 | ||
The mobilized colistin resistance (mcr-1) gene confers plasmid-mediated resistance to colistin, one of a number of last-resort antibiotics for treating gram negative infections. mcr-1 is capable of horizontal transfer between different strains of a bacterial species and after discovery in November 2015 in E. coli (strain SHP45) from a pig in China it has been found in Escherichia coli, Salmonella enterica, Klebsiella pneumonia, Enterobacter aerogenes, and Enterobacter cloacae.As of 2017 it has been detected in more than 30 countries on 5 continents in less than a year.
Contents
Description
The "mobilized colistin resistance"(mcr-1) gene confers plasmid-mediated resistance to colistin, a polymyxin and one of a number of last-resort antibiotics for treating infections.
mcr-1 is the first polymyxin resistance gene known to be capable of horizontal transfer between different strains of a bacterial species. The gene has been found in at least five species of bacteria: Escherichia coli, Salmonella enterica, Klebsiella pneumonia, Enterobacter aerogenes, and Enterobacter cloacae. It has been experimentally transferred in the lab from E. coli to Pseudomonas aeruginosa.
Discovery and geographical spread
The gene was first discovered in E. coli (strain SHP45) from a pig in China April 2011 and published in November 2015. It was identified by independent researchers in human samples from Malaysia, China, England, and the United States.
In April 2016, a 49-year-old woman sought medical care at a Pennsylvania clinic for UTI symptoms. PCR of an E. coli isolate cultured from her urine revealed the mcr-1 gene for the first time in the US, and the CDC sent an alert to health care facilities. In the following twelve months, four additional people were reported to have infections with mcr-1 carrying bacteria.
As of February 2017 mcr-1 has been detected in more than 30 countries on 5 continents in less than a year, and it appears to be spreading in hospitals in China. The prevalence in five Chinese provinces between April 2011 and November 2014 was 15% in raw meat samples and 21% in food animals during 2011–14, and 1% in people hospitalized with infection.