Bioprospecção de extratos aquosos e orgânicos de organismos marinhos com potencial antibacteriano

Abstract

Marine organisms have gone through several events of natural selection over the years and have developed control to perpetuate their species, both due to the environment and climatic conditions, as well as their predators who also found ways to overcome adversity. Currently, studies with marine organisms have been growing and showing the potential of purified bioactive compounds, which can be capable of making the treatment of diseases caused by bacteria more effective against strains resistant to the antibiotics already used. Therefore, the study aimed to evaluate the antibacterial potential of aqueous and organic extracts of marine organisms against standard strains of Escherichia coli, Staphylococcus aureus and Staphylococcus epidermidis. Several marine organisms were collected at different points along the coast of Ceará, including Pacheco and Paracuru beaches and the Pedra da Risca do Meio marine state park. After collection, aqueous extracts were prepared with distilled water, while organic extracts were prepared with 50% acetonitrile. The aqueous and organic extracts were confirmed by the antibiogram test, in addition the aqueous extracts were also confirmed by the MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) tests. Of the 50 marine organisms collected, extracts of 12 organisms interacted with an antibacterial effect in aqueous extraction, while extracts of 17 organisms proved to be effective in organic extraction, against at least one of the tested species. Under aqueous conditions, there was a predominance of marine sponges, while in organic extracts, the efficiency was distributed among mollusks, sponges and macroalgae. We can mention the marine sponges Pseudosuberites sp, Mycale sp, Aplysina fistularis and Aplysina lactuca for the aqueous extracts. For organic extracts, the marine sponges Aplysina cauliformis and Agelas sventres, the echinoderm Echinometra lucunter and the mollusc Pugilina morio stood out. Marine sponges Amphimedon compressa and Topsentia ophiraphidites showed inhibitory activity in both extracts. From the collected samples, seven aqueous extracts of marine sponges were capable of achieving bactericidal effects at concentrations below 0.5 mg.mL-1, with emphasis on Pseudosuberites sp., Amphimedon compressa and Mycale sp. Thus, the present study shows promising results for future studies, which could be carried out in order to isolate the potential compounds present in these organisms.