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Rique HL, Menezes HSG, Melo-Santos MAV, Silva-Filha MHNL. Evaluation of a long-lasting microbial larvicide against Culex quinquefasciatus and Aedes aegypti under laboratory and a semi-field trial. Parasit Vectors 2024; 17:391. [PMID: 39272177 PMCID: PMC11401406 DOI: 10.1186/s13071-024-06465-5] [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: 04/30/2024] [Accepted: 08/22/2024] [Indexed: 09/15/2024] Open
Abstract
BACKGROUND Microbial larvicides containing both LysiniBacillus sphaericus and Bacillus thuringiensis svar. israelensis (Bti) insecticidal crystals can display advantages for mosquito control. This includes a broader action against larvae that are refractory to the Binary (Bin) toxin from L. sphaericus, as Bin-resistant Culex quinquefasciatus and Aedes aegypti naturally refractory larvae, which often co-habit urban areas of endemic countries for arboviruses. Our principal goal was to assess the toxicity of a combined L. sphaericus/Bti larvicide (Vectomax FG™) to Cx. quinquefasciatus (susceptible CqS and Bin-resistant CqR) and Ae. aegypti (Rocke) and to determine its persistence in the breeding sites with those larvae. METHODS The toxicity of a combined L. sphaericus/Bti product (VectoMax FG™) to larvae was performed using bioassays, and persistence was evaluated in simulate field trials carried out under the shade, testing two label concentrations during 12 weeks. A laboratory strain SREC, established with CqS and CqR larvae, was kept during four generations to evaluate the ability of the L. sphaericus/Bti to eliminate resistant larvae. RESULTS The L. sphaericus/Bti showed toxicity (mg/L) to larvae from all strains with a decreasing pattern for CqS (LC50 = 0.006, LC90 = 0.030), CqR (LC50 = 0.009, LC90 = 0.069), and Rocke (LC50 = 0.042, LC90 = 0.086). In a simulated field trial, the larvicide showed a persistence of 6 weeks and 8 weeks, controlling larvae from all strains in containers with 100 L of water, using 2 g or 4 g per container (100 L), respectively. The treatment of SREC larvae with L. sphaericus/Bti showed its capacity to eliminate the Bin-resistant individuals using suitable concentrations to target those larvae. CONCLUSIONS Our results showed the high efficacy and persistence of the L. sphaericus/Bti larvicide to control Cx. quinquefasciatus and Ae. aegypti that might cohabit breeding sites. These findings demonstrated that such larvicides can be an effective tool for controlling those species in urban areas with a low potential for selecting resistance.
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Affiliation(s)
- Hyago Luiz Rique
- Departament of Entomology, Instituto Aggeu Magalhães-Fiocruz, Av. Moraes Rego S/N, Recife, PE, 50740-465, Brazil
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Deng SQ, Li N, Yang XK, Lu HZ, Liu JH, Peng ZY, Wang LM, Zhang M, Zhang C, Chen C. Recombinant Beauveria bassiana expressing Bacillus thuringiensis toxin Cyt1Aa: a promising approach for enhancing Aedes mosquito control. Microbiol Spectr 2024; 12:e0379223. [PMID: 38809029 PMCID: PMC11218515 DOI: 10.1128/spectrum.03792-23] [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: 10/28/2023] [Accepted: 04/20/2024] [Indexed: 05/30/2024] Open
Abstract
The entomopathogenic fungus Beauveria bassiana provides an eco-friendly substitute to chemical insecticides for mosquito control. Nevertheless, its widespread application has been hindered by its comparatively slow efficacy in eliminating mosquitoes. To augment the potency of B. bassiana against Aedes mosquitoes, a novel recombinant strain, Bb-Cyt1Aa, was developed by incorporating the Bacillus thuringiensis toxin gene Cyt1Aa into B. bassiana. The virulence of Bb-Cyt1Aa was evaluated against Aedes aegypti and Aedes albopictus using insect bioassays. Compared to the wild-type (WT) strain, the median lethal time (LT50) for A. aegypti larvae infected with Bb-Cyt1Aa decreased by 33.3% at a concentration of 1 × 108 conidia/mL and by 22.2% at 1 × 107 conidia/mL. The LT50 for A. aegypti adults infected with Bb-Cyt1Aa through conidia ingestion was reduced by 37.5% at 1 × 108 conidia/mL and by 33.3% at 1 × 107 conidia/mL. Likewise, the LT50 for A. aegypti adults infected with Bb-Cyt1Aa through cuticle contact decreased by 33.3% and 30.8% at the same concentrations, respectively. Furthermore, the Bb-Cyt1Aa strain also demonstrated increased toxicity against both larval and adult A. albopictus, when compared to the WT strain. In conclusion, our study demonstrated that the expression of B. thuringiensis toxin Cyt1Aa in B. bassiana enhanced its virulence against Aedes mosquitoes. This suggests that B. bassiana expressing Cyt1Aa has potential value for use in mosquito control. IMPORTANCE Beauveria bassiana is a naturally occurring fungus that can be utilized as a bioinsecticide against mosquitoes. Cyt1Aa is a delta-endotoxin protein produced by Bacillus thuringiensis that exhibits specific and potent insecticidal activity against mosquitoes. In