Distribution Of Mercury And Antibiotic Resistance Genes In Escherichia Coli From The Kahayan River, Central Kalimantan Under Heavy Metal Exposure

Abstract

The Kahayan River in Central Kalimantan, Indonesia, has been polluted by illicit gold mining, resulting in elevated levels of heavy metals, primarily mercury (Hg). The pollution jeopardizes the ecosystem and perhaps fosters bacterial antibiotic resistance. This study aimed to quantify heavy metal concentrations, especially mercury, in the river water and to assess antibiotic resistance in mercury-resistant E. coli. The antibiotic susceptibility was evaluated using the Vitek 2 Compact and PCR to detect resistance genes (merA, bla, gyrA, tet, catA) in E. coli isolates collected from upstream, midstream, and downstream river areas. The mercury concentrations were measured using an Atomic Absorption Spectrophotometer (AAS). The results indicated that E. coli isolates demonstrated various levels of resistance to antibiotics, especially Ciprofloxacin and Gentamicin. The gyrA gene, associated with quinolone resistance, was detected in samples from most areas. Meanwhile, the merA gene, related to mercury resistance, was discovered in samples taken from upstream, where mercury concentrations were maximal. In conclusion, this study demonstrates a relationship between antibiotic resistance in E. coli and mercury pollution. It highlights the importance of managing environmental contamination and prudent antibiotic use. Nevertheless, an investigation is necessary to evaluate the long-term effects of heavy metal exposure on antibiotic resistance in broader regions and to ascertain any causal relationships between these elements.