Biofilms are highly organized three-dimensional microbial communities that grow surface-associated.
Confocal microscopy image of a bacterial biofilm. The "mounds" in the image, known as 'microcolonies', are not single cells, but are composed of aggregates of countless bacteria.
Biofilm growth represents a majority of the natural format of growth in the microbes' respective natural environments. They are adherent to the surfaces onto which the cells have established their biofilms, are often multi-species and/or genetic diversity, and are encapsulated by extracellular polymeric substances, or the matrix. Biofilms are believed to be an important part of microbial developmental life cycles where they establish a stable niche on a surface. Some cells are then released from the biofilms, which as planktonic cells, colonize a new niche wherein they establish a new biofilm.
Biofilms growths are very different from how microbiologists have traditionally grown these organisms in shaken liquid cultures. It is typically reported in all species studied, that the sets of gene expressed between biofilm and liquid cultures can be 20% - 80% different. Biofilms are typically highly resistant to antibiotics and foster greater genetic diversity, thus seemingly promoting particular evolutionary changes. Most antimicrobial agents from the past and present are discovered and tested on non-biofilm cells. Perhaps this plays a great role in our modern inability to control chronic bacterial biofilm infections in medicine, and biofouling costs our industries billions of dollars annually.
So exactly how much do we really understand about bacteria when we might not have been paying attention to how they actually grow in their environments?
This is what our lab is principally interested in addressing. We use a variety of scientific tools and techniques, and engage in international multi-disciplinary collaborations to take our appreciation of bacteriology to the next level. We primarily study two bacterial species: Pseudomonas aeruginosa and Bordetella bronchiseptica, both pathogenic in their own rights, to help us understand biofilm biology.