Article révisé par les pairs
Résumé : In 1997 and 1998 faecal contamination of the Seine river and its estuary was studied for the first time by rapid enzymatic methods, based on the presence of the beta-D-glucuronidase enzyme in E. coli, in parallel with traditional plate counts of faecal coliforms on specific culture medium. Our study focused on a 450 km stretch of the river, including the Parisian area, and presenting highly variable levels of faecal pollution. Both methods showed that wastewater outfalls of the Parisian area and the presence of a maximum turbidity zone (at the mouth of the estuary) had a strong impact on the abundance of faecal coliforms in the river. Downstream from the Parisian outfalls, beta-D-glucuronidase activity measurements decreased 5-6x less rapidly than plate counts suggesting that rapid enzymatic assays could detect enzymatically-active but non-culturable bacteria.