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Flashcards in RTI VII Deck (29):
1

Chlamydophila pneumoniae  are (G+ve/G-ve) and obligate ___

Chlamydophila pneumoniae  are G-ve and obligate intracellular

2

3

describe the phases of Chlamydophila pneumoniae

EB = infectious but metabolically inactive

RB = replicative stage and metabolically active

4

Legionella is (G+ve/G-ve), (motile/nonmotile) and (spore forming/non-spore forming)

Legionella is G-ve, motile and non-spore forming

5

name the 2 clinical syndromes caused by Legionella

  • clinical syndromes:
    • Legionnaire's disease (pneumonia)
    • Pontiac fever (self-limiting)

6

list clinical clues that hint towards Legionnaire's

  • GI/CNS involvement along with resp. disease 

PLUS

  • water source
  • hematuria

7

Legionella is cultured on _____ agar

Legionella is cultured on buffered charcoal yeast extract (BCYE) agar

8

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

9

Legionella pneumophila is facultatively ____ and resides within the _____

Legionella pneumophila is facultatively intracellular and resides within the alveolar macrophages

10

uptake of  Legionalla pneumophila  is via ____ and prevents _____

uptake of  Legionalla pneumophila is via phagocytosis and prevents the fusion of phagosome-lysosome

11

describe what is seen in the image

12

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

13

describe the Sketchy

14

Mycobacterium sp.  grow in ____, are aerobic and non-spore forming

Mycobacterium sp.  grow in long parallel chains (cords), are aerobic and non-spore forming

15

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

16

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

17

describe the cell wall seen

18

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

19

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

20

Mycobacterium tuberculosis survive intracellularly in _____

Mycobacterium tuberculosis survive intracellularly in alveolar macrophages

21

Mycobacterium tuberculosis prevents _____ and inhibits the formation of ______

Mycobacterium tuberculosis prevents oxidative burst and inhibits the formation of phago-lysosome

22

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

23

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

24

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 

25

name the 2 stains used for M. tuberculosis

  • Ziehl-Neelsen stain (AFB)
  • Rhodamine-Auramine Fluorescent stain

26

describe the patient population for which induration >15 mm is a positive result

27

describe the patient population for which induration >10 mm is a positive result

28

describe the patient population for which induration >5 mm is a positive result

29

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