Scientific Publications
Campylobacter jejuni biofilms contain extracellular DNA and are sensitive to DNase I treatment
Frontiers in Microbiology, 6, 699
Biofilm formation is an important mechanism contributing to survival and transmission of bacterial pathogens in the food chain. The human pathogen Campylobacter jejuni is known to form biofilms in vitro in food chain relevant conditions, but the exact roles and composition of the extracellular matrix (ECM) composition are still no clear. Extracellular DNA (eDNA) has been found in many bacterial biofilms and can be a major ECM-component. Here we show that eDNA is also an essential component of the C. jejuni biofilm attached to stainless steel surfaces, in aerobic conditions and on heavily conditioned surfaces. Degradation of the eDNA by exogenous addition of DNase I led to rapid biofilm removal, without loss of C. jejuni viability. Following treatment of a surface with DNase I, C. jejuni is unable to re-establish a biofilm population within 48 hours. Addition of C. jejuni DNA containing an antibiotic resistence marker resulted in transfer of the antibiotic resistance marker to susceptible cells in the biofilm, presumably by natural transformation. Taken together these results suggest that eDNA is not only an essential component in C. jejuni biofilm formation, and its subsequent food chain survival, but may also able to contribute to the spread of antimicrobial resistance in C. jejuni. The degradation of eDNA with enzymes such as DNase I is a rapid method of C. jejuni biofilm removal, and is likely to potentiate the activity of antimicrobial treatments and thus synergistically aid disinfection treatments.
Frontiers in Microbiology, 6, 699
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