our study, the expression of this toxin Cyt1Aa in B. bassiana enhances the virulence of B. bassiana against Aedes aegypti and Aedes albopictus, thereby increasing their effectiveness in killing mosquitoes. This novel strain can be used alongside chemical insecticides to reduce dependence on harmful chemicals, thereby minimizing negative impacts on the environment and human health. Additionally, the potential resistance of B. bassiana against mosquitoes in the future could be overcome by acquiring novel combinations of exogenous toxin genes. The presence of B. bassiana that expresses Cyt1Aa is of significant importance in mosquito control as it enhances genetic diversity, creates novel virulent strains, and contributes to the development of safer and more sustainable methods of mosquito control.
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Affiliation(s)
- Sheng-Qun Deng
- Department of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- Anhui Province Key Laboratory of Zoonoses, the Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, China
| | - Ni Li
- Department of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Xu-Ke Yang
- Department of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- Anhui Province Key Laboratory of Zoonoses, the Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, China
| | - Hong-Zheng Lu
- Department of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Jia-Hua Liu
- Department of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Zhe-Yu Peng
- Department of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Lin-Min Wang
- Department of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Mao Zhang
- Department of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- Anhui Province Key Laboratory of Zoonoses, the Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, China
| | - Chao Zhang
- Department of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- Anhui Province Key Laboratory of Zoonoses, the Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, China
| | - Chen Chen
- Anhui Province Key Laboratory of Zoonoses, the Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, China
- Department of Microbiology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
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Williams AE, Gittis AG, Botello K, Cruz P, Martin-Martin I, Valenzuela Leon PC, Sumner B, Bonilla B, Calvo E. Structural and functional comparisons of salivary α-glucosidases from the mosquito vectors Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2024; 167:104097. [PMID: 38428508 PMCID: PMC10955559 DOI: 10.1016/j.ibmb.2024.104097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/26/2024] [Accepted: 02/26/2024] [Indexed: 03/03/2024]
Abstract
Mosquito vectors of medical importance both blood and sugar feed, and their saliva contains bioactive molecules that aid in both processes. Although it has been shown that the salivary glands of several mosquito species exhibit α-glucosidase activities, the specific enzymes responsible for sugar digestion remain understudied. We therefore expressed and purified three recombinant salivary α-glucosidases from the mosquito vectors Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus and compared their functions and structures. We found that all three enzymes were expressed in the salivary glands of their respective vectors and were secreted into the saliva. The proteins, as well as mosquito salivary gland extracts, exhibited α-glucosidase activity, and the recombinant enzymes displayed preference for sucrose compared to p-nitrophenyl-α-D-glucopyranoside. Finally, we solved the crystal structure of the Ae. aegypti α-glucosidase bound to two calcium ions at a 2.3 Ångstrom resolution. Molecular docking suggested that the Ae. aegypti α-glucosidase preferred di- or polysaccharides compared to monosaccharides, consistent with enzymatic activity assays. Comparing structural models between the three species revealed a high degree of similarity, suggesting similar functional properties. We conclude that the α-glucosidases studied herein are important enzymes for sugar digestion in three mosquito species.
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Affiliation(s)
- Adeline E Williams
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Apostolos G Gittis
- Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Karina Botello
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Phillip Cruz
- Office of Cyber Infrastructure and Computational Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Ines Martin-Martin
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Paola Carolina Valenzuela Leon
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Benjamin Sumner
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Brian Bonilla
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Eric Calvo
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA.
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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.
