ABSTRACT
This chapter discusses the evidence that establishes the role of antimicrobial resistance as a risk factor for C. difficile infection (CDI). A face was finally put to the disease when in 1978, John Bartlett et al. demonstrated that Clostridium difficile was the causative pathogen associated with antibiotic-associated pseudomembranous colitis. A number of outbreaks associated with severe manifestations of CDI have recently captured the attention of clinicians, epidemiologists, patients, and the media. In brief, the presenting features of CDI typically include watery diarrhea without the presence of visible blood in stool, fever, abdominal pain, cramping, diarrhea, and leukocytosis. Laboratory testing for C. difficile toxins should only be ordered when CDI is suspected, since toxin positivity without clinical symptoms can indicate colonization with a toxigenic strain of C. difficile. In addition to restriction endonuclease analysis, polymerase chain reaction ribotyping, and pulsed field gel electrophoresis, strains can also be distinguished by toxinotyping studies.
