Antibiofilm Activity of Acidic Phospholipase Isoform Isolated from Bothrops erythromelas Snake Venom

Introduction: Bacterial resistance is a worldwide public health problem, requiring new therapeutic options. An alternative approach to this problem is the use of animal toxins isolated from snake venom, such as phospholipases A(2) (PLA(2)), which have important antimicrobial activities. Bothrops erythromelas is one of the snake species in the northeast of Brazil that attracts great medical-scientific interest. Here, we aimed to purify and characterize a PLA(2) from B. erythromelas, searching for heterologous activities against bacterial biofilms. Methods: Venom extraction and quantification were followed by reverse-phase high-performance liquid chromatography (RP-HPLC) in C18 column, matrix-assisted ionization time-of-flight (MALDI-ToF) mass spectrometry, and sequencing by Edman degradation. All experiments were monitored by specific activity using a 4-nitro-3-(octanoyloxy) benzoic acid (4N(3)OBA) substrate. In addition, hemolytic tests and antibacterial tests including action against Escherichia coli, Staphylococcus aureus, and Acinetobacter baumannii were carried out. Moreover, tests of antibiofilm action against A. baumannii were also performed. Results: PLA(2), after one purification step, presented 31 N-terminal amino acid residues and a molecular weight of 13.6564 Da, with enzymatic activity confirmed in 0.06 µM concentration. Antibacterial activity against S. aureus (IC(50) = 30.2 µM) and antibiofilm activity against A. baumannii (IC(50) = 1.1 µM) were observed. Conclusions: This is the first time that PLA(2) purified from B. erythromelas venom has appeared as an alternative candidate in studies of new antibacterial medicines.