The characterization of Danish isolates of Salmonella enterica serovar Enteritidis by phage typing and plasmid profiling: 1980-1990.

Plasmid profiling, phage typing and antimicrobial resistance typing have been carried out on 736 isolates of Salmonella enterica serovar Enteritidis collected in Denmark during the period 1980 to 1990. Strains originated from cases of human salmonellosis, broiler poultry flocks, layer poultry flocks, quarantined imported poultry, environmental samples from hatchery units, and from bovines. Phage type (PT) 1 was found to be the most common type among isolates of poultry origin (57.6%) followed by PT4 (28.8%). Isolates belonging to PT8 were found exclusively in imported birds. Phage typing of a representative sample of human isolates revealed the predominance, as in most other Western European countries, of PT4 (61.8%). PT1, however, was found in 17.0% of human strains, a much higher incidence than expected. Antibiotic resistance was observed in 4 out of 107 human isolates (3.7%) and 2 out of 205 non-human isolates (1%) tested.