Doesn’t E. coli cause food poisoning? If E. coli is so dangerous, why are they being used in labs?

  • Normal E. coli colonize the lower intestine of humans, while producing Vitamin K and protecting infection from other harmful bacteria.
  • Only some strains of E. coli cause food poisoning, but our group is using a harmless, nonpathogenic strain. This train is engineered to contain mutations that would not allow the E. coli to survive outside the lab without particular nutrients.
  • E. coli provides a well-studied and well-known model system to test and troubleshoot new trials on.


What if plasmids containing antibiotic resistance genes were released into the environment despite precautions?

  • These genes are used in synthetic biology as selection tools.
  • There are lower chances of gene uptake by wild bacteria compared to lab-strain bacteria which have perforated membranes.
  • In the case that wild bacteria did uptake the antibiotic resistance gene, that gene would eventually be lost in the population without exposure to the antibiotic, because it is then a disadvantage for the bacteria to carry the unused plasmids. (Evidence observed in past with the decline of specific antibiotic resistance after the human population limited that antibiotic).