Division of Critical Care Medicine, Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Seattle, Washington, USA.
Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA.
Infect Immun. 2023 Mar 15;91(3):e0053822. doi: 10.1128/iai.00538-22. Epub 2023 Feb 27.
Staphylococcus aureus generates biofilms during many chronic human infections, which contributes to its growth and persistence in the host. Multiple genes and pathways necessary for S. aureus biofilm production have been identified, but knowledge is incomplete, and little is known about spontaneous mutations that increase biofilm formation as infection progresses. Here, we performed selection of four S. aureus laboratory strains (ATCC 29213, JE2, N315, and Newman) to identify mutations associated with enhanced biofilm production. Biofilm formation increased in passaged isolates from all strains, exhibiting from 1.2- to 5-fold the capacity of parental lines. Whole-genome sequencing identified nonsynonymous mutations affecting 23 candidate genes and a genomic duplication encompassing Six candidate genes significantly impacted biofilm formation as isogenic transposon knockouts: three were previously reported to impact S. aureus biofilm formation (, , and ), while the remaining three (, , and ) were newly implicated by this study. Plasmid-mediated genetic complementation of , , and transposon mutants corrected biofilm deficiencies, with high-level expression of and further enhancing biofilm formation over basal levels. This work recognizes genes not previously identified as contributing to biofilm formation in S. aureus and reveals genetic changes able to augment biofilm production by that organism.
金黄色葡萄球菌在许多慢性人类感染中会生成生物膜，这有助于其在宿主中生长和持续存在。已经确定了金黄色葡萄球菌生物膜生成所需的多个基因和途径，但知识并不完整，并且对于随着感染的进展而增加生物膜形成的自发突变知之甚少。在这里，我们对四个金黄色葡萄球菌实验室菌株（ATCC 29213、JE2、N315 和 Newman）进行了选择，以鉴定与增强生物膜生成相关的突变。来自所有菌株的传代分离株的生物膜形成增加，其形成能力是亲本系的 1.2-5 倍。全基因组测序确定了影响 23 个候选基因的非同义突变和包含 6 个候选基因的基因组重复，这些基因对生物膜形成有重大影响，作为同基因转座子敲除：其中三个先前被报道影响金黄色葡萄球菌生物膜形成（ ， 和 ），而其余三个（ ， 和 ）则被本研究新发现。质粒介导的遗传互补转座子突变体的 、 和 纠正了生物膜缺陷， 和 的高表达水平进一步提高了生物膜形成水平，超过了基础水平。这项工作识别了以前未被鉴定为参与金黄色葡萄球菌生物膜形成的基因，并揭示了能够增加该生物生物膜生成的遗传变化。
