Banca de DEFESA: JOSE FRANCISCO GIMENEZ MORAN

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JOSE FRANCISCO GIMENEZ MORAN
DATE: 29/02/2024
TIME: 17:00
LOCAL: Sala virtual Google meet
TITLE:

IMMUNE RESPONSE CHARACTERIZATION IN BUFFALOES INFECTED WITH MYCOBACTERIUM AVIUM PARATUBERCULOSIS IN THE PARÁ STATE, BRAZIL.

KEY WORDS:

Mycobacterium avium subspecies paratuberculosis, IFNγ, ELISA, Paratuberculosis, Immune Response.

PAGES: 30
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Epidemiologia Animal
SUMMARY:

Paratuberculosis, or Johne's disease, is a chronic infectious disease caused by Mycobacterium avium subspecies paratuberculosis (Map), with worldwide distribution, affecting both ruminants and non-ruminants. In humans, it has been associated with Crohn's disease. The disease is characterized by thickening of intestinal villi with progressive loss of intestinal absorption capacity, resulting in chronic diarrhea, weight loss, cachexia, and death. Cattle become infected in the first few months of life, and Map excretion in feces begins around one year of age, with disease symptoms appearing in adult animals. Early in the infection, Map generates a cellular immune response, which decreases as the disease progresses, with a humoral immune response appearing and being maintained in the adult animal until the end of the disease. Diagnosis is mainly based on clinical signs, necropsy findings, and detection of antibodies by ELISA in adult animals, leaving infected young animals unidentified, representing an important source of transmission. Most studies have evaluated the immune response to Map infection in cows, sheep, and goats, but there is currently no information on work done in buffaloes. The main objective of this study was to evaluate the immune response in a herd of buffaloes in the state of Pará, Brazil, between July 2023 and January 2024. A selected group of 40 buffaloes over 2 years of age, out of a total of 800 subjected to ELISA testing, (16 animals with positive serology for Map and 24 animals with negative serology for Map). In addition to ELISA to evaluate humoral immunity, the study group underwent the Comparative Cervical Test (CCT) and Interferon-gamma (IFNγ) test to measure cellular immunity, with fecal sample collection for Map DNA detection by qPCR from the group. The results showed different patterns of immune response: cellular patterns (PPDA+/IFNγ- [14/40]); (PPDA-/IFNγ+ [3/40]); (PPDA+/IFNγ+ [6/40]), mixed patterns (PPDA+/IFNγ-/ELISA+ [3/40]), (PPDA+/IFNγ+/ELISA+ [8/40]), and humoral pattern (PPDA-/IFNγ-/ELISA+ [5/40]). The extracted DNA was quantified and showed an absorbance ratio at 260/280 below 1.8 and an absorbance ratio at 260/230 above 1.0. qPCR was performed, but there was no amplification. Different response patterns were observed, from cellular patterns through mixed patterns to ending with a humoral pattern, which is observed in some cases in animals with advanced disease. The cellular response is not associated with the age or physiological status of the animals. The DNA extracted using a specific commercial kit for fecal DNA extraction has low quality and/or is contaminated, as shown by the values obtained in the absorbance ratios. The non-amplification of DNA may be due to the low quality of the extracted DNA, demonstrating that quality DNA extraction from feces remains a crucial point for success in pathogen identification through qPCR.

BANKING MEMBERS:
Externo ao Programa - 2150577 - ALEXANDRE DO ROSARIO CASSEB
Interno - 1556914 - EDNALDO DA SILVA FILHO
Externa à Instituição - ELIZABETH MACHADO BARBOSA - UNIFAP
Externa à Instituição - HILMA LÚCIA TAVARES DIAS - UFPA
Externa ao Programa - 2116073 - PRISCILA DI PAULA BESSA SANTANA
Externo ao Programa - 2495071 - SEBASTIAO TAVARES ROLIM FILHO