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Wolstenholme AJ, Andersen EC, Choudhary S, Ebner F, Hartmann S, Holden-Dye L, Kashyap SS, Krücken J, Martin RJ, Midha A, Nejsum P, Neveu C, Robertson AP, von Samson-Himmelstjerna G, Walker R, Wang J, Whitehead BJ, Williams PDE. Getting around the roundworms: Identifying knowledge gaps and research priorities for the ascarids. ADVANCES IN PARASITOLOGY 2024; 123:51-123. [PMID: 38448148 PMCID: PMC11143470 DOI: 10.1016/bs.apar.2023.12.002] [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] [Indexed: 03/08/2024]
Abstract
The ascarids are a large group of parasitic nematodes that infect a wide range of animal species. In humans, they cause neglected diseases of poverty; many animal parasites also cause zoonotic infections in people. Control measures include hygiene and anthelmintic treatments, but they are not always appropriate or effective and this creates a continuing need to search for better ways to reduce the human, welfare and economic costs of these infections. To this end, Le Studium Institute of Advanced Studies organized a two-day conference to identify major gaps in our understanding of ascarid parasites with a view to setting research priorities that would allow for improved control. The participants identified several key areas for future focus, comprising of advances in genomic analysis and the use of model organisms, especially Caenorhabditis elegans, a more thorough appreciation of the complexity of host-parasite (and parasite-parasite) communications, a search for novel anthelmintic drugs and the development of effective vaccines. The participants agreed to try and maintain informal links in the future that could form the basis for collaborative projects, and to co-operate to organize future meetings and workshops to promote ascarid research.
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Affiliation(s)
- Adrian J Wolstenholme
- Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), Université de Tours, ISP, Nouzilly, France.
| | - Erik C Andersen
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
| | - Shivani Choudhary
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
| | - Friederike Ebner
- Department of Molecular Life Sciences, School of Life Sciences, Technische Universität München, Freising, Germany
| | - Susanne Hartmann
- Institute for Immunology, Freie Universität Berlin, Berlin, Germany
| | - Lindy Holden-Dye
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Sudhanva S Kashyap
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
| | - Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Richard J Martin
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
| | - Ankur Midha
- Institute for Immunology, Freie Universität Berlin, Berlin, Germany
| | - Peter Nejsum
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Cedric Neveu
- Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), Université de Tours, ISP, Nouzilly, France
| | - Alan P Robertson
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
| | | | - Robert Walker
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Jianbin Wang
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, United States
| | | | - Paul D E Williams
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
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Reid G. A value chain to improve human, animal and insect health in developing countries. MICROBIOME RESEARCH REPORTS 2023; 3:10. [PMID: 38455087 PMCID: PMC10917616 DOI: 10.20517/mrr.2023.46] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 11/30/2023] [Accepted: 12/04/2023] [Indexed: 03/09/2024]
Affiliation(s)
- Gregor Reid
- Canadian R&D Centre for Human Microbiome and Probiotics, Lawson Health Research Institute, London N6A 4V2, Ontario, Canada
- Departments of Microbiology and Immunology, and Surgery, Western University, London N6A 4V2, Ontario, Canada
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3
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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.
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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
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Sakdee S, Aroonkesorn A, Imtong C, Li HC, Angsuthanasombat C. Optimized high-yield preparation of alkaline-solubilizable crystalline inclusion of the Bacillus thuringiensis Cry4Aa δ-endotoxin expressed in Escherichia coli. Protein Expr Purif 2023; 210:106320. [PMID: 37301245 DOI: 10.1016/j.pep.2023.106320] [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: 02/01/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/12/2023]
Abstract
The native Cry4Aa δ-endotoxin produced exclusively in Bacillus thuringiensis during sporulation as a ∼130-kDa inactive protoxin is confined within the parasporal crystalline inclusion that dissolves at alkaline pH in the midgut lumen of mosquito larvae. Here, the recombinant Cry4Aa toxin over-expressed in Escherichia coli at 30 °C as an alkaline-sobubilizable inclusion was found inevitably lost during isolation from the cell lysate (pH ∼6.5) of which host cells were pre-suspended in distilled water (pH ∼5.5). When 100 mM KH2PO4 (pH 5.0) was used as host cell-suspending buffer, the cell lysate's pH became more acidic (pH 5.5), allowing the expressed protoxin to be entirely retained in the form of crystalline inclusion rather than a soluble form, and thus high-yield recovery of the partially purified inclusion was obtained. Upon dialysis of the alkaline-solubilized protoxin against the KH2PO4 buffer, the protoxin precipitate was efficiently recovered and still exhibited high toxicity to Aedes aegypti mosquito larvae. Additionally, the precipitated protoxin was completely resolubilized in 50 mM Na2CO3 buffer (pH 9.0) and proteolytically processed by trypsin to produce the 65-kDa activated toxin comprising ∼47- and ∼20-kDa fragments. In silico structural analysis suggested that His154, His388, His536 and His572 were involved in a dissolution of the Cry4Aa inclusion at pH 6.5, conceivably through interchain salt bridge breakage. Altogether, such an optimized protocol described herein was effective for the preparation of alkaline-solubilizable inclusions of the recombinant Cry4Aa toxin in large amounts (>25 mg per liter culture) that would pave the way for further structure-function relationship studies of different Cry toxins.
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Affiliation(s)
- Somsri Sakdee
- Bacterial Toxin Research Innovation Laboratory, Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakornpathom, 73170, Thailand
| | - Aratee Aroonkesorn
- Division of Health and Applied Sciences, Biochemistry Graduate Program, Faculty of Science, Prince of Songkla University, Hatyai, Songkhla, 90110, Thailand
| | - Chompounoot Imtong
- Biophysics Institute for Research and Development (BIRD), Chiang Mai, 50110, Thailand
| | - Hui-Chun Li
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, 97004, Taiwan
| | - Chanan Angsuthanasombat
- Bacterial Toxin Research Innovation Laboratory, Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakornpathom, 73170, Thailand; Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, 97004, Taiwan; Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
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Kinkar OU, Prashar A, Yadav B, Kumar A, Hadapad AB, Hire RS, Makde RD. Purification, characterization and proteolytic processing of mosquito larvicidal protein Cry11Aa from Bacillus thuringensis subsp. isralensis ISPC-12. Int J Biol Macromol 2023:124979. [PMID: 37245748 DOI: 10.1016/j.ijbiomac.2023.124979] [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: 02/23/2023] [Revised: 05/17/2023] [Accepted: 05/18/2023] [Indexed: 05/30/2023]
Abstract
Cry11Aa is the most potent mosquito larvicidal protein of Bacillus thuringiensis subsp. israelensis (Bti). Development of resistance against insecticidal proteins including Cry11Aa is known but no field resistance was observed with Bti. The phenomenon of increasing resistance in insect pests necessitates the development of new strategies and techniques to enhance efficacy of insecticidal proteins. Recombinant technology offers better control over the molecule and allows modification of protein to achieve maximal effect against target pests. In this study, we standardised protocol for recombinant purification of Cry11Aa. Recombinant Cry11Aa found active against larvae of Aedes and Culex mosquito species and LC50 were estimated. Detailed biophysical characterization provides crucial insights into stability and in-vitro behaviour of the recombinant Cry11Aa. Moreover, trypsin hydrolysis doesn't improve overall toxicity of recombinant Cry11Aa. Proteolytic processing suggests domain I and II are more prone to proteolysis in comparison to domain III. Significance of structural features for proteolysis of Cry11Aa was observed after performing molecular dynamics simulations. Findings reported here are contributing significantly in method for purification, understanding in-vitro behaviour and proteolytic processing of Cry11Aa which could facilitate in efficient utilisation of Bti for insect pests and vectors control.
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Affiliation(s)
- Omkar U Kinkar
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, Maharashtra, India; Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - Arpit Prashar
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Beena Yadav
- Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - Ashwani Kumar
- Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Ashok B Hadapad
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Ramesh S Hire
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, Maharashtra, India; Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Ravindra D Makde
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, Maharashtra, India; Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
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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.
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Meier CJ, Rouhier MF, Hillyer JF. Chemical Control of Mosquitoes and the Pesticide Treadmill: A Case for Photosensitive Insecticides as Larvicides. INSECTS 2022; 13:1093. [PMID: 36555003 PMCID: PMC9783766 DOI: 10.3390/insects13121093] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
Insecticides reduce the spread of mosquito-borne disease. Over the past century, mosquito control has mostly relied on neurotoxic chemicals-such as pyrethroids, neonicotinoids, chlorinated hydrocarbons, carbamates and organophosphates-that target adults. However, their persistent use has selected for insecticide resistance. This has led to the application of progressively higher amounts of insecticides-known as the pesticide treadmill-and negative consequences for ecosystems. Comparatively less attention has been paid to larvae, even though larval death eliminates a mosquito's potential to transmit disease and reproduce. Larvae have been targeted by source reduction, biological control, growth regulators and neurotoxins, but hurdles remain. Here, we review methods of mosquito control and argue that photoactive molecules that target larvae-called photosensitive insecticides or PSIs-are an environmentally friendly addition to our mosquitocidal arsenal. PSIs are ingested by larvae and produce reactive oxygen species (ROS) when activated by light. ROS then damage macromolecules resulting in larval death. PSIs are degraded by light, eliminating environmental accumulation. Moreover, PSIs only harm small translucent organisms, and their broad mechanism of action that relies on oxidative damage means that resistance is less likely to evolve. Therefore, PSIs are a promising alternative for controlling mosquitoes in an environmentally sustainable manner.
