Long time persistence and evolution of carbapenemase-producing Enterobacterales in the wastewater of a tertiary care hospital in Germany

Laura Carlsen; Henning Büttner; Martin Christner; Lukas Cordts; Gefion Franke; Armin Hoffmann; Birte Knobling; Marc Lütgehetmann; Jacqueline Nakel; Thomas Werner; Johannes K Knobloch

doi:10.1016/j.jiph.2023.05.029

Long time persistence and evolution of carbapenemase-producing Enterobacterales in the wastewater of a tertiary care hospital in Germany

J Infect Public Health. 2023 Aug;16(8):1142-1148. doi: 10.1016/j.jiph.2023.05.029. Epub 2023 May 26.

Affiliations

¹ Institute of Medical Microbiology, Virology, and Hygiene, Department for Infection Prevention and Control, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany.
² Institute of Medical Microbiology, Virology, and Hygiene, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany.
³ HAMBURG WASSER, Billhorner Deich 2, 20539 Hamburg, Germany.
⁴ Virus Genomics, Heinrich-Pette-Institute, Leibniz Institute for Experimental Biology, Martinistraße 52, 20251 Hamburg, Germany.
⁵ Institute of Medical Microbiology, Virology, and Hygiene, Department for Infection Prevention and Control, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany. Electronic address: j.knobloch@uke.de.

PMID: 37267681
DOI: 10.1016/j.jiph.2023.05.029

Abstract

Background: Worldwide observations revealed increased frequencies of multi-resistant Enterobacterales and resistance genes in hospital wastewater compared to any other type of wastewater. Despite the description of clonal lineages possibly adapted to hospital wastewater, little is known about long term persistence as well as evolution of these lineages.

Methods: In this study, wastewater isolates of different Enterobacterales species from a tertiary care hospital were investigated with 2.5 years distance. Whole Genome Sequencing (WGS) and resistance gene identification were performed for E. coli, C. freundii, S. marcescens, K. pneumoniae, K. oxytoca, and E. cloacae isolates (n = 59), isolated in 2022 and compared with strains isolated from the same wastewater pipeline in 2019 (n = 240).

Results: Individual clonal lineages with highly related isolates could be identified in all species identified more than once in 2022 that appear to persist in the wastewater drainage. A common motif of all persistent clonal lineages was the carriage of mobile genetic elements encoding carbapenemase genes with hints for horizontal gene transfer in persistent clones in this environment observed over the 2.5-year period. Multiple plasmid replicons could be detected in both years. In 2022 isolates bla_VIM-1 replaced bla_OXA-48 as the most common carbapenemase gene compared to 2019. Interestingly, despite a similar abundance of carbapenemase genes (>80% of all isolates) at both time points genes encoding extended spectrum β-lactamases decreased over time.

Conclusions: This data indicates that hospital wastewater continuously releases genes encoding carbapenemases to the urban wastewater system. The evolution of the resident clones as well as the reasons for the selection advantage in this specific ecological niche needs to be further investigated in the future.

Keywords: Antibiotic resistance; Carbapenemase; Enterobacterales; Hospital wastewater; Multi-resistant bacteria; Persistance.

MeSH terms

Anti-Bacterial Agents / pharmacology
Bacterial Proteins / genetics
Escherichia coli*
Humans
Klebsiella pneumoniae / genetics
Microbial Sensitivity Tests
Tertiary Care Centers
Wastewater*
beta-Lactamases / genetics

Substances

carbapenemase
Wastewater
Bacterial Proteins
beta-Lactamases
Anti-Bacterial Agents