Early bacterial adhesion dynamics
When bacteria grow on solid surfaces, they can form three-dimensional communities called biofilms. Within these complex structures, bacteria can develop specific tolerance to different microbiocides, causing serious health and economic problems. Investigations of the key molecular events involved in biofilm formation have shown that surface-exposed adhesin proteins promote this process, but many questions remain regarding the mechanisms and biophysics of surface adhesion. A new paper introduces an original approach to investigating the very early steps in bacterial adhesion that uses dispersed colloidal surfaces as microbial adhesion substrates. Using flow cytometry, the authors performed a quantitative realtime analysis of adhesion kinetics of several strains of the bacterium Escherichia coli, which were genetically engineered to produce well-characterized cell-surface adhesins that are known to promote biofilm development. This provides evidence for previously unknown adhesin-dependent behaviors, such as clear-cut differences in the very initial phases of surface colonization, and demonstrates that initial adhesion correlates with almost instant surface property changes. Cell-to-cell association might serve as an amplification mechanism for surface colonization. This paper provides a new understanding of the intricate relationships between the physico-chemistry of abiotic surfaces and bacterial adhesion.
A short–time scale colloidal system reveals early bacterial adhesion dynamics. 2008 PLoS Biol 6(7): e167
The development of bacteria on abiotic surfaces has important public health and sanitary consequences. However, despite several decades of study of bacterial adhesion to inert surfaces, the biophysical mechanisms governing this process remain poorly understood, due, in particular, to the lack of methodologies covering the appropriate time scale. Using micrometric colloidal surface particles and flow cytometry analysis, we developed a rapid multiparametric approach to studying early events in adhesion of the bacterium Escherichia coli. This approach simultaneously describes the kinetics and amplitude of early steps in adhesion, changes in physicochemical surface properties within the first few seconds of adhesion, and the self-association state of attached and free-floating cells. Examination of the role of three well-characterized E. coli surface adhesion factors upon attachment to colloidal surfaces-curli fimbriae, F-conjugative pilus, and Ag43 adhesin-showed clear-cut differences in the very initial phases of surface colonization for cell-bearing surface structures, all known to promote biofilm development. Our multiparametric analysis revealed a correlation in the adhesion phase with cell-to-cell aggregation properties and demonstrated that this phenomenon amplified surface colonization once initial cell-surface attachment was achieved. Monitoring of real-time physicochemical particle surface properties showed that surface-active molecules of bacterial origin quickly modified surface properties, providing new insight into the intricate relations connecting abiotic surface physicochemical properties and bacterial adhesion. Hence, the biophysical analytical method described here provides a new and relevant approach to quantitatively and kinetically investigating bacterial adhesion and biofilm development.
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Tags: Bacteria, Biofilms, Biology, Microbiology, Science
You could possibly discuss the role of quorum sensing in this biofilm development. Nice article.