Phylogenetic analysis of 11 genetic loci and results from many genotyping studies revealed significant genetic diversity with the pathogenic Cryptococcus gattii/Cryptococcus neoformans species complex. Genealogical concordance, coalescence-based, and species tree approaches supported the presence of distinct and concordant lineages within the complex. Consequently, we propose to recognize the current C. neoformans var. grubii and C. neoformans var. neoformans as separate species, and five species within C. gattii. The type strain of C. neoformans CBS132 represents a serotype AD hybrid and is replaced. The newly delimited species differ in aspects of pathogenicity, prevalence for patient groups, as well as biochemical and physiological aspects, such as susceptibility to antifungals. MALDI-TOF mass spectrometry readily distinguishes the newly recognized species.

dThe Candida haemulonii species complex is currently known as C. haemulonii groups I and II. Here we describe C. haemulonii group II as a new species, Candida duobushaemulonii sp. nov., and C. haemulonii var. vulnera as new a variety of C. haemulonii group I using phenotypic and molecular methods. These taxa and other relatives of C. haemulonii (i.e., Candida auris and Candida pseudohaemulonii) cannot be differentiated by the commercial methods now used for yeast identification. Four isolates (C. haemulonii var. vulnera) differed from the other isolates of C. haemulonii in the sequence of the internal transcribed spacer (ITS) regions of the nuclear rRNA gene operon. The new species and the new variety have a multiresistant antifungal profile, which includes high MICs of amphotericin B (geometric mean MIC, 1.18 mg/liter for C. haemulonii var. vulnera and 2 mg/liter for C. duobushaemulonii sp. nov) and cross-resistance to azole compounds. Identification of these species should be based on molecular methods, such as sequence analysis of ITS regions and matrix-assisted laser desorption ionization-time of flight mass spectrometry. Candida and Aspergillus species are the most common causes of invasive fungal infections in immunocompromised individuals, but besides these fungi, many other yeast species and filamentous fungi can be pathogenic in such individuals (7). The list of reported species that cause human infection is constantly growing, partly because of recent advances in molecular tools and diagnostics. Thus, new clinically relevant species such as Candida metapsilosis, Candida orthopsilosis, Candida bracariensis, and Candida nivariensis, have been described recently (1,5,39).Candida haemulonii (van Uden and Kolipinsky) S. A. Meyer and D. Yarrow (41) (syn. Torulopsis haemulonii) is one of the rare yeast species that can be isolated from human clinical sources. The species originally described was from the gut of a blue-striped grunt fish (Haemulon scirus) in 1962 (40). The first isolation of this yeast from a human, i.e., from the blood of a patient with renal failure, was reported by Lavarde et al. (22). Since then, several cases of infections due to this yeast have been described in the literature, varying from superficial to deep infections. Cases of catheter-related fungemia (18), bloodstream infections (30,34), and osteitis (6) and outbreaks in intensive care units (16) have been reported recently. The species has also been isolated from toenails of diabetic patients (13). Noteworthy is the susceptibility profile of this yeast, which shows high MICs of amphotericin B (AMB) and fluconazole (FLC) (ranges, 0.5 to 32 and 4 to Ͼ64 mg/liter, respectively), which can hinder the management of patients with deep infections caused by this yeast. This antifungal profile has often been associated with clinical failure (6,16,17,30,34).The C. haemulonii species complex was further studied by Lehman et al. in 1993 (24). They studied 25 strains from different geographic origins and clinical sources and described two gene...

Cryptococcosis is a major fungal disease caused by members of the Cryptococcus gattii and Cryptococcus neoformans species complexes. After more than 15 years of molecular genetic and phenotypic studies and much debate, a proposal for a taxonomic revision was made.

Detection, identification and classification of yeasts have undergone a major transformation in the last decade and a half following application of gene sequence analyses and genome comparisons. Development of a database (barcode) of easily determined DNA sequences from domains 1 and 2 (D1/D2) of the nuclear large subunit rRNA gene and from ITS now permits many laboratories to identify species quickly and accurately, thus replacing the laborious and often inaccurate phenotypic tests previously used. Phylogenetic analysis of gene sequences is leading to a major revision of yeast systematics that will result in redefinition of nearly all genera. This new understanding of species relationships has prompted a change of rules for naming and classifying yeasts and other fungi, and these new rules are presented in the recently implemented International Code of Nomenclature for algae, fungi, and plants (Melbourne Code). The use of molecular methods for species identification and the impact of Code changes on classification will be discussed, as will use of phylogeny for prediction of biotechnological applications.

No abstract

The Middle East epidemiology of candidemia has a unique species distribution pattern distinct from other parts of the globe. High mortality rates were observed among pediatric (<1 year of age) and elderly patients (>60 years of age). All strains were susceptible to isavuconazole. All isolates of C.glabrata were resistant to caspofungin based on M27 S4. MALDI-TOF MS is a highly useful method for the routine identification of yeast isolates in clinical setting to achieve successful therapeutic treatment.

An interlaboratory study using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) to determine the identification of clinically important yeasts (n ‫؍‬ 35) was performed at 11 clinical centers, one company, and one reference center using the Bruker Daltonics MALDI Biotyper system. The optimal cutoff for the MALDI-TOF MS score was investigated using receiver operating characteristic (ROC) curve analyses. The percentages of correct identifications were compared for different sample preparation methods and different databases.

Eleven uncommon yeast species that are associated with high mortality rates irrespective of antifungal therapy were isolated from 17/187 (201 episodes) pediatric and elderly patients with fungemia from Qatar. The samples were taken over a 6-year period (January 2004-December 2010). Isolated species included Kluyveromyces marxianus, Lodderomyces elongisporus, Lindnera fabianii, Candida dubliniensis, Meyerozyma guilliermondii, Candida intermedia, Pichia kudriavzevii, Yarrowia lipolytica, Clavispora lusitaniae, Candida pararugosa, and Wickerhamomyces anomalus. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry provided correct identifications compared with molecular analysis testing of the same isolates. Low minimal inhibitory concentrations were found when isavuconazole and voriconazole were used for all uncommon yeast species evaluated in this study. Resistance to antifungal drugs was low and remained restricted to a few species.