Toxigenic Corynebacterium ulcerans isolated from a hunting dog and its diphtheria toxin antibody titer

Abstract

Toxigenic Corynebacterium ulcerans is a zoonotic pathogen that produces diphtheria toxin and causes a diphtheria-like illness in humans. The organism is known to infect and circulate among dogs, which can then transmit it to humans. Furthermore, previous studies have found that C. ulcerans is carried by wild animals, including game animals. In the present study, we tested hunting and companion dogs for the presence of toxigenic C. ulcerans and succeeded in isolating the bacterium from a hunting dog. Moreover, several hunting dogs had serum diphtheria antitoxin titers that were higher than the titers required for protection in humans, suggesting a history of exposure to toxigenic Corynebacterium strains. Notably, ribotyping, pulsed-field gel electrophoresis and tox gene sequencing demonstrated that the isolate from the hunting dog clustered with previously characterized C. ulcerans strains isolated from wild animals, as opposed to groups of isolates from humans and companion dogs. Interestingly, the wild animal cluster also contains an isolate from an outdoor breeding dog, which could have formed a bridge between isolates from wild animals and those from companion dogs. The results presented herein provide insight into the mechanism by which the zoonotic pathogen C. ulcerans circulates among wild animals, hunting and companion dogs, and humans.

Toxigenic Corynebacterium ulcerans associated with upper respiratory infections in cats and dogs

“…2015, Katsukawa et al . 2016). However, acquisition of the tox gene, which is usually encoded on a prophage, may occur readily in C. ulcerans (Meinel et al .…”

“…Isolation of this pathogen in hunting dogs in Japan has led to the suggestion that exposure to wildlife may be an important risk factor for acquisition of C. ulcerans (Katsukawa et al . 2016) and there are a number of reports of C. ulcerans isolation from wild animals (Macgregor et al . 2010, Eisenberg et al .…”

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

“…So far, C. ulcerans isolated in Japan have been categorized into 4 types by ribotyping (Fig. 2 b) [ 24 ]. The owl and shrew-mole isolates showed identical ribotypes (Fig.…”

“…Other ribotypes (R1, R3 and R4) represented human and companion animal isolates. Together with PFGE and toxin gene sequence the isolates have been categorized into three groups [ 24 ]. Owl, shlew-mole, killer whale and outdoor-bred dog were categorized together in one group (Group II) that did not contain human isloates.…”

Mutation and Diversity of Diphtheria Toxin inCorynebacterium ulcerans

“…Reports of human infections with C. ulcerans have increased during the past 20 years, and C. ulcerans is a recognized emerging human pathogen ( 1 ). Humans can contract toxin-producing C. ulcerans from companion animals ( 2 , 3 ). Human death can occur if appropriate treatment is delayed ( 4 ).…”