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Affiliation(s)
- Cole J. Meier
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
| | | | - Julián F. Hillyer
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
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8
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Dechkla M, Charoenjotivadhanakul S, Imtong C, Visitsattapongse S, Li HC, Angsuthanasombat C. Cry4Aa and Cry4Ba Mosquito-Active Toxins Utilize Different Domains in Binding to a Particular Culex ALP Isoform: A Functional Toxin Receptor Implicating Differential Actions on Target Larvae. Toxins (Basel) 2022; 14:toxins14100652. [PMID: 36287921 PMCID: PMC9607545 DOI: 10.3390/toxins14100652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/10/2022] [Accepted: 09/16/2022] [Indexed: 11/16/2022] Open
Abstract
The three-domain Cry4Aa toxin produced from Bacillus thuringiensis subsp. israelensis was previously shown to be much more toxic to Culex mosquito larvae than its closely related toxin—Cry4Ba. The interaction of these two individual toxins with target receptors on susceptible larval midgut cells is likely to be the critical determinant in their differential toxicity. Here, two full-length membrane-bound alkaline phosphatase (mALP) isoforms from Culex quinquefasciatus larvae, Cq-mALP1263and Cq-mALP1264, predicted to be GPI-linked was cloned and functionally expressed in Spodoptera frugiperda (Sf9) cells as 57- and 61-kDa membrane-bound proteins, respectively. Bioinformatics analysis disclosed that both Cq-mALP isoforms share significant sequence similarity to Aedes aegypti-mALP—a Cry4Ba toxin receptor. In cytotoxicity assays, Sf9 cells expressing Cq-mALP1264, but not Cq-mALP1263, showed remarkably greater susceptibility to Cry4Aa than Cry4Ba, while immunolocalization studies revealed that both toxins were capable of binding to each Cq-mALP expressed on the cell membrane surface. Molecular docking of the Cq-mALP1264-modeled structure with individual Cry4 toxins revealed that Cry4Aa could bind to Cq-mALP1264 primarily through particular residues on three surface-exposed loops in the receptor-binding domain—DII, including Thr512, Tyr513 and Lys514 in the β10-β11loop. Dissimilarly, Cry4Ba appeared to utilize only certain residues in its C-terminal domain—DIII to interact with such a Culex counterpart receptor. Ala-substitutions of selected β10-β11loop residues (T512A, Y513A and K514A) revealed that only the K514A mutant displayed a drastic decrease in biotoxicity against C. quinquefasciatus larvae. Further substitution of Lys514 with Asp (K514D) revealed a further decrease in larval toxicity. Furthermore, in silico calculation of the binding affinity change (ΔΔGbind) in Cry4Aa-Cq-mALP1264 interactions upon these single-substitutions revealed that the K514D mutation displayed the largest ΔΔGbind value as compared to three other mutations, signifying an adverse impact of a negative charge at this critical receptor-binding position. Altogether, our present study has disclosed that these two related-Cry4 mosquito-active toxins conceivably exploited different domains in functional binding to the same Culex membrane-bound ALP isoform—Cq-mALP1264 for mediating differential toxicity against Culex target larvae.
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Affiliation(s)
- Manussawee Dechkla
- Department of Environmental Biology, Faculty of Science and Technology, Suan Sunandha Rajabhat University, Bangkok 10300, Thailand
- Correspondence: (M.D.); (C.A.)
| | - Sathapat Charoenjotivadhanakul
- Bacterial Toxin Research Innovation Cluster (BRIC), Institute of Molecular Biosciences, Salaya Campus, Mahidol University, Nakorn Pathom 73170, Thailand
| | - Chompounoot Imtong
- Laboratory of Structural Biochemistry and Cell Chemical Biology, Biophysics Institute for Research and Development (BIRD), Fang, Chiang Mai 50110, Thailand
| | - Sarinporn Visitsattapongse
- Department of Biomedical Engineering, School of Engineering, King Mongkut’s Institute of Technology Ladkrabang, Ladkrabang, Bangkok 10520, Thailand
| | - Hui-Chun Li
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
| | - Chanan Angsuthanasombat
- Bacterial Toxin Research Innovation Cluster (BRIC), Institute of Molecular Biosciences, Salaya Campus, Mahidol University, Nakorn Pathom 73170, Thailand
- Laboratory of Structural Biochemistry and Cell Chemical Biology, Biophysics Institute for Research and Development (BIRD), Fang, Chiang Mai 50110, Thailand
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
- Correspondence: (M.D.); (C.A.)
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Complete structure elucidation of a functional form of the Bacillus thuringiensis Cry4Ba δ-endotoxin: Insights into toxin-induced transmembrane pore architecture. Biochem Biophys Res Commun 2022; 620:158-164. [DOI: 10.1016/j.bbrc.2022.06.065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 06/21/2022] [Indexed: 11/24/2022]
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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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Mitochondrial composition of and diffusion limiting factors of three social wasp genera Polistes, Ropalidia, and parapolybia (Hymenoptera: Vespidae). BMC Ecol Evol 2022; 22:63. [PMID: 35550012 PMCID: PMC9097357 DOI: 10.1186/s12862-022-02017-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 05/02/2022] [Indexed: 11/10/2022] Open
Abstract
Background Social wasps Polistes, Ropalidia, and Parapolybia, belonging to the subfamily Polistinae, have obviously different distribution patterns, yet the factors leading to this difference remain unknown. Results The 17 newly sequenced mitogenomes of Polistes, Ropalidia, and Parapolybia contain 37 genes, and there are obvious differences among the compositions of the three genera. The monophyly of the genus Polistes and a monophyletic Ropalidiini: (Ropalidia + Parapolybia) are concordant with previous morphological analysis of the subfamily Polistinae. Our inferred divergence time demonstrates Polistes (at around 69 Ma) was diverged earlier than Ropalidia and Parapolybia (at around 61 Ma). The rearrangement of both trnY and trnL1 are shared by all the Polistinae. In addition, the unique rearrangement of TDRL derived at 69 Ma is detected in Polistes, and Ropalidia contains a Reversal which may derive at 61 Ma. Hereafter, the possibility is elaborated that Polistes originated in Aisa and then dispersed from Africa to South America, and Polistes and Ropalidia spread from Southeast Asia to Australia. At last, continental drift and Quaternary Ice Ages are inferred to be two main limiting factors in the current distributions of the three genera. Conclusions Obvious differences occur in the mitochondrial composition of Polistes, Ropalidia, and Parapolybia. According to the reconstructed time-calibrated framework, it is inquired that the continental drifts and the climate are mainly diffusion limiting factors of the three genera. Supplementary information The online version contains supplementary material available at 10.1186/s12862-022-02017-6.
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12
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Rezende-Teixeira P, Dusi RG, Jimenez PC, Espindola LS, Costa-Lotufo LV. What can we learn from commercial insecticides? Efficacy, toxicity, environmental impacts, and future developments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 300:118983. [PMID: 35151812 DOI: 10.1016/j.envpol.2022.118983] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/26/2022] [Accepted: 02/08/2022] [Indexed: 05/27/2023]
Abstract
Worldwide pesticide usage was estimated in up to 3.5 million tons in 2020. The number of approved products varies among different countries, however, in Brazil, there are nearly 5000 of such products available. Among them, insecticides correspond to a group of mounting importance for controlling crop pests and disease-associated vectors in public health. Unfortunately, resistance to commercially approved insecticides is commonly observed, limiting the use of these products. Thus, the search for more effective and environmentally friendly products is both a challenge and a necessity since several insecticides are no longer allowed in many countries. In this review, we discuss the historical strategies used in the development of modern insecticides, including chemical structure alterations, mechanism of action and their impact on insecticidal activity. The environmental impact of each pesticide class is also discussed, with persistence data and activity on non-target organisms, along with the human toxicological effect. By tracing the historical route of discovery and development of blockbuster pesticides like DDT, pyrethroids and organophosphates, we also aim to categorize and relate the successful chemical alterations and novel pesticide development strategies that resulted in safer alternatives. A brief discussion on the Brazilian registration procedure and a perspective of insecticides currently approved in the country was also included.
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Affiliation(s)
- Paula Rezende-Teixeira
- Laboratório de Farmacologia Marinha, Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, 05508-900, São Paulo, SP, Brazil
| | - Renata G Dusi
- Laboratório de Farmacognosia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Brasília, 70910-900, Brazil
| | - Paula C Jimenez
- Laboratório de Bioprospecção de Organismos Marinhos, Instituto do Mar, Universidade Federal de São Paulo, Santos, SP, Brazil
| | - Laila S Espindola
- Laboratório de Farmacognosia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Brasília, 70910-900, Brazil
| | - Letícia V Costa-Lotufo
- Laboratório de Farmacologia Marinha, Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, 05508-900, São Paulo, SP, Brazil.
