Production and characterization of an enzyme extract with cellulase activity produced by an indigenous strain of Fusarium verticillioides ITV03 using sweet sorghum bagasse.

OBJECTIVES: To evaluate a strain of Fusarium verticillioides ITV03 isolated from wood residues in the Veracruz region of Mexico. Endoglucanase and ß-glucosidase production by submerged fermentation was optimized using a Box-Behnken design, where the independent variables were urea, ammonium sulfate and yeast extract. RESULTS: After optimization, an endoglucanase activity of 0.27 U/mL was achieved; subsequently, three carbon sources were evaluated (carboxymethyl cellulose, sweet sorghum bagasse cellulose and delignified sweet sorghum bagasse (DSSB). The results showed that DSSB yielded the greatest endoglucanase (0.28 U/mL) and ß-glucosidase (0.12 U/mL) activities. Both enzymatic activities were characterized for the effect of pH, temperature and thermostability. The optimal parameters of ß-glucosidase and endoglucanase activity were pH 5 and 4 respectively, the optimum temperature 60 °C. These enzymes were stable at 50 °C for 150.68 h and 8.54 h, with an activation energy (Ea(day)) of 265.55 kJ/mol and 44.40 kJ/mol respectively, for ß-glucosidase and endoglucanase. CONCLUSION: The present work shows that a native strain like F. verticillioides ITV03 using DSSB supplemented with nitrogen has a great potential as a producer of cellulase for lignocellulosic residue hydrolysis.

Risk of Fungal Infection to Dental Patients.

Fungi can cause various diseases, and some pathogenic fungi have been detected in the water of dental equipment. This environment offers suitable conditions for fungal biofilms to emerge, which can facilitate mycological contamination. This study verified whether the water employed in the dental units of two dental clinics at the University of Franca was contaminated with fungi. This study also evaluated the ability of the detected fungi to form biofilms. The high-revving engine contained the largest average amount of fungi, 14.93 ± 18.18 CFU/mL. The main fungal species verified in this equipment belonged to the genera Aspergillus spp., Fusarium spp., Candida spp., and Rhodotorula spp. Among the isolated filamentous fungi, only one fungus of the genus Fusarium spp. did not form biofilms. As for yeasts, all the Candida spp. isolates grew as biofilm, but none of the Rhodotorula spp. isolates demonstrated this ability. Given that professionals and patients are often exposed to water and aerosols generated by the dental procedure, the several fungal species detected herein represent a potential risk especially to immunocompromised patients undergoing dental treatment. Therefore, frequent microbiological monitoring of the water employed in dental equipment is crucial to reduce the presence of contaminants.

[Biodegradation of agricultural plant residues by Fusarium oxysporum strains].

The cellulolytic and endoglucanase activity of Fusarium oxysporum strains isolated from soil and plants in the media with plant waste as carbon source has been studied. It was established that the majority of studied strains were able to hydrolyze the filter paper, husk of sunflower seeds, wheat straw and corn stalks. Cellulolytic activity depended on the strain of microscopic fungi, type of substrate and duration of cultivation. The maximum cellulase activity 1 U/ml and the concentration of reducing sugars -0.875 mg/ml were found in soil strain F. oxysporum 420 in the medium with corn stalks. Endoglucanase activity of plant pathogenic strains was higher than that of soil ones.

Surface-Imprinted Polysiloxane with Recognition Ability Based on an ITO Layer for Rapid Detection of Fusarium oxysporum f. sp. cubense by the Naked Eye.

