title: Characterization of a laboratory-generated variant of BPS beta-lactamase from Burkholderia pseudomallei that hydrolyses ceftazidime.
abstract: Burkholderia pseudomallei produces an Ambler class A beta-lactamase, known as BPS-1. The beta-lactamase gene from a laboratory-derived, ceftazidime-resistant strain of B. pseudomallei (LH-1-2) was cloned and expressed in Escherichia coli. The beta-lactamase, named BPS-1m, had an identical isoelectric focusing point (pI 7.7) to that of BPS-1, but differed in having a stronger hydrolytic activity against ceftazidime. Susceptibility testing showed that BPS-1m when expressed in E. coli conferred resistance to ceftazidime (MIC >or= 32 mg/L). The amino acid sequence of BPS-1m differed from that of BPS-1 by a Pro-to-Ser change at position 167 in the omega loop.
authors.affiliation: Department of Microbiology and HKU-Pasteur Research Centre, Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Pokfulam, Hong Kong SAR, China. plho@hkucc.hku.hk
authors.forename: P L
authors.initials: PL
authors.lastname: Ho
authors.forename: Terence K M
authors.initials: TK
authors.lastname: Cheung
authors.forename: W C
authors.initials: WC
authors.lastname: Yam
authors.forename: K Y
authors.initials: KY
authors.lastname: Yuen
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D016957:Burkholderia pseudomallei / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D002442:Ceftazidime / Q000378:metabolism*; D014644:Genetic Variation; D006801:Humans; D006868:Hydrolysis; D018440:beta-Lactam Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D002442:Ceftazidime; D001618:beta-Lactamases