ChromID extended-spectrum beta-lactamase (ESBL) culture medium is routinely used 
for screening ESBL producers. This medium was tested for detecting 
carbapenemase-producing Enterobacteriaceae isolates from a collection of 
reference strains and compared to the CHROMagar KPC culture medium previously 
evaluated for detecting KPC-producing isolates. Producers of IMP-, VIM-, and 
KPC-type carbapenemases with high levels of resistance to cephalosporins and to 
carbapenems were detected at 1x10(1) CFU/ml. The OXA-48 producers were not 
detected on ChromID ESBL medium unless coexpressing ESBLs, whereas 
carbapenemase-producing isolates with MICs of <4 microg/ml were not detected on 
CHROMagar KPC medium.