Corynebacterium ulcerans from diseased wild boars

Area of Science:

• Veterinary Microbiology
• Zoonotic Diseases
• Bacterial Pathogenesis

Background:

• Caseous lymphadenitis is a significant disease in wild boar populations.
• Identifying the causative agents of bacterial infections in wildlife is crucial for public health.
• Distinguishing between closely related bacterial species like Corynebacterium ulcerans and Corynebacterium pseudotuberculosis can be challenging.

Purpose of the Study:

• To identify and characterize Corynebacterium strains isolated from diseased wild boars.
• To investigate the presence of the diphtheria toxin gene in these isolates.
• To assess the potential of wild game as a reservoir for zoonotic Corynebacterium ulcerans.

Main Methods:

• Bacterial isolation and culture from wild boar lymph nodes.
• Biochemical profiling and phospholipase D activity testing.
• Molecular identification using Fourier-transformed infrared spectroscopy (FTIR) and gene sequencing (16S rRNA, rpoB).
• Detection and sequencing of the diphtheria toxin (tox) gene via PCR.

Main Results:

• Two Corynebacterium strains were isolated from wild boars with caseous lymphadenitis.
• Both strains tested positive for phospholipase D.
• Molecular methods confirmed both isolates as Corynebacterium ulcerans.
• The diphtheria toxin (tox) gene was detected in both strains, with unique sequence variations.
• Diphtheria toxin production was not detected in vitro.

Conclusions:

• Wild boars can harbor Corynebacterium ulcerans strains possessing the diphtheria toxin gene.
• The identified strains exhibit distinct genetic features compared to other known Corynebacterium ulcerans.
• Wild game populations may represent a potential reservoir for zoonotic Corynebacterium ulcerans, posing a public health concern.