Direct observation by the naked eye of fluorescence-stained microbes adsorbed on surface imprinted polymers (SIPs) is highly challenging and limited by speed, accuracy and the semiquantitative nature of the method. In this study, we tested for the presence of spores of Fusarium oxysporum f. sp. cubense race 4 (Foc4), which cause severe banana Fusarium wilt disease and reduces the area of banana plants. This kind of spore can become dormant in soil, which means that the detection of secreted molecules (molecular imprinting) in soil may be inaccurate; detection methods such as polymerase chain reaction (PCR) and Raman spectroscopy are more accurate but time-consuming and inconvenient. Therefore, a semiquantitative and rapid SIP detection method for Foc4 was proposed. Based on the ITO conductive layer, a reusable and naked-eye-detectable Foc4-PDMS SIP film was prepared with a site density of approximately 9000 mm-2. Adsorption experiments showed that when the Foc4 spore concentration was between 104 to 107 CFU/mL, the number of Foc4 spores adsorbed and the fluorescence intensity were strongly correlated with the concentration and could be fully distinguished by the naked eye after fluorescence staining. Adsorption tests on other microbes showed that the SIP film completely recognized only the Foc series. All the results were highly consistent with the naked-eye observations after fluorescence staining, and the results of the Foc4-infected soil experiment were also close to the ideal situation. Taken together, these results showed that Foc4-PDMS SIPs have the ability to rapidly and semiquantitatively detect the concentration of Foc in soil, which can provide good support for banana cultivation. This method also has potential applications in the detection of other fungal diseases.

An inordinate fondness for Fusarium: phylogenetic diversity of fusaria cultivated by ambrosia beetles in the genus Euwallacea on avocado and other plant hosts.

Ambrosia beetle fungiculture represents one of the most ecologically and evolutionarily successful symbioses, as evidenced by the 11 independent origins and 3500 species of ambrosia beetles. Here we document the evolution of a clade within Fusarium associated with ambrosia beetles in the genus Euwallacea (Coleoptera: Scolytinae). Ambrosia Fusarium Clade (AFC) symbionts are unusual in that some are plant pathogens that cause significant damage in naïve natural and cultivated ecosystems, and currently threaten avocado production in the United States, Israel and Australia. Most AFC fusaria produce unusual clavate macroconidia that serve as a putative food source for their insect mutualists. AFC symbionts were abundant in the heads of four Euwallacea spp., which suggests that they are transported within and from the natal gallery in mandibular mycangia. In a four-locus phylogenetic analysis, the AFC was resolved in a strongly supported monophyletic group within the previously described Clade 3 of the Fusarium solani species complex (FSSC). Divergence-time estimates place the origin of the AFC in the early Miocene ∼21.2 Mya, which coincides with the hypothesized adaptive radiation of the Xyleborini. Two strongly supported clades within the AFC (Clades A and B) were identified that include nine species lineages associated with ambrosia beetles, eight with Euwallacea spp. and one reportedly with Xyleborus ferrugineus, and two lineages with no known beetle association. More derived lineages within the AFC showed fixation of the clavate (club-shaped) macroconidial trait, while basal lineages showed a mix of clavate and more typical fusiform macroconidia. AFC lineages consisted mostly of genetically identical individuals associated with specific insect hosts in defined geographic locations, with at least three interspecific hybridization events inferred based on discordant placement in individual gene genealogies and detection of recombinant loci. Overall, these data are consistent with a strong evolutionary trend toward obligate symbiosis coupled with secondary contact and interspecific hybridization.

Fusarium euwallaceae sp. nov.--a symbiotic fungus of Euwallacea sp., an invasive ambrosia beetle in Israel and California.

The invasive Asian ambrosia beetle Euwallacea sp. (Coleoptera, Scolytinae, Xyleborini) and a novel Fusarium sp. that it farms in its galleries as a source of nutrition causes serious damage to more than 20 species of live trees and pose a serious threat to avocado production (Persea americana) in Israel and California. Adult female beetles are equipped with mandibular mycangia in which its fungal symbiont is transported within and from the natal galleries. Damage caused to the xylem is associated with disease symptoms that include sugar or gum exudates, dieback, wilt and ultimately host tree mortality. In 2012 the beetle was recorded on more than 200 and 20 different urban landscape species in southern California and Israel respectively. Euwallacea sp. and its symbiont are closely related to the tea shot-hole borer (E. fornicatus) and its obligate symbiont, F. ambrosium occurring in Sri Lanka and India. To distinguish these beetles, hereafter the unnamed xyleborine in Israel and California will be referred to as Euwallacea sp. IS/CA. Both fusaria exhibit distinctive ecologies and produce clavate macroconidia, which we think might represent an adaption to the species-specific beetle partner. Both fusaria comprise a genealogically exclusive lineage within Clade 3 of the Fusarium solani species complex (FSSC) that can be differentiated with arbitrarily primed PCR. Currently these fusaria can be distinguished only phenotypically by the abundant production of blue to brownish macroconidia in the symbiont of Euwallacea sp. IS/CA and their rarity or absence in F. ambrosium. We speculate that obligate symbiosis of Euwallacea and Fusarium, might have driven ecological speciation in these mutualists. Thus, the purpose of this paper is to describe and illustrate the novel, economically destructive avocado pathogen as Fusarium euwallaceae sp. nov. S. Freeman et al.

