Fulminating fungal sinusitis caused by Valsa sordida, a plant pathogen, in a patient immunocompromised by acute myeloid leukemia

Comparative Assessment of Habitat Suitability and Niche Overlap of Three Cytospora Species in China

The plant pathogenic fungus Cytospora is notoriously known for causing woody plant canker diseases, resulting in substantial economic losses to biological forests and fruit trees worldwide. Despite their strong negative ecological impact, the existing and prospective distribution patterns of these plant pathogens in China, according to climate change, have received little attention. In this study, we chose three widely dispersed and seriously damaging species, namely, Cytospora chrysosperma, Cytospora mali, and Cytospora nivea, which are the most common species that damage the Juglans regia, Malus domestica, Eucalyptus, Pyrus sinkiangensis, Populus spp., and Salix spp. in China. We utilized ecological niche modeling to forecast their regional distribution in China under four climate change scenarios (present, SSP 126, SSP 370, and SSP 585). The results show that temperature-related climate factors limit the current distribution ranges of the three species. Currently, the three studied species are highly suitable for northeast, northwest, north, and southwest China. Under future climate scenarios, the distribution ranges of the three species are projected to increase, and the centers of the adequate distribution areas of the three species are expected to shift to high-latitude regions. The three species coexist in China, primarily in the northwest and north regions. The ecological niches of C. chrysosperma and C. nivea are more similar. The distribution range of C. mali can reach the warmer and wetter eastern region, whereas C. chrysosperma and C. nivea are primarily found in drought-prone areas with little rainfall. Our findings can help farmers and planners develop methods to avoid the spread of Cytospora spp. and calculate the costs of applying pesticides to reduce contamination and boost yields.

Bioactive Secondary Metabolites from Fungi of the Genus Cytospora Ehrenb. (Ascomycota)

Cytospora is a genus of fungi belonging to the Cytosporaceae family (Sordariomycetes, Ascomycota) considered as a prolific source of specialized metabolites due to their ability to produce diverse secondary metabolites with a broad range of biological activities. Since the first chemical investigation of this genus in the 1980s, further studies have led to the isolation and structural elucidation of several bioactive compounds including cytosporones, nonanolides, macrocyclic dilactones, and terpenoids. This review summarizes, for the first time, the chemical diversity of bioactive secondary metabolites from the genus Cytospora and highlights its potential as an alternative source of secondary metabolites for pharmacological studies. Moreover, this review will serve as a basis for future investigations of compounds of this genus.

Comparative genomics of five Valsa species gives insights on their pathogenicity evolution

Valsa is a genus of ascomycetes within the Valsaceae family. This family includes many wood destructive pathogens such as the well known Valsa mali and Valsa pyri which cause canker diseases in fruit trees and threaten the global fruit production. Lack of genomic information of this family is impeding our understandings about their evolution and genetic basis of their pathogenicity divergence. Here, we report genome assemblies of Valsa malicola, Valsa persoonii, and Valsa sordida which represent close relatives of Valsa mali and Valsa pyri with different host preferences. Comparative genomics analysis revealed that segmental rearrangements, inversions, and translocations frequently occurred among Valsa spp. genomes. Gene families that exhibited gene copy expansions tended to be associated with secondary metabolism, transmembrane transport, and pyrophosphatase activities. Orthologous genes in regions lost synteny exhibited significantly higher rate of synonymous substitution (KS) than those in regions retained synteny. Moreover, among these genes, membrane transporter families associated with antidrug (MFS, DHA) activities and nutrient transportation (SP and APCs) activities were significantly over-represented. Lineage specific synonymous substitution (KS) and nonsynonymous substitution (KA) analysis based on the phylogeny constructed from 11 fungal species identified a set of genes with selection signatures in Valsa clade and these genes were significantly enriched in functions associated with fatty acid beta-oxidation, DNA helicase activity, and ATPase activity. Furthermore, unique genes that possessed or retained by each of the five Valsa species are more likely part of the secondary metabolic (SM) gene clusters. SM gene clusters conserved across five Valsa species showed various degrees of diversification in both identity and completeness. All 11 syntenically conserved SM clusters showed differential expression during the infection of apple branch with Valsa mali suggesting involvements of secondary metabolism in the pathogenicity of Valsa species.

