The Arabian Gulf surrounding Qatar is an oligotrophic marine environment characterized by extreme conditions, such as increased water temperatures and high salinity compared to other semi-enclosed seas, such as the Mediterranean Sea. Thirty-six black yeast-like isolates were obtained from marine waters surrounding Qatar, representing 4% of all isolated yeasts. DNA sequence analysis of the internal transcribed spacers (ITS1, ITS2), the 5.8S rRNA gene, and the D1/D2 domains of the LSU rDNA identified 20 isolates as Hortaea werneckii, and 15 (75%) of them represent previously unknown genotypes with a wide NaCl tolerance at 37°C. In addition, 16 meristematic black yeast-like cultures were isolated that grew as multi-cellular bodies and reproduced by endoconidiation. Phylogenetic analysis based on the D1/D2 domains of LSU rDNA, partial sequences of the second largest subunit of RNA polymerase II (RPB2) and translation elongation factor 1-alpha (TEF) of selected representative strains of Dothideomycetes and of morphologically similar taxa, Pseudotaeniolina globosa and Trimmatostroma salinum, supported the proposal of meristematic black yeast-like cultures as a new species, Salinomyces qatarensis sp. nov., within Teratosphaeriaceae, Mycosphaerellales. The holotype is designated as CBS 150510, with ex-type strains EXF-15246 and QCC/Y38/18, and the species is registered in Mycobank as MB#848869. In addition, based on the above molecular analysis, a new combination was proposed for an euryhaline fungus from Mediterranean salterns, Trimmatostroma salinum, into the genus Verrucocladosporium as V. salinum, MB#856063. This study increases our knowledge of the distribution and genetic diversity of Hortaea werneckii, the etiological agent of tinea nigra. In addition, the description of S. qatarensis and the combination of euryhaline T. salinum to Verrucocladosporium provides support for halotolerance as one of the traits in Dothideomycetes.
Candida albicans causes life-threatening invasive infections that are hard to diagnose and treat, with drug resistance leading to treatment failure. The goal of this study was to develop VHH (single variable domain on a heavy chain) nanobodies to detect drug-resistant infections. Llamas were immunized with a mixture of heat killed and fixed C. albicans cells of different morphologies. Llama lymphocyte RNA was used to generate phage display libraries that were tested for binding to C. albicans cells or cell wall fractions, and single antibody domains were isolated. The libraries were panned against echinocandin-resistant C. albicans isolates and counter-selected against echinocandin-susceptible isolates with the aim of isolating binding domains specific for antigens on drug-resistant cells. Thirty diverse VHH nanobodies were selected, and binding characteristics were assessed via dose-response ELISA. Binding was tested against a variety of C. albicans isolates and other Candida species, indicating that the VHHs were specific for C. albicans. The VHH nanobodies were sorted into four distinct groups based on their binding patterns. Two of the groups bound preferentially to the yeast cell poles and hyphae, respectively. Nanobody binding to C. albicans deletion mutants was tested by fluorescence microscopy and ELISA to identify the antigen targets. VHH19 nanobody, belonging to the largest group, recognized the Als4 adhesin. VHH14 antibody in the hyphae-specific group recognized Als3. None of the isolated VHH nanobodies was selective for drug-resistant clinical isolates. Our data indicate that this approach can generate valuable single-domain antibodies specific to C. albicans proteins.IMPORTANCEThe human fungal pathogen Candida albicans causes a range of diseases from superficial mucosal infections such as oral and vaginal thrush to life-threatening, systemic infections. Accurate and rapid diagnosis of these infections remains challenging, and currently, there are no rapid ways to diagnose drug-resistant infections without performing drug susceptibility testing from blood culture, which can take several days. In this proof-of-concept study, we have generated a diverse set of single domain VHH antibodies (nanobodies) from llamas that recognize and bind specifically to C. albicans cell surface. The nanobodies were classified into four groups based on their binding patterns, for example, cell poles or hyphae. Specific nanobodies were verified as recognizing the important adhesin Als4 or the hyphae associated invasin Als3, respectively. The data validate the approach that small VHH antibody domains hold future promise for diagnostic applications and as probes to study the fungal cell surface.