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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
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Rezende TMT, Menezes HSG, Rezende AM, Cavalcanti MP, Silva YMG, de-Melo-Neto OP, Romão TP, Silva-Filha MHNL. Culex quinquefasciatus Resistant to the Binary Toxin from Lysinibacillus sphaericus Displays a Consistent Downregulation of Pantetheinase Transcripts. Biomolecules 2023; 14:33. [PMID: 38254633 PMCID: PMC10813629 DOI: 10.3390/biom14010033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/07/2023] [Accepted: 12/11/2023] [Indexed: 01/24/2024] Open
Abstract
Culex quinquefasciatus resistance to the binary (Bin) toxin, the major larvicidal component from Lysinibacillus sphaericus, is associated with mutations in the cqm1 gene, encoding the Bin-toxin receptor. Downregulation of the cqm1 transcript was found in the transcriptome of larvae resistant to the L. sphaericus IAB59 strain, which produces both the Bin toxin and a second binary toxin, Cry48Aa/Cry49Aa. Here, we investigated the transcription profiles of two other mosquito colonies having Bin resistance only. These confirmed the cqm1 downregulation and identified transcripts encoding the enzyme pantetheinase as the most downregulated mRNAs in both resistant colonies. Further quantification of these transcripts reinforced their strong downregulation in Bin-resistant larvae. Multiple genes were found encoding this enzyme in Cx. quinquefasciatus and a recombinant pantetheinase was then expressed in Escherichia coli and Sf9 cells, with its presence assessed in the midgut brush border membrane of susceptible larvae. The pantetheinase was expressed as a ~70 kDa protein, potentially membrane-bound, which does not seem to be significantly targeted by glycosylation. This is the first pantetheinase characterization in mosquitoes, and its remarkable downregulation might reflect features impacted by co-selection with the Bin-resistant phenotype or potential roles in the Bin-toxin mode of action that deserve to be investigated.
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Affiliation(s)
- Tatiana M. T. Rezende
- Department of Entomology, Instituto Aggeu Magalhães-Fiocruz, Recife 50740-465, PE, Brazil; (T.M.T.R.); (H.S.G.M.); (Y.M.G.S.); (T.P.R.)
| | - Heverly S. G. Menezes
- Department of Entomology, Instituto Aggeu Magalhães-Fiocruz, Recife 50740-465, PE, Brazil; (T.M.T.R.); (H.S.G.M.); (Y.M.G.S.); (T.P.R.)
| | - Antonio M. Rezende
- Department of Microbiology, Instituto Aggeu Magalhães-Fiocruz, Recife 50740-465, PE, Brazil; (A.M.R.); (M.P.C.); (O.P.d.-M.-N.)
| | - Milena P. Cavalcanti
- Department of Microbiology, Instituto Aggeu Magalhães-Fiocruz, Recife 50740-465, PE, Brazil; (A.M.R.); (M.P.C.); (O.P.d.-M.-N.)
| | - Yuri M. G. Silva
- Department of Entomology, Instituto Aggeu Magalhães-Fiocruz, Recife 50740-465, PE, Brazil; (T.M.T.R.); (H.S.G.M.); (Y.M.G.S.); (T.P.R.)
| | - Osvaldo P. de-Melo-Neto
- Department of Microbiology, Instituto Aggeu Magalhães-Fiocruz, Recife 50740-465, PE, Brazil; (A.M.R.); (M.P.C.); (O.P.d.-M.-N.)
| | - Tatiany P. Romão
- Department of Entomology, Instituto Aggeu Magalhães-Fiocruz, Recife 50740-465, PE, Brazil; (T.M.T.R.); (H.S.G.M.); (Y.M.G.S.); (T.P.R.)
| | - Maria Helena N. L. Silva-Filha
- Department of Entomology, Instituto Aggeu Magalhães-Fiocruz, Recife 50740-465, PE, Brazil; (T.M.T.R.); (H.S.G.M.); (Y.M.G.S.); (T.P.R.)
