STEP 1 Gram Positive Bacteria 3 Flashcards

1
Q
Streptococcus agalactiae (GBS)
gram, shape, catalase, coagulase, *hemolysis, resistance (differs from GAS)
A

Gram positive cocci
Catalase and coagulase negative
B-hemolysis
Bacitracin resistant

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2
Q

GBS colonizes (1)

A

GBS colonizes vagina

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3
Q

GBS diseases (3)? Which population primarily (think of its colonization location)?

A

Pneumonia, meningitis, and sepsis

Mainly in babies

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4
Q

GBS and pregnancy…screening and prophylaxis

A

Screen pregnant women at 35-37 weeks.

+ culture patients receive intrapartum PCN prophylaxis

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5
Q

Two main Enterococci bacteria

A

Enterococcus faecalis

Enterococcus faecium

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6
Q

Enterococci (group D strep) features

  1. location
  2. resistance
  3. infection causes (3)
A
  1. Normal colonic flora
  2. Penicillin G resistant
  3. Cause UTI, biliary tract infections, and subacute endocarditis
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7
Q

Streptococcus bovis (non-enterococcus strep):

  1. Colonizing location
  2. Causes which infections (2) in which patient population (1)
A
  1. Colonizes the gut

2. Causes bacteremia and subacute endocarditis in colon cancer patients

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8
Q

Enterococcus algorithm findings:
Gram and shape
hemolysis
growth in which medium (2)

A

Gram + cocci
Catalase -
Gamma hemolysis
Growth in bile and 6.5% NaCl

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9
Q
Non-enterococcus algorithm findings:
gram stain and shape
catalase
hemolysis
growth medium (compare to entercoccus)
A

Gram + cocci
Catalase -
Gamma hemolysis
Growth in bile, NOT in NaCl

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10
Q

Corynebacterium diphtheriae algorithm findings

A

Gram + BACILLI (ROD)

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11
Q

C. diphtheriae causes diphtheria via _____ encoded by _____

A

Causes diptheria via EXOTOXIN encoded by B-prophage

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12
Q

C. diphtheriae exotoxin inhibits ______ via _____ of _____

A

Inhibits PROTEIN SYNTHESIS via ADP-ribophosphorylation of EF-2

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13
Q

Symptoms of diphtheria (4)

A
  1. PSEUDOMEMBRANOUS PHARYNGITIS (gray-white plaques/membrane)
  2. lymphadenopathy
  3. myocarditis
  4. arrhythmias
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14
Q

Lab diagnosis of diphtheria (3)

A
  1. Algorithm findings
  2. Elek test for toxin
  3. Grows black colonies on cystine-tellurite
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15
Q

What kind of vaccine is the diphtheria vaccine?

A

Toxoid vaccine

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16
Q

ABCDEFG of diphtheria

A
ADP-ribophosphorylation
B-prophage
Corynebacterium
Diphtheriae
Elongation Factor 2
Granules
17
Q

Spore-forming gram + bacteria found in soil (3)

Other spore formers (3)

A

Bacillus anthracis
Clostridium perfringens
C. tetani

B. cereus
C. botulinum
Coxiella burnetii

18
Q

Lab algorithm findings of clostridia

A

Gram +
Spore-forming
Obligate anaerobic Bacilli

19
Q

C. tetani produces ______, an exotoxin causing _____

A

C tetani causes TETANOSPASMIN, an exotoxin causing tetanu

20
Q

How do the tetanus and botulinum toxins cause damage?

A

Both toxins are proteases that cleave releasing proteins for neurotransmitters

21
Q

Which neurotransmitters does tetanus block? Which cells do the NTs come from?

A

GABA and glycine (both are inhibitory NTs)

Renshaw cells in spinal cord

22
Q

Symptoms of tetanus (3)

A

Spastic paralysis
trismus (lockjaw)
risus sardonicus (grinning expression causes by spams of facial muscles)

23
Q

How does C. botulinum cause damage?

A

Produces a preformed, heat-labile toxin that inhibits ACh release at the NMJ causing botulism

24
Q

How do adults acquire botulism? Babies? which food is associated with babies and botulism

A

In adults, the disease is caused by ingestion of preformed TOXIN.
In babies, ingestion of SPORES in HONEY causes disease (floppy baby syndrome)

25
How does C. perfringens cause damage? Produces which toxin? symptoms (2)
Produces ALPHA toxin that causes MYCONECROSIS and HEMOLYSIS
26
What is the pathogenesis of the two C. diff toxins?
Toxin A, ENTEROTOXIN, binds to the brush border of the gut | Toxin B, CYTOTOXIN, causes cytoskeletal disruption via actin depolymerization--> pseudomembranous colitis --> diarrhea
27
Use of which antibiotics (2) is associated with C. diff diarrhea?
Ampicillin and clindamycin
28
How is C. diff detected?
Look for the toxins
29
Treatment for C. diff (2)
Metronidazole or oral vancomycin
30
Clostridium perfringens: | Name of the produced toxin? What is the cellular mechanism of this toxin
Produces ALPHA toxin ("lecithinase") | It's a phospholipase that cleaves the phospholipid bilayer of cells