Pharmaceuticals as Antifoulants: Inhibition of Growth and Effects on Adhesion of Marine Bacteria
Pharmaceuticals have potential as anti-biofouling agents in the marine environment but their effect on marine bacteria is poorly understood. We examined the effect of non-antibiotic pharmaceuticals on the growth and adhesion of marine bacteria found in biofilms. Bacterial strains isolated from tropical marine surfaces were tested. Twenty-five pharmaceutical compounds with a variety of primary mechanisms of action in vertebrates were tested for their ability to inhibit bacterial growth of 25 strains from13 genera. Fourteen compounds inhibited at least one strain. All strains were inhibited by at least one compound. The 5 most potent pharmaceuticals amlodipine besylate (NorvascTM), propranolol, fluoxetine (ApofluoxetineTM), prochlorperazine, sertraline (ZoloftTM) and trifluoperazine inhibited growth of the vast majority of strains. A set of 19 pharmaceuticals, with a range of bacteriacidal properties were tested for their affect on bacterial adhesion. The most potent anti-adhesion compounds were one that was broadly bactericidal, sertaline hydrochloride (Zoloft), and two that had no effect on growth: ondansetron hydrochorlide (Zofran) and olanzapine (Zyprexa). Pharmaceuticals with bactericidal activity and ability to inhibit adhesion may be useful in blocking biofilm formation, an important apect for the delivery of compounds that inhibit settlement or adhesion of macrofoulers. As the pharmaceuticals are engineered to be taken by mouth, the present forms are too stable for widespread use. In future studies we will deengineer candidate compounds to improve their degradability.
