Water (Sep 2023)

Risks of Antibiotic Resistance Dissemination by Leachates from Municipal Landfills of Different Ages

  • Māra Blumfelde,
  • Dita Gudrā,
  • Dzintars Začs,
  • Kārlis Vonda,
  • Laura Žorža,
  • Tūrs Selga,
  • Andrejs Grīnbergs,
  • Aija Dēliņa,
  • Vadims Bartkevičs,
  • Dāvids Fridmanis,
  • Olga Muter

DOI
https://doi.org/10.3390/w15193349
Journal volume & issue
Vol. 15, no. 19
p. 3349

Abstract

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Landfill leachate is regarded as a significant point source of pollutants that may pose a hazard to the environment, particularly to surface and ground waters. Leachates are highly variable and heterogeneous. Our study was focused on the characterization of landfill leachates derived from young (YDS) and matured (MDS) dumpsites in terms of the abundance of micropollutants, antimicrobial resistance genes (ARG), and microbial community structure. The concentrations of poly- and perfluoroalkyl substances (PFASs) were found to be higher in MDS compared to YDS, i.e., 13.19 and 7.16 μg/L, respectively. Among pharmaceutical compounds, ibuprofen was detected at the highest concentrations, i.e., 12.54, 12.81, and 13.13 μg/L, in the leachates derived from MDS, YDS, and ponds. The distribution of bacteria, archaea, eukaryotes, and viruses in the three leachate samples was as follows: 85.15 ÷ 88.04%, 9.13 ÷ 12.29%, 2.20 ÷ 2.68%, and 0.12 ÷ 0.15%, respectively. In total, 31 distinct families of ARGs were identified, comprising a total of 80 ARGs. Incubation of P. putida MSCL650 in sterile leachate from the pond resulted in decreasing the minimum inhibitory concentrations for six antibiotics as compared to cells incubated in nutrient broth. Hydrological processes, i.e., runoff and infiltration, can increase the dissemination of ARGs.

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