Antimicrobial susceptibility testing using disc diffusion methods

Species-related interpretive breakpoints were introduced on a broad scale at the clinical microbiology laboratory in Lund, Sweden, in the late 1970:ies by Göran Kronvall, at that time responsible for clinical bacteriology laboratory services in Lund.

A.

Historical background and the concept of species-related interpretive zone breakpoints for SIR categorization.

How we started using species-related breakpoints.

B.

SRA, single strain regression analysis.

An objective method confirming the need for species-related interpretive breakpoints.

C.

Calibration of the disc diffusion test. Optimized disc content.

The only definition so far of setting the optimal disc content in disc diffusion testing is presented.

D.

The M-test for estimation of antimicrobial MIC values of clinical isolates.

This method links earlier studies by others to multi-disc testing.

E.

NRI, Normalized Resistance Interpretation, for comparative investigations of antimicrobial susceptibility.

The solution to standardized resistance surveys.