Our team has used two bacterial chassis for our experiments. Escherichia coli strains DH5 alpha (for DNA work) and BL21 (DE3; our expression strain). Both of these strains are risk group 1 organisms which do not cause disease in healthy adult humans. Our genetically engineered bacteria will pose no risk to humans as both strains have been developed to not produce toxins and cannot survive in the human digestive system. However, when working with GMOs containment is also an issue. This is because any cells that manage to get into the environment could have wide-ranging effects on our ecosystem via the transmission of genes across/within species, such as antibiotic resistance.
Fortunately, both BL21 (DE3) and K12 strain derivatives such as DH5 alpha are attenuated, meaning that many genes/pathways that would confer a selective advantage in the environment have been removed. Even so, our lab team has taken the necessary precautions when conducting research to ensure that we have kept our bacteria contained. We wear coats and disposable gloves when working in the lab, all cultured bacteria are disposed of with Virkon and autoclaved. We have spill kits in the lab, as well as safety showers and fire extinguishers, and follow all standard PC1 (i.e. BSL1) containment procedures.
