Die-off of E. coli as fecal indicator organism on different surfaces after urban floods

Iosif Marios Scoullos; Carlos M Lopez Vazquez; Jack van de Vossenberg; Damir Brdjanovic

doi:10.1016/j.jenvman.2019.109516

Die-off of E. coli as fecal indicator organism on different surfaces after urban floods

J Environ Manage. 2019 Nov 15:250:109516. doi: 10.1016/j.jenvman.2019.109516. Epub 2019 Sep 9.

Authors

Iosif Marios Scoullos¹, Carlos M Lopez Vazquez², Jack van de Vossenberg³, Damir Brdjanovic⁴

Affiliations

¹ Environmental Engineering & Water Technology Department, IHE Delft Institute for Water Education, P.O. Box 3015, 2601 DA, Delft, the Netherlands; Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ, Delft, the Netherlands. Electronic address: i.scoullos@un-ihe.org.
² Environmental Engineering & Water Technology Department, IHE Delft Institute for Water Education, P.O. Box 3015, 2601 DA, Delft, the Netherlands. Electronic address: c.lopezvazquez@un-ihe.org.
³ Environmental Engineering & Water Technology Department, IHE Delft Institute for Water Education, P.O. Box 3015, 2601 DA, Delft, the Netherlands. Electronic address: j.vandevossenberg@un-ihe.org.
⁴ Environmental Engineering & Water Technology Department, IHE Delft Institute for Water Education, P.O. Box 3015, 2601 DA, Delft, the Netherlands; Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ, Delft, the Netherlands. Electronic address: d.brdjanovic@un-ihe.org.

PMID: 31513998
DOI: 10.1016/j.jenvman.2019.109516

Abstract

A better understanding of the effects of different urban and recreational surfaces on the die-off of water-borne pathogens that can cause infections after urban floods if released from surcharged combined sewers and other sources of fecal contamination is needed. The die-off of fecal indicator Escherichia coli was studied under controlled exposure to simulated sunlight on a range of different surfaces found in urban environments: gravel, sand, asphalt, pavement blocks, concrete, playground rubber tiles and grass, using glass as control. The surfaces were inoculated with artificial flooding water containing 10⁵ colony forming units (CFU) of E. coli per mL and sampled periodically using the sterile cotton swab technique, after lowering the water level. The results show that dark inactivation was not statistically significant for any surface, suggesting that chemical composition and pH (varying between 6.5 ± 0.8 and 9.2 ± 0.4) did not affect the die-off rates. The highest light-induced die-off rates for E. coli after the floodwater recession, observed on rubber (>3.46 h^-1) and asphalt (2.7 h^-1), were attributed to temperature stress and loss of surface moisture.

Keywords: Solar inactivation; Surfaces; Urban floods; Water-borne diseases.

MeSH terms

Escherichia coli*
Feces
Floods*
Fresh Water
Water Microbiology