title: Streptomycin favors biofilm formation by altering cell surface properties.
abstract: Studies have shown that external stress induces biofilm formation, but the underlying details are not clearly understood. This study investigates the changes in cell surface properties leading to increase in biofilm formation by Staphylococcus aureus and Pseudomonas aeruginosa in the presence of streptomycin. Bacterial attachment in the presence and absence of streptomycin was quantified by fluorescence spectroscopy. In addition, cell surface charge and contact angle were measured and the free energy barrier for attachment was modeled using extended Derjaguin-Landau-Verwey-Overbeek (xDLVO) theory. Peptides from bacterial cell surface were shaved by protease treatment and identified with ultra-performance liquid chromatography (UPLC)-QTOF and a homology search program SPIDER. Biofilm formation increased significantly in the presence of streptomycin (10 mg/L) in the culture. Bacterial cell surface charge reduced, and hydrophobicity increased leading to a net decrease in the free energy barrier for attachment. Extracellular matrix-binding protein was positively regulated in S. aureus under stress, indicating stronger interaction between bacterial cells and solid surface. In addition, several other proteins including biofilm regulatory proteins, multidrug efflux pumps, transporters, signaling proteins, and virulence factors were differentially expressed on bacterial cell surface, which is indicative of a strong stress response by bacteria to streptomycin treatment.
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive, 4, Singapore, 117585, Singapore.
authors: Amit
authors: A
authors: Kumar
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive, 4, Singapore, 117585, Singapore. chetyp@nus.edu.sg.
authors: Yen-Peng
authors: YP
authors: Ting
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism*; D001422:Bacterial Adhesion / Q000187:drug effects; D001426:Bacterial Proteins / Q000032:analysis; D018441:Biofilms / Q000254:growth & development*; D020869:Gene Expression Profiling; D008565:Membrane Proteins / Q000032:analysis; D011500:Protein Synthesis Inhibitors / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000502:physiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology; D013307:Streptomycin / Q000378:metabolism*; D013499:Surface Properties / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D008565:Membrane Proteins; D011500:Protein Synthesis Inhibitors; D013307:Streptomycin
keywords: Biofilm; Pseudomonas aeruginosa; Staphylococcus aureus; Stress; Surface proteins; xDLVO