Banca de QUALIFICAÇÃO: PAMELLA PRYSCILA DE ALVARENGA BISSOLI MACIEL DE LIMA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : PAMELLA PRYSCILA DE ALVARENGA BISSOLI MACIEL DE LIMA
DATE: 17/09/2025
TIME: 13:00
LOCAL: Plataforma Google Meet
TITLE:

DOSE AND AGE-DEPENDENT EFFECTS OF EIMERIA SPP. INFECTION ON CYTOKINE AND INTESTINAL INTEGRITY GENE EXPRESSION IN BROILER CHICKENS

KEY WORDS:

Eimeria tenella, Eimeria acervulina, Eimeria maxima, Coccidiosis, Cytokine expression, Gut health, Broilers

PAGES: 44
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

The aim of this study was to evaluate the effects of Eimeria spp. challenge dose and age on gene expression of pro-and anti-inflammatory cytokines and intestinal integrity markers in broiler chickens. One-day-old chicks were orally challenged with a commercial vaccine at doses of 10 × (G1) and 40 × (G2) higher than those recommended by the manufacturer, whereas the control group (GC) received PBS. Broiler chickens were euthanized at 7, 14, and 21 days post-infection (dpi) for cecal tissue collection. The results revealed early intestinal barrier disruption at 7 dpi, particularly in G2, when tight junction genes (ZO-A, claudin-C, and JAM) were significantly downregulated. By 14 dpi, occludin gene expression had increased in G2, suggesting a compensatory attempt to restore gut integrity. The immune response followed a distinct pattern depending on dose and age. At 14 dpi, the pro-inflammatory cytokines IL1β, IL2, and IFN-γ peaked in both groups, although the response was stronger in G1, indicating more controlled activation. However, by 21 dpi, G2 showed marked suppression of IL10 and IFN-γ. In contrast, CD8 expression was strongly upregulated in G2 at 21 dpi, indicating a delayed but heightened cytotoxic response. Interestingly, despite shifts in cytokine expression, intestinal integrity markers showed only limited changes over time, suggesting that the immune response was more affected by parasite load than by structural damage to the gut. These findings highlight how dose and age shape the host response to Eimeria spp., and emphasize the importance of tailored coccidiosis management strategies in poultry production.

COMMITTEE MEMBERS:
Presidente - 3701492 - HUARRISSON AZEVEDO SANTOS
Externo ao Programa - 3470547 - JEAN KAIQUE VALENTIM - UFRRJExterno ao Programa - 1121773 - TULIO LEITE REIS - UFRRJExterno à Instituição - THOMAS SALLES DIAS - UFF
Externa à Instituição - DAYSE LIMA DA COSTA ABREU - UFF