In the run up to the publication of the Government’s new UK antimicrobial resistance strategy, David Lloyd Owen, leading expert on water and wastewater management, explains why wastewater discharges are a key factor in the rise of antibiotic-resistant bacteria and how innovative technologies are best placed to tackle the problem.

Worldwide, antibiotic resistant bacteria are on the rise and discharges into wastewater systems are one of the main ways that resistance is spread, either via the dispersal of of antibiotic-resistant bacteria genes through effluent discharge or as a result of the development through natural processes of resistance to antibiotics discharged into water systems.

There is now growing urgency around the issue at international level - the problem was discussed by science ministers from across the G8 as part of the latest G8 summit which took place in Belfast in June. UK Minister for Universities and Science David Willets expressed his concern to his counterparts, commenting:

‘Across the G8, we should regard the spread of antibiotic resistance as a global challenge that is up there with climate change, water stress and environmental damage, and there are genuine policy consequences that follow from that.’

England’s Chief Medical Officer, Dame Sally Davies, has separately warned that untreatable infections pose a ‘catastrophic threat’ to the population. Among the recommendations in the Annual Report of the Chief Medical Officer, published in March this year, was a call for antimicrobial resistance to be put on the National Security Risk Assessment register and to be taken seriously by politicians at an international level, including the G8 and World Health Organisation. The Report states:

“Antimicrobial resistance is a ticking time bomb not only for the UK but also for the world. We need to work with everyone to ensure the apocalyptic scenario of widespread antimicrobial resistance does not become a reality. This is a threat arguably as important as climate change for the world.”

Effluent is primary source of antibiotic-resistant organisms

Antibiotic-resistant organisms enter water systems from human and animal sources, primarily via effluent. The bacteria are able to spread their genes into microbes that live in the water, which also contain resistance genes. Likewise, many manufactured antibiotics circulate in water environments via domestic sewage and hospital waste.

Tamiflu is contaminating rivers downstream of sewage-treatment facilities in Kyoto and levels are highest during the peak of the flu season. In the USA, 80% of antibiotics are used for livestock rearing - a primary cause of bacterial loading.

Despite its importance, the role of water in antibiotic resistance has however been overlooked until recently - a n issue consistently highlighted in a number of research studies which refer to “a remarkable paucity on data concerning the possible impacts of hospital discharges, direct or indirect, to the environment” and “a lack of information concerning the effects of these chemicals to critically assess potential risks for environmental discharge and water recycling.”

Conventional wastewater treatment cannot deal with either threat. For antibiotics, a range of approaches may be needed in order to remove a range of antibiotics with different chemical characteristics. Ozonation and electrochemical oxidation look the most promising ways forward here.

Despite the Duluth WWTW being one of the most advanced plants in the USA, when looking for genes of bacteria that would have superbug attributes, researchers found concentrations 20 times higher in the water released from the plant than in nearby waters. While much research has found what does not work and why for these types of bacteria, it looks like ultra violet light is the best way of eliminating bacterial material from effluent streams.

Ultra violet light is particularly effective when it hits directly i.e.where there is no ‘shadow’ from particulates behind which pathogens can hide. This means that pre-treatment is needed

With a specific focus on offering the most effective solutions available to address a range of challenges in the water environment, technology provider Bluewater Bio (BwB) believes that utilities and hospital facilities alike will increasingly look towards innovative technologies, used either as stand-alones or in combination, to address the issue.

Bluewater Bio’s FilterClear multimedia filtration technologies, added to its range of pre-treatment capabilities, coupled with NeoTech Aqua’s NeoTech UV treatment system, for which BwB has the UK and Ireland licence, is a case in point.

NeoTech is particularly effective on bacterial material as its chamber coating reflects over 99% of UV light compared with less than 30% in conventional devices. NeoTech also fits in with BwB’s philosophy of offering more for less, offering 5-10 times the disinfection performance of a conventional unit in terms of its size and energy use, needing 2-10% of the energy used while lowering lamp costs by 50-90%.

Keeping antibiotic resistant bacteria out of the wider environment is an urgent priority. It is a costly one as well. Applications such as BwB’s NeoTech have a role to play here, by making bacterial removal more effective and more affordable.

The Government is shortly due to publish its new UK antimicrobial resistance strategy and action plan – so it will be interesting to see whether it incorporates any guidance on how the presence of these antibiotic-resistant organisms in the water environment will be both monitored and dealt with.