Investigação do potencial antibiofilme da lectina de folhas de Schinus terebinthifolia Raddi contra Staphylococcus aureus

Abstract

Biofilms are complex microbial communities that have been associated with the incidence of infections, including in the hospital environment. Its formation is considered a determining factor for virulence in microorganisms and strongly contributes with the microbial resistance to conventional antimicrobials. In this sense, the search for natural compounds with antimicrobial activity that are more effective and less toxic to host cells. Plants are important sources of bioactive compounds, including lectins, a class of carbohydrate-binding proteins whose antimicrobial action has been reported. SteLL is a leaf lectin isolated from Schinus terebinthifolia Raddi (Anacardiaceae) with antimicrobial action that was previously reported. In this work, the antibacterial and antibiofilm potential of SteLL against sensitive (UFPEDA 02) and oxacillin resistant (UFPEDA 670) isolates of Staphylococcus aureus was evaluated. SteLL was a bacteriostatic and bactericidal agent against UFPEDA 02 and UFPEDA 670 isolates with MIC50 (Minimum Inhibitory Concentration) of 12.5 and 25.0 μg/mL and CMB (Minimum Bactericidal Concentration) of 50.0 and 100 μg/mL, respectively. The growth kinetics of the cells treated with SteLL revealed a dose-dependent growth inhibition regarding to control. SteLL caused morphometric alterations in S. aureus cells and inhibited biofilm formation of UFPEDA 02 at concentrations between 400 and 25.0 μg/mL and UFPEDA 670 between 400 and 100 μg/mL. In conclusion, SteLL is an antibacterial agent against Staphylococcus aureus by inhibiting the growth, promoting cell death and inhibiting bacterial biofilm formation.