Duration of viability and the growth and expiration rates of group E streptococci in soil.

In irradiated and nonirradiated feedlot and pasture soils inoculated with group E streptococci, the organism was not recovered 17 days postinoculation from either the irradiated or nonirradiated feedlot soils incubated at 37 C, but survived in the irradiated pasture soils for 24 and 31 days postinoculation. The streptococci survived in irradiated and nonirradiated soils incubated at 4 C for 116 days and in one irradiated feedlot soil for 165 days. The population of streptococci did not increase in either irradiated or nonirradiated soil, and the expiration rate was greater in the soils incubated at 37 and 25 C than at 4 C. With the relatively prolonged duration of viability of group E streptococci in soil at 4 C, it is suggested that soil contaminated with exudate from draining abscesses of infected swine could act as a source of infection during the colder season.