The enterococcal surface protein, Esp, originally found in Enterococcus faecalis, has been associated with increased virulence, colonization, and biofilm formation (2, 3, 5, 6). Recently, a variant esp gene was found in Enterococcus faecium isolates from humans (L. Baldassarri, L. Burtuccini, M. G. Ammendolia, G. Gherardi, and R. Creti, Letter, Lancet 357:1802, 2001; R. J. Willems, W. Homan, J....
