Qom University of Medical Sciences Journal

Background and Objectives:Considering the increasing rate of drug-resistant strains among microorganisms, finding antimicrobial and antifungal compounds from natural materials, which certainly havefewer side-effects, has long been of interest to researchers. Hence, this study aimed to evaluate antibacterial and antifungal effects of ethanolic extract of red algae Gracilariaarcuata of ChabaharCoasts.

Methods:After sampling, antimicrobial and antifungal effects of ethanolic extract of red algae Gracilariaarcuataagainst 5 bacterial strains of Proteus vulgaris, Vibrio cholera, Escherichia coli, Staphylococcus aureus, Listeria monocytogenesandone fungal species,Aspergillusflavus, were studied and the results were compared with standard antibiotics. Independent sample t-test and one-way ANOVA were used for comparison between groups, and Duncan test was used to assess differences between means.

Results:V. cholera hadthe highest sensitivityto red algae with an inhibition zone diameter of 11.25±0.35, so that there was a statistically significant difference compared tocommercial antibiotic neomycin(p<0.05).E. coli showed the highest resistance against ethanolic extract ofthe test algae.

Conclusion:Red algaeGracilariaarcuata from Chabahar coasts has high antibacterial and antifungal properties.