艱難梭狀桿菌(Clostridium difficile)為厭氧革蘭陽性產孢桿菌，主要是造成使用抗生素後引起下痢之重要致病菌，近年來發現此菌在社區感染有增加的趨勢。疾病症狀可從輕微的下痢，至嚴重且致命的偽膜性腸炎，更嚴重可能導致死亡。近十年來，C. difficile 造成的疾病在許多地區有明顯增加的趨勢，原因之一為出現具有高毒素的菌株，PCR ribotype 027 基因型。因此，有越來越多對於C. difficile 毒力因子、治療與預防的相關研究。本文主要概述C. difficile 相關疾病的致病機制、流行病學、臨床表徵、診斷方法、以及治療策略和感染管控。

Clostridium difficile, an anaerobic gram-positive spore-forming bacillus, is one of the most important causes of healthcare associated diarrhea and is increasingly important as a community pathogen. C. difficile
infection ranges from mild diarrhea to a severe, life-threatening pseudomembranous colitis (PMC) and can result in death. The incidence of C. difficile-associated disease has raised dramatically over the last decade, partly due to the emergence of a highly virulent strain, C. difficile PCR ribotype 027. These findings lead to increased research interest aiming at the discovery of new virulence factors and
the development of new treatment and prevention regimens. This article summarizes the pathogenesis and epidemiology of C. difficile-associated
diseases, the clinical spectrum and laboratory methods to diagnose C. difficile infection, and current strategies of treatment and infection control.