Researchers at University of Galway have developed a new portable technology for on-the-spot testing of water quality for one of the most dangerous types of bacteria.
Ireland regularly reports the highest crude incidence rates of the pathogen Shiga toxigenic Escherichia coli - STEC for short - in Europe over the recent years.
The bacteria produces the harmful Shiga toxin, which, if ingested by humans, can cause severe stomach illnesses and, in some cases, life-threatening complications.
Children under five years, older people and immunocompromised individuals are particularly vulnerable to the toxin.
Work led by Dr Zina Alfahl, lecturer in bacteriology in the University’s college of medicine, nursing and health sciences, and Dr Louise O’Connor, senior research fellow with the University’s college of science and engineering, developed a technology for rapid, sensitive and accurate testing of STEC in water sources, including rivers, lakes and wells.
The results have been published in the journal, Microbiology.
“Our technology is a significant advancement in on-site water testing. It is portable, straightforward and safe to use. It is accurate, highly sensitive and the results are delivered quickly, on-site,” Dr Alfahl said.
“We are hoping that environmental health officers and groundwater schemes in Ireland could use the technology on-site allowing for more frequent testing especially in or after extreme weather, periods of intense rainfall, because it is those conditions which lead to water supplies being contaminated”Alfahl said.
STEC is normally found in the intestines of healthy animals like cows and sheep, which carry it without getting sick. The bacteria spreads to people through contact with animal waste, or by eating or drinking contaminated food or water.
A small sample of water can be tested on-site using isothermal amplification technology which can identify the genetic markers of STEC bacteria, and related E. coli.
The results are delivered in about 40 minutes through a reading on screen. Traditional lab testing of samples can take days for results to be returned.
The research, funded by Environment Protection Agency through the DERIVE project, tested samples from various water sources, including groundwater wells, rivers, a turlough and a farm drain on the Corrib catchment in Galway. Of the samples tested 61% were positive for the presence of this dangerous pathogen.
“This new testing method is particularly important for areas that rely on private groundwater wells, which can be more prone to contamination,” Dr O’Connor said.
“ In Ireland, a significant portion of the population depends on these for their drinking water - about 720,000 people, or one in every 5 households, but quality has been an issue as regulation is less stringent on these sources and testing is less frequent.”
