones and are capable of readily adapting to new environmental changes rising concerns regarding their geographic range expansion and disease transmission globally.
Collapse
Affiliation(s)
- Charalampos S Ioannou
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Greece
| | - Eleni C Savvidou
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Greece
| | - Lemonia Apocha
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Greece
| | - John S Terblanche
- Centre for Invasion Biology, Department of Conservation Ecology & Entomology, Stellenbosch University, South Africa
| | - Nikos T Papadopoulos
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Greece.
| |
Collapse
|
3
|
Huang L, Han G, Crickmore N, Li C, Xia Y, Song F, Xu J. Characterization of a novel cell wall hydrolase CwlE involved in Bacillus thuringiensis subsp . israelensis mother cell lysis. Front Microbiol 2023; 14:1250542. [PMID: 37829449 PMCID: PMC10565116 DOI: 10.3389/fmicb.2023.1250542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/15/2023] [Indexed: 10/14/2023] Open
Abstract
Cell wall hydrolases are ubiquitous among spore-form bacteria and essential for mother cell lysis. In this study, a novel cell wall hydrolase gene cwlE involved in mother cell lysis was characterized from Bacillus thuringiensis subsp. israelensis (Bti) strain Bt-59. cwlE was specifically expressed in Bti and located in the large plasmid carrying the insecticidal genes. The encoded CwlE protein consists of a MurNAc-LAA domain and two highly conserved catalytic residues (E26 and E151). The recombinant CwlE-His protein was able to digest the cell wall of Bti, indicating that CwlE is an N-acetylmuramoyl-L-alanine amidase. Transcriptional analysis indicated that cwlE began to express at the early stage of stationary phase and was controlled by SigE. Single mutation of cwlE gene delayed Bti mother cell lysis, while double mutation of cwlE and sigK completely blocked Bti mother cell lysis. After exposure to UV light to deactivate the crystal proteins, the level of decrease of insecticidal activity against mosquito larvae of Bt-59 (ΔcwlE-sigK) was less than that observed for Bt-59. This study elucidates the mechanism of Bti mother cell lysis and provides an effective strategy for mosquito control using Bt products with increased persistence.
Collapse
Affiliation(s)
- Lixin Huang
- Department of Applied Microbiology, Lixiahe District Institute of Agricultural Sciences in Jiangsu/National Agricultural Experimental Station for Agricultural Microbiology in Yangzhou, Yangzhou, China
| | - Guangjie Han
- Department of Applied Microbiology, Lixiahe District Institute of Agricultural Sciences in Jiangsu/National Agricultural Experimental Station for Agricultural Microbiology in Yangzhou, Yangzhou, China
| | - Neil Crickmore
- Department of Biochemistry, School of Biological Sciences, University of Sussex, Brighton, United Kingdom
| | - Chuanming Li
- Department of Applied Microbiology, Lixiahe District Institute of Agricultural Sciences in Jiangsu/National Agricultural Experimental Station for Agricultural Microbiology in Yangzhou, Yangzhou, China
| | - Yang Xia
- Department of Applied Microbiology, Lixiahe District Institute of Agricultural Sciences in Jiangsu/National Agricultural Experimental Station for Agricultural Microbiology in Yangzhou, Yangzhou, China
| | - Fuping Song
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jian Xu
- Department of Applied Microbiology, Lixiahe District Institute of Agricultural Sciences in Jiangsu/National Agricultural Experimental Station for Agricultural Microbiology in Yangzhou, Yangzhou, China
| |
Collapse
|
4
|
Ridha MR, Marlinae L, Zubaidah T, Fadillah NA, Widjaja J, Rosadi D, Rahayu N, Ningsih M, Desimal I, Sofyandi A. Control methods for invasive mosquitoes of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in Indonesia. Vet World 2023; 16:1952-1963. [PMID: 37859959 PMCID: PMC10583872 DOI: 10.14202/vetworld.2023.1952-1963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 08/30/2023] [Indexed: 10/21/2023] Open
Abstract
The two invasive mosquito species in Indonesia are Aedes aegypti and Ae. albopictus. These mosquitoes are a serious nuisance to humans and are also the primary vectors of several foreign pathogens, such as dengue, Zika, and chikungunya viruses. Efforts must be made to reduce the possibility of mosquito bites and the potential for disease transmission. Given the invasion of these two Aedes species, this approach should be considered as part of an integrated strategy to manage them. This review discusses existing and developing control techniques for invasive Ae. aegypti and Ae. albopictus, with an emphasis on those that have been and are being used in Indonesia. Environmental, mechanical, biological (e.g., Bacillus thuringiensis and Wolbachia), and chemical (e.g., insect growth regulators and pyrethroids) approaches are discussed in this review, considering their effectiveness, sustainability, and control methods.
