Occurrence of potentially human pathogenic bacteria in the seawater and in the sand of the recreational coastal beach in the southern Baltic Sea

The occurrence and the distribution of potentially human pathogenic bacteria such as Aeromonas, Pseudomonas aeruoginosa, Staphylococcus and Vibrio-like organisms in the sand and the adjacent seawater of the recreational coastal beach were studied. The highest mean number among these four studied groups of bacteria was represented by Aeromonas-like organisms and the lowest one by Staphylococcus-like organisms. Dry sand was inhabited by the highest number of all studied potentially pathogenic bacteria. Within a year, the number of the studied bacteria inhabiting the sand and the seawater showed considerable monthly changes. There were differences in the abundance of potentially pathogenic bacteria between the surface and the subsurface sand layers with a clear decrease in their number toward the deeper layers of the sand.