Relationship between presence of Salmonella and indicators of faecal pollution in aquatic habitats.

The presence of Salmonella and its relationship with indicators of faecal pollution was investigated in aquatic habitats. The highest frequency was obtained in rivers (58.7% of samples) followed by freshwater reservoirs (14.8%) and sea water (5.9%). The sporadic presence of Salmonella (< 30%) on beaches with low concentrations of faecal streptococci (mean 25 CFU (100 ml)-1) may represent a potential risk for bathers in agreement with data found in previous epidemiological studies. Absence of Salmonella was observed only on beaches with very low densities (CFU (100 ml)-1) of indicator organisms (25 total coliforms, 13 faecal coliforms and 17 faecal streptococci).