ARS | Publication request: Rhodotorula minuta fungemia in a ewe lamb

Submitted to: Transboundary and Emerging Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 2013
Publication Date: N/A

Interpretive Summary: An 8-month-old crossbred female sheep was humanely euthanized in order to collect tissues for cell line development. The sheep was normal upon physical examination. Tissues collected included the choroid plexus from the brain, kidney, and blood. About three weeks after cell cultures were started, fungi began budding out of the brain cells. After an additional three weeks, budding fungus was observed in the kidney cells and eventually in the blood cells as well. Serum from the sheep was submitted to the Veterinary Diagnostic Laboratory at Colorado State University for fungal diagnosis and was found negative for the fungal diseases Aspergillosis, Blastomycosis, Coccidiomycosis, and Histoplasmosis. DNA was isolated from the fungi collected from the cell culture supernatants and was used to determine the identity using molecular diagnostic techniques. Fungal samples were simultaneously submitted to The Fungal Testing Laboratory at The University of Texas Health Science Center at San Antonio. The fungal DNA profile matched with 100% identity to Rhodotorula minuta in agreement with results from The Fungal Testing Laboratory identification. Rhodotorula minuta is an emerging opportunistic pathogen, and should be considered as a causative agent in cases of fungal infections in sheep. We believe this to be the first report of Rhodotorula minuta infection in a sheep in the United States.

Technical Abstract: An 8-mo-old crossbred ewe, normal upon physical examination, was humanely euthanized for tissue collection. After approximately three weeks in tissue culture, fungi began budding out of cells obtained from the choroid plexus. After an additional three weeks, budding was observed in kidney cell cultures, and eventually in monocyte cultures as well. Serum from the lamb was submitted to the Veterinary Diagnostic Laboratory at Colorado State University for fungal diagnosis and was found negative for Aspergillus, Blastomyces, Coccidiodomycosis, and Histoplasmosis. DNA was isolated from fungi collected from tissue culture supernatants, and used in a set of pan-fungal PCR assays with DNA from Candida acting as a positive control. PCR products were sequenced and BLAST analysis performed. The unknown fungal sequence aligned with 100% identity to Rhodotorula minuta an emerging opportunistic pathogen. Samples were submitted to The Fungal Testing Laboratory at The University of Texas Health Science Center at San Antonio for additional validation. We believe this to be the first report of Rhodoturola fungemia in a sheep in the United States.