Abstract
Marine sponges are on focus for their ability to produce compounds with antimicrobial activity. In this study, extracts from nine Red Sea sponges obtained from Saudi coasts (Farasan Islands, Al Lith, Al-Qunfudhah and Yanbu) were screened against clinical and marine bacterial isolates. Results showed that the extracts of Callyspongia crassa and Aplysina fulva were potent against the Gram-positive Bacillus subtilis pathogens (inhibition zone: 9-15 and 16-25 respectively; LC50 = 18.2 and 21.7 mu g/mL respectively). Extracts of Callyspongia crassa and Aplysina fulva showed also activity against Staphylococcus aureus (inhibition zone: 5-8 and 16-25 respectively; LC50 = 215.2 and 302.6 mu g/mL respectively). However, extracts of Callyspongia siphonella, Phyllospongia lamellose, Iotrocbota purpurea and Clathria spp. showed no activity against all tested strains including the Gram-negative E. coli. With respect to marine bacterial strains, extracts of Piona vastifica and Callyspongia crassa showed high activity (LC50 = 19-22 mu g/mL) whereas the rest showed low activity (LC50 = 270-350 mu g/mL).
These findings provide evidence that marine sponges from the Red Sea have the potential to be good candidates in the search for new effective drugs against Gram-positive pathogenic bacteria. (C) 2017 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.