Novel species of fungi described in this study include those from various countries as follows: Australia , Aschersonia mackerrasiae on whitefly, Cladosporium corticola on bark of Melaleuca quinquenervia , Penicillium nudgee from soil under Melaleuca quinquenervia , Pseudocercospora blackwoodiae on leaf spot of Persoonia falcata , and Pseudocercospora dalyelliae on leaf spot of Senna alata . Bolivia , Aspicilia lutzoniana on fully submersed siliceous schist in high-mountain streams, and Niesslia parviseta on the lower part and apothecial discs of Erioderma barbellatum onatwig. Brazil , Cyathus bonsai on decaying wood, Geastrum albofibrosum from moist soil with leaf litter, Laetiporus pratigiensis on a trunk of a living unknown hardwood tree species, and Scytalidium synnematicum on dead twigs of unidentified plant. Bulgaria , Amanita abscondita on sandy soil in a plantation of Quercus suber . Canada , Penicillium acericola on dead bark of Acer saccharum , and Penicillium corticola on dead bark of Acer saccharum . China , Colletotrichum qingyuanense on fruit lesion of Capsicum annuum . Denmark , Helminthosphaeria leptospora on corticioid Neohypochnicium cremicolor. Ecuador (Galapagos) , Phaeosphaeria scalesiae on Scalesia sp. Finland , Inocybe jacobssonii on calcareouss oils in dry forests and park habitats. France , Cortinarius rufomyrrheus on sandy soil under Pinus pinaster , and Periconia neominutissima on leaves of Poaceae . India , Coprinopsis fragilis on decaying bark of logs, Filoboletus keralensis on unidentified woody substrate, Penicillium sankaranii from soil, Physisporinus tamilnaduensis on the trunk of Azadirachta indica , and Poronia nagaraholensis on elephant dung. Iran , Neosetophoma fic on infected leaves of Ficus elastica . Israel , Cnidariophoma eilatica (incl. Cnidariophoma gen. nov.) from Stylophora pistillata . Italy , Lyophyllum obscurum on acidic soil. Namibia , Aureobasidium faidherbiae on dead leaf of Faidherbia albida , and Aureobasidium welwitschiae on dead leaves of Welwitschia mirabilis . Netherlands , Gaeumannomycella caricigena on dead culms of Carex elongata , Houtenomyces caricicola (incl. Houtenomyces gen. nov.) on culms of Carex disticha , Neodacampia ulmea (incl. Neodacampia gen. nov.) on branch of Ulmus laevis , Niesslia phragmiticola on dead standing culms of Phragmites australis , Pseudopyricularia caricicola on culms of Carex disticha , and Rhodoveronaea nieuwwulvenica on dead bamboo sticks. Norway , Arrhenia similis half-buried and moss-covered pieces of rotting wood in grass-grownpath. Pakistan , Mallocybe ahmadii on soil. Poland , Beskidomyces laricis (incl. Beskidomyces gen. nov.) from resin of Larix decidua ssp. polonica , Lapidomyces epipinicola from sooty mould community on Pinus nigra , and Leptographium granulatum from a gallery of Dendroctonus micans on Picea abies . Portugal , Geoglossum azoricum on mossy areas of laurel forest areas planted with Cryptomeria japonica , and Lunasporangiospora lusitanica from a biofilm covering a bio deteriorated limestone wall. Qatar , Alternaria halotolerans from hypersaline sea water, and Alternaria qatarensis from water sample collected from hypersaline lagoon. South Africa , Alfaria thamnochorti on culm of Thamnochortus fraternus , Knufia aloeicola on Aloe gariepensis , Muriseptatomyces restionacearum (incl. Muriseptatomyces gen. nov.) on culms of Restionaceae , Neocladosporium arctotis on nest of cases of bagworm moths( Lepidoptera, Psychidae ) on Arctotis auriculata , Neodevriesia scadoxi on leaves of Scadoxus puniceus , Paraloratospora schoenoplecti on stems of Schoenoplectus lacustris , Tulasnella epidendrea from the roots of Epidendrum × obrienianum , and Xenoidriella cinnamomi (incl. Xenoidriella gen. nov.) on leaf of Cinnamomum camphora . South Korea , Lemonniera fraxinea on decaying leaves of Fraxinus sp. frompond. Spain , Atheniella lauri on the bark of fallen trees of Laurus nobilis , Halocryptovalsa endophytica from surface-sterilised, asymptomatic roots of Salicornia patula , Inocybe amygdaliolens on soil in mixed forest, Inocybe pityusarum on calcareous soil in mixed forest, Inocybe roseobulbipes on acidic soils, Neonectria borealis from roots of Vitis berlandieri × Vitis rupestris , Sympoventuria eucalyptorum on leaves of Eucalyptus sp., and Tuber conchae fromsoil. Sweden , Inocybe bidumensis on calcareous soil. Thailand , Cordyceps sandindaengensis on Lepidoptera pupa, buried in soil, Ophiocordyceps kuchinaraiensis on Coleoptera larva, buried in soil, and Samsoniella winandae on Lepidoptera pupa, buriedinsoil. Taiwan region (China) , Neophaeosphaeria livistonae on dead leaf of Livistona rotundifolia . Türkiye , Melanogaster anatolicus on clay loamy soils. UK , Basingstokeomyces allii (incl. Basingstokeomyces gen. nov.) on leaves of Allium schoenoprasum . Ukraine , Xenosphaeropsis corni on recently dead stem of Cornus alba. USA , Nothotrichosporon aquaticum (incl. Nothotrichosporon gen. nov.) from water, and Periconia philadelphiana from swab of coil surface. Morphological and culture characteristics for these new taxa are supported by DNA barcodes.
