The team found the first outbreak strain of C. difficile, FQR1 originated in the USA and spread across the country. They also saw sporadic cases of this strain of C. difficile in Switzerland and South Korea. They found that the second strain of C. difficile, FQR2, originated in Canada and spread rapidly over a much wider area, spreading throughout North America, Australia and Europe.
The team showed that the spread of C. difficile into the UK was frequently caused by long-range geographical transmission event and then spread extensively within the UK. They confirmed separate transmission events to Exeter, Ayrshire and Birmingham from North America and a transmission event from continental Europe to Maidstone. These events triggered large-scale C. difficile outbreaks in many hospitals across the UK in the mid-2000s.
"We have exposed the ease and rapidity with which these fluoroquinolone-resistant C. difficile strains have transmitted across the world," says Dr Trevor Lawley, lead author from the Wellcome Trust Sanger Institute. "Our research highlights how the global healthcare system is interconnected and how we all need to work together when an outbreak such as this occurs.
"Our study heralds a new era of forensic microbiology for the transmission tracking of this major global pathogen and will now help us understand at the genetic level how and why this pathogen has become so aggressive and transmissible worldwide. This research will act as a database for clinical researchers to track the genomic changes in C. difficile outbreaks."
|Contact: Aileen Sheehy|
Wellcome Trust Sanger Institute