• Travel spread antibiotic resistance
• Public health burden
What is already known on this topic
Antimicrobial resistance is one of the most serious public health threats, as treatment options for resistant bacteria are becoming increasingly limited. Scientists have known that international travelers can acquire antimicrobial-resistance genes and bring them back to their home countries, but the extent to which travel influences the spread of antibiotic resistance remains unclear.What this research adds
Researchers analyzed the gut microbiota of 190 Dutch adults before and after travel to regions where the prevalence of antimicrobial resistance is high. They found that, upon return, the travelers’ fecal samples had an increased number of antimicrobial-resistance genes, including some that confer resistance to common antibiotics as well as antimicrobials used when other drugs no longer work.Conclusion
The findings suggest that international travel poses a high risk to public health by favoring the global spread of antimicrobial resistance.
Antimicrobial resistance is one of the most serious public health threats, as treatment options for resistant bacteria are becoming increasingly limited. Now, researchers have found that international travelers may pick up bacteria containing genes conferring antimicrobial resistance and bring them back to their home country.
The findings, published in Genome Medicine, suggest that international travel poses a high risk to public health by favoring the global spread of antimicrobial resistance. “Even before the COVID-19 pandemic, we knew that international travel was contributing to the rapid global increase and spread of antimicrobial resistance,” says study co-first author Alaric D’Souza. “But what’s new here is that we’ve found numerous completely novel genes associated with antimicrobial resistance that suggest a worrisome problem on the horizon.”
Scientists have known that international travelers can acquire antimicrobial-resistance genes and bring them back to their home countries, but the extent to which travel influences the spread of antibiotic resistance remains unclear.
To address this question, Gautam Dantas at Washington University, John Penders at Maastricht University and their colleagues analyzed the gut microbiota of 190 Dutch adults before and after travel to Southeastern Asia, South Asia, North Africa, and Eastern Africa. All these regions have a high prevalence of antimicrobial resistance.
Travel spread antibiotic resistance
The researchers detected a total of 121 antimicrobial-resistance genes in the gut microbiota of international travelers, some of which had not been identified before. Upon return, the travelers’ fecal samples had an increased number of antimicrobial-resistance genes, including some that confer resistance to common antibiotics as well as antimicrobials used when other drugs no longer work.
The diversity of antimicrobial-resistance genes in the microbiota was also high in international travelers: the researchers found 56 different antimicrobial-resistance genes acquired during travel. This diversity was highest in individuals who came back from Southeastern Asia.
The analysis also showed that travelers acquired antimicrobial-resistance genes at their destinations. For example, a gene that confers resistance to colistin, which is used as a last-resort antibiotic to treat infections such as pneumonia and meningitis, was only found in individuals who traveled to Southeastern Asia.
Public health burden
The team found that fecal samples taken before travel also contained some antimicrobial-resistance genes, so one possibility is that the travelers spread resistance genes to the places they visited.
Understanding how antimicrobial-resistance genes disseminate globally could inform public health policies to prevent further spread, the researchers say. They note that in low- and middle-income countries, infections are increasingly resistant to a range of antibiotic drug treatments.
“It is vital that we address [antimicrobial resistance] in lower income countries with high resistance rates and low public health funds,” D’Souza says. “This global approach may not only help the respective countries, but it could also benefit others by reducing the international spread of resistance genes.”
