Banca de DEFESA: DÉBORA AZEVEDO BORGES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : DÉBORA AZEVEDO BORGES
DATE: 30/03/2023
TIME: 14:00
LOCAL: Sala Prof Laerte Grisi - LQEPV
TITLE:

Fluazuron in the Control of the Tick Amblyomma sculptum: Efficacy, Pharmacokinetics and Palatability Using the Guinea Pig as Experimental Model

KEY WORDS:

Tick control, star tick, benzoylphenylureas.

PAGES: 130
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SUMMARY:

The objective of this study was to evaluate the efficacy of fluazuron employed by gavage for the control of the tick Amblyomma sculptum and to determine the bioavailability of fluazuron in the plasma of guinea pigs; then develop, evaluate the palatability, determine the plasma bioavailability of fluazuron, and evaluate the efficacy in the control of A. sculptum after offering medication blocks containing fluazuron to guinea pigs. The study occurred in six stages (Study I to Study IV), in a chronological manner. In Study I, 24 guinea pigs were divided into four groups (n=6): control group (CG; untreated) and treated groups receiving FLU administered by gavage at three doses: G1-1 mg/kg, G2-5 mg/kg and G3-10 mg/kg, once daily for 15 days (d0 to d+14). Serial blood samples were collected from animals in the treated groups. Guinea pigs were artificially infested on days +7 with A. sculptum larvae, and specimens were recovered on days +11 to d+14. In Study II (evaluation of pharmacokinetic parameters), a group of eight animals received fluazuron administered by gavage at a single dose of 10 mg/kg and serial blood samples were collected. In study III a palatable, moisture and temperature resistant bait formulation containing fluazuron was developed. In study IV the acceptance and palatability of the bait was evaluated. One bait per day for seven consecutive days was offered to the 25 animals in the control group (bait without fluazuron) and the 25 animals in the treated group (bait with fluazuron). In Study V, a single dose of the drug bait (10mg/kg fluazuron) was administered on day 0, one per animal, to 12 guinea pigs. For determination of the pharmacokinetic profile, serial blood samples were collected. In study VI, 32 guinea pigs, divided into four equal groups: control group (CG; untreated) and four treated groups that received a single dose of 10mg/kg on days -21 (G1), -14 (G2) and -7 (G3). All animals in this stage were infested with A. sculptum larvae on day 0 and engorged specimens were recovered on days +4 to +7. The engorged larvae recovered in Studies I and VI were incubated in BOD for 14 days and then a count of specimens that changed to nymphs and live and dead was performed. In Study I, II and IV fluazuron was analyzed in plasma samples by high performance liquid chromatography with ultraviolet detection. In Studies II and V plasma concentrations of fluazuron increased rapidly, indicating rapid absorption and slow elimination. The results allowed the development of a palatable bait containing fluazuron with the ability to interfere with tick moulting. The obtained efficacy of the baits was 64.99% for G1, 61.88% for G2 and 59.31% for G3. Promising perspectives for the development of a palatable bait containing FLU that can be offered every 21 days to capybarae for the control of A. sculptum, at doses higher than 10mg/Kg, can be extracted from the results.

COMMITTEE MEMBERS:
Presidente - 1173660 - FABIO BARBOUR SCOTT
Interna - 2929889 - THAIS RIBEIRO CORREIA AZEVEDO
Externo à Instituição - BRUNO GOMES DE CASTRO - UFMT
Externo à Instituição - GEORGE REGO ALBUQUERQUE - UESC-BA
Externo à Instituição - JOSE RECK JUNIOR - OUTRO
Externa à Instituição - NORMA VOLLMER LABARTHE - FIOCRUZ