Antimicrobial susceptibility of class-D-carbapenemase-producing E. coli (n = 103). x axis, MIC in mg/liter; y axis, number of isolates. A, ceftazidime; B, nitrofurantoin; C, fosfomycin; D, imipenem; E, amdinocillin; F, trimethoprim-sulfamethoxazole; S, susceptible; I, intermediate; R, resistant.