- National Institute for Molecular Entomology, Rio de Janeiro 21941-902, RJ, Brazil
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Menezes HSG, Costa-Latgé SG, Genta FA, Napoleão TH, Paiva PMG, Romão TP, Silva-Filha MHNL. A Culex quinquefasciatus strain resistant to the binary toxin from Lysinibacillus sphaericus displays altered enzyme activities and energy reserves. Parasit Vectors 2023; 16:273. [PMID: 37559134 PMCID: PMC10413512 DOI: 10.1186/s13071-023-05893-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 07/20/2023] [Indexed: 08/11/2023] Open
Abstract
BACKGROUND The resistance of a Culex quinquefasciatus strain to the binary (Bin) larvicidal toxin from Lysinibacillus sphaericus is due to the lack of expression of the toxin's receptors, the membrane-bound Cqm1 α-glucosidases. A previous transcriptomic profile of the resistant larvae showed differentially expressed genes coding Cqm1, lipases, proteases and other genes involved in lipid and carbohydrate metabolism. This study aimed to investigate the metabolic features of Bin-resistant individuals by comparing the activity of some enzymes, energy reserves, fertility and fecundity to a susceptible strain. METHODS The activity of specific enzymes was recorded in midgut samples from resistant and susceptible larvae. The amount of lipids and reducing sugars was determined for larvae and adults from both strains. Additionally, the fecundity and fertility parameters of these strains under control and stress conditions were examined. RESULTS Enzyme assays showed that the esterase activities in the midgut of resistant larvae were significantly lower than susceptible ones using acetyl-, butyryl- and heptanoyl-methylumbelliferyl esthers as substrates. The α-glucosidase activity was also reduced in resistant larvae using sucrose and a synthetic substrate. No difference in protease activities as trypsins, chymotrypsins and aminopeptidases was detected between resistant and susceptible larvae. In larval and adult stages, the resistant strain showed an altered profile of energy reserves characterized by significantly reduced levels of lipids and a greater amount of reducing sugars. The fertility and fecundity of females were similar for both strains, indicating that those changes in energy reserves did not affect these reproductive parameters. CONCLUSIONS Our dataset showed that Bin-resistant insects display differential metabolic features co-selected with the phenotype of resistance that can potentially have effects on mosquito fitness, in particular, due to the reduced lipid accumulation.
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Affiliation(s)
- Heverly Suzany G Menezes
- Department of Entomology, Instituto Aggeu Magalhães-FIOCRUZ, Av. Moraes Rego s/n, Recife, PE, 50740-465, Brazil
| | - Samara G Costa-Latgé
- Laboratory of Insect Biochemistry and Physiology, Instituto Oswaldo Cruz-FIOCRUZ, Rio de Janeiro, RJ, 21045-900, Brazil
| | - Fernando A Genta
- Laboratory of Insect Biochemistry and Physiology, Instituto Oswaldo Cruz-FIOCRUZ, Rio de Janeiro, RJ, 21045-900, Brazil
- National Institute for Molecular Entomology, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Thiago H Napoleão
- Department of Biochemistry, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil
| | - Patrícia M G Paiva
- Department of Biochemistry, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil
| | - Tatiany P Romão
- Department of Entomology, Instituto Aggeu Magalhães-FIOCRUZ, Av. Moraes Rego s/n, Recife, PE, 50740-465, Brazil
| | - Maria Helena N L Silva-Filha
- Department of Entomology, Instituto Aggeu Magalhães-FIOCRUZ, Av. Moraes Rego s/n, Recife, PE, 50740-465, Brazil.
- National Institute for Molecular Entomology, Rio de Janeiro, RJ, 21941-902, Brazil.
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Lu HZ, Sui Y, Lobo NF, Fouque F, Gao C, Lu S, Lv S, Deng SQ, Wang DQ. Challenge and opportunity for vector control strategies on key mosquito-borne diseases during the COVID-19 pandemic. Front Public Health 2023; 11:1207293. [PMID: 37554733 PMCID: PMC10405932 DOI: 10.3389/fpubh.2023.1207293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 06/29/2023] [Indexed: 08/10/2023] Open
Abstract
Mosquito-borne diseases are major global health problems that threaten nearly half of the world's population. Conflicting resources and infrastructure required by the coronavirus disease 2019 (COVID-19) global pandemic have resulted in the vector control process being more demanding than ever. Although novel vector control paradigms may have been more applicable and efficacious in these challenging settings, there were virtually no reports of novel strategies being developed or implemented during COVID-19 pandemic. Evidence shows that the COVID-19 pandemic has dramatically impacted the implementation of conventional mosquito vector measures. Varying degrees of disruptions in malaria control and insecticide-treated nets (ITNs) and indoor residual spray (IRS) distributions worldwide from 2020 to 2021 were reported. Control measures such as mosquito net distribution and community education were significantly reduced in sub-Saharan countries. The COVID-19 pandemic has provided an opportunity for innovative vector control technologies currently being developed. Releasing sterile or lethal gene-carrying male mosquitoes and novel biopesticides may have advantages that are not matched by traditional vector measures in the current context. Here, we review the effects of COVID-19 pandemic on current vector control measures from 2020 to 2021 and discuss the future direction of vector control, taking into account probable evolving conditions of the COVID-19 pandemic.
