Isolation of Erysipelothrix rhusiopathiae from tonsils of apparently normal swine by two methods

Erysipelothrix rhusiopathiae was isolated from the tonsils of 62 of 63 (98%) apparently normal pigs, using 2 procedures: (1) enrichment culture at 5 C followed by mouse inoculation, and (2) Wood's technique. There was no significant difference (P less than or equal to 0.01) in the sensitivity of erysipelothrix detection between the 2 procedures. Each of the isolates selected for identification had morphologic and tinctorial properties consistent with E rhusiopathiae and was identified by direct immunofluorescence.