Novel carbapenem-hydrolyzing oxacillinase OXA-62 from Pandoraea pnomenusa.
Pandoraea spp. are gram-negative, glucose nonfermenting rods detectable in blood cultures and sputa of cystic fibrosis patients. They are resistant to various antibiotic groups, with imipenem being the only active beta-lactam. We isolated an imipenem-resistant (MIC, 64 microg/ml) Pandoraea pnomenusa strain from a cystic fibrosis patient. Cloning and sequencing identified two beta-lactamases of Bush group 2d, namely, the known OXA-33, located on an integron, and the novel carbapenem-hydrolyzing oxacillinase OXA-62. OXA-62 is only distantly related to other oxacillinases (OXA-50 being closest with 43% amino acid identity). It hydrolyzes penicillins, oxacillin, imipenem, and meropenem but not expanded-spectrum cephalosporins. The blaOXA-62 gene is chromosome located. No transposable elements were found in its genetic neighborhood. With OXA-62-specific primers, blaOXA-62 could be identified in all P. pnomenusa strains and appears to be species specific. This additional mechanism of carbapenem resistance further complicates the treatment of infections caused by P. pnomenusa.
MICOER Institute, Hesseloherstrasse 4, 80802 Munich, Germany.
Ines
I
Schneider
Anne Marie
AM
Queenan
Adolf
A
Bauernfeind
D000595:Amino Acid Sequence; D020562:Betaproteobacteria / Q000187:drug effects / Q000201:enzymology*; D015780:Carbapenems / Q000378:metabolism*; D024881:Drug Resistance, Bacterial; D006868:Hydrolysis; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D001618:beta-Lactamases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism
D015780:Carbapenems; D001618:beta-Lactamases; C108449:oxacillinase