프로테오믹스 기법을 이용한 황색포도알균의 biofilm 형성 관련 단백체 동정 및 기능분석에 관한 연구

초록

Purpose : Staphylococcus is the causative agent of a wide range of disease and its biofilm-forming ability is the major cause of chronic polymer-associated infection. Biofilm cells evade host immune response and show a higher resistance to antibiotics. To reveal the biofilm growth and its pathogenesis factors, we performed the comparative proteomic and transcriptomic analysis of induced vancomycin resistant S. aureus biofilm and planktonic cells. Also antibiotics effects on biofilm cells and planktonic cells were investigated to improve antibiotic therapy for patients with biofilm-associated infections. Methods : Combined approach of two-dimensional electrophoresis and MS analysis was used to identify cell wall associated proteins expressed in induced vancomycin resistant S. aureus biofilm and planktonic cells after 48h of growth. Also transcriptomic profiling was compared under the same growth conditions. And we assessed the effect of antimicrobial agents against grown planktonically and as bioflms. Results : Biofilm cells expressed higher levels of proteins associated with lipid metabolism such as mevalonate kinase(MVaK1), biotin carboxylase subunit of acetyl—CoA carboxylase(AccC) and adaption to atypical condition such as capsular polysaccharide enzymes. Biofilm cells express more RsbU and sigma factor B, which corroborates the positive effect on biofilm development. Furthermore, biofilm cells expressed more virulence and defense mechanism related proteins such as immunodominant antigen A(IsaA), Xaa-Pro peptidase, trigger factor and similar to SceD precursor. In biofilm cells, toxins, fibrinogen-binding protein, gap were up-regulated >2 fold higher than planktoinc cells. Especially gene expression level of immunoglobulin G binding protein A precursor(>17 fold higher) shows that metabolic activity change in immune defense system of biofilm cells. And MBIC_(90) and MBBC_(90) of tigecycline showed 2-fold and 512-fold reduction respectively. Conclusions : Our results suggest that the cell wall associated proteins identified herein likely contribute for the biofilm formation and pathogenesis. The functional proteomics and tigecycline therapy effect on bioflims should be further studied for control staphylococcal biofilm-associated infections.

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