PLASMID DIVERSITY IN SALMONELLA-ENTERITIDIS OF ANIMAL, POULTRY, AND HUMAN-ORIGIN

One hundred thirty-eight isolates of Salmonella enteritidis from human , animal, and avian species were analyzed for the presence of plasmid DNA. Plasmid DNA from S. enteritidis isolates were extracted by a modi fication of a high alkaline extraction procedure. Comparisons were mad e between samples based on the number of plasmids present and their mo lecular weights. There were seven different profiles seen among the 15 human isolates from the Centers for Disease Control. These seven prof iles were recognized with the animal isolates from the National Veteri nary Services Laboratory, the chicken isolates from the northeastern ( NE) region of the United States, and the turkey isolates from Minnesot a (MN). There were no shared profiles between the human isolates and t he chicken isolates from MN. The greatest relationship existed between the human isolates and the chicken isolates from the NE region of the United States, sharing four common profiles. Every Centers for Diseas e Control isolate shared a plasmid profile with chicken isolates from the NE region of the United States. The chicken isolates from MN had n o profiles in common with any isolates from any other groups. The majo rity of animal isolates from National Veterinary Services Laboratory a nd the turkey isolates from MN possessed the virulence-associated 54 k b plasmid alone. This paper describes how plasmid profiles can be used as a tool in epidemiological investigations.