Antibiotic resistant bacteria in surfers guts

Conducted by the University of Exeter, the Beach Bums study asked 300 people, half of whom regularly surf the UK’s coastline, to take rectal swabs. Surfers swallow ten times more sea water than sea swimmers, and scientists wanted to find out if that made them more vulnerable to bacteria that pollute seawater, and whether those bacteria are resistant to an antibiotic. Scientists compared faecal samples from surfers and non-surfers to assess whether the surfers’ guts contained E. coli bacteria that were able to grow in the presence of cefotaxime, a commonly used and clinically important antibiotic. Cefotaxime has previously been prescribed to kill off these bacteria, but some have acquired genes that enable them to survive this treatment.

The study, published (January 14) in the journal Environment International, found that 13 of 143 (9%) of surfers were colonised by these resistant bacteria, compared to just four of 130 (3%) of non-surfers swabbed. That meant that the bacteria would continue to grow even if treated with cefotaxime.

Researchers also found that regular surfers were four times as likely to harbour bacteria that contain mobile genes that make bacteria resistant to the antibiotic. This is significant because the genes can be passed between bacteria – potentially spreading the ability to resist antibiotic treatment between bacteria. Recently, the UN Environment Assembly recognised the spread of antibiotic resistance in the environment as one of the world’s greatest emerging environmental concerns.

Dr Anne Leonard, of the University of Exeter Medical School, who led the research, said: “Antimicrobial resistance has been globally recognised 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. We urgently need to know more about how humans are exposed to these bacteria and how they colonise our guts. This research is the first of its kind to identify an association between surfing and gut colonisation by antibiotic resistant bacteria.”

Despite extensive operations to clean up coastal waters and beaches, bacteria which are potentially harmful to humans still enters the coastal environment through sewage and waste pollution from sources including water run-off from farm crops treated with manure. In the paper, the authors demonstrated the prevalence of cefotaxime-resistant E. coli in UK bathing waters as well as the prevalence of the mobile resistance gene that make bacteria cefotaxime resistant. They estimated that over 2.5 million water sports sessions occurred in England and Wales in 2015 which involved ingestion of E. coli bacteria harbouring these mobile resistance genes. They found that surfers are particularly vulnerable to ingesting the bacteria because they swallow up to ten times more water than sea swimmers. [...]

Full article at exeter.ac.uk

Full study, published in the journal Environment International DOI: 10.1016/j.envint.2017.11.003 here