For the first time in the United States, researchers at the Multidrug Resistant Organism Repository and Surveillance Network (MRSN) at the Walter Reed Army Institute of Research (WRAIR) found a person carrying bacteria that is resistant to the last resort antibiotic colistin. The antibiotic-resistant strain of E. coli, which carries the mcr-1 gene, was discovered last week in the urine of a 49 year old Pennsylvania woman who had symptoms of a UTI. The authors wrote "the recent discovery of a plasmid-borne colistin resistance gene, mcr-1, heralds the emergence of truly pan-drug resistant bacteria."
Colistin is the antibiotic of last resort used to combat bacteria that are resistant to the strongest antibiotics. According to Infection Control Today, "colistin has remained the best tool available to treat multi drug resistant bacteria because bacteria were not exchanging genes for its resistance." However with this latest discovery, and other discoveries being reported in China, Europe, and Canada, it is shown that colistin is losing its effectiveness. Health officials are also concerned that the mcr-1 gene may spread to other bacteria rendering those bacteria to also become antibiotic resistant.
"Colistin is one of the last efficacious antibiotics for the treatment of highly resistant bacteria. The emergence of a transferable gene that confers resistance to this vital antibiotic is extremely disturbing. The discovery of this gene in the U.S. is equally concerning, and continued surveillance to identify reservoirs of this gene within the military healthcare community and beyond is critical to prevent its spread," reported Dr.Patrick McGann, MRSN, WRAIR. The colistin resistant bacteria was also discovered in swine infections both in China, the U.K., and the United States, although there is no evidence linking these events.
This new discovery has caused an urgent public health response to contain and prevent the spread of mcr-1. Through active surveillance and collection in individuals with the gene and potential to have the gene, researchers may be able to identify the origin of mcr-1 in order to best treat the bacteria. There is an urgency to take action and work on antibiotic stewardship and infection control for mcr-1 resistance. Scientists and public health officials have long warned that if the bacteria continue to spread, treatment options will be limited. Routine operations could become deadly and minor infections life-threatening.