Ribotyping on Clostridium difficile isolates from patients with Clostridium difficile infection allows for the identification of certain strains such as 027 that can be difficult to control when causing outbreaks and/or may be associated with poor clinical outcome.
Changes in the gut flora associated with broad spectrum antibiotics and chemotherapeutic agents can result in colonisation by C. difficile; it is the commonest identifiable cause of antibiotic associated diarrhoea (ADD). Almost all drugs with an antibacterial spectrum of activity have been implicated causally in AAD. The most frequently implicated drugs are those which have a marked effect on the microflora of the colon. These include broad spectrum beta lactams, cephalosporins, clindamycin and fluoroquinolones. The incidence of C. difficile infection has been shown to decrease once antibiotic therapy is controlled.
The production of two toxins A (enterotoxin) and B (cytotoxin) causes the characteristic mucosal damage consisting of plaque-like lesions leading to the formation of a pseudomembrane. Not all strains of C. difficile produce toxin, and therefore not all can cause illness. The spectrum of disease ranges from a self-limiting mild diarrhoea to the advanced and severe illness characteristic of pseudomembranous colitis. The most accurate diagnosis of pseudomembranous colitis is affected by endoscopic detection of colonic pseudomembranes or microabscesses in antibiotic-treated patients who are suffering from diarrhoea, and who have C. difficile and its toxins in their stools. The organism has been associated with outbreaks in hospitals and in extended care facilities for the elderly. It represents an important cause of hospital-acquired infection. C. difficile can be isolated from soil, hospital environments and both human and animal faeces. It is rarely found in the flora of normal adults, but up to 50% of infants may be colonised in the first few months, although disease is rarely present at this age. C. difficile infection is more common in the elderly. The reasons for this are not clear, although there is some evidence to suggest that these patients have a less effective natural barrier to infection. Elderly medical patients, those undergoing general
surgery, oncology patients and those with chronic renal disease are at particular risk of infection by C. difficile.
C diff positive faecal sample
Clostridium difficile ribotyping network (CDRN) service, Department of Microbiology, Leeds General Infirmary, Great George Street, Leeds, LS1 3EX
This test is referred to Leeds General Infirmary by Microbiology at James Cook University Hospital following request from the trust infection prevention and control team.