Microbiology is cool!

The room smelled like a trashcan does when it has not been taken out for a few days. Overall, an unpleasant smell, but a smell that brings me back to hours of extracting, purifying, and isolating my very own bacteriophage. So, regardless of the smell, I was excited. The prep work was done for us, and stacks and stacks of prepared Petri dishes lay in wait for their serving of bacteria. Each of us came into the room bearing our toothbrushes that were to be decapitated in the next few minutes. We murmured to each other about the surely terrible toothbrushes we would receive in compensation for giving up our toothbrushes for scientific research. An air of excitement and apprehension at the upcoming research project filled the air, or maybe I was just imagining that.

How do human habits regarding oral hygiene affect bacterial contamination? That was the research question at hand. The specific variables we were considering were: distance from the toilet, storage location, storage method, age, gender, toothbrush and toothpaste brand, and affiliation with OTS or a mere student. Not only do we have billions of microbes in our body, but they actually amount to ten times the amount of human cells we have! In fact, humans cannot be healthy without our microbiome, and when we do get sick, it often is a result of a disruption of the balance of our microbiome. So how did we get answers from a decapitated toothbrush and some Petri dishes filled with smelly media? Herein lies that story. After violently decapitating our precious toothbrushes with gardening shears, the bacteria were allowed to seep into a prepared solution after being vigorously shaken. OTS staff members' toothbrushes and brand new toothbrushes fell victim as well. While waiting for the bacteria to migrate to the solution, each group laid out rows and rows of Petri dishes and Petrifilm (a film used to indicate the presence of a type of bacteria that determines the presence or absence of potentially harmful bacteria like E. Coli) and meticulously labeled and checked for any possible mistakes. My group spent an enormous amount of time preparing for the addition of our samples as we intended on being the fastest group. Maybe not the best scientific method, but it did add some competition and fun to the process! When it came time to add our samples to the Petri dishes and Petrifilm, we had our method down perfectly. I pipetted the samples onto each dish, Anna (the most organized by a long shot) handed me each sample in our predetermined order, Keelin moved the samples around the Petri dish to ensure complete contamination, and Emily covered each Petri dish with a saran-wrap type plastic. It was organized, efficient, fun, and only a tad bit competitive. Twenty-four hours after preparing the samples, we were ready to collect the data. Each of us counted the colonies of the Petri dishes and Petrifilm we plated the day before. Unfortunately, many of our samples were either too concentrated and therefore unable to count or were mixed up in the process of plating the day before. This project happened to be my Faculty Led Project, so my group and I were in charge of presenting the results as well as writing the paper. Our one significant result was the difference between coliform bacteria contaminated toothbrushes between OTS staff and students. OTS staff had over two-thirds contaminated toothbrushes, while we only had two. The most exciting and cool part of the results was that the infected toothbrushes in the student sample group belonged to two students who had been violently ill with a bacterial infection three weeks prior to this experiment. Not going to name any names, but they may or may not have lived together at La Selva, run together every morning, shared a private bathroom, and are in contact much of the day. Not that any groups come to mind or anything.

All in all, the thrill I get from stepping into a lab to start an experiment was only further increased after this project. While challenging at times to understand the data and make sense of no significant results, the rewarding aspect of creating a data set all by ourselves in a forty-eight hour period is pretty unparalleled.

Kat DeRuff