Hot spots of antibiotic tolerant and resistant bacterial subpopulations in natural freshwater biofilm communities due to inevitable urban drainage system overflows

Thomas Kaeseberg; Sara Schubert; Reinhard Oertel; Jin Zhang; Thomas U Berendonk; Peter Krebs

doi:10.1016/j.envpol.2018.06.081

Hot spots of antibiotic tolerant and resistant bacterial subpopulations in natural freshwater biofilm communities due to inevitable urban drainage system overflows

Environ Pollut. 2018 Nov;242(Pt A):164-170. doi: 10.1016/j.envpol.2018.06.081. Epub 2018 Jun 27.

Authors

Thomas Kaeseberg¹, Sara Schubert², Reinhard Oertel³, Jin Zhang⁴, Thomas U Berendonk⁵, Peter Krebs⁶

Affiliations

¹ Institute of Urban Water Management, Technische Universität Dresden, 01062 Dresden, Germany. Electronic address: thomas.kaeseberg@tu-dresden.de.
² Institute of Hydrobiology, Technische Universität Dresden, 01062 Dresden, Germany; Institute of Clinical Pharmacology, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, 01062 Dresden, Germany.
³ Institute of Clinical Pharmacology, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, 01062 Dresden, Germany.
⁴ Institute of Groundwater and Earth Sciences, Jinan University, 510632 Guangzhou, China. Electronic address: jin.zhang@hotmail.com.
⁵ Institute of Hydrobiology, Technische Universität Dresden, 01062 Dresden, Germany.
⁶ Institute of Urban Water Management, Technische Universität Dresden, 01062 Dresden, Germany.

PMID: 29980034
DOI: 10.1016/j.envpol.2018.06.081

Abstract

Antibiotic resistant bacteria are a threat to human life. Recently, sewers have been identified as potential reservoirs. The intermittent injection of sewage into adjacent surface waters is inevitable, due to capacity limitations of the urban drainage system. Information regarding the effect to natural freshwater biofilms (NFB) due to the intermittent contaminations are scarce. Therefore, a fundamental screening is necessary. In April, we placed NFB-attachment constructions in a brook upstream and downstream from urban drainage overflow constructions. In meanwhile two sampling campaigns were conducted. The sewage and the brook water were collected to gather information about antibiotic background exposure of ciprofloxacin (CIP), clarithromycin (CLA) and doxycycline (DOX). Six months later we experimentally determined the oxygen uptake rate (OUR) of the NFB-communities after a 24 h lasting exposure with additionally dosed antibiotics. Concentrations of 0.1, 1.0 and 10.0 mg L^-1 were selected. CIP, CLA and DOX were individually dosed, and also in mixtures. The mean antibiotic background concentration in sewage was in a range of 575.5-1289.1 ng L^-1, which mainly exceeded the concentrations published in literature. The determined mean concentration in the brook was in a range of 4.6-539.0 ng L^-1. The first significant inhibition of the OUR with individually dosed antibiotics started mainly at a concentration of 1.0 mg L^-1. Antibiotics in a mixture with concentrations of 0.1 and 1.0 mg L^-1 were as effective as single dosed antibiotics with a concentration of 10.0 mg L^-1. The increased antibiotic tolerance and resistance of NFB-communities downstream of the combined sewer overflow (CSO) structure was a consequence of a severe impact due to urban drainage overflows. Hence, NFB-communities downstream of CSO-constructions are hot spots of antibiotic tolerant and resistant subpopulations and access restrictions should be announced, if an infection risk is present.

Keywords: Antibiotics; Natural freshwater biofilm; Oxygen uptake rate; Resistance; Sewage; Sewer overflows; Surface water.

MeSH terms

Anti-Bacterial Agents / metabolism*
Bacteria / drug effects
Biofilms*
Ciprofloxacin / pharmacology
Drug Resistance, Microbial / genetics*
Environmental Monitoring*
Fresh Water
Sewage / chemistry
Water Microbiology*
Water Pollution / analysis*
Water Pollution / statistics & numerical data

Substances

Anti-Bacterial Agents
Sewage
Ciprofloxacin