Collapse
Affiliation(s)
- Muhammad Rasyid Ridha
- Vector-borne and Zoonotic Diseases Research Group, Research Center for Public Health and Nutrition, Cibinong Science Center, National Research and Innovation Agency, Jl. Raya Jakarta-Bogor KM.46, Bogor, West Java, 16915, Indonesia
| | - Lenie Marlinae
- Department of Environmental Health, Public Health Study Program, Medical Faculty, Universitas Labung Mangkurat, Jl. A. Yani, Km. 36 Banjarbaru, South Kalimantan, Indonesia
| | - Tien Zubaidah
- Environmental Health Program, Banjarmasin Health Polytechnic, Jl. H. Mistar Cokrokusumo No.1A, Kemuning, Banjar Baru, South Kalimantan, 70714, Indonesia
| | - Noor Ahda Fadillah
- Department of Epidemiology, Public Health Study Program, Medical Faculty, Universitas Labung Mangkurat, Jl. A. Yani, Km. 36 Banjarbaru, South Kalimantan, Indonesia
| | - Junus Widjaja
- Vector-borne and Zoonotic Diseases Research Group, Research Center for Public Health and Nutrition, Cibinong Science Center, National Research and Innovation Agency, Jl. Raya Jakarta-Bogor KM.46, Bogor, West Java, 16915, Indonesia
| | - Dian Rosadi
- Department of Epidemiology, Public Health Study Program, Medical Faculty, Universitas Labung Mangkurat, Jl. A. Yani, Km. 36 Banjarbaru, South Kalimantan, Indonesia
| | - Nita Rahayu
- Vector-borne and Zoonotic Diseases Research Group, Research Center for Public Health and Nutrition, Cibinong Science Center, National Research and Innovation Agency, Jl. Raya Jakarta-Bogor KM.46, Bogor, West Java, 16915, Indonesia
| | - Murtiana Ningsih
- Public Health Study Program, Sports Sciences and Public Health Faculty, Universitas Pendidikan Mataram, Jl. Pemuda No. 59 A Mataram West Nusa Tenggara, Indonesia
| | - Iwan Desimal
- Public Health Study Program, Sports Sciences and Public Health Faculty, Universitas Pendidikan Mataram, Jl. Pemuda No. 59 A Mataram West Nusa Tenggara, Indonesia
| | - Arif Sofyandi
- Public Health Study Program, Sports Sciences and Public Health Faculty, Universitas Pendidikan Mataram, Jl. Pemuda No. 59 A Mataram West Nusa Tenggara, Indonesia
| |
Collapse
|
5
|
Engdahl CS, Caragata EP, Tavadia M, Dimopoulos G. Chromobacterium Biopesticide Exposure Does Not Select for Resistance in Aedes Mosquitoes. mBio 2023; 14:e0048023. [PMID: 37017525 PMCID: PMC10127667 DOI: 10.1128/mbio.00480-23] [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: 02/26/2023] [Accepted: 03/06/2023] [Indexed: 04/06/2023] Open
Abstract
Developing effective tools to control mosquito populations is essential for reducing the incidence of diseases like malaria and dengue. Biopesticides of microbial origin are a rich, underexplored source of mosquitocidal compounds. We previously developed a biopesticide from the bacterium Chromobacterium sp. Panama that rapidly kills vector mosquito larvae, including Aedes aegypti and Anopheles gambiae. Here, we demonstrate that two independent Ae. aegypti colonies exposed to a sublethal dose of that biopesticide over consecutive generations persistently exhibited high mortality and developmental delays, indicating that resistance did not develop during the study period. Critically, the descendants of biopesticide-exposed mosquitoes experienced decreased longevity and did not display increased susceptibility to dengue virus or decreased susceptibility to common chemical insecticides. Through RNA sequencing, we observed no link between biopesticide exposure and the increased activity of xenobiotic metabolism and detoxification genes typically associated with insecticide resistance. These findings indicate that the Chromobacterium biopesticide is an exciting, emerging mosquito control tool. IMPORTANCE Vector control is an essential part of mitigating diseases caused by pathogens that mosquitoes spread. Modern vector control is highly reliant on using synthetic insecticides to eliminate mosquito populations before they can cause disease. However, many of these populations have become resistant to commonly used insecticides. There is a strong need to explore alternative vector control strategies that aim to mitigate disease burden. Biopesticides, insecticides of biological origin, can have unique mosquitocidal activities, meaning they can effectively kill mosquitoes that are already resistant to other insecticides. We previously developed a highly effective mosquito biopesticide from the bacterium Chromobacterium sp. Csp_P. Here, we investigate whether exposure to a sublethal dose of this Csp_P biopesticide over 9 to 10 generations causes resistance to arise in Aedes aegypti mosquitoes. We find no evidence of resistance at the physiological or molecular levels, confirming that the Csp_P biopesticide is a highly promising new tool for controlling mosquito populations.
Collapse
Affiliation(s)
- Cecilia Springer Engdahl
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Eric P. Caragata
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
- Florida Medical Entomology Laboratory, Department of Entomology & Nematology, Institute of Food & Agricultural Sciences, University of Florida, Vero Beach, Florida, USA
| | - Mihra Tavadia
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| |
Collapse
|
6
|
MosChito rafts as effective and eco-friendly tool for the delivery of a Bacillus thuringiensis-based insecticide to Aedes albopictus larvae. Sci Rep 2023; 13:3041. [PMID: 36810640 PMCID: PMC9944263 DOI: 10.1038/s41598-023-29501-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 02/06/2023] [Indexed: 02/23/2023] Open
Abstract
Adult mosquito females, through their bites, are responsible for the transmission of different zoonotic pathogens. Although adult control represents a pillar for the prevention of disease spread, larval control is also crucial. Herein we characterized the effectiveness of a suitable tool, named "MosChito raft", for the aquatic delivery of a Bacillus thuringiensis var. israelensis (Bti) formulate, a bioinsecticide active by ingestion against mosquito larvae. MosChito raft is a floating tool composed by chitosan cross-linked with genipin in which a Bti-based formulate and an attractant have been included. MosChito rafts (i) resulted attractive for the larvae of the Asian tiger mosquito Aedes albopictus, (ii) induced larval mortality within a few hours of exposure and, more importantly, (iii) protected the Bti-based formulate, whose insecticidal activity was maintained for more than one month in comparison to the few days residual activity of the commercial product. The delivery method was effective in both laboratory and semi-field conditions, demonstrating that MosChito rafts may represent an original, eco-based and user-friendly solution for larval control in domestic and peri-domestic aquatic habitats such as saucers and artificial containers in residential or urban environments.
