Emergence of dual and multicarbapenemase coproducing organisms in the United States.

Carbapenemase-producing organisms commonly carry a single carbapenemase gene conferring resistant to carbapenems and other β-lactam antibiotics. Here, we report rare cases of multidrug-resistant Pseudomonas aeruginosa , Klebsiella pneumoniae, and Acinetobacter baumannii strains that coproduce multiple carbapenemases and exhibit extensive drug resistance. Such resistant strains are rarely identified in the United States.