Location: Food Animal Environmental Systems ResearchTitle: Enrichments of antibiotic resistome following poultry litter soil amendment
|FANELLI, BRIAN - Cosmosid|
|Cook, Kimberly - Kim|
|HASAN, NUR - Cosmosid|
Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 9/16/2018
Publication Date: 12/4/2018
Citation: Agga, G.E., Fanelli, B., Looft, T.P., Cook, K.L., Durso, L.M., Hasan, N.A., Sistani, K.R. 2018. Enrichments of antibiotic resistome following poultry litter soil amendment. Research Workers in Animal Diseases Conference Proceedings. Poster No. 145.
Technical Abstract: Animal manure used for soil amendments can contain antibiotic resistant bacteria, antibiotic resistant genes (ARGs) and antibiotics. We evaluated the impact of poultry litter soil amendment on the occurrence of ARGs. A randomized complete block with a split plot arrangement of treatments, replicated four times, was used. Treatments included two winter cropping systems (fallow and cover crop) assigned to whole plots and three spring applied fertilizer treatments (unfertilized control (UC), poultry litter (PL), and synthetic commercial fertilizer (CF)) assigned to subplots. Four soil samples per fertilizer treatment were collected on d-7, d7, and d28 after fertilizer treatment application. Pooled (by fertilizer treatment and sampling day) metagenomic DNA samples (n=72) were analyzed by shotgun metagenomic sequencing and bioinformatics. Antibiotic resistome heat map showed higher number and diversity of ARGs in the PL amended soils compared to that of CF or UC soils, regardless of the cropping system. A similar trend was also observed for species alpha diversity (i.e., Chao1), with PL soil demonstrating highest species diversity. Increased propagation of the ARGs might, therefore, be a function of increased species diversity observed in the PL amended soils. From a community of 177 ARGs identified, 158 (89%) of them were detected from the PL amended soils compared to 34 (19%) in CF and 33 (18.6%) in UC soils. Over two-third of the top five most abundant ARGs, beta-lactamases, multidrug-efflux, aminoglycoside-, tetracycline-, and glycopeptide-resistance genes were detected from PL amended soils. Beta-lactamases, aminoglycoside-, macrolide-lincosamide-streptogramin-, sulfonamide- and tetracycline-resistance genes were detected in over half of the PL amended soils. The mean number of ARGs detected per sample increased from 4.5 on d-7 to 37.3 on d7, declining to 19.5 on d28 in the PL amended soils with no change in the CF and UC soils. In conclusion, soil amendment with stored poultry litter enriched the diversity of ARGs in the soil. Inorganic nutrients, provided through commercial fertilizer, and cropping system did not affect the occurrence of ARGs. Improved poultry litter management practices are required to reduce environmental dissemination of ARGs.