Abstract
AbstractObjectivesCorynebacteria of thediphtheriaecomplex (Cdc) can cause diphtheria in humans and have been reported from companion animals. We aimed to describe animal infection cases caused byCdcisolates.Methods18 308 animals (dogs, cats, horses and small mammals) with rhinitis, dermatitis, non-healing wounds and otitis were sampled in metropolitan France (August 2019 to August 2021). Data on symptoms, age, breed, and the administrative region of origin were collected. Cultured bacteria were analyzed fortoxgene presence, for production of the diphtheria toxin, for antimicrobial susceptibility, and genotyped by multilocus sequence typing.ResultsC. ulceranswas identified in 51 cases, 24 of which were toxigenic. Rhinitis was the most frequent presentation (18/51). Eleven cases (6 cats, 4 dogs, 1 rat) were mono-infections. Large breed dogs, especially German Shepherds (9 of 28 dogs; p < 0.00001) were overrepresented.C. ulceransisolates were susceptible to all tested antibiotics.tox-positiveC. diphtheriaewas identified in 2 horses. Last, 11 infections cases (9 dogs, 2 cats; mostly chronic otitis, and 2 sores) hadtox-negativeC. rouxii, a recently defined species.C. rouxiiandC. diphtheriaeisolates were susceptible to most antibiotics tested, and almost all of these infections were polymicrobial.ConclusionsMonoinfections withC. ulceranspoint towards a primary pathogenic potential to animals.C. ulceransrepresents an important zoonotic risk, andC. rouxiimay represent a novel zoonotic agent. This case series provides novel clinical and microbiological data onCdcinfections, and underlines the need for management of animals and their human contacts.ImportanceWe report on the occurrence, clinical and microbiological characteristics of infections caused by members of the Corynebacteria of thediphtheriaecomplex (Cdc) in companion animals. This is the first study based on the systematic analysis of a very large animal cohort (18 308 samples), which provides data on the frequency of Cdc isolates in various types of clinical samples from animals. Awareness of this zoonotic bacterial group remains low among veterinarians and veterinary laboratories, among which it is often considered a commensal bacteria of animals. We suggest that in case of Cdc detection in animals, the veterinary laboratories should be encouraged to send the samples to a reference laboratory for analysis of the presence of thetoxgene. This work is relevant to the development of guidelines in case of Cdc infections in animals, and underlines their public health relevance given the zoonotic transmission risk.
Publisher
Cold Spring Harbor Laboratory