EPIDEMIC DISSEMINATION OF SALMONELLA-ENTERICA SPP ENTERICA SEROVAR BOVISMORBIFICANS IN SOUTHERN ITALY IN THE YEARS 1989-1991

Epidemic strains of Salmonella enterica subsp. enterica serovar Bovism orbificans isolated in southern Italy during the years 1989-1991 were submitted to a molecular epidemiological study in comparison with isol ates identified in the years 1980-1988 in the same geographic area. Ge nomic DNA fragments obtained by digestion with Bg/I or Eco RI hybridiz ed with Escherichia coli rRNA to produce three distinct, but highly re lated patterns. Ribotype 1, which had never been identified before 198 9, was found to characterize most of the strains identified between 19 89 and 1991. Such a finding supports the hypothesis of emergence and s pread of a new bacterial clone associated with the increased number of human infections reported in the same years in southern Italy.