AMR concerns raised in major UK water source

Findings highlight human-driven catchment pressures and a need for stronger pollution control and AMR monitoring, experts say

Water samples from Lough Neagh, a freshwater lake which supplies drinking water for 40% of Northern Ireland, have found genes resistant to a wide range of antibiotics, including carbapenems, which are used to treat severe, multidrug-resistant bacterial infections.

The tests, undertaken by Watershed Investigations and the Guardian also found markers of human, cattle and pig faeces alongside the resistance genes. Lough Neagh is the largest lake in Ireland and the UK. 

The World Health Organisation (WHO) has described antimicrobial resistance (AMR) as “one of the most urgent, complex and frightening health challenges of our time”. It estimates that bacterial AMR contributes to around five million deaths per year. The misuse and overuse of antimicrobials in humans, animals and plants are blamed as the main drivers.

According to UK Health Security Agency (UKHSA) data, hundreds of resistant infections are reported each week in the UK, with deaths linked to them reaching an estimated 2,379 in 2024. 

Dr Daniel Read, Environmental Microbiologist at the UK Centre for Ecology and Hydrology (UKCEH) said the problem wasn’t new. “Prior research, including our own, has highlighted the presence of a wide range of AMR genes in freshwater environments, impacted by wastewater and agricultural inputs in England, so this finding is not specific to Lough Neagh.”

He added it was important to recognise that the presence of resistance genes “does not necessarily pose a health risk in treated drinking water or through direct exposure via recreational activities”.

Read said: “This is because the methods used in this analysis do not measure live microorganisms capable of causing infections. However, it does indicate systemic human-driven pressures on the catchment and potential environmental exposure routes, particularly through recreation or untreated water. 

“The priority now should be on reducing pollutant inputs, especially nutrients and faecal loads, while also enhancing catchment-scale monitoring of both pathogens and antimicrobial resistance to better evaluate risks and inform interventions.”

“It’s deplorable that a major water source is prone to toxic blue-green algal blooms and agricultural run-off with faecal contamination from livestock.” 

David Livermore, Professor Emeritus of Medical Microbiology at the University of East Anglia, said: “It’s deplorable that a major water source is prone to toxic blue-green algal blooms and agricultural run-off with faecal contamination from livestock. No reasonable person can defend such contamination. 

“I note multiple reports and press comments over the past few years on the algal blooms in particular; it seems likely that they are fed by the agricultural run-off.”

Livermore added that the most common carbapenemase in UK clinical bacteria is OXA-48, which occurs naturally in a water-living bacterial genus called Shewanella, carried on its chromosome. Shewanella is a genus very rarely found in infections. “However, there is the possibility it is concerningly resistant clinical bacteria that’s contaminated the Lough.” 

Andrew Muir, Minister of Agriculture, Environment and Rural Affairs in Northern Ireland, said he was aware of the evidence of AMR. He described it as “an urgent global challenge”. 

“A pilot study was conducted by my department in 2023, to investigate for evidence of AMR in Lough Neagh. Further research has since been commissioned and the results are due to report in April 2028."

Muir added, “These projects aim to determine the extent of AMR, those factors contributing to the AMR and associated risks posed to public and animal health. This will provide the scientific evidence to inform future policies and remedial action.

“The importance of restoring and protecting the ecological health of the Lough cannot be overstated and progress is being made.”