Biofilm Architectural Breakdown in Response to Antibiotics Facilitates Community Invasion

Abstract

<p>Bacterial cells are often exposed to stress by changes in their environment. During the last decades the response of isolated cells to stress has been investigated in great detail. By contrast, little is known about the emergent multicellular level responses to stress, such as antibiotic exposure. Studying responses at the community level is key to understand the structure and function of the most common bacterial state: the multicellular communities termed biofilms. Here, by analysing <em>Vibrio cholerae</em> biofilms exposed to all different classes of antibiotics with single-cell resolution, we found that inhibition of protein synthesis cause striking changes in cell volume and biofilm architecture. The observed changes in cell volume are a single-cell level response driven by metabolic effects of the translational inhibition. The multicellular-level responses result from changes in matrix composition, matrix-cell dissociation and mechanical properties of the biofilms. We observed that these antibiotic-induced changes in biofilm architecture have strong consequences on the ecological dynamics of biofilms by making biofilms prone to invasion by bacteriophages and other bacterial cells. These mechanistic and ecological consequences of the emergent group-level architectural response to antibiotics are important to fully understand the ecological succession of biofilms and the implications of antibiotic therapy.</p>