RTI VII Flashcards
Chlamydophila pneumoniae are (G+ve/G-ve) and obligate ___
Chlamydophila pneumoniae are G-ve and obligate intracellular
describe the phases of Chlamydophila pneumoniae
EB = infectious but metabolically inactive
RB = replicative stage and metabolically active
Legionella is (G+ve/G-ve), (motile/nonmotile) and (spore forming/non-spore forming)
Legionella is G-ve, motile and non-spore forming
name the 2 clinical syndromes caused by Legionella
- clinical syndromes:
- Legionnaire’s disease (pneumonia)
- Pontiac fever (self-limiting)
list clinical clues that hint towards Legionnaire’s
- GI/CNS involvement along with resp. disease
PLUS
- water source
- hematuria
Legionella is cultured on _____ agar
Legionella is cultured on buffered charcoal yeast extract (BCYE) agar
describe the pathogenesis of Legionella pneumophila
- exposure = inhalation of contaminated aerosols
- facultatively intracellular (alveolar macrophages)
- uptake is via phagocytosis; prevent fusion of phagosome-lysosome so resists degradation
- much of damage is due to host inflammatory response
Legionella pneumophila is facultatively ____ and resides within the _____
Legionella pneumophila is facultatively intracellular and resides within the alveolar macrophages
uptake of Legionalla pneumophila is via ____ and prevents _____
uptake of Legionalla pneumophila is via phagocytosis and prevents the fusion of phagosome-lysosome
describe what is seen in the image
the most commonly used lab test for diagnosis of Legionnaire’s disease is _____
if ____ is negative but Legionnaire’s disease is still suspected, then a _____ is required
the most commonly used lab test for diagnosis of Legionnaire’s disease is urinary antigen test
if urinary antigen test is negative but Legionnaire’s disease is still suspected, then a respiratory culture is required
describe the Sketchy
Mycobacterium sp. grow in ____, are aerobic and non-spore forming
Mycobacterium sp. grow in long parallel chains (cords), are aerobic and non-spore forming
Mycobacterium sp. grow in long parallel chains (cords), are (aerobic/anaerobic) and non-spore forming
Mycobacterium sp. grow in long parallel chains (cords), are aerobic and non-spore forming
Mycobacterium sp. grow in long parallel chains (cords), are aerobic and (spore-forming/non-spore forming)
Mycobacterium sp. grow in long parallel chains (cords), are aerobic and non-spore forming
describe the cell wall seen
resistance to TB is largely dependent on subset of ____ that produce _____
resistance to TB is largely dependent on subset of CD4+ helper T cells that produce α-interferon
list the mechanisms of pathogenesis of Mycobacterium tuberculosis
- mechanisms:
- prevents oxidative burst and inhibit phagosome-lysosome fusion
- role of sulfolipids (part of mycolic acid)
- resist lysosomal enzymes, reactive oxygen species
- cell wall lipids, LAM, secretion of SOD (to resist ROS secreted by the host cells)
- escape phagosome → cytoplasm
Mycobacterium tuberculosis survive intracellularly in _____
Mycobacterium tuberculosis survive intracellularly in alveolar macrophages
Mycobacterium tuberculosis prevents _____ and inhibits the formation of ______
Mycobacterium tuberculosis prevents oxidative burst and inhibits the formation of phago-lysosome
Mycobacterium tuberculosis resists ____ enzymes and generates ____ to resist reactive oxygen species
Mycobacterium tuberculosis resists lysosomal enzymes and generates superoxide dismutase (SOD) to resist reactive oxygen species
Mycobacterium tuberculosis secrete ____ such as exochelins which have a very high affinity for _____
Mycobacterium tuberculosis secrete siderophores such as exochelins which have a very high affinity for ferric ions
describe the culture and diagnosis of M. tuberculosis
- laboratory isolation = necessary for diagnosis and to enable determination of antibiotic sensitivity
- culture: require enriched or special medium
- Lowenstein-Jensen agar
- Oleic acid - albumin broth
- antimicrobial susceptibility testing = increasingly important
name the 2 stains used for M. tuberculosis
- Ziehl-Neelsen stain (AFB)
- Rhodamine-Auramine Fluorescent stain
describe the patient population for which induration >15 mm is a positive result
describe the patient population for which induration >10 mm is a positive result
describe the patient population for which induration >5 mm is a positive result
prevention of TB is via the ___ vaccine which is an attenuated ____ strain
prevention of TB is via the Bacillus Calmette-Guerin (BCG) vaccine which is an attenuated M. bovis strain
