Abstract
ABSTRACTColistin 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.
Highlights
Colistin is increasingly used as an antibiotic of last resort for the treatment of carbapenem-resistant Gram-negative infections
Polymyxins are increasingly used as antibiotics of last resort for clinical infections caused by carbapenem-resistant Gramnegative bacteria, especially carbapenem-resistant Enterobacteriaceae (CRE) [1]
Of particular concern is the spread of mcr-1 into CRE, thereby creating highly drug-resistant strains that are potentially untreatable
Summary
Colistin is increasingly used as an antibiotic of last resort for the treatment of carbapenem-resistant Gram-negative infections. The recent discovery of transmissible colistin resistance in China [2] has led to numerous reports of the plasmid-borne gene mcr-1 in animal, food, and clinical samples worldwide [3]. Several reports outside the United States have already described mcr-1 in bacterial strains harboring carbapenemases, including NDM-1 [4], NDM-5 [5,6,7], NDM-9 [8], KPC-2 [9], OXA-48 [10], and VIM-1 [11].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
