Genetic and biochemical characterization of CGB-1, an Ambler class B carbapenem-hydrolyzing beta-lactamase from Chryseobacterium gleum.
Chryseobacterium gleum (previously included in the Flavobacterium IIb species) is a gram-negative aerobe that is a source of nosocomial infections. An Ambler class B beta-lactamase gene was cloned and expressed in Escherichia coli from reference strain C. gleum CIP 103039 that had reduced susceptibility to expanded-spectrum cephalosporins and carbapenems. The purified beta-lactamase, CGB-1, with a pI value of 8.6 and a determined relative molecular mass of ca. 26 kDa, hydrolyzed penicillins; narrow- and expanded-spectrum cephalosporins; and carbapenems. CGB-1 was a novel member of the molecular subclass B1 of metallo-enzymes. It had 83 and 42% amino acid identity with IND-1 from Chryseobacterium indologenes and BlaB from C. meningosepticum, respectively. Thus, in addition to the previously characterized clavulanic acid-inhibited extended-spectrum beta-lactamase CGA-1 of Ambler class A, C. gleum produces a very likely chromosome-borne class B beta-lactamase.
Service de Bactériologie-Virologie, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, Faculté de Médecine Paris-Sud, 94275 Le Kremlin-Bicêtre Cédex, France.
Samuel
S
Bellais
Thierry
T
Naas
Patrice
P
Nordmann
D000595:Amino Acid Sequence; D001419:Bacteria / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D015780:Carbapenems / Q000494:pharmacology*; D019818:Clavulanic Acid / Q000494:pharmacology; D003001:Cloning, Molecular; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000032:analysis; D004274:DNA, Recombinant / Q000235:genetics; D004351:Drug Resistance; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017403:In Situ Hybridization; D007525:Isoelectric Focusing; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics*
D015780:Carbapenems; D004269:DNA, Bacterial; D004274:DNA, Recombinant; D004791:Enzyme Inhibitors; D019818:Clavulanic Acid; D001618:beta-Lactamases; C471025:beta-lactamase CGB-1, Chryseobacterium gleum