Collapse
|
7
|
Aromatic Residues on the Side Surface of Cry4Ba-Domain II of Bacillus thuringiensis subsp. israelensis Function in Binding to Their Counterpart Residues on the Aedes aegypti Alkaline Phosphatase Receptor. Toxins (Basel) 2023; 15:toxins15020114. [PMID: 36828427 PMCID: PMC9960242 DOI: 10.3390/toxins15020114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/22/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023] Open
Abstract
Receptor binding is a prerequisite process to exert the mosquitocidal activity of the Cry4Ba toxin of Bacillus thuringiensis subsp. israelensis. The beta-sheet prism (domain II) and beta-sheet sandwich (domain III) of the Cry4Ba toxin have been implicated in receptor binding, albeit the precise binding mechanisms of these remain unclear. In this work, alanine scanning was used to determine the contribution to receptor binding of some aromatic and hydrophobic residues on the surface of domains II and III that are predicted to be responsible for binding to the Aedes aegypti membrane-bound alkaline phosphatase (Aa-mALP) receptor. Larvicidal activity assays against A. aegypti larvae revealed that aromatic residues (Trp327 on the β2 strand, Tyr347 on the β3-β4 loop, and Tyr359 on the β4 strand) of domain II were important to the toxicity of the Cry4Ba toxin. Quantitative binding assays using enzyme-linked immunosorbent assay (ELISA) showed similar decreasing trends in binding to the Aa-mALP receptor and in toxicity of the Cry4Ba mutants Trp327Ala, Tyr347Ala, and Tyr359Ala, suggesting that a possible function of these surface-exposed aromatic residues is receptor binding. In addition, binding assays of the Cry4Ba toxin to the mutants of the binding residues Gly513, Ser490, and Phe497 of the Aa-mALP receptor supported the binding function of Trp327, Tyr347, and Tyr359 of the Cry4Ba toxin, respectively. Altogether, our results showed for the first time that aromatic residues on a side surface of the Cry4Ba domain II function in receptor binding. This finding provides greater insight into the possible molecular mechanisms of the Cry4Ba toxin.
Collapse
|
8
|
Ogunlade ST, Meehan MT, Adekunle AI, McBryde ES. A Systematic Review of Mathematical Models of Dengue Transmission and Vector Control: 2010-2020. Viruses 2023; 15:254. [PMID: 36680294 PMCID: PMC9862433 DOI: 10.3390/v15010254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/19/2023] Open
Abstract
Vector control methods are considered effective in averting dengue transmission. However, several factors may modify their impact. Of these controls, chemical methods, in the long run, may increase mosquitoes' resistance to chemicides, thereby decreasing control efficacy. The biological methods, which may be self-sustaining and very effective, could be hampered by seasonality or heatwaves (resulting in, e.g., loss of Wolbachia infection). The environmental methods that could be more effective than the chemical methods are under-investigated. In this study, a systematic review is conducted to explore the present understanding of the effectiveness of vector control approaches via dengue transmission models.
Collapse
Affiliation(s)
- Samson T. Ogunlade
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia
- College of Medicine and Dentistry, James Cook University, Townsville 4811, Australia
| | - Michael T. Meehan
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia
| | - Adeshina I. Adekunle
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia
- Defence Science and Technology Group, Department of Defence, Melbourne 3207, Australia
| | - Emma S. McBryde
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia
| |
Collapse
|
9
|
Carvalho KS, Rezende TMT, Romão TP, Rezende AM, Chiñas M, Guedes DRD, Paiva-Cavalcanti M, Silva-Filha MHNL. Aedes aegypti Strain Subjected to Long-Term Exposure to Bacillus thuringiensis svar. israelensis Larvicides Displays an Altered Transcriptional Response to Zika Virus Infection. Viruses 2022; 15:72. [PMID: 36680112 PMCID: PMC9866606 DOI: 10.3390/v15010072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/13/2022] [Accepted: 12/21/2022] [Indexed: 12/29/2022] Open
Abstract
Bacillus thuringiensis svar. israelensis (Bti) larvicides are effective in controlling Aedes aegypti; however, the effects of long-term exposure need to be properly evaluated. We established an Ae. aegypti strain that has been treated with Bti for 30 generations (RecBti) and is still susceptible to Bti, but females exhibited increased susceptibility to Zika virus (ZIKV). This study compared the RecBti strain to a reference strain regarding: first, the relative transcription of selected immune genes in ZIKV-challenged females (F30) with increased susceptibility detected in a previous study; then, the whole transcriptomic profile using unchallenged females (F35). Among the genes compared by RT-qPCR in the ZIKV-infected and uninfected females from RecBti (F30) and the reference strain, hop, domeless, relish 1, defensin A, cecropin D, and gambicin showed a trend of repression in RecBti infected females. The transcriptome of RecBti (F35) unchallenged females, compared with a reference strain by RNA-seq, showed a similar profile and only 59 differentially expressed genes were found among 9202 genes analyzed. Our dataset showed that the long-term Bti exposure of the RecBti strain was associated with an alteration of the expression of genes potentially involved in the response to ZIKV infection in challenged females, which is an important feature found under this condition.