Multigene phylogeny, morphology, and pathogenicity trials reveal novel Cytospora species involved in perennial canker disease of apple trees in Iran

In recent years, canker and die-back diseases have become a growing threat for the productivity and longevity of apple orchards in Iran. In this study, 131 Cytospora isolates were recovered from symptomatic tissues of apple trees in apple orchards of Iran. Multigene phylogenetic inference based on combined sequence data of ITS, act, rpb2, and tef1-α loci, supplemented with morphological characteristics and pathogenicity assay revealed four novel Cytospora species which were described as C. avicennae, C. azerbaijanica, C. ershadii, and C. iranica, and four known species, namely C. chrysosperma, C. parasitica, C. paratranslucens, and C. sorbicola. Also, C. sorbicola is newly reported on apple trees worldwide. Koch's postulates were fulfilled to confirm that all eight species in this study were pathogenic on apple trees in Iran, among which C. sorbicola was the most intensive species. The results of this study further highlight rich diversity among Cytospora species occurring on apple trees, revealing several novel Cytospora species on this host. The host range, geographical distribution, and economic significance of novel species on apple industry remains to be studied.

Opportunistic phaeohyphomycoses in wild saffron cod Eleginus gracilis from waterways of Norton Sound and Toksook Bay, Alaska, USA

These case reports describe locally invasive black pigmented mycotic infections of the skin and gills of saffron cod Eleginus gracilis associated with 8 different opportunistic ascomycete fungi: Alternaria sp., Cladosporium herbarum, Chaetomium globosum, Cadophora luteo-olivacea, Penicillium sp., Phoma herbarum, Pseudophacidium ledi and Valsa sordida. These fungi were isolated on conventional media, identified according to morphological structures and confirmed by genetic sequencing. Several of these fungi are primary plant pathogens as well as opportunistic human pathogens in immunocompromised individuals. Several have also been described as causing opportunistic infections of fish. This case material represents the first report of C. luteo-olivacea, C. globosum, P. ledi and V. sordida as likely opportunistic fish pathogens in Alaskan watersheds of Norton Sound and south in Toksook Bay and possibly elsewhere.

Cytospora (Diaporthales) in China

Members of the genus Cytospora are often reported as endophytes, saprobes or phytopathogens, primarily causing canker diseases of woody host plants. They occur on a wide range of hosts and have a worldwide distribution. Although several species have in the past been reported from China, the vast majority are not known from culture or DNA phylogeny. The primary aim of the present study was thus to clarify the taxonomy and phylogeny of a large collection of Cytospora species associated with diverse hosts in China. Cytospora spp. were collected in northeast, northwest, north and southwest China, indicating that the cold and dry environments favour these fungi. In this paper, we provide an assessment of 52 Cytospora spp. in China, focussing on 40 species represented by 88 isolates from 28 host genera. Based on a combination of morphology and a six-locus phylogeny (ITS, LSU, act1, rpb2, tef1-α and tub2), 13 new species and one new combination are introduced. The majority of the species investigated here appear to be host-specific, although further collections and pathogenicity studies will be required to confirm this conclusion.

