Microbiology Services – Quantitative Biofilm Service Assay
Microbial biofilms are everywhere. Biofilm formation occurs when planktonic cells (bacteria, yeast, fungi, etc) attach and colonize living or non-living surfaces. Plaque on your teeth, slime on the rocks by the river, or the layers of film on the boat hull are a few examples. In some instances, biofilm can be utilized for constructive purposes, such as in microbial fuel cells to generate electricity or even in bioremediation to help eliminate pollutants from contaminated soil or marine systems. Unfortunately, biofilm also have been implicated in numerous infectious diseases as biofilms are harder to eradicate. These include tooth decay and gum disease, urinary catheter infections as well as more lethal infections such as in cystic fibrosis, endocarditis, and infections on indwelling medical devices.
Biofilm bacteria are resistant to many antibiotics and disinfectants because they are encased by a glue-like substance, extracellular polysaccharide (EPS) which acts as a diffusion barrier. Biofilms also have the ability to resist phagocytosis and other innate immune defenses. Cell-cell communication through signaling molecules have been shown to be an important factor in biofilm formation. There is also a special cell state in the biofilm called ‘persisters’ or dormant cells that are less metabolically active than regular cells. Specialized microenvironment (varying levels of pH, oxygen, and nutrients) within biofilm also allows for different levels of cellular activity. Research has shown that bacterial biofilm regulate their behavior, simultaneously turning on different genes than their planktonic counterparts. These are only a few of the many explanations contributing to the reduced susceptibility of biofilms to antibiotics, with new hypotheses being investigated every day. That is why it is imperative to study biofilms and discover novel biofilm control strategies.
At EP, we have the expertise to test new antimicrobials for biofilm treatment. Established biofilm assays such as MBEC™ assay, CDC and drip flow biofilm reactor are available to assess antimicrobial activity against biofilm. MBEC assay which utilizes the Calgary Biofilm Device 96-well plate, allows for testing of multiple compounds and formulations. This assay provides fast turnaround time and reproducible results with reasonable pricing. The CDC biofilm reactor where biofilm is allowed to attach on 24 discs (½ inch diameter) can be modified to allow for biofilm formation and growth on various test surfaces. The drip flow reactor which allows biofilm to grow on a liquid-air interface can also utilize a variety of test surfaces. We also have the experience developing custom biofilm models, such as our in vitro catheterized bladder model where crystalline biofilm can be formed.
Dr. William (Bill) Costerton, recognized as the ‘Father of Biofilms’, was one of the first scientists to explore biofilm and its impacts in our daily lives. With more than 40 years of scientific contribution in numerous academic and research institutes, he had left behind an incredible scientific legacy for all of us. I had an amazing opportunity to have known him at the Center for Biofilm Engineering at Montana State University, and since then he had been a wonderful tutor in the world of biofilms. The memory of Dr. Costerton, who was my mentor and dear friend, will be remembered fondly.