Clostridium difficileBug of the Month

June 2011

The Bug

• Anaerobic spore forming motile gram-positive rod

• Irregular white colonies on blood agar

• Three exotoxins

• Toxin A

• Toxin B

• Binary toxin

Toxins

• Toxins A and B are produced maximally in stationary phase during nutrient limitation

• Toxins A and B are translocated across host membranes where they inhibit Rho GTPases by glucosylation

• This results in loss tight junctions, cell rounding and cell death

• Binary toxin has ADP-ribosylating activity

Epidemiology

0

15000

30000

45000

60000

20032004

2007C

ases

• Hospital superbug!

• Present in intestine of 2-3% of asymptomatic adults

• may increase to 30% in hospital

• 60-70% in neonates

Clinical presentation

• C. diffficile antibiotic associated diarrhoea (CDAD)

• Pseudomembranous colitis (PMC) results in significant mortality

• Infection is usually in >65 years and associated with antibiotics, bowel surgery or chemotherapy

• Symptoms include colicky abdominal pain, bloating and watery diarrhoea. It has a characteristic smell!

• Extra-intestinal disease is rare

Management

• Infection control/barrier nursing

• Stop current antibiotics if at all possible

• CDAD is metronidazole or vancomycin for 14d

• Fecal transfer