[Pathogenic properties of fungi Fusarium genus isolated from patients with atopic dermatitis].

AIM: Study of adhesive activity and growth speed of fungi Fusarium genus isolated from the surface of cutaneous covering in patients with atopic dermatitis (AD). MATERIALS AND METHODS: Clinical and museum F. oxysporum, F. solani strains were used in the study. Seeding was carried out into agarized Czapek and Sabouraud medium. The cultures were studied for9 days at 30 +/- 2 degrees C, adhesive properties of fungi were determined by using model based on nitrocellulose film (S.A. Lisovskaya et al., 2006). RESULTS: The studies carried out showed statistically significant differences in adhesive properties and intergrowth intensity of various Fusarium spp. Adhesion level of F. solani microconidia was almost 2.5 times higher compared with F. oxysporum. Formation of the first germ tube by F. solani microconidia was noted during the first 10 hours whereas by F. oxysporum--only at day 2. CONCLUSION: The data obtained confirm species differences of Fusarium spp. pathogenic properties that emphasize the importance of species identification of fungi.

[Utilization of carbon sources by Fusarium poae (Peck) Wollenw. Strains from different trophic groups].

It was shown that saprophytic (soil), endophytic and plant pathogenic strains of F. poae under cultivation conditions in the media containing carbon sources from mono- to polysaccharides had different abilities to use them and to accumulate biomass. Maltose, xylose, fructose, pectin were the most favorable carbon sources for the studied strains; less assimilated lactose, arabinose, and especially microcrystalline cellulose were less assimilated. It was found that endophytes and plant pathogens accumulated biomass equally, while soil strains had low ability for that.

Surface-modified sulfur nanoparticles: an effective antifungal agent against Aspergillus niger and Fusarium oxysporum.

Surface-modified sulfur nanoparticles (SNPs) of two different sizes were prepared via a modified liquid-phase precipitation method, using sodium polysulfide and ammonium polysulfide as starting material and polyethylene glycol-400 (PEG-400) as the surface stabilizing agent. Surface topology, size distribution, surface modification of SNPs with PEG-400, quantitative analysis for the presence of sulfur in nanoformulations, and thermal stability of SNPs were determined by atomic force microscopy (AFM), dynamic light scattering (DLS) plus high-resolution transmission electron microscopy (HR-TEM), fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray (EDX) spectroscopy, and thermogravimetric analysis (TGA), respectively. A simultaneous study with micron-sized sulfur (S(0)) and SNPs was carried out to evaluate their fungicidal efficacy against Aspergillus niger and Fusarium oxysporum in terms of radial growth, sporulation, ultrastructural modifications, and phospholipid content of the fungal strains using a modified poisoned food technique, spore-germination slide bioassay, environmental scanning electron microscopy (ESEM), and spectrometry. SNPs expressed promising inhibitory effect on fungal growth and sporulation and also significantly reduced phospholipid content.

Evaluation of the microbial flora found in woodwind and brass instruments and their potential to transmit diseases.

Previous studies of dental devices (toothbrushes, dentures, and protective athletic mouthguards) have demonstrated microbial contamination of these devices and possible transmission of infectious diseases to the users. Since woodwind and brass instruments come into intimate contact with the musician's oral cavity and often are passed from student to student without sanitization, the question arises as to whether these instruments are contaminated and can transmit microbial diseases. The purpose of this study was to determine if woodwind and brass instruments and/or their cases harbor opportunistic, pathogenic, or allergenic microorganisms that can be transmitted to the musician. The internal components of woodwind and brass instruments harbored opportunistic, pathogenic, and/or allergenic microorganisms. The highest concentrations of microorganisms were found consistently at the mouthpiece end, but there was evidence of contamination throughout the instruments and their cases. The close proximity of contaminated mouthpieces to the oral cavity could facilitate local and systemic dissemination of the resident opportunistic, pathogenic, and/or allergenic microorganisms. General dentists should determine whether patients play a brass or woodwind instrument and be aware of the possible impact of this activity on the oral cavity and the entire body.

