Cladosporium cladosporioides and Cladosporium pseudocladosporioides as potential new fungal antagonists of Puccinia horiana Henn., the causal agent of chrysanthemum white rust.

Puccinia horiana Hennings, the causal agent of chrysanthemum white rust, is a worldwide quarantine organism and one of the most important fungal pathogens of Chrysanthemum × morifolium cultivars, which are used for cut flowers and as potted plants in commercial production regions of the world. It was previously reported to be controlled by Lecanicillium lecanii, Cladosporium sphaerospermum, C. uredinicola and Aphanocladium album, due to their antagonistic and hyperparasitic effects. We report novel antagonist species on Puccinia horiana. Fungi isolated from rust pustules in a commercial greenhouse from Villa Guerrero, México, were identified as Cladosporium cladosporioides and Cladosporium pseudocladosporioides based upon molecular analysis and morphological characters. The antagonism of C. cladosporioides and C. pseudocladosporioides on chrysanthemum white rust was studied using light and electron microscopy in vitro at the host/parasite interface. Cladosporium cladosporioides and C. pseudocladosporioides grew towards the white rust teliospores and colonized the sporogenous cells, but no direct penetration of teliospores was observed; however, the structure and cytoplasm of teliospores were altered. The two Cladosporium spp. were able to grow on media containing laminarin, but not when chitin was used as the sole carbon source; these results suggest that they are able to produce glucanases. Results from the study indicate that both Cladosporium species had potential as biological control agents of chrysanthemum white rust.

Biotransformation of cholesterol and 16,17-alpha epoxypregnenolone by novel Cladosporium sp. strain IS547.

Nowadays, there are a few steroid drugs or intermediates that have been obtained via the transformation of microorganisms, and many strains of transformed steroids have not been found yet. Therefore, it is very significant to screen for the strains that have the abilities to transform steroids to produce valuable products. This study has focused on the screen and identification of strains, the structural identification of converted products, and the optimization of transformation conditions, as well as the establishment of transformation systems. A soil microbiota was screened for strain involved in the biotransformation of steroids. A new isolate IS547 is capable of converting a variety of steroids (such as cholesterol, ergosterol, hydrocortisone, progesterone, pregnenolone, and 16,17-alpha-epoxypregnenolone). Based on the 18S rDNA gene sequence comparison, the isolate IS547 has been demonstrated to be very closely related to Cladosporium sp. genus. Present paper is the first report regarding the microbial transformation by Cladosporium sp. to produce active intermediates, which include 7-hydroxy cholesterol, 20-droxyl-16α,17α-epoxypregna-4-dien-3-one, 7-ketocholesterol, and 7-droxyl-16α,17α-epoxypregna-4-dien-3,20-dione. Under the optimum conditions, the yields of product 3 and product 4 were 20.58 and 17.42%, respectively, higher than that prior to the optimization. The transformation rate increased significantly under the optimum fermentation conditions. This study describes an efficient, rapid, and inexpensive biotransformation system for the production of active pharmaceutical intermediates.

The lactic acid bacteria metabolite phenyllactic acid inhibits both radial growth and sporulation of filamentous fungi.

BACKGROUND: Food spoilage caused by molds is a severe problem. In food and feed, e.g. dairy products, sourdough bread and silage, lactic acid bacteria are used as starter cultures. Besides lactic and acetic acid, some strains produce other low molecular weight compounds with antifungal activities. One of these metabolites is phenyllactic acid (PLA), well known for its antifungal effect. The inhibitory effect of PLA has only partially been investigated, and the objective of this study was to elucidate in detail the antifungal properties of PLA. RESULTS: We investigated the outgrowth of individual conidia from Aspergillus niger, Cladosporium cladosporioides and Penicillium roqueforti, and observed the morphologies of resulting colonies on solid media using different acid concentrations. We found that PLA inhibits molds similar to weak acid preservatives. Furthermore, it has an additional activity: at sub-inhibitory concentrations, fungal colonies displayed slower radial growth and inhibited sporulation. The L isoform of PLA is a more potent inhibitor than the D form. Increased expression of phiA was observed during PLA treatment. This gene was initially identified as being induced by Streptomyces-produced macrolide antibiotics, and is shown to be a structural protein in developed cells. This suggests that PhiA may act as a general stress protectant in fungi. CONCLUSION: From a food protection perspective, the results of this study support the usage of lactic acid bacteria strains synthesizing PLA as starter cultures in food and feed. Such starter cultures could inhibit spore synthesis, which would be beneficial as many food borne fungi are spread by airborne spores.

