A proposal for source tracking of fecal pollution in recreational waters by pulsed-field gel electrophoresis

This study aimed to identify specific river sources of fecal contamination by applying pulsed-field gel electrophoresis (PFGE) to environmental water samples from a recreational beach in Japan. The genotypes of all Enterococcus faecium and Enterococcus faecalis strains used as indicators of fecal pollution on the recreational beach and rivers were analyzed by PFGE, and the PFGE profiles of the strains were classified at a 0.9 similarity level using dendrogram analysis. PFGE types of E. faecium isolated from Sakai River or urban drainage were classified in the same cluster. Therefore, the probable sources of fecal pollution on the recreational beach were Sakai River and urban drainage. The approaches for microbial source tracking employed in this study used PFGE with Enterococcus species as an indicator can be a potential tool to specify the source(s) of fecal pollution and contribute to improved public health in coastal environments.