Lec 6-4 - Mycobacteria/Nocardia Flashcards
look at old questions
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long chain fatty acids and is much of organisms genetic info for synthesis and substitution of these lipids
mycolic acids
Mycobacterium tuberculosis replicates blank compared to other clinically important bacteria
slowly
generation time for tuberculosis
15-20 hours
stain for tuberculosis
ziehl nielson
organism resists decolorization by blank so it is considered acid fast
acid alcohol
shape of tuberculosis
bacillus
mycolic acid is in this part of a cell and the chains are longer in tuberculosis than nocarda/corynebacteria
cell wall
special media for growing mycobacteria but growing is slow
lowenstein jensen agar
ppd stands for
purified protein derivative test
people infected with tuberculosis but dont have the disease cannot blank
spread the infection (called latent tb infection)
it may take this many weeks for the infected person to develop a positive reaction to the test
2-10 weeks
percent of people infected with tb will develop the disease within the first 1-2 years after infection
5 %
percent of people that will develop tb disease after infection sometime after those 2 years
5% (10% total)
the latent tb infection is proven with the blank
chest x ray
enzyme product of the gene katG in isoniazid. if mycobacterium doesnt have this enzyme then it will be resistant to isoniazid
catalase/peroxidase
chemotherapy of tb
isoniazid… sometimes rifampin
isoniazid mechanism of action
inhibit synthesis of mycolic acid in cell wall
two things that can be affected by isoniazid
liver (hepatitis), neurotoxicity (dont drink alcohol)
rifampin mechanism of action
inhibit dna dependent rnap of mycobacterial cells
cause of leprosy
mycobacteria leprae
leprosy has skin lesions, hypoesthesia and blank
peripheral neuropathy
risk of nocardia is associated with deficient blank immunity
cell mediated (aids, lymphoma, transplantation)
most common problem with nocardia
respiratory diseases like cough, fever
nocardia is diagnosed by branching blank that is acid fast on a modified acid fast stain because there is like half the amount of mycolic acid
branching gram positive hyphae
nocardia is treated by blank
sulfonamides
