Prairie strips’ effect on transport of antimicrobial resistance indicators in poultry litter

Abstract

Poultry litter is a valuable nutrient resource for agricultural production but is also a potential source for introducing antibiotic resistance genes (ARGs) and litter‐associated bacteria (LAB) to the environment. Prairie strips have been demonstrated as an effective conservation practice to improve environmental quality in agroecosystems. This research aims to assess prairie strips’ potential for reducing the transport of LAB and ARGs in runoff after litter application. Plot‐scale rainfall simulations were performed using a replicated block design, with soil and surface runoff samples taken during the rainfall event. Microbial taxa and ARGs were characterized in the litter, soil, and water samples. In plots with litter application, LAB and ARGs were mainly detected in runoff, with very low detection in soils. Detection of ARGs in runoff, irrespective of strip installations, is consistent with previous observations of litter as a source of antimicrobial resistance (AMR) risks. The effectiveness of prairie strips to remove LAB and ARGs varied. In two of the three prairie strip plots, fewer AMR indicators were detected relative to control plots, suggesting that the prairie strips can potentially reduce these risks. In one plot, which was also associated with increased flow rate, we observed increased AMR indicators despite the installation of a prairie strip. Our observations highlight the need to prioritize understanding of soil properties even within the same site. Although we show that prairie strips can potentially reduce AMR risks, further research is needed to better understand the influence of rainfall timing, soil, and litter characteristics.

Comparison of antibiotic resistance genes in swine manure storage pits of Iowa, USA

“…To survey a broad range of genes, we also used a second method, which is a relative quantification method on a HT-qPCR platform. This method has recently been used by numerous studies (Muurinen et al, 2021;Fernanda et al, 2022;Flater et al, 2022;Kasuga et al, 2022;Mware et al, 2022;Samanta et al, 2022) because it allows for simultaneous presence/absence detection of numerous genes (Stedfeld). HT-qPCR is also limiting in the volume of each reaction (6.7 x 10 -3 mL vs 2 mL in conventional qPCR), which directly influences its detection limits.…”

Long-term impacts of conservation pasture management in manuresheds on system-level microbiome and antibiotic resistance genes

“…Overall, conservation pasture systems such as unfertilized edge-of-field grass buffer strips or fenced off riparian buffers can provide a wide range of environmental advantages, such as increased biodiversity, reduction in sediment erosion, and enhanced water quality ( Schulte et al, 2016 ; Anderson et al, 2020 ; Flater et al, 2022 ). These buffers were also an effective mitigation strategy for reducing ARGs entering surface waters by an order of magnitude, relative to continuously grazed manuresheds.…”

Plant and insect community responses to manure application in prairies

“…While improved manure collection, storage, and transportation technologies are being developed, incorporating vegetative buffer strips into the agricultural landscapes could provide an opportunity for waste disposal with a natural filter to decrease nutrient runoff. These vegetative buffers could be made up of native perennial plants thus providing wildlife habitat while addressing water quality concerns by trapping and absorbing excess nutrients and pollutants (Soil and Water Conservation Society, n.d.) and decreasing antimicrobial resistance risks associated with manure use (Alt et al 2023, Flater et al 2022.…”

“…applying manure to croplands or perennial plant communities located in and around crop fields could provide opportunities for incremental disposal while decreasing the typical environmental consequences associated with manure application. Prairie strips have been shown to help contain manure and its associated constituents within the agricultural environment, reducing pollution to nearby lakes and streams (Flater et al, 2022. Additionally, manure application could increase prairie biomass that could be used for livestock bedding or bioenergy production.…”