Collapse
Affiliation(s)
- Karine S. Carvalho
- Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife 50670-420, Brazil
| | | | - Tatiany P. Romão
- Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife 50670-420, Brazil
| | - Antônio M. Rezende
- Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife 50670-420, Brazil
| | - Marcos Chiñas
- Center for Genomic Sciences, National Autonomous University of Mexico, Cuernavaca 62210, Mexico
| | | | | | | |
Collapse
|
10
|
Engdahl CS, Tikhe CV, Dimopoulos G. Discovery of novel natural products for mosquito control. Parasit Vectors 2022; 15:481. [PMID: 36539851 PMCID: PMC9768913 DOI: 10.1186/s13071-022-05594-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 11/17/2022] [Indexed: 12/24/2022] Open
Abstract
Vector control plays a key role in reducing the public health burden of mosquito-borne diseases. Today's vector control strategies largely rely on synthetic insecticides that can have a negative environmental impact when applied outdoors and often become inefficient because of the mosquitoes' ability to develop resistance. An alternative and promising approach to circumvent these challenges involves the implementation of insecticides derived from nature (biopesticides) for vector control. Biopesticides can constitute naturally occurring organisms or substances derived from them that have lifespan-shortening effects on disease vectors such as mosquitoes. Here we present the discovery and evaluation of natural product-based biological control agents that can potentially be developed into biopesticides for mosquito control. We screened a natural product collection comprising 390 compounds and initially identified 26 molecules with potential ability to kill the larval stages of the yellow fever mosquito Aedes aegypti, which is responsible for transmitting viruses such as dengue, Zika, chikungunya and yellow fever. Natural products identified as hits in the screen were further evaluated for their suitability for biopesticide development. We show that a selection of the natural product top hits, bactobolin, maytansine and ossamycin, also killed the larval stages of the malaria-transmitting mosquito Anopheles gambiae as well as the adult form of both species. We have further explored the usefulness of crude extracts and preparations from two of the best candidates' sources (organisms of origin) for mosquitocidal activity, that is extracts from the two bacteria Burkholderia thailandensis and Streptomyces hygroscopicus var. ossamyceticus.
Collapse
Affiliation(s)
- Cecilia S. Engdahl
- grid.21107.350000 0001 2171 9311W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD USA ,grid.12650.300000 0001 1034 3451Present Address: Department of Clinical Microbiology, Virology, Umeå University, 90185 Umeå, Sweden
| | - Chinmay V. Tikhe
- grid.21107.350000 0001 2171 9311W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD USA
| | - George Dimopoulos
- grid.21107.350000 0001 2171 9311W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD USA
| |
Collapse
|
11
|
Nair K, Al-Thani R, Jaoua S. Bacillus thuringiensis strain QBT220 pBtoxis plasmid structural instability enhances δ-endotoxins synthesis and bioinsecticidal activity. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 228:112975. [PMID: 34773843 DOI: 10.1016/j.ecoenv.2021.112975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/20/2021] [Accepted: 11/05/2021] [Indexed: 06/13/2023]
Abstract
Bacillus thuringiensis subsp. israelensis (Bti) spherical parasporal crystal contains several insecticidal proteins used as environmentally safe alternative to toxic chemical pesticides. The exploration of a Bti strain isolated from Qatar QBT220 genes encoding the δ-endotoxins responsible of the insecticidal activities revealed the alteration of a 14-kb DNA region including the δ-endotoxins cry10A and cyt1C genes of pBtoxis plasmid. The presence of all the insecticidal genes except cry10A and cyt1C was explained by a structural instability of the plasmid pBtoxis. However, when compared with the Bti reference strains H14 and QBT217 that carry all δ-endotoxins coding genes, it was found that QBT220, has a significantly higher insecticidal activity against the dipteran insect Aedes aegypti larvae despite of the plasmid pBtoxis structural instability due to the alteration of cry10A and cyt1C genes. In addition, QBT220 showed the highest δ-endotoxin synthesis per spore, compared with that of the wildtype strains. These findings confirm that the altered genes cry10A and cyt1C are not mandatory for Bti insecticidal activities and on the other hand show a possible inhibitory effect played by the 2 proteins Cry10A and Cyt1C on the insecticidal activities of the other insecticidal proteins. In addition, the QBT220 increased δ-endotoxins synthesis per cell, makes this strain a good candidate for possible applications in the industrial production of bioinsecticides.
Collapse
Affiliation(s)
- Kavita Nair
- Environmental Science Program, Department of Biological & Environmental Sciences, College of Arts & Sciences, Qatar University, 2713, Doha, Qatar
| | - Roda Al-Thani
- Environmental Science Program, Department of Biological & Environmental Sciences, College of Arts & Sciences, Qatar University, 2713, Doha, Qatar
| | - Samir Jaoua
- Environmental Science Program, Department of Biological & Environmental Sciences, College of Arts & Sciences, Qatar University, 2713, Doha, Qatar.
| |
Collapse
|
12
|
Ioannou CS, Hadjichristodoulou C, Mouchtouri VA, Papadopoulos NT. Effects of Selection to Diflubenzuron and Bacillus thuringiensis Var. Israelensis on the Overwintering Successes of Aedes albopictus (Diptera: Culicidae). INSECTS 2021; 12:822. [PMID: 34564261 PMCID: PMC8471009 DOI: 10.3390/insects12090822] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/05/2021] [Accepted: 09/08/2021] [Indexed: 11/25/2022]
Abstract
Aedes albopictus is an invasive mosquito species responsible for local transmission of chikungunya and dengue viruses in Europe. In the absence of available treatments, insecticides-based control remains one of the most important viable strategies to prevent emerging problems. Diflubenzuron (DFB) and Bacillus thuringiensis var. israelensis (Bti) are among the most commonly used larvicides for Ae. albopictus control with consequent concerns for the potential development of resistance. Studies on the resistance emergence in Ae. albopictus and its persistence in the wild to both DFB and Bti are essential for the efficient and sustainable planning of the control programmes. In this context, larvae from a recently laboratory established population were subjected to increasing selective pressure for nine successive generations using both DFB and Bti. The resistance levels and the overwintering success of the selected populations relative to control (colonies that received no selection) were determined. Results revealed an 8.5- and 1.6-fold increase on the resistance levels following selection with DFB and Bti, respectively. The selection process to both larvicides had no apparent impacts on the overwintering capability relative to control, suggesting the successful persistence of the selected individuals in the wild on an annual base.
Collapse
Affiliation(s)
- Charalampos S. Ioannou
- Laboratory of Hygiene & Epidemiology, Faculty of Medicine, School of Health Science, University of Thessaly, 41222 Larissa, Greece; (C.S.I.); (C.H.); (V.A.M.)
