title: Abundance of antibiotics, antibiotic resistance genes and bacterial community composition in wastewater effluents from different Romanian hospitals.
abstract: Antimicrobial resistance represents a growing and significant public health threat, which requires a global response to develop effective strategies and mitigate the emergence and spread of this phenomenon in clinical and environmental settings. We investigated, therefore, the occurrence and abundance of several antibiotics and antibiotic resistance genes (ARGs), as well as bacterial community composition in wastewater effluents from different hospitals located in the Cluj County, Romania. Antibiotic concentrations ranged between 3.67 and 53.05 μg L-1, and the most abundant antibiotic classes were β-lactams, glycopeptides, and trimethoprim. Among the ARGs detected, 14 genes confer resistance to β-lactams, aminoglycosides, chloramphenicol, macrolide-lincosamide-streptogramin B (MLSB) antibiotics, sulfonamides, and tetracyclines. Genes encoding quaternary ammonium resistance and a transposon-related element were also detected. The sulI and qacEΔ1 genes, which confer resistance to sulfonamides and quaternary ammonium, had the highest relative abundance with values ranging from 5.33 × 10-2to 1.94 × 10-1and 1.94 × 10-2to 4.89 × 10-2copies/16 rRNA gene copies, respectively. The dominant phyla detected in the hospital wastewater samples were Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. Among selected hospitals, one of them applied an activated sludge and chlorine disinfection process before releasing the effluent to the municipal collector. This conventional wastewater treatment showed moderate removal efficiency of the studied pollutants, with a 55-81% decrease in antibiotic concentrations, 1-3 order of magnitude lower relative abundance of ARGs, but with a slight increase of some potentially pathogenic bacteria. Given this, hospital wastewaters (raw or treated) may contribute to the spread of these emerging pollutants in the receiving environments. To the best of our knowledge, this study quantified for the first time the abundance of antibiotics and ARGs in wastewater effluents from different Romanian hospitals.
authors.affiliation: NIRDBS, Institute of Biological Research, Cluj-Napoca, Romania; Molecular Biology and Biotechnology Department, Faculty of Biology and Geology, Babeş-Bolyai University, Cluj-Napoca, Romania.
authors.forename: Edina
authors.initials: E
authors.lastname: Szekeres
authors.affiliation: NIRDBS, Institute of Biological Research, Cluj-Napoca, Romania.
authors.forename: Andreea
authors.initials: A
authors.lastname: Baricz
authors.affiliation: NIRDBS, Institute of Biological Research, Cluj-Napoca, Romania; Molecular Biology and Biotechnology Department, Faculty of Biology and Geology, Babeş-Bolyai University, Cluj-Napoca, Romania.
authors.forename: Cecilia Maria
authors.initials: CM
authors.lastname: Chiriac
authors.affiliation: Molecular Biology and Biotechnology Department, Faculty of Biology and Geology, Babeş-Bolyai University, Cluj-Napoca, Romania.
authors.forename: Anca
authors.initials: A
authors.lastname: Farkas
authors.affiliation: National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj-Napoca, Romania.
authors.forename: Ocsana
authors.initials: O
authors.lastname: Opris
authors.affiliation: National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj-Napoca, Romania.
authors.forename: Maria-Loredana
authors.initials: ML
authors.lastname: Soran
authors.affiliation: Institute for Interdisciplinary Research in Bio-Nano-Sciences, Babeş-Bolyai University, Cluj-Napoca, Romania.
authors.forename: Adrian-Stefan
authors.initials: AS
authors.lastname: Andrei
authors.affiliation: Department of Chemistry, Biotechnology and Food Sciences, Norwegian University of Life Sciences, Aas, Norway.
authors.forename: Knut
authors.initials: K
authors.lastname: Rudi
authors.affiliation: Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, Girona, Spain.
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Balcázar
authors.affiliation: NIRDBS, Institute of Biological Research, Cluj-Napoca, Romania; Molecular Biology and Biotechnology Department, Faculty of Biology and Geology, Babeş-Bolyai University, Cluj-Napoca, Romania.
authors.forename: Nicolae
authors.initials: N
authors.lastname: Dragos
authors.affiliation: NIRDBS, Institute of Biological Research, Cluj-Napoca, Romania. Electronic address: cristian.coman@icbcluj.ro.
authors.forename: Cristian
authors.initials: C
authors.lastname: Coman
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis*; D001419:Bacteria / Q000187:drug effects; D004203:Disinfection; D004352:Drug Resistance, Microbial / Q000235:genetics*; D005798:Genes, Bacterial; D006761:Hospitals; D012383:Romania; D012722:Sewage / Q000382:microbiology; D013449:Sulfonamides; D013754:Tetracyclines; D014295:Trimethoprim; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology*; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D012722:Sewage; D013449:Sulfonamides; D013754:Tetracyclines; D014295:Trimethoprim; D062065:Wastewater; D014873:Water Pollutants
keywords: Antibiotic resistance genes; Antibiotics; Bacterial community composition; Hospital wastewater; Romania