1
|
Falqueto SA, Pitaluga BF, de Sousa JR, Targanski SK, Campos MG, de Oliveira Mendes TA, da Silva GF, Silva DHS, Soares MA. Bacillus spp. metabolites are effective in eradicating Aedes aegypti (Diptera: Culicidae) larvae with low toxicity to non-target species. J Invertebr Pathol 2020; 179:107525. [PMID: 33383067 DOI: 10.1016/j.jip.2020.107525] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 12/14/2020] [Accepted: 12/23/2020] [Indexed: 11/18/2022]
Abstract
The growing spread of dengue, chikungunya and Zika viruses demand the development of new and environmentally safe control methods for their vector, the mosquito Aedes aegypti. This study aims to find novel larvicidal agents from mutualistic (endophytic and rhizospheric) or edaphic bacteria that have no action against non-target organisms. Eleven out of the 254 bacterial strains tested were able to kill Ae. aegypti larvae. Larvicidal activity did not depend on presence of cells, since culture supernatants or crude lipopeptide extracts (CLEs) killed the larvae. Bacillus safensis BacI67 and Bacillus paranthracis C21 supernatants were the best performing supernatants, displaying the lowest lethal concentrations (LC50 = 31.11 µL/mL and 45.84 µL/mL, respectively). Bacillus velezensis B64a and Bacillus velezensis B15 produced the best performing CLEs (LC50 = 0.11 mg/mL and 0.12 mg/mL, respectively). Mass spectrometry analysis of CLEs detected a mixture of surfactins, iturins, and fengycins. The samples tested were weakly- or non-toxic to mammalian cells (RAW 264.7 macrophages and VERO cells) and non-target organisms (Caenorhabditis elegans, Galleria mellonella, Scenedesmus obliquus, and Tetrahymena pyriformis) - especially B. velezensis B15 CLE. The biosynthetic gene clusters related to secondary metabolism identified by whole genome sequencing of the four best performing bacteria strains revealed clusters for bacteriocin, beta-lactone, lanthipeptide, non-ribosomal peptide synthetases, polyketide synthases (PKS), siderophores, T3PKS, type 1 PKS-like, terpenes, thiopeptides, and trans-AT-PKS. Purification of lipopeptides may clarify the mechanisms by which these extracts kill Ae. aegypti larvae.
Collapse
Affiliation(s)
- Silvia Altoé Falqueto
- Departamento de Botânica e Ecologia, Universidade Federal de Mato Grosso, Av. Fernando Corrêa da Costa 2367, 78060-900 Cuiabá, Brazil
| | - Bruno Faria Pitaluga
- Departamento de Botânica e Ecologia, Universidade Federal de Mato Grosso, Av. Fernando Corrêa da Costa 2367, 78060-900 Cuiabá, Brazil
| | - Janaína Rosa de Sousa
- Departamento de Botânica e Ecologia, Universidade Federal de Mato Grosso, Av. Fernando Corrêa da Costa 2367, 78060-900 Cuiabá, Brazil
| | - Sabrina Ketrin Targanski
- Departamento de Botânica e Ecologia, Universidade Federal de Mato Grosso, Av. Fernando Corrêa da Costa 2367, 78060-900 Cuiabá, Brazil
| | - Mateus Gandra Campos
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Viçosa, Brazil
| | | | | | - Dulce Helena Siqueira Silva
- Centro de Inovação em Biodiversidade e Fármacos, Instituto de Química, Universidade Estadual Paulista Júlio de Mesquita Filho, Araraquara, Brazil
| | - Marcos Antônio Soares
- Departamento de Botânica e Ecologia, Universidade Federal de Mato Grosso, Av. Fernando Corrêa da Costa 2367, 78060-900 Cuiabá, Brazil.
