title: Bifidobacterial survival in surface water and implications for microbial source tracking.
abstract: Bifidobacteria are common in the intestines of humans and other animals. Sorbitol-fermenting Bifidobacteria (SFB) are associated with human faecal pollution. The ratio of total Bifidobacteria (TB) to SFB has been proposed to be a means for determining the source (human or animal) of faecal pollution. In this study, SFB were detected in all sewage samples (n = 39) and in 42% of samples of animal origin (n = 24): pig (5/6 positive), poultry (4/8), horse (1/4), and cow (0/6). The TB:SFB ratio was significantly higher in animal samples than in sewage samples (p < 0.01), with the exception of stored poultry manure, which had ratios (1.4-11) similar to the sewage samples (1-17). The lowest ratio in the other animal samples was 40 (pig). The TB:SFB ratio in sewage remained stable over time in surface water, and it may be a useful screening tool to determine the source of faecal pollution in surface water. Bifidobacteria died off in a log linear manner at 4 and 22 degrees C, with rates of disappearance of 0.16 and 0.58 log(days-1), respectively. Faecal coliforms (FC) disappeared more slowly (0.09 and 0.43 log(days-1), respectively). The FC:SFB ratio proved to be an inadequate tool for determining the age of sewage pollution.
authors.affiliation: Swedish University of Agricultural Sciences, Department of Biomedical Sciences and Veterinary Public Health, Uppsala 75007, Sweden. jakob.ottoson@bvf.slu.se
authors.forename: Jakob R
authors.initials: JR
authors.lastname: Ottoson
mesh_terms: D000818:Animals; D001644:Bifidobacterium / Q000302:isolation & purification* / Q000378:metabolism; D005243:Feces / Q000737:chemistry / Q000382:microbiology*; D005285:Fermentation; D006801:Humans; D050296:Microbial Viability; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D013012:Sorbitol / Q000378:metabolism; D014871:Water Microbiology
chemical_list: D012722:Sewage; D013012:Sorbitol