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Affiliation(s)
- Hong-Zheng Lu
- Chinese Center for Disease Control and Prevention, National Institute of Parasitic Diseases, Shanghai, China
- Department of Pathogen Biology, the Key Laboratory of Microbiology and Parasitology of Anhui Province, the Key Laboratory of Zoonoses of High Institutions in Anhui, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Yuan Sui
- Brown School, Washington University, St. Louis, MO, United States
| | - Neil F. Lobo
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, San Francisco, CA, United States
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States
| | - Florence Fouque
- Research for Implementation Unit, The Special Programme for Research and Training in Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Chen Gao
- Chinese Center for Disease Control and Prevention, National Institute of Parasitic Diseases, Shanghai, China
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Shenning Lu
- Chinese Center for Disease Control and Prevention, National Institute of Parasitic Diseases, Shanghai, China
- Chinese Center for Tropical Diseases Research, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China
| | - Shan Lv
- Chinese Center for Disease Control and Prevention, National Institute of Parasitic Diseases, Shanghai, China
- Chinese Center for Tropical Diseases Research, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Sheng-Qun Deng
- Department of Pathogen Biology, the Key Laboratory of Microbiology and Parasitology of Anhui Province, the Key Laboratory of Zoonoses of High Institutions in Anhui, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Duo-Quan Wang
- Chinese Center for Disease Control and Prevention, National Institute of Parasitic Diseases, Shanghai, China
- Chinese Center for Tropical Diseases Research, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Best HL, Williamson LJ, Lipka-Lloyd M, Waller-Evans H, Lloyd-Evans E, Rizkallah PJ, Berry C. The Crystal Structure of Bacillus thuringiensis Tpp80Aa1 and Its Interaction with Galactose-Containing Glycolipids. Toxins (Basel) 2022; 14:863. [PMID: 36548760 PMCID: PMC9784298 DOI: 10.3390/toxins14120863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/21/2022] [Accepted: 11/24/2022] [Indexed: 12/13/2022] Open
Abstract
Tpp80Aa1 from Bacillus thuringiensis is a Toxin_10 family protein (Tpp) with reported action against Culex mosquitoes. Here, we demonstrate an expanded target range, showing Tpp80Aa1 is also active against the larvae of Anopheles gambiae and Aedes aegypti mosquitoes. We report the first crystal structure of Tpp80Aa1 at a resolution of 1.8 Å, which shows Tpp80Aa1 consists of two domains: an N-terminal β-trefoil domain resembling a ricin B lectin and a C-terminal putative pore-forming domain sharing structural similarity with the aerolysin family. Similar to other Tpp family members, we observe Tpp80Aa1 binds to the mosquito midgut, specifically the posterior midgut and the gastric caecum. We also identify that Tpp80Aa1 can interact with galactose-containing glycolipids and galactose, and this interaction is critical for exerting full insecticidal action against mosquito target cell lines.
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Affiliation(s)
- Hannah L. Best
- School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3AX, UK
| | | | | | - Helen Waller-Evans
- School of Pharmacy, Cardiff University, Park Place, Cardiff CF10 3AX, UK
| | - Emyr Lloyd-Evans
- School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3AX, UK
| | | | - Colin Berry
- School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3AX, UK
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da Silva JS, Oliveira M, Viana JL, da Silva MC, Pinheiro VCS, Zilse GAC, Tadei WP. Cyt1Aa toxin gene frequency in Bacillus thuringiensis isolates and its relation with pathogenicity for vector mosquitoes. Acta Trop 2022; 233:106549. [PMID: 35671782 DOI: 10.1016/j.actatropica.2022.106549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 11/28/2022]
Abstract
Bacillus thuringiensis produces several virulence factors, the main ones being the Cry and Cyt toxins, present in the parasporal body produced during sporulation. The Cyt toxins have mechanisms specific for mosquitoes and Cyt1Aa, the most studied cytolytic toxin, is effective for mosquito control by acting in synergism with Cry toxins. The goal of the present work was to study the frequency of the codifying gene for Cyt1Aa in B. thuringiensis native isolates acquired from samples of soil, insect and water, as well as to verify any possible genetic polymorphism. 1,448 B. thuringiensis strains were used for DNA extraction and PCR technique, all with the use of a primer that amplifies a fragment of 300 pairs of the cyt1Aa gene. The strains that showed amplification in the PCR reaction were sequenced and compared to each other and to the sequences available at Genbank. 32 (2.3%) strains of B. thuringiensis showed positive amplification for the cyt1Aa gene. The highest frequency of isolates with cyt1Aa gene was acquired from samples coming from the Cerrado biome, both isolates from soil and from insects, equally with 3.4%. The cyt1Aa gene sequencing highlighted that, for that 300 bp region, the gene is conserved and there is no single-base polymorphism.
