Acremonium strictum: Report of a Rare Emerging Agent of Cutaneous Hyalohyphomycosis with Review of Literatures

We present a case of cutaneous hyalohyphomycosis due to Acremonium strictum in an immunocompetent individual along with an overview of fungal infections caused by A. strictum. The diagnosis was confirmed by the presence of hyphae in microscopic examination of cutaneous biopsy and discharge, positive culture for A. strictum and sequencing of the isolate at reference centre. The infection resolved with itraconazole and terbinafine. Cutaneous or subcutaneous infections of A. strictum have rarely been reported. Fungemia or disseminated infection often with fatal outcome in immunocompromised patients was the most common presentation of A. strictum infection found in the literatures. The studies also reveal worldwide variation in the treatment regime and outcome of the treatment.     

Prosthetic valvular endocarditis due to the fungus Paecilomyces

The third reported case of prosthetic valvular endocarditis caused by the fungus Paecilomyces is presented. The clinical course of the patient is discussed. The distinctive morphology of the fungus is described, together with the histologic and cytologic features found in the excised prosthetic valve and in the tissues at autopsy. Prosthetic valvular endocarditis presents a serious antibiotic and surgical problem in therapy. Despite antifungal antibiotics and valve replacement this patient died as a result of metastatic cerebral microabscesses and subarachnoid hemorrhage.     

Is the root-colonizing endophyte <Emphasis Type="Italic">Acremonium strictum</Emphasis> an ericoid mycorrhizal fungus?

In previous investigations, we found that Acremonium strictum (strain DSM 100709) developed intracellular structures with similarity to mycelia of ericoid mycorrhizal fungi in the rhizodermal cells of flax plants and in hair roots of Rhododendron plantlets. A. strictum had also been isolated from roots of ericaceous salal plants and was described as an unusual ericoid mycorrhizal fungus (ERMF). As its mycorrhizal traits were doubted, we revised the hypothesis of a mycorrhizal nature of A. strictum. A successful synthesis of mycorrhiza in hair roots of inoculated ericaceous plants was a first step of evidence, followed by fluorescence microscopy with FUN^®1 cell stain to observe the vitality of the host cells at the early infection stage. In inoculation trials with in vitro-raised mycorrhiza-free Rhododendron plants in axenic liquid culture and in greenhouse substrate culture, A. strictum was never observed in living hair root cells. As compared to the ERMF Oidiodendron maius and Rhizoscyphus ericae that invaded metabolically active host cells and established a symbiotic unit, A. strictum was only found in cells that were dead or in the process of dying and in the apoplast. In conclusion, A. strictum does not behave like a common ERMF—if it is one at all. A comparison of A. strictum isolates from ericaceous and non-ericaceous hosts could reveal further identity details to generalize or specify our findings on the symbiotic nature of A. strictum. At least, the staining method enables to discern between true mycorrhizal and other root endophytes—a tool for further studies.     

Interactions between Psilocybe fasciata and its companion fungus Acremonium strictum

Interactions between Psilocybe fasciata and its companion fungus Acremonium strictum were analysed. The conidia of A. strictum were observed on stipe, flesh and gill of P. fasciata, which suggested that A. strictum is the fungicolous fungi or mycophilic fungi of P. fasciata. The microscopic observations of the interacting hyphae of P. fasciata and A. strictum in dual culture and the negligible activities of chitinase and β-1,3-glucanase in inducing or non-inducing media of the pure and mixed cultures of the two fungi indicated that A. strictum is not the mycoparasite of P. fasciata. In addition, the co-existence, no pigmentation and dew formation in dual culture of both fungi were observed, which implied that the interference competition between the two fungi is weak. The activities of cellobiase, filter paper enzyme, endoglucanase and xylanase of pure and mixed cultures of P. fasciata and A. strictum were the same or similar, which may allow the co-existence of the two fungi. As a consequence of coevolution, the relationship between P. fasciata and A. strictum is commensalism: A. strictum showed no clear benefit to P. fasciata; however, P. fasciata may shelter A. strictum by its psychoactive tryptamines and may be helpful to conidium dispersal of A. strictum. The relationship between P. fasciata and A. strictum is different from that of A. strictum and other fungi.     

