Rapid detection of human fecal contamination in estuarine environments by PCR targeting of Bifidobacterium adolescentis.

Detection of Bifidobacterium adolescentis was used as an effective genetic marker of human fecal contamination in Georgia estuaries. Enterococci enumerations on mEI media indicated that a tributary to the Little Satilla River with 516 CFU/100 ml was the most polluted of all the rivers tested. Extracted DNA from eight river water samples was subjected to a two-step nested PCR protocol using genus and species specific primers for Bifidobacterium spp. and B. adolescentis. B. adolescentis was detected from extracted DNA in Dunbar River, Black Bank Creek, and in a Little Satilla River tributary which demonstrates the presence of human fecal contamination in these three rivers. In the five other estuaries tested including West Point-Federica River and the Altamaha River, which both had less than 16 CFU/100 ml of enterococci, B. adolescentis was not detected.