Steccherinum tenuissimum and S. xanthum spp. nov. (Polyporales, Basidiomycota): New species from China.

Two new wood-inhabiting fungal species, Steccherinum tenuissimum and S. xanthum spp. nov. are described based on a combination of morphological features and molecular evidence. Steccherinum tenuissimum is characterized by an annual growth habit, resupinate basidiomata with an odontioid hymenial surface, a dimitic hyphal system with clamped generative hyphae, strongly encrusted cystidia and basidiospores measuring 3-5 × 2-3.5 µm. Steccherinum xanthum is characterized by odontioid basidiomata and a monomitic hyphal system with generative hyphae bearing clamp connections and covering by crystals, colourless, thin-walled, smooth, IKI-, CB-and has basidiospores measuring 2.7-5.5 × 1.8-4.0 µm. Sequences of the ITS and nLSU nrRNA gene regions of the studied samples were generated, and phylogenetic analyses were performed with maximum likelihood, maximum parsimony and Bayesian inference methods. The phylogenetic analyses based on molecular data of ITS + nLSU sequences showed that two new Steccherinum species felled into the residual polyporoid clade. Further investigation was obtained for more representative taxa in Steccherinum based on ITS + nLSU sequences, which demonstrated that S. tenuissimum and S. xanthum were sister to S. robustius with high support (100% BP, 100% BS and 1.00 BPP).

Phylogeny and taxonomy of Ceriporia and other related taxa and description of three new species.

Species of Ceriporia (Irpicaceae, Basidiomycota) are saprotrophs or endophytes in forest ecosystems. To evaluate the taxonomy and generic relationships of Ceriporia and other related taxa, we used morphology and multigene phylogenetic analyses based on sequence data from nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS) region, nuc 28S rDNA (28S), and RNA polymerase II largest subunit (rpb1). Our results show that Ceriporia sensu lato is polyphyletic and distributed across multiple clades in the Irpicaceae, Phanerochaetaceae, and Meruliaceae. Some species previously considered in Ceriporia are now recovered in Meruliopsis, resulting in four new combinations: M. albomellea, M. crassitunicata, M. nanlingensis, and M. pseudocystidiata. Two new species of Meruliopsis are described: M. leptocystidiata from northeast China and South Korea and M. parvispora from Taiwan. Ceriporia arbuscula is described as a new species from Taiwan. Ceriporia mellita and Meruliopsis nanlingensis are newly recorded from Japan and Taiwan, and M. taxicola is recorded from Taiwan for the first time.

Low molecular weight chitosan is an effective antifungal agent against Botryosphaeria sp. and preservative agent for pear (Pyrus) fruits.

Antifungal activity and preservative effect of a low molecular weight chitosan (LMWC) sample, derived from chitosan by enzymatic hydrolysis, were investigated in vitro and in vivo. A pathogenic fungal strain was isolated from decayed pear (Pyrus bretschneideri cv. "Huangguan") fruit and identified as Botryosphaeria sp. W-01. LMWC was shown to strongly inhibit W-01 growth based on studies of minimum inhibitory concentration (MIC) and effects on mycelial biomass and radial growth of the fungus. LMWC treatment of W-01 cells reduced ergosterol synthesis and mitochondrial membrane potential (ΔY), early events of apoptosis. Transmission electron microscopy and confocal laser scanning microscopy studies revealed that LMWC penetrated inside W-01 hyphae, thereby inducing ultrastructural damage. LMWC coating had a significant preservative effect on wounded and nonwounded pear fruits, by inhibiting postharvest decay and browning processes. LMWC activated several defense-related enzymes (polyphenol oxidase, peroxidase, chitinase), maintained nutritional value, and slowed down weight loss. Our findings indicate the strong potential of LMWC as a natural preservative agent for fruits and vegetables.

New Fungus-Insect Symbiosis: Culturing, Molecular, and Histological Methods Determine Saprophytic Polyporales Mutualists of Ambrosiodmus Ambrosia Beetles.

