USEFULNESS OF MOLECULAR-GENETIC MARKERS IN THE TYPING OF SALMONELLA-ENTERICA SEROVAR ENTERITIDIS CAUSING A FOOD-BORNE OUTBREAK

A combination of serotyping-phagetyping and three molecular genetic ma rkers (plasmid analysis, chromosomic DNA restriction pattern and ribos omal RNA gene restriction pattern or ribotyping) was used in the typin g of Salmonella enterica causing a food-borne outbreak. The isolates a nalysed, 29 from stools and eight from foods, belonging to serovar Ent eritidis-phagetype A, carried a 36-MDa plasmid, showed a similar DNA r estiction pattern and the same ribopattern. These data indicate that o nly one strain was involved. The DNA pattern and ribopattern of this s train were indistinguishable from the patterns of a serovar Enteritidi s-phagetype A strain which has caused salmonellosis in Asturias, Spain , since, at least, 1984.