Corynebacterium oculi-related bacterium may act as a pathogen and carrier of antimicrobial resistance genes in dogs: a case report.

BACKGROUND: The genus Corynebacterium comprises well-known animal and human pathogens as well as commensals of skin and mucous membranes. Species formerly regarded as contaminants are increasingly being recognized as opportunistic pathogens. Corynebacterium oculi has recently been described as a human ocular pathogen but has so far not been reported in dogs. CASE PRESENTATION: Here we present two cases of infection with a novel Corynebacterium sp., a corneal ulcer and a case of bacteriuria. The two bacterial isolates could not be identified by MALDI-TOF MS. While 16 S rRNA gene (99.3% similarity) and rpoB (96.6% identity) sequencing led to the preliminary identification of the isolates as Corynebacterium (C.) oculi, whole genome sequencing revealed the strains to be closely related to, but in a separate cluster from C. oculi. Antimicrobial susceptibility testing showed high minimal inhibitory concentrations of lincosamides, macrolides, tetracycline, and fluoroquinolones for one of the isolates, which also contained an erm(X) and tet-carrying plasmid as well as a nonsynonymous mutation leading to an S84I substitution in the quinolone resistance determining region of GyrA. CONCLUSIONS: While the clinical signs of both dogs were alleviated by antimicrobial treatment, the clinical significance of these isolates remains to be proven. However, considering its close relation with C. oculi, a known pathogen in humans, pathogenic potential of this species is not unlikely. Furthermore, these bacteria may act as reservoir for antimicrobial resistance genes also in a One Health context since one strain carried a multidrug resistance plasmid related to pNG3 of C. diphtheriae.

Actinomycosis in a gray four-eyed opossum (Philander opossum) caused by a novel species of Schaalia.

BACKGROUND: Infective lesions of the jaws and adjacent tissues (lumpy jaw disease, LJD) have been recognized as one major cause of death of captive macropods. Fusobacterium necrophorum and Actinomyces species serve as the main source of LJD in kangaroos and wallabies. Currently, little is reported about LJD or similar diseases in opossums. CASE PRESENTATION: Here we report a case of actinomycosis resembling the entity lumpy jaw disease in a gray four-eyed opossum, caused by a novel species of Schaalia. A 2.8 year old male Philander opossum was presented with unilateral swelling of the right mandible. After an initial treatment with marbofloxacin, the opossum was found dead the following day and the carcass was submitted for necropsy. Postmortem examination revealed severe mandibular skin and underlying soft tissue infection with subsequent septicemia as the cause of death. Histological examination demonstrated Splendore-Hoeppli phenomenon, typically seen in classical cases of actinomycosis. Bacteriology of liver and mandibular mass yielded a previously undescribed species of Schaalia, whose 16 S rRNA gene sequence was 97.0 % identical to Schaalia canis. Whole genome sequencing of the opossum isolate and calculation of average nucleotide identity confirmed a novel species of Schaalia, for which no whole genome sequence is yet available. CONCLUSIONS: The herewith reported Schaalia infection in the gray four-eyed opossum resembling classical actinomycosis gives a novel insight into new exotic animal bacterial diseases. Schaalia species may belong to the normal oral microbiome, as in macropods, and may serve as a contributor to opportunistic infections. Due to the lack of current literature, more insights and improved knowledge about Schaalia spp. and their pathogenicity will be useful to choose appropriate therapy regimens and improve the treatment success rate and outcome in exotic and endangered species.

An unusual case of bovine anthrax in the canton of Jura, Switzerland in 2017.

BACKGROUND: Anthrax caused by Bacillus anthracis is a zoonotic disease mainly affecting herbivores. The last Swiss outbreak was over 20 years ago. We describe a recent anthrax outbreak involving two cows from the same herd. One cow was designated as a peracute clinical case with sudden death and typical lung lesions, while the other cow presented with protracted fever and abortion. CASE PRESENTATION: On April 29th 2017, a 3.5-year-old Montbéliard dairy cow was found dead while out at pasture with haemorrhage from the nose. The veterinarian suspected pneumonia and performed a necropsy on site. Subsequently, a lung and liver sample were sent to the laboratory. Unexpectedly, Bacillus anthracis was isolated, a pathogen not found in Switzerland for decades. Several days later, a second cow from the same farm showed signs of abortion after protracted fever. Since these symptoms are not typical for anthrax, and the bacteria could not be demonstrated in blood samples from this animal, a necropsy was performed under appropriate biosafety measures. Subsequently, Bacillus anthracis could be isolated from the placenta and the sublumbal lymph nodes but not from the blood, liver, spleen and kidney. The outbreak strain (17OD930) was shown to belong to the lineage B.Br.CNEVA, the same as Swiss strains from previous outbreaks in the region. We speculate that the disease came from a temporarily opened cave system that is connected to an old carcass burial site and was flushed by heavy rainfall preceding the outbreak. CONCLUSION: Even in countries like Switzerland, where anthrax is very rare, new cases can occur after unusual weather conditions or ground disturbance. It is important for public officials to be aware of this risk to avoid possible spread.