Mycobacteria (EXAM III) Flashcards
Mycobacteria is a _______ bacteria genus
Acid fast
Mycobacteria have _____ in the cell wall
Mycolic acid
The mycolic acid in ______ of the mycobacteria make _____ less effective
Cell wall; gram staining
Describe the gram stain of mycobacteria:
Weak gram + staining
What is used instead of gram stain in mycobacteria?
Acid-fast stain or specific fluorescent detection
Discuss the oxygen requirements of mycobacteria:
Obligate aerobe
What two properties of mycobacterium allow them to grow in lung macrophages:
- Facultative intracellular growth
- Obligate aerobes
_____ are the reservoirs for mycobacteria
Humans
The basis for diseases caused by mycobacteria is ______ transmission
Airborne
As few as ____ cells can result in a mycobacterial infection:
10 cells
Mycobacteria was the first in the first organism met in:
Koch’s postulates
Describe acid-fast staining:
Involves driving a stain into the mycolic acid using a hot carbol fuchsin
Basically along the entire surface of bacterial cell wall structure in mycobacteria:
Glycolipids
Glycolipids on the surface of the bacterial cell wall structure in mycobacteria associate with _____ & cause _____
Mycolic acid; causes cord formation (adjacent cells sticking together)
What is the glycolipids covering the surface of the mycobacterial cell wall referred to as?
Cord factor
What is responsible for the virulence of mycobacteria?
Slow, cord-like growth
Cord-like growth of mycobacteria results from:
Adherence of cell surface lipid mycolic acids with glycol-lipids
Why many factors contribute to the virulence contribute to the virulence of mycobacteria, it is mainly resulting from:
The challenge they provide to the immune response
What do we mean when we say infection with mycobacteria “challenges the immune response”?
It obstructs the CD4+ T cell response in macrophages (Delayed-type hypersensitivity response)
A disease like Leprosy or TB is typcially caused by ____ & not _____
The character of the immune response & not the mycobacteria/toxins themselves
How do the mycobacteria facultatively grow intracellularly in alveolar & other macrophages?
Inhibition of phage-lysosome fusion
Involves a cell-mediated response that will result in a granuloma surrounded by lung tissue & inflammatory leukocytes & contains a central area of necrosis where then nuclei have been destroyed
CMI to mycobacterium tuberculosis
A ______ is surrounded by punctuate nuclei of lung tissue & inflammatory leukocytes
TB granuloma
What is at the center of a TB granuloma?
Central area of necrosis where nuclei have been destroyed
Mycobacterium tuberculosis is a “_____” pathogen
Explain:
Life-long; once infected you may be asymptomatic but never cured
What is the transmission of mycobacterium tuberculosis?
Aerosol
Effective ____ is capable of localizing & stopping infection by M. Tuberculosis
Cell-mediated immune response
What is an exception to the idea that an effective cell-mediated response is capable of localizing & stopping infection of M. Tuberculosis?
Young children under 5 years have a high risk for developing progress TB due to insufficient immune system development/activation