Immune responses to Clostridium difficile infection

Abstract

Clostridium difficile is the causal agent of antibiotic-associated diarrhea and is a leading cause of hospital-acquired infections in the US. C. difficile has been known to cause severe diarrhea and colitis for more than 30 years, but the emergence of a newer, hypervirulent strain of C. difficile (BI/NAP1) has further compounded the problem, and recently both the number of cases and mortality associated with C. difficile-associated diarrhea have been increasing. One of the major drivers of disease pathogenesis is believed to be an excessive host inflammatory response. A better understanding of the host inflammation and immune mechanisms that modulate the course of disease and control host susceptibility to C. difficile could lead to novel (host-targeted) strategies for combating the challenges posed by this deadly infection. This review summarizes our current knowledge of the host inflammatory response during C. difficile infection.

Figure 1. Compound tomography (CT) scan of patient with C. difficile colitis showing diffuse thickening along the entire colon

CT findings in patients with C. difficile colitis include colonic thickening, peri-colonic stranding edema, and ‘accordion sign’ (oral contrast material trapped between edematous haustral folds).

Figure 2

Pathogenesis of C. difficile-associated disease.