Genetic and biochemical characterisation of OXA-232, a carbapenem-hydrolysing class D β-lactamase from Enterobacteriaceae

Three enterobacterial isolates (two Klebsiella pneumoniae and one Escherichia coli) were recovered from three patients transferred from India to France in 2011. All three isolates were resistant or of intermediate susceptibility to all beta-lactams and of decreased susceptibility to carbapenems. These three isolates expressed a novel carbapenem-hydrolysing beta-lactamase, OXA-232, differing from OXA-181 and OXA-48 by one and five amino acid substitutions, respectively. Compared with OXA-181, OXA-232 had a lower ability to hydrolyse carbapenems but conversely possessed higher hydrolytic activities against penicillins. The bla(OXA-232) gene was located on a 6.1-kb ColE-type non-conjugative plasmid. (C) 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.