3.2.2 Bacillus, Listeria and Corynebacterium Flashcards Preview

Infectious Disease > 3.2.2 Bacillus, Listeria and Corynebacterium > Flashcards

Flashcards in 3.2.2 Bacillus, Listeria and Corynebacterium Deck (42)
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1

What allows bacillus organisms to survive in the environment?

Spore-forming

2

What's wrong with Bob?

Bob has Bacillus anthrasis

3

What are the symptoms associated with inhalational anthrax? What is the associated mortality rate?

4

What is one of the key features of inhalational anthrax seen on imaging?

Mediastinal widening

5

What are the two forms of GI anthrax?

Oropharyngeal: local ulceration leading to regional lymphadenopathy (tonsilitis), edema and fever

Intestinal: ulcer w/ initial symptoms of fever, nausea, vomiting, malaise, followed by bloody diarrhea or sepsis

6

What is the key feature of cutaneous anthrax?

Painless pauple develops into a black necrotic ulcer (eschar) with edema

7

What is the pathogenesis of bacillus?

8

What is the unique feature of the antiphagocytic capsule of bacillus?

Poly-D-glutamic acid

9

What are the two active subunits of the A3-B7 anthrax exotoxin?

Edema (EF): activates adenylate cyclase -> increased cAMP

Lethal factor (LF): inactivates MAP-kinase-kihase -> results in necrosis

10

Draw a diagram of the bacillus A-B toxin pathogeneis.

11

After a presumptive diagnosis of Bacillus is made, what confirmatory labs are conducted by the CDC?

12

What is the DOC for Bacillus anthrasis?

Ciprofloxacin

13

What preventive measure can be enacted if a patient is at risk for inhalation anthrax?

60 days of antibiotic prophylaxis

14

What human mAb targets PA of Bacillus anthrasis?

Raxibacumab

15

What are some of the defining characterstics of Bacillus cereus?

Gram pos, spore-forming, facultative anaerobe, motile, beta-hemolytic on SBA, ubiquitous in soil

16

What causes the emetic form of GI dz caused by Bacillus cereus?

Heat-stable enterotoxin

17

What causes the diarrheal form of GI dz caused by Bacillus cereus?

Heat-labile toxin

18

What type of eye pathogy is associated with Bacillus cereus?

19

What is the DOC for Bacillus cereus?

Vancomycin or Clindamycin

Proper refrigeration of food

20

What diagnostic tests can help lock down a diagnosis of Bacillus cereus?

Contaminated food or infected patient specimen (eye, IV, site, etc)

Generally no fecal samples

21

What are the general characteristics of Listeria?

22

What type of hemolysis is Listeria?

Weak beta-hemolytic: zone of lysis is narrow

23

What unique about Listeria and its growth?

Grows at 4 degrees Celcius, refrigeration of food is not sufficient

24

What subgroup of the population is at most risk for a Listeria infection?

Pregnant Women (risk increased 20-fold)

25

What are some characteristics of Early-onset Listeria dz?

Transplacentally acquired

Granulomatosis infanticeptica: disseminated abscesses and granuloma in multiple organs

80% mortality rate

26

What are some characteristics of Late-onset Listeria dz?

Acquired at birth or soon thereafter

Meningoencephalitis, septicemia

70% mortality rate

27

What are some of the dz's caused by Listeria in immunocompromised pts?

Meningitis, bacteremia, 50% fatality rate in severely immunocompromised pts and infants

28

Where do Listeria infections typically initiate?

Enterocytes or M cells in Peyer's patches

29

What type of immunity is essential for clearing a Listeria infection?

Cell-mediated immunity

30

What are the 4 main virulence factors of Listeria?

Internalins (Inl): forced phagocytosis

Listeriolysin O (LLO): pore-forming hemolysin

2 Phospholipases (PI-PLC, PC-PLC)

Actin-binding protein (ActA): Mediates actin polymerization