The study concluded that overuse of antibiotics like ciprofloxacin led to the outbreak of severe diarrhoea caused by C. difficile that hit headlines from 2006 onwards. The outbreak was stopped by substantially reducing use of ciprofloxacin and related antibiotics.
Inappropriate use and widespread over prescribing of fluoroquinolone antibiotics such as ciprofloxacin in fact allowed C. difficile bugs that were resistant to the drug to thrive, because non-resistant bugs in the gut were killed off by the antibiotic, leaving the way clear for rapid growth of resistant C. difficile.
Read more (Oxford University Hospitals NHS Foundation Trust website)