The inoculum effect of antibiotic susceptibility testing is often discussed at playgrounds and infectious diseases conferences, but many of us don’t really have a clear definition of what it is or a good understanding of its importance.

We’ll be talking about the inoculum effect and susceptibility testing of Staphylococcus aureus with cefazolin.

Some of the questions we’ll discuss are:
• What exactly is the inoculum effect and how is it measured?
• Does the inoculum effect have clinical significance?
• How common is the inoculum effect with Staph aureus and cefazolin?