10 thoughts on “P44 – Ngo

    1. How does the phage showing up on the plate indicate that it might be a potential TB treatment? just a little unclear in the presentation

      1. Good question! The plate was coated with M. smeg bacteria whose structures and functions are closely related to the pathogenic bacteria causing TB. Clear plaques showing up on the plate indicates that the phage was able to infect and lyse the M. smeg bacteria. From this, our hypothesis is that the phage has the potential to infect and lyse the TB bacteria as well. And if the phage can lyse TB bacteria, if it is proven safe in vivo, the phage can potentially be used to lyse TB bacteria, treating patients infected with TB.

    2. Good question! Clear plaques show that the phage only undergoes lytic cycle (lysis upon infection) without lysogenic cycle (phage passively replicates along with the bacterial host, and may undergo lysis later). Therefore, clear plaques indicates lytic phages.

      The other type of phage is temperate phage which undergoes lysogenic cycle and may undergo lytic cycle. This temperate phage will show turbid plaques (bull-eye plaques).

    1. Clusters A and K have a variety of subclusters (A1 to A10, K1 to K5). In this class with the limited timeline, we were only able to perform PCR to rule out A3, A4, K1, K3 (Figure 4). Each PCR cluster sample consisted of 2 µl of phage DNA/22.5 µl PCR reaction mix/2 µl of cluster primer mix. I apologized I don’t fully know if you are asking about the figure or the methods. Please let me know if you have further questions!

    1. Good question! The soil sample was collected at the location coordinates 40.002890N/105.262490W in Boulder, Colorado on January 24, 2022. The sample, which was cold and moist upon collection at 5°C, was taken near Kitt Ponds around some bushes and under a very thin layer of mulch. I would say it is an accessible location to recollect a similar soil sample (maybe better during winter to meet the temperature).

    1. Good question! This was not discussed in the presentation. According to the studies reported by Abedon & Yin (2009) and Gallet et al. (2011), the phage showing small plaque size of 1-2mm in diameter is predicted to have low adsorption rate and lysis rate.

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