Researchers from the German Center for Infection Research (DZIF) and the University of Giessen have shown that the gene for resistance to colistin, which was recently discovered in China, also exists in Germany. This finding is alarming, because colistin is the last-resort antibiotic for infections with multidrug-resistant bacteria. The results are currently published in The Lancet Infectious Diseases.
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.
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.
In the collection, a human isolate from 2014 that not only carried the newly discovered colistin resistance gene mcr-1 but was additionally resistant to carbapenem was identified. Carbapenems are globally considered to be last-resort broad spectrum antibiotics, used to treat emergency cases of multidrug-resistant bacterial infections. If dual resistance to both carbapenems and colistin exists, a fatal situation with no more treatment options can arise. This is therefore particularly alarming news for the health care system.
In veterinary medicine, colistin is especially used to treat pigs and cows with severe courses of infection. In Germany, the mcr-1 resistance gene was discovered in animals in 2010. According to the current scientific reports from China, a possible transmission to humans cannot be ruled out.
“This large collection of multidrug-resistant genome sequences in a specialised database was a prerequisite for identifying the mcr-1 gene rapidly. The database, established by the Bioinformatics Department, was groundbreaking and impressively demonstrates the potential of genomic epidemiology,” explains Professor Trinad Chakraborty, scientific coordinator at the DZIF and Director of the Institute of Medical Microbiology in Giessen. For DZIF Chairman Professor Martin Krönke, these current results are further evidence of the threatening development and global spread of resistance. "With the Friedrich-Löffler-Institut and Robert Koch Institute at the DZIF, we have the entire range of expertise at hand, as well as capabilities that enable us to confront this global challenge for both humans and animals.”
The DZIF and the research consortium RESET are funded by the German Federal Ministry of Education and Research (BMBF). RESET is an interdisciplinary research consortium which represents the Friedrich-Löffler-Institut und das Robert Koch Institute, amongst other institutions.