Correlation between upstream human activities and riverine antibiotic resistance genes

Area of Science:

• Environmental Science
• Microbiology
• Public Health

Background:

• Antimicrobial resistance (AMR) is a growing global health threat.
• The water environment is a potential pathway for the spread of antibiotic resistance genes (ARGs).
• Quantitative links between landscape features and ARGs in river systems remain poorly understood.

Purpose of the Study:

• To investigate correlations between ARGs and upstream anthropogenic sources in a river basin.
• To identify specific landscape features contributing to ARG dissemination via water pathways.

Main Methods:

• Quantitative polymerase chain reaction (qPCR) was used to measure sul1 and tet(W) ARGs in river sediments.
• A geospatial database mapped surface water pathways from potential sources (AFOs, WWTPs, hatcheries) to river monitoring points.
• General linear regression models were employed to assess correlations.

Main Results:

• Riverine sul1 gene abundance strongly correlated with upstream animal feeding operations (AFOs) and wastewater treatment plants (WWTPs).
• Distance-weighted correlations with AFOs significantly improved ARG association (R(2) = 0.60-0.64).
• The sul1 gene showed a high correlation (R(2) = 0.92) when averaged across sediments and sampling events, unlike tet(W).

Conclusions:

• Water pathways, particularly from AFOs, play a crucial role in the dissemination of specific ARGs like sul1.
• Understanding these waterborne ARG transmission routes is vital for mitigating AMR.
• Targeting water management strategies may offer effective control for ARG spread.