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Affiliation(s)
- Joelma S da Silva
- Curso Ciências Naturais, Centro de Ciências de Codó, Universidade Federal do Maranhão, Avenida Dr. José Anselmo, 2008, São Sebastião, Codó, Maranhão, 65400-000, Brasil.
| | - Maxcilene Oliveira
- Laboratório de Entomologia Médica, Departamento de Química e Biologia, Centro de Estudos Superiores de Caxias, Universidade Estadual do Maranhão, Praça Duque de Caxias, s/n, Morro do Alecrim, Caxias, Maranhão, 65604-380, Brasil
| | - Juliete L Viana
- Universidade do Estado do Amazonas - UEA, Programa de Pós-graduação em Biodiversidade e Biotecnologia da Rede BIONORTE - PPG BIONORTE, Av. Carvalho Leal, 1777, Ed. Anexo, 4° andar, Cachoeirinha, CEP 69065001, Manaus, AM, Brasil
| | - Maria C da Silva
- Laboratório de Bactérias Entomopatogênicas e Marcadores Moleculares, Departamento de Química e Biologia, Centro de Estudos Superiores de Caxias, Universidade Estadual do Maranhão, Praça Duque de Caxias, s/n, Morro do Alecrim, Caxias, Maranhão, 65604-380, Brasil
| | - Valéria C S Pinheiro
- Laboratório de Entomologia Médica, Departamento de Química e Biologia, Centro de Estudos Superiores de Caxias, Universidade Estadual do Maranhão, Praça Duque de Caxias, s/n, Morro do Alecrim, Caxias, Maranhão, 65604-380, Brasil
| | - Gislene A C Zilse
- Grupo de Pesquisas em Abelhas, Instituto Nacional de Pesquisas da Amazônia, Programa de Pós-Graduação em Entomologia, Avenida André Araújo, 2936, Petrópolis, Manaus, Amazonas, 69067-375, Brasil
| | - Wanderli P Tadei
- Laboratório de Malária e Dengue, Instituto Nacional de Pesquisas da Amazônia, Programa de Pós-Graduação em Entomologia, Avenida André Araújo, 2936, Petrópolis, Manaus, Amazonas, 69067-375, Brasil
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10
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Batool K, Alam I, Liu P, Shu Z, Zhao S, Yang W, Jie X, Gu J, Chen XG. Recombinant Mosquito Densovirus with Bti Toxins Significantly Improves Pathogenicity against Aedes albopictus. Toxins (Basel) 2022; 14:147. [PMID: 35202174 PMCID: PMC8879223 DOI: 10.3390/toxins14020147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/12/2022] [Accepted: 02/14/2022] [Indexed: 12/12/2022] Open
Abstract
Mosquito densoviruses (MDVs) are mosquito-specific viruses that are recommended as mosquito bio-control agents. The MDV Aedes aegypti densovirus (AeDNV) is a good candidate for controlling mosquitoes. However, the slow activity restricts their widespread use for vector control. In this study, we introduced the Bacillus thuringiensis (Bti) toxin Cry11Aa domain II loop α8 and Cyt1Aa loop β6-αE peptides into the AeDNV genome to improve its mosquitocidal efficiency; protein expression was confirmed using nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS). Recombinant plasmids were transfected into mosquito C6/36 cell lines, and the expression of specific peptides was detected through RT-PCR. A toxicity bioassay against the first instar Aedes albopictus larvae revealed that the pathogenic activity of recombinant AeDNV was significantly higher and faster than the wild-type (wt) viruses, and mortality increased in a dose-dependent manner. The recombinant viruses were genetically stable and displayed growth phenotype and virus proliferation ability, similar to wild-type AeDNV. Our novel results offer further insights by combining two mosquitocidal pathogens to improve viral toxicity for mosquito control.
