Scientists make case for year-round water tests

The study, published by scientists from the university’s Ryan Institute, tested 118 bathing water and 36 sewage samples at locations around the country from July 2019 until November 2020.

ESBLP (Extended-spectrum beta-lactamase-producers), a type of enzyme produced by germs that makes infections harder to treat with antibiotics, were in 78% of the water samples collected and 50% of the sewage samples.

At 23 of the sampling sites, CPE (carbapenemase-producing Enterobacterales), bacteria that are resistant to most types of antibiotics, were found.

According to the study, the majority of CPE detected came from water samples collected in Galway City and Cork.

However, the detection of CPE was more consistent in the samples from Galway City over different seasons.

“This is a very major problem,” said Professor Dearbháile Morris, Director of the Centre for One Health in Ryan Institute at NUI Galway.

“We do need to try and stem the spread, particularly of the CPE.”

However, Prof Morris said that the detection of CPE in Galway does not suggest there is a bigger issue in Galway than in other places in Ireland.

She said that the team collected more samples from the Galway area than anywhere else, and it would be “highly likely” for there to be similar results in other areas.

Prof Morris also said that there is “good control” of antibiotic-resistant bacteria in Ireland, but it is still a concern in other parts of the world.

“Other parts of the world have very significant problems with those organisms, and unfortunately some of them are so resistant, they’re resistant to pretty much all of the antibiotics we have available to treat infection,” she said.

Another project led by Prof Morris, known as PIER, will investigate if exposure to antibiotic-resistant bacteria in recreational waters affects people’s health.

The project is funded by the Environmental Protection Agency and began in March of 2019 and is expected to last four years.

“What we're trying to understand better is if these antibiotic-resistant organisms are in waters where people are swimming, surfing, or carrying out other water activities with, is there a difference between the people that use those waters a lot in terms of them potentially swallowing these organisms and then becoming resident to their gut compared to those that don't maybe use the waters a lot,” said Prof Morris.

Ireland follows the EU Bathing Water Directive, meaning that waters are only tested during the bathing season of June 1 until September 15 each year.

Prof Morris said that these criteria raise numerous issues – not least the fact that people swim throughout the year in Ireland, and that the sample of water required for testing it too small and does not test for the correct things.

At the moment, testing is done on 100ml samples collected from an initial sample of one litre. The testing only looks at the total number of E. coli in the sample, which is an indication that there could be faecal contamination. Prof Morris said this type of testing does not reveal anything about the bacteria.

“There's lots of different types of E. coli, some are totally benign, they're not going to have any impact on you, but if it's an antibiotic-resistant E. coli or toxigenic E. coli, then that's a very different situation.

“The regulations should be revised to look at the characteristics of the organism to determine whether or not it is an antibiotic-resistant E. coli, or other sorts of E. coli that may be of public health concern. If they were changed, the routine monitoring for antibiotic-resistant E. coli in the environment would further the evidence and understanding of the actual role of the environment in the persistence and transmission of antibiotic resistance,” she said.

She said it is not only up to doctors and scientists to do something about antibiotic resistance, and that awareness is an important part of helping prevent the problem from getting worse.

Taking a full course of antibiotics even if you’re feeling better and discarding of antibiotics properly at a pharmacy are all small actions that can help prevent antibiotic resistance from getting worse.

“There's lots everybody can do to try and slow down the problem that we have. We don't want to panic anybody, but it is a huge problem. It's not something that's happening in the future, it’s actually happening now,” said Prof Morris.

(Photo: Professor Dearbháile Morris of NUI Galway says antibiotic-resistant bacteria in waters has become a major problem).