Carbapenem resistant Enterobacteriaceae (CRE) are among the most severe threats to the antibiotic era. Multiple different species can exhibit resistance, resulting from many different mechanisms, and many different mobile elements are capable of transferring resistance between lineages. To identify routes of CRE transmission and the transfer of carbapenem resistance elements, we sequenced and compared the genomes of CRE isolated over a fifteen-month period from patients in Boston and California. Our analysis revealed unexpected diversity among strains and little evidence for clonal spread, yet apparent rampant horizontal transfer of resistance genes into susceptible genetic backgrounds via a combination of plasmid transfer and hopping of transposable elements. We identified isolates with unrecognizable mechanisms of carbapenem resistance and evidence for considerable asymptomatic carriage, indicating continued innovation by these organisms to thwart the action of this important class of antibiotics, and underscoring the need for continued surveillance of CRE. We are now expanding on our initial study to establish frameworks for understanding and identifying CRE evolution and outbreaks.
|Brigham and Women's Hospital, Boston||Thomas F. O'Brien, Lisa A. Cosimi, Andrew B. Onderdonk, Mary L. Delaney|
|Massachusetts General Hospital, Boston||Deborah T. Hung, Christopher M. Ernst, John P. Dekker, Mary J. Ferraro, David C. Hooper|
|Harvard School of Public Health, Boston||Yonatan H. Grad, William P. Hanage|
|School of Medicine, University of California, Irvine||Diane Kim, Ellena M. Peterson, Susan S. Huang|
|Beth Israel Deaconess Medical Center, Boston||James E. Kirby|
|Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Brazil|