Researchers in the United Kingdom have found that inappropriate use and widespread overprescribing of fluoroquinolone antibiotics, such as ciprofloxacin, have allowed drug-resistant Clostridium difficile pathogens to thrive. The researchers focused on an epidemic of severe diarrhea caused by C. difficile that hit British headlines in 2006.
The study, led by the University of Oxford, analyzed data on the numbers of C. difficile infections and on the amounts of antibiotics used in hospitals and by general practitioners in the U.K. More than 4,000 C. difficile microorganisms also underwent genetic analysis via whole-genome sequencing to determine the antibiotics to which each bug was resistant.
The researchers found that the restriction of fluoroquinolones resulted in the disappearance––in most cases––of infections caused by antibiotic-resistant C. difficile, leading to an 80% reduction in the number of these infections in the U.K. In contrast, the smaller number of cases caused by C. difficile bugs that were not resistant to fluoroquinolone antibiotics stayed the same.
At the same time, the number of bugs that were transmitted between people in hospitals did not change. This was despite the implementation of comprehensive infection prevention and control measures, such as better handwashing and hospital cleaning.
The findings were published in Lancet Infectious Diseases.
“Our study shows that the C. difficile epidemic was an unintended consequence of intensive use of an antibiotic class, fluoroquinolones, and that control was achieved by specifically reducing use of this antibiotic class, because only the C. difficile bugs that were resistant to fluoroquinolones went away,” said co-author Dr. Derrick Crook, professor of microbiology at the University of Oxford.
Co-author Dr. Mark Wilcox, professor of microbiology at the University of Leeds, added: “These findings are of international importance because other regions, such as North America, where fluoroquinolone prescribing remains unrestricted, still suffer from epidemic numbers of C. difficile infections.”
In their article, the authors state that antimicrobial stewardship should be a central component of C. difficile infection-control programs.