MCR 1 Total Bacterial Resistance
A new gene has been identified in enteric gram-negative bacteria that may lead to untreatable bacterial infections. The mcr-1 gene confers resistance to polymixin antibiotics, such as colistin, which is currently considered last-line therapy.
The mcr-1 gene is plasma-mediated, meaning it can easily be transmitted from one bacterium to another. The majority of mcr-1 expressing bacteria have been reported in livestock in 12 southeast Asian and European countries where colistin is used in food production. However, a small number of human infections have already been reported. The mcr-1 gene has been dectected in enteric bacteria such as Escherichia coli and Klebsiella pneumonia. Even more distressing is the finding that these gram-negative bacteria can also harbor genes for extended spectrum beta lactamases (ESBL) and carbapenemases. Simultaneous expression of these resistance genes will result in bacteria that are resistant to all currently available antibiotics.
Reference
Yi-Un L, etal. Emergence of plasmid-mediated colistin resistance mechanism MCR-1 in animals and human beings in China: a microbiological and molecular biological study. The Lancet Infectious Diseases, February 2016;16:161-168.
http://dx.doi.org/10.1016/S1473-3099(15)00424-7