Ambrosia symbiosis is an obligate, farming-like mutualism between wood-boring beetles and fungi. It evolved at least 11 times and includes many notorious invasive pests. All ambrosia beetles studied to date cultivate ascomycotan fungi: early colonizers of recently killed trees with poor wood digestion. Beetles in the widespread genus Ambrosiodmus, however, colonize decayed wood. We characterized the mycosymbionts of three Ambrosiodmus species using quantitative culturing, high-throughput metabarcoding, and histology. We determined the fungi to be within the Polyporales, closely related to Flavodon flavus. Culture-independent sequencing of Ambrosiodmus minor mycangia revealed a single operational taxonomic unit identical to the sequences from the cultured Flavodon. Histological sectioning confirmed that Ambrosiodmus possessed preoral mycangia containing dimitic hyphae similar to cultured F. cf. flavus. The Ambrosiodmus-Flavodon symbiosis is unique in several aspects: it is the first reported association between an ambrosia beetle and a basidiomycotan fungus; the mycosymbiont grows as hyphae in the mycangia, not as budding pseudo-mycelium; and the mycosymbiont is a white-rot saprophyte rather than an early colonizer: a previously undocumented wood borer niche. Few fungi are capable of turning rotten wood into complete animal nutrition. Several thousand beetle-fungus symbioses remain unstudied and promise unknown and unexpected mycological diversity and enzymatic innovations.

Primary hepatic aspergillosis following induction chemotherapy for acute leukemia.

Invasive aspergillosis (IA) contributes significantly to the burden of infectious complications in heavily immunosuppressed patients with acute leukemia. The infection is typically acquired via inhalation into the respiratory tract, and the lungs are most commonly involved. However, disseminated disease may occur and reports of isolated extrapulmonary infection suggest the gastrointestinal tract is likely an additional portal of entry for this organism. We describe a case of primary hepatic aspergillosis in a patient with acute myelogenous leukemia. The patient did not respond to medical therapy with antifungals and ultimately required surgical exploration and drainage. IA should be considered in an immunosuppressed patient with hepatic abscesses and may require a combined surgical and medical approach to therapy.

Genotyping Candida albicans from Candida leukoplakia and non-Candida leukoplakia shows no enrichment of multilocus sequence typing clades but enrichment of ABC genotype C in Candida leukoplakia.

Oral leukoplakias are histopathologically-diagnosed as Candida leukoplakia or non-Candida leukoplakia by the presence or absence of hyphae in the superficial epithelium. Candida leukoplakia lesions have significantly increased malignant potential. Candida albicans is the most prevalent fungal species associated with oral leukoplakia and may contribute to malignant transformation of Candida leukoplakia. To date, no detailed population analysis of C. albicans isolates from oral leukoplakia patients has been undertaken. This study investigated whether specific C. albicans genotypes were associated with Candida leukoplakia and non-Candida leukoplakia in a cohort of Irish patients. Patients with histopathologically-defined Candida leukoplakia (n = 31) or non-Candida leukoplakia (n = 47) were screened for Candida species by culture of oral rinse and lesional swab samples. Selected C. albicans isolates from Candida leukoplakia patients (n = 25), non-Candida leukoplakia patients (n = 19) and oral carriage isolates from age and sex matched healthy subjects without leukoplakia (n = 34) were subjected to multilocus sequence typing (MLST) and ABC genotyping. MLST revealed that the clade distribution of C. albicans from both Candida leukoplakia and non-Candida leukoplakia lesions overlapped with the corresponding clade distributions of oral carriage isolates and global reference isolates from the MLST database indicating no enrichment of leukoplakia-associated clones. Oral leukoplakia isolates were significantly enriched with ABC genotype C (12/44, 27.3%), particularly Candida leukoplakia isolates (9/25, 36%), relative to oral carriage isolates (3/34, 8.8%). Genotype C oral leukoplakia isolates were distributed in MLST clades 1,3,4,5,8,9 and 15, whereas genotype C oral carriage isolates were distributed in MLST clades 4 and 11.