Messad Nourreddine, Prajsnar Tomasz K, Lina Gerard, O'Callaghan David, Foster Simon J, Renshaw Steve A, Skaar Eric P, Bes Michèle, Dunyach-Remy Catherine, Vandenesch François, Sotto Albert, Lavigne Jean-Philippe
National Institute of Health and Medical Research, Faculty of Medicine, University of Montpellier, Nîmes, France.
The Bateson Centre, University of Sheffield, Western Bank, Sheffield, U.K. Krebs Institute, University of Sheffield, Western Bank, Sheffield, U.K.
Diabetes. 2015 Aug;64(8):2991-5. doi: 10.2337/db15-0031. Epub 2015 Apr 21.
Staphylococcus aureus is an opportunistic bacterium capable of causing a wide range of severe diseases when it gains access to underlying tissues. Paradoxically, S. aureus is a common inhabitant of the skin microflora and colonizes the nares and other human mucosa. The purpose of this study was to determine the genetic basis for the differences in the pathogenic versus colonizing potential of S. aureus isolated from diabetic foot ulcers (DFUs). By performing optical map comparisons of a collection of S. aureus strains isolated from DFUs, we brought to light a prophage present in noninfecting bacteria. The phage, namely ROSA-like, was localized in a hotspot region ΦNM2 near the locus isd, the iron surface determinant system. The integrated phage significantly reduces the virulence of the strain and increases the biofilm formation. DFUs seem to be a specific niche of this colonizing strain. The ROSA-like phage represents the first description of a mobile element present mainly in S. aureus isolated from DFUs, which modulates the relationship of the bacteria with its human host. This phage appears to attenuate bacterial virulence and promote colonization.
金黄色葡萄球菌是一种机会致病菌，当它侵入深层组织时能够引发多种严重疾病。矛盾的是，金黄色葡萄球菌是皮肤微生物群的常见寄居菌，定植于鼻腔和其他人体黏膜。本研究的目的是确定从糖尿病足溃疡（DFU）分离出的金黄色葡萄球菌在致病潜力与定植潜力方面存在差异的遗传基础。通过对从DFU分离出的一组金黄色葡萄球菌菌株进行光学图谱比较，我们发现了一种存在于非感染性细菌中的前噬菌体。这种噬菌体名为ROSA样噬菌体，定位于铁表面决定簇系统（isd）位点附近的热点区域ΦNM2。整合的噬菌体显著降低了菌株的毒力并增加了生物膜的形成。DFU似乎是这种定植菌株的一个特定生态位。ROSA样噬菌体是首次对主要存在于从DFU分离出的金黄色葡萄球菌中的一种移动元件进行描述，该元件调节细菌与其人类宿主之间的关系。这种噬菌体似乎会减弱细菌的毒力并促进定植。