Acremomannolipin A,the potential calcium signal modulator with a characteristic glycolipid structure from the filamentous fungus Acremonium strictum

By the newly developed assay method, the glycolipid Acremomannolipin A (1) was isolated from a filamentous fungus Acremonium strictum as a potential calcium signal modulator. The structure of 1 elucidated on the basis of intensive spectroscopic analyses as well as its degradation studies is quite unique: the d-mannopyranose is connected to d-mannitol through a β-glycoside linkage; all the hydroxyls in the mannose are highly masked as peresters with aliphatic acids, and this moiety is made hydrophobic, whereas the mannitol part exhibits a highly hydrophilic property. The compound (1) showed the characteristic bioactivity property, enabling calcineurin deletion cells to grow in the presence of Cl^?, which would be caused by calcium signal modulating. The activity was so potent as to exert the effect at a concentration of 200 nM.     

Effects of temperature and glucose concentration on the growth and respiration of fungal species isolated from a highly productive coastal upwelling ecosystem

Respiration and growth rates were measured in five species of fungi (Penicillium decumbens, P. chrysogenum, Acremonium strictum, Fusarium fujikuroi and F. sporotrichioides) isolated from the upwelling system off the coast of central-south Chile to determine the effects of glucose availability and temperature. Growth was monitored by epifluorescence microscopy, ATP measurements, and optical density. Oxygen consumption was recorded via a respirometer with Optode sensors. Although species-specific responses were found, overall both respiration and growth increased with temperature and glucose concentration. Growth of P. decumbens, F. sporotrichioides and F. fujikuroi was more favoured by temperature when glucose remained stable. P. chrysogenum had a particular growth pattern, which seemed to be more linked to glucose availability than directly to temperature. Growth of F. sporotrichioides and A. strictum responded to the synergistic interaction between temperature and glucose. Values of Q₁₀ for fungal respiration ranged from 2.2 to 6.7, indicating a strong temperature-dependence of respiration rates, especially in A. strictum and F. sporotrichioides.     

Polytrichum Strictum as a Solution to Frost Heaving in Disturbed Ecosystems: A Case Study with Milled Peatlands

Substrate instability is a common problem in many disturbed ecosystems. In the case of milled harvested peatlands, the pioneer moss Polytrichum strictum is commonly found; it is well adapted to tolerate the harsh microclimatic conditions and peat instability of these sites. A field experiment was used to determine the effectiveness of P. strictum against frost heaving, a major type of disturbance on bare peat. Wooden dowels and fir trees (Abies balsamea) placed in a P. strictum carpet experienced almost no frost heaving, whereas heaving was severe on bare peat. Reintroduced P. strictum fragments thinly spread on bare peat reduced but did not eliminate frost heaving. Straw mulch (a protective cover often required in peatland restoration) effectively reduced heaving in the fall, but was less effective in the spring because it had partially decomposed. The P. strictum carpet, P. strictum fragments, and straw mulch reduced frost heaving by reducing the number of freeze–thaw cycles, by slowing the rate of ground thaw in the spring, and by reducing the unfrozen water content of the peat during the spring thaw. Different species of Polytrichum mosses should be considered for the restoration or regeneration of disturbed ecosystems where soil stability is problematic.     

