Summary Types

Reports can have the following summaries:


The SIR Summary shows the number of samples which were susceptible, intermediate and resistant to each antibiotic. The breakpoints are included to show the concentration of the antibiotic which defines whether the sample is classified as susceptible or resistant.


The MIC Summary shows the minimum and maximum MICs from the isolates tested, the concentration that inhibited 50% of the isolates (MIC50) and the concentration that inhibited 90% of the isolates (MIC90).


This table shows the total number of isolates that were tested for each resistance mechanism and how many of those samples tested positive.


The MIC Distribution shows the number of isolates with each MIC.


The Isolates summary shows the number of isolates tested against each antibiotic.

Why do some antimicrobials appear in the MIC summary but not in the SIR summary?

There are two possible reasons for this. One is that there is no breakpoint for the organism/antimicrobial combination, so it is not possible to classify isolates as susceptible/intermediate/resistant. Another is that the combination is excluded: for example, MRSA are considered to be resistant to all beta-lactams, so individual beta-lactams are not included in the SIR tables for S. aureus or MRSA, but are included for MSSA.