Degradation of plasmid-mediated resistance genes in poultry slaughterhouse wastewater employing a UV/H2O2 process: A metagenomic approach

• Published in: Chemosphere (Oxford) 2025-03, Vol.372, p.144109, Article 144109
• Main Authors: Oliveira de Farias, Beatriz, Saggioro, Enrico Mendes, Montenegro, Kaylanne S., Magaldi, Mariana, Oliveira Santos, Hugo Sérgio, Pimenta, Ramon Loureiro, Bianco, Kayo, Clementino, Maysa Mandetta
• Format: Article
• Language: English
• Subjects: Advanced oxidation processes; agricultural industry; antibiotic resistance; Antibiotic resistance genes; bacterial communities; beta-lactams; Burkholderiales; Escherichia coli; fluoroquinolones; metagenomics; Metaplasmidome; plasmids; poultry; slaughterhouses; wastewater; Wastewater treatment plant; Whole-genome sequencing
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2025.144109

Poultry slaughterhouse effluents are important hotspots for the spread of both antibiotic-resistant bacteria (ARBs) and antibiotic resistance genes (ARGs), contributing to the antimicrobial resistance (AMR). This study reports a novel investigation to assess the effects of UV/H2O2 treatment on the removal of metaplasmidome-mediated ARGs from poultry slaughterhouse effluents. The effluent samples were subjected at 0.005–0.15 mol L−1 of H2O2 and pH conditions (3, 5, 7 and 9). Bacterial community (rrs 16S rRNA), Escherichia coli (uidA) antimicrobial resistance (sul1 and int1) and metagenomic plasmid DNA removal were assessed. The UV/H2O2 treatment employing H2O2 = 0.01 mol L−1 at pH 3 resulted in decreased of several markers (uidA, sul1 and int1). A metaplasmidome indicated the persistence of Burkholderiales order. The UV/H2O2 process reduced plasmid-associated ARGs by 92.5% and 90.4% at pH 3 and 7, respectively. Persistent genes were mainly composed of genes associated with efflux pumps and resistance to beta-lactams and fluoroquinolones. These findings contribute to mitigate the spread of AMR in the agricultural sector, especially through the implementation of more efficient treatments, and reducing the use of antibiotics in livestock farming. [Display omitted] •The metaplasmidomes of UV/H2O2 treated slaughterhouse effluents were assessed.•A significant reduction in 16S rRNA was observed.•Plasmids associated with Burkholderiales still persisted after treatment.•Over 90% of plasmid-mediated ARGs were removed.•BlaOXA-570 and blaOXA-573 genes persisted after treatments.