Week 1: A Crash Course in Bacterial Genetics

I am taking a bit of an unconventional path to NYC that first involves a three week stop in Long Island. I am currently participating in an Advanced Bacterial Genetics course at Cold Spring Harbor Laboratory. The course is a mixture of lectures, wet labs, and analysis. We are ambitiously undertaking eleven separate genetics experiments in four different organisms. It’s an intense crash course in genetics, and I hope what I learn in this course will directly translate to my clinical project when I arrive in NYC and my research when I return to Cornell.

This is the end of my second week at the course. I’ll admit, at first it was really overwhelming. Except for me, everyone here has a background in microbiology. Both conceptually and experimentally, I had a lot to catch up on. I used more pipettes in my first two days than I have in the rest of my life. However, the instructors and my course-mates have been so patient and helpful with all of my microbiology questions. Now I am starting to feel a bit more comfortable, and it’s exciting to imagine how I can use some of the tools and techniques I am learning on my clinical project once I arrive at the Hospital for Special Surgery. It has also been so interesting to hear learn about what the microbiology community and the biomedical engineering community have in common and what is different, and I think there is a lot of room for interesting interdisciplinary work.

A third of our experiments focus on genetic mutations in Staphylococcus aureus. One serious form of staph infection is on joint replacements. Although infected joint replacements only happen in a small percentage of patients, they take a big toll. Patients with infected joints may require a revision, and the stress of another major surgery should be avoided.

Studying how staph acquires antibiotic resistance genes could help decrease infections; however, studying staph genetics can be tricky. It is much harder to genetically manipulate S. aureus than it is to manipulate a model organism like E. coli. Bacteria can acquire changes in their genome through random mutations or through the introduction of a new piece of DNA from an outside source. The willingness of a bacterium to accept DNA from outsides sources is referred to as competency. This week I learned some techniques to increase competency in S. aureus by using E. coli as a type of “middle man”. I could possibly use some of these techniques to study what strains of S. aureus are more likely to grow on orthopaedic implants, and if disrupting certain genes could decrease survival on a implant. The lab that I will be joining this summer has a implant infection model in mice, and I am excited that I am gaining experience with bacteria. Hopefully I can hit the ground running as soon as I get there.   

Figure 1. One of my plates of S. aureus.