Commensal Escherichia coli Antimicrobial Resistance and Multidrug-Resistance Dynamics during Broiler Growing Period: Commercial vs. Improved Farm Conditions
Autor
Montoro-Dasí, Laura; Villagra, Arantxa; Sevilla-Navarro, Sandra; Pérez-Gracia, María T.; Vega, Santiago; Marín, ClaraFecha
2021Cita bibliográfica
Montoro-Dasi, L., Villagra, A., Sevilla-Navarro, S., Pérez-Gracia, M. T., Vega, S., & Marin, C. (2021). Commensal Escherichia coli Antimicrobial Resistance and Multidrug-Resistance Dynamics during Broiler Growing Period: Commercial vs. Improved Farm Conditions. Animals, 11(4), 1005.Resumen
New measures applied to reduce antimicrobial resistances (AMR) at field level in broiler
production are focused on improving animals’ welfare and resilience. However, it is necessary to
have better knowledge of AMR epidemiology. Thus, the aim of this study was to evaluate AMR and
multidrug resistance (MDR) dynamics during the rearing of broilers under commercial (33 kg/m2
density and max. 20 ppm ammonia) and improved (17 kg/m2 density and max. 10 ppm ammonia)
farm conditions. Day-old chicks were housed in two poultry houses (commercial vs. improved),
and no antimicrobial agents were administered at any point. Animals were sampled at arrival day,
mid-period and at slaughter day. High AMR rates were observed throughout rearing. No statistical
differences were observed between groups. Moreover, both groups presented high MDR at slaughter
day. These results could be explained by vertical or horizontal resistance acquisition. In conclusion,
AMR and MDR are present throughout rearing. Moreover, although a lower level of MDR was
observed at mid-period in animals reared under less intensive conditions, no differences were found
at the end. In order to reduce the presence of AMR bacteria in poultry, further studies are needed to
better understand AMR acquisition and prevalence in differing broiler growing conditions.