Banca de QUALIFICAÇÃO: EMILY MESQUITA DA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : EMILY MESQUITA DA SILVA
DATE: 16/09/2022
TIME: 09:00
LOCAL: Online (Plataforma Google Meet)
TITLE:

Influence of ticks' microbiota in the action of entomopathogenic fungi

KEY WORDS:

vector-borne diseases, biological control, bacteriome, Metarhizium anisopliae, 16S rRNA.

PAGES: 50
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

Ticks are obligate blood-sucking parasites responsible for significant economic losses and concerns with human and animal health, mainly due to the transmission of pathogens. Entomopathogenic fungi have been intensively studied as an alternative and possible ally to synthetic acaricides in the integrated control of ticks. For the qualification exam, we will present the first chapter of the dissertation where we investigated how the gut bacterial community of Rhipicephalus microplus is shaped after Metarhizium anisopliae treatment and the tick susceptibility to the fungus after disrupting gut bacterial microbiota. Partially engorged R. microplus females were artificially fed with pure bovine blood (CTR), or blood plus tetracycline (T). Two other groups received the same diet, only blood and plus tetracycline, and were topically treated with M. anisopliae (F) and (T+F) respectively. The guts of R. microplus were dissected, the genomic DNA was extracted three days after the treatment and the V3-V4 variable region of the bacterial 16S rRNA gene was amplified. The gut of ticks that did not receive the antibiotic and were treated with M. anisopliae (F) exhibited lower bacterial diversity and a higher occurrence of Coxiella spp. Simpson diversity index and Pileou equability coefficient were higher in the bacterial community of the guts when R. microplus were fed with tetracycline and fungus treated. Ticks from fungus-treated groups (with or without tetracycline) exhibited lower survival than untreated females. Feeding ticks previously with the antibiotic did not change their susceptibility to the fungus, suggesting that the micoacaricide action will not be impacted if the calf is under antibiotic therapy. Ehrlichia spp. was not detected in the gut of fungus-treated groups, supporting the hypothesis that entomopathogenic fungi can affect the life cycle of tick-borne pathogens. This is the first report of the entomopathogenic fungus effect on the tick-gut microbiota.

BANKING MEMBERS:
Presidente - 2221855 - PATRICIA SILVA GOLO
Interna - 3103478 - MARISTELA PECKLE PEIXOTO
Externo à Instituição - GUILHERME MARCONDES KLAFKE
Externa à Instituição - MARIANA GUEDES CAMARGO - UFRRJ