Banca de QUALIFICAÇÃO: ANNA CARLA ALBERTO DA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ANNA CARLA ALBERTO DA SILVA
DATE: 13/01/2022
TIME: 09:00
LOCAL: PLATAFORMA GOOGLE MEET - ON LINE
TITLE:

Comparative physiology and hemocytic response of Biomphalaria glabrata (Say, 1818) infected by Angiostrongylus cantonensis (Chen, 1935) and/or exposed to latex of Euphorbia milii var. hislopii

KEY WORDS:

Mollusca, Nematoda, Comparative Physiology, Metabolism energy, Hemocytes.

PAGES: 102
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

The mollusc Biomphalaria glabrata acts as an intermediate host of different parasitic helminths, among them the most relevant in the Brazilian territory is Schistosoma mansoni, which causes schistosomiasis mansoni. However, other parasites, such as the Angiostrongylus cantonensis, which causes eosinophilic meningitis, poses an increasing potential risk of dissemination. The knowledge of the interactions of this parasite with its mollusc host are essential to draw the profile. disease and establish possible control strategies. The use of molluscicide is one of the measures recommended by the WHO to control the transmission of schistosomiasis mansoni, but only niclosamide has been marketed for this end. Several phytochemicals have been tested, but latex from Euphorbia milii (syn. splendens) var. hislopii is the most studied, having been pointed out as the most promising for selective control of infected molluscs and with evidence of its potential schistosomostatic. However, there are no studies on the action of this phytochemical in molluscs infected with other helminth parasites of diseases of medical and veterinary importance. Therefore, the present study proposes to investigate the effects of latex on
Euphorbia milii var. hislopii in B. glabrata infected by A. cantonensis on reproductive parameters, hemocytic response, changes in carbohydrate metabolism and nitrogenous products. For this, different experiments were carried out with B. glabrata specimens divided into the following groups: control (C), exposed (E), infected (I) and infected and exposed (I+E) at different time intervals (one day, seven days, 14 days, 21 days and 28 days). The experimental infection was with 1,000 L1 of A. cantonensis and exposure with an aqueous solution of 0.08 mg/L of lyophilized E. milii latex for 24 hours. For analysis of the action of the product on the reproductive behavior were verified: survival over four weeks, fecundity, fertility, histopathological analysis of the ovotest and the albumen gland. In this last organ, the concentration of galactogen was analyzed. For analysis of the hemocytic response, total count and characterization of circulating hemocytes in the hemolymph were performed. To evaluate changes in carbohydrate metabolism (glucose and lactate dehydrogenase (LDH)), nitrogen products (total protein, urea, uric acid, alanine aminotransferase (ALT) and aspartate aminotransferase (AST)) in mollusc hemolymph, a biochemical analyzer was used automated A15 (Biosystems®). The content of organic acids (oxalic, lactic, succinic and pyruvic) were evaluated by high performance liquid chromatography (HPLC) analysis. The determination of glycogen in the cephalopedic mass and digestive gland was performed and expressed in mg of glucose/g of tissue, fresh weight. The results showed that B. glabrata infected with A. cantonensis and exposed to the latex of E. milii var. hislopii, has a lower survival rate, possibly due to the high expenditure on reproductive investment. As stressors, infection by A. cantonensis causes a significant parasitic castration process in B. glabrata. Exposure to latex of E. milii var. hislopii both exposed and uninfected groups (E) and exposed after infection with A. cantonensis there is a marked compensatory process, showing the terminal investment, especially from 21 days of infection until the end of the study (28 days). The hemocytic response of B. glabrata infected by A. cantonensis was greater from the third week of infection onwards, when it is possible to observe the presence of (L3), possibly because these larvae are more invasive, generating granuloma-like formation. The phytochemical acted on infected B. glabrata significantly reducing (36.37%) the number of larvae (L3) recovered at the end of the experiment in group I+E compared to group I.

BANKING MEMBERS:
Presidente - 1109555 - JAIRO PINHEIRO DA SILVA
Interna - 2221840 - MELISSA CARVALHO MACHADO DO COUTO CHAMBARELLI
Externa à Instituição - ESTER MARIA MOTA - FIOCRUZ
Externa à Instituição - CLÉLIA CHRISTINA MELLO SILVA ALMEIDA COSTA - FIOCRUZ
Externa à Instituição - MARTA JÚLIA FARO DOS SANTOS COSTA - FIOCRUZ