A new resistance gene has been found in coli bacteria among pigs, broiler meat and humans in China. Bacteria with the same resistance gene have now also been found in Denmark, according to a new Danish study. The National Food Institute, Technical University of Denmark, and Statens Serum Institut have been able to quickly create an overview of the situation in Denmark because many bacteria have had their DNA-profile mapped with the help of whole genome sequencing.
A new resistance gene, mcr-1, has been found in coli bacteria among pigs, broiler meat and humans in China according to a scientific article in renowned journal The Lancet on 18 November 2015.
The gene leads to resistance to colistin – antimicrobials of the type polymyxin, which are the last available option to treat infections with multiresistant so-called gram negative bacteria such as fx E-coli and klebsiella.
Technology platform at DTU
Since 2009 the National Food Institute and DTU Systems Biology have built up computer facilities which are able to quickly map a bacteria’s genome – its DNA – and compare the results with bacterial findings from around the world. Many bacterial findings in Denmark have had their DNA profile mapped with the help of whole genome sequencing.
When the resistance gene, mcr-1, was made available to researchers on 23 November 2015, the National Food Institute in cooperation with Statens Serum Institut was able to quickly create an overview of the situation in Denmark for the Danish authorities.
Unlike previously when it was necessary to collect bacterial samples, set up new detection methods and carry our analysis, researchers can these days get an overview of the situation within hours thereby saving months of work.
The approximately 3000 gram negative coli- og salmonella bacteria, which have previously been mapped using whole genome sequencing, have been reexamined to see whether mcr-1 is present. Results show that mcr-1 was found in one patient, who suffered from a blood infection in 2015 and in five food samples that have been imported from 2012-2014. All the bacteria are multiresistant ESBL bacteria containing the mcr-1 gene, which can further complicate treatment.
The National Food Institute is working to develop global databases in order to further the intelligent use of whole genome sequencing data.
This work takes place in the network Global Microbial Identifier and the EU project COMPARE. Both have the aim of creating a global system of databases for whole genome sequencing. These databases will be used to identify and diagnose disease-causing microorganisms and infectious diseases. They will also make it possible to compare data with information on outbreaks and emerging disease-causing microorganisms.
The National Food Institute also performs the role of WHO Collaborating Centre and EU reference laboratory for antimicrobial resistance. As such, the reference laboratory is planning in agreement with the European Commission to examine the prevalence of mcr-1 in cooperation with national veterinary and food laboratories in the EU.
See the scientific article in The Lancet: Emergence of plasmid-mediated colistin resistance mechanism MCR-1 in animals and human beings in China: a microbiological and molecular biological study.
Read more about whole genome sequencing in a news story from May 2015: Uncovering foodborne outbreaks using the latest technology.