Studies on the air-borne fungal spores in Amritsar: Their role in keratomycosis

An aerial survey for fungal spores in Amritsar has been carried out by petri plate exposure method for a period of one year. A total of 23 fungi appeared in the plates. Out of these Aspergillus was the commonest fungus representing 21.69% of the total colony count followed by Alternaria, Curvularia and Fusarium. There was seasonal variation in the prevalence of fungal spores. A comparison of the prevalence of fungi in diseased and healthy eyes and the atmosphere of Amritsar appeasrs to support the view that these fungi are transient residents in the eyes depending on their availability in the atmosphere.Part of the data presented at the XXXVIII All India Ophthalmological Conference held at Amritsar from January 5–8, 1979.     

A comparative study on the airborne fungi in Athens,Greece, by viable and non-viable sampling methods

Airborne fungi were studied in the city of Athens using two complementary methods in which 136 concurrent samplings were carried out during the 12-month period from January until December 1998. A portable Burkard air sampler for agar plates was used for trapping the culturable portion of the mycobiota. Nineteen genera of fungi were identified and assessed in terms of total numbers and fluctuations in concentration (Alternaria, Arthrinium, Aspergillus, Aureobasidium, Botrytis, Chrysonilia, Cladosporium, Drechslera, Epicoccum, Fusarium, Mucor, Nigrospora, Paecilomyces, Penicillium, Rhizopus, Sclerotinia, Scopulariopsis, Trichoderma and Ulocladium), with the exception of those included in the Sphaeropsidales, the yeasts, and the non-sporulating fungi, which were counted as groups. A volumetric Burkard air sampler for glass slides was operating simultaneously for detecting the total mycobiota, including the non-culturable and the non-viable portion. Ascospores, basidiospores, spores of Myxomycetes, Ustilaginales, Uredinales and Erysiphales, teliospores of Puccinia, as well as conidia of the genera Curvularia, Helminthosporium, Periconia, Pestalotiopsis, Pithomyces, Polythrincium, Stachybotrys, Stemphylium and Torula were also recorded. Only seven of the genera were recovered by both samplers. The total numbers of fungal spores, which had a maximum concentration of 3,175 spores/m³, as well as the spore concentrations of the genera Cladosporium (2,565 spores/m³) and Alternaria (280 spores/m³) were underestimated by the viable method (2,435 CFU/m³ for the total, 2,169 CFU/m³ for Cladosporium and 180 CFU/m³ for Alternaria). The non-viable method fails to resolve the identification of the genera Penicillium and Aspergillus, which are major components of the airborne mycobiota (1,068 CFU/m³ and 204 CFU/m³, respectively) based on recovery by the viable method.     

Airborne fungi in an Italian rice mill

Summary Studies employing volumetric spore trap (VSP) and gravity settling culture plates (GSC) were conducted in order to analyse the air spora of a rice mill at Pavia, Italy, from October-December 1988. Results revealed a variety of fungal spores belonging to different genera and including recognized rice pathogenic fungi. The most frequent genera by GSC method includedAcremonium, Alternaria, Aspergillus, Aureobasidium, Cladosporium, Epicoccum, Fusarium, Helminthosporium, Mucor, Nigrospora, Penicillium, Rhizopus, Trichoderma, Trichothecium, and some unidentified fungi. Environmental assessment of fungal spores by VSP revealed that the most prevalent fungi were:Alternaria, Cladosporium, Epicoccum, Helminthosporium, Nigrospora, Pyricularia, Tilletia and hyaline, dark and coloured types of ascospores and basidiospores. Airborne fungal spore concentrations were particularly high (5,000–6,000 spores/m³) in the rooms of the rice mill where the initial stages of rough rice transformation take place, and dropped to 2,500 spores/m³ in the last room, where workers are. During a temporary interruption of the working processes, air spora concentration dropped below 1,000 spores/m³.Cladosporium, Epicoccum andNigrospora spores were predominant in all subdivisions of the indoor environments of the rice mill.     

