Banca de QUALIFICAÇÃO: ANDERSON PAULO RODRIGUES LOPES
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.DISCENTE : ANDERSON PAULO RODRIGUES LOPES
DATA : 25/02/2022
HORA: 14:00
LOCAL: Google Meet (https://meet.google.com/ciy-affq-yzu)
TÍTULO:
ANTIMICROBIAL ACTIVITY OF THE ESSENTIAL OIL FROM Lippia gracilis ASSOCIATED WITH A NATURAL OINTMENT AGAINST Staphylococcus aureus STRAINS.
PALAVRAS-CHAVES:
Biofilm; essential oil; Lippia gracilis; natural ointment.
PÁGINAS: 40
GRANDE ÁREA: Outra
ÁREA: Ciências Ambientais
RESUMO:
Antimicrobial resistance (AMR) has emerged as one of the main health problems due to the high rates of infections caused by bacteria, parasites, viruses or fungi. Infections are the main consequences of chronic wounds, due to the rapid proliferation of microorganisms. These microorganisms have a very efficient defense mechanism capable of forming biofilms, and this results in a delay in the healing process. In this sense, the discovery of new actives that have antimicrobial activity is extremely relevant to overcome the current problems of antibiotic resistance. In this sense, the objective of this study was to evaluate the antimicrobial and antibiofilm activity of Lippia gracilis oil, associated with a natural ointment and also with the antibiotic ampicillin, against strains of Staphylococcus aureus ATCC 25923, Staphylococcus aureus 700698 and Staphylococcus aureus JKD6008. To determine the antimicrobial activity, L. gracilis and the ointment were diluted in concentrations ranging from 10 to 0.156 mg/mL and distributed in 96-well polystyrene flat-bottom plates, with each bacterial suspension adjusted (1x106 CFU/mL) in TSB medium, then incubated for 24 hours at 37°C. The effect of L. gracilis oil, ointment and both associations were evaluated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The MIC values were combined with the antibiotic ampicillin and its effects were evaluated using the checkerboard technique, while the MBC values were used to infer the death time of bacteria treated with L. gracilis and ointment. Antibiofilm activity was evaluated by quantification of biofilm biomass by crystal violet (CV) staining and by the number of viable biofilm cells by colony forming units (CFU) count. The essential oil showed MIC at 2.5 mg/mL in the three S. aureus tested and CBM only in S. aureus JKD6008 at the same concentration. The ointment, on the other hand, showed no antimicrobial activity in the three strains tested. The combination of Lippia oil with the ointment resulted in MIC for S. aureus ATCC 25923 at 2.5 mg/mL and 1.25 mg/mL for S. aureus ATCC 700698 and S. aureus JKD6008. Furthermore, they showed CBM at 5 mg/mL in S. aureus ATCC 25923 and ATCC 700698. The synergistic effect against S. aureus ATCC 25923 (ICIF=0.375), S. aureus ATCC 700698 (ICIF=0.375) strains. Regarding antibiofilm activity, L. gracilis oil, ointment and its association are able to reduce significantly the biofilm formation and preformed biofilm. In conclusion, the essential oil from L. gracilis showed antimicrobial activity against S. aureus strains and its biofilms tested both alone and in association with a natural ointment and ampicillin.
MEMBROS DA BANCA:
Externa à Instituição - MARCIANA BIZERRA DE MORAIS
Interna - 3396 - CYNTHIA CAVALCANTI DE ALBUQUERQUE
Interno - 023.053.853-31 - MAYRON ALVES DE VASCONCELOS - UFC