Composting of chicken litter from commercial broiler farms reduces the abundance of viable enteric bacteria, Firmicutes, and selected antibiotic resistance genes
Autor: | Jessica Subirats, Roger Murray, Andrew Scott, Calvin Ho-Fung Lau, Edward Topp |
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Rok vydání: | 2020 |
Předmět: |
Litter (animal)
Farms Environmental Engineering 010504 meteorology & atmospheric sciences Firmicutes Bacitracin 010501 environmental sciences Carnobacterium 01 natural sciences RNA Ribosomal 16S medicine Animals Environmental Chemistry Food science Psychrobacter Waste Management and Disposal 0105 earth and related environmental sciences biology Composting Broiler Drug Resistance Microbial biology.organism_classification 16S ribosomal RNA Pollution Anti-Bacterial Agents Gastrointestinal Microbiome Manure Microbial population biology Genes Bacterial Chickens medicine.drug |
Zdroj: | Science of The Total Environment. 746:141113 |
ISSN: | 0048-9697 |
DOI: | 10.1016/j.scitotenv.2020.141113 |
Popis: | We examined the ability of composting to remove ARGs and enteric bacteria in litter obtained from broiler chickens fed with a diet supplemented with Bacitracin methylene disalicylate (BDM) (conventional chicken litter), or an antibiotic-free diet (raised without antibiotic (RWA) chicken litter). This was done by evaluating the litter before and after composting for the abundance of ten gene targets associated with antibiotic resistance or horizontal gene transfer, the composition of the bacterial communities, and the abundance of viable enteric bacteria. The abundance of gene targets was determined by qPCR and the microbial community composition of chicken litter determined by 16S rRNA gene amplicon sequencing. Enteric bacteria were enumerated by viable plate count. A majority of the gene targets were more abundant in conventional than in RWA litter. In both litter types, the absolute abundance of all of the target genes decreased after composting except sul1, intI1, incW and erm(F) that remained stable. Composting significantly reduced the abundance of enteric bacteria, including those carrying antibiotic resistance. The major difference in bacterial community composition between conventional and RWA litter was due to members affiliated to the genus Pseudomonas, which were 28% more abundant in conventional than in RWA litter. Composting favoured the presence of thermophilic bacteria, such as those affiliated with the genus Truepera, but decreased the abundance of those bacterial genera associated with cold-adapted species, such as Carnobacterium, Psychrobacter and Oceanisphaera. The present study shows that chicken litter from broilers fed with a diet supplemented with antibiotic has an increased abundance of some ARGs, even after composting. However, we can conclude that fertilization with composted litter represents a reduced risk of transmission of antibiotic resistance genes and enteric bacteria of poultry origin to soil and crops than will fertilization with raw litter. |
Databáze: | OpenAIRE |
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