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Kuwar SS, Mishra R, Banerjee R, Milligan J, Rydel T, Du Z, Xie Z, Ivashuta S, Kouadio JL, Meyer JM, Bonning BC. Engineering of Cry3Bb1 provides mechanistic insights toward countering western corn rootworm resistance. CURRENT RESEARCH IN INSECT SCIENCE 2022; 2:100033. [PMID: 36003270 PMCID: PMC9387510 DOI: 10.1016/j.cris.2022.100033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 11/28/2022]
Abstract
Cry3Bb1 engineering for receptor retargeting to counter WCR resistance described Phage display screens against BBMV or recombinant insecticidal-protein receptors 77 gut binding peptides selected and engineered into 284 new variants of Cry3Bb1 112 variants were active against susceptible but not resistant WCR Engineering of Cry3Bb1 Domain II loops 1 and 2 disrupted insecticidal activity Sites for Cry3Bb1 engineering and implications for Cry3Bb1 resistance discussed
The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is an economically important pest of corn (maize) in North America and Europe. Current management practices for WCR involve transgenic expression of insecticidal proteins to minimize larval feeding damage to corn roots. The evolution of resistant WCR populations to transgenic corn expressing insecticidal proteins (e.g. Cry3Bb1, Gpp34Ab1/Tpp35Ab1) necessitates efforts to discover and deploy new modes of action for WCR control. Here, we tested the hypothesis that the addition of short peptides selected for binding to the WCR gut would restore insecticidal activity of Cry3Bb1 to resistant insects. Phage display technology coupled with deep sequencing was used to identify peptides selected for binding to WCR brush border membrane vesicles and to recombinant putative receptors aminopeptidase and cadherin. The binding and specificity of selected peptides was confirmed by ELISA and pull-down assays, and candidate gut surface binding partners were identified. Although production of 284 novel Cry3Bb1 variants with these peptides did not restore activity against resistant WCR in artificial diet bioassays, 112 variants were active against susceptible insects. These results provided insights for the mechanism of Cry3Bb1 activity and toward engineering a new mode-of-action via receptor re-targeting in the context of protein structure and function.
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Affiliation(s)
- Suyog S. Kuwar
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
| | - Ruchir Mishra
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
| | - Rahul Banerjee
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
| | - Jason Milligan
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Timothy Rydel
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Zijin Du
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Zhidong Xie
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Sergey Ivashuta
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Jean-Louis Kouadio
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Jason M. Meyer
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Bryony C. Bonning
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
- Corresponding author: Department of Entomology and Nematology, University of Florida, PO Box 110620, Gainesville, FL 32611.
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14
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Huang L, Xu L, Han G, Crickmore N, Song F, Xu J. Characterization of CwlC, an autolysin, and its role in mother cell lysis of Bacillus thuringiensis subsp. israelensis. Lett Appl Microbiol 2021; 74:92-102. [PMID: 34695235 DOI: 10.1111/lam.13590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/13/2021] [Accepted: 10/15/2021] [Indexed: 11/27/2022]
Abstract
Bacillus thuringiensis subsp. israelensis (Bti) has been proven to efficiently control mosquitoes, of which many species are important vectors of human disease. The larvicidal action is attributed to the parasporal crystals formed in the sporulating cells and released upon cell autolysis. In this study, a sporulation-specific cwlC gene that encodes an N-acetylmuramoyl-L -alanine amidase was characterized in Bti strain Bt-59. CwlC was the only cell wall hydrolase in Bti found to contain both MurNAc-LAA and Amidase02_C domains. A recombinant CwlC-His protein was able to digest the Bacillus cell wall. Deletion of the cwlC gene delayed Bti mother cell lysis without impacting vegetative growth or insecticidal efficacy. Transcriptional analyses indicated that cwlC was expressed at the late sporulation stage and was controlled by SigK. Two other cell wall hydrolase genes, cwlB and cwlE, with high expression levels at T14 in Bt-59, were also identified. Like cwlC, cwlB expression was controlled by SigK; in contrast, cwlE was found not to be under the control of this sigma factor and unlike the other two, its gene was found to be plasmid encoded.
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Affiliation(s)
- L Huang
- Department of Applied Microbiology, Jiangsu Lixiahe District Institute of Agricultural Sciences/National Agricultural Experimental Station for Agricultural Microbiology, Yangzhou, China
| | - L Xu
- Department of Applied Microbiology, Jiangsu Lixiahe District Institute of Agricultural Sciences/National Agricultural Experimental Station for Agricultural Microbiology, Yangzhou, China.,State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - G Han
- Department of Applied Microbiology, Jiangsu Lixiahe District Institute of Agricultural Sciences/National Agricultural Experimental Station for Agricultural Microbiology, Yangzhou, China
| | - N Crickmore
- Department of Biochemistry, School of Biological Sciences, University of Sussex, Brighton, UK
| | - F Song
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - J Xu
- Department of Applied Microbiology, Jiangsu Lixiahe District Institute of Agricultural Sciences/National Agricultural Experimental Station for Agricultural Microbiology, Yangzhou, China
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Milugo TK, Tchouassi DP, Kavishe RA, Dinglasan RR, Torto B. Naturally Occurring Compounds With Larvicidal Activity Against Malaria Mosquitoes. FRONTIERS IN TROPICAL DISEASES 2021. [DOI: 10.3389/fitd.2021.718804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Female Anopheles mosquitoes transmit Plasmodium parasites that cause human malaria. Currently, vector control is the most widely deployed approach to reduce mosquito population and hence disease transmission. This relies on use of insecticide-based interventions including Long-lasting Insecticide-treated Nets (LLINs) and Indoor Residual Spraying (IRS) where scale-up has contributed to a dramatic decline in malaria deaths and morbidity over the past decade. Challenges to their effective use include the emergence and spread of insecticide resistance by malaria vector populations coupled with the inability to curb outdoor transmission. Under these situations, use of larvicides through larval source management (LSM) can complement these existing measures. The need to minimize environmental impact and effect on non-target organisms has spurred interest in the development of eco-friendly larvicides of natural origin. Here, we review literature published in the last five years to highlight compounds of natural origin found to exhibit larvicidal activity against malaria mosquitoes. Specifically, the larvicidal activity of different classes of compounds is discussed including their effect on non-target organisms. Additionally, we provide suggestions for future research into mosquito larvicides including the use of chemical synthesis to improve the bioactivity of known natural compounds.
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Thammasittirong A, Thammasittirong SNR, Imtong C, Charoenjotivadhanakul S, Sakdee S, Li HC, Okonogi S, Angsuthanasombat C. Bacillus thuringiensis Cry4Ba Insecticidal ToxinExploits Leu 615 in Its C-Terminal Domain to Interact with a Target Receptor- Aedes aegypti Membrane-Bound Alkaline Phosphatase. Toxins (Basel) 2021; 13:toxins13080553. [PMID: 34437424 PMCID: PMC8402544 DOI: 10.3390/toxins13080553] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/27/2021] [Accepted: 08/03/2021] [Indexed: 11/16/2022] Open
Abstract
In addition to the receptor-binding domain (DII), the C-terminal domain (DIII) of three-domain Cry insecticidal δ-endotoxins from Bacillus thuringiensis has been implicated in target insect specificity, yet its precise mechanistic role remains unclear. Here, the 21 kDa high-purity isolated DIII fragment derived from the Cry4Ba mosquito-specific toxin was achieved via optimized preparative FPLC, allowing direct rendering analyses for binding characteristics toward its target receptor—Aedes aegypti membrane-bound alkaline phosphatase (Aa-mALP). Binding analysis via dotblotting revealed that the Cry4Ba-DIII truncate was capable of specific binding to nitrocellulose-bound Aa-mALP, with a binding signal comparable to its 65 kDa Cry4Ba-R203Q full-length toxin. Further determination of binding affinity via sandwich ELISA revealed that Cry4Ba-DIII exhibited a rather weak binding to Aa-mALP with a dissociation constant (Kd) of ≈1.1 × 10−7 M as compared with the full-length toxin. Intermolecular docking between the Cry4Ba-R203Q active toxin and Aa-mALP suggested that four Cry4Ba-DIII residues, i.e., Glu522, Asn552, Asn576, and Leu615, are potentially involved in such toxin–receptor interactions. Ala substitutions of each residue (E522A, N552A, N576A and L615A) revealed that only the L615A mutant displayed a drastic decrease in biotoxicity against A. aegypti larvae. Additional binding analysis revealed that the L615A-impaired toxin also exhibited a reduction in binding capability to the surface-immobilized Aa-mALP receptor, while two bio-inactive DII-mutant toxins, Y332A and F364A, which almost entirely lost their biotoxicity, apparently retained a higher degree of binding activity. Altogether, our data disclose a functional importance of the C-terminal domain of Cry4Ba for serving as a potential receptor-binding moiety in which DIII-Leu615 could conceivably be exploited for the binding to Aa-mALP, highlighting its contribution to toxin interactions with such a target receptor in mediating larval toxicity.