The central axis prosthetic cardiac valve: an in vitro study of pressure drop assessment under steady-state flow conditions

In this work, a new mechanical prosthetic heart valve, the central axis valve, is presented. This new prosthesis has been tested in vitro, and compared with four other common prosthetic cardiac valves (Starr-Edwards 6120, Bjork-Shiley monostrut, Medtronic-Hall, and St Jude Medical valves). All valves studied have the same orifice diameter of 22 mm. The prostheses were installed inside a transparent mitral test chamber, which enables pressure drop measurement to be made under steady-state flow conditions using a blood analogue fluid. Pressure drop loss is one important factor affecting the overall performance of a prosthetic heart valve. Steady-state flow tests are essential to predict certain flow characteristics and pressure gradient loss before more complicated, expensive, and difficult-to-interpret pulsatile flow tests are conducted. All experiments were performed in vitro and at steady volumetric flow rates of 10 to 30 l/min. The Starr-Edwards SE 6120 showed the highest values for pressure drop. The St Jude Medical valve offers the minimum resistance to flow. The central axis valve comes second to the Starr-Edwards valve for this type of measurement. The new valve is promising. A complete valve evaluation programme, covering initial conceptional design through to clinical use, is in progress. Materials for the fabrication of the new valve are also under consideration.     

Osmophilic fungi of desert soils in Saudi Arabia

100 osmophilic species in addition to two varieties which belong to 38 genera were isolated from desert soils of Saudi Arabia. The most prevalent genera were Asperngillus, Altemaria, Penicillium, Cephalosporium, Acremonium and Botryotrichum which occurred in 55–97.5% of the samples contributing 1.8–45.2% of total fungi. From the preceding genera A. amstelodami, A. fumigatus, A. terreus, A. niger, A. flavipes, A. repens, A. alternata, P. notatum, P. chrysogenum, P. citrinum, C.? racifi, A. strictum and B. atrogriseum were the most common. Five genera were recovered in moderate frequency namely, Ulocladium, Fusarium, Drechslera, Microascus, Syncephalastrum and Cladosporium which emerged in 25–42% of the samples comprising 0.7–2.8% of total fungi. The results obtained in the present investigation reveal that the fungus flora of Saudi Arabian soils is of osmophilic nature.     

Contribution to the biology of germination of four species ofChenopodium album agg. under different condition

The study investigated various factors stimulating germination of seeds of four species ofChenopodium album agg.—C. album L. s. str.,C. ficifolium Sm.,C. strictum Roth,C. suecicum J. Murr. These factors were: storage in wet and cold, alternating temperature, nitrates mainly in combination with light and, to a lesser degree, the duration of chilling. Germination was inhibited by darkness, which was most marked with seeds ofC. strictum. The effect of alternating temperature was better on the germination ofC. ficifolium andC. suecicum than on that ofC. album andC. strictum. We also discussed several differences in specific reactions of the individual species to the factors under consideration.     

Meanderella rijsii,a new opportunist in the fungal order Pleosporales

Subcutaneous phaeohyphomycosis is an implantation disease caused by melanized fungi and affect both immunocompetent as well as immunocompromised individuals. Diagnosis and treatment require proper isolation and accurate identification of the causative pathogen. We isolated a novel fungus from a case of subcutaneous phaeohyphomycosis in an immunocompetent patient. The 56-year-old patient suffered from a slowly progressive swelling on the metatarsophalangeal join of the left food. The isolated fungus lacked sporulation and sequences of the ribosomal operon did not match with any known species. In a multi-locus phylogenetic analysis involving five markers, the fungus formed a unique lineage in the order Pleosporales, family Trematosphaeriaceae. A new genus, Meanderella and a new species, Meanderella rijsii are here proposed to accommodate the clinical isolate. Whole genome analysis of M. rijsii revealed a number of genes that can be linked to pathogenicity and virulence. Further studies are however needed to understand the role of each gene in the pathogenic process and to determine the origin of pathogenicity in the family of Trematosphaeriaceae.     

