Toxigenic Corynebacterium ulcerans isolated from a wild bird (ural owl) and its feed (shrew-moles): comparison of molecular types with human isolates.

Background: Corynebacterium ulcerans is a pathogen causing diphtheria-like illness to humans. In contrast to diphtheria by Corynebacterium diphtheriae circulating mostly among humans, C. ulcerans infection is zoonotic. The present study aimed to clarify how a zoonotic pathogen C. ulcerans circulates among wild birds and animals.

Results: By screening 380 birds, a single strain of toxigenic C. ulcerans was isolated from a carnivorous bird, ural owl (Strix uralensis). The bacterium was also isolated from two individuals of Japanese shrew-mole (Urotrichus talpoides), a food preference of the owl. Analysis by ribotyping showed that the owl and mole isolates were classified in a group, suggesting that C. ulcerans can be transmissible among wild birds and their prey animals. Moreover, our isolates were found to belong to a group of previously reported C. ulcerans isolates from dogs and a cat, which are known to serve as sources for human infection.

Conclusion: The findings suggest that the shrew-mole may be a potential reservoir of a zoonotic pathogen C. ulcerans.