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Affiliation(s)
- Anon Thammasittirong
- Microbial Biotechnology Unit, Department of Microbiology, Faculty of Liberal Arts and Science, Kasetsart University, Nakhon Pathom 73140, Thailand;
- Correspondence: (A.T.); (C.A.)
| | - Sutticha Na-Ranong Thammasittirong
- Microbial Biotechnology Unit, Department of Microbiology, Faculty of Liberal Arts and Science, Kasetsart University, Nakhon Pathom 73140, Thailand;
| | - Chompounoot Imtong
- Faculty of Science and Technology, Prince of Songkla University, Pattani 94000, Thailand;
| | - Sathapat Charoenjotivadhanakul
- Bacterial Toxin Research Innovation Cluster (BRIC), Institute of Molecular Biosciences, Salaya Campus, Mahidol University, Nakorn Pathom 73170, Thailand; (S.C.); (S.S.)
| | - Somsri Sakdee
- Bacterial Toxin Research Innovation Cluster (BRIC), Institute of Molecular Biosciences, Salaya Campus, Mahidol University, Nakorn Pathom 73170, Thailand; (S.C.); (S.S.)
| | - Hui-Chun Li
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan;
| | - Siriporn Okonogi
- Research Center of Pharmaceutical Nanotechnology, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Chanan Angsuthanasombat
- Bacterial Toxin Research Innovation Cluster (BRIC), Institute of Molecular Biosciences, Salaya Campus, Mahidol University, Nakorn Pathom 73170, Thailand; (S.C.); (S.S.)
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan;
- Laboratory of Synthetic Biophysics and Chemical Biology, Biophysics Institute for Research and Development (BIRD), Chiang Mai 50130, Thailand
- Correspondence: (A.T.); (C.A.)
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17
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Caragata EP, Dong S, Dong Y, Simões ML, Tikhe CV, Dimopoulos G. Prospects and Pitfalls: Next-Generation Tools to Control Mosquito-Transmitted Disease. Annu Rev Microbiol 2021; 74:455-475. [PMID: 32905752 DOI: 10.1146/annurev-micro-011320-025557] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mosquito-transmitted diseases, including malaria and dengue, are a major threat to human health around the globe, affecting millions each year. A diverse array of next-generation tools has been designed to eliminate mosquito populations or to replace them with mosquitoes that are less capable of transmitting key pathogens. Many of these new approaches have been built on recent advances in CRISPR/Cas9-based genome editing. These initiatives have driven the development of pathogen-resistant lines, new genetics-based sexing methods, and new methods of driving desirable genetic traits into mosquito populations. Many other emerging tools involve microorganisms, including two strategies involving Wolbachia that are achieving great success in the field. At the same time, other mosquito-associated bacteria, fungi, and even viruses represent untapped sources of new mosquitocidal or antipathogen compounds. Although there are still hurdles to be overcome, the prospect that such approaches will reduce the impact of these diseases is highly encouraging.
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Affiliation(s)
- E P Caragata
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA; , , , , ,
| | - S Dong
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA; , , , , ,
| | - Y Dong
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA; , , , , ,
| | - M L Simões
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA; , , , , ,
| | - C V Tikhe
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA; , , , , ,
| | - G Dimopoulos
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA; , , , , ,
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18
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de Oliveira JL, Fraceto LF, Bravo A, Polanczyk RA. Encapsulation Strategies for Bacillus thuringiensis: From Now to the Future. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:4564-4577. [PMID: 33848162 DOI: 10.1021/acs.jafc.0c07118] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Bacillus thuringiensis (Bt) has been recognized for its high potential in the control of various agricultural pests. Developments in micro/nanotechnology have opened new perspectives for the production of more efficient formulations that can overcome some obstacles associated with its use in the field, such as formulation instability and loss of activity as a result of the degradation of pesticidal protein by its exposure to ultraviolet radiation, among other problems. This review describes current studies and recent discoveries related to Bt and processes for the encapsulation of Bt derivatives, such as Cry pesticidal proteins. Different techniques are described, such as extrusion, emulsion, spray drying, spray cooling, fluidized bed, lyophilization, coacervation, and electrospraying to obtain micro- and nanoparticulate systems. It is noteworthy that products based on microorganisms present less risk to the environment and non-target organisms. However, systematic risk assessment studies of these new Bt biopesticides are necessary, considering issues, such as interactions with other organisms, the formation of toxic secondary metabolites, or the interspecific transfer of genetic material. Given the great potential of these new formulations, a critical assessment is provided for their future use, considering the technological challenges that must be overcome to achieve their large-scale production for efficient agricultural use.
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Affiliation(s)
- Jhones L de Oliveira
- Department of Agricultural Production Sciences, Faculty of Agronomy and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal, São Paulo 14884-900, Brazil
| | - Leonardo Fernandes Fraceto
- Institute of Science and Technology, São Paulo State University (UNESP), Avenida Três de Março 511, Alto da Boa Vista, Sorocaba, São Paulo 18087-180, Brazil
| | - Alejandra Bravo
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 201, Colonia Chamilpa, Cuernavaca, Morelos 62210, Mexico
| | - Ricardo Antonio Polanczyk
- Department of Agricultural Production Sciences, Faculty of Agronomy and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal, São Paulo 14884-900, Brazil
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19
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Bourchookarn W, Bourchookarn A, Imtong C, Li HC, Angsuthanasombat C. His 180 in the pore-lining α4 of the Bacillus thuringiensis Cry4Aa δ-endotoxin is crucial for structural arrangements of the α4-α5 transmembrane hairpin and hence biotoxicity. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2021; 1869:140634. [PMID: 33636413 DOI: 10.1016/j.bbapap.2021.140634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 02/15/2021] [Accepted: 02/19/2021] [Indexed: 10/22/2022]
Abstract
One proposed toxic mechanism of Bacillus thuringiensis Cry δ-endotoxins involves pore formation in target membranes by the α4-α5 transmembrane hairpin constituting their pore-forming domain. Here, nine selected charged and uncharged polar residues in the pore-lining α4 of the Cry4Aa mosquito-active toxin were substituted with Ala. All mutant toxins, i.e., D169A, R171A, Q173A, H178A, Y179A, H180A, Q182A, N183A and E187A, were over-expressed in Escherichia coli as 130-kDa protoxin inclusions at levels comparable to the wild-type toxin. Bioassays against Aedes aegypti larvae revealed that only H178A and H180A mutants displayed a drastic reduction in biotoxicity, albeit almost complete insolubility observed for H178A, but not for H180A inclusions. Further mutagenic analysis showed that replacements of His180 with charged (Arg, Lys, Asp, Glu), small uncharged polar (Ser, Cys) or small non-polar (Gly, Val) residues severely impaired the biotoxicity, unlike substitutions with relatively large uncharged (Asn, Gln, Leu) or aromatic (Phe, Tyr, Trp) residues. Similar to the trypsin-activated wild-type toxin, both bio-active and -inactive H180 mutants were still capable of releasing entrapped calcein from lipid vesicles and producing cation-selective channels with ~130-pS maximum conductance. Analysis of the Cry4Aa structure revealed the existence of a hydrophobic cavity near the critical His180 side-chain. Analysis of simulated structures revealed that His180-to-smaller residue conversions create a gap disrupting such cavity's hydrophobicity and hence structural arrangements of the α4-α5 hairpin. Altogether, our data disclose a critical involvement in Cry4Aa-biotoxicity of His180 exclusively present in the lumen-facing α4 for providing proper environment for the α4-α5 hairpin prior to membrane-inserted pore formation.
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Affiliation(s)
- Walairat Bourchookarn
- Faculty of Science and Technology, Prince of Songkla University, Pattani 94000, Thailand
| | - Apichai Bourchookarn
- Faculty of Science and Technology, Prince of Songkla University, Pattani 94000, Thailand.
| | - Chompounoot Imtong
- Faculty of Science and Technology, Prince of Songkla University, Pattani 94000, Thailand
| | - Hui-Chun Li
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
| | - Chanan Angsuthanasombat
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan; Laboratory of Synthetic Biophysics and Chemical Biology, Biophysics Institute for Research and Development (BIRD), Chiang Mai 50230, Thailand; Bacterial Toxin Research Innovation Cluster (BRIC), Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakornpathom 73170, Thailand.
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20
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Bonis M, Felten A, Pairaud S, Dijoux A, Maladen V, Mallet L, Radomski N, Duboisset A, Arar C, Sarda X, Vial G, Mistou MY, Firmesse O, Hennekinne JA, Herbin S. Comparative phenotypic, genotypic and genomic analyses of Bacillus thuringiensis associated with foodborne outbreaks in France. PLoS One 2021; 16:e0246885. [PMID: 33607651 PMCID: PMC7895547 DOI: 10.1371/journal.pone.0246885] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/28/2021] [Indexed: 11/18/2022] Open
Abstract
Bacillus thuringiensis (Bt) belongs to the Bacillus cereus (Bc) group, well known as an etiological agent of foodborne outbreaks (FBOs). Bt distinguishes itself from other Bc by its ability to synthesize insecticidal crystals. However, the search for these crystals is not routinely performed in food safety or clinical investigation, and the actual involvement of Bt in the occurrence of FBOs is not known. In the present study, we reveal that Bt was detected in the context of 49 FBOs declared in France between 2007 and 2017. In 19 of these FBOs, Bt was the only microorganism detected, making it the most likely causal agent. Searching for its putative origin of contamination, we noticed that more than 50% of Bt isolates were collected from dishes containing raw vegetables, in particular tomatoes (48%). Moreover, the genomic characterization of isolates showed that most FBO-associated Bt isolates exhibited a quantified genomic proximity to Bt strains, used as biopesticides, especially those from subspecies aizawai and kurstaki. Taken together, these results strengthen the hypothesis of an agricultural origin for the Bt contamination and call for further investigations on Bt pesticides.
