Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/13/2004
Publication Date: 12/1/2005
Citation: Kurtzman, C.P., Robnett, C.J., Ward, J.N., Brayton, C., Gorelick, P., Walsh, T.J. 2005. Multigene phylogenetic analyses of pathogenic Candida species in the Kazachstania (Arxiozyma) telluris complex and the description of their ascosporic states as Kazachstania bovina sp. nov., K. heterogenica sp. nov., K. pintolopesii sp. nov., and K. slooffiae sp. nov. Journal of Clinical Microbiology. 43(1):101-111. Interpretive Summary: Laboratory mice used at the National Institutes of Health, and at several other clinical research laboratories, have been devastated by a widespread yeast infection. Representative isolates of the pathogenic yeast were sent to NCAUR by NIH for identification. Through application of the species-specific gene sequence database developed at NCAUR, the yeasts isolates were identified as Candida pintolopesii. A molecular comparison of additional isolates of this species maintained in the ARS Culture Collection revealed that the isolates actually represent a complex of five closely related species. Furthermore, the ascosporic sexual state was found in one or more strains of each of the four newly recognized species, allowing their description in the ascospore producing genus Kazachstania. This work identified the yeast pathogenic to mice, detected four new ascosporic species and showed that the infective yeasts were contaminants of bedding material used for the mice.
Technical Abstract: A yeast causing widespread infection of laboratory mice was identified from 26S rDNA sequences as Candida pintolopesii. To determine the relationship of C. pintolopesii with other members of the Kazachstania (Arxiozyma) telluris species complex, nucleotide sequences from domains D1/D2 26S rDNA, mitochondrial small subunit rDNA and RNA polymerase II were phylogenetically analyzed resolving the 48 strains examined into five closely related species: K. telluris, Candida bovina, C. pintolopesii, C. slooffiae, and a previously unknown species. One or more strains of each of the latter four species formed an ascosporic state much like that of K. telluris. To taxonomically place these ascosporogenous strains, it is proposed that they be assigned to the teleomophic genus Kazachstania as K. bovina (type strain NRRL Y-7283, CBS 9732, from the nasal passage of a pigeon), K. heterogenica (type strain NRRL Y-27499, CBS 2675, from rodent feces), K. pintolopesii (type strain NRRL Y-27500, CBS 2985, from peritoneal fluid, dead guinea pig), and K. slooffiae (type strain NRRL YB-4349, CBS 9733, from a horse caecum). On the basis of multigene sequence analyses, K. heterogenica appears to be a hybrid of K. pintolopesii and a presently unknown species. With the exception of K. bovina, the phylogenetically defined species show a moderate degree of host specificity.