Fig. 3.
Porin-dependent susceptibility of M. smegmatis to a disinfectant formulation in quantitative suspension tests (EN 14348). Homogenized cell suspensions of M. smegmatis wild type (triangles) and the ΔmspA ΔmspC ΔmspD mutant (ML16, circles) were exposed to 0.0625% (closed symbols) or 0.125% (open symbols) of the disinfectant formulation. After 5, 15, and 30 min, the antimicrobial activity was quenched with a neutralizer, and surviving cells were recovered on agar plates. The antimicrobial activity was expressed as logarithmical cell count reduction (reduction factor [RF]) of the initial cell inoculum. Black asterisks denote RF values, which are in fact higher but cannot be displayed due to the experimental setup demanded by the EN standard.