Clinical outcomes of patients with Klebsiella pneumoniae carbapenemase-producing K. pneumoniae after treatment with imipenem or meropenem.

Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae may appear susceptible to imipenem or meropenem by routine susceptibility testing. We report a series of patients with infections caused by K. pneumoniae isolates, which yielded imipenem-susceptible results but were subsequently KPC-positive by polymerase chain reaction. When these infections were treated with imipenem or meropenem, frequent clinical and microbiologic failures were observed.