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Affiliation(s)
- Mathilde Bonis
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Arnaud Felten
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Sylvie Pairaud
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Angélie Dijoux
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Véronique Maladen
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Ludovic Mallet
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Nicolas Radomski
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Arnaud Duboisset
- Regulated Products Assessment Department, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Chantal Arar
- Regulated Products Assessment Department, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Xavier Sarda
- Regulated Products Assessment Department, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Gaelle Vial
- Regulated Products Assessment Department, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Michel-Yves Mistou
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Olivier Firmesse
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
- * E-mail:
| | - Jacques-Antoine Hennekinne
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
| | - Sabine Herbin
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, Maisons-Alfort, France
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21
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Potential for Bacillus thuringiensis and Other Bacterial Toxins as Biological Control Agents to Combat Dipteran Pests of Medical and Agronomic Importance. Toxins (Basel) 2020; 12:toxins12120773. [PMID: 33291447 PMCID: PMC7762171 DOI: 10.3390/toxins12120773] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 11/24/2020] [Accepted: 12/03/2020] [Indexed: 11/16/2022] Open
Abstract
The control of dipteran pests is highly relevant to humans due to their involvement in the transmission of serious diseases including malaria, dengue fever, Chikungunya, yellow fever, zika, and filariasis; as well as their agronomic impact on numerous crops. Many bacteria are able to produce proteins that are active against insect species. These bacteria include Bacillus thuringiensis, the most widely-studied pesticidal bacterium, which synthesizes proteins that accumulate in crystals with insecticidal properties and which has been widely used in the biological control of insects from different orders, including Lepidoptera, Coleoptera, and Diptera. In this review, we summarize all the bacterial proteins, from B. thuringiensis and other entomopathogenic bacteria, which have described insecticidal activity against dipteran pests, including species of medical and agronomic importance.
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A patent review on strategies for biological control of mosquito vector. World J Microbiol Biotechnol 2020; 36:187. [DOI: 10.1007/s11274-020-02960-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/07/2020] [Indexed: 12/31/2022]
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Dacey DP, Chain FJJ. The Challenges of Microbial Control of Mosquito-Borne Diseases Due to the Gut Microbiome. Front Genet 2020; 11:504354. [PMID: 33133140 PMCID: PMC7575760 DOI: 10.3389/fgene.2020.504354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 09/18/2020] [Indexed: 01/09/2023] Open
Abstract
Mosquitoes are one of the deadliest animals on earth because of their ability to transmit a wide range of human pathogens. Traditional mosquito control methods use chemical insecticides, but with dwindling long-term effectiveness and negative effects on the environment, microbial forms of control have become common alternatives. The insecticide Bacillus thuringiensis subspecies israelensis (Bti) is the most popular of these alternatives, although it can also have direct effects on lowering environmental biodiversity and indirect effects on food-web relationships in the ecosystems where it is deployed. In addition, microbial control agents that impede pathogen development or transmission from mosquito to human are under investigation, including Wolbachia and Asaia, but unexpected interactions with mosquito gut bacteria can hinder their effectiveness. Improved characterization of mosquito gut bacterial communities is needed to determine the taxa that interfere with microbial controls and their effectiveness in wild populations. This mini-review briefly discusses relationships between mosquito gut bacteria and microbial forms of control, and the challenges in ensuring their success.
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Affiliation(s)
- Daniel P Dacey
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, United States
| | - Frédéric J J Chain
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, United States
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Dahmana H, Raoult D, Fenollar F, Mediannikov O. Insecticidal Activity of Bacteria from Larvae Breeding Site with Natural Larvae Mortality: Screening of Separated Supernatant and Pellet Fractions. Pathogens 2020; 9:pathogens9060486. [PMID: 32570965 PMCID: PMC7350308 DOI: 10.3390/pathogens9060486] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/12/2020] [Accepted: 06/17/2020] [Indexed: 01/15/2023] Open
Abstract
Mosquitoes can transmit to humans devastating and deadly pathogens. As many chemical insecticides are banned due to environmental side effects or are of reduced efficacy due to resistance, biological control, including the use of bacterial strains with insecticidal activity, is of increasing interest and importance. The urgent actual need relies on the discovery of new compounds, preferably of a biological nature. Here, we explored the phenomenon of natural larvae mortality in larval breeding sites to identify potential novel compounds that may be used in biological control. From there, we isolated 14 bacterial strains of the phylum Firmicutes, most of the order Bacillales. Cultures were carried out under controlled conditions and were separated on supernatant and pellet fractions. The two fractions and a 1:1 mixture of the two fractions were tested on L3 and early L4 Aedes albopictus. Two concentrations were tested (2 and 6 mg/L). Larvae mortality was recorded at 24, 48 and 72 h and compared to that induced by the commercialized B. thuringiensis subsp. israelensis. Of the 14 strains isolated, 11 were active against the A. albopictus larvae: 10 of the supernatant fractions and one pellet fraction, and mortality increased with the concentration. For the insecticide activity prediction in three strains of the Bacillus cereus complex, PCR screening of the crystal (Cry) and cytolytic (Cyt) protein families characteristic to B. thuringiensis subsp. israelensis was performed. Most of the genes coding for these proteins' synthesis were not detected. We identified bacterial strains that exhibit higher insecticidal activity compared with a commercial product. Further studies are needed for the characterization of active compounds.
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Affiliation(s)
- Handi Dahmana
- IRD, AP-HM, MEPHI, Aix Marseille University, 13005 Marseille, France; (H.D.); (D.R.)
- IHU-Méditerranée Infection, 13005 Marseille, France;
| | - Didier Raoult
- IRD, AP-HM, MEPHI, Aix Marseille University, 13005 Marseille, France; (H.D.); (D.R.)
- IHU-Méditerranée Infection, 13005 Marseille, France;
| | - Florence Fenollar
- IHU-Méditerranée Infection, 13005 Marseille, France;
- IRD, AP-HM, SSA, VITROME, Aix Marseille University, 13005 Marseille, France
| | - Oleg Mediannikov
- IRD, AP-HM, MEPHI, Aix Marseille University, 13005 Marseille, France; (H.D.); (D.R.)
- IHU-Méditerranée Infection, 13005 Marseille, France;
- Correspondence: ; Tel.: +33-(0)4-13-73-24-01; Fax: +33-(0)4-13-73-24-02
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Pires S, Alves J, Dia I, Gómez LF. Susceptibility of mosquito vectors of the city of Praia, Cabo Verde, to Temephos and Bacillus thuringiensis var israelensis. PLoS One 2020; 15:e0234242. [PMID: 32520941 PMCID: PMC7286513 DOI: 10.1371/journal.pone.0234242] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 05/21/2020] [Indexed: 11/18/2022] Open
Abstract
Many vector-borne diseases circulate in the Republic of Cabo Verde. These include malaria during the colonization of the archipelago by the Portuguese explorers and several arboviruses such as yellow fever (now eradicated), dengue and zika. To control these vector-borne diseases, an integrated vector control program was implemented. The main targeted mosquito vectors are Aedes aegypti and Anopheles arabiensis, and in a lesser extent the potential arbovirus vector Culex pipiens s.l. The main control strategy is focused on mosquito aquatic stages using diesel oil and Temephos. This latter has been applied in Cabo Verde since 1979. Its continuous use was followed by the emergence of resistance in mosquito populations. We investigated the current susceptibility to Temephos of the three potential mosquito vectors of Cabo Verde through bioassays tests. Our results showed various degrees of susceptibility with 24h post-exposure mortality rates ranging from 43.1% to 90.9% using WHO diagnostic doses. A full susceptibility was however observed with Bacillus thurigiensis var israelensis with mortality rates from 99.6% to 100%.
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Affiliation(s)
- Sílvia Pires
- Unidade de Ciências da Natureza, da Vida e do Ambiente, Universidade Jean Piaget de Cabo Verde, Praia, Cabo Verde
| | - Joana Alves
- Instituto Nacional de Saúde Pública, Ministério da Saúde, Praia, Cabo Verde
| | - Ibrahima Dia
- Unité d’entomologie médicale, Institut Pasteur de Dakar, Dakar, Senegal
| | - Lara F. Gómez
- Unidade de Ciências da Natureza, da Vida e do Ambiente, Universidade Jean Piaget de Cabo Verde, Praia, Cabo Verde
- * E-mail:
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Goje LJ, Elmi ED, Bracuti A, Courty T, Rao T, Alzahrani FA, Crickmore N. Identification of Aedes aegypti specificity motifs in the N-terminus of the Bacillus thuringiensis Cry2Aa pesticidal protein. J Invertebr Pathol 2020; 174:107423. [PMID: 32525026 DOI: 10.1016/j.jip.2020.107423] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/21/2020] [Accepted: 06/04/2020] [Indexed: 10/24/2022]
Abstract
One advantage of using the Cry proteins of Bacillus thuringiensis as pesticides is their relatively narrow spectrum of activity, thus reducing the risk of non-target effects. Understanding the molecular basis of specificity has the potential to help us design improved products against emerging pests, or against pests that have developed resistance to other Cry proteins. Many previous studies have associated specificity with the binding of the Cry protein, particularly through the apical regions of domain II, to particular receptors on the midgut epithelial cells of the host insect. We have previously found that the specificity of Cry2A proteins against some insects is associated with domain I, which is traditionally associated with pore-formation but not receptor binding. In this work we identify four amino acids in the N-terminal region that, when mutated, can confer activity towards Aedes aegypti to Cry2Ab, a protein known to lack this toxicity. Intriguingly these amino acids are located in the region (amino acids 1-49) that is believed to be removed during proteolytic activation of the Cry protein. We discuss how the motifs containing these amino acids might be involved in the toxic process.
