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 the Tunisian Mediterranean coast (Monastir) were tested against eight human pathogenic bacteria and six human pathogenic fungi using the agar disk diffusion method. The results show that 90% of the sponge extracts present significant activity against at least one bacterial strain. Extracts of the sponges 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 of Listeria monocytogenese and Enterococcus feacalis as well as broad spectrum activity against all the other bacteria. The antifungal activity of these sponge extracts is not so promising, in fact only three among 9 sponge extracts show moderate capacity of growth inhibition against fungi strains. Agelas oroides which shows interesting antibacterial activity, has moderate activity against fungi strains tested in this study. Our results with antibacterial and antifungal activity in vitro open the way for complementary investigation in order to purify and identify active molecules.