- Laboratory of Entomology & Agricultural Zoology, Department of Agriculture Crop. Production and Rural Environment, School of Agricultural Sciences, University of Thessaly, 38446 Volos, Greece
| | - Christos Hadjichristodoulou
- Laboratory of Hygiene & Epidemiology, Faculty of Medicine, School of Health Science, University of Thessaly, 41222 Larissa, Greece; (C.S.I.); (C.H.); (V.A.M.)
| | - Varvara A. Mouchtouri
- Laboratory of Hygiene & Epidemiology, Faculty of Medicine, School of Health Science, University of Thessaly, 41222 Larissa, Greece; (C.S.I.); (C.H.); (V.A.M.)
| | - Nikos T. Papadopoulos
- Laboratory of Entomology & Agricultural Zoology, Department of Agriculture Crop. Production and Rural Environment, School of Agricultural Sciences, University of Thessaly, 38446 Volos, Greece
| |
Collapse
|
13
|
Carvalho KDS, Guedes DRD, Crespo MM, de Melo-Santos MAV, Silva-Filha MHNL. Aedes aegypti continuously exposed to Bacillus thuringiensis svar. israelensis does not exhibit changes in life traits but displays increased susceptibility for Zika virus. Parasit Vectors 2021; 14:379. [PMID: 34321098 PMCID: PMC8317411 DOI: 10.1186/s13071-021-04880-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 07/16/2021] [Indexed: 11/20/2022] Open
Abstract
Background Aedes aegypti can transmit arboviruses worldwide, and Bacillus thuringiensis svar. israelensis (Bti)-based larvicides represent an effective tool for controlling this species. The safety of Bti and lack of resistance have been widely reported; however, little is known regarding the impact of the extensive use of these larvicides on the life traits of mosquitoes. Therefore, this study investigated biological parameters, including susceptibility to arbovirus, of an Ae. aegypti strain (RecBti) subjected to 29 generations of exposure to Bti compared with the RecL reference strain. Methods The biological parameters of individuals reared under controlled conditions were compared. Also, the viral susceptibility of females not exposed to Bti during their larval stage was analysed by oral infection and followed until 14 or 21 days post-infection (dpi). Results RecBti individuals did not display alterations in the traits that were assessed (fecundity, fertility, pupal weight, developmental time, emergence rate, sex ratio and haematophagic capacity) compared to RecL individuals. Females from both strains were susceptible to dengue serotype 2 (DENV-2) and Zika virus (ZIKV). However, RecBti females showed significantly higher rates of ZIKV infection compared with RecL females at 7 (90% versus 68%, Chi-square: χ2 = 7.27, df = 1, P = 0.006) and 14 dpi (100% versus 87%, Chi-square: χ2 = 7.69, df = 1, P = 0.005) and for dissemination at 7 dpi (83.3% versus 36%, Fisher’s exact test: P < 0.0001, OR = 0.11, 95% CI 0.03–0.32). Quantification of DENV-2 and ZIKV viral particles produced statistically similar results for females from both strains. Conclusions Prolonged exposure of Ae. aegypti larvae to Bti did not alter most of the evaluated biological parameters, except that RecBti females exhibited a higher vector susceptibility for ZIKV. This finding is related to a background of Bti exposure for several generations but not to a previous exposure of the tested females during the larval stage. This study highlights mosquito responses that could be associated with the chronic exposure to Bti in addition to the primary larvicidal effect elicited by this control agent. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04880-6.
Collapse
Affiliation(s)
| | | | - Mônica Maria Crespo
- Department of Entomology, Instituto Aggeu Magalhães-Fiocruz, Recife, Pernambuco, Brazil
| | | | | |
Collapse
|
14
|
Bacterial Toxins Active against Mosquitoes: Mode of Action and Resistance. Toxins (Basel) 2021; 13:toxins13080523. [PMID: 34437394 PMCID: PMC8402332 DOI: 10.3390/toxins13080523] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/18/2021] [Accepted: 06/19/2021] [Indexed: 12/25/2022] Open
Abstract
Larvicides based on the bacteria Bacillus thuringiensis svar. israelensis (Bti) and Lysinibacillus sphaericus are effective and environmentally safe compounds for the control of dipteran insects of medical importance. They produce crystals that display specific and potent insecticidal activity against larvae. Bti crystals are composed of multiple protoxins: three from the three-domain Cry type family, which bind to different cell receptors in the midgut, and one cytolytic (Cyt1Aa) protoxin that can insert itself into the cell membrane and act as surrogate receptor of the Cry toxins. Together, those toxins display a complex mode of action that shows a low risk of resistance selection. L. sphaericus crystals contain one major binary toxin that display an outstanding persistence in field conditions, which is superior to Bti. However, the action of the Bin toxin based on its interaction with a single receptor is vulnerable for resistance selection in insects. In this review we present the most recent data on the mode of action and synergism of these toxins, resistance issues, and examples of their use worldwide. Data reported in recent years improved our understanding of the mechanism of action of these toxins, showed that their combined use can enhance their activity and counteract resistance, and reinforced their relevance for mosquito control programs in the future years.