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) is widely used in clinical laboratories for routine identification of bacteria and yeasts. However, methodological difficulties are still apparent when applied to filamentous fungi. The liquid cultivation method recommended by Bruker Daltonics GmbH for identification of filamentous fungi by MALDI-TOF MS is labour intensive and time-consuming. In this study, growth of Aspergillus species on different (porous) surfaces was investigated with the aim to develop a more reliable, quicker and less laborious identification method using MALDI-TOF MS. Mycelial growth without sporulation mimicking liquid cultivation and reliable MALDI-TOF MS spectra were obtained when A. fumigatus strains were grown on and in between a polycarbonate membrane filter on Sabouraud dextrose agar. A database of in-house reference spectra was created by growing Aspergillus reference strains (mainly focusing on sections Fumigati and Flavi) under these selected conditions. A test set of 50 molecularly identified strains grown under different conditions was used to select the best growth condition for identification and to perform an initial validation of the in-house database. Based on these results, the cultivation method on top of a polycarbonate filter proved to be most successful for species identification. This method was therefore selected for the identification of two sets of clinical isolates that mainly consisted of Aspergilli (100 strains originating from Indonesia, 70 isolates from Qatar). The results showed that this cultivation method is reliable for identification of clinically relevant Aspergillus species, with 67% and 76% correct identification of strains from Indonesia and Qatar, respectively. In conclusion, cultivation of Aspergilli on top of a polycarbonate filter showed improved results compared to the liquid cultivation protocol recommended by Bruker in terms of percentage of correct identification, ease of MSP creation, time consumption, cost and labour intensity. This method can be reliably applied for identification of clinically important Aspergilli and has potential for identification of other filamentous fungi.
This report is the first investigation of yeast biodiversity from the oligotrophic hypersaline coastal waters of the Arabian Gulf surrounding Qatar. Yeasts and yeast-like fungi, were cultured from seawater sampled at 13 coastal areas surrounding Qatar over a period of 2 years (December 2013–September 2015). Eight hundred and forty-two isolates belonging to 82 species representing two phyla viz., Ascomycota (23 genera) and Basidiomycota (16 genera) were identified by molecular sequencing. The results indicated that the coastal waters of the Qatari oligotrophic marine environment harbor a diverse pool of yeast species, most of which have been reported from terrestrial, clinical and aquatic sources in various parts of the world. Five species, i.e., Candida albicans, C. parapsilosis, C. tropicalis, Pichia kudriavzevii and Meyerozyma guilliermondii (n = 252/842; 30% isolates) are known as major opportunistic human pathogens. Fifteen species belonging to nine genera (n = 498/842; 59%) and 12 species belonging to seven genera (n = 459/842; 55%) are hydrocarbon degrading yeast and pollution indicator yeast species, respectively. Ascomycetous yeasts were predominant (66.38%; 559/842) as compared to their basidiomycetous counterparts (33.6%; 283/842). The most isolated yeast genera were Candida (28%; 236/842) (e.g., C. aaseri, C. boidinii, C. glabrata, C. intermedia, C. oleophila, C. orthopsilosis, C. palmioleophila, C. parapsilosis, C. pseudointermedia, C. rugopelliculosa, C. sake, C. tropicalis and C. zeylanoides), Rhodotorula (12.7%; 107/842), Naganishia (8.4%; 71/842), Aureobasidium (7.4%; 62/842), Pichia (7.3%; 62/842), and Debaryomyces (6.4%; 54/842). A total of eleven yeast species ( n = 38) isolated in this study are reported for the first time from the marine environment. Chemical testing demonstrated that seven out of the 13 sites had levels of total petroleum hydrocarbons (TPH) ranging from 200 to 900 µg/L, whereas 6 sites showed higher TPH levels (> 1000–21000 µg/L). The results suggest that the yeast community structure and density are impacted by various physico-chemical factors, namely total organic carbon, dissolved organic carbon and sulphur.
