Acute death of kangaroos in a zoo due to highly pathogenic Corynebacterium pseudotuberculosis and Yersinia pseudotuberculosis

ABSTRACT

Background: “Lumpy jaw” is disease effecting wallabies and kangaroos, particularly in Macropus rufus and Macropusgiganteus. In the most serious situations, additional tooth loss and fistulas follow, accompanied by a stench, weight loss,and eventually death due to sepsis or blood poisoning. “Lumpy jaw” disease has seriously affected the normal display andhealth of kangaroos, and cause a huge economic loss. There was an outbreak of jaw infection in kangaroos at the HongshanForest Zoo. Two Macropus giganteus and two Macropus rufus died of “lumpy jaw”. The main objective of the describingcase was to isolate pathogens, provide a basis for follow-up treatment, and serve to establish a disease prevention protocol.Case Four grown-up kangaroos (two Macropus giganteus and two Macropus rufus) were raised in Hongshan Forest Zoo,which had obviously clinical symptoms, such as oral lesions of pus, necrotic tissue, rotting teeth, then died of “lumpyjaw”. Oral swab samples were collected from the lesion sites of the dying kangaroos. Mice experiments were conducted toexamine the pathogenicity of the strains. Tests of antimicrobial susceptibity were performed to prescribe with better drugtreatments for kangaroos. Corynebacterium pseudotuberculosis and Yersinia pseudotuberculosis were identified based onmorphology, culture characteristics and biochemical tests. Corynebacterium pseudotuberculosis (G+) in Sucrose, Mannitol,Lactose, Maltose, Glucose tubes were positive, that acids and gases both production, in Gelatin liquefaction, Indol test,MR were positive, that only acids production, others were negative; Yersinia pseudotuberculosis (G-) in Urea, MR werepositive, that only acids production, others were negative.The infected mice presented with gum erosion or ulcers whenthe two pathogens were injected subcutaneous at the oral regional by 2-3 point at 0.2 mL of individual strains 1.0×109CFU/mouse...