Collapse
|
15
|
Short-Term Selection to Diflubenzuron and Bacillus thuringiensis Var. Israelensis Differentially Affects the Winter Survival of Culex pipiens f. Pipiens and Culex pipiens f. Molestus (Diptera: Culicidae). INSECTS 2021; 12:insects12060527. [PMID: 34204105 PMCID: PMC8228153 DOI: 10.3390/insects12060527] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/20/2021] [Accepted: 06/03/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary In Europe, Culex pipiens (Diptera: Culicidae) mosquito, the prime vector of West Nile virus, consists of two forms, named pipiens and molestus, that exhibit substantial differences in their biology, including overwintering behavior. Diflubenzuron (DFB) and Bacillus thuringiensis var. israelensis (Bti) are among the most widely used larvicides which pose major concerns for resistance development. In temperate areas, winter represents a very challenging period for the survival of many insects, including mosquitoes, and therefore potential fitness costs associated with insecticide selection may reduce their overwintering success. In this context, we investigated how short-term selection of Cx. pipiens f. pipiens and molestus forms to DFB and Bti affect their overwintering success. Our findings revealed that selection to both larvicides induced a high fitness cost in terms of reduced winter survival of Cx. pipiens f. molestus but not of pipiens form, suggesting potential differences in the persistence of the selected individuals in the wild from year to year. Abstract The Culex pipiens (Diptera: Culicidae) mosquito is of high medical importance as it is considered the prime vector of West Nile virus. In Europe, this species consists of two forms, named pipiens and molestus, that exhibit substantial differences in their overwintering biology. Diflubenzuron (DFB) and Bacillus thuringiensis var. israelensis (Bti) are two of the most used larvicides in mosquito control, including that of Culex pipiens. The high dependency on these two larvicides poses major concerns for resistance development. The evolution and stability of resistance to insecticides has been associated with fitness costs that may be manifested under stressful conditions, such as the winter period. This study investigated how short-term selection of pipiens and molestus forms to both larvicides affect their overwintering success. Larvae from each form were subjected to the same selective pressure (80% mortality) for three successive generations with DFB and Bti. At the end of this process, the winter survival between the selected populations and the controls (colonies without selection) was determined for each form. Selection to both larvicides significantly reduced the winter survival rates of molestus but not of pipiens form, indicating potential differences in the persistence of the selected individuals from year to year between the two forms.
Collapse
|
16
|
Rossi da Silva K, Ribeiro da Silva W, Silva BP, Arcos AN, da Silva Ferreira FA, Soares-da-Silva J, Pontes GO, Roque RA, Tadei WP, Navarro-Silva MA, Zequi JAC. New traps for the capture of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) (Diptera: Culicidae) eggs and adults. PLoS Negl Trop Dis 2021; 15:e0008813. [PMID: 33861744 PMCID: PMC8081340 DOI: 10.1371/journal.pntd.0008813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 04/28/2021] [Accepted: 03/04/2021] [Indexed: 11/19/2022] Open
Abstract
The control of arboviruses carried by Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) can be performed with tools that monitor and reduce the circulation of these vectors. Therefore, the efficiency of four types of traps in capturing A. aegypti and A. albopictus eggs and adults, with the biological product Vectobac WG, was evaluated in the field. For this, 20 traps were installed in two locations, which were in the South (Londrina, Paraná) and North (Manaus, Amazonas) Regions of Brazil, from March to April 2017 and January to February 2018, respectively. The UELtrap-E (standard trap) and UELtrap-EA traps captured A. aegypti and A. albopictus eggs: 1703/1866 eggs in Londrina, and 10268/2149 eggs in Manaus, respectively, and presented high ovitraps positivity index (OPI) values (averages: 100%/100% in Londrina, and 100%/96% in Manaus, respectively); and high egg density index (EDI) values (averages: 68/75 in Londrina, and 411/89 in Manaus, respectively), so they had statistically superior efficiency to that of the CRtrap-E and CRtrap-EA traps in both regions, that captured less eggs and adults: 96/69 eggs in Londrina, and 1091/510 eggs in Manaus, respectively. Also presented lower OPI values (averages: 28%/4% in Londrina, and 88%/60% in Manaus, respectively); and lower EDI values (averages: 10.5/9 in Londrina, and 47/30 in Manaus, respectively). The capture ratios of Aedes adults in the UELtrap-EA and CRtrap-EA traps in Londrina and Manaus were 53.3%/29.5% and 0%/9.8%, respectively. UELtrap-EA can be adopted as efficient tool for Aedes monitoring due to their high sensitivity, low cost and ease of use.
Collapse
Affiliation(s)
- Karina Rossi da Silva
- Laboratório de Entomologia Médica, Departamento de Biologia Animal e Vegetal, Universidade Estadual de Londrina (UEL), Programa de Pós-Graduação em Ciências Biológicas, Londrina, Paraná, Brasil
| | - William Ribeiro da Silva
- Programa de Pós-Graduação em Ciências Biológicas (Entomologia), Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas, Brasil
- Laboratório de Controle Biológico e Biotecnologia da Malária e Dengue, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brasil
| | - Bianca Piraccini Silva
- Laboratório de Entomologia Médica, Departamento de Biologia Animal e Vegetal, Universidade Estadual de Londrina (UEL), Programa de Pós-Graduação em Ciências Biológicas, Londrina, Paraná, Brasil
| | - Adriano Nobre Arcos
- Laboratório de Controle Biológico e Biotecnologia da Malária e Dengue, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brasil
- Programa de Pós-Graduação em Ecologia e Conservação, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, Mato Grosso do Sul, Brasil
| | - Francisco Augusto da Silva Ferreira
- Programa de Pós-Graduação em Ciências Biológicas (Entomologia), Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas, Brasil
- Laboratório de Controle Biológico e Biotecnologia da Malária e Dengue, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brasil
| | - Joelma Soares-da-Silva
- Curso de Ciências Naturais, Campus VII, Universidade Federal do Maranhão (UFMA), Codó, Maranhão, Brasil
| | - Grafe Oliveira Pontes
- Laboratório de Controle Biológico e Biotecnologia da Malária e Dengue, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brasil
- Centro de Entomologia, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT–HVD), Manaus, Amazonas, Brasil
| | - Rosemary Aparecida Roque
- Centro de Entomologia, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT–HVD), Manaus, Amazonas, Brasil
| | - Wanderli Pedro Tadei
- Programa de Pós-Graduação em Ciências Biológicas (Entomologia), Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas, Brasil
