In the recent past, the importance of freshwater algae has grown enormously due to their antibiotic activity against certain species of bacteria known for several disease states like endocarditis, external otitis, skin rash, etc. Also, there is a growing concern among the immunocompromised individuals that they may be susceptible to antibiotics and anti-fungal resistant infections resulting in increased fatality rates. Hence, in this investigation, extraction of potentially bioactive compounds from a natural resources like freshwater algae was performed along with the evaluation of the antimicrobial activities of these extracts against some opportunistic bacteria like Staphylococcus aureus, Escherichia coli, Staphylococcus xylosus and Pseudomonas aeruginosa using well diffusion method. The data showed a statistically significant (P < 0.05) antibacterial activity of the organic extracts (0.1g/ml) obtained from freshwater algae against multi-drug resistant S. aureus and S. xylosus strains as compared to the control. Our data reinforce the importance of bioactive compounds from fresh algae as potential antimicrobial agents, and they could act as an alternative to conventional antibiotics.

Keywords: Freshwater algae, organic extracts, antimicrobial activity, Opportunistic bacteria