Investigating the antibiotic resistance genes and mobile genetic elements in water systems impacted with...

A wide range of pollutants, including heavy metals, endocrine-disrupting chemicals (EDCs), residual pesticides, and pharmaceuticals, are present in various water systems, many of which strongly drive the proliferation and dissemination of antimicrobial resistance genes (ARGs), heightening the antimicrobial resistance (AMR) crisis and creating a critical challenge for environmental and health management worldwide. This study addresses the impact of anthropogenic pollutants on AMR through an extensive analysis of ARGs and mobile genetic elements (MGEs) in urban wastewater, source water, and drinking water supplies in India. Results indicated that bla_TEM and bla_CTXM-32 were the dominant ARGs across all water systems, underscoring the prevalence and dominance of resistance against β-lactam antibiotics. Moreover, transposase genes such as tnpA-02, tnp-04, and tnpA-05 were detected across all water systems, indicating potential mechanisms for genetic transfer. The ubiquitous presence of intI-1 and clin-intI-1 genes underscores the widespread dissemination of MGEs, posing challenges for water quality management. Besides, human pathogenic bacteria such as Clostridium, Acinetobacter, and Legionella were also detected, highlighting potential health risks associated with contaminated water. The identified pathogenic bacterial genera belong to the phyla Pseudomonadota and Firmicutes. Leveraging linear regression to analyze correlations between EDCs and ARG-MGEs provides deeper insights into their interconnected dynamics. DMP showed a significant influence on tnpA-02 (p = 0.005), tnpA-07 (p = 0.015), sul-1 (p = 0.008), intI-1 (p = 0.03), and clin-intI1 (p = 0.012), while DiNOP demonstrated a very high impact on tnpA-05 (p = 0). Redundancy analysis revealed significant correlations between resistance genes and EDCs. Additionally, environmental parameters such as pH were highly correlated with the majority of MGEs and bla_CTXM-32. Furthermore, we found that F^-, NO^-3, and SO₄^-2 were significantly correlated with sul-1, with F^- exhibiting the highest impact, emphasizing the intricate interplay of pollutants in driving AMR. Understanding these interconnected factors is crucial for developing effective strategies and sustainable solutions to combat antibiotic resistance in environmental settings.