Timeline

06-04-2020 - 06-04-2024

Group and collaboration

Collaboration: Prof. Dr. Jaap Wagenaar (Utrecht University), Dr. Aldert Zomer (Utrecht University), Dr. Ig. Egil Fischer (Utrecht University)

PhD Student: Aram Swinkels

Project description

The aims of this project are to determine the residual concentrations in faeces of broilers treated with antimicrobials and the longitudinal effect on antimicrobial resistance in commensal E. coli and on the microbiome in relation to the persistence of the antimicrobials, under experimental and field conditions. The antimicrobials which will be used are amoxicillin (non-persistent), doxycycline or enrofloxacin (persistent). In addition, the minimal selective concentration (MSC) will be determined for the selected antimicrobials. A mathematical model will then be used to investigate the effect of residual concentrations after treatment on the persistence of resistant bacteria. The model should incorporate the effect of antimicrobial residues on antimicrobial resistance selection and give indications about which type of antimicrobial and which concentration should be used to prevent selection for and spread of resistance.

Tasks

1. Collecting data under in vivo conditions, determining the level of residues and resistance over time, and identifying the optimal sample moments for fields experiments.
2. Measuring the selective concentrations of the antimicrobial compounds used in order to predict the selective effects of the residual antimicrobials in the environment on antimicrobial resistance development.
3. Using the data collected from the previous experiments, developing a mathematical model to study the association between dosing, residues and resistance.
4. Validating and optimising the model by determination of residues and resistance levels under field conditions after therapeutic treatment.