| Autor: |
Ribeiro-Silva CS; Departamento de Biociências e Tecnologia, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia 74690-900, Brazil., Muniz ER; Departamento de Biociências e Tecnologia, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia 74690-900, Brazil., Lima VH; Departamento de Biociências e Tecnologia, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia 74690-900, Brazil., Bernardo CC; Faculdade Integradas da América do Sul, Caldas Novas 74692-532, Brazil., Arruda W; Departamento de Histologia, Embriologia e Biologia Celular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia 74690-900, Brazil., Castro RN; Departamento de Química Orgânica, Instituto de Química, Universidade Federal Rural do Rio de Janeiro, Seropédica 23890-000, Brazil., Gôlo PS; Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica 23890-000, Brazil., Angelo IC; Departamento de Epidemiologia e Saúde Pública, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica 23890-000, Brazil., Fernandes ÉKK; Departamento de Biociências e Tecnologia, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia 74690-900, Brazil. |
| Abstrakt: |
The chemical composition of tick cuticles acts as a barrier to pathogens and may limit infection by entomopathogenic fungi. This study characterized the cuticular neutral lipids (NL) and hydrocarbons (HCs) of four ixodid ticks that are widely distributed in Brazil. HC extracts were analyzed by gas chromatography-mass spectrometry and used to challenge Beauveria bassiana IP361 and Metarhizium robertsii IP146; the effect of cuticular extracts in fungal growth were evaluated by disk diffusion and conidial viability assays. In addition, conidial germination on the tick cuticle was evaluated by scanning electron microscopy, and NL from ticks treated with fungi were assessed by thin layer chromatography. Six HCs were exclusively identified in Amblyomma sculptum . Additionally, cuticle extracts from Dermacentor nitens and A. sculptum inhibited the growth of M. robertsii IP146 and reduced conidial germination of B. bassiana IP361 to 70% and 49%, respectively; the same extracts also produced cytotoxic effects, with conidial death above 30% and 60%. Electron micrographs showed a delayed germination of conidia incubated for 48 h or 72 h on D. nitens and A. sculptum . The lipid profile of A. sculptum treated with fungi was not significantly altered; triacylglycerol was not detected in the cuticle extracts of any other tick species. Finally, A. sculptum and D. nitens cuticles have lipid components that may limit the development of M. robertsii. |
