Over the last years, reports on bacterial pathogens which are resistant to available antibiotics have been increasing. Colistin is often one of the few last-resort antibiotics that can be used to treat infections with such multidrug-resistant pathogens. In November 2015, researchers in China discovered a new resistance gene, mcr-1, which now also makes bacteria resistant to colistin. Especially worrying is that, in contrast to previously known colistin resistance, this newly discovered mcr-1 resistance gene is transferable between different bacterial strains, and could therefore theoretically spread easily.
Interdisciplinary research consortium "RESET"
Since 2013, scientists in the DZIF research field “Healthcare-associated and Antibiotic-resistant bacterial Infections” have been working together closely with the interdisciplinary research consortium "RESET" at the Institute of Medical Microbiology of the Justus-Liebig-University of Gießen, collecting multidrug resistant pathogens from both animals and humans. The hereditary information of the isolates in this extensive collection was sequenced at the DZIF Bioinformatics Department, and the bacterial genomes were recorded in a database. This genome database has now been successfully used to determine the potential spread of this newly discovered resistance gene.
Resistance MCR-1 detected in Germany for the first time
The research group was able to show for the first time that the resistance mcr-1 in Germany occurs in Escherichia coli in animals and in humans. Statements regarding the extent of spread, the possible transmission paths or the direction of transmission (from humans to animals or vice versa) can yet not be taken. It is clear, however, that this resistance exixts at least since 2011 in Germany and thus the possibility of transmission to humans has been there for several years. These results were published by the researchers the journal "The Lancet Infectious Diseases".
Proof also in other European countries
The resistance gene has been previously detected in other European countries. Analysis of available sequence data in Denmark and England led to the fact that the new gene can be found in data collections to E.coli or Salmonella strains, dating back until 2012. In both countries evidence was also reported in isolates from humans. Further studies in Germany as well as in other countries are required in order to estimate since when this resistance occurs and to what extent it is common in bacteria from humans and animals. This is important in order to obtain information about the extent of the problem.
Presence of plasmid-encoded colistin resistance mediated by mcr-1 in extended spectrum β-lactamase- and carbapenem-producing Gram-negative isolates from animal and human populations 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.
The Lancet Infectious Diseases, Correspondence
(Veröffentlicht: 8. Januar 2016)