AST of bacteria

EUCAST panel S. pneumoniae and betalactam agents

The panel consists of 10 strains of Streptococcus pneumoniae with reference MIC values (mg/L) representing varying levels of susceptibility to beta-lactam agents, from wild type isolates to highly resistant. However, although the selection of strains is based on the level of betalactam susceptibility, reference MIC values for many other antibiotics are available.

Listed MICs represent consensus MICs from 6 repeated tests using broth micro-dilution according to ISO 20776-1 on freeze-dried panels using MH-F broth (Mueller-Hinton broth with 5% lysed horse blood and 20 mg/L β-NAD).

The 10 strains were selected, tested and quality controlled before and after freeze drying by the EUCAST Development Laboratory. The freeze dried material is prepared by and available from CCUG (Culture Collection at University of Gothenburg, Sweden).

This collection can be used together with S. pneumoniae ATCC 49619 to evaluate MIC methods for S. pneumoniae. and with the help of a current breakpoint table also the performance of other AST methods.

 

MICs should, irrespective of method used, comply with the consensus MICs, either being identical or with a value which is within ±1 dilution of the reference. Some degree of random variation is accepted whereas systematic deviation (i.e. MICs for a specific agent or several agents being systematically lower or higher than consensus MICs) should be further investigated, even if MICs are within ± 1 dilution of consensus MICs.

 

The EUCAST/CCUG collection is procured under the same rules as for other type culture collection strains.