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Affiliation(s)
| | - Elmi Dahir Elmi
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Anthony Bracuti
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Thomas Courty
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Tejas Rao
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | | | - Neil Crickmore
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK.
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The Cytocidal Spectrum of Bacillus thuringiensis Toxins: From Insects to Human Cancer Cells. Toxins (Basel) 2020; 12:toxins12050301. [PMID: 32384723 PMCID: PMC7291302 DOI: 10.3390/toxins12050301] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/27/2020] [Accepted: 05/02/2020] [Indexed: 12/29/2022] Open
Abstract
Bacillus thuringiensis (Bt) is a ubiquitous bacterium in soils, insect cadavers, phylloplane, water, and stored grain, that produces several proteins, each one toxic to different biological targets such as insects, nematodes, mites, protozoa, and mammalian cells. Most Bt toxins identify their particular target through the recognition of specific cell membrane receptors. Cry proteins are the best-known toxins from Bt and a great amount of research has been published. Cry are cytotoxic to insect larvae that affect important crops recognizing specific cell membrane receptors such as cadherin, aminopeptidase-N, and alkaline phosphatase. Furthermore, some Cry toxins such as Cry4A, Cry4B, and Cry11A act synergistically with Cyt toxins against dipteran larvae vectors of human disease. Research developed with Cry proteins revealed that these toxins also could kill human cancer cells through the interaction with specific receptors. Parasporins are a small group of patented toxins that may or may not have insecticidal activity. These proteins could kill a wide variety of mammalian cancer cells by recognizing specific membrane receptors, just like Cry toxins do. Surface layer proteins (SLP), unlike the other proteins produced by Bt, are also produced by most bacteria and archaebacteria. It was recently demonstrated that SLP produced by Bt could interact with membrane receptors of insect and human cancer cells to kill them. Cyt toxins have a structure that is mostly unrelated to Cry toxins; thereby, other mechanisms of action have been reported to them. These toxins affect mainly mosquitoes that are vectors of human diseases like Anopheles spp (malaria), Aedes spp (dengue, zika, and chikungunya), and Culex spp (Nile fever and Rift Valley fever), respectively. In addition to the Cry, Cyt, and parasporins toxins produced during spore formation as inclusion bodies, Bt strains also produce Vip (Vegetative insecticidal toxins) and Sip (Secreted insecticidal proteins) toxins with insecticidal activity during their vegetative growth phase.
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Dahmana H, Mediannikov O. Mosquito-Borne Diseases Emergence/Resurgence and How to Effectively Control It Biologically. Pathogens 2020; 9:E310. [PMID: 32340230 PMCID: PMC7238209 DOI: 10.3390/pathogens9040310] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/28/2022] Open
Abstract
Deadly pathogens and parasites are transmitted by vectors and the mosquito is considered the most threatening vector in public health, transmitting these pathogens to humans and animals. We are currently witnessing the emergence/resurgence in new regions/populations of the most important mosquito-borne diseases, such as arboviruses and malaria. This resurgence may be the consequence of numerous complex parameters, but the major cause remains the mismanagement of insecticide use and the emergence of resistance. Biological control programmes have rendered promising results but several highly effective techniques, such as genetic manipulation, remain insufficiently considered as a control mechanism. Currently, new strategies based on attractive toxic sugar baits and new agents, such as Wolbachia and Asaia, are being intensively studied for potential use as alternatives to chemicals. Research into new insecticides, Insect Growth Regulators, and repellent compounds is pressing, and the improvement of biological strategies may provide key solutions to prevent outbreaks, decrease the danger to at-risk populations, and mitigate resistance.
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Affiliation(s)
- Handi Dahmana
- Aix Marseille Univ, IRD, AP-HM, MEPHI, 13005 Marseille, France;
- IHU-Méditerranée Infection, 13005 Marseille, France
| | - Oleg Mediannikov
- Aix Marseille Univ, IRD, AP-HM, MEPHI, 13005 Marseille, France;
- IHU-Méditerranée Infection, 13005 Marseille, France
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Svobodová Z, Skoková Habuštová O, Spitzer L, Sehnal F. Importance of functional classification in the use of carabids for the environmental risk assessment of the GE crops and other agricultural practices. INSECT SCIENCE 2020; 27:375-388. [PMID: 30260074 DOI: 10.1111/1744-7917.12643] [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: 05/20/2018] [Revised: 08/20/2018] [Accepted: 09/17/2018] [Indexed: 06/08/2023]
Abstract
Carabids (Coleoptera: Carabidae) seem to be suitable bioindicators of the environmental impacts of novel agrotechnologies, including deployment of the genetically engineered (GE) crops. In this article, we describe our effort to employ carabids in the environmental risk assessment (ERA). GE maize MON88017, its near-isogenic hybrid nontreated or treated with the soil insecticide chlorpyrifos, and two reference hybrids were used to compare three different ways how to utilize carabids in ERA. The analysis of abundance of all captured carabids or of the most abundant carabid species did not disclose any differences between the treatments. The analysis based on the categories of functional traits revealed distinct features of some treatments and proved suitable for ERA because it permitted field data transportability in spite of different species compositions. Our results indicate that GE maize has no detrimental environmental effect. On the other hand, we found significant trends toward lower abundance and lower species number (including analysis of all carabid species together) in plots treated with the insecticide, and some tendencies to higher abundance and higher species number in plots sown with the reference hybrid PR38N86. Using functional group indicators allows identification of unintended changes in ecological functions of agroecosystem and comparability across geographies. We recommend data evaluation at the level of the categories of functional traits in ERA of GE crops and other agricultural practices.
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Affiliation(s)
- Zdeňka Svobodová
- Czech Academy of Sciences, Biology Centre, Institute of Entomology, České Budějovice, Czech Republic
| | - Oxana Skoková Habuštová
- Czech Academy of Sciences, Biology Centre, Institute of Entomology, České Budějovice, Czech Republic
| | - Lukáš Spitzer
- Museum of the Moravian Wallachia Region, Vsetín, Czech Republic
| | - František Sehnal
- Czech Academy of Sciences, Biology Centre, Institute of Entomology, České Budějovice, Czech Republic
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30
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Viana JL, Soares-da-Silva J, Vieira-Neta MRA, Tadei WP, Oliveira CD, Abdalla FC, Peixoto CA, Pinheiro VCS. Isolates of Bacillus thuringiensis from Maranhão biomes with potential insecticidal action against Aedes aegypti larvae (Diptera, Culicidae). BRAZ J BIOL 2020; 81:114-124. [PMID: 32130286 DOI: 10.1590/1519-6984.223389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 10/23/2019] [Indexed: 11/22/2022] Open
Abstract
Entomopathogenic agents are viable and effective options due to their selective action against insects but benign effects on humans and the environment. The most promising entomopathogens include subspecies of Bacillus thuringiensis (Bt), which are widely used for the biological control of insects, including mosquito vectors of human pathogens. The efficacy of B. thuringiensis toxicity has led to the search for new potentially toxic isolates in different regions of the world. Therefore, soil samples from the Amazon, Cerrado and Caatinga biomes of the state of Maranhão were evaluated for their potential larvicidal action against Aedes aegypti. The isolates with high toxicity to mosquito larvae, as detected by bioassays, were subjected to histological evaluation under a light microscope to identify the genes potentially responsible for the toxicity. Additionally, the toxic effects of these isolates on the intestinal epithelium were assessed. In the new B. thuringiensis isolates toxic to A. aegypti larvae, cry and cyt genes were amplified at different frequencies, with cry4, cyt1, cry32, cry10 and cry11 being the most frequent (33-55%) among those investigated. These genes encode specific proteins toxic to dipterans and may explain the severe morphological changes in the intestine of A. aegypti larvae caused by the toxins of the isolates.
