Phylogeny and taxonomy of meristematic rock-inhabiting black fungi in the Dothideomycetes based on multi-locus phylogenies

The last decade has revealed an unexpected fungal diversity associated with natural rocks,often collected in environments influenced by harsh climatic conditions.Yet the phylogenetic affiliations and the taxonomy of many of these extreme fungi,mainly within Dothideomycetes,the largest class of Ascomycota,have only partially been described.In the present study we confirm that most rock inhabiting-fungi(RIF)are highly polyphyletic among Dothideomycetidae,mainly within the order Capnodiales,an order otherwise incorporating several families of major plant pathological importance.Novel taxa were identified within the two major and distinct clades of Teratosphaeriaceae,both comprising meristematic black fungi.Thirty one novel species and 13 new genera are proposed,based on ITS and partial nucLSU,RPB2 and BT2 sequences.

Diversity and delimitation of Rhizopus microsporus

Rhizopus microsporus has been used for centuries in the production of oriental fermented foods,but the species is also known as a toxin producer and from severe human infections.To study the diversity and species delimitation of Rhizopus microsporus,48 isolates from the reference collection of the CBS-KNAW Fungal Biodiversity Centre,comprising nine environmental,ten clinical,and 23 foodborne strains,in addition to six strains from unknown sources and representing all existing varieties of the species,were examined.Sequence diversity was based on the internal transcribed spacer(ITS),and on a part of the actin(ACT)and translation elongation factor 1-α(TEF)genes.Differences in physiological properties were assessed including temperature relationships.Spore morphology was studied,mating type tests were performed,and MALDI-ToF profiles were generated.Clinical and food-associated strains as well as members of different varieties mated successfully and consequently they belong to a single biological species.Molecular differences did not match with any other parameter investigated.Based on these results the varieties of Rhizopus microsporus are reduced to synonyms.

Multilocus analysis of the Exophiala jeanselmei clade containing black yeasts involved in opportunistic disease in humans

To confirm species delimitations in the‘jeanselmeiclade’in the Chaetothyriales,four independent markers were analysed,and phylogenetic trees were reconstructed using different algorithms.Reproductive isolation within the complex and reproductive modes in the species involved were determined,in order to explore specific borderlines using Genealogical Concordance Phylogenetic Species Recognition(GCPSR).Sequences of the Internal Transcribed Spacer(ITS),partial Translation Elongation Factor 1-α(TEF1),β-Tubulin(BT2),and Actin(ACT1)genes were analysed for a set of 81 strains.Phylogenetic reconstruction was performed using neighbour-joining(NJ),maximum parsimony(MP),maximum likelihood(ML)and Bayesian analysis(BA)to evaluate the concordance of topologies obtained under different optimization criteria.Incongruence among lineages was detected by Partition Homogeneity Test(PHT).Most Exophiala species analysed in this study seemed to be preponderantly clonal.A group of species around Exophiala spinifera showed a tendency toward human pathogenicity,whereas species around E.bergeri were often associated with environments rich in hydrocarbons.Though the tree topologies were not completely identical when different algorithms were used,the four gene lineages were nearly congruent and the trees of the combined multilocus data set did not provide more phylogenetic information than those of separate data sets.ITS data are sufficient for identification of species in the‘jeanselmei-clade’.

Novel Phialophora species from leaf-cutting ants (tribe Attini)

Ants in the tribe Attini(Hymenoptera,Formicidae)maintain a 50 million-year-old lifestyle of co-evolution with symbiotic basidiomycetous fungi which they cultivate as essential source of nutrition.However,other microorganisms have been reported from ant habitats indicating a higher diversity of consistently associated species than established to date.Recently,black yeast-like fungi have been reported as a possible symbiont,like a competitor of the actinomycete bacteria that grow in the integument of the insects.During the mating season,gynes of Atta capiguara and A.laevigata were collected from nests located in Botucatu,SP,Brazil and sampled using flotation technique.Phylogenetic analysis based on ITS,partial 28S(LSU)andβ-tubulin sequences revealed the occurrence of two novel species of Phialophora among the melanized fungi isolated.

Proposed nomenclature for Pseudallescheria,Scedosporium and related genera

As a result of fundamental changes in the International Code of Nomenclature on the use of separate names for sexual and asexual stages of fungi,generic names of many groups should be reconsidered.Members of the ECMM/ISHAM working group on Pseudallescheria/Scedosporium infections herein advocate a novel nomenclature for genera and species in Pseudallescheria,Scedosporium and allied taxa.The generic names Parascedosporium,Lomentospora,Petriella,Petriellopsis,and Scedosporium are proposed for a lineage within Microascaceae with mostly Scedosporium anamorphs producing slimy,annellidic conidia.Considering that Scedosporium has priority over Pseudallescheria and that Scedosporium prolificans is phylogenetically distinct from the other Scedosporium species,some name changes are proposed.Pseudallescheria minutispora and Petriellidium desertorum are renamed as Scedosporium minutisporum and S.desertorum,respectively.Scedosporium prolificans is renamed as Lomentospora prolificans.

Dishwashers provide a selective extreme environment for human-opportunistic yeast-like fungi

Urban life has led to the creation of human-made environments that,from a microbiological perspective,provide extreme life conditions.Certain non-ubiquitous microorganisms such as thermophilic members of the black yeast genus Exophiala are enriched within these habitats for which no counterpart is known in nature.Dishwashers consistently accumulate a number of specific black,white and red yeasts on the rubber seals of doors and in stagnant water at the interior.Several of these yeasts are primarily known as agents of human opportunistic infections.In this review,the literature data are supported by a screening study involving 937 households in 15 cities in Turkey.Fungi were detected in 230 samples(24.5%).Using rDNA sequencing,the prevalent species were identified as Exophiala dermatitidis(n=116),Candida parapsilosis(n=44),E.phaeomuriformis(n=35),Magnusiomyces capitatus(n=22),Rhodotorula mucilaginosa(n=15),and C.lusitaniae(n=14).The possible role of dishwashers in transmitting disease is discussed.

Chaetomium-like fungi causing opportunistic infections in humans:a possible role for extremotolerance

Members of the family Chaetomiaceae are ubiquitous ascosporulating fungi commonly,which reside in soil enriched with manure or cellulosic materials.Their role as human pathogens is largely ignored.However,the ability of some species to grow at high temperature enables them to play an important role as opportunistic pathogens.The family contains several genera and species that have never been reported to cause human infection.Hereby,three new species are described;two belong to the genus Subramaniula and one represents a Chaetomium species.Subramaniula asteroides was isolated from various sources including eye and skin infections as well as from the natural environment,and S.obscura was isolated from a toe infection.Chaetomium anamorphosum was isolated from a kidney transplant patient suffering from fungal peritonitis.All species described were previously misidentified as Papulaspora spp.due to the formation of cellular clumps or bulbil-like structures,which are characteristic of Papulaspora.The isolates failed to form sexual fruit bodies and ascospores remained absent,which is an unusual feature for the generally ascosporulating genera Chaetomium and Subramaniula;minute conidia from phialides were sometimes observed.