1. Microbiota increase pathogenesis by promoting intestinal infection of enteric viruses; specifically, poliovirus was used as a model in this paper.

2. The PVRtg-Ifnar1-/- mouse is a transgenic mouse that has been made susceptible to oral infection by poliovirus. The first aspect of the transgenic mouse is that human poliovirus receptor was introduced to allow for infection. Humans are the only known hosts for poliovirus so mice were engineered to allow them to be infected. However, this alone was not sufficient for oral infection. To make a proper model since most poliovirus infections are fecal-oral, the mice were made immunodeficient by knocking out interferon-α/β receptor. This mouse was used in the experiment to serve as a model for human poliovirus …show more content…
These findings support the data in Figure 4C, extending that not only bacteria promote it, but the level of population affects pathogenesis.

7. a. The purpose of the experiment in Figure 4G is to see if the virus binds to LPS.
b. Viral titer (PFU), is the measurement of the amount of virus, was measured.
c. The control used was poliovirus without biotin-LPS added. It was useful to determine if LPS is binding to the virus.
d. After the PBS washes, the unbound virus was washed off. But the virus that had LPS remained bound to biotin-LPS was not eluded.
e. Poliovirus binds LPS.

8. a. The purpose of the experiment in Figure 4H is to measure if poliovirus was able to associate with Bacillus cereus.
b. Cell associated radioactivity was measured and quantified as percent cell-associated virus. Radiolabeled poliovirus was incubated with PBS, which served as a negative control, or with Bcillus cereus for one hour. Then afterwards, either PBS or B. cereus was added and incubated with HeLA cells (in vitro). They measured cell associated radioactivity which was used to quantify cell-associated virus. They measured how much radioactivity was associated with the cells as a representative measure of the