Molecular characterization of a carbapenem-hydrolyzing β-lactamase fromChryseobacterium(Flavobacterium)indologenes

Abstract

Chryseobacterium (Flavobacterium) indologenes 001 clinical strain was resistant to several β-lactam classes including carbapenems. Shotgun cloning experiments of Sau3AI restricted genomic DNA of C. indologenes 001 into pBKCMV cloning vector followed by transformation into Escherichia coli DH10B gave one recombinant plasmid possessing a 4.2-kb DNA insert. It encoded a pI 7.2 β-lactamase of 239 amino acids (IND-1) which is a metallo-enzyme with a broad spectrum β-lactam hydrolysis profile. This class B carbapenem-hydrolyzing β-lactamase shares the highest identity (43%) with BlaB from C. meningosepticum, thus showing heterogeneity of carbapenem-hydrolyzing β-lactamases in Chryseobacterium spp.