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How Worried Should You Be About Bacteria?
A microbiologist explains the bacteria featured in John Green’s “Turtles All the Way Down”
Disclaimer: This article does not contain major spoilers from the movie.
The 2024 film adaptation of John Green’s young adult novel, Turtles All the Way Down, centers on Aza Holmes, a germaphobe with obsessive-compulsive disorder (OCD). She is haunted by images that bacteria are lurking everywhere, eager to invade her body and wreak havoc. Aza’s intense fear of infection hinders her social life and takes a toll on her mental health.
As a microbiologist at the Indiana University School of Medicine, I’d like to use John Green’s popular story as an opportunity to elaborate on bacteria and our relationship to these organisms. Are Aza’s fears of bacteria warranted? Are all bacteria bad for us? What can we do to avoid infection?
A short history of bacteria
Bacteria were first observed in 1676 by Antoni van Leeuwenhoek, a draper who made the most powerful microscope at the time. He was the first to see and describe a wide assortment of microbes in a variety of samples from pond water to dental plaque.
Two hundred years later, Louis Pasteur conducted experiments supporting the Germ Theory of Disease, which proposed that microbes could make people sick. Shortly thereafter, Robert Koch conclusively showed that bacteria can cause anthrax and other infectious diseases. With the understanding that bacteria can be a source of illness, scientists began making new discoveries to prevent and cure bacterial infections.
While Aza seemed fixated on bacteria, there are other types of infectious agents that cause illness, such as viruses, fungi, protozoan parasites, and worms. In one scene, Aza expressed concern about Giardia. Giardia is a protozoan parasite that causes diarrhea when ingested. It can be acquired from contaminated water or contact with feces from an infected person.
Are all bacteria our enemy?
The movie often implies that bacteria in general are a dangerous threat to health. They are described as “parasites,” which implies that they receive benefits from us without…
