Italian experience in Salmonella enteritidis 1978-1988: characterization of isolates from food and man.

Salmonella enteritidis accounted for 5.45% of the 118.685 Salmonella isolates from man and for 2.65% of the 3.315 Salmonella isolates from food in Italy in the eleven year period 1978 to 1988. In the years 1978-1982 no S. enteritidis strain was isolated from eggs and poultry; in the years 1983-1988 the 53% of S. enteritidis isolates from food were from eggs and poultry. In 1989 S. enteritidis accounted for 744 isolates from man and 22 from food of which 80% were from eggs and poultry (partial data). In that year 18 outbreaks caused by S. enteritidis were reported to the National Centre of Enteric Pathogens in Rome. Characteristics of 81 S. enteritidis isolates were examined of which 27 were from sporadic cases involving humans and 40 from outbreaks in humans; 14 isolates were from food, all but one connected with the outbreaks. All the isolates studied were sensitive to the antibiotics tested; plasmid profile analysis showed a predominant profile pattern in both epidemic and non-epidemic strains; lysine decarboxylase was present in all the strains tested. Although in at least three epidemics a common supplier of eggs was proved, the source was not identified. Unfortunately it was not possible to determine the phage type of isolates because of the unavailability of specific phages.