Molecular Characterization of β-Lactamase Genes and Their Genetic Structures in Acinetobacter Genospecies 3 Isolates in Taiwan

The genetic structure of beta-lactamases in Acinetobacter genospecies 3 (AG3) isolates in Taiwan was studied to analyze their high rates of resistance to beta-lactams, including carbapenems (57.9%). bla(IMP-1) and bla(IMP-8) were located in a class 1 integron. bla(OXA-58) was bracketed by ISAba3. A novel TnpF-like integrase gene was identified upstream of bla VEB-3. Adjacent to the 5' sequence of the bla ADC gene, folE was identified. Four new Acinetobacter-derived cephalosporinase (ADC) enzymes were found, which clustered phylogenetically with published AG3 ADC proteins.