Chromobacterium violaceum Infection in a Horse.
Chromobacterium violaceum is an opportunistic pathogen of mammals that produces characteristic violet pigment in bacterial culture. We report pneumonia and septicaemia caused by C. violaceum in a horse. Necropsy examination was performed on a 3-year-old Quarter Horse stallion with a history of recurrent episodes of pneumonia, fever, dyspnoea and sanguineous nasal discharge. The lungs were not collapsed, but they contained dark red foci mixed with white areas, and multiple nodules of firm consistency. Within the liver and kidney there were randomly distributed, multifocal, white pinpoint lesions (0.1-0.5 cm diameter) in the capsule and extending into the parenchyma. The brain and spinal cord contained numerous petechiae. Microscopically, the lung had severe multifocal to coalescing infiltration of degenerate neutrophils within the alveoli and parenchyma associated with extensive areas of necrosis and haemorrhage. Rod-shaped bacteria were often present in the centre of the lesions. There was intense intra-alveolar exudation of fibrin and fibrinoid degeneration of blood vessels associated with thrombosis and ischaemic necrosis adjacent to areas of severe haemorrhage. Similar lesions were present in the liver and kidneys. A pure culture of C. violaceum was obtained from samples of the lung and liver. The identity of the organism was confirmed by amplifying and sequencing the 16S rRNA gene with subsequent analysis of sequence similarity.
Department of Veterinary Pathology, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090 Pr. 42505, Porto Alegre, Brazil. Electronic address: marciahammer@hotmail.com.
Márcia Elisa
ME
Hammerschmitt
Department of Veterinary Pathology, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090 Pr. 42505, Porto Alegre, Brazil.
Veronica Machado
VM
Rolim
Department of Veterinary Pathology, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090 Pr. 42505, Porto Alegre, Brazil.
Gustavo Geraldo Medina
GGM
Snel
Department of Veterinary Pathology, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090 Pr. 42505, Porto Alegre, Brazil.
Franciele Maboni
FM
Siqueira
Department of Veterinary Pathology, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090 Pr. 42505, Porto Alegre, Brazil.
David
D
Driemeier
Department of Veterinary Pathology, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090 Pr. 42505, Porto Alegre, Brazil.
Saulo Petinatti
SP
Pavarini
D000818:Animals; D002861:Chromobacterium; D016905:Gram-Negative Bacterial Infections / Q000662:veterinary*; D006734:Horse Diseases / Q000382:microbiology* / Q000473:pathology*; D006736:Horses; D008297:Male; D018805:Sepsis / Q000662:veterinary
Chromobacterium violaceum; horse; pneumonia; septicaemia