Screening of antimicrobial activity of marine sponge extracts collected from Tunisian coast

The antibacterial activity of the ethyl acetate extracts of seven marine sponges collected from Tunisian Mediterranean coast (Monastir) was tested against eight human pathogenic bacteria and six human pathogenic fungi using the agar disk diffusion method. The results showed that 90% of the sponge extracts presented significant activity against at least one bacterial strain and only 20% were active against fungi. Sponge extracts of Agelas oroides and Axinella damicornis appeared to be quite promising due to their capacity to inhibit the growth of Pseudomonas aeruginosa and gentamycin resistant strains Listeria monocytogenes and Enterococcus feacalis as well as a broad-spectrum activity against all the other bacteria. The antifungal activity of these sponge extracts is not so interesting, in fact only three among seven sponge extracts showed moderate activity against fungal strains. Agelas oroides showed an interesting antibacterial activity and had also a moderate activity against fungal strains tested in this study. These promising results in relation with antibacterial and antifungal activity in vitro open the way for complementary investigation in order to purify and identify active molecules. © 2007 Elsevier Masson SAS. All rights reserved.