Surgical outcomes in cases of contact lens-related Fusarium keratitis.

OBJECTIVES: To examine seven cases of contact lens-related Fusarium keratitis that resulted in therapeutic penetrating keratoplasty, to investigate which factors were associated with favorable versus poor graft outcome in this population. METHODS: Seven patients who underwent corneal transplant after contact lens-related, culture-proven Fusarium keratitis were identified through a retrospective chart review. The cases occurred between September 2005 and January 2006 at the University of Medicine and Dentistry of New Jersey and Wills Eye Hospital. All seven patients had used Bausch and Lomb's ReNu with MoistureLoc. The outcomes studied were graft status, infection recurrence, and 6-month postoperative visual acuity. RESULTS: The rejection rate was 57.1% and the recurrence rate was 28.6% in this study. No eyes were lost to fungal endophthalmitis. In this population, larger ulcer size and a greater total number of medical agents used before and after penetrating keratoplasty were significantly associated with poor outcomes, namely graft rejection and poor visual acuity. In addition, it was noted that the patients who suffered recurrence of infection had both a larger median graft size and a longer median duration of postoperative antifungal use although these results did not reach statistical significance. CONCLUSIONS: Larger ulcer size, larger graft size, a greater number of medical agents used, and a longer duration of postoperative antifungal therapy may be useful parameters in predicting surgical outcomes in patients with fungal keratitis. Further research is needed to validate our results and to elucidate the mechanisms behind graft rejection in the setting of fungal keratitis.

The multivariate statistical selection of fungal strains isolated from Neoteredo reynei, with the high hydrolytic potential to deconstruct cellulose.

The aim of this study was to select isolated filamentous fungi, naturally occurring in the digestive tract of Neoteredo reynei, with high potential to hydrolyze cellulolytic biomass. The selection of the fungi strains, which produce cellulases, was performed by adding carboxymethylcellulose (CMC), microcrystalline cellulose (MCC) or glucose in the media containing peptone and yeast-extract. In this case, the glucose was used as a reference standard for the growth of the mycelia. The abilities of the fungal strains, to hydrolyze cellulose, on the solid media (MCC or CMC), were evaluated. Two methods were used: the congo-red and the speed of mycelial growth. The measurements of the diameters were performed at 24 h intervals, and the speed of the mycelial growth was calculated after 72 h of cultivation. The molecular and morphological identification of the fungi were applied to the isolated strains. Statistical analysis, including ANOVA and Tukey test, and multivariate analysis were applied as tools to select the strains. Twelve strains were isolated and the results of the identification were 2 strains of Hypocrea lutea, 2 strains of Trichoderma reesei, 2 strains of Aspergillus niger; 2 genera of Aspergillus sp., 2 genera of Trichoderma sp., 1 genus of Fusarium sp. and 1 genus of Gliocadium sp. The discrimination analysis methods such as HCA (Hierarchical Cluster Analysis) and PCA (Principal Component Analysis) indicated three strains with the highest potential to hydrolyze cellulose. In this study, the selection strategy was successful, resulting in the classification of strains from the genera Trichoderma and Hypocrea. This is the first time that this kind of studying was applied to select the potential of the cellulolytic fungal strains, isolated from N. reynei, using the methods of the growth of the mycelial diameter and the statistical discrimination.

Maxillary fungus balls due to Fusarium proliferatum.

Fungus ball is the most common form of non-invasive fungal rhinosinusitis. Aspergillusfumigatus (between 44.8% and 75%) and Aspergillusflavus (14%) are the two most common species recovered. However, recent advances in mycological laboratory methods have enhanced the detection and identification of fungi within fungus balls. Fusarium species, sometimes recovered from other forms of fungal rhinosinusitis such as allergic fungal rhinosinusitis or acute invasive fungal rhinosinusitis, are poorly associated with sinonasal fungus ball. Here, we describe two further cases of a fungus ball due to Fusariumproliferatum and provide the first description of this fungal pathogen with a fungus ball of odontogenic origin. These case reports demonstrate that uncommon fungal species such as Fusarium spp. might be underestimated as agents of sinusal cavity fungus ball. Enhanced mycological detection and diagnostic techniques might give rise, in the near future, to the emergence of new or rare fungal species associated with this clinical entity.

