What is MCR 1

Department of Veterinary Medicine

Reports of bacterial pathogens that are difficult to treat with antibiotics have increased in recent years. Pathogens from the enterobacteria family, which are resistant to a large number of antibiotic agents, are particularly problematic. If there is also resistance to antibiotics of the carbapenem group, there are only a few alternatives for therapy. The polypeptide antibiotic colistin is one of the few remaining antibiotics that is still effective against infections with these multi- and carbapenem-resistant pathogens from the enterobacteria family. In November 2015, Chinese scientists published the discovery of a new resistance gene. Bacteria that named the gene mcr-1 wear, become insensitive to the antibiotic colistin. It is particularly alarming that the newly discovered resistance gene can be transferred between different bacterial strains and could theoretically spread easily.

The interdisciplinary research network RESET is primarily concerned with special resistance mechanisms that affect enterobacteria Escherichia coli and Salmonella enterica occur. The research network is coordinated by the University of Veterinary Medicine Hannover (Institute for Biometry, Epidemiology and Information Processing, Prof. Dr. Lothar Kreienbrock), the Free University of Berlin is involved with the Institute for Animal and Environmental Hygiene and the Institute for Food Hygiene. In cooperation with the German Center for Infection Research (DZIF), in particular with the DZIF location in Gießen: the Institute for Medical Microbiology, the project partners created an extensive collection of bacterial strains in various studies on the spread of such germs in animals, food and humans. The information on the origin of these samples and the results of corresponding laboratory tests were recorded in a joint database. For more in-depth analyzes, the Institute for Medical Microbiology in Gießen sequenced the genome for a selection of these bacterial strains. These sequencing data now made it possible to detect the newly discovered resistance gene mcr-1 in three pig isolates collected from 2011 and in the multi-resistant isolate from a person from 2014. In all four mcr-1-bearing isolates, the scientists also found other resistance genes, which limits the options for antibiotic treatment even more.

The research association was able to show for the first time that the resistance gene mcr-1 in Germany Escherichia coli occurs in livestock as well as in humans. Statements on the extent of the spread, on possible transmission routes or on the direction of transmission (from humans to animals or vice versa) cannot yet be made. What is clear, however, is that this resistance gene has been present in Germany at least since 2011 and that there has been a possibility of transmission to humans for several years. The scientists publish these results in the journal "The Lancet Infectious Diseases".

The resistance gene has also already been detected in other European countries. Since the first description in China, analyzes of available sequencing data in Denmark and England have shown that the new gene is in data collections too E. coli- or. Salmonella-Trunks that date back to 2012. Evidence in isolates from humans has also been reported in both countries. Further studies in Germany as well as in other countries are necessary in order to be able to estimate how long this resistance gene has been present and to what extent it is spread in bacteria of humans and animals. This is important to understand the extent of the problem.

The RESET research association and the German Center for Infection Research (DZIF) are funded by the Federal Ministry of Education and Research (BMBF).

The original publication in "The Lancet Infectious Diseases"

Colistin resistance gene mcr-1 in extended-spectrum β-lactamase-producing and carbapenemase-producing Gram-negative bacteria in Germany. Falgenhauer L, Waezsada SE, Yao Y, Imirzalioglu C, Käsbohrer A, Roesler U, Brenner Michael G, Schwarz S, Werner G, Kreienbrock L, Chakraborty T for the RESET consortium.


Professor Dr. Uwe Rösler
Free University of Berlin, Department of Veterinary Medicine
Institute for Animal and Environmental Hygiene in the Center for Infection Medicine
Tel .: +49 30 838-51830
Email: [email protected]

Professor Dr. Lothar Kreienbrock (coordinator RESET)
University of Veterinary Medicine Hannover Foundation
Institute for Biometry, Epidemiology and Information Processing
WHO-Collaborating Center for Research and Training for Health at the Human-Animal-Environment Interface
Tel .: +49 511 953-7950
Email: [email protected]