The dynamic of antibiotic resistance in commensal Escherichia coli throughout the growing period in broiler chickens: fast-growing vs. slow-growing breeds

Abstract

Antimicrobial resistance (AMR) is an important threat to public health worldwide. Furthermore, different studies have demonstrated a close association between antibiotic use in animal production and AMR in humans. It is well known that it is necessary to reduce antibiotic administration in farms by finding effective alternative treatments, using more resistant breeds and improving animal welfare. However, to be able to assess the alternatives proposed, it is essential to study the epidemiology of AMR under production conditions. Hence, the aim of this study was to investigate the AMR dynamic in 2 genetic poultry breeds during the growing period. The study was performed in 2 experimental poultry houses to simulate real production conditions, and no antibiotics were administered during the growing period. In addition, 2 poultry breeds were used, fast-growing and slow-growing. To evaluate AMR evolution, Escherichia coli was selected as indicator bacterium. To this end, animals from each experimental group were sampled at different times: on day of arrival, at mid-period, and at slaughter day. In the laboratory, cecal content was removed and inoculated in selective media. Then, biochemical tests were performed to confirm E. coli . Finally, antibiotic susceptibility was assessed according to Decision 2013/653. At the onset of the cycle, significant differences were observed between breeds, as the E. coli strains isolated from fast-growing 1-day-old-chicks showed higher AMR rates. However, at the end of the period, no significant differences were found between breeds and their presence of resistant bacteria (above 95%). Therefore, although no antibiotics were administered during the growing period, a high level of AMR at slaughter day was demonstrated. Further studies are necessary to determine the main risk factors that increase the level of AMR throughout the productive cycle in broiler chickens. In conclusion, it is important to highlight that although it is crucial to control both antibiotic use and animal welfare during the growing period, measures should be taken at all levels of the production chain.

Fast and Slow-Growing Management Systems: Characterisation of Broiler Caecal Microbiota Development throughout the Growing Period

“…Moreover, due to the emergence of antimicrobial-resistant bacteria, society is pressing for a reduction in antibiotic administration by finding effective alternatives to control infectious diseases at farm level [ 12 , 13 , 14 , 15 ]. Some of these alternatives are feed additives (prebiotics, probiotics, symbiotics, organic acids, enzymes, phytogenics and metals), alternative medical treatments (antibacterial vaccines, immunomodulatory agents, antimicrobial peptides and bacteriophages) and, finally, different, less intensified broiler management systems [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ].…”

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“…Ante esta situación, nuestro grupo lleva 5 años estudiando la aplicación de bacteriófagos a nivel de campo, dentro de un proyecto CAMPYSALMO: del laboratorio a las aulas Europeo (H2020) y obteniendo resultados prometedores como herramienta alternativa al uso de antibióticos (Sevilla-Navarro et al, 2018;2020b). De la misma manera, hemos estudiado y analizado el impacto del bienestar animal sobre la microbiota intestinal del ave, así como sobre la adquisición y pérdida de multiresistencias a antibióticos, para lo cual se han utilizado herramientas de secuenciación genómica de última generación (Montoro-Dasi et al, 2020). Para poder llevar todo esto a cabo, hemos firmado numerosos convenios con empresas privadas del sector avícola, y también participado en proyectos con financiación pública autonómicos, nacionales y europeos, destacando el Proyecto Europeo dentro del Horizonte 2020 Nº 820523 "A cost-effective solution for controlling Salmonella and Escherichia coli in poultry production" (H2020-EIC-FTI-2018-2020).…”

Characterization of Sunflower Oil Extracts from the Lichen Usnea barbata

“…Among the most important MDR bacteria, the “ESKAPE” group encompassing Enterococcus faecium , Staphylococcus aureus , Klebsiella pneumoniae , Acinetobacter baumannii , Pseudomonas aeruginosa , and Enterobacter strains can escape the biocidal action of most antimicrobial agents [ 10 ]. In the poultry industry, a steadily increasing level of MDR bacteria has also been reported, for example of Escherichia coli [ 11 ], Campylobacter [ 12 , 13 , 14 ], Salmonella [ 15 , 16 ], and methicillin-resistant S. aureus (MRSA) [ 17 , 18 ].…”