- Centro de Entomologia, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT–HVD), Manaus, Amazonas, Brasil
| | - Mário Antonio Navarro-Silva
- Laboratório de Morfologia e Fisiologia de Culicidae e Chironomidae, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, Brasil
| | - João Antonio Cyrino Zequi
- Laboratório de Entomologia Médica, Departamento de Biologia Animal e Vegetal, Universidade Estadual de Londrina (UEL), Programa de Pós-Graduação em Ciências Biológicas, Londrina, Paraná, Brasil
| |
Collapse
|
17
|
Liu T, Xie YG, Lin F, Xie LH, Yang WQ, Su XH, Ou CQ, Luo L, Xiao Q, Gan L, Chen XG. A long-lasting biological larvicide against the dengue vector mosquito Aedes albopictus. PEST MANAGEMENT SCIENCE 2021; 77:741-748. [PMID: 32869454 DOI: 10.1002/ps.6069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 08/19/2020] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Aedes albopictus is the primary vector of mosquito-borne diseases, including dengue and chikungunya, in China. The management of vector mosquitoes is the primary strategy for the control of such infectious diseases. The gravid Ae. albopictus prefers to skip-oviposit its eggs into different small water containers, and the management of these breeding places is critical for mosquito control. Bacillus thuringiensis subspecies Israelensis (Bti) is a useful biological larvicide, but the effective period of the currently available commercial product is relatively short. This study aimed to develop a long-lasting formulation of Bti to control the dengue vector mosquito Ae. albopictus. RESULTS Water-soluble polyethylene glycols and water-insoluble hexadecanol were mixed with Bti to develop the long-lasting formulation Bti-BLOCK, based on the solid dispersion technique. The controlled release of Bti-BLOCK and its effect on Ae. albopictus were assayed in the laboratory and in the field. The results showed that Bti toxins were slowly released from Bti-BLOCK into the water and maintained at an effective dose for at least 6 months. Bti-BLOCK caused high mortality during the immature stage (>90%) and achieved full inhibition during pupation (100%). The efficacy lasted at least 12 weeks in the laboratory and 6 weeks in the field. Furthermore, we confirmed an 89% reduction in Ae. albopictus density and a reduction in the R0 of dengue to a low-risk level after 6 months of open-field interventions. CONCLUSIONS We developed a long-lasting biological larvicide, Bti-BLOCK, which displayed very good efficacy in the control of the dengue vector mosquito Ae. albopictus.
Collapse
Affiliation(s)
- Tong Liu
- Department of Pathogen Biology, Key Laboratory of Tropical Disease Research of Guangdong Province, School of Public Health, Southern Medical University, Guangzhou, China
| | - Yu-Gu Xie
- Department of Pathogen Biology, Key Laboratory of Tropical Disease Research of Guangdong Province, School of Public Health, Southern Medical University, Guangzhou, China
| | - Feng Lin
- Department of Pathogen Biology, Key Laboratory of Tropical Disease Research of Guangdong Province, School of Public Health, Southern Medical University, Guangzhou, China
| | - Li-Hua Xie
- Department of Pathogen Biology, Key Laboratory of Tropical Disease Research of Guangdong Province, School of Public Health, Southern Medical University, Guangzhou, China
| | - Wen-Qiang Yang
- Department of Pathogen Biology, Key Laboratory of Tropical Disease Research of Guangdong Province, School of Public Health, Southern Medical University, Guangzhou, China
| | - Xing-Hua Su
- Department of Pathogen Biology, Key Laboratory of Tropical Disease Research of Guangdong Province, School of Public Health, Southern Medical University, Guangzhou, China
| | - Chun-Quan Ou
- State Key Laboratory of Organ Failure Research, Department of Biostatistics, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Lei Luo
- Guangzhou Center for Disease Control and Prevention, Guangzhou, Guangdong, China
| | - Qi Xiao
- Guangdong Huilimin Public Health Institute CO., Ltd, Guangzhou, Guangdong, China
| | - Lu Gan
- Guangdong Huilimin Public Health Institute CO., Ltd, Guangzhou, Guangdong, China
| | - Xiao-Guang Chen
- Department of Pathogen Biology, Key Laboratory of Tropical Disease Research of Guangdong Province, School of Public Health, Southern Medical University, Guangzhou, China
| |
Collapse
|
18
|
Gimnig JE, Ombok M, Bayoh N, Mathias D, Ochomo E, Jany W, Walker ED. Efficacy of extended release formulations of Natular™ (spinosad) against larvae and adults of Anopheles mosquitoes in western Kenya. Malar J 2020; 19:436. [PMID: 33243237 PMCID: PMC7691113 DOI: 10.1186/s12936-020-03507-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/18/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Larval source management is recommended as a supplementary vector control measure for the prevention of malaria. Among the concerns related to larviciding is the feasibility of implementation in tropical areas with large numbers of habitats and the need for frequent application. Formulated products of spinosad that are designed to be effective for several weeks may mitigate some of these concerns. METHODS In a semi-field study, three formulations of spinosad (emulsifiable concentrate, extended release granules and tablet formulations) were tested in naturalistic habitats in comparison to an untreated control. Cohorts of third instar Anopheles gambiae (Diptera: Culicidae) were introduced into the habitats in screened cages every week up to four weeks after application and monitored for survivorship over three days. A small-scale field trial was then conducted in two villages. Two of the spinosad formulations were applied in one village over the course of 18 months. Immature mosquito populations were monitored with standard dippers in sentinel sites and adult populations were monitored by pyrethrum spray catches. RESULTS In the semi-field study, the efficacy of the emulsifiable concentrate of spinosad waned 1 week after treatment. Mortality in habitats treated with the extended release granular formulation of spinosad was initially high but declined gradually over 4 weeks while mortality in habitats treated with the dispersable tablet formulation was low immediately after treatment but rose to 100% through four weeks. In the field study, immature and adult Anopheles mosquito populations were significantly lower in the intervention village compared to the control village during the larviciding period. Numbers of collected mosquitoes were lower in the intervention village compared to the control village during the post-intervention period but the difference was not statistically significant. CONCLUSIONS The extended release granular formulation and the dispersible tablet formulations of spinosad are effective against larval Anopheles mosquitoes for up to four weeks and may be an effective tool as part of larval source management programmes for reducing adult mosquito density and malaria transmission.
