In designing our E. coli based therapeutic, safety has always been a primary concern. We have implemented a number of precautions, both in our experimental design and in our lab practices, to ensure the safety of ourselves and others.
We have designed our project to minimize the risk of those inside the lab and out. Our chassis, E. coli Nissle 1917, is a non-pathogenic strain of E. coli that has been used in probiotic supplements, and is safe to work with. Our design precautions also extend to the possibility of our strain escaping from the lab. The bactericidal properties of our strain of Nissle are engineered to be specific to particular pathogenic bacteria, reducing the likelihood of harm to non-target bacteria. Further, because the bactericidal components we engineered take a heavy metabolic burden on our cells, our engineered traits are unlikely to persist through generations if our organisms were to ever escape from the lab. All of our conjugation machinery is on a plasmid that doesn’t conjugate itself, meaning that there is no risk of transmitting antibiotic resistances throughout a bacterial population.
While our chassis is not pathogenic, our target organisms, such as H. pylori, are. To avoid working with pathogenic bacteria, we have outsourced handling of H. pylori to a lab at the University of Oregon that has expertise in handling H. pylori and other pathogenic bacteria. While we never worked with pathogens over the summer, we suggest that future iGEM teams building on our work take similar precautions.
When putting these design elements into practice in the lab, we have been diligent in training team members in lab safety and following safety protocol. Everyone on our team working in the lab has received safety training, and are assisted by our lab safety lead, who makes sure safety protocols are being followed. Full PPE is worn at all times by team members in the lab and proper waste management protocol is consistently followed.