Given that surfers and those who engage in similar ocean going activities have three times the levels of antimicrobial resistance bacteria compare with the general population, the new research gives pause for thought and suggests that the seas contain high populations of some dangerous species of bacteria.
According to lead scientist Anne Leonard, who is a research fellow at the European Centre for Environment and Human Health at the University of Exeter Medical School in Truro, England, the findings highlight do suggest a level of risk, even for those who healthy immune systems, who elect to participate in water sports. It is estimated that over 2.5 million water sports sessions occur in England and Wales in a given year.
Superbugs and the sea
She states: “When people think of superbugs and antibiotic resistant-bacteria, they think of the hospital. But there’s evidence that new resistant genes could be evolving in the environment and getting into people.”
The microbiologist expounded upon the importance of environmental controls: “Protecting our environment will have a multitude of benefits.”
The issue simply relates to the fact that surfers swallow more seawater than other swimmers, hence they have more antibiotic-resistant bacteria in their guts (the researchers were able to use previously published estimates on the volumes of water that people enjoying various water sports typically swallow). The big surprise is just how much more surfers are carrying.
Sampling fecal matter
For the study, the Leonard’s science team collected fecal samples from 273 volunteers. Of these, 143 people were self-declared frequent surfers or body-boarders. The volunteers were all drawn from U.K. and their water-sports activities were all undertaken in U.K. waters.
The analysis of these samples, using molecular sequencing methods, disclosed that surfers and body-boarders carried triple the rate of Escherichia coli bacteria; organisms that were resistant to the antibiotic cefotaxime (a class of a β-lactam antibiotic). Cefotaxime is commonly used to treat joint infections, pelvic inflammatory disease, meningitis, pneumonia, urinary tract infections, sepsis, gonorrhea, and cellulitis. The drug is given either by injection into a vein or muscle.
Resistant bacteria
Furthermore, the surfers and body-boarders were found to be four times more likely than others to carry types of E. coli that carried a gene (blaCTX-M) that makes other bacteria resistant to antibiotics. This gene can be exchanged between different bacteria, triggering acquired resistance.
The concern with gene transfer is that mobile resistance genes present in harmless commensal bacteria could be transferred to pathogenic strains, which then go on to cause infections which become difficult to treat with antimicrobial drugs.
While the risk is relatively low to healthy people, antibiotic-resistant E. coli can trigger gastrointestinal symptoms, as well as urinary-tract infections and meningitis. In terms of what actions should be taken, with surfers they should check the water quality of the sea before engaging in their activity. There are also certain activities that can increase the risk, such as surfing after heavy rain. This is because sewage and manure fertilizer are more likely to be washed from farms into waterways, and where water ways link to the sea.
Presenting the risk in terms of surfing, the supervising researcher Dr Will Gaze, explains: “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, wellbeing and connecting with nature. It is important that people understand the risks involved so that they can make informed decisions about their bathing and sporting habits.”
This said, the main actions should be directed to minimizing antibiotic use on farms where the drugs serve no real societal benefit (simply being used to create leaner meat) and pose a risk in terms of increasing resistance.
In terms of wider effects, the researchers note that the presence of antibiotic-resistant bacteria in coastal water is not confined to the U.K. Other research suggests a global problem. The current research has been reported to the journal Environment International, with the research paper headed “Exposure to and colonisation by antibiotic-resistant E. coli in UK coastal water users: Environmental surveillance, exposure assessment, and epidemiological study (Beach Bum Survey).”
Essential Science
This article is part of Digital Journal’s regular Essential Science columns. Each week Tim Sandle explores a topical and important scientific issue. Last week, we looked at the risks of a diet with too great a sodium content are well-documented. What has been less certain is whether a generally healthy diet can off-set consuming levels of sodium above recommended allowances. New research sheds light on this.
The week before we looked at one of the obstacles in place for a human led mission to Mars. Although space radiation presents one of the biggest challenges for a human journey to Mars, NASA is working on overcoming this, and other obstacles, so that humans sent to Mars on a future mission remain healthy.