Biofouling and biodeterioration in materials stored at the Historical Archive of the Museum of La Plata, Argentine and at the National Archive of the Republic of Cuba.

The aims of this paper were to study the biofouling and biodeterioration of photos and maps stored at Historical Archive of the Museum of La Plata (HAMP), Argentine, and two repositories of the National Archive of Cuba Republic (NARC) and to carry out the physiological characterization of the isolated fungi and bacteria. The role of the environmental microbiota in the biofouling formation was also studied. Microbial assemblages in the air were sampled by sedimentation technique while those on documents were sampled by swabbering. Biofilm formation and biofouling were monitored by scanning electron microscope (SEM). Large microbial assemblages were found at NARC archives with the prevalence of genera Aspergillus, Cladosporium and Penicillium, whereas at HAMP these values were lower, Penicillium was the only fungal genus detected. Most of the fungi degraded cellulose and produced pigments and acids, and all of the isolated bacteria had proteolytic and/or cellulolytic activity. In all cases, a higher concentration of viable bacteria than of fungi was isolated from documents. These results correlated with bacterial values detected in air at NARC repositories. However, this correlation cannot be observed at HAMP where Aspergillus, Penicillium and Talaromyces helicus (teleomorph of Penicillium) were isolated. It is the first time that the last genus is reported in documents.

ß-Galactofuranose-containing structures present in the cell wall of the saprophytic fungus Cladosporium (Hormoconis) resinae.

A peptidogalactomannan was isolated from mycelia of Cladosporium (Hormoconis) resinae and characterized using methylation-fragmentation analysis, partial acid hydrolysis and ¹H and ¹³C-NMR spectroscopy. The galactomannan component was a branched structure and consisted of a main chain containing (1→6)-linked α-d-Manp residues substituted at O-2 by side chains containing (1→2)-linked α-D-Manp residues. ß-D-Galf residues were present as side chains of 3-4 units that are (1→5)-interlinked. This structure is very similar to a pGM isolated from Aspergillus fumigatus and differs from that of Cladosporium werneckii (currently named Hortaea werneckii), with this pGM and other fungal galactomannans having single terminal (1→6)-linked ß-Galf residues. The importance of the carbohydrate moiety of Cladosporium resinae pGM in immunoassays was also demonstrated. On FACS examination, a decrease (60%) in rabbit serum anti- C. resinae binding to C. resinae conidia occurred when this serum had been previously incubated with pGMs from C. resinae and A. fumigatus or with mannoprotein from Candida parapsilosis, suggesting the presence of cross-reactive determinants in these fungi.

Ecthyma-like phaeohyphomycosis caused by Cladosporium cladosporioides.

A case of cutaneous phaeohyphomycosis caused by Cladosporium cladosporioides in a 50-year-old housewife is described. The clinical presentation was an ecthyma-like crusted lesion on the back of her left hand. Scanning electron microscopy of the culture showed the conidiophores and the limoniform or ellipsoidal conidia, with a slightly verrucous surface. The lesion was removed surgically, with no relapses after 6-month follow up.

Treatment of fungal bioaerosols by a high-temperature, short-time process in a continuous-flow system.

