CMY-16, a novel acquired AmpC-type beta-lactamase of the CMY/LAT lineage in multifocal monophyletic isolates of Proteus mirabilis from northern Italy.

ABSTRACT: We report multifocal detection (four different cities in northern Italy) of Proteus mirabilis isolates resistant to both oxyimino- and 7-alpha-methoxy-cephalosporins and producing a novel acquired AmpC-like beta-lactamase. The enzyme, named CMY-16, is a variant of the CMY/LAT lineage, which differs from the closest homologues, CMY-4 and CMY-12, by a single amino acid substitution (A171S or N363S, respectively) and from CMY-2 by two substitutions (A171S and W221R). Expression of the cloned bla(CMY-16) gene in Escherichia coli decreased susceptibility to penicillins, cephalosporins, and aztreonam. Tazobactam was more effective than clavulanate at antagonizing the enzyme activity. Genotyping, by random amplification of polymorphic DNA and pulsed-field gel electrophoresis of genomic DNA digest

SUBMITTER: D'Andrea MM 

PROVIDER: S-EPMC1366893 | biostudies-literature | 2006 Feb

REPOSITORIES: biostudies-literature