Genome sequence of Acremonium strictum AAJ6 strain isolated from the Cerrado biome in Brazil and CAZymes expression in thermotolerant industrial yeast for ethanol production

Increased demand for biofuels promotes the search for new biomass-degrading fungi. Acremonium strictum is an environmentally widespread filamentous fungi found on plant debris; that secretes lignocellulose-degrading enzymes. A recently isolated A. strictum strain, AAJ6; native to the Brazilian Cerrado biome was evaluated for its capacity to degrade lignocellulosic substrates. In this study, whole-genome sequencing of AAJ6 was performed and 775 CAZy domains were identified which correlated to those of A. strictum strain DS1bioAY4a and other lignocellulolytic fungi; suggesting AAJ6 is a high CAZyme producer. We expressed the glycoside hydrolase families GH74 and GH3 from plasmid or genome-integrated to evaluate the ethanol production from cellulosic substrates in Brazilian industrial Saccharomyces cerevisiae strains (PE-2 and SA-1) evolved for thermotolerance (AMY12 and AMY35). Those expressing the genome-integrated enzymes showed the highest β-glucosidase activity and growth in medium with cellobiose at 40°C. The strain AGY005 (integrated cassettes) showed 19, 23 and 46% higher ethanol production in SHF, pSSF (partial hydrolysis SSF) and SSF processes, respectively, using Avicel, and ∼50% more ethanol using pre-treated sugarcane bagasse, compared to the strain with a plasmid-based expression. These results indicate the improved performance of thermotolerant industrial strains with genome-integrated CAZymes in the SSF process for 2G ethanol.     

Evolutionary relationships in the genus <Emphasis Type="Italic">Secale</Emphasis> revealed by DArTseq DNA polymorphism

Till this day, there is not much known about the phylogeny of the Secale genus; therefore, in our research, we tried to shed some lights on the issue of rye (Secale genus) taxonomy. The genetic diversity and phylogenetic relationships were evaluated using 13,842 DArTseq? polymorphic markers. The model-based clustering (STRUCTURE software) separated our 84 samples into three main clusters: perennial cluster, annual cluster, and S. sylvestre cluster. The same result was obtained using Neighbour Joining tree and self-organizing maps. Secale sylvestre, S. strictum, and S. cereale are the three main species of the Secale genus. Three samples of rye are in basal positions in phylogenetic trees. These accessions share ancient morphological characters and are probably the ancestors of different lineages within Secale. Annual Secale taxa, with the exception of S. sylvestre, create one mutual taxon. We have found out that the semi-perennial taxa of S. cereale var. multicaule and S. strictum subsp. ciliatoglume are genetically closest to the annual species of S. cereale. Phylogenetic signals for semi-perennial and annual taxa are also present in S. strictum subsp. africanum. SNP-based analysis revealed that evolution of annual S. cereale has already begun in S. strictum subsp. africanum. The results showed that S. vavilovii cannot be considered as a separate species but a subspecies of S. cereale Secale cereale subsp. dighoricum is a hybrid. It is still not clear whether we can consider S. strictum subsp. strictum and S. strictum subsp. kuprijanovii as two separate species.     

<Emphasis Type="Italic">Acremonium strictum</Emphasis> Fungaemia in a Paediatric Immunocompromised Patient: Diagnosis and Treatment Difficulties

During the past two decades, an increasing number of unusual moulds has been reported as responsible for septicaemia and systemic or disseminated infections in immunocompromised patients. Investigation of fever in a 10-year-old boy with acute myeloblastic leukaemia, including blood cultures on selective media, allowed the diagnosis of a fungaemia due to the slow-growing fungus Acremonium strictum. The patient recovered with liposomal amphotericin B (AmB) and voriconazole, followed by voriconazole alone due to AmB resistance. Facing a neutropenic patient with fever, clinicians usually suspect bacterial or viral aetiologies. This case, however, illustrates the need for mycological analysis of blood samples in febrile neutropenic patients and for antifungal susceptibility testing.     

