Penicillin G increases the synthesis of a suicidal marker (CidC) and virulence (HlgBC) proteins in Staphylococcus aureus biofilm cells

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• 作者：Kirsi Savijoki^a ; ^b ; ^c ; ^{kirsi.savijoki@helsinki.fi" class="auth_mail" title="E-mail the corresponding author} ; Malena Skogman^d ; Adyary Fallarero^d ; Tuula A. Nyman^b ; Antti Sukura^c ; Pia Vuorela^d ; Pekka Varmanen^a
• 关键词：Staphylococcus aureus ; Biofilm ; Penicillin G ; 2D DIGE ; CidC ; HlgBC
• 刊名：International Journal of Medical Microbiology
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：306
• 期：1
• 页码：69-74
• 全文大小：1221 K

文摘

The present study reports the effect of Penicillin G (PenG) on the proteome dynamics of the Staphylococcus aureus strain Newman during biofilm mode of growth. The viability of the 18-h-old biofilm cells challenged with PenG at the concentration of 1 mg mL⁻¹ was first assessed by plate counting, resazurin and LIVE/DEAD fluorescence staining, which indicated that the viability was reduced by ∼35% and ∼90% at 2 h and 24 h, respectively, after the addition of PenG. Subsequent two-dimensional difference gel electrophoresis (2D DIGE) assay of the treated and non-treated biofilm cells at the indicated time points revealed 45 proteins showing time- and treatment-specific change (1.5-fold, p < 0.01). The 2D DIGE results suggested that the PenG-induced decrease in viability was accompanied by an increased synthesis of pyruvate oxidase (CidC), a suicidal marker known to potentiate acetate-dependent cell death in S. aureus. Increased abundance was also found for the TCA cycle associated malate–quinone oxidoreductase (Mqo), the ClpC ATPase, the HlgBC toxin and phage-associated proteins, which suggests that surviving cells have induced these activities as a last effort to overcome lethal doses of PenG. Proteomic results also revealed that the surviving cells were likely to strengthen their peptidoglycan due to the increased abundance of cell-wall biogenesis associated proteins, FemA and Pbp2; a phenomenon associated with dormancy in S. aureus.