Occurrence of Antibiotic-Resistant Genes and Bacteria in Household Greywater Treated in Constructed Wetlands

Michelle Henderson, Sarina J. Ergas, Kebreab Ghebremichael, Amit Gross, Zeev Ronen

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


There is a growing body of knowledge on the persistence of antibiotic-resistant genes (ARGs) and antibiotic-resistant bacteria (ARB) in greywater and greywater treatment systems such as constructed wetlands (CWs). Our research quantified ARGs (sul1, qnrS, and blaCTXM32), class one integron (intI1), and bacterial marker (16S) in four recirculating vertical flow CWs in a small community in the Negev desert, Israel, using quantitative polymerase chain reaction (qPCR). The greywater microbial community was characterized using 16S rRNA amplicon sequencing. Results show that CWs can reduce ARG in greywater by 1–3 log, depending on the gene and the quality of the raw greywater. Community sequencing results showed that the bacterial community composi-tion was not significantly altered after treatment and that Proteobacteria, Epsilonbacteraeota, and Bacteroidetes were the most dominant phyla before and after treatment. Pseudomonas, Citrobacter, Enterobacter, and Aeromonas were the most commonly identified genera of the extended spectrum beta lactamase (ESBL) colonies. Some of the ESBL bacteria identified have been linked to clinical infections (Acinetobacter nosocomialis, Pseudomonas fulva, Pseudomonas putida, Pseudomonas monteilii, and Roseomonas cervicalis). It is important to monitor intI1 for the potential transfer of ARGs to pathogenic bacteria.

Original languageEnglish
Article number758
JournalWater (Switzerland)
Issue number5
StatePublished - 1 Mar 2022


  • Antibiotic resistance
  • Constructed wetlands
  • Extended spectrum beta lactamase
  • Greywater
  • Greywater treatment systems

ASJC Scopus subject areas

  • Water Science and Technology
  • Geography, Planning and Development
  • Aquatic Science
  • Biochemistry


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