Microbiology: Viral Pathogenesis Flashcards
A 25 year old female presents to your clinic with cervical cancer. She tested positive for HPV. How did this particular virus cause her condition?
HPV binds to RB, keeping it activated and p53, deactivating it. This pushes cells into the S phase and cells divide.
A patient presents with shingles. What is happening in his neurons?
Shingles is caused by a herpes virus that lies dormant in neurons. It has all of the DNA replication machinery necessary to replicate and flare-ups occur when it begins to replicate.
A first year medical student makes a rookie mistake when looking at viral replication. He sees a lack of activity and calls it the incubation period. What is this really?
Eclipse period. This is the time DNA is being replicated.
Why is polio virus more infectious than its counterpart RNA viruses?
Polio is a +RNA, which means it can be translated directly into proteins. Its counterpart, -RNA, need RNA-dependent RNA polymerase to make it into a +RNA before it can be translated into proteins.
What PAMPs are created during viral replication that allows our innate immune system to recognize them?
Double-stranded RNA (TLR 3,7,8), un-capped RNA (RIG), unmethylated DNA (TLR 9) and cytosolic DNA.
You suspect a viral infection in a patient, but want to be sure. What properties of enveloped viruses could you exploit to test for a viral infection?
Syncytia formation (pH independent fusion of cells mediated by surface glycoproteins) and Hemagglutination (pH dependent agglutination of RBCs mediated by glycoprotiens)
Viruses are kind of like X-men. They can do two things to avoid the human immune system. How do they do this?
Antigenic shift (human genes reasserted so a virus can now affect humans) and antigenic drift (random mutations due to RNA-dependent RNA polymerase transcription errors)
Why can you get immunized after being bit by a rabid dog?
Rabies has a very long incubation period. You can develop immunity before it replicates and spreads to cause major damage.
How does HIV turn into AIDS?
Continual depletion of CD4 T cells ultimately results in decreased CD8 activity. Once this happens, the virus can replicate uncontrolled and kills the host.
At Nexus, how would procedures differ between a patient suffering nerve pain from latent chickenpox infection and a patient suffering from latent HSV1 infection?
Chickenpox = DRG HSV1 = Trigeminal ganglia
What is HIV tropic for?
CD4 CCR5 receptors
Why do people with herpes get gross things on their lips?
The virus causes cell lysis
Major vaccinations
Polio, MMR, VZV, HAV, HBV, HPV, influenza, rabies and rotovirus
Would poxvirus or herpes virus be more infectious?
Poxvirus: it has DNA replication AND RNA transcription where herpes only has genes for DNA replication
A pregnant patient presents to the hospital experiencing arthralgia and aplastic crises. What is the likely infectious agent? How could this affect her child?
Parvovirus. Hydrops fetalis.
