A case of cutaneous toxigenic Corynebacterium ulcerans likely acquired from a domestic dog

Abstract

Introduction Corynebacterium ulcerans can produce diphtheria toxin and although still rare, is now the predominant cause of toxigenic diphtheria infection in the UK, making this organism of great clinical and public health importance. Here we describe a cutaneous case, likely secondary to domestic animal contact. Case presentation A 60-year-old female presented with a slow-healing finger-burn wound. A skin swab cultured Corynebacterium ulcerans, which was confirmed to be toxin producing. She resided with her partner and two dogs, one of which had a chronic skin lesion. Her most recent diphtheria vaccine was in 2009. Four close contacts were identified, two of whom were healthcare professionals, and nose and throat swabs were obtained. The patient was treated with clarithromycin (14 day course), diphtheria vaccine and excluded from work until completion of antibiotics and negative clearance swabs. Contacts were given erythromycin (7 day course), vaccinated and healthcare worker contacts excluded from work until swab negative. A veterinary practitioner swabbed the throats and a skin lesion of their dogs. One contact (partner of patient) and all dog swabs were positive. Partial allelic profiles from MLST supported an epidemiological link. The dogs were treated with antibiotics and antimicrobial skin wash. Repeat swabs for the index case, contact and both dogs were negative following treatment. Conclusion This was a rare case of cutaneous diphtheria secondary to Corynebacterium ulcerans with domestic animals the most likely source, although human-to-human contact could not be excluded, with important human and animal public health implications.

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

“…Concurrent infection with staphylococci has been reported in cases of cutaneous diphtheria in humans (Zakikhany & Efstratiou 2012) and in infection with C. ulcerans in animals (Othieno et al . 2019) As the cats were housed in a multi‐cat “shelter” and Dog A had a history of rehoming from a rescue centre, it is likely that other pathogens such as viruses may have played a role in the aetiology of the clinical signs or may have predisposed to colonisation with C. ulcerans . It is a limitation of this study that investigation for such microorganisms was not carried out.…”

Corynebacterium of thediphtheriaecomplex in companion animals: clinical and microbiological characterization of 64 cases from France

“…Here, we reported 4 cases of toxigenic C. ulcerans in rats or rabbits. Although the cases described in this study are from symptomatic animals, an asymptomatic carrier state of C. ulcerans in dogs, cats, horses, rodents and wild life animals has been described in other studies (Dias et al, 2010;Katsukawa et al, 2016aKatsukawa et al, , 2016bOthieno et al, 2019;Vandentorren et al, 2014). Future studies should investigate the presence of Cdc in healthy animals to better understand and control its transmission to pets.…”

“…ulcerans is now well-established as a zoonotic member of the Cdc. Whereas no human-to-human transmission was reported, human cases have often been associated with animal contacts, and in several cases the genetic fingerprinting of isolates supported an epidemiological link between the animal and human isolates, strongly establishing the zoonotic character of C. ulcerans (Lartigue et al, 2005;Othieno et al, 2019;Vandentorren et al, 2014). The emergence of C. ulcerans has been noted in France, Germany and the UK (Haut Conseil de la santé publique, 2019; Robert Koch-Institut, 2018; Wagner et al, 2010).…”

“…ulcerans is now well-established as a zoonotic member of the Cdc. Whereas no human-to-human transmission was reported, human cases have often been associated with animal contacts, and in several cases the genetic fingerprinting of isolates supported an epidemiological link between the animal and human isolates, strongly establishing the zoonotic character of C. ulcerans (Lartigue et al, 2005;Othieno et al, 2019;Vandentorren et al, 2014) C. ulcerans is widely distributed, having been reported from multiple animal species (Hacker et al, 2016a). Whether pet animals represent a natural reservoir, or (more probably) are themselves contaminated by C. ulcerans from other animal species or sources, is an important question.…”

“…While the transmission of C. diphtheriae is essentially inter-human, C. ulcerans is a zoonotic pathogen (Hacker et al, 2016a; Othieno et al, 2019). No transmission of C. ulcerans among humans was reported since its description in 1995; however, the possiblity of person-to-person transmission cannot be totally excluded (Konrad et al, 2015).…”