Antibiofilm Activity of Acidic Phospholipase Isoform Isolated from <em>Bothrops erythromelas</em> 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, such as phospholipases (PLA2) isolated from snake venom, which have important biological 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 PLA2 from B. erythromelas, searching for heterologous activities against bacterial biofilm. Methods: Venom extraction and quantification were followed by RP-HPLC in C18 column, MALDI-ToF mass spectrometry and sequencing by Edman degradation. All experiments were monitored by specific activity using 4-nitro-3 (octanoyloxy) benzoic acid (4N3OBA) substrate. In addition, hemolytic tests and anti-bacterial 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: PLA2, after one purification step, presented 31 N-terminal amino acid residues, and molecular weight of 13656.4 Da with enzymatic activity confirmed in 0.06 µM concentration. Antibacterial activity against S. aureus (IC50 = 30.2 µM) and antibiofilm activity against A. baumannii (IC50 = 1.1 µM) were observed. Conclusions: This is the first time that PLA2 purified from B. erythromelas venom has appeared as an alternative candidate in studies of new antibacterial medicines.