Colistin- and Carbapenem-Resistant Escherichia coli Harboring mcr-1 and blaNDM-5, Causing a Complicated Urinary Tract Infection in a Patient from the United States
mBIO August 30, 2016 V.7 N.4
José R. Mediavillaa, Amee Patrawallab, Liang Chena, Kalyan D. Chavdaa, Barun Mathemac, Christopher Vinnarda, Lisa L. Deverd, Barry N. Kreiswirtha
aPublic Health Research Institute Tuberculosis Center, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
bDivision of Pulmonary and Critical Care Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
cDepartment of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York, USA
dDivision of Infectious Diseases, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
Colistin is increasingly used as an antibiotic of last resort for the treatment of carbapenem-resistant Gram-negative infections. The plasmid-borne colistin resistance gene mcr-1 was initially identified in animal and clinical samples from China and subsequently reported worldwide, including in the United States.
Of particular concern is the spread of mcr-1 into carbapenem-resistant bacteria, thereby creating strains that approach pan-resistance. While several reports of mcr-1 have involved carbapenem-resistant strains, no such isolates have been described in the United States.
Here, we report the isolation and identification of an Escherichia coli strain harboring both mcr-1 and carbapenemase gene blaNDM-5 from a urine sample in a patient without recent travel outside the United States.
The isolate exhibited resistance to both colistin and carbapenems, but was susceptible to amikacin, aztreonam, gentamicin, nitrofurantoin, tigecycline, and trimethoprim-sulfamethoxazole.
The mcr-1- and blaNDM-5-harboring plasmids were completely sequenced and shown to be highly similar to plasmids previously reported from China.
The strain in this report was first isolated in August 2014, highlighting an earlier presence of mcr-1 within the United States than previously recognized.