Summary

Mice were infected experimentally and subclinically with Corynebacterium kutscheri to recover the organism frommice faeces. The faeces were then cultured using selective furazolidone-nalidixic acid-colimycin agar. The number ofC. kutscheri per gram of fresh faeces varied frommouse tomouse, but once established in the intestine, the organismwas excreted in the faeces for at least five months. Viable bacteria were detected in most of the faecal samples, including those stored in the animal room for five days. The number of organisms in the stored faeces decreased gradually but did not differ significantly from those in the fresh faeces until they had been stored for more than three days. Many infectedmice excreted between 104.77 and 105.37 colony forming units (CFU) of C. kutscheri per day in their faeces, and one mouse even excreted103.74CFUat eightweekspostinfection.Thesevalues showed littledailyvariation.Our present study showed that subclinically infected mice discharged the organism continuously and persistently in their faeces. Therefore, faecal samples would be useful for monitoring infection with C. kutscheri in living mice in a manner that is not stressful for the animals