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Affiliation(s)
- Khadija Batool
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Intikhab Alam
- College of Life Sciences, South China Agricultural University, Guangzhou 510515, China;
| | - Peiwen Liu
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Zeng Shu
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Siyu Zhao
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Wenqiang Yang
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Xiao Jie
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Jinbao Gu
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Xiao-Guang Chen
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
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11
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Sharma M, Kumar V. Mosquito-larvicidal Binary (BinA/B) proteins for mosquito control programs —advancements, challenges, and possibilities. CURRENT RESEARCH IN INSECT SCIENCE 2022; 2:100028. [PMID: 36003274 PMCID: PMC9387486 DOI: 10.1016/j.cris.2021.100028] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 12/11/2021] [Accepted: 12/14/2021] [Indexed: 11/18/2022]
Abstract
Binary (BinAB) toxin is primarily responsible for the larvicidal action of the WHO recognized mosquito-larvicidal bacterium Lysinibacillus sphaericus. BinAB is a single receptor-specific toxin, active against larvae of Culex and Anopheles, but not Aedes aegypti. The target receptor in Culex is Cqm1 protein, a GPI-anchored amylomaltase located apically in the lipid-rafts of the larval-midgut epithelium. Interaction of the toxin components with the receptor is critical for the larvicidal activity of the toxin. Evidences support the pore formation model for BinAB toxin internalization and the role of toxin-glycan interactions in the endoplasmic reticulum in mediating larval death. Targeted R&D efforts are required to maintain the sustainability and improve efficacy of the eco-friendly BinAB proteins for efficient mosquito control interventions.
The increasing global burden of mosquito-borne diseases require targeted, environmentally friendly, and sustainable approaches for effective vector control without endangering the non-target beneficial insect population. Biological interventions such as biopesticides, Wolbachia-mediated biological controls, or sterile insect techniques are used worldwide. Here we review Binary or BinAB toxin—the mosquito-larvicidal component of WHO-recognized Lysinibacillus sphaericus bacterium employed in mosquito control programs. Binary (BinAB) toxin is primarily responsible for the larvicidal effect of the bacterium. BinAB is a single-receptor-specific toxin and is effective against larvae of Culex and Anopheles, but not against Aedes aegypti. The receptor in Culex, the Cqm1 protein, has been extensively studied. It is a GPI-anchored amylomaltase and is located apically in the lipid rafts of the larval-midgut epithelium. The interaction of the toxin components with the receptor is crucial for the mosquito larvicidal activity of the BinAB toxin. Here we extend support for the pore formation model of BinAB toxin internalization and the role of toxin-glycan interactions in the endoplasmic reticulum in mediating larval death. BinAB is phylogenetically safe for humans, as Cqm1-like protein is not expected in the human proteome. This review aims to initiate targeted R&D efforts, such as applying fusion technologies (chimera of BinA, chemical modification of BinA), for efficient mosquito control interventions. In addition, the review also examines other areas such as bioremediation and cancer therapeutics, in which L. sphaericus is proving useful and showing potential for further development.
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Affiliation(s)
- Mahima Sharma
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085, India
| | - Vinay Kumar
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085, India
- Correspondence Author: Professor (Retired) Vinay Kumar, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085, India
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12
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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: 45] [Impact Index Per Article: 15.0] [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.
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Menezes HSG, Nascimento NA, Paiva-Cavalcanti M, da Costa-Latgé SG, Genta FA, Oliveira CM, Romão TP, Silva-Filha MHN. Molecular and biological features of Culex quinquefasciatus homozygous larvae for two cqm1 alleles that confer resistance to Lysinibacillus sphaericus larvicides. PEST MANAGEMENT SCIENCE 2021; 77:3135-3144. [PMID: 33644981 DOI: 10.1002/ps.6349] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/26/2021] [Accepted: 02/28/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Culex quinquefasciatus resistance to the binary toxin from Lysinibacillus sphaericus larvicides can occur because of mutations in the cqm1 gene that prevents the expression of the toxin receptor, Cqm1 α-glucosidase. In a resistant laboratory-selected colony maintained for more than 250 generations, cqm1REC and cqm1REC-2 resistance alleles were identified. The major allele initially found, cqm1REC , became minor and was replaced by cqm1REC-2 . This study aimed to investigate the features associated with homozygous larvae for each allele to understand the reasons for the allele replacement and to generate knowledge on resistance to microbial larvicides. RESULTS Homozygous larvae for each allele were compared. Both larvae displayed the same level of resistance to the binary toxin (3500-fold); therefore, a change in phenotype was not the reason for the replacement observed. The lack of Cqm1 expression did not reduce the total specific α-glucosidase activity for homozygous cqm1REC and cqm1REC-2 larvae, which were statistically similar to the susceptible strain, using artificial or natural substrates. The expression of eight Cqm1 paralog α-glucosidases was demonstrated in resistant and susceptible larvae. Bioassays in which cqm1REC or cqm1REC-2 homozygous larvae were reared under stressful conditions showed that most adults produced were cqm1REC-2 homozygous (69%). Comparatively, in the offspring of a heterozygous sub-colony reared under optimal conditions for 20 generations, the cqm1REC allele assumed a higher frequency (0.72). CONCLUSION Homozygous larvae for each allele exhibited a similar resistant phenotype. However, they presented specific advantages that might favor their selection and can be used in designing resistance management practices. © 2021 Society of Chemical Industry.