Screening of a fungus capable of powerful and selective delignification on wheat straw.

AIMS: To screen and characterize a novel fungus with powerful and selective delignification capability on wheat straw. METHODS AND RESULTS: A fungus capable of efficient delignification under solid-state fermentation (SSF) conditions on wheat straw was screened. After 5 days of incubation, 13.07% of the lignin was removed by fungal degradation, and 7.62% of the holocellulose was lost. Furthermore, 46.53% of the alkali lignin was removed after 2 days of liquid fermentation. The fungus was identified as Fusarium concolor based on its morphology and an analysis of its 18S rDNA gene sequence. The molecular weight distribution of lignin was evaluated by gel permeation chromatography. Enzyme assay indicated that the fungus produced laccase, cellobiose dehydrogenase, xylanase and cellulase during the incubation period. Intracellular lignin peroxidase, manganese peroxidase and laccase were produced during liquid fermentation. CONCLUSIONS: We have successfully screened a fungus, F. concolor, which can efficiently degrade the lignin of wheat straw, with slight damage to the cellulose, after 5 days of SSF. SIGNIFICANCE AND IMPACT OF THE STUDY: The newly isolated strain could be used in pretreatment of lignocellulose materials prior to biopulping, bioconversion into fuel and substrates for the chemical industry.

An ascomycota coculture in batch bioreactor is better than polycultures for cellulase production.

Efficient hydrolysis of holocellulose depends on a proper balance between cellulase (endoglucanase, exoglucanase, ß-glucosidase) and xylanase activities. The present study aimed to induce the production of cellulases and xylanases using liquid cultures (one, two, three, and four fungal strains on the same bioreactor) of wild strains of Trichoderma harzianum, Aspergillus niger, and Fusarium oxysporum. The strains were identified by amplification and analysis of the ITS rDNA region and the obtained sequences were deposited in Genbank. Enzymes (endoglucanase, exoglucansae, ß-glucosidase, and xylanase activities) and the profile of extracellular protein isoforms (SDS-PAGE) produced by different fungal combinations (N = 14) were analyzed by Pearson's correlation matrix and principal component analysis (PCA). According to our results, induction of endoglucanase (19.02%) and ß-glucosidase (6.35%) were obtained after 4 days when A. niger and F. oxysporum were cocultured. The combination of A. niger-T. harzianum produced higher endoglucanase in a shorter time than monocultures. On the contrary, when more than two strains were cultured in the same reactor, the relationships of competition were established, trending to diminish the amount of enzymes and the extracellular protein isoforms produced. The xylanase production was sensible to stress produced by mixed cultures, decreasing their activity. This is important when the aim is to produce cellulase-free xylanase. In addition, exoglucanase activity did not change in the combinations tested.

Fungal thigmotropism in onychomycosis and in a clear hydrogel pad model.

BACKGROUND: Thigmotropism is a biological characteristic corresponding to the directional growth of cells following topographical guidance cues. This behavior has been shown experimentally with fungal hyphae of both dermatophytes and nondermatophyte molds, as well as with the mycelial phase of the dimorphic yeast Candida albicans. OBJECTIVE AND METHODS: We presently document this phenomenon using histomycology in onychomycoses of various fungal origins. RESULTS: This mechanism is involved in the invasive phase of the pathogen or opportunistic fungi, and it probably governs various clinical aspects of onychomycoses. We incidentally disclosed fungal invasions of hydrogel pads. CONCLUSION: Thigmotropism can in part explain the diversity of orientations and shapes of fungi invading nail plates. The same phenomenon was disclosed inside hydrogel pads. As this material is transparent and easy to cut for microscopic examination, fungal thigmotropism is conveniently explored by this way.

Growth and survival of Fusarium solani-F. oxysporum complex on stressed multipurpose contact lens care solution films on plastic surfaces in situ and in vitro.

