Scientists from Harvard Medical School and Technion-Israel Institute of Technology have ingeniously visualized the Escherichia coli evolution through ever increasing amounts of antibiotics. Inspired by a Hollywood movie billboard, the team constructed the so called Microbial Evolution and Growth Arena i.e. MEGA plate to be able to monitor bacteria’s movement, survival and resistance.
In the course of 11 days, bacteria grew, adapted, mutated and survived through 10, 100 and even 1000 times as much antibiotic as the wild type can survive.
“One general law, leading to the advancement of all organic beings, namely, multiply, vary, let the strongest live and the weakest die.” Charles Darwin
When the growing bacteria reached the antibiotic concentration in which they could not survive, their spreading would stop until a smaller group adapted i.e. built their resistance through the successive accumulation of genetic changes, and started to spread further along the MEGA plate.
“Ultimately, in a dramatic demonstration of acquired drug resistance, bacteria spread to the highest drug concentration. In the span of 10 days, bacteria produced mutant strains capable of surviving a dose of the antibiotic trimethoprim 1,000 times higher than the one that killed their progenitors. When researchers used another antibiotic — ciprofloxacin — bacteria developed 100,000-fold resistance to the initial dose.” Harvard Gazette
Splice Summer Series brings you an interesting visualization of bacterial evolution and growth through the increasing amounts of antibiotics.
By Tea Pavlek, MSc BioSistemika LLC