| |
Collapse
|
2
|
Souza RS, Diaz-Albiter HM, Dillon VM, Dillon RJ, Genta FA. Digestion of Yeasts and Beta-1,3-Glucanases in Mosquito Larvae: Physiological and Biochemical Considerations. PLoS One 2016; 11:e0151403. [PMID: 27007411 PMCID: PMC4805253 DOI: 10.1371/journal.pone.0151403] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/26/2016] [Indexed: 01/24/2023] Open
Abstract
Aedes aegypti larvae ingest several kinds of microorganisms. In spite of studies regarding mosquito digestion, little is known about the nutritional utilization of ingested cells by larvae. We investigated the effects of using yeasts as the sole nutrient source for A. aegypti larvae. We also assessed the role of beta-1,3-glucanases in digestion of live yeast cells. Beta-1,3-glucanases are enzymes which hydrolyze the cell wall beta-1,3-glucan polyssacharide. Larvae were fed with cat food (controls), live or autoclaved Saccharomyces cerevisiae cells and larval weight, time for pupation and adult emergence, larval and pupal mortality were measured. The presence of S. cerevisiae cells inside the larval gut was demonstrated by light microscopy. Beta-1,3-glucanase was measured in dissected larval samples. Viability assays were performed with live yeast cells and larval gut homogenates, with or without addition of competing beta-1,3-glucan. A. aegypti larvae fed with yeast cells were heavier at the 4th instar and showed complete development with normal mortality rates. Yeast cells were efficiently ingested by larvae and quickly killed (10% death in 2h, 100% in 48h). Larvae showed beta-1,3-glucanase in head, gut and rest of body. Gut beta-1,3-glucanase was not derived from ingested yeast cells. Gut and rest of body activity was not affected by the yeast diet, but head homogenates showed a lower activity in animals fed with autoclaved S. cerevisiae cells. The enzymatic lysis of live S. cerevisiae cells was demonstrated using gut homogenates, and this activity was abolished when excess beta-1,3-glucan was added to assays. These results show that live yeast cells are efficiently ingested and hydrolyzed by A. aegypti larvae, which are able to fully-develop on a diet based exclusively on these organisms. Beta-1,3-glucanase seems to be essential for yeast lytic activity of A. aegypti larvae, which possess significant amounts of these enzyme in all parts investigated.
Collapse
Affiliation(s)
- Raquel Santos Souza
- Laboratory of Insect Biochemistry and Physiology, Oswaldo Cruz Institute, FIOCRUZ, 4365 Brasil Av, Leonidas Deane Building, room 207, Manguinhos, Rio de Janeiro, Brazil, 21040–360
| | - Hector Manuel Diaz-Albiter
- Laboratory of Insect Biochemistry and Physiology, Oswaldo Cruz Institute, FIOCRUZ, 4365 Brasil Av, Leonidas Deane Building, room 207, Manguinhos, Rio de Janeiro, Brazil, 21040–360
| | - Vivian Maureen Dillon
- Institute of Integrative Biology, Biosciences Building, University of Liverpool, Crown Street, Liverpool, L69 7ZB, United Kingdom
| | - Rod J. Dillon
- Division of Biomedical and Life Sciences, Furness Building, Lancaster University, Bailrigg, Lancaster, LA1 4YG, United Kingdom
- National Institute of Science and Technology for Molecular Entomology, 373 Carlos Chagas Filho Av., Center for Health Science, Building D, Basement, room 5, Cidade Universitária, Rio de Janeiro, Brazil, 21941–590
| | - Fernando Ariel Genta
- Laboratory of Insect Biochemistry and Physiology, Oswaldo Cruz Institute, FIOCRUZ, 4365 Brasil Av, Leonidas Deane Building, room 207, Manguinhos, Rio de Janeiro, Brazil, 21040–360
- National Institute of Science and Technology for Molecular Entomology, 373 Carlos Chagas Filho Av., Center for Health Science, Building D, Basement, room 5, Cidade Universitária, Rio de Janeiro, Brazil, 21941–590
- * E-mail:
| |
Collapse
|
3
|
Suzuki MT, Lereclus D, Arantes OMN. Fate of Bacillus thuringiensis strains in different insect larvae. Can J Microbiol 2005; 50:973-5. [PMID: 15644915 DOI: 10.1139/w04-087] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In favorable conditions Bacillus thuringiensis spores germinate and vegetative cells multiply, whereas in unfavorable conditions Bacillus thuringiensis sporulates and produces insecticidal crystal proteins. The development of B. thuringiensis strains was investigated in the larvae of insects belonging to the orders Lepidoptera and Diptera. Bacillus thuringiensis strains able to kill the insects did not always multiply in cadavers. Strains with no specificity to kill the insect sometimes multiplied when the insects were killed mechanically. These results indicate that some insect larvae represent an environment that favors the germination of B. thuringiensis spores and the multiplication of vegetative cells; however, there was no correlation between the toxin specificity and the specificity of the host.
Collapse
Affiliation(s)
- Marise Tanaka Suzuki
- Centre of Biological Sciences, State University of Londrina, 86051-970 Londrina/PR, Brazil
| | | | | |
Collapse
|