Intrinsic Carbapenem-Hydrolyzing Oxacillinases from Members of the Genus Pandoraea

We analyzed the oxacillinases of isolates of six different species of Pandoraea, a genus that colonizes the respiratory tract of cystic fibrosis patients. The isolates produced carbapenem-hydrolyzing enzymes causing elevated MICs for amoxicillin, piperacillin, meropenem, and imipenem when expressed in an Escherichia coli host strain. Sequencing revealed nine new oxacillinases (OXA-151 to OXA-159) with a high degree of identity among isolates of the same species; however, they had much lower interspecies similarities. The intrinsic oxacillinase genes might therefore be helpful for correct identification of Pandoraea isolates.