During a study of yeast diversity in marine waters of the Arabian Gulf surrounding Qatar, 30 strains were isolated that represent a novel species of Kondoa. The isolates were obtained from five locations along the Qatari coast. Species identifications were based on sequence analysis of the internal transcribed spacer (ITS) regions and D1/D2 domains of the large subunit (LSU) rRNA gene. Five strains were selected for further study. The novel species was closely related to Kondoa aeria (CBS 8352T) and Kondoa malvinella (CBS 6082T) but differed from the two species by 5.6 % sequence divergence (16 substitutions and 14 gaps) in the ITS region. On the basis of D1/D2 domains of the LSU rRNA gene, the novel species differed from K. aeria by only >0.35 % sequence divergence (2 substitutions and 0 gaps) and 1.5 % sequence divergence (9 substitutions and 1 gap) to that of K. malvinella. Although the novel species showed a close similarity in the D1/D2 domains to K. aeria (CBS 8352T), based on the significant differences (16 substitutions) in ITS regions and on the basis of physiological and biochemical tests, viz ability to grow at 35 °C, and inability to assimilate, sucrose, raffinose, d,l-lactate, succinate, citrate and nitrite, these strains are considered as novel species of Kondoa. The species name of Kondoa qatarensis f.a., sp. nov. is proposed with specimen 2Y109 as the holotype.
Two strains, 1Y129 and 3Y383, which represent a single novel anamorphic yeast species, were isolated from the Arabian Gulf surrounding Qatar. The two strains have identical sequences in the D1/D2 domains of the large subunit (LSU) and the internal transcribed spacer (ITS) regions of the rRNA gene. On the basis of this sequence analysis the two strains were found to be closely related to Cystobasidium slooffiae CBS5706T with 97. 3 % nucleotide substitutions (12 nt; four gaps) in D1/D2 regions of the LSU rRNA and 97.0 % nucleotide substitutions (14 nt; two gaps) in ITS regions. In contrast to Cystobasidium halotolerans sp. nov., the related species Cystobasidium slooffiae, Cystobasidium minutum and Cystobasidium fimetarium were unable to assimilate d-galactose, soluble starch, galactitol, methanol or nitrate, and grew at 37 °C. The name proposed for this undescribed species is Cystobasidium halotolerans sp. nov. The ex-type strain is QCC/Y31/17 (=MUCL057192=CGMCC2.5570).
The Arabian Gulf surrounding Qatar is distinct from other marine ecosystems due to its high salinity (35-75 PSU) and extreme water temperature fluctuations (11-40 °C). Furthermore, in the last decade, Qatar has been witnessing an industrial boom as well as extensive infrastructure construction activities. Marine micro-organisms, including fungi, remain largely unexplored in the Arabian Gulf. During a 3 year study, we investigated the diversity of marine fungi in coastal waters around Qatar. As a result, two new Toxicocladosporium species were isolated from the Qatari marine environment. Molecular and phylogenetic analyses of rRNA gene sequences of five loci, namely the internal transcribed spacer 1 and 2 regions and the D1/D2 domains of the large subunit rRNA, actin, RNA polymerase second largest subunit and beta-tubulin genes, were used to confirm the identity of the novel species for which we propose the names Toxicocladosporium aquimarinum sp. nov. and Toxicocladosporium qatarense sp. nov.
