Colistin-Resistant, Klebsiella pneumoniae Carbapenemase (KPC)-Producing Klebsiella pneumoniae Belonging to the International Epidemic Clone ST258

Five cases of infection due to colistin-resistant, Klebsiella pneumoniae carbapenemase-producing K. pneumoniae belonging to the international epidemic clone ST258 occurred over a 4-month period. These cases likely represented both emergence of resistance and transmission of resistant organism. The colistin-resistant isolates were able to persist in the absence of selective pressure in vitro.