title: Incidence of the enterococcal surface protein (esp) gene in human and animal fecal sources.
abstract: The occurrence of the enterococcal surface protein (esp) gene in the opportunistic pathogens Enterococcus faecalis and E. faecium is well-documented in clinical research. Recently, the esp gene has been proposed as a marker of human pollution in environmental waters; however, information on its relative incidence in various human and animal fecal sources is limited. We have determined the occurrence of the esp gene in enterococci from human (n=64) and animal (n=233) fecal samples by polymerase chain reaction using two primer sets: one presumably specific for E. faecium (esp(fm)) and the other for both E. faecalis and E. faecium (esp(fs/fm)). We believe that this research is the first to explore the use of esp(fs/fm) for the detection of human waste in natural environmental settings. The incidence in human sources was 93.1% esp(fm) and 100% esp(fs/fm) in raw sewage influent; 30% for both esp(fm) and esp(fs/fm) in septic waste; and 0% esp(fm) and 80% esp(fs/fm) in active pit toilets. The overall occurrence of the gene in animal feces was 7.7% (esp(fs/fm)) and 4.7% (esp(fm)); animal types with positive results included dogs (9/43, all esp(fm)), gulls (10/34, esp(fs/fm); 2/34, esp(fm)), mice (3/22, all esp(fs/fm)), and songbirds (5/55, all esp(fs/fm)). The esp gene was not detected in cat (0/34), deer (0/4), goose (0/18), or raccoon (0/23) feces. The inconsistent occurrence, especially in septic and pit toilet sewage, suggests a low statistical power of discrimination between animal and human sources, which means a large number of replicates should be collected. Both esp(fm) and esp(fs/fm) were common in raw sewage, but neither one efficiently differentiated between animal and other human sources.
authors.affiliation: U.S. Geological Survey, Great Lakes Science Center, Lake Michigan Ecological Research Station, 1100 Mineral Springs Road, Porter, Indiana 46304, USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Whitman
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Przybyla-Kelly
authors.forename: Dawn A
authors.initials: DA
authors.lastname: Shively
authors.forename: Muruleedhara N
authors.initials: MN
authors.lastname: Byappanahalli
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D013293:Enterococcus faecalis / Q000235:genetics* / Q000472:pathogenicity; D004784:Environmental Monitoring; D005243:Feces / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial; D014644:Genetic Variation; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D018570:Risk Assessment; D012722:Sewage / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D012722:Sewage; C116707:enterococcal surface protein, esp