Bacterial Biofilms

What’s a biofilm?

A biofilm is a structured community of microorganisms encapsulated within a self-developed polymeric matrix and adherent to a living or inert surface.

Biofilms are also often characterized by surface attachment, structural heterogeneity, genetic diversity, complex community interactions, and an extracellular matrix of

polymeric substances.

Examples

Biofilms are ubiquitous.

Biofilms can be found on rocks and pebbles at the bottom of most streams or rivers and often form on the surface of stagnant pools of water.

Biofilms grow in hot, acidic pools in Yellowstone National Park (USA) and on glaciers in Antarctica.

Biofilms in showers (Legionella).

Plaque formation on teeth.

Why a biofilm?

AdvantagesProtects the bacteria

AntibioticsPhagocytisedMetabolically inactiveSecretes virulence factors

Pseudomonas aeruginosa

Gram negative rod

Opportunistic pathogen

Fluoresces on certain types of agar

Prevalent in Hospitals due to it resistance to disinfectants

Particular problem in the cystic fibrosis community

Antibiotic resistant

Forms biofilms

Biofilm formation

Development initiates:plank tonic attached to biotic or abiotic surfaces.

Cells undergo a program of physiological changes involving Quorum sensing.

Production of copious quantities of extracellular polysaccharides.

Our Interest

Macrophage migration inhibitory factor (MIF)Enhance Pseudomonas aeruginosa growth both in vivo & in vitro

HypothesisMIF enhances biofilm formation

Culture Pseudomonas aeruginosa+/-MIF +/- OxygenBiofilm formation

Resazurin assay

Micro Arrays looking at gene expression

Possibilities

Target MIF therapeutically?InhibitorsDisrupt biofilm formationAntibiotics time to work

New antimicrobial defence for CF patients