APPLICATION OF TYPING BY PULSED-FIELD GEL-ELECTROPHORESIS TO THE STUDY OF CLOSTRIDIUM-DIFFICILE IN A NEONATAL INTENSIVE-CARE UNIT

Pulsed-field gel electrophoresis (PFGE) analysis of restriction patter n polymorphism was applied to type Clostridium difficile isolated from neonates hospitalized in a neonatal intensive care unit, and the resu lts were compared with those of immunoblot analysis. C. difficile was isolated from fecal specimens of 41 (61%) of 67 neonates during a 5-mo nth investigation. All of these neonates were asymptomatic. Fifty-five C. difficile isolates from 32 patients were analyzed by PFGE after di gestion with SmaI and SacII endonucleases and by immunoblotting with 1 0 different antisera. Fifty-three of 55 isolates from 30 patients were identical by PFGE analysis after SmaI and SacII digestion and immunob lot analysis. Two isolates were different from each other and from the epidemic group by both PFGE and immunoblot analysis. All 53 epidemic isolates were nontoxigenic, while the two remaining isolates were toxi genic. These results suggest the nosocomial spread of nontoxigenic C. difficile infection in the neonatal intensive care unit and suggest th at both PFGE and immunoblot are powerful typing tools for the epidemio logical study of C. difficile.