The natural hot springs in Bath that give the city its name and 2,000-year-old reputation for healing contain a small army of pathogen-combating bacteria. Biomedical researchers at the University of Plymouth sampled the water, sediment and bacterial biofilm from the King’s Spring and the Great Bath, and found 300 different types of bacteria, 15 of them showed broad spectrum activity against pathogens including E. coli, Staphylococcus aureus and Shigella flexneri.
Antimicrobial resistance is one of the most urgent threats to global health today. Antibiotic-resistant pathogenic infections were responsible for killing 1.27 million people around the world in 2019. That figure is expected to skyrocket to 10 million a year by 2050. There are no new antibiotics coming down the research pipeline, so the search for novel antimicrobial natural products is of towering importance in combating this threat. Extreme ecological environments are getting new attention as their unique ecosystems are rich in microbial diversity and may contain antimicrobial NP.
Bath’s hot springs are the only ones in the UK, and with the geothermal energy that heats the waters as high as 96 °C (205°F), it offers a unique opportunity for the discovery of microbial powerhouses. Thermal springs in Italy, India and Jordan have all been found to contain microbes that combat human pathogens, but this is the first study to look at Bath’s hot springs.
The mineral-rich hot springs of Bath have been famed for their medicinal properties since the pre-Roman Iron Age. The Britons built a shrine to the goddess Sulis at the site of the hot springs and when the Romans came, they built it up into a huge bath complex and temple dedicated to the goddess Minerva who they identified with the local deity Sulis. Even after the Romans left and the baths fell into ruin, new facilities were built several times from the Middle Ages into the 19th century.
The Roman Baths has been welcoming visitors for almost two millennia, and in 2023 more than one million people toured its hot springs and other collections.
Zofia Matyjaszkiewicz, Collections Manager at the Roman Baths and a co-author of the new study, added: “People have visited the springs in Bath for thousands of years, worshipping at, bathing in and drinking the waters over the centuries. Even in the Victorian period the Spa Treatment Centre in Bath used the natural spring waters for their perceived curative properties in all sorts of showers, baths and treatments. It’s really exciting to see cutting edge scientific research like this taking place here, on a site with so many stories to tell.”
The research into Bath’s potential contribution to the fight against antimicrobial resistance will continue. The University of Plymouth will launch an expanded study with a PhD studentship beginning October 2024 that will take an in-depth look at the Bath hot spring’s microorganisms, screening them to identify any with antimicrobial activity that may have clinical use.