Serotype and phage type distribution of salmonellas from human and non-human sources in Italy in the period 1973-1995.

According to the data collected at the Rome-based National Reference Centre for Enterobacteria, 266,547 Salmonella strains isolated from human sources (226,513) and from non human sources (40,034) were characterised in Italy during the period 1973-1995. The serotype of all isolates, and the antibiotype and phage type of selected isolates were determined. Human-source isolations grew from 4372 in 1973 to 12,310 in 1995: non-human source isolations, from 339 in 1973 to 3459 in 1995. Salm. Typhimurium ranked first in the list of the most common serotypes isolated from both sources in the period 1973-1988 except in the years 1975 and 1976 when it was overtaken by Salm. Wien. Since 1983 Salm. Enteritidis has been among the top ten isolates from animals, and ranked first in the list of isolates from humans in 1988 and from non human sources in 1991. During the last years the number of multidrug-resistant strains, mostly belonging to phage types 104 and 193 of Salm. Typhimurium has been rising. Salmonella strains have also been isolated from numerous extraintestinal infections, almost exclusively caused by Salm. Enteritidis and Typhimurium.