Circulation of pathogenic and multidrug resistant Escherichia coli in animals

点击翻译按钮获取中文摘要

Escherichia coli are common bacteria in the intestinal microbiota, and include a broad variety of different clones, ranging from highly pathogenic E. coli causing severe disease in animals to non-pathogenic commensal E. coli. A high prevalence of antimicrobial resistance has been found in pathogenic and commensal E. coli isolates. Presently, both the pig and poultry industries are at a crossroad, with few alternatives for treatment of the resulting almost epidemic E. coli infections. However, little is known of how these strains are able to succeed in emerging and spreading and what bacterial or other factors may influence this.The overall goal of this research program is to investigate the spatio-temporal spread of antimicrobial resistant and pathogenic E. coli in pigs and poultry on-farm and to identify risk factors influencing this spread. We are using two models to help achieve this goal. 1- Withdrawal by the poultry industry of systematic administration of an antimicrobial to all chicks prior to hatching and 2-Emergence and epidemic spread of highly pathogenic and extensively drug resistant E. coli strains in pigs where preventive antimicrobial medication is used after weaning.In both models, a similar approach will be used for the characterization of E. coli isolates in order to investigate the mechanisms of emergence or disappearance of new extensively drug resistant clones and the relative role of clones and plasmids in the spread of antimicrobial resistance and virulence. The E. coli virulence and antimicrobial resistance gene profiles of isolates will be screened following whole genome sequencing and a more complete clonal analysis by whole genome phylogenetic approaches.A novel aspect of this research is that we have first-hand models using a real situation in which bacterial virulence and multidrug resistance are coming together to create a crisis situation. This research will improve our knowledge of how high-risk clones can emerge, circulate, and contribute to increasing the spread of antimicrobial resistance. It will shed some light on how to «manage» production animals in order to reduce the spread of antimicrobial resistance to acceptable levels, allowing the continued judicious use of key antimicrobials and reducing the risk of transmission of antimicrobial resistance determinants to humans.