Airborne fungi, termed fungal bioaerosols, have received attention due to the association with public health problems and the effects on living organisms in nature. There are growing concerns that fungal bioaerosols are relevant to the occurrence of allergies, opportunistic diseases in hospitals, and outbreaks of plant diseases. The search for ways of preventing and curing the harmful effects of fungal bioaerosols has created a high demand for the study and development of an efficient method of controlling bioaerosols. However, almost all modern microbiological studies and theories have focused on microorganisms in liquid and solid phases. We investigated the thermal heating effects on fungal bioaerosols in a continuous-flow environment. Although the thermal heating process has long been a traditional method of controlling microorganisms, the effect of a continuous high-temperature, short-time (HTST) process on airborne microorganisms has not been quantitatively investigated in terms of various aerosol properties. Our experimental results show that the geometric mean diameter of the tested fungal bioaerosols decreased when they were exposed to increases in the surrounding temperature. The HTST process produced a significant decline in the (1-->3)-beta-d-glucan concentration of fungal bioaerosols. More than 99% of the Aspergillus versicolor and Cladosporium cladosporioides bioaerosols lost their culturability in about 0.2 s when the surrounding temperature exceeded 350 degrees C and 400 degrees C, respectively. The instantaneous exposure to high temperature significantly changed the surface morphology of the fungal bioaerosols.

Intracellular sequestration of manganese and phosphorus in a metal-resistant fungus Cladosporium cladosporioides from deep-sea sediment.

A heavy metal resistant fungus was isolated from the sediment of Pacific Ocean, and identified to be Cladosporium cladosporioides. It grew normally in a medium containing 60 mM Mn(2+) and could endure 1,200 mM as the highest concentration tested. Quantification analysis confirmed a high accumulation of Mn which was 58 mg/g in dried biomass. Under transmission electron microscope, many intracellular crystals were observed in the cytoplasm of the hypha cells grown in a Mn-rich medium, and varied from a few nanometers to 200 nm in length. Energy dispersive X-ray (EDX) analysis showed that the crystals were composed of manganese and phosphorus in atomic ratio of 1.6:1 (Mn/P). Further, factors which might influence the resistance of this fungus were investigated. As a result, its high resistance to Mn(2+) was found dependent on the presence of Mg(2+), and could be further enhanced by phosphate. However, the effect of phosphate was not observed without the presence of Mg(2+). In addition, the resistance was also influenced by pH of the medium, which was lost above pH 8. This is the first report on a fungus which showed a hyper resistance to manganese by forming a large quantity of intracellular Mn/P crystals.

Cladosporium fulvum Avr4 protects fungal cell walls against hydrolysis by plant chitinases accumulating during infection.

Resistance against the leaf mold fungus Cladosporium fulvum is mediated by the tomato Cf proteins which belong to the class of receptor-like proteins and indirectly recognize extracellular avirulence proteins (Avrs) of the fungus. Apart from triggering disease resistance, Avrs are believed to play a role in pathogenicity or virulence of C. fulvum. Here, we report on the avirulence protein Avr4, which is a chitin-binding lectin containing an invertebrate chitin-binding domain (CBM14). This domain is found in many eukaryotes, but has not yet been described in fungal or plant genomes. We found that interaction of Avr4 with chitin is specific, because it does not interact with other cell wall polysaccharides. Avr4 binds to chitin oligomers with a minimal length of three N-acetyl glucosamine residues. In vitro, Avr4 protects chitin against hydrolysis by plant chitinases. Avr4 also binds to chitin in cell walls of the fungi Trichoderma viride and Fusarium solani f. sp. phaseoli and protects these fungi against normally deleterious concentrations of plant chitinases. In situ fluorescence studies showed that Avr4 also binds to cell walls of C. fulvum during infection of tomato, where it most likely protects the fungus against tomato chitinases, suggesting that Avr4 is a counter-defensive virulence factor.

Morphological significance of cladosporium contaminants on materials and utensils in contact with food.

Cladosporium contaminants on materials and utensils that come into contact with food were morphologically investigated. The most common contaminants, C. cladosporioides and C. sphaerospermum, were detected on the samples. The morphological changes of the Cladosporium species were investigated by using stereoscopic, optical light, fluorescent, and scanning electron microscopes. Microscopically the Cladosporium contaminants were observed as aggregated dark brown spots, strongly pigmented, irregularly swollen, and in long chains. Using fluorescent microscopy, the Cladosporium mycelia were clearly stained with fluorescein diacetate as viable cells, but the old cells were mostly non-viable, as shown by staining with propidium iodide. The dynamics of the morphological changes showed that the penetrating mycelia were closely attached to the surface of the materials and utensils under investigation. These results provide information about the significance of Cladosporium contamination on materials and utensils in contact with food and may contribute to the control of fungal contamination.

