exam 5 - TB Flashcards
(31 cards)
what organism causes TB
mycobacterium tuberculosis
describe the staining of TB
acid fast
neither GP or GN
cannot be decolorized
how is isoniazid activated
Kat G protein
moa isoniazid
forms adducts w/ NAD+ and NADP+ then inhibits enzymes that use them and inhibits InhA
resistance of isoniazid
overexpression of InhA
what is the most effective TB
rifampin; high sterilizing activity
moa rifampin
binds to RNA polymerase and blocks elongation
what has synergism w/ rifampin
ethambutol
moa ethambutol
inhibits mycobacterial arabinosyl transferase (disrupts cell wall)
resistance ethambutol
overexpression of mutations in arabinosyl transferase
what drug shortened TB treatment and by how long
pyrazinamide; shortened by 6 months
activation of pyrazinamide
low pH and pncA enzyme
moa pyrazinamide
inhibition of panD –> inhibits coenzyme A synthesis
resistance of pyrazinamide
primarily due to mutation in pncA
what can replace ethambutol
moxifloxacin
moa moxifloxacin
traps gyrase on DNA and disrupts replication
what kind of killer is bedaquiline
bactericidal
moa bedaquiline
inhibits ATP synthase
resistance to bedaquiline
mutations in atpE
activation of Pretomanid
Ddn
moa pretomanid (aerobic)
forms metabolite that inhibits mycolic acid production
moa pretomanid (anaerobic)
generates reactive oxygen series such as NO
what are the two TB regimens
RIPE
BPaL
what are the stages of TB
latent, subclinical, active