PURPOSE: To analyze factors implicating the association of ReNu with MoistureLoc (ReNu ML) multipurpose contact lens solution (MPS) with the increased incidence of Fusarium keratitis. METHODS: Used contact lens cases with and without contact lenses and MPS containers were collected from patients with confirmed or possible Fusarium keratitis. Direct microscopy including transparent adhesive tape preparations and swab cultures were used to determine fungal colonization. Survival and growth of selected isolates of Fusarium spp. in drying MPS on plastic surfaces were determined by microscopy and recoverable colony counts on enriched agar. RESULTS: Discrete regions of fungal colonization, including occasional microcycle conidiation and chlamydospore formation, were observed on the surfaces of contact lens cases and, less often, on solution containers that had been used by patients with Fusarium keratitis associated with the use of ReNu ML. Isolates provisionally grouped with the F. solani-F. oxysporum complex were inhibited by fresh MPS in original solution containers and contact lens cases, but survived in stressed (drying) films of MPS, particularly ReNu ML. These in vitro test results were similar to the direct in situ observations of the materials from patients. CONCLUSIONS: Selective, rapid growth and survival of cells of the F. solani-F. oxysporum complex on plastic surfaces, particularly of contact lens cases with stressed ReNu ML films, may explain, in part, the recent Fusarium keratitis outbreak.

A case of fusariosis in an immunocompromised patient successfully treated with liposomal amphotericin B.

Although aspergillosis remains the most common mould infection in patients with haematologic malignancies, disseminated Fusarium infection is an emerging problem with a poor prognosis in this patient population. The treatment options are limited due to relative resistance of the fungus to standard antifungals. We present a patient with acute lymphoblastic leukaemia successfully treated with AmBisome for a disseminated Fusarium solani infection that did not respond to first line treatment with voriconazole. Despite the fact that he received additional myelosuppressive chemotherapy and underwent two stem cell transplantations from HLA mismatched donors the Fusarium infection did not recur during the subsequent phases of neutropenia. The clinical presentation, diagnosis, prognosis and therapeutic options of fusariosis in immunocompromised patients are briefly discussed.

Two isolates of Fusarium proliferatum from different habitats and global locations have similar abilities to degrade lignin.

Two isolates of Fusarium proliferatum from different global locations and habitats mineralized several natural and synthetic lignins. MUCL 31970 was isolated from a forest soil whereas the second strain, NRRL 31071, was a wheat endophyte causing disease in stressed seedlings. Onset and the fastest rate of lignin mineralization occurred during logarithmic and early stationary-phase of culture. Reduction of glucose in the medium shortened log-growth phase and advanced the onset of mineralization for both isolates. Mineralization correlated with the detection of extracellular laccase and aryl alcohol oxidase activities. The carbon-nitrogen ratio in the medium influenced laccase isozyme production and secretion by both strains. These studies suggest that both F. proliferatum strains degrade lignin via comparable routes, despite their different habitats and saprophytic or endophytic strategies.

[Keratomycosis due to Fusarium oxysporum treated with the combination povidone iodine eye drops and oral fluconazole]. / Kératomycose à Fusarium oxysporum traitée par l'association de la povidone iodée en collyre et du fluconazole per os.

In developing countries where systemic antifungal are often unavailable, treatment of filamentous fungi infection as Fusarium is sometimes very difficult to treat. We report the case of a keratomycosis due to Fusarium oxysporum treated by povidone iodine eye drops and oral fluconazole. The diagnosis of abscess in the cornea was retained after ophthalmological examination for a 28-year-old man with no previous ophthalmological disease, addressed to the Ophthalmological clinic at the University Hospital Le Dantec in Dakar for a left painful red eye with decreased visual acuity lasting for 15 days. The patient did not receive any foreign body into the eye. Samples by corneal scraping were made for microbiological analysis and the patient was hospitalized and treated with a reinforced eye drops based treatment (ceftriaxone+gentamicin). The mycological diagnosis revealed the presence of a mold: F. oxysporum, which motivated the replacement of the initial treatment by eye drops containing iodized povidone solution at 1% because of the amphotericin B unavailability. Due to the threat of visual loss, oral fluconazole was added to the local treatment with eye drops povidone iodine. The outcome was favorable with a healing abscess and visual acuity amounted to 1/200th. Furthermore, we noted sequels such as pannus and pillowcase. The vulgarization of efficient topical antifungal in developing countries would be necessary to optimize fungal infection treatment.