Geospatial Patterns of Antimicrobial Resistance Genes in the US EPA National Rivers and Streams Assessment Survey

Abstract

Antimicrobial resistance (AR) is a serious global problem due to the overuse of antimicrobials in human, animal, and agriculture sectors. There is intense research to control the dissemination of AR, but little is known regarding the environmental drivers influencing its spread. Although AR genes (ARGs) are detected in many different environments, the risk associated with the spread of these genes to microbial pathogens is unknown. Recreational microbial exposure risks are likely to be greater in water bodies receiving discharge from human and animal waste in comparison to less disturbed aquatic environments. Given this scenario, research practitioners are encouraged to consider an ecological context to assess the effect of environmental ARGs on public health. Here, we use a stratified, probabilistic survey of nearly 2000 sites to determine national patterns of the anthropogenic indicator class I integron Integrase gene (intI1) and several ARGs in 1.2 million kilometers of United States (US) rivers and streams. Gene concentrations were greater in eastern than in western regions and in rivers and streams in poor condition. These first of their kind findings on the national distribution of intI1 and ARGs provide new information to aid risk assessment and implement mitigation strategies to protect public health.

Microbial source tracking and land use associations for antibiotic resistance genes in private wells influenced by human and livestock fecal sources

“…Importantly, human and bovine fecal contamination of these wells was associated with estimates of significant health risk (Burch et al, 2021). Therefore, while intI1 may indicate abundant fecal contamination or aggregated fecal influence (Beattie et al, 2018;Bourdonnais et al, 2022;Kampouris et al, 2021;Keely et al, 2022;Lee et al, 2021), our results suggest that it may not accurately predict contamination in all settings, like rural areas with dispersed septic systems and variable manure inputs.…”

Tracking Sources and Dissemination of Indicator Antibiotic Resistance Genes at a Watershed Scale

“…A similar pattern was observed at the sites with acid mine drainage impacts (sites 1, 2, and 5), where sul1 and mexE were detected without MST markers. One possible explanation for the persistent detection of ARGs is the potential role of 27,61 Researchers found that ARGs had an increased potential for mobility in samples collected downstream of wastewater discharges relative to upstream, supporting the elevated potential for the transfer of ARGs in a similar environment. 3) and statistical relationships (e.g., the significant and positive correlation between FIB E. coli and anthropogenic ARGs) (Figure 4) suggest that E. coli contamination could be useful for predicting ARGs in surface water.…”

Toward a Universal Unit for Quantification of Antibiotic Resistance Genes in Environmental Samples

“…To complement the surveys in human and animal sectors under the “One-Health” framework, surveillance has been increasingly conducted in environmental sectors, including manure, − soil, freshwater, , marine water, and wastewater treatment plants. − Conventional cultivation-based methods for characterizing ARB provide comprehensive information in terms of ARB phylogeny, resistance phenotype, and transferability of the resistance determinants. However, cultivation is highly exhaustive, and frequently only a small fraction of environmental bacteria can be cultivated.…”