Immunochemical comparison of the allergenic potency of spores and mycelium of Cladosporium cladosporioides extracts by a nitrocellulose electroblotting technique.

BACKGROUND: The lack of well standardized or characterized extracts that contain the relevant allergens of the appropriate fungus is resulting in a high heterogeneity of the commercial preparation. MATERIAL AND METHODS: Immunochemical detection of the allergens composition of spore and mycelium of C. cladosporioides was studied by electroblotting using sera from Cladosporium allergic patients and 125 I- anti- human IgE. A MW range of allergens between 16 to 88 KDa was identified. The most important with a MW of 16, 20,30, 39, 43, 50, 60 and 88 KDa. RESULTS: The allergenic composition of spore and mycelium looked very similar. However, partial or total inhibition of the serum with a conidial or mycelial extract demonstrated that the total concentration of allergens (particulary 20 and 60 KDa molecules) was higher in the conidium than in the mycelium. CONCLUSIONS: These results indicated that conidium and mycelium contained the same allergenic determinants but at different concentration in the two propagule. Results with 50 % inhibited sera demonstrated also that the total concentration of allergens was higher in the conidium than in the mycelium.

Immunochemical comparison of the allergenic potency of spores and mycelium of cladosporium cladosporioides extracts by a nitrocellulose electroblotting technique / Comparación inmunoquímica de la potencia alergénica de los extractos de esporas y mecilio del cladosporium cladosporioides por una técnica de eletroblotting en nitrocelulosa

Background: The lack of well standardized or characterized extracts that contain the relevant allergens of the appropriate fungus is resulting in a high heterogeneity of the commercial preparation. Material and methods: Immunochemical detection of the allergens composition of spore and mycelium of C. cladosporioides was studied by electroblotting using sera from Cladosporium allergic patients and 125 I- anti- human IgE. A MW range of allergens between 16 to 88 KDa was identified. The most important with a MW of 16, 20,30, 39, 43, 50, 60 and 88 KDa. Results: The allergenic composition of spore and mycelium looked very similar. However, partial or total inhibition of the serum with a conidial or mycelial extract demonstrated that the total concentration of allergens (particulary 20 and 60 KDa molecules) was higher in the conidium than in the mycelium. Conclusions: These results indicated that conidium and mycelium contained the same allergenic determinants but at different concentration in the two propagule. Results with 50 % inhibited sera demonstrated also that the total concentration of allergens was higher in the conidium than in the mycelium

Antecedentes: La falta de extractos estandarizados o caracterizados que contienen alergenos relevantes de componentes fúngicos, da como resultado una elevada heterogeneidad de los preparados comerciales. Material and methods. La detección inmunoquímica de la composición alergénica de las esporas y del micelio de C. Cladosporioides ha sido estudiada por el método del electroblotting usando sueros procedentes de pacientes alérgicos a Cladosporium y anti-IgE humano marcado con Yodo 125. El peso molecular de los alergenos identificados fue situado entre 16 y 88 Kda. Los más importantes con un peso molecular de 16, 20, 30, 39, 43, 50, 60 y 88 Kda. Resultados: La composición alergénica detectada en las espora y el micelio ha sido idéntica. Sin embargo, la inhibición parcial o total del suero con extractos de esporas o micelios ha demostrado que la dosis de alergenos (especialmente de 20 y 60 KDa) ha sido más alta en las esporas que en el micelio. Conclusiones: Estos resultados indican que las esporas y los micelios contienen los mismos determinantes alergénicos pero a diferente concentración en ambos extractos. Con un 50% de inhibición sérica, la concentración de alergenos fue más elevada para las esporas que para los milecelios

Comparison of the allergenic potency of spores and mycelium of Cladosporium.

