Species of the genus Prototheca are achlorophyllous algae and ubiquitous in nature, and so far, six species have been listed in this genus: Prototheca wickerhamii, Prototheca zopfii, Prototheca blaschkeae, Prototheca cutis, Prototheca stagnora and Prototheca ulmea. A strain of the genus Prototheca, IFM 53848T, was isolated in Japan from a patient with systemic protothecosis and had been designated P. wickerhamii. Our previous study, by using PCR analysis, revealed that its SSU rRNA gene (rDNA) was distinctively larger than that of P. wickerhamii and other species of the genus Prototheca. In this study, molecular analysis showed that the exceptionally large SSU rDNA of IFM 53848T contains four group I introns. The morphology of IFM 53848T was indistinguishable from those of P. wickerhamii or P. cutis, and phylogenetic analyses, based on the sequences of the SSU rDNA exons and the D1/D2 region of the large subunit rDNA, indicated that IFM 53848T was closely related to P. cutis. On the other hand, unlike P. cutis, IFM 53848T failed to assimilate fructose or lysine and grew well at higher temperatures of up to 42 °C. In addition, the nucleotide sequence of the ribosomal internal transcribed spacer and the matrix assisted laser desorption ionization time-of-flight mass spectrometry profile of IFM 53848T were clearly distinct from those of P. cutis. The results strongly suggest that IFM 53848T represents a novel species, and so the seventh member of the genus Prototheca, which we have named Prototheca miyajii sp. nov. The unique characteristics of the strain may provide useful insights into the systematic taxonomy of the genus Prototheca.
AhrholdtJ., MurugaiyanJ., StraubingerR. K., JagielskiT., RoeslerU.2012; Epidemiological analysis of worldwide bovine, canine and human clinical Prototheca isolates by PCR genotyping and MALDI-TOF mass spectrometry proteomic phenotyping. Med Mycol 50:234–243 [View Article][PubMed]
BhattacharyaD., FriedlT., DambergerS.1996; Nuclear-encoded rDNA group I introns: origin and phylogenetic relationships of insertion site lineages in the green algae. Mol Biol Evol 13:978–989 [View Article][PubMed]
BurkeJ. M., BelfortM., CechT. R., DaviesR. W., SchweyenR. J., ShubD. A., SzostakJ. W., TabakH. F.1987; Structural conventions for group I introns. Nucleic Acids Res 15:7217–7221 [View Article][PubMed]
CechT. R., DambergerS. H., GutellR. R.1994; Representation of the secondary and tertiary structure of group I introns. Nat Struct Biol 1:273–280 [View Article][PubMed]
GuéhoE., KurtzmanC. P., PetersonS. W.1990; Phylogenetic relationships among species of Sterigmatomyces and
Fellomyces as determined from partial rRNA sequences. Int J Syst Bacteriol 40:60–65 [View Article][PubMed]
HiroseN., NishimuraK., Inoue-SakamotoM., MasudaM.2013; Ribosomal internal transcribed spacer of Prototheca wickerhamii has characteristic structure useful for identification and genotyping. PLoS One 8:e81223 [View Article][PubMed]
JánosiS., RátzF., SzigetiG., KulcsárM., KerényiJ., LaukóT., KatonaF., HuszeniczaG.2001; Review of the microbiological, pathological, and clinical aspects of bovine mastitis caused by the alga Prototheca zopfii
. Vet Q 23:58–61 [View Article][PubMed]
MachouartM., LacroixC., BuiH., Feuilhade de ChauvinM., DerouinF., LorenzoF.2004; Polymorphisms and intronic structures in the 18S subunit ribosomal RNA gene of the fungi Scytalidium dimidiatum and Scytalidium hyalinum. FEMS Microbiol Lett 238:455–467 [View Article][PubMed]
Machouart-DubachM., LacroixC., VauryC., de ChauvinM. F., BellannéC., DerouinF., LorenzoF.2002; Nucleotide structure of the Scytalidium hyalinum and Scytalidium dimidiatum 18S subunit ribosomal RNA gene: evidence for the insertion of a group IE intron in the rDNA gene of S. dimidiatum
. FEMS Microbiol Lett 208:187–196 [View Article][PubMed]
MatsudaT., MatsumotoT.1992; Protothecosis: a report of two cases in Japan and a review of the literature. Eur J Epidemiol 8:397–406 [View Article][PubMed]
MurugaiyanJ., AhrholdtJ., KowbelV., RoeslerU.2012; Establishment of a matrix-assisted laser desorption ionization time-of-flight mass spectrometry database for rapid identification of infectious achlorophyllous green micro-algae of the genus Prototheca
. Clin Microbiol Infect 18:461–467 [View Article][PubMed]
RoeslerU., MöllerA., HenselA., BaumannD., TruyenU.2006; Diversity within the current algal species Prototheca zopfii: a proposal for two Prototheca zopfii genotypes and description of a novel species. Prototheca blaschkeae sp. nov. Int J Syst Evol Microbiol 56:1419–1425 [View Article][PubMed]
StennerV. J., MackayB., KingT., BarrsV. R., IrwinP., AbrahamL., SwiftN., LangerN., BernaysM., other authors. 2007; Protothecosis in 17 Australian dogs and a review of the canine literature. Med Mycol 45:249–266 [View Article][PubMed]
TamuraK.1992; Estimation of the number of nucleotide substitutions when there are strong transition-transversion and G+C-content biases. Mol Biol Evol 9:678–687[PubMed]
ToddJ. R., KingJ. W., OberleA., MatsumotoT., OdakaY., FowlerM., PoreR. S., ShahanT. A., YinL., SanusiI. D.2012; Protothecosis: report of a case with 20-year follow-up, and review of previously published cases. Med Mycol 50:673–689 [View Article][PubMed]
von BergenM., EidnerA., SchmidtF., MurugaiyanJ., WirthH., BinderH., MaierT., RoeslerU.2009; Identification of harmless and pathogenic algae of the genus Prototheca by MALDI-MS. Proteomics Clin Appl 3:774–784 [View Article][PubMed]
WhiteT.J.,, BrunsT., LeeS., TaylorJ. W.1990; Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In PCR Protocols: A Guide to Methods and Applications pp 315–322Edited byInnisM. A., GelfandD. H., SninskyJ. J., WhiteT. J. New York: [View Article] Academic Press;
WirthH., von BergenM., MurugaiyanJ., RöslerU., StokowyT., BinderH.2012; MALDI-typing of infectious algae of the genus Prototheca using SOM portraits. J Microbiol Methods 88:83–97 [View Article][PubMed]
XiaoL., EscalanteL., YangC., SulaimanI., EscalanteA. A., MontaliR. J., FayerR., LalA. A.1999; Phylogenetic analysis of Cryptosporidium parasites based on the small-subunit rRNA gene locus. Appl Environ Microbiol 65:1578–1583[PubMed]
XuC., WangC., SunX., ZhangR., GleasonM. L., EijiT., SunG.2013; Multiple group I introns in the small-subunit rDNA of Botryosphaeria dothidea: implication for intraspecific genetic diversity. PLoS One 8:e67808 [View Article][PubMed]
YamadaN., YoshidaY., OhsawaT., TakaharaM., MorinoS., YamamotoO.2010; A case of cutaneous protothecosis successfully treated with local thermal therapy as an adjunct to itraconazole therapy in an immunocompromised host. Med Mycol 48:643–646 [View Article][PubMed]