文章基本信息

标题：Probiotic Escherichia coli inhibits biofilm formation of pathogenic E. coli via extracellular activity of DegP
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作者：Kuili Fang ; Xing Jin ; Seok Hoon Hong 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2018
卷号：8
期号：1
页码：4939
DOI：10.1038/s41598-018-23180-1
语种：English
出版社：Springer Nature
摘要：Many chronic infections involve bacterial biofilms, which are difficult to eliminate using conventional antibiotic treatments. Biofilm formation is a result of dynamic intra- or inter-species interactions. However, the nature of molecular interactions between bacteria in multi-species biofilms are not well understood compared to those in single-species biofilms. This study investigated the ability of probiotic Escherichia coli Nissle 1917 (EcN) to outcompete the biofilm formation of pathogens including enterohemorrhagic E. coli (EHEC), Pseudomonas aeruginosa, Staphylococcus aureus, and S. epidermidis. When dual-species biofilms were formed, EcN inhibited the EHEC biofilm population by 14-fold compared to EHEC single-species biofilms. This figure was 1,100-fold for S. aureus and 8,300-fold for S. epidermidis; however, EcN did not inhibit P. aeruginosa biofilms. In contrast, commensal E. coli did not exhibit any inhibitory effect toward other bacterial biofilms. We identified that EcN secretes DegP, a bifunctional (protease and chaperone) periplasmic protein, outside the cells and controls other biofilms. Although three E. coli strains tested in this study expressed degP, only the EcN strain secreted DegP outside the cells. The deletion of degP disabled the activity of EcN in inhibiting EHEC biofilms, and purified DegP directly repressed EHEC biofilm formation. Hence, probiotic E. coli outcompetes pathogenic biofilms via extracellular DegP activity during dual-species biofilm formation.