Banca de DEFESA: LIVIA FERNANDA RAMOS MATEUS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LIVIA FERNANDA RAMOS MATEUS
DATE: 19/02/2026
TIME: 16:00
LOCAL: Sala de Aulas do PPGSA (1A, bloco A, UFAPE)
TITLE:

Antimicrobial activity of pitangueira (Eugenia uniflora L.) extract against mastitis-causing bacteria

KEY WORDS:

Staphylococcus aureus; silver nanoparticles; green synthesis; nanotechnology.

PAGES: 70
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Saúde Animal (Programas Sanitários)
SUMMARY:

Bovine mastitis is one of the main diseases affecting dairy cattle, with significant economic impact and relevance to public health. Staphylococcus aureus is one of its principal etiological agents, particularly due to its ability to develop antimicrobial resistance. In this context, the use of medicinal plants as sources of bioactive compounds, especially Eugenia uniflora, as well as the application of nanotechnology, notably silver nanoparticles, emerge as alternative and com plementary strategies to conventional antibiotic therapy. This study aimed to evaluate the phytochemical profile, toxicity, and antimicrobial activity of the crude extract and ethyl acetate fraction from the stem of E. uniflora, in addition to investigating the antimicrobial activity of silver nanoparticles synthesized via a green route using the plant extract and by a conventional chemical method. The plant material was subjected to extraction and liquid–liquid fractiona tion, with determination of crude extract yield. Toxicity was assessed using the Artemia salina bioassay. Qualitative phytochemical screening was performed to identify the main classes of secondary metabolites, along with the quantification of total phenolic compounds and total fla vonoids. Silver nanoparticle synthesis was monitored by UV–Vis spectroscopy to evaluate for mation and colloidal stability. Antimicrobial activity was determined by minimum inhibitory concentration and minimum bactericidal concentration assays against S. aureus strains associ ated with bovine mastitis. The results demonstrated the presence of several classes of bioactive metabolites in the stem of E. uniflora, with relevant levels of phenolic compounds and fla vonoids. The extracts showed antimicrobial activity with a predominantly bacteriostatic effect. In contrast, silver nanoparticles exhibited significantly higher activity, displaying bactericidal effects at sub-microgram per milliliter concentrations, including against resistant strains. It is concluded that the proposed objectives were achieved, the research problem was elucidated, and the stem of E. uniflora represents a promising and still underexplored source of bioactive compounds, while the green synthesis of silver nanoparticles emerges as a relevant alternative for the control of pathogens associated with bovine mastitis.

COMMITTEE MEMBERS:
Presidente - 1885755 - PEDRO GREGORIO VIEIRA AQUINO
Externa ao Programa - 1287974 - ÂNGELA IMPERIANO DA CONCEIÇÃO - UFAPEExterna à Instituição - MARIA TAMIRES ALVES ESPÍNDOLA