Allergic potential of someAspergilli on saw mill workers in Lucknow,India

Fifty fungal types were isolated from the indoor atmosphere of saw mills by exposing Petri plates containing Czapek-dox Agar, Potato-dextrose Agar and Sabouraud Agar media for 5 min. The fungal flora of the outdoor surroundings was also studied for comparison. Species ofAspergilli dominated in the saw mills, being represented by 16 species including one ascosporic form. Other fungi were species ofCladosporium, Alternaria, Curvularia, Penicillium, Fusarium, etc. Variations in the fungal population in different months were also observed. Fungal spores recovered using the Rotorod Sampler wereAlternaria, Curvalaria lunata, Curvularia tetramera, Cladosporium, Dreschslera sp.,Epicoccum sp.,Pithomyes sp.,Nigrospora, Stemphylium sp. andTorula sp. Mycelial fragments and unidentifiable spores were also seen in abundance. Varying allergic responses of patients were also recorded by testing intradermally, the antigens of nineAspergilli, vizAspergillus flavus, A. fumigatus, A. japonicus, A. melleus, A. nidulans, A. niger, A. niveus, A. tammarii and A. terreus.     

Allergic potential of someAspergilli on saw mill workers in Lucknow,India

Fifty fungal types were isolated from the indoor atmosphere of saw mills by exposing Petri plates containing Czapek-dox Agar, Potato-dextrose Agar and Sabouraud Agar media for 5 min. The fungal flora of the outdoor surroundings was also studied for comparison. Species ofAspergilli dominated in the saw mills, being represented by 16 species including one ascosporic form. Other fungi were species ofCladosporium, Alternaria, Curvularia, Penicillium, Fusarium, etc. Variations in the fungal population in different months were also observed. Fungal spores recovered using the Rotorod Sampler wereAlternaria, Curvalaria lunata, Curvularia tetramera, Cladosporium, Dreschslera sp.,Epicoccum sp.,Pithomyes sp.,Nigrospora, Stemphylium sp. andTorula sp. Mycelial fragments and unidentifiable spores were also seen in abundance. Varying allergic responses of patients were also recorded by testing intradermally, the antigens of nineAspergilli, vizAspergillus flavus, A. fumigatus, A. japonicus, A. melleus, A. nidulans, A. niger, A. niveus, A. tammarii and A. terreus.     

Colonization capacity of the soil micro-organisms in relation to fungistasis

Summary Evans' tube and cellophane agar-disc techniques were used to evaluate the colonization capacity of the soil microbes and fungistasis, respectively. Spore germination ofAlternaria tenuis, Curvularia geniculata, Helminthosporium rostratum andPestalotia sp. was studied on a natural soil. Aspergillus fumigatus was the pioneer colonizer, followed in the order of decreasing colonizing capacity by,A. flavus, A. niger, A. terreus andPenicillium nigricans. Sensitivity of test spores to soil fungistasis declined in the order,C. geniculata → Pestalotia sp. →A. tenuis → H. rostratum. The fungistatic level of the soil samples decreased gradually from side arms 1 to 7 of the Evans tube, inoculated with unsterilized soil from one end. Studies conducted with an inoculum of four soil fungi (A. fumigatus, A. flavus, A. niger, andP. nigricans) as well as those involving fumigation of Evans tube by CS₂ also proved the greater colonizing capacity ofA. fumigatus. The level of fungistasis followed closely the colonization pattern of this fungus. When added individually to the soil, all fungi were able to inhibit spore germination of test fungi to some degree or other.     

Fungi from otitis media of agricultural field workers

Twenty four fungi were isolated from ear wax or otitis media of agricultural field workers, of which 18 are being reported for the first time from India. Direct observation, revealed the presence of hyphal fragments, spores of Alternaria, Bipolaris, conidial head of Aspergillus, smut teliospores and pollen. Spores of only four fungi, Alternaria humicola, Aspergillus niveus, Bipolaris spicifera and Fusarium moniliforme germinated in otitis media at 37 ° C, and their germination was affected by relative humidity. Alternaria humicola and Aspergillus niveus appeared to be the causative agents of otomycosis, and otitis media is fungistatic in nature.     

