Banca de DEFESA: GABRIELA FRIANI VIEIRA TREVISANO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : GABRIELA FRIANI VIEIRA TREVISANO
DATE: 15/12/2021
TIME: 13:00
LOCAL: Online na plataforma Zoom
TITLE:

Use of Metarhizium anisopliae s.l. to control in Biomphalaria glabrata the intermediate host of Schistosoma mansoni

KEY WORDS:

Schistosomiasis; Entomopathogenic fungi; Biological control;

PAGES: 61
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Saneamento Aplicado a Saúde do Homem
SUMMARY:

Schistosomiasis is a disease that affects approximately 200 million people worldwide. It is considered one of the Neglected Tropical Diseases, second only to malaria in morbidity. Schistosomiasis mansoni is a waterborne parasitic disease caused by the trematode S. mansoni and has as an intermediate host mollusks of the genus Biomphalaria. Snail control has been proposed as a measure to reduce and interrupt transmission of the disease, complementary to other strategies that focus mainly on large-scale population treatment. Part of this study focused on presenting a systematic review of published scientific papers on the biological control of Biomphalaria spp. intermediate hosts of schistosomiasis, presenting challenges and future perspectives. Forty-seven articles in total were analyzed, from 1945 to 2021. The countries with the most published papers were: France (08 papers), Brazil (08 papers), USA (06 papers), and Egypt (06 papers). Predation was the main type of biological control used. The decade with the highest number of studies between 2010-2019 with 14 articles, while the period from 2010 to 2019, a greater diversity of biological control agents was used. The latter, as mentioned above, particularly fungi and bacteria, have attracted the attention of researchers in the last ten years. These microbial agents may function as physiological, reproductive and/or epigenetic disruptors that can manipulate and/or influence the dynamics of the interaction between Biomphalaria and Schistosoma. This study also emphasized the experimental analysis of a biological control agent, aiming to evaluate the effects of Metarhizium anisopliae s.l. CG 347 against Biomphalaria glabrata. S. mansoni infected snails were exposed for 24 hours to the fungus and analyzed for the following aspects: snail survival, impact of M. anisopliae treatment on cercariae elimination, number of circulating hemocytes in the hemolymph, and histopathology. The uninfected and fungus-treated snails were analyzed for: survival, total protein concentration in the hemolymph and digestive gland, and number of circulating hemocytes in the hemolymph. There was no death of the mollusks after the treatment period, but a 20% reduction of the total protein content in the hemolymph was observed when compared to the water control. The shedding cercariae of S. mansoni was an impacted parameter, with a 32.7% reduction when the mollusks were treated with M. anisopliae. The infected group presented lower number of hemocytes and the group infected and exposed to M. anisopliae. Regarding the histopathology of the mollusks, the groups UNI + MA and INF + MA, presented the fungus inside the following organs esophagus, stomach and intestine. This study addressed the first report of reduced cercariae S. mansoni shedding after treatment of B. glabrata using an entomopathogenic fungus, M. anisopliae. However, further analyses with longer exposure times and different fungal propagules are recommended. However, we contribute by providing information that contributes to foster the biological, alternative, and sustainable control of schistosomiasis transmission. This fungus is a possible promising biological control agent that can contribute to limit the transmission of schistosomiasis. 

BANKING MEMBERS:
Presidente - 2221855 - PATRICIA SILVA GOLO
Interna - 2860277 - ISABELE DA COSTA ANGELO
Interno - 1109555 - JAIRO PINHEIRO DA SILVA
Externa ao Programa - 3241766 - MARIANA GUEDES CAMARGO
Externo à Instituição - JOSÉ AUGUSTO ALBUQUERQUE DOS SANTOS - FIOCRUZ
Externa à Instituição - MARTA JÚLIA FARO DOS SANTOS COSTA - FIOCRUZ
Externo à Instituição - RONALDO DE CARVALHO AUGUSTO