Indoor airborne fungal pollution in newborn units in Turkey

Pathogenic and/or opportunistic fungal species are major causes of nosocomial infections, especially in controlled environments where immunocompromised patients are hospitalized. Indoor fungal contamination in hospital air is associated with a wide range of adverse health effects. Regular determination of fungal spore counts in controlled hospital environments may help reduce the risk of fungal infections. Because infants have inchoate immune systems, they are given immunocompromised patient status. The aim of the present study was to evaluate culturable airborne fungi in the air of hospital newborn units in the Thrace, Marmara, Aegean, and Central Anatolia regions of Turkey. A total of 108 air samples were collected seasonally from newborn units in July 2012, October 2012, January 2013, and April 2013 by using an air sampler and dichloran 18% glycerol agar (DG18) as isolation media. We obtained 2593 fungal colonies comprising 370 fungal isolates representing 109 species of 28 genera, which were identified through multi-loci gene sequencing. Penicillium, Aspergillus, Cladosporium, Talaromyces, and Alternaria were the most abundant genera identified (35.14, 25.40, 17.57, 2.70, and 6.22% of the total, respectively).

Effects of Temperature, Humidity, and Wound Age on Valsa mali Infection of Apple Shoot Pruning Wounds

Valsa canker, caused by Valsa mali, is a destructive disease of apple in China. The pathogen infects apple branches, mainly through pruning wounds, and causes branch and tree death. To determine the conditions required for V. mali infection through pruning wounds and growth within the xylem, pruning wounds on 1- to 4-year-old apple branches were inoculated with conidia in vitro under artificially controlled conditions and in vivo in the orchard. The effects of temperature, wetness duration, and wound age on conidial infection through pruning wounds as well as hyphal growth in the xylem were examined. The results showed that, after invading through pruning wounds, V. mali hyphae grew along xylem vessels, tracheids, and rays, expanding longitudinally and laterally. The hyphae could enter adjacent xylem vessels and tracheids through micropores to form a dense hyphal network. Wetness duration did not exhibit an essential effect on conidial infection from pruning wounds. Conidia spread to pruning wounds with rainwater could infect the xylem without any other extra moisture. Temperature for V. mali conidia infection through pruning wounds and hyphal extension in the xylem ranged from 5 to 35°C, with the optimum at 20°C. Pruning wounds made in late March were susceptible to V. mali infection in March, April, and May; the susceptibility was markedly deceased by June, and the pathogen could barely infect through the pruning wounds in November. The infected pruning wounds began to show symptoms from the spring of the following year. More than half of the observed Valsa canker lesions emerged in the spring of the second year, and new canker twigs were also developed from the inoculations in the spring of the third year. March, April, and May are the critical periods for protecting pruning wounds against infection by V. mali in China, and coating pruning wounds with protective film immediately after pruning is an easy and effective measure to protect the pruning wounds.

Redefining the human oral mycobiome with improved practices in amplicon-based taxonomy: discovery of Malassezia as a prominent commensal

Fungi are a large, complex group, increasingly recognized as emerging threats. Their roles as modifiers of health mandate accurate portrayals of fungal communities in humans. As an entry point into the airways and gastrointestinal tract, fungi in the mouth are relevant to several biocompartments. We have revised current practices in sequence-based taxonomy assignments and employed the improvements to address the question of the fungal genera present in the healthy human mouth. The human oral mycobiome was surveyed using massively parallel, high throughput sequencing of internal transcribed spacer 1 (ITS1) amplicons from saliva following robust extraction methods. Taxonomy was assigned by comparison to a curated reference dataset, followed by filtering with an empirically determined BLAST E-value match statistic (10⁻⁴²). Nomenclature corrections further refined results by conjoining redundant names for a single fungal genus. Following these curation steps, about two-thirds of the initially identified genera were eliminated. In comparison with the one similar metagenomic study and several earlier culture-based ones, our findings change the current conception of the oral mycobiome, especially with the discovery of the high prevalence and abundance of the genus Malassezia. Previously identified as an important pathogen of the skin, and recently reported as the predominant fungal genus at the nostril and backs of the head and ear, this is the first account of Malassezia in the human mouth. Findings from this study were in good agreement with others on the existence of many consensus members of the core mycobiome, and on unique patterns for individual subjects. This research offered a cautionary note about unconditional acceptance of lengthy lists of community members produced by automated assignments, provided a roadmap for enhancing the likely biological relevance of sequence-based fungal surveys, and built the foundation for understanding the role of fungi in health and disease of the oral cavity.

