Lecture 32 - Lower Respiratory Tract Infections Flashcards
What are the unique features of the mycoplasmal cell envelope?
no cell walls, they use sterol compound from host
Mycoplasmal infections cause …
Mild pneumonia
Binds to base of cilia, compromise ciliary escalator
Why is the incidence of pertussis in the US currently icnreasing?
The vaccine we use is poor, people do not get boosters, some adults may be asymptomatic and spread it
What causes the symptoms of pertussis?
Bordetella pertussis toxin (AB5)
a. A part ADP-ribosylates an inhibitor of cAMP synthesis
b. overproduction of cAMP
c. leads to excess mucus
d. cough
Why did the US switch from DPT to DTaP?
DTaP has fewer side effect, uses fragments
DPT used the whole organism which contained LPS
Infection of Mycobacterium tuberculosis can lead to what?
exudative lesion which becomes a granuloma
What may happen in non-granulomatous TB infections?
it can heal or necrotize the lung
How is TB treat, prevented, and detected in a person?
Prevented with BCG vaccine
Detect by injecting inactivated bacteria
TB is treated with chemotherapy with multiple drugs
What might make a better TB vaccine?
adding a phospholipase gene
What are the roles of hemagglutinin and neuraminidase proteins in influenza infection.
H allows binding
N allows release of virus
Antigen drift
Mutations in RNA alters the spike protein. Immune system won’t recognize altered spike proteins.
Antigenic shift
multiple strains infect an alternate host, new virus is assembled using parts from each strain.
Name 3 major pandemics of influenza in the last 100 years
H1N1: 1918 “Spanish” Flu
H2N2: 1957 “Asian” Flu
H3N2: 1968 “Hong Kong” Flu
How do we treat and prevent influenza?
Treated with amantadine and oseltamivir
Prevent with annual vaccine prepared in embryonated chicken eggs
How and why is the flu vaccine altered every year? Why might a newly-discovered change this?
to match the expected new strains
potential for “broadly neutralizing” antibodies that bind HA
