Extracellular DNA (eDNA) is an important component of biofilm matrix that serves to maintain biofilm structural integrity, promotes genetic exchange within the biofilm, and provides protection against antimicrobial compounds. Advances in microscopy techniques have provided evidence of the cobweb- or lattice-like structures of eDNA within biofilms from a range of environmental niches. However, methods to reliably assess the abundance and architecture of eDNA remain lacking. This study aimed to address this gap by development of a novel, high-throughput image acquisition and analysis platform for assessment of eDNA networks in situ within biofilms. Utilizing Streptococcus gordonii as the model, the capacity for this imaging system to reliably detect eDNA networks and monitor changes in abundance and architecture (e.g., strand length and branch number) was verified. Evidence was provided of a synergy between glucans and eDNA matrices, while it was revealed that surface-bound nuclease SsnA could modify these eDNA structures under conditions permissive for enzymatic activity. Moreover, cross talk between the competence and hexaheptapeptide permease systems was shown to regulate eDNA release by S. gordonii. This novel imaging system can be applied across the wider field of biofilm research, with potential to significantly advance interrogation of the mechanisms by which the eDNA network architecture develops, how it can influence biofilm properties, and how it may be targeted for therapeutic benefit.
|Number of pages||18|
|Journal||Applied and Environmental Microbiology|
|Early online date||13 Jun 2022|
|Publication status||E-pub ahead of print - 13 Jun 2022|
Bibliographical noteFunding Information:
This work was funded by The Dunhill Medical Trust (RPGF1810\101). We acknowledge support from the Wolfson Bioimaging Facility and BrisSynBio, a BBSRC/EPSRC-funded Synthetic Biology Research Centre (grant number BB/L01386X/1).
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