Correlation of immunoblot type, enterotoxin production, and cytotoxin production with clinical manifestations of Clostridium difficile infection in a cohort of hospitalized patients.

To determine whether strain-specific differences in immunoblot type, enterotoxin production, or cytotoxin production correlated with clinical presentation of Clostridium difficile infection, we evaluated isolates obtained from 428 prospectively studied hospitalized patients. Of 99 isolates available for immunoblot typing, 61 were recovered from asymptomatic carriers and 38 were from patients with C. difficile-associated diarrhea. Of 17 immunoblot types, the seven types comprising the majority of isolates (82 of 99; 83%) were variably associated with disease. Neither the presence of cytotoxin in the stool nor the production of cytotoxin or enterotoxin by isolates in vitro was significantly different for symptomatic versus asymptomatic patients. Selected host factors were more predictive of symptomatic disease than was the specific infecting C. difficile strain. These results suggest that variations in the clinical severity of C. difficile infection in different patients are not solely strain-specific phenomena related to immunoblot type or to the production of cytotoxin or enterotoxin.