Antimicrobial resistance (AMR) occurs when bacteria, viruses, fungi and parasites change over time and no longer respond to medicines, making infections harder to treat and increasing the risk of disease spread, severe illness and death. As a result of drug resistance, antibiotics and other antimicrobial medicines become ineffective, and infections become increasingly difficult or impossible to treat. Researchers estimated that AMR in bacteria caused an estimated 1.27 million human deaths worldwide in 2019.
Virginia Tech Launches AgroSeek
Metagenomics is gaining attention as a powerful tool for identifying how agricultural management practices influence human and animal health, especially in terms of potential to contribute to the spread of antibiotic resistance. However, it is impossible to compare the distribution and prevalence of antibiotic resistance genes (ARGs) across multiple studies and environments without a complete re-analysis of published datasets.
With support from NIFA, researchers at Virginia Tech created AgroSeek, a centralized, web-based system that provides tools for analysis and comparison of metagenomic data sets tailored specifically to researchers and other users in the agricultural sector interested in tracking and mitigating the spread of ARGs. AgroSeek draws from rich, user-provided metagenomic data and metadata to facilitate analysis, comparison and prediction in a user-friendly fashion. AgroSeek draws from public data sets to provide a point of comparison and context for data analysis.
This easy-to-use tool also creates a space for metagenomic data sharing and collaboration to assist policy makers, stakeholders and the public in decision-making.
University of Tennessee Scientists Develop Alternative to Antibiotics for Poultry
In 2017, the FDA phased out the use of in-feed medically important antibiotics for growth promotion in animal production in food animals. As a result of this FDA regulation, there was an immediate significant decrease of AMR bacteria in agriculture, with no change in AMR bacteria in humans. However, limiting antibiotics compromised production efficiency and animal health. Thus, developing effective alternatives to antibiotics was urgently needed.
University of Tennessee scientists have developed two types of innovative small molecules, namely bile salt hydrolase inhibitors and host defense peptide-inducing compounds, as alternatives to antibiotics for growth promotion and disease control in poultry. They then used innovative and cost-effective encapsulation technologies to further improve the effectiveness of these natural compounds for commercial applications.
As a result of this work, researchers discovered a strong synergy between butyrate and forskolin in enhancing innate immunity, barrier function and disease resistance without triggering inflammatory cytokine gene expression. They found a strong synergy among butyrate, forskolin and lactose in promoting innate immunity and disease resistance. They identified a strong synergy between butyrate and sugars in inducing host defense peptide gene expression. And they discovered a strong synergy between butyrate and cyclooxygenase-2 inhibitors to induce host defense peptide gene expression.
The researchers expect this project to lead to the development of two innovative non-antibiotic feeding technologies for immediate adoption and commercialization in poultry and possibly other livestock, thus mitigating AMR across the food chain.
Iowa State University Find Prairie Strips Reduce Manure Runoff
Elevated levels of resistant bacteria and resistance genes are finding their way into the environment through the land application of manure associated with animal production facilities. Prairie strips are a novel edge-of-field vegetative system, already demonstrated as a cost-effective strategy for substantially improving water quality in runoff from row-cropped agricultural watersheds, with minimal impacts on crop production.
The field application of swine manure can enrich the presence and abundance of manure-associated genes and bacteria within recipient soils and downstream runoff. However, scientists at Iowa State University found that the installation of prairie strips downslope from manured fields can significantly reduce the cumulative abundance of manure-associated genes in both runoff water and runoff sediment, thus mitigating the spread of antimicrobial resistance to the environment. As well, although manure associated bacteria were transported both horizontally, from the manure amended crop soil into the prairie strip soil, and vertically, into the crop and prairie strip soil profiles, these bacteria were also effectively reduced from both the runoff water and runoff sediment.
University of California Davis Develops Tool to Detect Antibiotics in Seafood
Approximately 80% to 90% of the seafood consumed in the United States is imported from Asia or South America where antibiotics are routinely used in aquaculture to optimize fish or shellfish growth. The routine use of antibiotics in aquaculture farms has been linked to antibiotic drug resistance in humans, which is why regulatory agencies mandate routine testing of seafood for antimicrobials, upon arrival to the United States.
To overcome the technological limitations of routine monitoring of imported seafood, University of California Davis scientists developed a new hand-held device that enables rapid isolation and detection of several antibiotics in seafood, using a mobile phone camera. Researchers expect this new tool will lead to notable and trackable improvements in food safety and public health by reducing the risk of antibiotic drug resistance from seafood imports. The technology also can potentially be adapted to probe other antibiotics and environmental chemicals in other food systems.
By enabling routine monitoring of antibiotic residues in seafood, U.S. scientists will gain a better understanding of the extent of residue contamination in imported seafood within the United States as well as better empower regulatory agencies and suppliers to ensure that uncontaminated seafood reaches consumers. Ultimately, this may help reduce the burden of antibiotic drug resistance contributed by seafood imports.
Top image: Researcher looking through a microscope. Courtesy of Adobe Stock.