Detection of Antibiotic-Resistant Genes in Georgia Waterways Using eDNA Analysis

Bacteria have genetic material in the form of circular DNA, called plasmids. Regions of the plasmid may contain antibiotic resistant genes (ARGs) that allow bacteria to withstand antibiotics that would otherwise kill these bacteria. Increase of antibiotic-resistant bacteria (ARBs) in environmental waters represents a significant and growing public health threat. When ARGs enter water systems, they can contribute to the spread of infections that become difficult and costly to treat, leading to higher morbidity rates. The World Health Organization identified antimicrobial resistance as one of the top global health threats, showing urgency of learning, understanding and mitigating its environmental spread. Recent studies show the occurrence of eARGs in water from wastewater treatment plants and surface water can pose serious health risks due to increased virulence and transmission (Liang et. al 2021). Identification of bacteria with ARGs in wastewater treatment plants in other areas have raised concern as to whether these ARBs and ARGs are present in Georgia waterways. A previous study identified at least one antibiotic-resistance gene (the bla gene) from a local wastewater treatment plant that runs directly into Lake Lanier, a main drinking water source for the Atlanta area (Moua et. al 2024). In this study, the presence of bacteria has been successfully observed in Flat Creek, a stream near a water treatment facility using polymerase chain reactions (PCR) as the method of detection. Conduction of quantitative polymerase chain reactions (qPCR) will provide clearer results for the presence of the antibiotic-resistant gene, bla_CTX.