Antibacterial activity of the sea cucumber Holothuria leucospilota whole body extract against Staphylococcus aureus strains MRSA, SEA, and SEB

Aquatic organisms are a source of organic compounds that hold various features such as medical and nutritional activities. Within the framework of an antimicrobial activity study of marine macro-organisms from the Persian Gulf, bioactive compounds of the sea cucumber Holothuria leucospilota were extracted from the whole body using chloroform and methanol. The extracts were evaluated for their antibacterial effects against methicillin-resistant (MRSA) and staphylococcal enterotoxins producing (SEA, SEB) Staphylococcus aureus strains. Activities have been determined using three methods: disk diffusion tests, minimum bactericidal concentration (MBC), and minimum inhibitory concentration (MIC). The results demonstrate that methanol and chloroform extracts have an inhibitory effect on the growth of all strains at MIC concentrations up to 100 mg/ml. Also, chloroform extracts demonstrate bactericidal activity against SEB in concentrations of about 100 mg/ml. The extracts also show bactericidal effects against MRSA and SEB below 100 mg/ml concentrations. The highest antibacterial activity was found in methanol extract. Therefore, sea cucumber extracts are good candidates for the identification of new antimicrobials. Yet, comprehensive investigations are needed to separate and identify the active components for Holothuria leucospilota from the Persian Gulf.