Bioprospecting from marine coastal sediments of Colombian Caribbean: screening and study of antimicrobial activity.

AIMS: To isolate micro-organisms associated with marine coastal sediments of Colombian Caribbean Sea and for evaluating its antimicrobial activity in order to identify the most active strains. METHODS AND RESULTS: One hundred and four strains were isolated from sediment samples of the Colombian Caribbean Sea. First at all, an antimicrobial activity screening was made using agar well diffusion method against the pathogens: Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Candida albicans, Candida tropicalis and Pseudomonas aeruginosa. Seventeen strains showed strong antimicrobial activity and were identified as members of the Streptomyces, Micrococcus and Bacillus genera. Organic extracts were produced by liquid-liquid extraction and HPLC profiles of the most active extracts were obtained. Then, the antimicrobial activity of the extracts was evaluated with the broth microdilution test, finding antimicrobial activities superior to 90% against S. aureus MRSA and C. albicans. HPLC profiles indicated the presence of different antimicrobial compounds. CONCLUSION: This study demonstrates that the microorganisms isolated from the Colombian Caribbean Sea are possible sources of antimicrobial compounds against pathogenic strains. SIGNIFICANCE AND IMPACT OF STUDY: These results contribute to the knowledge of the biotechnological potential of the Colombian biodiversity for the development of pharmaceutical products that can counteract the increasing problem of pathogen resistance.