Understanding worldwide C.difficile spread
C. difficile epidemics have emerged as a leading cause of worldwide antibiotic-associated diarrhoea (see Probiotics Learning Lab for more glossary terms) in the past ten years. The present study aimed to identify and track the genetic code of C. difficile strains taken from hospital patients, in order to better understand the patterns of worldwide spread and the rapid emergence of this bacteria. 151 samples of patients who died from or contracted C.diff between 1985 and 2012 were analysed, and the study involved specimens from 19 countries.
The research found that two specific antibiotic resistant C. difficile strains known as FQR1 and FQR2, which were first identified in North America, were responsible for hospital outbreaks as far away as the UK, Europe and Australia. FQR1 originated in the United States and was found to spread to Switzerland and South Korea, and FQR2 started in Canada and spread to North America, Europe, the UK and Australia.
Using genetic techniques, researchers were able to identify different strains and created a family tree for C.difficile which made it easier to trace the movements of this bacteria globally. They were also able to test another 145 samples from patients in Britain specifically, in order to more closely understand how the bacteria was able to spread once it arrived in the UK.
The analysis found that the strains became more severe and easily transmitted once the bacteria became resistant to antibiotics. The research also highlighted how interconnected global healthcare services are around the world and how rapidly strains of the bacteria were able to travel between countries.
Strains of C. diff are normally found in some human digestive systems and do not usually cause problems, although if patients which harbour an antibiotic resistant strain are given antibiotics, the bacteria may multiply and cause diarrhoea and sometimes serious disease which can lead to death.
This research will hopefully allow researchers in the future to more closely monitor and understand the spread of diseases such as those caused by C. diff, as well as work to limit the potential spread and outbreak of associated diseases.
You can find out about C. difficile and probiotics here.
Reference: Miao et al 2012, ‘Emergence and global spread of epidemic healthcare associated Clostridium difficile’. Nature Genetics, 9/12/12.