A COMPARISON OF LISTERIA-MONOCYTOGENES SEROVAR 4B ISOLATES OF CLINICAL AND FOOD ORIGIN IN JAPAN BY PULSED-FIELD GEL-ELECTROPHORESIS

Pulsed-field gel electrophoresis (PFGE) patterns of 102 L. monocytogen es serovar 4b isolates from patients and foods examined in Japan were compared with 16 isolates from foodborne listeriosis episodes which oc curred in North America or Europe. Using a combination of PFGE pattern s with the restriction enzymes SmaI, ApaI, AscI and Sse8387I, 82 clini cal isolates from Japan were categorized into 45 PFGE types: the large st group of 17 isolates (20.7%) were of the same PFGE type as cultures from the large foodborne outbreaks which occurred in California (1985 ) and Switzerland (1983-1987). Twenty cultures from foods on retail sa le in Japan were classified into 12 PFGE types: four isolates were of three PFGE types also recognized among isolates of clinical origin fro m Japan, including the predominant clinical type. (C) 1998 Elsevier Sc ience B.V.