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Bacterial biofilms pose serious problems in medical and industrial settings. One of the major societal challenges lies in the increasing resistance of bacteria against biocides used in antimicrobial treatments, e.g., via overabundant use in medicine, industry, and agriculture or cleaning and disinfection in private households. Hence, new efficient bacteria‐repellent strategies avoiding the use of biocides are strongly desired. One promising route to achieve bacteria‐repellent surfaces lies in the contactless and aseptic large‐area laser‐processing of technical surfaces. Tailored surface textures, enabled by different laser‐processing strategies that result in topographic scales ranging from nanometers to micrometers may provide a solution to this challenge. This article presents a current state‐of‐the‐art review of laser‐surface subtractive texturing approaches for controlling the biofilm formation for different bacterial strains and in different environments. Based on specific properties of bacteria and laser‐processed surfaces, the challenges of anti‐microbial surface designs are discussed, and future directions will be outlined. [ABSTRACT FROM AUTHOR]

In bacterial biofilms, which are often involved in chronic infections, cells are surrounded by a self-produced extracellular matrix that contains amyloid fibres, exopolysaccharides and other biopolymers. The matrix contributes to the pronounced resistance of biofilms against antibiotics and host immune systems. Being highly inflammatory, matrix amyloids such as curli fibres of Escherichia coli can also play a role in pathogenicity. Using macrocolony biofilms of commensal and pathogenic E. coli as a model system, we demonstrate here that the green tea polyphenol epigallocatachin gallate (EGCG) is a potent antibiofilm agent. EGCG virtually eliminates the biofilm matrix by directly interfering with the assembly of curli subunits into amyloid fibres, and by triggering the σE cell envelope stress response and thereby reducing the expression of CsgD - a crucial activator of curli and cellulose biosynthesis - due to csgD mRNA targeting by the σE-dependent sRNA RybB. These findings highlight EGCG as a potential adjuvant for antibiotic therapy of biofilm-associated infections. Moreover, EGCG may support therapies against pathogenic E. coli that produce inflammatory curli fibres along with Shigatoxin. [ABSTRACT FROM AUTHOR]