Controlli ambientali sulla diffusione di sierotipi di Salmonella spp in acque fluviali

Data on serotypes of Salmonella isolates from rivers are presented.The microrganism was detected in high concentrations in all the sampling sites. These values show its regular occurrence in the examined waters all the time, even if a seasonal trend was observed with higher levels in summer and fall. Salmonella typhimurium and S. infantis were the prevalent serotypes.These serotypes are also among those more prevailing in Italy as it is pointed out by the surveillance network of gastrointestinal infections

Antibiotic Resistance Genes and Salmonella Genomic Island 1 in Salmonella enterica Serovar Typhimurium Isolated in Italy

Fifty-four epidemiologically unrelated multidrug-resistant Salmonella enterica serovar Typhimurium isolates, collected between 1992 and 2000 in Italy, were analyzed for the presence of integrons. Strains were also tested for Salmonella genomic island 1 (SGI1), carrying antibiotic resistance genes in DT104 strains. A complete SGI1 was found in the majority of the DT104 strains. Two DT104 strains, showing resistance to streptomycin-spectinomycin and sulfonamides, carried a partially deleted SGI1 lacking the flo(st), tetR, and tetA genes, conferring chloramphenicol-florfenicol and tetracycline resistance, and the integron harboring the pse-1 gene cassette, conferring ampicillin resistance. The presence of SGI1 was also observed in serovar Typhimurium strains belonging to other phage types, suggesting either the potential mobility of this genomic island or changes in the phage-related phenotype of DT104 strains