SALMONELLA-ENTERITIDIS IN CANADA

During the last few years the prevalence of Salmonella enteritidis in people in Canada has increased slightly from 9 to 12% of all Salmonella isolates. Nation-wide surveys showed a low prevalence of S. enteritidis in poultry flocks: S. enteritidis was isolated from environmental samples of 2.7% of layer flocks and of 3% of broiler flocks. The overall prevalence of S. enteritidis-contaminated eggs from two flocks with infected hens was less than 0.06%. With the exception of S. enteritidis phage type (PT) 4, which has not been isolated from poultry in Canada, the phage types that occur most commonly in poultry (PT 8, 13 and 13a) are also the most prevalent in people. Phage typing was the most effective method for subdividing S. enteritidis strains. Eighty-three percent of the S. enteritidis isolates from poultry and its environment were sensitive to antimicrobial agents. The reasons why strains of the same phage type differ in virulence need to be elucidated.