Importance of Resolving Fungal Nomenclature: the Case of Multiple Pathogenic Species in the Cryptococcus Genus.

Ferry Hagen ,Pojana Sriburee ,Katrien Lagrou ,H Thorsten Lumbsch ,Ziauddin Khan ,Rama Falk ,Sébastien Bertout ,Wanqing Liao ,Patricia Fernanda Herkert ,Pedro W Crous ,Consuelo Ferrer Rodríguez ,Valentina Arsic Arsenijević ,Kantarawee Khayhan ,Bart Theelen ,Retno Wahyuningsih ,Josepa Gené ,Kirsten Nielsen ,Mara R Diaz ,F Javier Cabañes ,Josep Guarro ,M.r Bragulat ,Ana Espinel-Ingroff ,Ana Sampaio ,Hamed Fakhim ,Weihua Pan ,Arunaloke Chakrabarti ,R Blake Billmyre ,Manuel Sánchez ,Brunella Posteraro ,Mauricio Carbia ,Anna Kolecka ,Cletus P Kurtzman ,Wenjie Fang ,Jacques F Meis ,Sudha Chaturvedi ,Takashi Sugita ,María Teresa Illnait-Zaragozí ,Rok Tomazin ,Itzhack Polacheck ,Flávio De Queiroz Telles Filho ,María Francisca Colom ,Marina Pekmezović ,Ping Wang ,Oliver A Cornely ,Masako Takashima ,Hamid Badali ,James A Fraser ,Anuradha Chowdhary ,Tinashe K Nyazika ,Saad J Taj-Aldeen ,Min Chen ,Paul E Verweij ,María Soledad Cuétara ,Alexander Idnurm ,Orazio Romeo ,John W Taylor ,Carlos Eduardo Blanco Linares ,Teun Boekhout

doi:10.1128/msphere.00238-17

Abstract

Cryptococcosis is a major fungal disease caused by members of the Cryptococcus gattii and Cryptococcus neoformans species complexes. After more than 15years of molecular genetic and phenotypic studies and much debate, a proposal for a taxonomic revision was made. The two varieties within C.neoformans were raised to species level, and the same was done for five genotypes within C.gattii. In a recent perspective (K. J. Kwon-Chung et al., mSphere 2:e00357-16, 2017, https://doi.org/10.1128/mSphere.00357-16), it was argued that this taxonomic proposal was premature and without consensus in the community. Although the authors of the perspective recognized the existence of genetic diversity, they preferred the use of the informal nomenclature "C. neoformans species complex" and "C. gattii species complex." Here we highlight the advantage of recognizing these seven species, as ignoring these species will impede deciphering further biologically and clinically relevant differences between them, which may in turn delay future clinical advances.

Highlights

Cryptococcosis is a major fungal disease caused by members of the Cryptococcus gattii and Cryptococcus neoformans species complexes
In 2002, C. neoformans var. gattii was raised to species level, and the name C. gattii was given nomenclatural priority over the older name C. bacillisporus [14]
On the basis of four genes, it was calculated that C. neoformans/C. deneoformans separated from the C. gattii species complex 37 million years ago, C. neoformans and C. deneoformans separated 18.5 million years ago, and C. gattii and C. bacillisporus separated 9.5 million years ago [31]. These divergence times might be older, as recent calculations based on genomic data fine-tuned the divergence time of the C. neoformans/C. deneoformans and the C. gattii species complex to 80 to 100 million years ago [32]

Summary

Introduction

Cryptococcosis is a major fungal disease caused by members of the Cryptococcus gattii and Cryptococcus neoformans species complexes. The phenotypic heterogeneity within the Cryptococcus neoformans species complex has been known for many years, beginning with the identification of four serotypes, serotypes A to D [6, 7]. The genus Cryptococcus in its current concept contains the dimorphic yeasts C. amylolentus, C. bacillisporus, C. decagattii, C. deneoformans, C. deuterogatttii, C. neoformans, C. gattii, and C. tetragattii [21, 22] and the filamentous species C. depauperatus and C. luteus [8, 22, 28, 29].

Results

Conclusion