Banca de DEFESA: NATANAEL SALES SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : NATANAEL SALES SILVA
DATE: 23/10/2023
TIME: 14:30
LOCAL: vIDEOCONFERêNCIA
TITLE:

ANTIMICROBIAL PEPTIDES PENTADACTYLIN AND FALLAXIN: EVALUATION OF SYNERGIC EFFECTS WITH POLYMYXIN B ON Klebsiella pneumoniae CARBAPENEMASE AND IMMUNOMODULATORY EFFECTS ON HUMAN NEUTROPHILS.

KEY WORDS:

L. labyrinthicus, Pentadactylin, Fallaxin, Neutrophils, Synergism, KPC.

 

ANTIMICROBIAL PEPTIDES PENTADACTYLIN AND FALLAXIN: EVALUATION OF SYNERGIC EFFECTS WITH POLYMYXIN B ON Klebsiella pneumoniae CARBAPENEMASE AND IMMUNOMODULATORY EFFECTS ON HUMAN NEUTROPHILS.

PAGES: 79
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

 

Antimicrobial peptides are molecules produced naturally by a variety of organisms, including amphibians such as toads and frogs that secrete them into their skin as a form of defense against pathogens. These peptides act against a wide range of bacteria, fungi and viruses and have significant therapeutic potential due to their ability to kill microorganisms without causing harm to human cells. The application of these peptides is promising in several areas, such as the development of new antibiotics and the treatment of infections. Furthermore, they are being studied as an alternative to traditional antibiotics that are increasingly ineffective due to the selection of microbial resistance genes. However, despite the promising potential of these peptides, there is still much research to be done to better understand their effectiveness in different contexts and the feasibility of their large-scale application. In addition to antimicrobial activity, peptides present in anuran skin secretions can also exhibit immunomodulatory activity, which means they can affect the function of the immune system. These peptides can act as proinflammatory or antiinflammatory agents, regulating the body's immune response. The present project aimed to evaluate the antibacterial and synergistic effect of the antimicrobial peptides pentadactylin and fallaxin on multidrug-resistant bacteria Klebsiella pneumoniae carbapenemase (KPC). Additionally, the response of human neutrophils exposed to these molecules was evaluated. Purification by RP-HPLC and mass spectrometry analysis revealed a high degree of homogeneity of these peptides for carrying out the proposed assays. Both peptides showed antibacterial activity against KPC bacteria (Minimum Inhibitory Concentration, MIC = 128 μM for both peptides), and the damage caused was evaluated by scanning electron microscopy (SEM), which showed deformations in the membrane of this bacterium, which which possibly leads to the destruction of the wall and lysis of the microorganism. Drug combination tests between the peptides and the antibiotic polymyxin B indicated that both have synergistic effects, reducing the MIC when tested against KPC bacteria. When evaluating their immunomodulatory effects, both peptides did not show significant results when modulating the phagocytic response of neutrophils. Fallaxin promoted a decrease in the production of Reactive Oxygen Species (ROS). Both peptides did not exhibit chemotactic potential. The synergistic and immunomodulatory effects of the peptides pentadactylin and fallaxin on neutrophils demonstrate other possibilities of therapeutic application for these peptides.

COMMITTEE MEMBERS:
Externo ao Programa - ***.367.691-** - LUCAS SILVA DE OLIVEIRA - UnB
Externo à Instituição - MARCELO HENRIQUE SOLLER RAMADA - UCB
Presidente - 1189826 - MARIANA DE SOUZA CASTRO
Interno - 1354514 - OSMINDO RODRIGUES PIRES JUNIOR