Signaling and self-organization in bacterial biofilms
Fig. 1. P. aeruginosa cells ordered in a square 9x9 laser trap array in growth media. This array can be studied as is or ‘printed’ onto a specific surface.
Chronic bacterial infections are the major cause of death in cystic fibrosis (CF). In such chronic infections, antibiotic-resistant bacterial biofilms are formed in the lungs of CF patients. At present, no good animal model for such chronic infections exists. Biofilms are poorly understood due in part to the inherent complexity in biofilm formation, which is compounded by our inability to control and manipulate development of completely identical biofilm structures. We address this need by exploiting recent advances in physics, chemistry, and bacteriology to make user-defined laser-generated patterns of genetically-modified individual bacteria, and aim to understand how quorum sensing and its immediate downstream consequences eventually lead to antimicrobial-resistant biofilms. The long-term goal is the rational design of anti-biofilm therapeutic strategies informed by a fundamental understanding of biofilm formation.
Massively-parallel laser tweezers based on acousto-optic deflectors are employed to dynamically generate reproducible arrays of bacteria in user-defined spatial patterns at the single bacterium level. We use mutant strains of P. aeruginosa to study ‘quorum sensing’ and its downstream consequences in bacterial colonies, to see how these signals are eventually expressed in morphological and phenotypic changes, such as antimicrobial resistance.