春兰菌根真菌CL-3菌株的鉴定及共生体系的构建

采用分离自野生春兰(Cymbidium goeringii)根部的真菌CL-3菌株, 进行了春兰内生菌根真菌的人工接种、再分离及其共生培养研究。通过对CL-3菌株形态学观察和ITS序列同源性分析, 发现该菌株ITS序列与Acremonium strictum的亲缘关系最为接近, 序列同源性为100%。用CL-3菌株接种春兰组培苗, 接种后2个月可从组培苗中再分离获得该菌株, 且CL-3菌株处理苗的鲜重增长率达80.5%, 经方差分析, 与对照相比有显著差异。通过石蜡切片和染色, 在已接种的组培苗的根部组织中可观察到CL-3菌株存在。表明CL-3菌株能与组培幼苗成功建立共生培养体系。     

Influence of an endophytic fungus on host plant selection by a polyphagous moth via volatile spectrum changes

Recently the role of micro-organisms as mediators of plant-herbivore interactions has been increasingly acknowledged in ecological research. We investigated the interaction between an unspecialized root fungal endophyte (Acremonium strictum) and the polyphagous moth Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), in greenhouse and laboratory bioassays. Specifically we examined in tomato (Lycopersicon esculentum Mill.) the systemic effects of the endophytic fungus on the host selection behaviour of female moths for oviposition and the volatile profiles of host plants to understand the mechanisms acting in this multi-trophic model system. Both laboratory and field strains of H. armigera moths oviposited more on leaves of A. strictum inoculated plants as compared to endophyte-free plants, both in free flight cages and in tethered moth laboratory experiments; the moth’s preferences were significant between 10 and 18 days after inoculation. The analysis of volatile profiles showed strong quantitative differences between treatments. Endophyte inoculated plants emitted diverse terpenes and sesquiterpenes at significantly lower amounts as compared to endophyte free-plants, except for α-terpinene, which did not differ between the treatments, and trans-β-caryophyllene, which was emitted in significantly higher amounts on inoculated plants. β-Thujene and α-phellandrene accounted for 73.3 and 12.0% of total amounts of volatiles emitted from endophyte-free and inoculated plants, respectively. Our findings demonstrate that A. strictum is able to systemically influence the host selection of H. armigera moths for oviposition; conceivably mediated by the induced changes in volatile emissions (and probably additional biochemical parameters of the host plants, which have not been analysed so far). We argue for a more detailed assessment of micro-organisms invisibly colonizing plants, when studying plant-herbivore or multitrophic interactions.     

Fungal Endocarditis Observed Over an 8-Year Period and a Review of the Literature

Background

Fungal endocarditis (FE) is a “modern” disease that is considered an emerging cause of infective endocarditis (IE). The most frequently identified fungal pathogens are Candida spp., which are responsible for up to two-thirds of all cases; the remaining cases are due to Aspergillus spp., Histoplasma capsulatum or, more rarely, other yeasts and moulds.

Objectives

To describe the prevalence, clinical characteristics and outcome of FE diagnosed in a single tertiary centre and review the literature concerning FE.

Design and setting

An 8-year retrospective review of the case records of patients attending a single Italian University Centre and diagnosed as having definite or probable IE as defined by the modified Duke criteria.

Results

Six patients were identified from 229 episodes of IE: five cases involved a prosthetic valve, and one a native valve of an intravenous drug user. Five cases were caused by Candida spp. (two by C. albicans, one each by C. lusitaniae, C. dubliniensis and C. glabrata) and one by Aspergillus flavus. Three patients were treated by means of surgery plus antifungal therapy; two received antifungal therapy alone. Three patients survived, but only the patient with Aspergillus endocarditis was followed up for a long time.

Conclusions

FE is difficult to diagnose but generally associated with healthcare infections. The optimal treatment is poorly characterised, and international collaborative studies are urgently needed to evaluate newer antifungal agents.     

