Molecular Characterization of Carbapenem-Resistant Enterobacterales Collected in the United States
Maria Karlsson, Joseph D. Lutgring, Uzma Ansari, Adrian Lawsin, Valérie Albrecht, Gillian McAllister, Jonathan Daniels, David Lonsway, Susannah L. McKay, Zintars G. Beldavs, Chris Bower, Ghinwa Dumyati, Annastasia Gross, Jesse T. Jacob, Sarah J. Janelle, Marion Kainer, Ruth Lynfield, Erin C. Phipps, Kyle Schutz, Lucy Wilson, Medora Witwer, Sandra N. Bulens, Maroya Spalding Walters, Nadezhda Duffy, Alexander J. Kallen, Christopher A. Elkins, J. Kamile Rasheed
Abstract
Carbapenem-resistant Enterobacterales (CRE) are a growing public health concern due to resistance to multiple antibiotics and potential to cause health care-associated infections with high mortality. Carbapenemase-producing CRE are of particular concern given that carbapenemase-encoding genes often are located on mobile genetic elements that may spread between different organisms and species. In this study, we performed phenotypic and genotypic characterization of CRE collected at eight U.S. sites participating in active population- and laboratory-based surveillance of carbapenem-resistant organisms. Among 421 CRE tested, the majority were isolated from urine ( n = 349, 83%). Klebsiella pneumoniae was the most common organism ( n = 265, 63%), followed by Enterobacter cloacae complex ( n = 77, 18%) and Escherichia coli ( n = 50, 12%). Of 419 isolates analyzed by whole genome sequencing, 307 (73%) harbored a carbapenemase gene; variants of bla KPC predominated ( n = 299, 97%). The occurrence of carbapenemase-producing K. pneumoniae , E. cloacae complex, and E. coli varied by region; the predominant sequence type within each genus was ST258, ST171, and ST131, respectively. None of the carbapenemase-producing CRE isolates displayed resistance to all antimicrobials tested; susceptibility to amikacin and tigecycline was generally retained.