Addie Unit Model
Updated: 11/29/2020
Addie Unit Model

Storyboard Text

  • Addie, like most kids, liked to play outdoors, where she could be exposed to millions of bacteria. Addie was also a scab-picker, allowing some bacteria, namely staph (staphylococcus), to infect her.
  • While only a few bacteria infected her, they were constantly multiplying, so within hours there were millions of harmful bacteria in her body.
  • After going to the hospital, the doctors found that the staph had damaged her lungs so badly that she needed to be put on a lung bypass machine called ECMO. While ECMO could save a person's life, there was also a high probability that it would introduce new infections to the body.
  • Addie got a bacterial infection called Steno (Stenotrophomonas), which was immune to all but 5 or 6 antibiotics. However when doctors tried them one by one, they would work for a week or two, and then the Steno would flare up again. At the end, they declared the Steno pan-resistant, meaning that it was resistant to everything.
  • What had happened was some small part of the Steno was resistant to the antibiotics, due to genetic mutation, which was why it seemed like the antibiotics would work; the rest of the Steno had been killed off. However, after a week, the resistant Steno (blue) would have multiplied many times over.
  • After the cycle was complete with all of the antibiotics, the only Steno left were pan-resistant. This is an example of natural selection, because only the bacteria with traits that allow them to survive the antibiotics would live and reproduce.