Extra Credit Simon Lax Seminar Response

1.  The talk began with Lax presenting the idea that microorganisms shape our lives through the environment that we live in. Now that we spend much of our lives in fabricated environments (our houses, schools, workplaces) our relationship with microbes has changed. Simon Lax described two projects that set out to describe the interactions between the microbes in our built environments and the microbes on our skin. First, Lax introduced the Home Microbiome Study, undertaken to understand the relationship of microbes found on an individuals skin and the microbes found in their house. There were some interesting conclusions from this project – including the suggestion of a microbial “fingerprint’. The results provided evidence of being able to identify an individual’s environment from their skin (or an environment from an individual). Lax then talked about colonization and persistence of microbial communities in new hospitals. The succinct results showed that there was an entirely different microbial community in the hospital pre-opening and post-opening. Also, the most notable interactions of environment and individuals were between what you would suspect to be highly correlated- for example, a nurse and her phone. The talk finished with a brief look into the clinical results of the hospital study such as the concerns around antibiotics and other factors that influences skin microbiomes.

2.    I enjoyed this lecture and though that the presentation was both informative and captivating. Additionally, the topics Lax is researching are very relevant. I found myself wanting to know more about the results of both studies that Lax described. Specifically, I began to question- as someone in the audience queried- what kind of surfaces are most accommodating to, bacterial growth? For example, will hardwood floor or carpet be more conducive to a diverse micro biome? And how would a different floor material impact the exchange of bacteria from us to our built environments. I was also curious about some of the factors in the hospital study that influenced how similar surfaces in one area would be. Lax said that larger surface similarities are found when the temperature is colder and humidity is higher. I thought those results were interesting and I would like to know more about these factors and why they impact the similarities in the way they do.

When we discussed the history of microbiology in class we talked about the scientific developments that were made as reactions towards the isolation and discovery of microorganisms. A lot of those, such as microscopes or Koch’s postulates, were made to understand and explore what microorganisms are and what they do. The research that Simon Lax is involved in is also reactionary in this way. Humans have transitioned to a lifestyle that is spent primarily inside our built environments and this has influenced our relationship with microorganisms. The quest to understand what that change is and how it will affect humans mirrors the way that history was propelled by the fundamental question about what a microorganism is.

ExtraCredit: Simon Lax seminar

Simon Lax presented the lecture “Our Microbial Interaction with Build Environments” where he described his research projects. Simon emphasized the importance of understanding on how microorganisms in the environment can affect us by changing our microbiota and, thus, affect our immunological health. In his research project, multiple environmental samples were collected (with cotton swabs) in order to extract genomic DNA, amplify the gene of interest via PCR, and sequence formed amplicon. 16S rRNA (for bacteria and Archaea) and 18S (for Fungi) amplicon sequencing methods were used to study taxonomy of collected samples. Simon added that his preliminary research has been completed and a Shotgun metagenomic sequencing would be applied as the next step.

In his research, Simon was answering the following questions: Do the microbial communities of home surfaces similar to those on home occupants; how unique the microbial communities are in different homes; what are the major interactions between the home environment and the occupants; how stable the microbial communities on home surfaces. There were samples collected from six home surfaces (counters, floors, doorknobs), three from humans (hands, feet, and noses), also from pets (feet). 18 participants and 7 homes were participating in the experiment (I didn’t catch on how many pets were participating). From the presented results, the person can be tracked in his/her movement in the house via “source-tracking model” because each one of us has “unique microbial fingerprint” (Lax, 2016). For example, “68% of microorganisms on the bathroom door know were originated from the hand #1”, and “much less transfers from noses” (per Simon Lax, 2016). When the occupant leaves the house for several days, microbial fingerprints on home surfaces decline. If to introduce pets to the data, it “mixes everything up because pets are literally everywhere” (Simon Lax).

Simon also spoke about his other research projects: “Forensic insight from Shoe and Cell phone” and “Colonization and Succession of Hospital-Associated Microbiota”. In the results, the person can be matched with the places he/she was walking. As hospitals are dealing with MRSA, different samples from patients’ rooms, floors, and nurse stations were collected for research purposes. The following “hot spots” were found, such as door knobs, handrails, nurses’ pagers and phones, and floors.

In the conclusion, we live in a diverse microbial environment, some of it is a part of us. In the Microbiology class this semester, students will be completing the similar projects: collecting samples from different environments, extracting DNA, and analyze bacterium’s genome sequence with its following identification. Students will present their projects as Simon did (less audience, of course). The lecture was very informative and interesting. The question I had was the following: if the hospitals can benefit with implementation of floor disinfecting barriers? Can disinfecting barriers on the hospital floor reduce the diversity and abundance of microorganisms? It can be very important especially if the patient has a compromised immune system response and unnecessary exposure to microorganisms can harm but not benefit the patient.

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?

Extra Credit: Simon Lax seminar (Feb. 10, 3 pm)


For extra credit, you can either attend or watch online later a special seminar by guest speaker Simon Lax.  

Seminar time and place: Friday, Feb. 10, 3-4 pm, Murie Auditorium

The seminar recording will be available  here  within a week following the seminar.

Deadline: Feb. 24

For 5 pts extra credit:

Write a 2-paragraph website post addressing the following items.

Be sure to categorize your post as “ExtraCredit” Simon Lax”

  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.