ARS | Publication request: A case report describing detection of Rhodoturola minuta fungemia in an ewe lamb

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 25, 2011
Publication Date: December 1, 2011
Citation: Chitko Mckown, C.G., Leymaster, K.A., Heaton, M.P., Griffin, D.D., Veatch, J.K., Jones, S.A., Clawson, M.L. 2011. A case report describing detection of Rhodoturola minuta fungemia in an ewe lamb [Abstract]. Proceeding of the 2011 Conference of Research Workers in Animal Diseases, December 4-6, 2011, Chicago, Illinois. p. 95.

Technical Abstract: An eight-month-old crossbred ewe that was normal upon physical examination was humanely euthanized for tissue collection. Prior to euthanasia, whole blood was collected via jugular venipuncture into 60-ml syringes containing EDTA anticoagulant. After sacrifice, the brain was removed and the choroid plexus harvested. The internal organs appeared normal upon gross examination and one kidney was removed. The choroid plexus and kidney were immediately placed into sterile 50-ml tubes containing ice cold PBS and were transported to the laboratory for cell isolation. Monocytes were purified from whole blood by density gradient centrifugation, and cell suspensions were obtained from the choroid plexus and kidney by mincing the tissue and digestion in 0.25% trypsin. Each tissue-specific cell suspension was placed in a 75-cm**2 tissue culture flask in RPMI culture medium with antibiotic and fungizone, L-glutamine, and 5% FBS, and was cultured at 37 deg C, 5% CO2 in a humidified atmosphere. After several weeks of culture, fungi began budding out of the choroid plexus. Shortly thereafter the budding was observed in the kidney cell cultures--and eventually--in the monocyte cultures as well. Cell monolayers of all lineages appeared healthy and after fungi removal and medium replacement continued to grow. 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. The PCR products were sequenced and BLAST analysis performed. The unknown fungal sequence aligned with 100% identity to Rhodotorula minuta, an emerging opportunistic pathogen. Samples have been 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. USDA is an equal opportunity provider and employer.