Growing rates of antimicrobial-resistant bacteria are a major threat to public health. Recent research suggests that person-to-person transmission alone may not account for current levels of drug-resistant infections in the general public and that other sources such as the natural environment could be an important contributor.
Freshwater environments, such as rivers and lakes, naturally harbour diverse microbes but are also subject to human- and animal-associated bacteria and contaminants. For example, wastewater and agricultural runoff are strongly linked to increased levels of antimicrobial resistance in river bacteria.
The increasing popularity of recreational activities like wild swimming in UK rivers and lakes has raised concerns about people’s exposure to antibiotic-resistant bacteria. Although emerging evidence suggests a link between spending time in these environments and resistant infections, the research remains limited.
Led by PhD student Elitsa Penkova, this project is investigating the potential health risks of antimicrobial-resistant bacteria in rivers and lakes through three key studies.
A systematic review
First, we will conduct a systematic review to assess what is currently known about the presence, development, and transfer of resistant bacterial pathogens from freshwater environments across Europe, and quantify the extent of this risk in the UK.
The second strand of the research will use an online nationwide survey to gather new data on the general health implications of swimming in UK freshwaters. While there have been some reports of illnesses following river swims, we do not yet understand how significant or widespread these risks are. This study will collect data throughout the bathing season 2024 and compare the rates of illness between swimmers and non-swimmers.
The final component of this project will directly explore the links between recreational swimming in UK rivers and the presence of antibiotic-resistant bacteria in people’s intestinal tracts. With a focus on gut colonisation by cefotaxime-resistant Escherichia coli, or E. coli – commonly found in UK waters – we will test faecal samples from a range of people who either swim regularly or do not swim at all.
This study is also open and looking for participants – take part here >>
In addition to these data, we will also be targeting a specific group of swimmers who regularly visit the River Dart in Devon, UK. This target population will help improve our understanding of how colonisation with resistant bacteria occurs, is lost, or is maintained over time.
Furthermore, we will examine links between gut microbiome diversity, exposure to contaminated water, and colonisation by antibiotic-resistant microbes; and explore how the composition of swimmers’ intestinal microbiota is influenced by water exposure.
For information about each of these studies, please contact Elitsa Penkova.
The lead supervisor of this PhD is Dr Anne Leonard, it is co-supervised by Prof William Gaze, Prof Ruth Garside , Dr Andrew Singer (UK CEH), and Dr Nicola Elviss (UK HSA).