Inhibition of Virulence Gene Expression in Staphylococcus aureus by Novel Depsipeptides from a Marine Photobacterium

Marine Drugs

Maria Mansson³  Anita Nielsen¹  Louise Kjærulff⁴  Charlotte H. Gotfredsen⁴  Matthias Wietz²  Hanne Ingmer¹  Lone Gram² 

[1] Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, DK-1870 Frederiksberg C, Denmark;National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark;Center for Microbial Biotechnology, Department of Systems Biology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark;Department of Chemistry, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark;

关键词: Photobacterium;    Vibrionaceae;    antivirulence;    quorum sensing inhibition;    agr;   

DOI  :  10.3390/md9122537

来源: mdpi

【 摘 要 】

During a global research expedition, more than five hundred marine bacterial strains capable of inhibiting the growth of pathogenic bacteria were collected. The purpose of the present study was to determine if these marine bacteria are also a source of compounds that interfere with the agr quorum sensing system that controls virulence gene expression in Staphylococcus aureus. Using a gene reporter fusion bioassay, we recorded agr interference as enhanced expression of spa, encoding Protein A, concomitantly with reduced expression of hla, encoding α-hemolysin, and rnaIII encoding RNAIII, the effector molecule of agr. A marine Photobacterium produced compounds interfering with agr in S. aureus strain 8325-4, and bioassay-guided fractionation of crude extracts led to the isolation of two novel cyclodepsipeptides, designated solonamide A and B. Northern blot analysis confirmed the agr interfering activity of pure solonamides in both S. aureus strain 8325-4 and the highly virulent, community-acquired strain USA300 (CA-MRSA). To our knowledge, this is the first report of inhibitors of the agr system by a marine bacterium.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.