Purulent pericarditis due to Klebsiella oxytoca in two lions: clinicopathological and microbiological findings

Abstract

Pericarditis caused by gram-negative bacteria is uncommon in human and animals. Two about 2-month-old male African lions were referred with a history of lethargy, anorexia, and progressive weight loss. The complete blood cell count and analysis revealed severe neutrophilic leukocytosis with left shift, and also an increase in band neutrophils. Despite intensive antibiotic and supportive therapies, the lions died. Postmortem examinations showed hydropericardium with more than 20 ml malodorous milky dark purulent exudates. Bacteriologic examination of the pericardial exudates showed round-shaped colonies containing rod-shaped gram-negative bacteria. Klebsiella oxytoca was identified on the basis of colony morphology, microscopic Gram stain, and biochemical tests characteristics. Histopathologic examination revealed the severe necrosis and inflammation associated with the thickening of pericardium due to the infiltration of neutrophils as purulent epicarditis and pericarditis. Based on the bacteriological and histopathological findings, purulent pericarditis due to K. oxytoca was diagnosed. To the best of our knowledge, up to now, K. oxytoca pericarditis has not been reported in animals, including lions.