Antimicrobial Susceptibility Testing (AST) miniseries

Look at this episode first:

92. AST: What is Resistance anyway? (S/I/R) (1)

Definitions to understand

When are there ARE breakpoints

The first and very important question is, when are there no breakpoints in the EUCAST breakpoint tables?

Where to find clinical breakpoints:

EUCAST clinical breakpoint tables (updated yearly)

CLSI main other option (not discussed further here)

Using the EUCAST clinical breakpoints table (S/I/R + “-” + “IE”)

There are three main options in the breakpoints table

1. Breakpoint is listed
   1. Some breakpoints are “bracketed”
   2. Some are specified for specific indications
   3. Some have “notes” applied
2. “-”
3. “IE”

We’ve worked through these features with examples below

Let’s look at an example for Acinetobacter testing against Fluoroquinolones (EUCAST Clinical Breakpoints v15)

Breakpoint is listed

“-”