title: [Results from a German interlaboratory test to establish the broth microdilution method for the determination of the minimum inhibitory concentration of bacteria from animals].
abstract: In accordance with NCCLS guideline M31-A2, the DVG working group "antimicrobial resistance" developed a standard operating procedure (SOP) for the determination of the minimal inhibitory concentration (MIC) of antimicrobial agents by broth microdilution. This SOP was evaluated for its fitness for use in a national interlaboratory test. A total of 32 participating laboratories tested five strains (including two internationally accepted reference strains and three field strains representing in total three different bacterial species) three times at a one week interval each, using uniform microtitre plates. In 31 of the 32 laboratories more than 80% of MIC determinations performed yielded values in the expected range. In total 94.0% of the results were reproducible, with a lesser deviation of 4.0% from the expected values for laboratories performing MIC determination as a matter of routine (46.9%), compared to 7.9% for laboratories without such routine (53.1%). Comparing the consistency of results on the basis of the tested strains, a higher reproducibility of the results was observed for reference strains (96.1%) than for field strains (92.6%). In particular results obtained for the Streptococcus uberis field strain were afflicted with a higher error ratio (98 deviations from the expected values). Among the tested antimicrobial agents, a higher variability of results was recorded only for gentamicin with 16.7% divergent MIC determinations (mean value 6.0%). The high reproducibility of the results confirmed by this interlaboratory study underlines the robustness of the developed SOP as well as broth microdilutions as the method of choice for MIC determina tion.
authors.affiliation: Bundesamt für Verbraucherschutz und Lebensmittelsicherheit, Berlin. juergen.wallmann@bvl.bund.de
authors.forename: Jürgen
authors.initials: J
authors.lastname: Wallmann
authors.forename: Alexander
authors.initials: A
authors.lastname: Böttner
authors.forename: H Mohamed
authors.initials: HM
authors.lastname: Hafez
authors.forename: Corinna
authors.initials: C
authors.lastname: Kehrenberg
authors.forename: Manfred
authors.initials: M
authors.lastname: Kietzmann
authors.forename: Dieter
authors.initials: D
authors.lastname: Klarmann
authors.forename: Günter
authors.initials: G
authors.lastname: Klein
authors.forename: Peter
authors.initials: P
authors.lastname: Krabisch
authors.forename: Tilman
authors.initials: T
authors.lastname: Kühn
authors.forename: Gabriele
authors.initials: G
authors.lastname: Luhofer
authors.forename: Angelika
authors.initials: A
authors.lastname: Richter
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwarz
authors.forename: Claudia
authors.initials: C
authors.lastname: Sigge
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Traeder
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Waldmann
authors.forename: Christiane
authors.initials: C
authors.lastname: Werckenthin
authors.forename: Eva
authors.initials: E
authors.lastname: Zschiesche
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D001424:Bacterial Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D019411:Clinical Laboratory Techniques / Q000592:standards*; D024881:Drug Resistance, Bacterial; D005858:Germany; D008826:Microbial Sensitivity Tests / Q000592:standards / Q000662:veterinary*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000900:Anti-Bacterial Agents