Felim Mc Tiernan

Comparison of molecular and traditional tools to evaluate the fate of enteric pathogens in two wastewater treatment plants in Co. Sligo and its environs

Supervisor: Dr. Michael Broaders, Dr. Michelle Connolly

Funding Body: Strand 1


The disposal of communities’ wastewaters throughout Ireland remains problematic, as inadequate infrastructure has failed to keep pace with housing developments, from major urban centres to rural communities and village developments. Public health issues, arising from disposal of untreated /inadequately treated sewage, have received increased attention following recent events in Co. Galway in relation to the outbreak of Cryptosporidiosis. Virtually no information exists on the pathogen loads discharged into the environment from the Wastewater Treatment (WWT) plants in Co. Sligo. In addition many of the WWT plants are old or overloaded and the effluents, having received inadequate treatment, are discharged into rivers, lakes, estuaries and onto beaches. Sludge disposal additionally generates its own list of environmental pollution issues.

This project aims to use modern molecular biology tools side by side with the use of the traditional bacterial indicators as a means of evaluating the extent of pathogen pollution arising from effluents discharged from two relatively large WWT plants in operation in Sligo and its environs. The project will compare the effectiveness of the WWT plants in relation to pathogen removal.

The use of molecular biology tools to monitor microbial pathogens in the environment will provide regulatory bodies with additional environmental information.

Techniques such as real-time polymerase chain reaction (RT-PCR), Fluorescent monoclonal antibody (mAb) staining in conjunction with dye inclusion/exclusion tests, and Fluorescent in-situ hybridisation (FISH) are to be used along with fluorescent microscopy and electrophoresis. These methods, used in parallel with traditional culture methods should yield data on pathogens such as Cryptosporidium, Giardia, Microsporidia, Norovirus, Escherichia coli, Clostridium perfringens & Enterococcus spp.

Any data of this nature is invaluable in assessing not only the effectiveness of current WWT technologies in pathogen removal, but also gives an indicator of the prevalence of such pathogens in the local population, and risks associated with the end products of the WWT process.


Giardia crypto Crypt_Giar