The Relationship Between Viscosity and Increased Ampicillin Resistance in E. Coli

Antibiotic resistance in bacteria has become an increasingly significant issue in modern medicine. Despite the regularity of antibiotic resistance, there is still much we do not know about the mechanisms employed by resistant bacteria. One of the mechanisms ampicillin uses to attack E. Coli is to prevent the synthesis of the bacterial cell wall. Several studies, using an Atomic Force Microscope, have discovered that the cell walls of E. Coli become stiffer when they are cultured to be resistant to antibiotics. Here we measure the rheological properties of E. Coli with and without ampicillin in a motility buffer. We hypothesize that the increased stiffness on a cellular level will manifest as a collective property, changing the shear stress, viscosity, and modulus of the entire suspension. Our results taken from the rheometer indicate an increase in viscosity as the E. Coli bacteria become increasingly resistant to ampicillin.