Banca de QUALIFICAÇÃO: GIULIANN FELIPE ALMEIDA SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : GIULIANN FELIPE ALMEIDA SANTOS
DATA : 12/04/2021
HORA: 14:00
LOCAL: Centro de Ciências Agrárias e da Biodiversidade (CCAB) - Google Meet
TÍTULO:

EVALUATION OF THE ANTIBACTERIAL ACTIVITY OF LECTINES FROM Canavalia ensiformis (ConA) (L.) DC. AND Canavalia brasiliensis (ConBr) Mart. ex Benth. AGAINST Staphylococcus aureus STRAINS CARRYING THE QacA/B AND QacC EFFLUX PUMPS

PALAVRAS-CHAVES:

Efflux pump.  Bacterial resistance. Staphylococcus aureus

PÁGINAS: 72
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

Broadly distributed throughout nature, lectins are defined as proteins of non-imune orgin, capable of binding in a specific and reversible way to simple or complex carbohydrates, without altering their structure, having great biological importance. Such proteins of plant origin represent the greatest source of knowledge of this molecule in the scientific community. At the moment threre is a war between scientists and resistente microorganisms, in search of new therapeutic strategies, provided by molecules that can act in isolation or synergistically with existing antibiotics, because the mechanisms used by these microorganisms are increasingly complex. Faced with this problem, this work aims to identify the antibacterial activity of lectins extracted and purified from Canavalia ensiformis(ConA) and Canavalia brasiliensis(ConBr) in the presence of staphylococcus aureus carrying of efflux pump. For this purpose, the purified and lyophilized lectins were obtained by affinity chromatography method on a sephadex G50 column, having a stationary phase consisting of glucose. The inhibitory concentration (MIC) was determined using strains of staphylococcus aureus. The MIC was performed using the serial microdilution method(1:1) in sterile 96-well microplates. Activity tests against strains carryng efflux pumps were performed on two specific strains QacC and QacA/B respectively. The agglutination assay by lectin ConA in strains s.aureus was performed with the protein in its native and desnatured state. The presente study revealed that both ConA e ConBr lectins had na MIC for all strains tested above ore qual to 1024 µg/mL, that is , they were not clinically significant in this assay. Tests involving the eflflux pump mechanism showed that  ConA lectin presented activity for bomb carrying strains of the QacC Family in the presence of oxacilin. The functioning of the mechanism was valided by the concentrations of ethidium bromite, clopromazine and CCCP. The same was not evidenced with ConBr lectin. An agglutinating activity of ConA lectin in its native state was also observed .With the data obtained by the work, it is concluded that ConA was able to present a synergistic activity with oxacilin in strains carrying and efflux pump from the QacC family, possibly aided by the demonstrated agglutination mechanism. Because it is a gram positive bacteria, the richness of carbohydrates on its surfasse may have played a fundamental role in the activity of this lectin.

MEMBROS DA BANCA:
Interno - 1881416 - JUAN CARLOS ALVAREZ PIZARRO
Interno - 1123441 - KAMILA CAMARA CORREIA
Externo à Instituição - ROGÉRIO DE AQUINO SARAIVA - UFSM