Systemic Infection Flashcards
What is Trichinella?
Helminth parasite naturally occurring in rats, which infects pigs and humans
What are the two stages of Trichinella infection?
Enteral (localised to GI tract) and parenteral (infects other organs, e.g. muscle)
What makes up the mucous layers?
Secreted mucins and transmembrane proteins (non-secreted mucins) that make up the inner mucus layer).
What happens once a pathogen interacts with transmembrane mucins?
Stimulated mucous secretion
Mucin granules expand on hydration and surround pathogen with mucous containing antimicrobials
Mucin is shed from the cell
How can pathogens overcome the mucous barrier?
Flagella-mediated motility
Enter via M cells in microfolds of GI tract which do not have mucous.
Toxin secretion (disrupt tight junction, block epithelial cell growth, block mucous secretion)
Use cilia and mucous movement to spread
Which branch of the immune system is important for systemic infection?
Adaptive
Which branch of the immune system is important for local, surface infection?
Innate
Why can mycobacterium leprae only cause leprosy at extremities?
Its activity is temperature-dependent.
What is the site of measles virus replication?
Lymph
What family of viruses does measles belong to?
Paramyxovirus
Is measles a DNA or RNA virus?
RNA
Is measles -ve strand or +ve strand?
-ssRNA
What two cell types does measles infect first?
Dendritic and macrophages
In what cells does measles first replicate?
Lymphocytes
Following replication in lymphocytes, what tissues does measles infect, in order?
Respiratory tract, mucosa, skin.
What is the R0 of measles?
15-20
What makes measles susceptible to vaccination?
It infects the naive population
What bacteria causes syphilis?
Treponema pallidum
What are the four stages of syphilis?
Primary, secondary, latent and tertiary
Describe the primary stage of syphilis.
Chancre at site of infection. Persists 3-6 weeks.
Describe the secondary stage of syphilis.
4-10 weeks after initial infection. Infection of macrophages and spread to various parts of the body Resolve after 3-6 weeks 25% recurrence Lesions at extremities Systemic
How does Treponema pallidum avoid the immune system in the latent stage of syphilis?
Lipid-rich surface
Are people with tertiary syphilis infectious?
No
What is syphilis treated with?
Penicillin or doxycyclin if allergic to syphilis
Why was syphilis treated with malaria?
The fever (41 degrees) killed syphilis bacteria