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Affiliation(s)
- J L Viana
- Programa de Pós-graduação em Biodiversidade e Biotecnologia da Rede BIONORTE - PPG BIONORTE, Universidade do Estado do Amazonas - UEA, Av. Carvalho Leal, 1777, Ed. Anexo, 4º andar, Cachoeirinha, CEP 69065-00, Manaus, AM, Brasil.,Laboratório de Entomologia Médica, Programa de Pós-graduação em Biodiversidade, Ambiente e Saúde, Centro de Estudos Superiores de Caxias - CESC, Universidade Estadual do Maranhão - UEMA, Praça Duque de Caxias, Morro do Alecrim, s/n, CEP 65604-380, Caxias, MA, Brasil
| | - J Soares-da-Silva
- Coordenação de Ciências Naturais/Biologia, Universidade Federal do Maranhão - UFMA, Campus VII, Av. Dr. José Anselmo, 2008, São Sebastião, CEP 65400-000, Codó, MA, Brasil
| | - M R A Vieira-Neta
- Universidade Federal de São Carlos - UFSCar, Campus Sorocaba, Rodovia João Leme dos Santos, SP-264, Km 110, Itinga, CEP 18052-780, Sorocaba, SP, Brasil
| | - W P Tadei
- Programa de Pós-graduação em Entomologia, Laboratório de Malária e Dengue, Instituto Nacional de Pesquisas da Amazônia - INPA, Av. André Araújo, 2936, Petrópolis, CEP 69067-375, Manaus, AM, Brasil
| | - C D Oliveira
- Grupo Mosquitos Vetores: Endosimbionte e Interação Patógeno Vetor, Centro de Pesquisa René Rachou, Av. Augusto de Lima, 1715, Barro Preto, CEP 30190-002, Belo Horizonte, MG, Brasil
| | - F C Abdalla
- Laboratório de Biologia Estrutural e Funcional - LABEF, Universidade Federal de São Carlos - UFSCar, Campus Sorocaba, Rodovia João Leme dos Santos, SP-264, Itinga, CEP 18052-780, Sorocaba, SP, Brasil
| | - C A Peixoto
- Laboratório de Ultraestrutura, Instituto de Pesquisas Aggeu Magalhães, Fundação Oswaldo Cruz - FIOCRUZ, Av. Moraes Rego, s/n, Campus UFPE, Cidade Universitária, CEP 50740-465, Recife, PE, Brasil
| | - V C S Pinheiro
- Laboratório de Entomologia Médica, Departamento de Química e Biologia, Centro de Estudos Superiores de Caxias - CESC, Universidade Estadual do Maranhão - UEMA, Praça Duque de Caxias, s/n, Morro do Alecrim, CEP 65604-380, Caxias, MA, Brasil
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Chen J, Aimanova KG, Gill SS. Aedes cadherin receptor that mediates Bacillus thuringiensis Cry11A toxicity is essential for mosquito development. PLoS Negl Trop Dis 2020; 14:e0007948. [PMID: 32012156 PMCID: PMC7018227 DOI: 10.1371/journal.pntd.0007948] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 02/13/2020] [Accepted: 11/25/2019] [Indexed: 11/20/2022] Open
Abstract
Aedes cadherin (AaeCad, AAEL024535) has been characterized as a receptor for Bacillus thuringiensis subsp. israelensis (Bti) Cry11A toxins. However, its role in development is still unknown. In this study, we modified the cadherin gene using ZFN and TALEN. Even though we obtained heterozygous deletions, no homozygous mutants were viable. Because ZFN and TALEN have lower off-targets than CRISPR/Cas9, we conclude the cadherin gene is essential for Aedes development. In contrast, in lepidopteran insects loss of a homologous cadherin does not appear to be lethal, since homozygous mutants are viable. To analyze the role of AaeCad in vivo, we tagged this protein with EGFP using CRISPR-Cas9-mediated homologous recombination and obtained a homozygous AaeCad-EGFP line. Addition of Aedes Rad51 mRNA enhanced the rate of recombination. We then examined AaeCad protein expression in most tissues and protein dynamics during mosquito development. We observe that AaeCad is expressed in larval and adult midgut-specific manner and its expression pattern changed during the mosquito development. Confocal images showed AaeCad has high expression in larval caecae and posterior midgut, and also in adult midgut. Expression of AaeCad is observed primarily in the apical membranes of epithelial cells, and not in cell-cell junctions. The expression pattern observed suggests AaeCad does not appear to play a role in these junctions. However, we cannot exclude its role beyond cell-cell adhesion in the midgut. We also observed that Cry11A bound to the apical side of larval gastric caecae and posterior midgut cells exactly where AaeCad-EGFP was expressed. Their co-localization suggests that AaeCad is indeed a receptor for the Cry11A toxin. Using this mosquito line we also observed that low doses of Cry11A toxin caused the cells to slough off membranes, which likely represents a defense mechanism, to limit cell damage from Cry11A toxin pores formed in the cell membrane. A number of receptors for Bt Cry toxins, have been identified and characterized, including cadherin proteins. However, the role of these proteins in the insect is unknown and there have been few efforts to elucidate their function. First, in this study we show that in the mosquito, Aedes aegypti, the cadherin protein is essential for development. Secondly, we provide evidence that AaeCad plays a role in the apical membrane and the maintenance of midgut integrity by gene tagging using CRISPR/Cas9, which overcomes the limitation of receptor localization using antibodies in previous studies. These investigations are helpful to further investigate the physiological function of AaeCad. Moreover, this study demonstrated successful tagging of an essential gene with fluorescence protein in a non-model insect. In addition, this study showed that epithelium thinning is possibly a conserved mechanism for host defense against pore-forming toxins, like Cry11A.
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Affiliation(s)
- Jianwu Chen
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, United States of America
| | - Karly G. Aimanova
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, United States of America
| | - Sarjeet S. Gill
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, United States of America
- * E-mail:
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32
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Foxi C, Delrio G, Luciano P, Mannu R, Ruiu L. Comparative laboratory and field study of biorational insecticides for Culicoides biting midge management in larval developmental sites. Acta Trop 2019; 198:105097. [PMID: 31325415 DOI: 10.1016/j.actatropica.2019.105097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 07/16/2019] [Accepted: 07/16/2019] [Indexed: 12/24/2022]
Abstract
An appropriate management strategy of bluetongue vectors should include larvicidal treatments in their larval development sites utilizing active substances with low environmental impact. A selection of biorational insecticides with potential against dipteran larvae was assayed in the laboratory against field collected Culicoides larvae including C. cataneii, C. circumscriptus, and C. imicola, determining their median lethal concentrations in water and mud/water substrate. The efficacy of formulations containing the insect growth regulators pyriproxyfen and cyromazine, the botanical insecticide azadirachtin, and the entomopathogenic bacteria Bacillus thuringiensis israelensis and Brevibacillus laterosporus, was also assessed in field conditions in a comparative study conducted in sheep farm larval development sites, including treatments with the organophosphate temephos. Significant larvicidal properties were associated with the various insecticides evaluated in the laboratory assays and in field trials, although with different levels of effectiveness. While temephos was confirmed to be an effective broad spectrum larvicidal substance, B. laterosporus appeared to be the most effective among entomopathogens, while insect growth regulators combined a good efficacy to a long-lasting residual effect in the field. Everything considered, the use of these biorational insecticides alone or in combination with larval habitat manipulation techniques appears to be a promising method to complement integrated biting midge management programs.
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33
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Zhao GH, Liu JN, Hu XH, Batool K, Jin L, Wu CX, Wu J, Chen H, Jiang XY, Yang ZH, Huang XH, Huang EJ, Yu XQ, Guan X, Zhang LL. Cloning, expression and activity of ATP-binding protein in Bacillus thuringiensis toxicity modulation against Aedes aegypti. Parasit Vectors 2019; 12:319. [PMID: 31238963 PMCID: PMC6593554 DOI: 10.1186/s13071-019-3560-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 06/09/2019] [Indexed: 11/17/2022] Open
Abstract
Background Bacillus thuringiensis israelensis (Bti) is a widely used mosquitocidal microbial pesticide due to its high toxicity. ATP-binding proteins (ABP) are prevalently detected in insects and are related to reaction against Bti toxins. However, the function of ABP in mosquito biocontrol is little known, especially in Aedes aegypti. Therefore, this study aimed to clarify the function of ABP in Ae. aegypti against Bti toxin. Results Aedes aegypti ABP (GenBank: XM_001661856.2) was cloned, expressed and purified in this study. Far-western blotting and ELISA were also carried out to confirm the interaction between ABP and Cry11Aa. A bioassay of Cry11Aa was performed both in the presence and absence of ABP, which showed that the mortality of Ae. aegypti is increased with an increase in ABP. Conclusions Our results suggest that ABP in Ae. aegypti can modulate the toxicity of Cry11Aa toxin to mosquitoes by binding to Bti toxin. This could not only enrich the mechanism of Bt toxin, but also provide more data for the biocontrol of this transmission vector.
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Affiliation(s)
- Guo-Hui Zhao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jian-Nan Liu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xiao-Hua Hu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Khadija Batool
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Liang Jin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Chen-Xu Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Juan Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Hong Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xiao-Yan Jiang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhao-Hui Yang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xian-Hui Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - En-Jiong Huang
- Fujian International Travel HealthCare Center, Fuzhou, 350001, China
| | - Xiao-Qiang Yu
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou, 510631, China.,Division of Cell Biology and Biophysics, University of Missouri-Kansas City, Kansas City, MO, 64110, USA
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Ling-Ling Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
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de Bortoli CP, Jurat-Fuentes JL. Mechanisms of resistance to commercially relevant entomopathogenic bacteria. CURRENT OPINION IN INSECT SCIENCE 2019; 33:56-62. [PMID: 31358196 DOI: 10.1016/j.cois.2019.03.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/21/2019] [Accepted: 03/27/2019] [Indexed: 05/29/2023]
Abstract
Bacteria represent the most commercially successful entomopathogenic microbial group, with most commercialized insecticides containing gram-positive bacteria in the Bacillaceae family. Resistance to entomopathogenic bacteria threatens sustainable agriculture, and information on the mechanisms and genes involved is vital to develop management practices aimed at reducing this risk. We provide an integrative summary on mechanisms responsible for resistance to commercialized entomopathogenic bacteria, including information on resistance to transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt crops). The available experimental evidence identifies alterations in binding of insecticidal proteins to receptors in the host as the main mechanism for high levels of resistance to entomopathogenic bacteria.
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Affiliation(s)
| | - Juan Luis Jurat-Fuentes
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996, United States.
