Banca de DEFESA: ANDRESSA APARECIDA DE LIMA REIS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : ANDRESSA APARECIDA DE LIMA REIS
DATA : 05/03/2020
HORA: 12:00
LOCAL: Sala Prof Laerte Grisi - LQEPV
TÍTULO:

Cellular characterization of hemolymph and evaluation of cell response after in vitro exposure to fluazuron from engorged females of Amblyomma sculptum

PALAVRAS-CHAVES:

hemocytes, ticks, benzoylphenylurea.

PÁGINAS: 63
GRANDE ÁREA: Ciências Agrárias
ÁREA: Medicina Veterinária
RESUMO:

Belonging to the Amblyomma cajennense complex, the tick Ambyomma sculptum can be found in the various regions of Brazil. It is known as star tick or horse tick and parasite domestic, wild and human animals, being the main transmitter of Rickettsia rickettsii etiological agent of Brazilian Spotted Fever. It has great importance in veterinary medicine because of several damages to its hosts, in addition to the suspicion of transmitting Theileria equi to horses. There are few active ingredients registered for the control of the A. sculptum tick. Fluazuron is an insect growth inhibitor used in the control of ticks that interferes with the arthropod's chitin production, preventing the phase change. The resistance of the tick population to antiparasitic agents represents an obstacle to control programs. Studies on the tick's immune system seek to assess changes in the hemolymphatic cellular response that make the immunology and physiology involved in the control and resistance mechanisms understand. The aim of this work was to characterize quantitatively and morphologically the hemocytes present in the hemolymph of engorged females of the A. sculptum tick and to evaluate the cellular immune response of this tick after in vitro exposure to fluazuron. For hemolymphatic cell characterization of A. sculptum. hemolymph was collected through a cuticle perforation in the dorsal part of the tick. The hemolymph was placed directly on a glass slide to make blood smears that were stained with Giemsa's solution. Differential hemocyte counting was performed based on the morphology observed in an optical microscope in 1000-fold magnification, by identifying the first 100 cells found in the stained smear. The evaluation of cell sizes and their components was performed by reading the slides made for differential counting of hemocytes with the aid of an Olympus optical microscope model BX51 with polarized light, coupled to a camera of the same brand model UC30. The total hemocyte count was performed with the aid of an optical microscope and a Neubauer Chamber. To evaluate the cellular response after in vitro exposure to fluazuron, immersion tests were performed with the engorged females of A. sculptum in the control (with diluents only) and treated (7.81, 250 and 4000 ppm) groups. Hemolymph was collected for total and differential hemocyte counts at 24h and 48h after immersion. The cellular characterization revealed that the A. sculptum tick has an average of 1024 cells / μL and six cell types: prohemocytes, plasmatocytes, granulocytes, spherulocytes, adipohemocytes and oenocytoids that are distributed differently in the hemolymph, where granulocyte was the most frequent type. Fluazuron was able to make cellular changes in the tick A. sculptum promoting a decrease in total hemocytes at a concentration of 4000ppm after 48h as well as reducing the frequency of granulocytes and increasing the frequency of spherulocytes in the differential count.

MEMBROS DA BANCA:
Interna - 122.630.647-02 - BARBARA RAUTA DE AVELAR - UFRRJ
Presidente - 1173660 - FABIO BARBOUR SCOTT
Externo à Instituição - LICIUS DE SA FREIRE - FIPERJ
Externa à Instituição - LILIAN CRISTINA DE SOUSA OLIVEIRA BATISTA CIRNE - CESVA