Presentation of abstract: 1) oral
2) pitch Abstract title:
Tracking not conventional faecal pollution indicators in a Turin waste water treatment plant Deborah Traversi
Presenting author’s e-mail: deborah.traversi@unito.it Authors:
1 D Traversi, 2 V Romanazzi, 3 E Lorenzi, 4 G Gilli Affiliations:
1, 2, 4 Department of Public Health and Pediatrics, University of Torino, Torino, Italy;
3 SMAT – Depuratore di Castiglione Torinese, Società Metropolitana Acque Torino S.p.A., Torino, Italy
Abstract
Wastewater treatment plants (WWTPs) are an important source of surface water contamination by enteric pathogens. Moreover, they are a key point in the water cycle, affecting the role of environmental water as a microbial reservoir. This work was focused on not conventional faecal pollution biomarkers, and in particular on Methanobrevibacter smithii as a component of the human gut microbiome and on Clostridium difficile, a pathogen responsible for specific diseases that could no longer be considered restricted to hospital settings. The aim of the work is to track such biomarkers by bio-molecular methods in the waste water treatment plant effluents of Turin and describe their release into the environment.
20 water samples and 40 sludge samples, both influent and effluent, were firstly analysed by denaturing gradient gel electrophoresis (DGGE) for Bacteria and for Archaea. Moreover specific targets were evaluated by real-time quantitative polymerase chain reaction (qRT-PCR). In particular the quantification of total bacteria, total methanogens, Methanobrevibacter smithii, Clostridium spp. and Clostridium difficile were performed.
The DGGE analysis showed a greater variability for the Bacteria respect to the Archaea. All the chose specific targets were quantified by qRT-PCR in the collected samples. For all the microbial targets, the abatement was at least of 2 log comparing influent and effluent samples, with highly significant differences (p<0.0001). At the same time, there is evidence of microbial contamination of the effluent samples, this is
an important indication of their dissemination potential. The data give us also an indication on the diffusion of Methanobrevibacter smithii and Clostridium difficile at the environmental level.
These results open a discussion on the implementation of possible techniques for a more efficient microbial removal from WWTPs effluents both water and sludge, to avoid the uncontrolled release of pathogens into the environment.
Main messages:
Wastewater treatment plant is a critical control point for water-related diseases, not conventional faecal pollution biomarkers were detected in the water and sludge effluents by bio-molecular methods.
Methanobrevibacter smithii and Clostridium difficile can be considered not conventional faecal pollution indicators, they are present both in influent and effluent samples.