Epidemiology and Medical Mycology of Fungal Rhinosinusitis

Fungal rhinosinusitis (FRS) refers to a spectrum of disease ranging from benign colonization of the nose and sinuses by pathogenic fungi to acute invasive and fatal inflammation extending to the orbit and brain. FRS is classified into two categories: invasive and noninvasive. Invasive FRS may again be subcategorized into acute invasive (fulminant) FRS, granulomatous invasive FRS, and chronic invasive FRS; while noninvasive FRS is subcategorized into localized fungal colonization, sinus fungal ball and eosinophil related FRS (including allergic fungal rhinosinusitis, eosinophilic fungal rhinosinusitis). This classification is not without controversies, and intermediate and semi-invasive forms may also exist in particular patients. Acute invasive FRS is an increasingly common disease worldwide among the immunocompromised patients and caused most frequently by Rhizopus oryzae, and Aspergillus spp. Granulomatous invasive FRS has mostly been reported from Sudan, India, and Pakistan and is characterized by noncaseating granuloma formation, vascular proliferation, vasculitis, perivascular fibrosis, sparse hyphae in tissue, and isolation of A. flavus from sinus contents. Chronic invasive FRS is an emerging entity occurring commonly in diabetics and patients on corticosteroid therapy, and is characterized by dense accumulation of hyphae, occasional presence of vascular invasion, sparse inflammatory reaction, involvement of local structures, and isolation of A. fumigatus. While localized fungal colonization describes the most benign of all fungal sinusitis in the superficial nasal crusts, sinus fungal ball is a dense mycetoma like aggregate of fungal hyphae in diseased sinuses. Common in southern Europe, especially France, majority of them are sterile on culture while 30-50% may yield Aspergillus spp. The definitions and pathogenesis of the group of syndromes in eosinophil related FRS (AFRS, EFRS) are contentious and a matter of intense research among otolaryngologists, pathologists, immunologists and microbiologists. While dematiaceous fungi are the foremost initiators of these syndromes in the west, Aspergillus flavus is the predominant pathogen in India and the Middle-East.

Orbital and cranial nerve presentations and sequelae are hallmarks of invasive fungal sinusitis caused by Mucor in contrast to Aspergillus

BACKGROUND

Acute fulminant invasive fungal sinusitis (IFS) is a rapidly progressing, destructive process almost exclusively affecting immunocompromised patients. Outcome differences have been found in patients with Mucor and Aspergillus. We performed this study to compare the presenting symptoms and long-term morbidity with IFS caused by Mucor versus Aspergillus species.

METHODS

Retrospective chart review was performed of 48 patients with 49 cases of acute fulminant IFS over a 19-year period. Presenting symptoms and long-term morbidity related to the orbits and cranial nerves were evaluated.

RESULTS

Mucor was found in 22 cases and Aspergillus was found in 27 cases. Orbital (proptosis, periorbital edema, and ophthalmoplegia) and cranial nerve symptoms were seen at presentation more often in Mucor (6 [27%] and 9 [41%]) than in Aspergillus patients (3 [11%] and 7 [26%]; p=0.079). Long-term orbital and cranial nerve sequelae occurred in 16 (72%) Mucor cases and 10 (37%) Aspergillus cases (p=0.0210). The IFS-related mortality was 32% (7) in the Mucor group and 11% (3) in the Aspergillus group (p=0.089).

CONCLUSION

Patients with acute fulminant IFS present with similar sinus symptoms; however, there is a trend toward a greater prevalence of orbital and neurological symptoms in patients with Mucor versus Aspergillus. Long-term orbital and neurological morbidity is more prevalent in patients with Mucor compared with Aspergillus. These data suggest that the presence of orbital and neurological symptoms at presentation warrants more aggressive surgical intervention because of the likelihood of Mucor.