Open AccessGenetic and Biochemical Characterization of CGB-1, an Ambler Class B Carbapenem-Hydrolyzing β-Lactamase from Chryseobacterium gleum
Author(s) -
Samuel Bellais,
Thierry Naas,
Patrice Nordmann
Publication year - 2002
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.46.9.2791-2796.2002
Subject(s) - chryseobacterium , microbiology and biotechnology , biology , clavulanic acid , escherichia coli , cephalosporin , carbapenem , flavobacterium , enterobacteriaceae , beta lactamase , bacteria , amoxicillin , gene , biochemistry , antibiotics , genetics , 16s ribosomal rna , pseudomonas
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.