Banca de DEFESA: LUISA ANDRADE AZEVEDO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LUISA ANDRADE AZEVEDO
DATE: 18/12/2023
TIME: 09:00
LOCAL: https://meet.google.com/dse-abzc-bpz
TITLE:

Effect of entomopathogenic fungi on oviposition and lipid metabolism of Aedes aegypti.

KEY WORDS:

Entomopathogenic fungi, biological control, mosquitoes, ovarian morphology

PAGES: 57
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

The Aedes aegypti mosquito is of great importance in the epidemiological chain of arboviruses that affect Public Health. Thinking about resistance to chemical insecticides and more ecological control solutions, the use of entomopathogenic fungi is increasingly being studied as an alternative to control A. aegypti. This work investigated the effects of Metarhizium anisopliae and Beauveria bassiana on oviposition, ovarian morphology and lipid profile in the fat body and ovaries of females exposed to the fungi, in addition to investigating the antimicrobial activity in A. aegypti larvae challenged by these fungi. To evaluate the effect of fungal exposure on oviposition and ovary morphology, females 6 to 8 days post-emergence were fed with mouse blood and exposed or not to M. anisopliae CG 153 at a concentration of 107 conidia/mL for 24h. , with the following groups being formed: G1= exposed to the fungus minutes before feeding; G2= fed 24h before fungal exposure; G3= fed 24h after fungal exposure; CTR= exposed to 0.03% Tween 80 minutes before feeding. Ovaries were dissected at 0, 24, 48 and 72h and investigation was carried out by histopathology. No statistical difference was observed in the following parameters: number of engorged females in each group (P=0.6358); quantity of total eggs produced (P~0.5948); comparison between the quantity of eggs per female fed (P=0.3191); or the number of live mosquitoes at the end of the experiments (P=0.7507). The ovarian follicles of mosquitoes exposed to M. anisopliae CG153 showed loss of tissue architecture after 48 hours of treatment, with rupture of the follicular epithelium, reduction in the number of oocytes and changes in the morphology of nurse cells. To evaluate the effect of fungal exposure on the lipid profile, females (6-8 days post-emergence; N=45) were exposed to M. anisopliae CG 153 or B. bassiana CG 479 at a concentration of 107 conidia/mL or Tween 80 at 0.03%. After 24, 48 or 72 hours of exposure, the ovaries and fat body of the females were dissected for lipid extraction and subsequent analysis of neutral lipids by one-dimensional thin layer chromatography. There was no statistical difference in the fatty acid and cholesterol profile in the fat body (P=0.7705 and P~0.8365) and ovaries (P=0.9798 and P>0.9999) at the times observed after exposure. Groups of 700 second stage larvae were immersed in 700 mL of B. bassiana CG 479 suspension at a concentration of 106 conidia/mL or 0.03% Tween 80. After 16, 24, 40 and 48h of exposure, a pool of 60 larvae (N=240) were macerated to evaluate antimicrobial activity by performing an antibiogram on strains of Escherichia coli, Staphylococcus aureus and Pseudomonas sp. resistant and sensitive to beta-lactams. However, no antimicrobial activity was identified in larvae macerate even after 48 hours of exposure to B. bassiana CG 479. Therefore, further studies on the effects of M. anisopliae CG 153 and B. bassiana CG 479 isolates on larvae and females of A. aegypti must be carried out to better understand the fungus-host dynamics.

COMMITTEE MEMBERS:
Presidente - 2860277 - ISABELE DA COSTA ANGELO
Interna - 2221855 - PATRICIA SILVA GOLO
Externo à Instituição - EVERTON KORT KAMP - UFG
Externa à Instituição - MARIANA GUEDES CAMARGO - UFRRJ
Externo à Instituição - WENDELL MARCELO DE SOUZA PERINOTTO - UFRB