antibacterial and antifungal activity of holothuria leucospilota isolated from persian gulf and oman sea

background: emergence of antimicrobial resistance toward a number of conventional antibiotics has triggered the search for antimicrobial agents from a variety of sources including the marine environment. objectives: the aim of this study was to evaluate the antimicrobial potential of holothuria leucospilota from qeshm and kharg islands against some selected bacteria and fungi. materials and methods: in this investigation, sea cucumbers from two coastal cities of persian gulf were collected in march and may 2011 and identified by the scale method according to the food and agriculture organization of the united nations. antibacterial activity of hydroalcoholic extracts of the body wall, cuvierian organs and coelomic fluid, methanol, chloroform, and n-hexane extracts of the body wall were evaluated by the spot test. in addition, their antifungal activity was assessed by the broth dilution method. results: the displayed effect was microbiostatic at concentrations of 1000 and 2000 µg/ml rather than microbicidal. the highest activity of hydroalcoholic extracts was exhibited by body wall, cuvierian organs and coelomic fluid against escherichia coli, salmonella typhi, staphylococcus aureus and pseudomonas aeruginosa; aspergillus niger, a. fumigatus, a. flavus and a. brasilensis. however, none of the methanol, chloroform and n-haxane extracts showed appreciable effects against shigella dysenteriae, proteus vulgaris, bacillus cereus, s. epidermidis and candida albicans. moreover, cuvierian organs did not possess any antifungal potential. conclusions: our data indicated that water-methanol extracts from the body wall of h. leucospilota possess antibacterial and antifungal activity. however, additional and in-depth studies are required to isolate and identify the active component(s).