title: Marine Sponge-DerivedStreptomycessp. SBT343 Extract Inhibits Staphylococcal Biofilm Formation.
abstract: Staphylococcus epidermidisandStaphylococcus aureusare opportunistic pathogens that cause nosocomial and chronic biofilm-associated infections. Indwelling medical devices and contact lenses are ideal ecological niches for formation of staphylococcal biofilms. Bacteria within biofilms are known to display reduced susceptibilities to antimicrobials and are protected from the host immune system. High rates of acquired antibiotic resistances in staphylococci and other biofilm-forming bacteria further hamper treatment options and highlight the need for new anti-biofilm strategies. Here, we aimed to evaluate the potential of marine sponge-derived actinomycetes in inhibiting biofilm formation of several strains ofS. epidermidis, S. aureus, andPseudomonas aeruginosa.Results fromin vitrobiofilm-formation assays, as well as scanning electron and confocal microscopy, revealed that an organic extract derived from the marine sponge-associated bacteriumStreptomycessp. SBT343 significantly inhibited staphylococcal biofilm formation on polystyrene, glass and contact lens surfaces, without affecting bacterial growth. The extract also displayed similar antagonistic effects towards the biofilm formation of otherS. epidermidisandS. aureusstrains tested but had no inhibitory effects towardsPseudomonasbiofilms. Interestingly the extract, at lower effective concentrations, did not exhibit cytotoxic effects on mouse fibroblast, macrophage and human corneal epithelial cell lines. Chemical analysis by High Resolution Fourier Transform Mass Spectrometry (HRMS) of theStreptomycessp. SBT343 extract proportion revealed its chemical richness and complexity. Preliminary physico-chemical characterization of the extract highlighted the heat-stable and non-proteinaceous nature of the active component(s). The combined data suggest that theStreptomycessp. SBT343 extract selectively inhibits staphylococcal biofilm formation without interfering with bacterial cell viability. Due to absence of cell toxicity, the extract might represent a good starting material to develop a future remedy to block staphylococcal biofilm formation on contact lenses and thereby to prevent intractable contact lens-mediated ocular infections.
authors.affiliation: Institute for Molecular Infection Biology, University of Würzburg Würzburg, Germany.
authors.forename: Srikkanth
authors.initials: S
authors.lastname: Balasubramanian
authors.affiliation: Institute of Pharmacology and Toxicology, University of WürzburgWürzburg, Germany; Department of Analytical Chemistry, Faculty of Pharmacy, Minia UniversityMinia, Egypt.
authors.forename: Eman M
authors.initials: EM
authors.lastname: Othman
authors.affiliation: Department of Ophthalmology, University Hospital Würzburg Würzburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kampik
authors.affiliation: Institute of Pharmacology and Toxicology, University of Würzburg Würzburg, Germany.
authors.forename: Helga
authors.initials: H
authors.lastname: Stopper
authors.affiliation: GEOMAR Helmholtz Centre for Ocean Research, RD3 Marine Microbiology, and Christian-Albrechts University of Kiel Kiel, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Hentschel
authors.affiliation: Institute for Molecular Infection Biology, University of Würzburg Würzburg, Germany.
authors.forename: Wilma
authors.initials: W
authors.lastname: Ziebuhr
authors.affiliation: Institute for Molecular Infection Biology, University of Würzburg Würzburg, Germany.
authors.forename: Tobias A
authors.initials: TA
authors.lastname: Oelschlaeger
authors.affiliation: Department of Botany II, Julius-von-Sachs Institute for Biological Sciences, University of WürzburgWürzburg, Germany; Department of Pharmacognosy, Faculty of Pharmacy, Minia UniversityMinia, Egypt.
authors.forename: Usama R
authors.initials: UR
authors.lastname: Abdelmohsen
keywords: Streptomyces; actinomycetes; biofilms; contact lens; marine sponges; staphylococci