Corynebacterium ulcerans Infections in Eurasian Beavers (Castor fiber).

The Eurasian beaver (Castor fiber) has been reintroduced successfully in Germany since the 1990s. Since wildlife is an important source of zoonotic infectious diseases, monitoring of invasive and reintroduced species is crucial with respect to the One Health approach. Three Eurasian beavers were found dead in the German federal states of Bavaria, North Rhine-Westphalia and Baden-Wuerttemberg in 2015, 2021 and 2022, respectively. During post-mortem examinations, Corynebacterium (C.) ulcerans could be isolated from the abscesses of two beavers and from the lungs of one of the animals. Identification of the bacterial isolates at the species level was carried out by spectroscopic analysis using MALDI-TOF MS, FT-IR and biochemical profiles and were verified by molecular analysis based on 16-23S internal transcribed spacer (ITS) region sequencing. Molecular characterization of the C. ulcerans isolates using whole-genome sequencing (WGS) revealed a genome size of about 2.5 Mbp and a GC content of 53.4%. Multilocus sequence typing (MLST) analysis classified all three isolates as the sequence type ST-332. A minimum spanning tree (MST) based on cgMLST allelic profiles, including 1211 core genes of the sequenced C. ulcerans isolates, showed that the beaver-derived isolates clearly group on the branch of C. ulcerans with the closest relationship to each other, in close similarity to an isolate from a dog. Antibiotic susceptibility testing revealed resistance to clindamycin and, in one strain, to erythromycin according to EUCAST, while all isolates were susceptible to the other antimicrobials tested.

Corynebacterium pseudotuberculosis Infections in Alpacas (Vicugna pacos).

Alpacas are the major camelid species in Europe held for hobbies, animal-aided therapy, and commercial reasons. As a result, health-related issues associated with alpacas are of growing significance. This especially holds true for one of the most serious infectious diseases, caseous lymphadenitis, which is caused by the bacterial pathogen Corynebacterium (C.) pseudotuberculosis. Our study focuses on post-mortem examinations, the laboratory diagnostic tool ELISA, and the immunoblot technique for the detection of specific antibodies against C. pseudotuberculosis and detection of the causative pathogen in alpaca herds. We examined a total of 232 alpacas living in three herds. Four of these alpacas were submitted for post-mortem examination, revealing abscesses, apostematous and fibrinous inflammation in inner organs, pleura, and peritoneum. Serological investigation using a commercial ELISA based on phospholipase D (PLD) as antigen and an in-lab ELISA based on whole cell antigens (WCA) revealed an overall seroprevalence of 56% and 61.2%, respectively. A total of 247 alpaca sera originating from 232 animals were tested comparatively using the in-lab and the commercial ELISA and showed a substantial degree of agreement, of 89.5% (Cohen's kappa coefficient of 0.784), for both tests. Further comparative serological studies using the two ELISAs and the immunoblot technique were carried out on selected sera originating from 12 breeding stallions and six breeding mares for which epidemiological data and partial C. pseudotuberculosis isolates were available. The results showed the immunoblot to have a sensitivity that was superior to both ELISAs. In this context, it should be emphasized that evaluation of these investigations and the epidemiological data suggest an incubation period of one to two months. Antibiotic susceptibility testing of 13 C. pseudotuberculosis isolates based on the determination of minimal inhibitory concentrations using the broth microdilution method revealed uniform susceptibility to aminopenicillins, cephalosporines, macrolides, enrofloxacin, florfenicol, tetracycline, sulfonamid/trimethoprime, tiamulin, gentamicin, neomycin, spectinomycin, and vancomycin, but resistance to colistin, nitrofurantoin, and oxacillin.

Salmonella infections in reptiles--prevalence, serovar spectrum and impact on animal health.

In a seven year study, 235 lizards, 193 snakes and 111 chelonians were tested for the occurrence of Salmonella enterica. The material for analysis consisted of 251 faecal samples from reptiles suffering from diarrhoea and 288 carcasses of perished or euthanized reptiles. The carcasses were dissected and examined pathohistologically. A total of 35.3% of the lizards, 47.2% of the snakes and 11.7% of the chelonians were found to be Salmonella-positive. Systemic Salmonella infection was detected in 56.1% of the Salmonella-positive lizards and snakes carcasses; 67.4% of these were found to have pathohistological changes of varying severity in the affected organs. The relationship between the systemic Salmonella infection and pathohistological changes was highly significant. Furthermore, systemic Salmonella infections were accompanied by debilitating factors such as parasitic disease, husbandry-associated metabolic or degenerative diseases or viral infection in 63% of the cases. A total of 83 different serovars could be detected, of which 49 occurred in lizards, 36 in snakes and ten in chelonians. Infections with two Salmonella serovars were found in seven cases and in one case with three Salmonella serovars. One infection was associated with a previously undocumented Salmonella serovar in the faecal sample of a water dragon (Subsp. lllb,18:l,v,z13:z).

[Corynebacterium ulcerans infection in roe deer (Capreolus capreolus)]. / Corynebacterium ulcerans-Infektion bei einem Reh (Capreolus capreolus).

This is the first report of a Corynebacterium (C) ulcerans-infection in European roe deer (Capreolus capreolus). The bacterium was isolated from a grapefruit sized abscess of an animal that had been shot. In addition to biochemical tests, the isolate was identified by Fourier transform infrared spectroscopy (FT-IR) and partial sequencing of the rpoB gene. The isolated bacteria showed phospholipase D activity that could be demonstrated by reverse CAMP-test. A tox-gene could be detected by PCR but the Elek-test specific for diphtheria toxin failed.The isolate was compared to two C. ulcerans-strains isolated from wild boar (Sus scrofa) from the state of Baden-Wuerttemberg described recently.

An unusual outbreak of histomonosis in a commercial turkey flock.

In the past histomonosis was very well controlled with Dimetridazole as a treatment and/or Nifursol as feed additive. In the European Union both products were banned in 1995 and 2003, respectively. This was followed by the re-emergence of the disease in the recent years. In the present case a farm with two houses was affected by the disease. In each house 2620 hens and 2620 toms were kept, separated by wire mesh. At the 53rd day of age the toms in house 1 showed general clinical symptoms, accompanied by a slightly raised mortality, which sharply increased in the following days. At necropsy all dead birds showed lesions typical for histomonosis in caeca and liver. Histomonosis was diagnosed by histopathology and PCR. Within five days cumulative mortality was 25.1%.The hens kept at the same house didn't show any symptoms. At day 57 two toms, which were kept in house 2, died and showed similar symptoms and lesions. Within the next three days 48 more birds died. Again the hens in house 2 showed neither clinical signs nor mortality. Treatment trials using herbal products and a change of litter directly after the onset of clinical signs did not reduce the mortality. On day 62 the toms of both houses were euthanized by CO2 in closed containers. The hens were kept until they were slaughtered in week 16 and did not show any evidence of histomonosis.