The hypersaline Inland Sea in Qatar constitutes a unique ecosystem characterized by salinities up to saturation, extreme temperature fluctuations, and limited rainfall. To reveal the fungal diversity of this environment, we isolated fungi from water samples collected at the Inland Sea. Taxonomic identification of the isolates was done via DNA barcoding of the ITS1 and ITS2 ribosomal DNA (rDNA) domains and the D1/D2 domains of the nuclear large subunit rDNA. Additional genes, including glyceraldehyde-3-phosphate dehydrogenase (gapdh) and translation elongation factor 1-alpha (tef1), were included for isolates of Alternaria, actin (Act) for Cladosporium, part of the beta-tubulin (BenA) and calmodulin (CaM) genes for Aspergillus and Penicillium. In total, 159 fungal isolates, including 85 Ascomycota and 74 Basidiomycota, were obtained from the water samples collected during four samplings in the winter and summer seasons. About 14% (22/159) of the strains, presumably novel species, were preliminarily identified to the genus level. This is the first report highlighting the diversity of fungi from the hypersaline Inland Sea in Qatar.
Cystic fibrosis (CF) patients are colonized with a multitude of bacteria and fungi. From respiratory samples of two CF patients in our institute, a difficult to identify yeast was isolated repeatedly. This yeast was eventually identified as Cutaneotrichosporon (Cryptococcus) cyanovorans by internal transcribed spacer (ITS) and ribosomal large subunit (LSU) sequencing. C. cyanovorans is a basidiomycetous yeast originally reported as environmental isolate from South African soil and has not been described before as clinical isolate from CF patients.
Background and Purpose: Vulvovaginal candidiasis (VVC) is a common problem in women. The purpose of this study was to identify Candida isolates by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) from women with vulvovaginitis that were referred to Ghaem Hospital, Mashhad, Iran. Materials and Methods: This study was conducted on 65 clinical samples isolated from women that were referred to Ghaem Hospital. All specimens were identified using phenotyping techniques, such as microscopy and culture on Sabouraud dextrose agar and corn meal agar. In addition, all isolates were processed for MALDI-TOF MS identification. Results: Out of the 65 analyzed isolates, 61 (94%) samples were recognized by MALDI-TOF MS. However, the remaining four isolates (6%) had no reliable identification. According to the results, C. albicans (58.5%) was the most frequently isolated species, followed by C. tropicalis (16.9%), C. glabrata (7.7%), C. parapsilosis (7.7%), and guilliermondii (3.1%). Conclusion: As the findings indicated, MALDI TOF MS was successful in the identification of clinical Candida species. C. albicans was identified as the most common Candida species isolated from the women with VVC. Moreover, C. tropicalis was the most common species among the non-albicans Candida species.
Two yeast strains (INY29 and INY13) representing a novel yeast species were isolated from the hypersaline marine environment of the Inland Sea, Qatar. Phylogenetic analysis based on the D1/D2 domains of the large subunit (LSU) regions and internal transcribed spacer (ITS1 and ITS2) regions showed that the two strains represent a single species in the genus Naganishia that is distinct from other species. These two strains were classified as members of the genus Naganishia and clustered in a strongly supported clade represented by Naganishia albidus in the Filobasidiales order in the phylogenetic tree drawn from ITS and D1/D2 sequences. The novel species was most closely related to the type strain of Naganishia cerealis but the two species differed by 1% sequence divergence (four substitutions and one gap) in the D1/D2 domains and (five substitutions and one gap) in the ITS regions. In contrast to the closest relative, N. cerealis, the novel yeast species assimilated melibiose, glycerol, meso-erythritol, DL-lactate, methanol, propane 1-2-diol, butane 2-3-diol, and grew at 35 degrees C. The name Naganishia qatarensis sp. nov. is proposed to accommodate these strains, with INY29 as the holotype.
