Banca de DEFESA: ANNA CARLA ALBERTO DA SILVA
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.STUDENT : ANNA CARLA ALBERTO DA SILVA
DATE: 22/02/2022
TIME: 09:00
LOCAL: Plataforma Google Meet - On line
TITLE:
Association of exposure to Euphorbia milii var. hislopii and Angiostrongylus cantonensis infection (Chen, 1935) on the physiological and hemocytic response in Biomphalaria glabrata (Say, 1818)
KEY WORDS:
Mollusca, Nematoda, Comparative Physiology, Metabolism energy, Hemocytes.
PAGES: 157
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:
The snail Biomphalaria glabrata acts as an intermediate host for different parasitic helminths, among which the most relevant in the Brazilian territory is Schistosoma mansoni, causing schistosomiasis mansoni. However, other parasites, such as Angiostrongylus cantonensis, which causes eosinophilic meningitis, present an increasing potential risk of dissemination. Knowledge of the interactions of this parasite with its molluscan host is fundamental to profile the epidemiology of the disease and establish possible control strategies. The use of molluscicide is one of the measures recommended by the WHO for the control of schistosomiasis mansoni transmission, but only niclosamide has been marketed for this purpose. Several phytochemicals have been tested, but Euphorbia milii (syn. splendens) var. hislopii latex is the most studied, having been pointed out as the most promising for selective control of infected mollusks and with evidence of its schistosomostatic potential. However, there are no studies on the action of this phytochemical in mollusks infected with other parasitic helminths of medical and veterinary importance. Thus, the present study proposes to investigate the effects of Euphorbia milii var. hislopii latex on B. glabrata infected by A. cantonensis on reproductive parameters, hemocytic response, changes in carbohydrate and nitrogen metabolism. For this purpose, different experiments were performed 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 0.08 mg/L aqueous solution of lyophilized latex of E. milii for 24 hours. To analyze the action of the product on reproductive behavior, the following were checked: survival over four weeks, fecundity, fertility, histopathological analysis of the ovotestis and albumen gland. In the latter organ, the galactogen concentration was analyzed. To analyze the hemocyte response, the total count and characterization of circulating hemocytes in the hemolymph were performed. To evaluate the changes in carbohydrate metabolism (glucose and lactate dehydrogenase (LDH)), nitrogenous products (total proteins, urea, uric acid, alanine aminotransferase (ALT) and aspartate aminotransferase (AST)) in the snail hemolymph, the A15 automated biochemical analyzer (Biosystems®) was used. The content of organic acids (oxalic, lactic, succinic and pyruvic) was evaluated by high performance liquid chromatography (HPLC) analysis. The determination of glycogen in the cephalopedial mass and digestive gland was performed and expressed as mg glucose/g tissue fresh weight. The results showed that B. glabrata infected with A. cantonensis and exposed to E. milii var. hislopii latex, presents lower survival, possibly due to the high expenditure on reproductive investment. The stressing agents, A. cantonensis infection causes a significant process of parasite castration in B. glabrata. On the other hand, the exposure to E. milii var. hislopii latex in both groups exposed and not infected (E) and exposed after infection with A. cantonensis showed a marked compensatory process, evidencing the terminal investment, especially from 21 days of infection until the end of the study (28 days). The hemocyte response of B. glabrata infected by A. cantonensis was greater from the third week of infection, 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 reducing significantly (36.37%) the number of larvae (L3) recovered at the end of the experiment in group I+E in relation to group I.
BANKING MEMBERS:
Presidente - 1109555 - JAIRO PINHEIRO DA SILVA
Interna - 2221840 - MELISSA CARVALHO MACHADO DO COUTO CHAMBARELLI
Externa à Instituição - CLÉLIA CHRISTINA MELLO SILVA ALMEIDA COSTA - FIOCRUZ
Externa à Instituição - MARIANA GOMES LIMA - UFRRJ
Externa à Instituição - MARTA JÚLIA FARO DOS SANTOS COSTA - FIOCRUZ
Externo à Instituição - JOSÉ AUGUSTO ALBUQUERQUE DOS SANTOS - FIOCRUZ
Externa à Instituição - ESTER MARIA MOTA - FIOCRUZ