Send to

Choose Destination
Clin Infect Dis. 2018 Sep 11. doi: 10.1093/cid/ciy683. [Epub ahead of print]

Transmission of Mobile Colistin Resistance (mcr-1) by Duodenoscope.

Author information

Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA.
Infection Control Unit, Massachusetts General Hospital, Boston, MA.
Department of Medicine, Harvard Medical School, Boston, MA.
Microbiology Laboratory, Pathology Service, Massachusetts General Hospital, Boston, MA.
Pediatric Infectious Disease Unit, MassGeneral Hospital for Children, Boston, MA.
Department of Pathology, Harvard Medical School, Boston, MA.
Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, GA.
Bureau of Infectious Disease and Laboratory Sciences, Massachusetts Department of Public Health, Boston, MA.
Bureau of Health Care Safety and Quality, Massachusetts Department of Public Health, Boston, MA.



Clinicians increasingly utilize polymyxins for treatment of serious infections caused by multidrug-resistant gram-negative bacteria. Emergence of plasmid-mediated, mobile colistin resistance genes creates potential for rapid spread of polymyxin resistance. We investigated the possible transmission of Klebsiella pneumoniae carrying mcr-1 via duodenoscope and report the first documented healthcare transmission of mcr-1-harboring bacteria in the United States.


A field investigation, including screening targeted high-risk groups, evaluation of the duodenoscope, and genome sequencing of isolated organisms, was conducted. The study site included a tertiary care academic health center in Boston, Massachusetts, and extended to community locations in New England.


Two patients had highly related mcr-1-positive K. pneumoniae isolated from clinical cultures; a duodenoscope was the only identified epidemiological link. Screening tests for mcr-1 in 20 healthcare contacts and 2 household contacts were negative. K. pneumoniae and E. coli were recovered from the duodenoscope; neither carried mcr-1. Evaluation of the duodenoscope identified intrusion of biomaterial under the sealed distal cap; devices were recalled to repair this defect.


We identified transmission of mcr-1 in a United States acute care hospital that likely occurred via duodenoscope despite no identifiable breaches in reprocessing or infection control practices. Duodenoscope design flaws leading to transmission of multidrug-resistant organsisms persist despite recent initiatives to improve device safety. Reliable detection of colistin resistance is currently challenging for clinical laboratories, particularly given the absence of an FDA-cleared test; improved clinical laboratory capacity for colistin susceptibility testing is needed to prevent the spread of mcr-carrying bacteria in healthcare settings.


Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center