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Gillis A, Fayad N, Makart L, Bolotin A, Sorokin A, Kallassy M, Mahillon J. Role of plasmid plasticity and mobile genetic elements in the entomopathogen Bacillus thuringiensis serovar israelensis. FEMS Microbiol Rev 2018; 42:829-856. [PMID: 30203090 PMCID: PMC6199540 DOI: 10.1093/femsre/fuy034] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 09/06/2018] [Indexed: 12/14/2022] Open
Abstract
Bacillus thuringiensis is a well-known biopesticide that has been used for more than 80 years. This spore-forming bacterium belongs to the group of Bacillus cereus that also includes, among others, emetic and diarrheic pathotypes of B. cereus, the animal pathogen Bacillus anthracis and the psychrotolerant Bacillus weihenstephanensis. Bacillus thuringiensis is rather unique since it has adapted its lifestyle as an efficient pathogen of specific insect larvae. One of the peculiarities of B. thuringiensis strains is the extent of their extrachromosomal pool, with strains harbouring more than 10 distinct plasmid molecules. Among the numerous serovars of B. thuringiensis, 'israelensis' is certainly emblematic since its host spectrum is apparently restricted to dipteran insects like mosquitoes and black flies, vectors of human and animal diseases such as malaria, yellow fever, or river blindness. In this review, the putative role of the mobile gene pool of B. thuringiensis serovar israelensis in its pathogenicity and dedicated lifestyle is reviewed, with specific emphasis on the nature, diversity, and potential mobility of its constituents. Variations among the few related strains of B. thuringiensis serovar israelensis will also be reported and discussed in the scope of this specialised insect pathogen, whose lifestyle in the environment remains largely unknown.
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Affiliation(s)
- Annika Gillis
- Laboratory of Food and Environmental Microbiology, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Nancy Fayad
- Laboratory of Food and Environmental Microbiology, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
- Laboratory of Biodiversity and Functional Genomics (BGF), Faculty of Sciences, Université Saint-Joseph, 1107 2050 Beirut, Lebanon
| | - Lionel Makart
- Laboratory of Food and Environmental Microbiology, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Alexander Bolotin
- UMR1319 Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, F-78350 Jouy-en-Josas, France
| | - Alexei Sorokin
- UMR1319 Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, F-78350 Jouy-en-Josas, France
| | - Mireille Kallassy
- Laboratory of Biodiversity and Functional Genomics (BGF), Faculty of Sciences, Université Saint-Joseph, 1107 2050 Beirut, Lebanon
| | - Jacques Mahillon
- Laboratory of Food and Environmental Microbiology, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
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Florez AM, Suarez-Barrera MO, Morales GM, Rivera KV, Orduz S, Ochoa R, Guerra D, Muskus C. Toxic Activity, Molecular Modeling and Docking Simulations of Bacillus thuringiensis Cry11 Toxin Variants Obtained via DNA Shuffling. Front Microbiol 2018; 9:2461. [PMID: 30386315 PMCID: PMC6199390 DOI: 10.3389/fmicb.2018.02461] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 09/25/2018] [Indexed: 11/23/2022] Open
Abstract
The Cry11 family belongs to a large group of δ-endotoxins that share three distinct structural domains. Among the dipteran-active toxins referred to as three-domain Cry11 toxins, the Cry11Aa protein from Bacillus thuringiensis subsp. israelensis (Bti) has been the most extensively studied. Despite the potential of Bti as an effective biological control agent, the understanding of Cry11 toxins remains incomplete. In this study, five Cry11 variants obtained via DNA shuffling displayed toxic activity against Aedes aegypti and Culex quinquefasciatus. Three of these Cry11 variants (8, 23, and 79) were characterized via 3D modeling and analysis of docking with ALP1. The relevant mutations in these variants, such as deletions, insertions and point mutations, are discussed in relation to their structural domains, toxic activities and toxin-receptor interactions. Importantly, deletion of the N-terminal segment in domain I was not associated with any change in toxic activity, and domain III exhibited higher sequence variability than domains I and II. Variant 8 exhibited up to 3.78- and 6.09-fold higher toxicity to A. aegypti than Cry11Bb and Cry11Aa, respectively. Importantly, variant 79 showed an α-helix conformation at the C-terminus and formed crystals retaining toxic activity. These findings indicate that five Cry11 variants were preferentially reassembled from the cry11Aa gene during DNA shuffling. The mutations described in loop 2 and loop 3 of domain II provide valuable information regarding the activity of Cry11 toxins against A. aegypti and C. quinquefasciatus larvae and reveal new insights into the application of directed evolution strategies to study the genetic variability of specific domains in cry11 family genes.
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Affiliation(s)
- Alvaro Mauricio Florez
- RG Microbial Ecology: Metabolism, Genomics & Evolution, Microbiomas Foundation, Chía, Colombia
| | - Miguel Orlando Suarez-Barrera
- Laboratorio de Biología Molecular y Biotecnología, Universidad de Santander, Bucaramanga, Colombia.,Escuela de Medicina, Facultad de Salud, Universidad Industrial de Santander, Bucaramanga, Colombia
| | - Gloria M Morales
- Laboratorio de Biología Molecular y Biotecnología, Universidad de Santander, Bucaramanga, Colombia
| | - Karen Viviana Rivera
- Laboratorio de Biología Molecular y Biotecnología, Universidad de Santander, Bucaramanga, Colombia
| | - Sergio Orduz
- Grupo Biologa Funcional, Laboratorio de Prospección y Diseo de Biomoléculas, Escuela de Biociencias, Universidad Nacional, Sede Medellín, Colombia
| | - Rodrigo Ochoa
- Programa de Estudio y Control de Enfermedades Tropicales PECET, Unidad de Biologa Molecular y Computacional-UBMC, Universidad de Antioquía, Medellín, Colombia
| | - Diego Guerra
- Programa de Estudio y Control de Enfermedades Tropicales PECET, Unidad de Biologa Molecular y Computacional-UBMC, Universidad de Antioquía, Medellín, Colombia
| | - Carlos Muskus
- Programa de Estudio y Control de Enfermedades Tropicales PECET, Unidad de Biologa Molecular y Computacional-UBMC, Universidad de Antioquía, Medellín, Colombia
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37
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Short SM, van Tol S, MacLeod HJ, Dimopoulos G. Hydrogen cyanide produced by the soil bacterium Chromobacterium sp. Panama contributes to mortality in Anopheles gambiae mosquito larvae. Sci Rep 2018; 8:8358. [PMID: 29844510 PMCID: PMC5974309 DOI: 10.1038/s41598-018-26680-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 05/04/2018] [Indexed: 11/09/2022] Open
Abstract
Mosquito larvae continuously encounter microbes in their aquatic environment, which serve as food and play a critical role in successful development. In previous work, we isolated a Chromobacterium sp. (C.sp_P) with larvicidal activity from the midgut of dengue vector Aedes mosquitoes in Panama. In this study, we found a positive correlation between initial concentrations of C.sp_P and larval mortality rates, and that C.sp_P is more efficient at inducing larval mortality in a high nutrient environment. Multiple Chromobacterium species induce larval mortality with similar efficacy to C.sp_P except for C. subtsugae. We also found that a non-lethal dose of C.sp_P lengthens development time and increases mortality over multiple developmental stages, suggesting persistent effects of exposure. Additionally, we showed that larvicidal activity persists in the larval breeding water after removal of live bacteria, and that the larvicidal factor in C.sp_P-treated water is smaller than 3 kDa, heat resistant to 90 °C, and lost after vacuum centrifugation. We showed that C.sp_P produces hydrogen cyanide in culture and in larval water at concentrations sufficient to kill An. gambiae larvae, and treatment of the larval water with a cyanide antidote eliminated larvicidal activity. We conclude that a potential mechanism by which C.sp_P can induce larval mortality is via production of hydrogen cyanide.
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Affiliation(s)
- Sarah M Short
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Sarah van Tol
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA.,Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Hannah J MacLeod
- 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.
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Bartholomay LC, Michel K. Mosquito Immunobiology: The Intersection of Vector Health and Vector Competence. ANNUAL REVIEW OF ENTOMOLOGY 2018; 63:145-167. [PMID: 29324042 DOI: 10.1146/annurev-ento-010715-023530] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
As holometabolous insects that occupy distinct aquatic and terrestrial environments in larval and adult stages and utilize hematophagy for nutrient acquisition, mosquitoes are subjected to a wide variety of symbiotic interactions. Indeed, mosquitoes play host to endosymbiotic, entomopathogenic, and mosquito-borne organisms, including protozoa, viruses, bacteria, fungi, fungal-like organisms, and metazoans, all of which trigger and shape innate infection-response capacity. Depending on the infection or interaction, the mosquito may employ, for example, cellular and humoral immune effectors for septic infections in the hemocoel, humoral infection responses in the midgut lumen, and RNA interference and programmed cell death for intracellular pathogens. These responses often function in concert, regardless of the infection type, and provide a robust front to combat infection. Mosquito-borne pathogens and entomopathogens overcome these immune responses, employing avoidance or suppression strategies. Burgeoning methodologies are capitalizing on this concerted deployment of immune responses to control mosquito-borne disease.
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Affiliation(s)
- Lyric C Bartholomay
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Wisconsin 53706;
| | - Kristin Michel
- Division of Biology, Kansas State University, Manhattan, Kansas 66506;
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