Collapse
Affiliation(s)
- John E Gimnig
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Atlanta, GA, USA.
| | - Maurice Ombok
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya
| | - Nabie Bayoh
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya
- PMI VectorLink Project, Abt Associates, Lusaka, Zambia
| | - Derrick Mathias
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Atlanta, GA, USA
- Florida Medical Entomological Laboratory, University of Florida, Vero Beach, FL, USA
| | - Eric Ochomo
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya
| | | | - Edward D Walker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
19
|
Santos VSV, Pereira BB. Low toxicity and high efficacy in use of novel approaches to control Aedes aegypti. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2020; 23:243-254. [PMID: 32515686 DOI: 10.1080/10937404.2020.1776655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Arthropod-borne viruses are a group of etiologic agents accounting for different incapacitating diseases that progress to severe and lethal forms in animal and human targets consequently representing a significant burden on public health and global economies. Although attempts were undertaken to combat Aedes aegypti, the primary urban mosquito vector of several life-threatening diseases, the misuse of chemical pesticides, development of resistance, and toxicity on non-target species still need to be overcome. In this context, it is imperative for development of long-lasting, novel approaches envisioning effective control of Aedes aegypti, mainly in endemic regions. Thus, the present review was undertaken to describe safe and eco-friendly approaches as potential weapons against Aedes aegypti. Accordingly, the findings discussed indicated that biological larvicides and genetic engineering technologies constitute noteworthy alternatives of future mosquito-borne arbovirus disease control efforts.
Collapse
Affiliation(s)
- Vanessa Santana Vieira Santos
- Department of Environmental Health, Laboratory of Environmental Health, Federal University of Uberlândia, Santa Mônica Campus , Uberlândia, Minas Gerais, Brazil
- Department of Biotechnology, Federal University of Uberlândia, Institute of Biotechnology, Umuarama Campus , Uberlândia, Minas Gerais, Brazil
| | - Boscolli Barbosa Pereira
- Department of Environmental Health, Laboratory of Environmental Health, Federal University of Uberlândia, Santa Mônica Campus , Uberlândia, Minas Gerais, Brazil
- Department of Biotechnology, Federal University of Uberlândia, Institute of Biotechnology, Umuarama Campus , Uberlândia, Minas Gerais, Brazil
| |
Collapse
|
20
|
Functional Bacillus thuringiensis Cyt1Aa Is Necessary To Synergize Lysinibacillus sphaericus Binary Toxin (Bin) against Bin-Resistant and -Refractory Mosquito Species. Appl Environ Microbiol 2020; 86:AEM.02770-19. [PMID: 32005737 DOI: 10.1128/aem.02770-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 01/21/2020] [Indexed: 11/20/2022] Open
Abstract
The binary (Bin) toxin from Lysinibacillus sphaericus is effective to mosquito larvae, but its utilization is threatened by the development of insect resistance. Bin toxin is composed of the BinB subunit required for binding to midgut receptors and the BinA subunit that causes toxicity after cell internalization, mediated by BinB. Culex quinquefasciatus resistance to this toxin is caused by mutations that prevent expression of Bin toxin receptors in the midgut. Previously, it was shown that the Cyt1Aa toxin from Bacillus thuringiensis subsp. israelensis restores Bin toxicity to Bin-resistant C. quinquefasciatus and to Aedes aegypti larvae, which are naturally devoid of functional Bin receptors. Our goal was to elucidate the mechanism involved in Cyt1Aa synergism with Bin in such larvae. In vivo assays showed that the mixture of Bin toxin, or its BinA subunit, with Cyt1Aa was effective to kill resistant larvae. However, no specific binding interaction between Cyt1Aa and the Bin toxin, or its subunits, was observed. The synergy between Cyt1Aa and Bin toxins is dependent on functional Cyt1Aa, as demonstrated by using the nontoxic Cyt1AaV122E mutant toxin affected in oligomerization and membrane insertion, which was unable to synergize Bin toxicity in resistant larvae. The synergism correlated with the internalization of Bin or BinA into anterior and medium midgut epithelial cells, which occurred only in larvae treated with wild-type Cyt1Aa toxin. This toxin is able to overcome failures in the binding step involving BinB receptor by allowing the internalization of Bin toxin, or its BinA subunit, into the midgut cells.IMPORTANCE One promising management strategy for mosquito control is the utilization of a mixture of L. sphaericus and B. thuringiensis subsp. israelensis insecticidal toxins. From this set, Bin and Cyt1Aa toxins synergize and display toxicity to resistant C. quinquefasciatus and to A. aegypti larvae, whose midgut cells lack Bin toxin receptors. Our data set provides evidence that functional Cyt1Aa is essential for internalization of Bin or its BinA subunit into such cells, but binding interaction between Bin and Cyt1Aa is not observed. Thus, this mechanism contrasts with that for the synergy between Cyt1Aa and the B. thuringiensis subsp. israelensis Cry toxins, where active Cyt1Aa is not necessary but a specific binding between Cry and Cyt1Aa is required. Our study established the initial molecular basis of the synergy between Bin and Cyt1Aa, and these findings enlarge our knowledge of their mode of action, which could help to develop improved strategies to cope with insect resistance.
Collapse
|