Over 75% of Swiss tourists that visited India recently and were analysed by researchers, returned home with antibiotic-resistant bacteria in their guts. A strain of deadly bacteria resistant to the last active antibiotic was also identified.
The research carried out by scientists from the University of Bern, examined the stools of 38 Swiss travellers to India in 2015, before and after their trip. The results, published in the journal Antimicrobial Agents and Chemotherapy, were startling. Not only did 76% of those analysed have antibiotic resistant “superbugs” in their guts, 11% had bacteria that were resistant to the antibiotic colistin – the last line of defence in our antibiotic arsenal.
“The movement of people from countries with low antibiotic prevalence like Switzerland to high prevalence countries like India, creates a risk of importing superbugs,” Andreas Endimiani, one of the authors of the study, told swissinfo.ch. “The risk exists even if you take all precautions.”
The tourists tested, spent an average of 18 days in India. Around 40% suffered from diarrhea after returning from their holiday.
The colistin-resistant bacteria (E.coli) were found to spread through plasmids (small DNA fragments) that are independent of chromosomal replication. This means that they can transfer the colistin-resistance gene more easily to other bacteria in the gut.
“Colistin-resistant bacteria found in India are not well adapted to living in the gut and are eliminated in stools,” says Endimiani. “But in the meantime, they can transfer the colistin-resistant gene to your own gut bacteria that are already comfortable in your gut and stay with you forever.”
An unfortunate incident, like an accident or illness, can release these bacteria into bloodstream resulting in septic shock, which often results in death.
Despite the small sample of travellers tested, Endimiani is confident that around 75% of all tourists returning from India come back with antibiotic-resistant bacteria in their guts.
“Access to different antibiotics without prescription, overuse among population and their release into the environment creates a perfect storm for antibiotic resistance in the country,” he says.