Plate Rounds

1
Plate Rounds

• Ellen Foxman
• June 26, 2003

2
Case 1

• 26 year old woman with AML
• TPN
• Blood cx Coag negative Staph

3
MLS Antibiotics Macrolides (Erythromycin),
Lincosamides (Clindamycin), and Streptogramins

• Bind ribosome and inhibit protein synthesis
• Mechanisms of resistance
• Efflux
• erm gene (Staph) enzyme modifies ribosome so
  that antibiotics cannot bind

Drugs and Bugs website http//www.geocities.com/k
rbushcalgary/gps.htmthree
4
erm gene

• Constitutive or
• Inducible
• Only seen when exposed to a macrolide
  (erythromyicn)
• Appears clinda susceptible, but will be clinda
  resistant if gene induced
• Eyrthromycin-resistant Staph Aureus We will not
  report clinda susceptibility

5
Kirby-Bauer platesStaph aureus with erm pattern
6
Case 2

• 64 year old woman, s/p skull base surgery with
  trans-oral approach
• Received introoperative clindamycin
• Sputum sent for culture
• Normal oral flora with unusual predominance
• Eikenella corrodens
• H. parainfluenza

7
HACEK organisms

• Hemophilus (Heme loving X, V)
• H. aphrophilus
• H. parainfluenzae (V)
• H. paraphrophilus (V)
• Actinomyces actinomycetemcomitans
• Cardiobacterium hominis
• Eikenella corrodens
• Kingella kingii

8
Eikenella corrodens Hemophilus parainfluenza
9
Eikenella
10
Typical oral flora