TEM-72, a New Extended-Spectrum β-Lactamase Detected in Proteus mirabilis and Morganella morganii in Italy

Abstract
A new natural TEM-2 derivative, named TEM-72, was identified in a Proteus mirabilis strain and in a Morganella morganii strain isolated in Italy in 1999. Compared to TEM-1, TEM-72 contains the following amino acid substitutions: Q39K, M182T, G238S, and E240K. Kinetic analysis showed that TEM-72 exhibits an extended-spectrum activity, including activity against oxyimino-cephalosporins and aztreonam. Expression of bla TEM-72 in Escherichia coli was capable of decreasing the host susceptibility to the above drugs.