Zhang Tianqi, Ray Sanhita, Melican Keira, Richter-Dahlfors Agneta
AIMES-Center for the Advancement of Integrated Medical and Engineering Sciences, Karolinska Institutet and KTH Royal Institute of Technology, SE-171 77, Stockholm, Sweden.
Department of Neuroscience, Karolinska Institutet, SE-171 77, Stockholm, Sweden.
Biofilm. 2024 Jul 6;8:100212. doi: 10.1016/j.bioflm.2024.100212. eCollection 2024 Dec.
Urinary tract infections (UTI) caused by uropathogenic (UPEC) are a significant global health challenge. The UPEC biofilm lifestyle is believed to play an important role in infection recurrency and treatment resistance, but our understanding of how the extracellular matrix (ECM) components curli and cellulose contribute to biofilm formation and pathogenicity is limited. Here, we study the spatial and temporal development of native UPEC biofilm using agar-based detection methods where the non-toxic, optically active fluorescent tracer EbbaBiolight 680 reports the expression and structural location of curli in real-time. An screen of the biofilm capacity of common UPEC strains reveals significant strain variability and identifies UPEC No. 12 (UPEC12) as a strong biofilm former at 28 °C and 37 °C. Non-interventional microscopy, including time-lapse and 2-photon, reveal significant horizontal and vertical heterogeneity in the UPEC12 biofilm structure. We identify region-specific expression of curli, with a shift in localization from the bottom of the flat central regions of the biofilm to the upper surface in the topographically dramatic intermediate region. When investigating if the rdar morphotype affects wettability of the biofilm surface, we found that the nano-architecture of curli guided by cellulose, rather than the rdar macrostructures, leads to increased hydrophobicity of the biofilm. By providing new insights at exceptional temporal and spatial resolution, we demonstrate how non-interventional analysis of native biofilms will facilitate the next generation of understanding into the roles of ECM components during growth of UPEC biofilms and their contribution to the pathogenesis of UTI.
由尿路致病性大肠杆菌（UPEC）引起的尿路感染（UTI）是一项重大的全球健康挑战。人们认为UPEC的生物膜生活方式在感染复发和治疗耐药性方面起着重要作用，但我们对细胞外基质（ECM）成分卷曲菌毛和纤维素如何促进生物膜形成和致病性的了解有限。在这里，我们使用基于琼脂的检测方法研究天然UPEC生物膜的时空发育，其中无毒、具有光学活性的荧光示踪剂EbbaBiolight 680实时报告卷曲菌毛的表达和结构位置。对常见UPEC菌株的生物膜形成能力进行的筛选揭示了显著的菌株变异性，并确定UPEC 12号菌株（UPEC12）在28°C和37°C时是一种强大的生物膜形成菌。包括延时和双光子在内的非介入性显微镜观察揭示了UPEC12生物膜结构中显著的水平和垂直异质性。我们确定了卷曲菌毛的区域特异性表达，其定位从生物膜平坦中心区域的底部转移到地形变化显著的中间区域的上表面。在研究rdar形态型是否影响生物膜表面的润湿性时，我们发现由纤维素引导的卷曲菌毛的纳米结构，而不是rdar宏观结构，导致生物膜疏水性增加。通过在特殊的时空分辨率下提供新的见解，我们证明了对天然生物膜的非介入性分析将如何促进对ECM成分在UPEC生物膜生长过程中的作用及其对UTI发病机制的贡献的下一代理解。