Cystic fibrosis (CF) patients are colonized by a multitude of bacteria and fungi.In our institute, respiratory specimens from a large part of the Dutch CF population is frequently cultured.Here, we report the repeated isolation of Cutaneotrichosporon (Cryptococcous) cyanovorans from the airways of two CF patients.C. cyanovorans was described in 2012 as a basidiomycetous yeast isolated from South African soil, contaminated with cyanide. 1
The present study introduces seven new species, one new combination, one new variety and several interesting taxonomical notes and/or geographical records. Most of the new taxa are Ascomycetes, but the study also includes a new variety of a Basidiomycete. Novel species include Gyromitra khanspurensis (Discinaceae, Pezizales, Pezizomycetes) from Pakistan growing near Cedrus deoadara and Paramyrothecium guiyangense and Paramyrothecium verruridum (Stachybotriaceae, Hypocreales, Sordariomycetes) both isolated from soil in China. New species from South Africa are Sclerostagonospora elegiae on culm litter of Elegia equisetacea, Sclerostagonospora fusiformis on culm litter of Thamnochortus spicigerus, Sclerostagonospora pinguis on culm litter of Cannomois virgata and Sclerostagonospora sulcata on culm litter of Ischyrolepis subverticellata (Phaeosphaeriaceae, Pleosporales, Dothideomycetes). Hapalocystis berkeleyi var. kickxii with its basionym Hypoxylon kickxii is shown to be a taxon on species level and thus recombined as Hapalocystis kickxii (Sydowiellaceae, Diaporthales, Sordariomycetes), and it is lecto- and epitypified. The new variety Pluteus romellii var. luteoalbus (Pluteaceae, Agaricales, Agaricomycetes) growing on a mossy fallen stem of a deciduous tree is described from Czech Republic. Cortinarius scaurocaninus (Cortinariaceae, Agaricales, Agaricomycetes) is new for Austria, Humicola grisea (Chaetomiaceae, Sordariales, Sordariomycetes) is an interesting new record for Chile. Two taxa are reported as new for Turkey: the lichenicolous fungus Opegrapha parasitica (Opegraphaceae, Arthoniales, Arthoniomycetes) growing partly immersed in the thallus of Aspicilia and the lichen Rinodina zwackhiana (Physciaceae, Teloschistales, Lecanoromycetes) from calcareous rock. Finally, Xerula strigosa (Physalacriaceae, Agaricales, Agaricomycetes), described from China, is confirmed to be present also in Pakistan.
Since food spoilage by yeasts causes high economic losses, fast and accurate identifications of yeasts associated with food and food-related products are important for the food industry. In this study the efficiency of the matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify food related yeasts was evaluated.A CBS in-house MALDI-TOF MS database was created and later challenged with a blinded test set of 146 yeast strains obtained from food and food related products. Ninety eight percent of the strains were correctly identified with log score values>1.7. One strain, Mrakia frigida, gained a correct identification with a score value<1.7. Two strains could not be identified at first as they represented a mix of two different species. These mixes were Rhodotorula babjevae with Meyerozyma caribbica and Clavispora lusitaniae with Debaryomyces hansenii. After separation, all four species could be correctly identified with scores>1.7. Ambiguous identifications were observed due to two incorrect reference mass spectra's found in the commercial database BDAL v.4.0, namely Candida sake DSM 70763 which was re-identified as Candida oleophila, and Candida inconspicua DSM 70631 which was re-identified as Pichia membranifaciens. MALDI-TOF MS can distinguish between most of the species, but for some species complexes, such as the Kazachstania telluris and Mrakia frigida complexes, MALDI-TOF MS showed limited resolution and identification of sibling species was sometimes problematic. Despite this, we showed that the MALDI-TOF MS is applicable for routine identification and validation of foodborne yeasts, but a further update of the commercial reference databases is needed.
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. 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.
Opportunistic infections due to Candida species occur frequently in intensive care settings. We investigated the prevalence of Candida species among 65 clinical specimens obtained from 200 cancer patients by phenotypic and molecular (ITS sequencing and AFLP) methods. Among the 65 yeast isolates, Candida albicans was the most commonly isolated species (n = 34, 52.3%), whereas other Candida species comprised 47.7% (n = 31) and consisted of Candida glabrata (n = 14, 21.5%), Candida tropicalis (n = 5, 7.7%) and uncommon Candida species (n = 12, 18.5%) such as Candida pelliculosa (n = 3, 4.6%), Pichia kudriavzevii (= Candida krusei, n = 2, 3.1%), Candida orthopsilosis (n = 2, 3.1%), Candida parapsilosis (n = 1, 1.5%), Candida infanticola (n = 2, 3.1%), Candida spencermartinsiae (n = 1, 1.5%), and Kluyveromyces marxianus (=Candida kefyr, n = 1, 1.5%). Candida infanticola and Candida spencermartinsiae were recovered from oral lesions of cancer patients. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) easily confirmed these isolates as less common Candida isolates (4.6%). The in vitro antifungal susceptibilities of C. spencermartinsiae and the two strains of C. infanticola were determined according to CLSI guidelines (M27-A3). MIC results among these isolates showed they were susceptible to isavuconazole, posaconazole and voriconazole, however, fluconazole and caspofungin had high MIC values. These Candida species that may occur more commonly in infections remain unnoticed using commonly used phenotypical methods in routine microbiology laboratories. MALDI-TOF MS proved to be a more fast and robust diagnostic technique for identification of the yeasts isolated from different clinical specimens of cancer patients.