Microevolutionary analysis of Clostridium difficile genomes to investigate transmission

December 20, 2012

Over recent years, hospital-acquired Clostridium difficile infections have been a significant problem in UK hospitals and globally. There have been concerns that infections may be due to transmission between symptomatic patients, either directly, or indirectly via hospital staff; these concerns were strengthened when enhanced infection control was introduced in England in 2007, and the incidence of C. difficile infection declined. A recent study published in the open access journal Genome Biology, published by BioMed Central, took a genomics approach to assess the incidence of patient-to-patient transmission of C. difficile. The study was supported by the National Institute of Heath Research Oxford Biomedical Research Centre – a collaboration between Oxford University Hospitals NHS Trust and Oxford University.

The team, led by Tim Peto and Rosalind Harding at the University of Oxford, sequenced the genomes of C. difficile isolated from 486 patients treated at four hospitals in Oxfordshire between 2006 and 2010. By counting the number of between different isolates and estimating the of the bacteria, the researchers were able to determine the likely time at which any two isolates became genetically separate and thus, whether the two patients in question could have plausibly caught the infection from each other in the hospital. In other words, implies a time-scale that can be used for judging the likelihood of direct transmission.

The results of the study indicated that, although transmission between patients is likely to occur, it actually happens at relatively low frequency. In particular, concerns that healthcare teams were spreading infection between different hospitals seem to be misplaced. One exception to this general finding is that there were a large number of cases of infection from one particular strain that does appear to have been due to patient-to-patient transmission, emphasising the epidemic nature of this lineage. Notably, this strain has declined in UK hospitals in the last five years.

Dr Xavier Didelot, the study's lead author, said: " This research opens up very exciting opportunities for better understanding how bacterial infections are spread, and what we can do to stop them. The reduced cost of sequencing whole bacterial genomes means we now have the technology for identifying very recent transmissions of infection. Moreover, we can apply this technology even in cases when infection control teams have no suspicion that routes of contact between patients might exist".

Explore further: Transmission of Clostridium difficile in hospitals may not be through contact with infected patients

More information: Microevolutionary analysis of Clostridium difficile genomes to investigate transmission Xavier Didelot, David Eyre, Madeleine Cule, Camilla Ip, Azim Ansari, Dai Griffiths, Alison Vaughan, Lily O'Connor, Tanya Golubchik, Elizabeth Batty, Paolo Piazza, Daniel Wilson, Rory Bowden, Peter Donnelly, Kate Dingle, Mark Wilcox, Sarah Walker, Derrick Crook, Tim Peto and Rosalind Harding Genome Biology (in press)

Related Stories

Transmission of Clostridium difficile in hospitals may not be through contact with infected patients

February 7, 2012
Contrary to current convention by which infection with the organism Clostridium difficile is regarded as an infection that is acquired by contact with symptomatic patients known to be infected with C. difficile, these may ...

Study reports increasing incidence of Clostridium difficile infection

May 21, 2012
A study presented by Mayo Clinic researchers during Digestive Disease Week 2012 provides clear evidence that the number of people contracting the hard-to-control and treat bacterial infection Clostridium difficile (C. difficile ...

Outbreak C. difficile strain common in Chicago hospitals, investigation finds

August 11, 2011
An outbreak strain of Clostridium difficile, a bacterium that causes diarrhea and sometimes life-threatening inflammation of the colon, is common in Chicago-area acute care hospitals, an investigation published in the September ...

Bugs without borders: Researchers track the emergence and global spread of healthcare associated Clostridium difficile

December 9, 2012
Researchers show that the global epidemic of Clostridium difficile 027/NAP1/BI in the early to mid-2000s was caused by the spread of two different but highly related strains of the bacterium rather than one as was previously ...

C. difficile lengthens hospital stays by 6 days

December 5, 2011
A new study published in the CMAJ (Canadian Medical Association Journal) reports that hospital-acquired Clostridium difficile infection increases length of stay in hospital by an average of six days.

Recommended for you

Researchers developing new tool to distinguish between viral, bacterial infections

July 28, 2017
Antibiotics are lifesaving drugs, but overuse is leading to one of the world's most pressing health threats: antibiotic resistance. Researchers at the University of Rochester Medical Center are developing a tool to help physicians ...

Finish your antibiotics course? Maybe not, experts say

July 27, 2017
British disease experts on Thursday suggested doing away with the "incorrect" advice to always finish a course of antibiotics, saying the approach was fuelling the spread of drug resistance.

Co-infection with two common gut pathogens worsens malnutrition in mice

July 27, 2017
Two gut pathogens commonly found in malnourished children combine to worsen malnutrition and impair growth in laboratory mice, according to new research published in PLOS Pathogens.

Phase 3 trial confirms superiority of tocilizumab to steroids for giant cell arteritis

July 26, 2017
A phase 3 clinical trial has confirmed that regular treatment with tocilizumab, an inhibitor of interleukin-6, successfully reduced both symptoms of and the need for high-dose steroid treatment for giant cell arteritis, the ...

A large-scale 'germ trap' solution for hospitals

July 26, 2017
When an infectious airborne illness strikes, some hospitals use negative pressure rooms to isolate and treat patients. These rooms use ventilation controls to keep germ-filled air contained rather than letting it circulate ...

Researchers report new system to study chronic hepatitis B

July 25, 2017
Scientists from Princeton University's Department of Molecular Biology have successfully tested a cell-culture system that will allow researchers to perform laboratory-based studies of long-term hepatitis B virus (HBV) infections. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.