FIG. 1.

Schematic representation of the ade gene clusters from A. baumannii BM4454 and BM4454-1 and their environments. Open arrows indicate the direction of transcription. The genes encoding the three-component Ade efflux system are represented by boldface arrows. In pAT794, which conferred ticarcillin resistance (Tic^R), the sequence of pUC18 is hatched. Open arrowheads represent degenerate oligodeoxynucleotides O1 and O2 used to detect the adeB gene, and closed arrowheads represent specific oligodeoxynucleotides O3 and O4 used to generate pAT794. NheI restriction sites are indicated by vertical lines.