Banca de QUALIFICAÇÃO: AMANDA VIEIRA DE BARROS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : AMANDA VIEIRA DE BARROS
DATE: 28/07/2021
TIME: 17:00
LOCAL: APRESENTAÇÃO POR VÍDEO CONFER~ENCIA
TITLE:

EVALUATION OF IN VITRO ANTIBACTERIAL AND ANTIBIOFILM ACTIVITY OF ESSENTIAL OILS FROM CONDIMENTAL PLANTS ON POTENTIALLY PATHOGENIC BACTERIA

KEY WORDS:

bioactive compounds; natural antibacterials; Bacterial adherence; Z. officinale.

PAGES: 80
BIG AREA: Ciências Biológicas
AREA: Microbiologia
SUBÁREA: Microbiologia Aplicada
SPECIALTY: Microbiologia Médica
SUMMARY:

In view of the search for new possibilities for bacterial control, researches using condiment plants in alternative methodologies are gaining more and more prominence, due to their nutritional value and antibacterial potential. Thus, antimicrobials of natural origin could be an effective and economically viable alternative for the conservation of food, or even in the treatment of infections caused by pathogenic bacteria, replacing the use of synthetic substances. Based on these statements, the main objective of this study was to evaluate the antibacterial and antibiofilm potential of essential oils from spicy plants against the food and clinical strains Escherichia coli (25922), Staphylococcus aureus (25923), Klebsiella pneumoniae (10031), Salmonella typhimurium and Pseudomonas aeruginosa. The plants Rosmarinus officinalis, Zingiber officinale and Allium sativum were obtained commercially, and the oils extracted by hydrodistillation coupled with Clevenger. Subsequently, their chemical profiles were evaluated by the Gas Chromatography technique coupled to a Mass Spectrometer. For the evaluation of the antimicrobial activity the broth microdilution method was used for the determination of the Minimum Inhibitory Concentration, and later determination of the Minimum Bactericidal Concentration. The subinhibitory concentrations of MIC, 2xMIC and 4xMIC observed for each oil against the tested bacteria were used to analyze the effect of the oils in reducing biofilm formation, evaluated by crystal violet uptake tests and optical density reading at 595 nm. In the evaluation of the chemical profile of the essential oils, a higher concentration of monoterpenes and sesquiterpenes was observed in R. officinalis, Z. officinale, while the oil from A. sativum was composed mostly of organosulfur substances. For the evaluation of antibacterial activity, the essential oils showed activity against the tested strains, especially against P. aeruginosa (MIC 0.83-1 µg/mL and MBC 1.33-5.33 µg/mL). The best results of the oil of R. officinalis were observed against the strain of S. aureus (MIC 8 µg/mL and MBC 3.33 µg/mL), while Z. officinale achieved better inhibitory and bactericidal effect against E. coli (MIC 4 µg/mL and MBC 5.33 µg/mL). The oil of A. sativum showed better activity against K. pneumoniae (MIC 4 µg/mL and MBC 5.33 µg/mL). Evaluating the effect of oils on biofilm inhibition, R. officinalis was able to reduce only E. coli formation (60%), showing no effect against the other biofilms tested. With the exception of P. aeruginosa, Z. officinale was able to reduce biofilm formation by 100%. A higher resistance of P. aeruginosa biofilm was also observed in the treatment with A. sativum. However, the oil was able to reduce S. aureus biofilm formation by 100%. It is concluded that, concentration of monoterpenes, the essential oil of Z. officinale showed better antimicrobial activity and reducing the formation of biofilms, configuring itself as a promising alternative for the conservation of food and combat pathogenic microorganisms.

BANKING MEMBERS:
Presidente - 1714290 - RENATO MOTTA NETO
Interna - 1720860 - VANESSA DE PAULA SOARES RACHETTI
Externo à Instituição - CAIO AUGUSTO MARTINS AIRES - UFERSA