Fig. 1

Efficacy of peracetic acid (PAA) using three different disinfectant testing methods. Bars show mean recovered CFUs after 10 min exposure to different concentrations of PAA of the K. pneumoniae outbreak strain and the type strain that were tested as: (a) planktonic cells (suspension test, EN 13727) (b) surface-fixed planktonic cells (carrier test, EN 14561) and (c) biofilm (Bead Assay for Biofilms). Disinfection was defined as ≥ 5log₁₀ reduction in mean recoverable CFUs and is marked by a dashed red line in the respective assays. At comparable PAA concentrations, the outbreak strain shows a higher number of recovered CFUs than the type strain in all three models. Experiments were performed in triplicates