FIG 1.

Mutations in ampD conferring resistance to ceftazidime. (A) Map of the mutations on ampD. Positions of single-nucleotide substitution mutations resulting in amino acid substitutions or protein extension, duplications, deletions, and IS insertion are mapped. The numbers of occurrences of each mutation are shown in a bar graph. All mutations exhibited an MIC value around 64 μg/ml. Details of each mutation are provided in tables below the map. (B) Complementation analysis with the wild-type ampD. Restoration of ceftazidime susceptibility by intact ampD is observed with all mutations, but data for a few representative mutations are shown.