Isolation of Corynebacterium suis from the prepuce of boars

A survey for prevalence of Corynebacterium suis infection in boars was conducted on a Minnesota farm and at a slaughter plant. Preputial swab specimens were streaked onto Columbia colistin-nalidixic blood agar to which metronidazole (50 mg/L) had been added. Of 97 boars surveyed at a slaughterhouse, 32 (32.9%) were culture-positive, whereas 23 of 38 (60.5%) boars from 1 farm were culture-positive. The lower isolation rate at a slaughterhouse was attributed to the fact that these boars ejaculated before sampling.