Catchment-scale processes contributing to transmission of antibiotic resistance in bathing waters

The ability of disease-causing bacteria to survive and grow in the presence of antibiotics designed to kill them (antibiotic resistance) has been described as one of the greatest threats to humans. This threat not only poses a risk to human health, but also to animal and plant health. It will have significant impacts on the economy through increased cost of treatment, longer hospital stays, and higher rates of morbidity and mortality. Increasing antibiotic resistance will also result in loss of economic productivity. In the World Bank's 2017 report on the devastating effect of drug-resistant infections on the global economy, they recommended that the key to tackling resistant infections should be to take action and make investments in the following sectors: Health, Agriculture, Urban Development, and Water and Sanitation. In this fellowship, I will conduct research, in collaboration with a representative of the Water and Sanitation Industry (South West Water), that will be relevant for many of these sectors. I aim to use cutting-edge technology to estimate the abundance of antibiotic resistant bacteria in bathing waters, which are impacted by various pollution sources (including those from wastewater treatment plants and agriculture). I will also investigate catchment-level processes which contribute to the transmission of antibiotic resistant bacteria to humans in these key environments. Bathing waters represent aquatic environments which many members of the public come into close contact with, leading to potential exposure to high levels of resistant bacteria. My previous research suggests that there are millions of human exposure events to one type of clinically important resistant Escherichia coli per year in UK bathing waters. The proposed research will focus on all resistance mechanisms in a key indicator bacterium, E. coli, which is quantified at all designated bathing beaches in the UK, allowing quantitative risk assessment of human exposure to be undertaken. By understanding the reasons for increased resistance and therefore increasing exposure risk, we can inform mitigation strategies for reducing microbial pollution.

The results of this research have global significance in terms of identifying and understanding the sources and transmission of antibiotic resistance. Not only will the findings be of academic interest but the information generated by the proposed research can help inform discussions about land and water management at both regional and national levels. In addition, the information generated by this research will contribute valuable knowledge to inform the water industry's response to the emerging problem of environmental antimicrobial resistance. Enhanced treatment methods are extremely costly and energy intensive, with consequences for society through higher water bills and greater greenhouse gas emissions. There is much public concern about these matters. Without sufficient evidence of the water industry's contribution to the problems and possible solutions, or of the degree of risk posed to human health, there is little incentive to devise and invest in innovative solutions to reduce the dissemination of antibiotic resistant bacteria to receiving waters.