One Health Resource Center

One Health Resource Center

January 16, 2018
3 min read

Surfers more likely to harbor antibiotic-resistant bacteria in gut

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Image of surfers
Study researcher Anne F.C. Leonard, PhD, MSc, interviews surfers on a beach in Cornwall, U.K.
Source: University of Exeter

Recent data showed that regular surfers and bodyboarders were nearly three times more likely to harbor antibiotic-resistant Escherichia coli in their guts compared with nonsurfers.

Anne F.C. Leonard, PhD, MSc, postdoctoral researcher at the University of Exeter Medical School, and colleagues reported in Environment International that their findings highlight the potential role of natural environments in the spread of antimicrobial resistance.

“Antimicrobial resistance has been globally recognized as one of the greatest health challenges of our time, and there is now an increasing focus on how resistance can be spread through our natural environments,” Leonard said in a press release. “We urgently need to know more about how humans are exposed to these bacteria and how they colonize our guts. This research is the first of its kind to identify an association between surfing and gut colonization by antibiotic-resistant bacteria.”

It is estimated that annual deaths attributable to drug-resistant infections could reach 10 million by 2050, according to the researchers. Resistance, they noted, can arise though a mutation or be acquired through resistance genes that are transferred by other bacteria via mobile genetic elements.

Leonard, along with William H. Gaze, PhD, associate professor at the University of Exeter Medical Center, and colleagues tested 97 bathing-associated waters in England and Wales to determine the prevalence of antibiotic-resistant bacteria and bacteria harboring mobile genes associated with antibiotic resistance. Of the sampled waters, 15 contained third-generation cephalosporin-resistant E. coli and 11 contained E. coli that harbor mobile genes. The overall percentage of E. coli harboring mobile genes was low, at 0.07%. However, the researchers said the levels were “high enough to pose an exposure risk to water users.”

The researchers then conducted a survey to determine the prevalence of antibiotic-resistant bacteria in surfers and bodyboarders, who ingest approximately 10 times more sea water than nonsurfers, according to the release. The analysis included rectal swabs from 143 surfers and 130 controls.

Results from the “Beach Bum Survey” showed that surfers were 2.95 (95% CI, 1.05-8.32) times more likely to harbor antibiotic-resistant E. coli (9.1% vs. 3.1%) and 4.09 (95% CI, 1.02-16.4) times more likely to harbor E. coli with mobile genes (6.3% vs. 1.5%) compared with nonsurfers. Leonard, Gaze and colleagues noted that gut bacteria are a major source of infection and their findings are of “public health significance.”

“We are not seeking to discourage people from spending time in the sea, an activity which has a lot of benefits in terms of exercise, well-being and connecting with nature,” Gaze said in the release. “It is important that people understand the risks involved so that they can make informed decisions about their bathing and sporting habits. We now hope that our results will help policymakers, beach managers, and water companies to make evidence-based decisions to improve water quality even further for the benefit of public health.” – by Stephanie Viguers


Disclosures: Gaze reports receiving grants from AstraZeneca, the Biotechnology and Biological Sciences Research Council, and the Medical Research Council for research outside of the submitted work. Please see the study for all other authors’ relevant financial disclosures.