Block 2: Recall Q's - Gram-Negative G.I. Tract Rods

Question 1

Gram-negative bacillus, oxidase negative, lactose-fermenting pink colonies, most common cause of urinary tract infections

Answer 1

E. Coli

Question 2

Gram-negative bacillus, oxidase negative, white/colourless colonies on MacConkey agar, motile, produces H₂S, black colonies on Salmonella-Shigella agar

Answer 2

Salmonella

Question 3

Gram-negative bacillus, oxidase negative, pink mucoid colonies on MacConkey agar, pneumonia in alcoholics/health-care associated pneumonia

Answer 3

Klebsiella

Question 4

Gram-negative curved bacillus, oxidase positive, grows in salt-containing media, darting/shooting motility

Answer 4

Vibrio

Question 5

Gram-negative bacillus, oxidase negative, white/colourless colonies on MacConkey agar, non-motile

Answer 5

Shigella

Question 6

Hospitalized, immunocompromised patient with sepsis, gram-negative rod, oxidase-negative, red pigment produced

Answer 6

Serratia

Question 7

Gram-negative bacillus, oxidase positive, urease-positive, upper epigastric pain, heartburn

Answer 7

Helicobacter

Question 8

Gram-negative curved bacillus, oxidase positive, grows in TCBS medium, reservoir in warm marine waters

Answer 8

Vibrio

Question 9

Gram-negative bacillus, oxidase negative, non-lactose-fermenting white/colourless colonies, swarming motility, urease-positive, kidney stones

Answer 9

Proteus

Question 10

Gram-negative bacillus, oxidase negative, lactose-fermenting pink colonies, common cause of sepsis in those with urinary tract infection with this bacterium

Answer 10

E. Coli

Question 11

Gram-negative rod, oxidase negative, does NOT ferment sorbitol, bloody diarrhea

Answer 11

Enterohemorrhagic E. Coli (EHEC)

Question 12

Gram-negative spiral-shaped (‘gull-wing”) bacillus, oxidase positive, grows in Skirrows medium at 42 degrees Celcius

Answer 12

Campylobacter