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Affiliation(s)
| | | | | | - Samara G da Costa-Latgé
- Laboratory of Insect Biochemistry and Physiology, Instituto Oswaldo Cruz-FIOCRUZ, Rio de Janeiro, Brazil
| | - Fernando A Genta
- Laboratory of Insect Biochemistry and Physiology, Instituto Oswaldo Cruz-FIOCRUZ, Rio de Janeiro, Brazil
| | | | - Tatiany P Romão
- Department of Entomology, Instituto Aggeu Magalhães-FIOCRUZ, Recife, Brazil
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López-Molina S, do Nascimento NA, Silva-Filha MHNL, Guerrero A, Sánchez J, Pacheco S, Gill SS, Soberón M, Bravo A. In vivo nanoscale analysis of the dynamic synergistic interaction of Bacillus thuringiensis Cry11Aa and Cyt1Aa toxins in Aedes aegypti. PLoS Pathog 2021; 17:e1009199. [PMID: 33465145 PMCID: PMC7846010 DOI: 10.1371/journal.ppat.1009199] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 01/29/2021] [Accepted: 11/30/2020] [Indexed: 12/22/2022] Open
Abstract
The insecticidal Cry11Aa and Cyt1Aa proteins are produced by Bacillus thuringiensis as crystal inclusions. They work synergistically inducing high toxicity against mosquito larvae. It was proposed that these crystal inclusions are rapidly solubilized and activated in the gut lumen, followed by pore formation in midgut cells killing the larvae. In addition, Cyt1Aa functions as a Cry11Aa binding receptor, inducing Cry11Aa oligomerization and membrane insertion. Here, we used fluorescent labeled crystals, protoxins or activated toxins for in vivo localization at nano-scale resolution. We show that after larvae were fed solubilized proteins, these proteins were not accumulated inside the gut and larvae were not killed. In contrast, if larvae were fed soluble non-toxic mutant proteins, these proteins were found inside the gut bound to gut-microvilli. Only feeding with crystal inclusions resulted in high larval mortality, suggesting that they have a role for an optimal intoxication process. At the macroscopic level, Cry11Aa completely degraded the gastric caeca structure and, in the presence of Cyt1Aa, this effect was observed at lower toxin-concentrations and at shorter periods. The labeled Cry11Aa crystal protein, after midgut processing, binds to the gastric caeca and posterior midgut regions, and also to anterior and medium regions where it is internalized in ordered "net like" structures, leading finally to cell break down. During synergism both Cry11Aa and Cyt1Aa toxins showed a dynamic layered array at the surface of apical microvilli, where Cry11Aa is localized in the lower layer closer to the cell cytoplasm, and Cyt1Aa is layered over Cry11Aa. This array depends on the pore formation activity of Cry11Aa, since the non-toxic mutant Cry11Aa-E97A, which is unable to oligomerize, inverted this array. Internalization of Cry11Aa was also observed during synergism. These data indicate that the mechanism of action of Cry11Aa is more complex than previously anticipated, and may involve additional steps besides pore-formation activity.
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Affiliation(s)
- Samira López-Molina
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | | | | | - Adán Guerrero
- Laboratorio Nacional de Microscopía Avanzada, Instituto de Biotecnología, UNAM, Cuernavaca, Morelos, Mexico
| | - Jorge Sánchez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Sabino Pacheco
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Sarjeet S. Gill
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, California, United States of America
| | - Mario Soberón
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Alejandra Bravo
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
- * E-mail:
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