Resumo

The purchase for new antimicrobial agents, based on substances in nature, such as viper venoms, is important due to the increase of bacterial resistance to commonly used antibiotics. The aim was to analyze the inhibitory activity of Bothrops pauloensis venom on growth of Staphylococcus aureus (ATCC 25923) and Enterococcus faecalis (ATCC 19433) and Salmonella enteritidis (ATCC 13076) and Escherichia coli (ATCC 25922) to determine which protein is responsible for major bactericidal activity. The brutal venom bactericidal activity was held in concentrations of 0.5 mg/ml, 1.0 mg/ml and 2.0 mg/ml, by the difused-disc method in Ágar Mueller-Hinton. Afterwards, was performed an ion-exchange CM-Sepharose chromatography and the obtained peaks were analyzed by the same technique with concentration of 1.0 mg/ml, such as other peaks. The fractions with the best activity were chromatographed in a gel filtration Sephadex G-100 column and evaluated. These peaks were chemically characterized by a gel SDS electrophoresis with glycerol, and ezymatically characterized by a phospholipase activity test. With 0,5 mg/ml, B. pauloensis venom was able to inhibit S. aureus growth; however did not inhibited E. coli and S. enteritidis proliferation. With 1.0 mg/ml and 2.0 mg/ml showed bactericidal activity over S. aureus and S. enteritidis, but not upon E. coli. None of concentrations of B. pauloensis venom were enough to inhibit E. faecalis growth. B. pauloensis CM-Sepharose chromatography profile showed 8 fractions, which CM1 presented a greater inhibition of S. aureus and S. enteritidis growth. E. coli and E. faecalis were not inhibited. Thereby, this peak was applied in a Capto-Q column and the 11 obtained peaks were evaluated, and Q8 was capable of inhibiting S. enteritidis and S. aureus growth. Thus, was performed a filtration chromatography and obtained two peaks, of which S2 presented the positive results previously showed. To infer which protein is responsible for the bactericidal activity, was performed a potentiometric phospholipase activity with the positive results, suggesting it to be an acid phospholipase. B. pauloensis brutal venom showed significant effects on bactericidal activity against Gram-positive and Gram-negative bacteria, especially upon S. aureus and S. enteritidis. These results may be useful to further purification and characterization of this protein.