Sporobolomyces spp

From Dog
A dog which died from Sporobolomyces roseus, showing irregularly branching septate hyphae in the midst of a granulomatous meningencephalomyelitis[1]

Sporobolomyces are a common phylloplane ballistoconidium–forming microbotryomycetan yeast commonly isolated worldwide from air, tree leaves and rotting fruit and vegetables[2][3].

They cause disease primarily in immunocompromised dogs.

Species which are pathogenic to dogs include:

  • Sporobolomyces roseus
  • Sporobolomyces salmonicolor (mainly humans)[4]
  • Sporobolomyces koalae (mainly koalas)

Few reports of systemic mycosis have been reported, but a disseminated mycosis with granulomatous meningoencephalomyelitis has been noted in a German Shepherd dog[1].

The affected patient, which rapidly succumbed to systemic sporobolomycetosis, presented with neurological disease characterized by ataxia, circling, fever, depression and blindness.

MRI imaging revealed poorly defined foci of contrast enhancement were seen in the right frontal lobe and both parietal lobes of the cerebrum and in the left cerebellum.

A definitive diagnosis required histological examination of brain samples since blood tests, imaging and CSF analysis were unrewarding.

Histologically, this yeast produced intracerebral granulomas of epithelioid macrophages and multinucleated giant cells arranged around eosinophilic granular material, containing fibrin and cellular debris.

Human infections show similar signs with meningitis and endophthalmitis predominating[5], and diagnosis is usually achieved with CSF analysis using PCR assays[6].

A differential diagnosis would include other meningoencephalitis-causing fungi such as Cryptococcus spp, Blastomyces dermatitidis, Histoplasma capsulatum, Coccidioides immitis, Cladophialophora bantiana, Aspergillus spp and Fusarium spp.

With sublethal cases, empirical treatment would require use of amphotericin B and/or itraconazole for 4 - 6 months[7].


References

  1. 1.0 1.1 Saey V et al (2011) Granulomatous meningoencephalitis associated with Sporobolomyces roseus in a dog. Vet Pathol 48(6):1158-1160
  2. Janisiewicz WJ et al (1994) Enhancement of Biocontrol of Blue Mold with the Nutrient Analog 2-Deoxy-d-Glucose on Apples and Pears. Appl Environ Microbiol 60(8):2671-2676
  3. Valerio E et al (2008) Reappraisal of the Sporobolomyces roseus species complex and description of Sporidiobolus metaroseus sp. nov. Int J Syst Evol Microbiol 58:736–741
  4. Satoh K & Makimura K (2008) Sporobolomyces koalae sp. nov., a basidiomycetous yeast isolated from nasal smears of Queensland koalas kept in a Japanese zoological park. Int J Syst Evol Microbiol 58(12):2983-2986
  5. Sharma V et al (2006) Endogeneous endophthalmitis caused by Sporobolomyces salmonicolor. Eye (Lond) 20(8):945-946
  6. McNicholas S et al (2012) Sporobolomyces roseus in the cerebrospinal fluid of an immunocompetent patient--to treat or not to treat? J Med Microbiol 61(2):295-296
  7. Serena C et al (2005) In vitro interaction of micafungin with conventional and new antifungals against clinical isolates of Trichosporon, Sporobolomyces and Rhodotorula. J Antimicrob Chemother 55(6):1020-1023