Banca de DEFESA: RAFAEL BARBOSA DE MOURA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : RAFAEL BARBOSA DE MOURA
DATA : 30/01/2020
HORA: 14:30
LOCAL: Centro de Ciências Agrárias e da Biodiversidade (CCAB)
TÍTULO:

Evaluation of Antibacterial and Modulatory Activity of Lectins from Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr) on standard and multiresistant strains

PALAVRAS-CHAVES:

Lectins. Efflux pump. Bacterial resistance. Antimicrobials.

PÁGINAS: 48
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

Lectins are proteins capable of binding reversibly and specifically carbohydrates, which have the ability to agglutinate red blood cells and are found in various organisms such as plants, organisms eukaryotes and prokaryotes. Plant lectins are a group of proteins of great biological potential and represent the class of lectins which present more studies in the literature. Nowadays there is a need for researchers to discover new drugs that can act directly or indirectly on bacteria, as clinically antimicrobial resistance mechanisms are increasing on an unprecedented scale. The need to find molecules that can help reverse these resistance mechanisms is of utmost need today. In this context, this work aims to isolate the lectins present in seeds of Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr), as well as to verify their antimicrobial potential against standard, multidrug resistant bacteria and efflux pump carriers. For this purpose the seeds were ground and the extract made in 0.15M Nacl, for subsequent extraction in Sephadex-G50 column, where the solid phase is made of glucose, the proteins were eluted using 0.1M glycine, pH 2.6 and samples read on spectrophotometer at 280 nm. Subsequently the samples were dialyzed and lyophilized for microbiological tests. The Minimum Inhibitory Concentration (MIC) was determined using Staphylococcusaureus and Escherichiacoli strains, the strains were kept in specific medium to prove their subtype. MIC was performed in sterile 96-well microplates and serially diluted 1:1. Modulatory activity was evaluated using the antibiotics gentamicin, ciprofloxacin and ampicillin. For the efflux pump test were used two strains of S. aureus containing NorA and MepA respectively. The study showed that ConA and ConBr lectins have a MIC for all bacteria tested above or equal to 1024µg / mL, showing no clinically significant findings for this test; however, in modulation activities ConA was able to modulate the activity of gentamicin in strains of wild S. aureus (1199) and ConBr showed significant modulatory activity for modulation in S. aureus (1199) in the presence of ciprofloxacin. Concavalin A (ConA) shows significant activity for NorA efflux pump bacteria in the presence of norfloxacin. Similar activities were not clinically significant for ConBr. Thus, it can be concluded that ConA was able to modulate gentamicin activity in gram-positive strains, suggesting that the structure of this bacterium, due to the large amount of carbohydrates on its surface, may provide a mechanism of action that can be aided. In the presence of lectins, the same can be observed in the results with efflux pumps (NorA) in which lectin was able to assist the antimicrobial drug by the presence of this resistance mechanism.

 

 

 

 

MEMBROS DA BANCA:
Presidente - 2185176 - FRANCISCO NASCIMENTO PEREIRA JUNIOR
Externo à Instituição - HENRIQUE DOUGLAS MELO COUTINHO - URCA
Interno - 1123441 - KAMILA CAMARA CORREIA
Interno - 1305746 - THIAGO MIELLE BRITO FERREIRA OLIVEIRA