Extended-Spectrum β-Lactamase and Carbapenemase Genes are Substantially and Sequentially Reduced during Conveyance and Treatment of Urban Sewage.
Liguan LiJoseph NesmeMarcos Quintela-BalujaSabela BalboaSyed HashshamMaggie R WilliamsZhuofeng YuSøren J SørensenDavid W GrahamJesús Ángel López RomaldeArnaud DechesneBarth F SmetsPublished in: Environmental science & technology (2021)
Urban wastewater systems (UWSs) are a main receptacle of excreted antibiotic resistance genes (ARGs) and their host microorganisms. However, we lack integrated and quantitative observations of the occurrence of ARGs in the UWS to characterize the sources and identify processes that contribute to their fate. We sampled the UWSs from three medium-size cities in Denmark, Spain, and the United Kingdom and quantified 70 clinically important extended-spectrum β-lactamase and carbapenemase genes along with the mobile genetic elements and microbial communities. Results from all three countries showed that sewage-especially from hospitals-carried substantial loads of ARGs (106-107 copies per person equivalent), but these loads progressively declined along sewers and through sewage treatment plants, resulting in minimal emissions (101-104 copies per person equivalent). Removal was primarily during sewage conveyance (65 ± 36%) rather than within sewage treatment (34 ± 23%). The extended-spectrum β-lactamase and carbapenemase genes were clustered in groups based on their persistence in the UWS compartments. The less-persistent groups were associated to putative host taxa (especially Enterobacteriaceae and Moraxellaceae), while the more persistent groups appeared horizontally transferred and correlated significantly with total cell numbers and mobile genetic elements. This documentation of a substantial ARG reduction during sewage conveyance provides opportunities for antibiotic resistance management and a caution for sewage-based antibiotic resistance surveillance.
Keyphrases
- drinking water
- antibiotic resistance genes
- wastewater treatment
- klebsiella pneumoniae
- microbial community
- anaerobic digestion
- gram negative
- multidrug resistant
- escherichia coli
- genome wide
- acinetobacter baumannii
- pseudomonas aeruginosa
- stem cells
- risk assessment
- combination therapy
- healthcare
- high resolution
- drug resistant
- dna methylation
- copy number
- gene expression
- genome wide identification
- cross sectional
- electronic health record
- urinary tract infection
- smoking cessation