CMY-31 and CMY-36 Cephalosporinases Encoded by ColE1-Like Plasmids

Two CMY-2 derivatives, CMY-31 (Gln215→Arg) from Salmonella enterica serotype Newport and CMY-36 (Ala77→Cys and Gln193→Glu) from Klebsiella pneumoniae, were characterized. Both cephalosporinases functionally resembled CMY-2. blaCMY alleles occurred as parts of a putative transposon comprising ISEcp1B and a Citrobacter freundii-derived sequence carried by ColE1-like plasmids similar to CMY-5-encoding pTKH11 from Klebsiella oxytoca.