Evaluation of three selective chromogenic media, CHROMagar ESBL, CHROMagar CTX-M and CHROMagar KPC, for the detection of Klebsiella pneumoniae producing OXA-48 carbapenemase.

Three selective chromogenic culture media (CHROMagars ESBL, CTX-M and KPC) were evaluated for their ability to support the growth of nine Klebsiella pneumoniae isolates producing OXA-48 carbapenemase in combination with other β-lactamases. CHROMagar ESBL and CHROMagar KPC were the most sensitive media, supporting growth of all isolates with a detection limit as low as < 100 CFU/ml. Five isolates failed to grow on CHROMagar CTX-M, and five were recovered on CHROMagar KPC only at counts > 10(6) CFU/ml. Both CHROMagar ESBL and CHROMagar KPC may be useful for enhanced isolation of K pneumoniae producing OXA-48-like carbapenemases.