mycobacteria Flashcards
1
Q
characteristics of mycobacteria
A
slow growing (divide once q 24 hrs)
hard to grow in culture
mycolic acid in cell envelope → acid-fast stain (stain not removed by acidified alcohol)
airborne transmission: need negative pressure rooms + N95 masks for protection
2
Q
positive PPD test demonstrates
A
active of latent TB infection
history of BCG vaccine
infection with nontuberculous mycobacterium
3
Q
negative PPD test demonstrates
A
TN: no TB but may have conditions that resemble TB (sarcoidisis, nontuberculous mycobacteria)
FN: immunosuppresive meds (steroids), immunocompromised host (elderly, cancer, HIV)
