K. Przybyla-Kelly D.A. Shively M.N. Byappanahalli R.L. Whitman 2007 The occurrence of the enterococcal surface protein (<i>esp</i>) gene in the opportunistic pathogens <i>Enterococcus faecalis</i> and <i>E. faecium</i> is well-documented in clinical research. Recently, the <i>esp</i> 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 <i>esp</i> gene in enterococci from human (<i>n</i> = 64) and animal (<i>n</i> = 233) fecal samples by polymerase chain reaction using two primer sets: one presumably specific for <i>E. faecium</i> (<i>esp</i>_fm) and the other for both <i>E. faecalis</i> and <i>E. faecium</i> (<i>esp</i>_fs/fm). We believe that this research is the first to explore the use of <i>esp</i>_fs/fm for the detection of human waste in natural environmental settings. The incidence in human sources was 93.1% <i>esp</i>_fm and 100% <i>esp</i>_fs/fm in raw sewage influent; 30% for both <i>esp</i>_fm and <i>esp</i>_fs/fm in septic waste; and 0% <i>esp</i>_fm and 80% <i>esp</i>_fs/fm in active pit toilets. The overall occurrence of the gene in animal feces was 7.7% (<i>esp</i>_fs/fm) and 4.7% (<i>esp</i>_fm); animal types with positive results included dogs (9/43, all <i>esp</i>_fm), gulls (10/34, <i>esp</i>_fs/fm; 2/34, <i>esp</i>_fm), mice (3/22, all <i>esp</i>_fs/fm), and songbirds (5/55, all <i>esp</i>_fs/fm). The <i>esp</i> 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 <i>esp</i>_fm and <i>esp</i>_fs/fm were common in raw sewage, but neither one efficiently differentiated between animal and other human sources. application/pdf 10.1021/es070817t en Incidence of the enterococcal surface protein (<i>esp</i>) gene in human and animal fecal sources article