Antibiotic activity of marine algae against multi-antibiotic resistant bacteria.

The antibiotic activity of six species of marine algae (Rhodophyta, Phaeophyta and Chlorophyta) against multi-antibiotic resistant (MAR) bacteria was investigated. The study shows that various degrees of activity were present in 18 out of the 24 algal extracts. The highest activity was for Rhodophyta (diameter of the inhibited zone ranged from 10-22 mm), whilst the lowest was for Chlorophyta (8-12 mm). The taxonomic trends were seen between extracts, as the best solvents were found to be ether, methanol and acetone for Rhodophyta, Phaeophyta and Chlorophyta, respectively. The importance of these results on public health are discussed.