Typing of Clostridium difficile by Western immunoblotting with 10 different

Western blotting (immunoblotting) with antisera against each of 10 reference serogroups was evaluated as a means of typing Clostridium diJfficile. A total of 164 clinical isolates of C. difficik were tested. Variations in band profiles in each serogroup were used to type isolates into subserogroups. This technique was useful for an epidemiological investigation. Outbreaks of Clostridium difficile-associated diarrhea in hospitalized patients are well documented (3, 5, 7, 8, 10). The availability of a simple, rapid, reproducible, and highly discriminatory typing scheme for ' C. difficile would greatly aid studies of both the epidemiology and pathogenicity of C. difficile. Various typing methods have been reported to date (3, 5, 7-10, 13). Of these, Western blotting (immunoblotting) results have been reported to be relatively simple to interpret and the test is sufficiently sensitive for typing of epidemio-logically related C. difficile isolates (9, 10). The studies used Western blotting as the typing method and antiserum pre