Banca de DEFESA: MARIA TAMIRES ALVES ESPINDOLA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARIA TAMIRES ALVES ESPINDOLA
DATE: 27/02/2025
TIME: 08:30
LOCAL: Híbrida - Auditório da Biblioteca/UFAPE e Plataforma Google Meet
TITLE:

Evaluation of the antimicrobial potential of the plants Byrsonima sericea DC., Psidium guajava, and Myroxylon peruiferum L.

KEY WORDS:

Plant extracts; antimicrobial activity; synergism.

PAGES: 80
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

Nosocomial infections are among the greatest health challenges, as microbial resistance reduces therapeutic options for often debilitated patients. Due to the variety of chemical compounds, plants are targets for research into antimicrobial activity. Therefore, this study aimed to evaluate the antimicrobial potential of extracts and fractions from Byrsonima sericea DC, Psidium guajava, and Myroxylon peruiferum L. Ethanol extracts were prepared from leaves (EEB.F.) and branches (EEB.G.), and subsequently fractionated into hexane-soluble (F.HEX.F. and F.HEX.G.), chloroform-soluble (F.CL.F and F.CL.G.), ethyl acetate-soluble (F.ACOET.F. and F.ACOET.G.), and water-soluble fractions (F.AQ.F. and F.AQ.G.). The extracts and fractions were tested for antimicrobial activity against S. aureus ATCC 25923, E. faecalis ATCC 29212, E. coli ATCC 25922, K. pneumoniae UFPEDA 396, and P. aeruginosa UFPEDA 416 using the microdilution method. Fractions and extracts showing MIC were further tested with antibiotics to assess synergistic effects. Phytochemical assays were conducted on extracts and fractions, and toxicity analysis was performed using Artemia salina. So far, results have been discussed only for M. peruiferum L., where branch extracts and fractions showed promising results, particularly F.HEX.G. against S. aureus (MIC and MBC of 0.25 mg.mL^-1) and E. faecalis (MIC and MBC of 0.5 mg.mL^-1). F.HEX.G. at ½ MBC (0.125 mg.mL^-1) in microbial death kinetics tests did not exhibit bactericidal effects at any time intervals but reduced microbial growth. EEB.G., F.HEX.G., and F.ACOET.G. in combination with gentamicin completely inhibited E. coli and K. pneumoniae at the lowest tested concentration of 0.063 mg.mL^-1. When combined with vancomycin, F.ACOET.G. was notably effective with MIC values of 0.25 mg.mL^-1 against S. aureus and 0.125 mg.mL^-1 against E. faecalis. Phytochemical analysis revealed the presence of phenols, flavones, flavonols, xanthones, triterpenoids, alkaloids, anthraquinones, and coumarins. No toxicity was observed in the plant samples with Artemia salina nauplii. The escalating problem of microbial resistance underscores the importance of these findings. The extracts and fractions from M. peruiferum in this study exhibited antimicrobial activity, warranting further investigation.

COMMITTEE MEMBERS:
Presidente - KEILA APARECIDA MOREIRA
Externa à Instituição - ANA CAROLINA DE CARVALHO CORREIA
Externa à Instituição - ELISÂNGELA RAMOS CASTANHA
Externo à Instituição - JOSÉ ERICK GALINDO GOMES
Externa à Instituição - PATRICIA LINS AZEVEDO DO NASCIMENTO