Entomopathogenic microorganisms for the control of vectors Diptera: molecular characterization, pathology and epidemiology

• Grant number: 12/23947-0
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2013
• End date: October 31, 2015
• Field of knowledge: Biological Sciences - Parasitology - Entomology and Malacology of Parasites and Vectors
• Principal Investigator: Carlos José Pereira da Cunha de Araújo Coutinho
• Grantee: Carlos José Pereira da Cunha de Araújo Coutinho
• Host Institution: Superintendência de Controle de Endemias (SUCEN). Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Associated researchers: Isabel Maria Vicente Guedes de Carvalho Mello

Abstract

The use of chemical insecticides in mosquito control has presented difficulties in using, especially in recent years, basically due the high cost of development of these synthetic compounds, the environmental damage due to non-specificity, persistence, operational risk and increasing resistance to these compounds. These difficulties have led to a major effort to the development and refinement of alternative safe and effective control, such as the use of mechanical and biological methods.Among biological methods stand out the use of biopesticides, because they offer advantages such as high specificity, biodegradable, low environmental impact, does not cause resistance in insects and has low operational risk. Microbial agents with real potential for large scale production are the bacteria of the genus Bacillus, particularly two promising species, which synthesize entomocidal toxins and stand out in control of insect vectors: Bacillus thuringiensis and Bacillus sphaericus.To assist in the characterization of entomopathogenic properties, there are techniques at molecular level, which may help in identifying new protein endotoxins in new strains of B. thuringiensis and other entomopathogenic bacteria, as techniques that identify the genes responsible for toxicity. Because of the high diversity of these agents found in mosquito larvae in the state of São Paulo, it is imperative to perform larger studies using these techniques to elucidate the possible agents with potential for use in integrated vector management.Another group of microbial agents that affect mosquitoes are the baculoviruses. These present as main features as virion envelope with rod-shaped, a circular double-stranded DNA. Insect viruses are the most studied, due to their role as biological pesticides, important vectors and gene expression in cells of invertebrates and vertebrates. They naturally infect only arthropods and are harmless to non-target invertebrates and vertebrates.Most Baculoviridae were isolated from Lepidoptera, but are also known in Hymenoptera, Diptera, Coleoptera, Neuroptera, Trichoptera and Crustacea. The basic knowledge and applied of the baculovirus is almost exclusively based on studies from Lepidoptera, with about a hundred isolates described (Martignoni & Iwai, 1986) and 16 named species. In contrast, in dipteran baculovirus isolates have been poorly described (Jehle et al., 2006) and most were reported in the family Culicidae, with a very low prevalence in natural populations, typically less than 1%. In the first report of dipteran baculovirus infection in the southern hemisphere, the phylogenetic analysis of partial genomic sequence of the genes lef-8 and pif-2 puts the virus identified in a separate clade of genera and Nucleopolyhedrovirus Granulovirus, this virus is classified in the genus Deltabaculovírus since it combines with the genomic sequence identified in Deltabaculovírus Culex nigripalpus, Culex nigripalpus nucleopolyhedrovirus (CuniNPV), however, more molecular analyzes are needed for a better classification of the virus identified in Culex quinquefasciatus.This study aims to isolate, identify and characterize, at molecular levels, pathogens of blackfly larvae and Culicidae with potential for use in vector control activities, especially viruses and bacteria in order to increase the supply of efficient tools to be explored as suppression agents in medical entomology (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

VICENTE GUEDES DE CARVALHO, ISABEL MARIA; LOPO DE QUEIROZ, ARTUR TRANCOSO; DE MORAES, ROSIANE BRITO; GIL, HELIO BENITES; ALVES, RAFAEL; PINTO VIVIANI, ANDREA DE BARROS; BECNEL, JAMES JOHN; PEREIRA DA CUNHA DE ARAUJO-COUTINHO, CARLOS JOSE. Description of microsporidia in simulids: molecular and morphological characterization of microsporidia in the larvae of Simulium pertinax Kollar (Diptera: Simuliidae). Revista da Sociedade Brasileira de Medicina Tropical, v. 47, n. 5, p. 624-631, SEP-OCT 2014. (12/23947-0)

GOMES CAVADOS, CLARA DE FATIMA; PIRES, EDER SOARES; CHAVES, JEANE QUINTANILHA; ALVAREZ, DANIELLE NUNES; GIL, HELIO BENITES; DE OLIVEIRA, IRIS BRAZ RIBEIRO; PINTO VIVIANI CUNHA, ANDREA DE BARROS; PEREIRA DA CUNHA DE ARAUJO-COUTINHO, CARLOS JOSE. Isolation and genetic characterization of Lysinibacillus sphaericus strains found in mosquito larvae (Diptera: Culicidae). RESEARCH AND REPORTS IN TROPICAL MEDICINE, v. 8, p. 17-20, 2017. (12/23947-0)