Extra Credit: Simon Lax seminar

  1. Summary of the major points of the seminar
  2. Reflections on the seminar. This should include your thoughts about it, any critical comments, discussion of at least one way it connects to things you’ve learned in BIOL 342 class, and at least one question that you have about microbiological aspects of the seminar.


Simon’s presentation was divided into three main sections. First, he gave us some background information for his studies and stated why studying microbiomes was important. He then talked about his first study where he mapped microbial communities in the home. The seven homes he sampled had a range of people living there and some had pets. They sampled the hands, feet, and noses and compared them to surfaces around the home such as door knobs and counter tops. He found that the microbial communities of each house matched their occupants. Each person has their own microbial fingerprint that seems to be left in the home. Doorknobs matched the microbes found on hands while the bedroom floor matched samples from the feet. When a person leaves, their microbial fingerprint begins to decline over the next few days. He was trying to answer questions such as: Do the microbial communities of home surfaces match their occupants; how unique are microbiomes in homes; what are the major interactions between people and their homes; and how stable are microbiomes on home surfaces? Lastly, he went over his study of microbial development in the hospital from pre-opening to patient care. There was a complete change in the microbiome between pre-opening and patient care. Completely new microbial communities were found as more people frequented the areas being tested. There were no real trends found in the distribution of microbial communities. Especially on the floor, there was a homogenous effect, possibly because people walked everywhere. Objects in the hospital that were often in contact had similar results. This included nurses with their pagers and phones, and patients with the handrails on their beds. An interesting result he found was that antibiotics had no real effect on biota on the skin with the exception of topical creams such as neosporin. The results of both of his studies were based on the 16s method using amplicon sequencing.

I thought his presentation was really interesting and I’m really glad I went to it. I didn’t understand the entire thing, but I’m pretty sure I was able to understand most of it because of the classes I’ve taken for biology so far. The results that he found seemed to be in line with most of his predictions and they made sense to me as well. By creating these maps of how microbiomes move, we can track disease and be able to predict how the biomes will change over time. It sounded like most of his experiment came from swabbing the samples, just like we have done with our microbe project. By learning how to do this in class, I was able to understand how he went from taking samples to turning them into data to answer the questions he posed. But even with the results he found, there could still be hundreds more species that were not able to grow in culture. One question I have is: Would outdoor pets versus indoor pets have a differing spread of microbial communities throughout the home? The house with 3 dogs appeared to have a more diverse and spread out microbiome. How much more would an outdoor pet diversify the microbes found?