Antibiotic resistant bacteria and resistance genes in the bottom sediment of a small stream and the potential impact of remobilization

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

Abstract

River sediments are regarded as hot spots of bacterial density and activity. Moreover, high bacterial densities and biofilm formation are known to promote horizontal gene transfer, the latter playing a vital role in the spread of antimicrobial resistance. It can thus be hypothesized that sediments act as a reservoir of antibiotic resistant bacteria (ARB) and resistance genes (ARGs), particularly in rivers receiving microbes and drug residues from treated sewage. We analyzed the phenotypic susceptibility of 782 Escherichia coli isolates against 24 antimicrobials and we measured the relative abundances of five ARGs in water and sediment extracts of a small stream. We did not find evidence for a general increase in the proportion of resistant E. coli isolated from sediments as compared to those found in stream water. For most antimicrobials, the likelihood of detecting a resistant isolate was similar in water and sediment or it was even lower in the latter compartment. The mean relative abundance of ARGs was moderately increased in sediment-borne samples. Generally, absolute abundances of resistant cells and resistance genes in the sediment exceeded the pelagic level owing to higher bacterial densities. The river bottom thus represents a reservoir of ARB and ARGs that can be mobilized by resuspension.

Details

Original languageEnglish
Article number128
Number of pages11
JournalFEMS Microbiology Ecology
Volume94
Issue number9
Publication statusPublished - Sept 2018
Peer-reviewedYes

External IDs

Scopus 85050828195
ORCID /0000-0002-6048-6984/work/142240082

Keywords

Keywords

  • antibiotic resistance, Escherichia coli, river, sediment, remobilization, WATER TREATMENT-PLANT, ESCHERICHIA-COLI, FECAL BACTERIA, SURFACE-WATER, FLOOD EVENTS, RIVER, BIOFILMS, RESUSPENSION, STORMWATER, METABOLISM