The hamster model of intraperitoneal Burkholderia mallei (glanders)

Thirty-one female Syrian hamsters (Mesocricetus auratus) were inoculated intraperitoneally with a lethal dose of Burkholderia mallei (Budapest strain). Hamsters were killed postinoculation on days 0 through 6. Lesions were first noted in the spleens on postinoculation day 1, and in mediastinal and mesenteric lymph nodes, mediastinum, liver, and bone marrow on day 2. Lesions were present in the lung and submandibular lymph nodes on day 3, and in the brain on day 5. The characteristic histopathologic change was necrotizing pyogranulomatous inflammation, often with hemorrhage. Lesions indicative of impaired vascular perfusion, such as ischemia and infarction, were evident at the later time points. Pathologic changes generally increased in severity and distribution with time, and almost all tissues were ultimately affected. Our findings suggest that intraperitoneal bacteria were rapidly transported to mediastinal lymph nodes by transdiaphragmatic lymphatics and ultimately seeded other tissues hematogenously. The results of the study indicate that the Syrian hamster is a useful small animal model for glanders.