Biological control of root-knot nematode,Meloidogyne incognita infesting tomato

Talc based formulations of two antagonistic fungi, Acremonium strictum W. Gams and Aspergillus terreus Thom were tested separately and together for their ability to suppress the development of root-knot disease of tomato caused by the root-knot nematode, Meloidogyne incognita Kofoid & White in two consecutive trials (2007–08). Tomato seedlings were each inoculated with M. incognita at 2 infective second stage juveniles /g of soil. M. incognita caused up to 48% reduction in plant growth parameters compared to un-inoculated control. Control efficacy achieved by combined soil application of both fungi, in terms of galls/root system and soil population/50 ml of soil, was 66 and 69% respectively at 60 days of inoculation compared to control. Soil application by individual fungus did not achieve as much effectiveness as the biocontrol agents applied together. The combined treatment was found to have antagonistic effect on M. incognita development and increased plant vigor. Incorporation of fine powder of chickpea pod waste with talc powder was beneficial in providing additional nutrients to both plant and biocontrol agents and increased the activity of the nematophagous fungi in soil. A. strictum and A. terreus were successfully established in the rhizosphere of tomato plants up to the termination of the experiment.     

Fusion of a Xylan-Binding Module to Gluco-Oligosaccharide Oxidase Increases Activity and Promotes Stable Immobilization

The xylan-binding module Clostridium thermocellum CBM22A was successfully fused to a gluco-oligosaccharide oxidase, GOOX-VN, from Sarocladium strictum via a short TP linker, allowing the fused protein to effectively bind different xylans. The presence of the CtCBM22A at the N-terminal of GOOX-VN increased catalytic activity on mono- and oligo-saccharides by 2-3 fold while not affecting binding affinity to these substrates. Notably, both GOOX-VN and its CBM fusion also showed oxidation of xylo-oligosaccharides with degrees of polymerization greater than six. Whereas fusion to CtCBM22A did not alter the thermostability of GOOX-VN or reduce substrate inhibition, CtCBM22A_GOOX-VN could be immobilized to insoluble oat spelt xylan while retaining wild-type activity. QCM-D analysis showed that the fused enzyme remained bound during oxidation. These features could be harnessed to generate hemicellulose-based biosensors that detect and quantify the presence of different oligosaccharides.     

Comparison of Aortic Annulus Diameter Measurement between Multi-Detector Computed Tomography and Echocardiography: A Meta-Analysis

Background and Purpose

Accurate measurement of aortic annulus diameter is crucial for choosing suitable prosthetic size for transcatheter aortic valve implantation (TAVI). Several imaging methods are available for the measurement, but significant variability between different modalities has been observed. The purpose of this study was to systematically compare the measurements of aortic annulus diameter between multi-detector computed tomography (MDCT), transthoracic echocardiography (TTE), and transesophegeal echocardiography (TEE).

Methods

PubMed and EMBASE databases between January 2000 and January 2012 were searched. We extracted data from eligible studies evaluating the aortic annulus diameter by MDCT and echocardiography (TTE, TEE, or both). We performed a random-effects meta-analysis to calculate the weighted mean differences of aortic annulus diameter measurement between MDCT, TTE, and TEE.

Results

A total of 10 eligible studies involving 581 subjects with aortic valve stenosis were included. Aortic annulus diameter measured on coronal view by MDCT (25.3±0.52 mm) was respectively larger than that measured on sagittal view by MDCT (22.7±0.37 mm), TTE (22.6±0.28 mm), and TEE (23.1±0.32 mm). The weighted mean difference of aortic annulus diameter between coronal view by MDCT and TTE these two methods was 2.97 mm, followed by the weighted mean difference of 2.53 mm between coronal view and sagittal view by MDCT, and the mean difference of 1.74 mm between coronal view on MDCT and TEE (P<0.0001 for all). The weighted mean difference of aortic annulus diameter measurement between TEE and TTE was significant but somewhat small (0.45 mm, P = 0.007).

Conclusion

Aortic annulus diameter measured on coronal view by MDCT was robustly and significantly larger than that obtained on sagittal view by MDCT, TTE, or TEE. Such variability of aortic annulus diameter measurement by different imaging modalities cannot be ignored when developing optimal strategies for selection of prosthetic valve size in TAVI.