Prevalence of mcr-1 in E. coli from Livestock and Food in Germany, 2010-2015

PLoS One. 2016 Jul 25;11(7):e0159863. doi: 10.1371/journal.pone.0159863. eCollection 2016.

Abstract

Since the first description of a plasmid-mediated colistin resistance gene (mcr-1) in November 2015 multiple reports of mcr-1 positive isolates indicate a worldwide spread of this newly discovered resistance gene in Enterobacteriaceae. Although the occurrence of mcr-1 positive isolates of livestock, food, environment and human origin is well documented only few systematic studies on the prevalence of mcr-1 are available yet. Here, comprehensive data on the prevalence of mcr-1 in German livestock and food isolates are presented. Over 10.600 E. coli isolates from the national monitoring on zoonotic agents from the years 2010-2015 were screened for phenotypic colistin resistance (MIC value >2 mg/l). Of those, 505 resistant isolates were screened with a newly developed TaqMan-based real-time PCR for the presence of the mcr-1 gene. In total 402 isolates (79.8% of colistin resistant isolates) harboured the mcr-1 gene. The prevalence was depending on the food production chain. The highest prevalence was detected in the turkey food chain (10.7%), followed by broilers (5.6%). A low prevalence was determined in pigs, veal calves and laying hens. The mcr-1 was not detected in beef cattle, beef and dairy products in all years investigated. In conclusion, TaqMan based real-time PCR provides a fast and accurate tool for detection of mcr-1 gene. The overall detection rate of 3.8% for mcr-1 among all E. coli isolates tested is due to high prevalence of mcr-1 in poultry production chains. More epidemiological studies of other European countries are urgently needed to assess German prevalence data.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Drug Resistance, Bacterial / genetics
  • Escherichia coli / drug effects
  • Escherichia coli / genetics*
  • Escherichia coli Infections / veterinary*
  • Escherichia coli Proteins / genetics*
  • Food Microbiology*
  • Germany
  • Humans
  • Livestock / microbiology*
  • Public Health Surveillance
  • Real-Time Polymerase Chain Reaction

Substances

  • Anti-Bacterial Agents
  • Escherichia coli Proteins
  • MCR-1 protein, E coli

Grants and funding

This work was in part supported by a grant to the RESET consortium through the German Federal Ministry of Education and Research (BMBF; grant number 01KI1313B) and a grant of the Federal Institute for Risk Assessment (1322-648). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.