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8 thoughts on “P24 – Johnson”
I really liked your presentation! I was wondering, how can a phage be used to combat bacteria such as Tuberculosis?
The bacteria that we used to isolate our phages from soil, M. smeg, is one of the closest non-pathogenic relatives to the bacteria that causes tuberculosis and that is safe to grow in a lab. Phages, most of the time, kill their bacterial hosts by lysing it after using the host’s ribosomes and proteins to reproduce, and the death rate of bacteria in the area often becomes exponential as the amount of phages released increases. Some phages – primarily lytic phages – are bacteria killing machines. Phages identify their hosts using receptor proteins on their tail fibers and proteins on the bacteria, and phages are host specific. Many phages only infect one host, but others have a wide host range, which means that it can infect and kill a bunch of different bacteria. If we can find phages that have tail protein receptors that can bind to tuberculosis proteins and actually infect the tuberculosis cell, that phage would hijack tuberculosis’s cell machinery to reproduce and then kill/lyse the cell, and the bacterial death in that area would increase exponentially. Thus, the number of bacterial cells causing the infection would decrease or be completely wiped out, treating the infection.
Why wasn’t DNA isolation (and subsequent experiments) performed for this phage? Was there something that prevented you from being able to do this?
Hi! We did perform a DNA isolation for this phage. However multiple gels showed that the DNA isolated was not viable. In the last two weeks of our research, we believe that our lysate was contaminated and it became incredibly dilute (only about 2,400 pfu/mL). We still ran the quality control with DNA isolated with this lysate, but we believe that because the lysate was so incredibly dilute very little DNA was able to be isolated so a small margin of error in our isolation or gel technique could have degraded what little DNA was actually isolated.
Will learning about the existence of this phage make discovering other phages easier? If so, how?
I do not think that learning about the existence of this phage will make discovering other phages easier. Phages are primarily isolated using bacterial hosts. However, I think that if Draw5’s genome was sequenced, using comparative genomics with Draw5’s genome could make determining protein function in other phages genomes much easier. A major task in phage therapy right now is discovering, categorizing, and sequencing as many genomes as possible so that scientists have a large pool to compare their chosen phages too. In lab, we used comparative genomics to determine protein functions in phages with similar genomes, and this process is much more difficult without having genomes with assigned protein functions (that have been tested) to compare your phage genome to.
Why do you believe that Bacteriophages are “criminally under-researched”? It seemed a very strong claim when I heard you say it and I’m curious as to why you believe in this research so strongly.
While I do have a tendency towards drama (on-accident), I think that if phage therapy had been pursued as an antibacterial along side antibiotics, the issue of antibiotic resistance would not be as life threatening as it is now. Bacteriophages were discovered in 1915, and while scientists were not actually able to see what a phage was until much later, they still observed phages antibacterial properties and actually used phages to treat cholera and a few other diseases. However, phage therapy was outshined by the rise of antibiotics. If phage therapy was researched in tandem with antibiotics, there would be less antibiotic resistance over all in my opinion, and we would not be racing to save lives as antibiotic resistant bacterial infections take more and more lives. Most phages on earth are still uncategorized and undiscovered, and I do not think we will actually ever be able to categorize even most of them, but their diversity holds a lot of promise for real-world applications.