Ex vivo Pig Lung Model of Biofilm: A Technique to Develop Lung Model to Study Bacterial Biofilms on Pig Bronchiolar Tissue

Bronchioles are the tubular airways of the lungs. During chronic infection, the bronchioles get clogged due to the accumulation of mucus. The nutrient-rich mucus provides a suitable environment for opportunistic bacteria to grow. These bacteria get embedded in a self-produced extracellular polymeric matrix and proliferate to form a biofilm.

To mimic bacterial biofilm development on the lungs, take a pig bronchiolar tissue specimen in a Petri dish. Dissect the tissue into pieces of the desired shape. Add a biofilm culture media to the Petri dish. Sterilize the dish under UV light to remove any surface contaminants.

Transfer the sterilized tissue pieces into a multiwell plate containing biofilm culture media and agarose pads, which serve as an optimum substrate for bacterial adhesion. Next, prick a needle tip containing a colony of the desired bacteria onto each tissue piece to introduce planktonic bacteria into the tissue. Seal the plate with a UV-sterilized, porous membrane that eases uniform oxygen exchange throughout the plate surface. Incubate the sealed plate. 

During incubation, bacteria adhere irreversibly to the epithelial surface through pili and begin to secrete the extracellular matrix.  Within the matrix, bacteria utilize the energy sources, mucin, and free DNA from the culture media to form biofilms. The bacterial biofilm model is ready for further testing.