Chromosome-Encoded Ambler Class D β-Lactamase of Shewanella oneidensis as a Progenitor of Carbapenem-Hydrolyzing Oxacillinase

摘要

A chromosome-encoded β-lactamase gene from a Shewanella oneidensis reference strain was cloned and expressed in Escherichia coli. It encoded a carbapenem-hydrolyzing Ambler class D β-lactamase, OXA-54, that shared 92% amino acid identity with the plasmid-encoded carbapenem-hydrolyzing oxacillinase OXA-48 from Klebsiella pneumoniae. This work suggests that Shewanella spp. may produce the progenitor of oxacillinases compromising the efficacy of imipenem in clinically relevant gram-negative pathogens.