Naturally occurring class a ß-lactamases from the Burkholderia cepacia complex

Abstract

Chromosomally encoded ß-lactamases from the Burkhotderia cepacia complex species (formerly Pseudomonas cepacia) were characterized. Cloning and sequencing identified an Ambler class A ß-lactamase (PenB) from B. cenocepacia. It shares 82% amino acid identity with the PenA ß-lactamases previously identified from B. multivorans 249. Its expression was dependent upon a LysR-type regulatory protein. Its narrow-spectrum hydrolysis activity mostly included penicillins but also included expanded-spectrum cephalosporins and aztreonam at lower levels. In that study, Pen-like ß-lactamases (PenC, PenD, PenE, PenF) that shared 63 to 92% identity with PenB from B. cenocepacia were identified from other Burkhotderia species. The corresponding B-lactamase genes might be used as genetic tools for accurate Burkhotderia species identification. Copyright © 2009, American Society for Microbiology. All Rights Reserved.