Malassezia furfur from birds.

F. Javier Cabañes*, Laura Puig, M. Rosa Bragulat,  Gemma Castellá, 
Veterinary Mycology Group, Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain.

E-mail: javier.cabanes@uab.es
Objectives

Although M. furfur (sensu stricto) is a common member of the human skin microbiota, it has been also reported from the skin of various animal species (14). In this study we have examined some M. furfur strains from birds, confirmed their identity by DNA sequencing and compared with other M. furfur strains from other origins.
Methods
Physiological characterization was based on the splitting of esculin due to β-glucosidase activity, catalase reaction and growth at 37ºC, 40ºC and 42ºC on mDA. The ability to assimilate Tween 20, Tween 40, Tween 60, Tween 80 and Cremophor EL was tested with the Tween diffusion test on SGA and yeast nitrogen base agar (YNBA) (2). 
Internal transcribed spacer (ITS) region (including the genes ITS1, 5.8S rRNA and ITS2), large subunit of the ribosomal RNA (LSU) region, and β-tubulin genes were amplified and sequenced.
Results
These strains were able to grow on mDA from 32 to 42ºC. The catalase reaction and the β-glucosidase activity were positive. On SGA and YNBA, although some intermediate assimilation patterns were found, all the strains from birds were able to grow around the different lipids assayed. Sequencing of the ITS and LSU rRNA regions and -tubulin genes confirmed that the lipid-dependent strains from birds belonged to the species M. furfur.

 In the LSU phylogenetic tree, the strains from birds appear grouped in one clade with low bootstrap support. LSU sequences differences among M. furfur strains analysed were less than 1%, not exceeding the within-species variation generally observed to occur in Malassezia spp.

However, the phylogenetic trees of both ITS and β-tubulin sequences of M. furfur strains analysed revealed two strongly supported clades. One clade included strains isolated from humans and domestic animals and the other clade comprised the strains from wild animals including all the strains from birds.

Conclusion
The identity of the strains from birds as M. furfur was confirmed by DNA sequencing (M. furfur Med Mycol 2018). In this study, we have proven that M. furfur can be found on a broad spectrum of animals, like wild birds held in captivity. Future studies will probably widen even more the number of niches that are colonized by this species.