GES-11, a Novel Integron-Associated GES Variant in Acinetobacter baumannii

New extended-spectrum β-lactamase GES-11 was detected in Acinetobacter baumannii BM4674. The enzyme conferred resistance to β-lactams, including aztreonam, and reduced susceptibility to carbapenems. The structural gene was part of a class 1 integron borne by self-transferable plasmid pIP847. GES-type β-lactamases have not been reported previously in A. baumannii.