BATHER-RELATED MICROBIAL AND YEAST POPULATIONS IN SAND AND SEAWATER

The presence of bacteria and yeasts in water and wet sand was correlat ed with the number of swimmers present on the beach. Water and wet san d samples were collected from two beaches in summer and winter and the number of swimmers present on the beach was counted. Microbiological tests for the counts of coliforms, faecal coliforms, enterococci, S. a ureus, yeasts and moulds were carried out. Water and sand samples were very low in indicator organisms of faecal pollution. Human species of yeasts were are present in water and sand samples of both sites. S. a ureus was isolated From water and sand samples twice in winter. In sum mer, S. aureus was recovered more often from sand than from water samp les in both sites. Water and sand samples in both sites contained sign ificantly more S. aureus in summer than in winter samples. In summer, more yeasts of human origin were present in sand samples while less in water samples. A significant correlation appears between the number o f swimmers present on the beach and S. aureus counts in water samples; the correlation is stronger al the more popular beach. In sand sample s S. aureus counts correlate with the number of swimmers present on th e beach only at the more popular beach. Yeasts of human origin correla te with the number of swimmers on the more popular beach, both in wate r and sand samples. (C) 1997 Elsevier Science Ltd.