Gamma radiation inactivation of enterococci.

Radiation survival curves were determined for 7 strains of Enterococcus faecium, 10 strains of E. faecalis, and 8 strains of the proteolytic variety of E. faecalis. The D values (i.e. the doses giving 90% reduction of viable counts) ranged from 5.0–47 kGy for the E. faecium strains, 3.5–21 kGy for the E. faecalis strains, and 3.0–4.5 kGy for the proteolytic variants of E. faecalis. The survival curves were linear for most strains but some exhibited significant non-linear trends.