Gram +/- Cheat Sheet

Question 1

Gram Negative Respiratory

Answer 1

• haemophilus influenzae (G- coccobacilli)

- moraxella catarrhalis (G- diplococci)

Question 2

Gram Negative Non-Fermenters (all GNB’s)

Answer 2

• pseudomonas sp
• acinetobacter sp
• stenotrophomonas maltophilia

Question 3

Gram Negative Enterics (all GNB’s)

Answer 3

• e. coli
• proteus
• klebsiella
• enterobacter
• serratia
• citrobacter
• salmonella
• yersinia
• shigella

Question 4

Gram Positive Staphylococcus (G+ cocci in clusters)

Answer 4

Coag +
- s. aureus

Coag -

• s. epidermidis
• s. saprophyticus

Question 5

Gram Positive Streptococcus

Answer 5

s. pneumoniae (G+ diplococci) 
Lancefield groups (G+ cocci in chains) 
- group A: s. pyogenes
- group B: s. agalactiae
- group C
- group D: s. bovis 
- group F

strep viridans

Question 6

Gram Positive Enterococcus (G+ cocci in chains)

Answer 6

e. faecalis

e. faecium

Question 7

Group A (s. pyogenes)

Answer 7

• strep throat
• necrotizing fasciitis (“flesh-eating bacteria”)
• rheumatic heart disease

Question 8

Group B (s. agalactiae)

Answer 8

• perinatal strep
• colonizer of vaginal canal
• neonatal sepsis
• invasive in obese patients

Question 9

Group C and F

Answer 9

• mostly colonizers (chronic wounds)

Question 10

Group D

Answer 10

• used to include enterococcus, now just S. bovis which if found in blood is thought to indicate colon cancer

Question 11

Strep Viridans

Answer 11

• S. milleri, S. anginosis, S. salivarius, S. mitis found in mouth, teeth, upper respiratory tract
• associated with endocarditis