Potencial antibacteriano e antibiofilme de L-aminoácido oxidases isoladas de peçonhas botrópicas contra bactérias multirresistentes.

Abstract

Bacterial infections associated with biofilm formation present high mortality. In the present work, was demonstrated the ability of two LAAOs obtained from Bothrops moojeni and Bothrops jararacussu venoms to inhibit biofilm formation of multiresistant lineages of S. aureus ATCC BAA44, E. coli ATCC BAA198, and clinical isolates. The purified biomolecules presented molecular weight of ~ 64.31 kDa and ~ 60.73 kDa and a high homogeneity, corresponding to BmooLAAO-I and BjussuLAAO-II; furthermore, possess enzymatic activity upon L-Leucine of 4,136.683 e 5,205.740 U/mg/min, respectively, and shares 89% of identity in the primary structure and RMSD values of 0.105 and 0.078 between all atoms and Cα, respectively. BmooLAAO-I possesses a higher number of glycosylated motifs and positively charge density close to the glycosylation sites than BjussuLAAO-II, which can be correlated with the interaction with the bacterial surface and the biofilm extracellular matrix. Upon the multiresistant strains S. aureus ATCC BAA44 and S. aureus (clinical isolates), BmooLAAO-I (MIC = 0.12 and 0.24 µg/mL, respectively) and BjussuLAAO-II (MIC = 0.15 µg/mL) control intensively the bacterial growth, while against multiresistant E. coli ATCC BAA198 and E. coli (clinical isolates), BmooLAAO-I (MIC = 15.6 and 62.5 µg/mL, respectively) and BjussuLAAO-II (MIC = 4.88 and 9.76 µg/mL, respectively) showed a lower extent effect. Regarding the antibiofilm action, BmooLAAO-I (MICB50 = 0.195 µg/mL) and BjussuLAAO II (MICB50 = 0.39 µg/mL) inhibited the biofilm formation of S. aureus (clinical isolated) in 88% and 89%, respectively. In parallel, BmooLAAO-I and BjussuLAAO-II at concentrations of 1.56 µg/mL inhibited the biofilm formation by 89% and 53% of E. coli (clinical isolated). In the scanning electron microscopy analyses, the MICs of BmooLAAO-I and BjussuLAAO-II affected the bacteria morphology, inducing constrictions, undulations and elongations, and the dismantling of biofilm architecture. The present study points to the development of new strategies for the treatment of bacterial infections.