The allergenic potency of spore and mycelium extracts of Cladosporium was estimated by RAST, RAST inhibition and PCA tests. Spores contained a concentration of allergens higher than mycelia. Results of PCA tests suggested that spores contained specific allergens. However, in a comparative study of extracts from different species of Cladosporium animal and human models gave different estimates of the allergenic potency of the different species. In spite of these variations it was shown that extracts from spores of Cladosporium contained the highest amount of Cladosporium allergens.

Biosorption of organochlorine pesticides using fungal biomass.

Cladosporium strain AJR(3)18501 was tested for its ability to sorb the organochlorine pesticide (OCP) p,p'-DDT from aqueous media. When p,p'-DDT was added to distilled water, ethanol or 1-propanol solutions in excess of its solubility, p,p'-DDT was sorbed onto the fungal biomass. Increasing the amount of p,p'-DDT in solution by changing the medium composition increased sorbent uptake: p,p'-DDT uptake by the fungal biomass was 2.5 times greater in 25% 1-propanol (17 mg of p,p'-DDT g(-1) dry weight fungal biomass) than in distilled water. When p,p'-DDT was dissolved in 25% 1-propanol (12 mg x l(-1)), rapid p,p'-DDT sorption occurred during the first 60 min of incubation. p,p'-DDT in solution was reduced to 2.5 mg x l(-1) with the remaining p,p'-DDT recovered from the fungal biomass. A number of environmental parameters were tested to determine their effect on p,p'-DDT biosorption. As arsenic (As) is prevalent at DDT-contaminated cattle dip sites, its effect on p,p'-DDT uptake was determined. The presence of As [As(III) or As(V) up to 50 mg x l(-1)] did not inhibit p,p'-DDT uptake and neither As species could be sorbed by the fungal biomass. Changing the pH of the medium from pH 3 to 10 had a small effect on p,p'-DDT sorption at low pH indicating that an ion exchange process is not the major mechanism for p,p'-DDT sorption. Other mechanisms such as Van der Waals forces, chemical binding, hydrogen bonding or ligand exchange may be involved in p,p'-DDT uptake by Cladosporium strain AJR(3)18501.

Cladospolide D, a new 12-membered macrolide antibiotic produced by Cladosporium sp. FT-0012.

A new antibiotic termed cladospolide D was isolated along with the known cladospolides A and B from the fermentation broth of Cladosporium sp. FT-0012 by solvent extraction, ODS column chromatography and preparative HPLC. The structure of cladospolide D was deduced to be (E)-2-dodecen-5-hydroxy-11-olide-4-one. Cladospolide D showed antifungal activity against Pyricularia oryzae and Mucor racemosus.

Case report. Cutaneous phaeohyphomycosis caused by Cladosporium oxysporum.

The case of a 66-year-old woman with Cushing syndrome and a 1-year history of papulo-nodular lesions on the right leg is reported. Biopsy revealed septate hyphae and yeast-like cells in granulomatous dermo-hypodermal lesions. Culture of biopsy fragments on Sabouraud glucose agar without cycloheximide produced colonies that were olive green on top and greenish black underneath. On the basis of microscope findings and scanning electron microscopy observation of fragments of colonies, a diagnosis of cutaneous phaeohyphomycosis due to Cladosporium oxysporum was made. The patient was initially treated with itraconazole, which led to clinical improvement, but mycological recovery was obtained after a course of ketoconazole, made necessary by the presence of pituitary adenoma. To our knowledge, this is the first reported case of subcutaneous phaeohyphomycosis due to Cl. oxysporum.

Cutaneous phaeohyphomycosis due to Cladophialophora bantiana.

We present a case of cutaneous infection due to Cladophialophora bantiana, an agent of phaeohyphomycosis. The patient developed a nodule with pustule formation on the dorsum of the left hand; no trauma was reported. The lesion was successfully treated with itraconazole and surgical excision. Histopathologically, there was a blastomycosis-like tissue reaction pattern. Pigmented organisms were readily identified in tissue sections, and the cultural characteristics were those of Cladophialophora bantiana. This organism, known primarily for intracerebral involvement, can rarely produce cutaneous and subcutaneous infection. Immunosuppression should be suspected but is not always clinically apparent, as was demonstrated by our case.