Production of Polyclonal and Monoclonal Antibodies Against Hyphae from Arbuscular Mycorrhizal Fungi

Abstract

Polyclonal and monoclonal antibodies were produced against hyphae of the arbuscular mycorrhizal fungus Glomus monosporum. The polyclonal antibodies (pAbs) were raised in a rabbit by immunizing with hyphae. They were tested for their specificity by a dot-immunoblot assay (DIBA). After the third immunization, a distinct difference in the signal strength was observed between the antisera and the preimmune serum. The pAbs showed cross-reactions to a number of fungal species, both mycorrhizal and other. For the production of monoclonal antibodies (mAbs), mice were immunized intraperitoneally with hyphae. The resulting hybridoma cell culture supernatants were tested by an indirect immunolabeling procedure. For this purpose the hyphae were immobilized on silane-coated microscopic slides. The mAb 8A7 reacted with hyphae from all Glomus isolates tested so far. Cross-reactivities were not observed with hyphae from fungi of the family Acaulosporaceae, phytopathogenic fungi tested so far, or from spores from Glomus species.     

Incidence of allergenically significant fungal aerosol in a rural bakery of West Bengal,India

The frequency of fungal spores in the air of three different sections of a rural bakery was analyzed using a Burkard personal slide sampler and Andersen two stage viable sampler. In average concentration of spores (No./m³) was 228–26770/m³ and concentration of viable colony forming units (CFU/m³) was 65-2061 CFU/m³. Dominant fungus species both culturable and nonculturable, were species of Aspergillus and Penicillium, Cladosporiumsp., Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Cladosporium cladosporioides, Penicillium citrinum and Alternaria alternata. Seasonal variations in the spore concentrations were clearly observed in case of some fungi. Total culturable mould concentration of different bakery sections sometimes exceeded the acceptable limit for a healthy indoor environment. Antigenic extracts prepared from some dominant culturable fungi showed high level of allergenicity in skin prick tests indicating that they could be responsible for allergic respiratory dysfunction of bakery workers.This revised version was published online in October 2005 with corrections to the Cover Date.     

Epidemiology of allergic disease: the fungi

Summary In indoor aerial environments and in particular that of homes, the number and type of fungal spores present in the air depend, more than on air exchange with the outside atmosphere, on the presence of sources or dispersion within the building itself. The concentration of spores is half that normally recorded outside the building, withAspergillus, Penicillium, Cladosporium, Alternaria, Mucor, Rhizopus andOidiodendron as the dominating genera. Aerosporological investigations carried out in homes should ideally be done at night, with the exposition of cultural dishes. The repetitive isolation of the same fungus may be particularly important in the etiology of allergic manifestation in man. Particular environments, if insufficiently aerated, with high levels of relative humidity and insufficient illumination, may become ecological niches particularly well suited to fungi, both during its latent form or during a phase of rapid development. Together with rapidly developing fungi, for instanceMucor andRhizopus, slow developing moulds such asPenicillium, Aspergillus andTrichoderma may also be found, characterized however by a production of a great number of easily dispersed conidia. Etiological research into the allergic manifestations of patients continuously inhaling spores responsible for particular allergies appears to be insufficiently developed.     

Arbuscular fungi and mycorrhizae (Glomales) of the Hel Peninsula,Poland

In the years 1985–1989, the occurrence of arbuscular fungi and mycorrhizae on the Hel Peninsula (Poland) was investigated with the help of 45 soil and root samples collected under 20 plant species of eight families. Except for Zea mays, the other plant species were from uncultivated sites. All soil samples contained spores of arbuscular fungi, of which about 45% were of the genus Glomus. Acaulospora spp. preferred members of the Cupressaceae. Spores of Gigaspora occurred rarely and only in two plant families. Glomus spp. were most frequently associated with plants of the Rosaceae, and species of Scutellospora were found at markedly higher frequencies among roots of plants of the Gramineae and Cupressaceae. A total of 29 spore-forming species and Glomus tenue (a fungus recognizable by its distinctive infections) were found. The most frequently recovered fungus, Glomus tenue, was present in roots of 56.8% of examined plants. Of the spore-forming fungi, the most frequently isolated spores were those of Scutellospora dipurpurascens, then Glomus constrictum, Acaulospora 61, and Glomus microcarpum. The overall spore density in examined samples averaged 99.8 in 100 g dry soil in the range 1 to 547, and was highest in a sample taken from around roots of Festuca arundinacea. The dominant fungi forming spores in sampled soils were Glomus constrictum, Glomus microcarpum, and Scutellospora dipurpurascens. The average species density was 3.9 in 100 g dry soil in the range 1 to 10, and was highest in Corynephorus canescens, Rosa canina, and Thuja occidentalis. Levels of colonization by arbuscular fungi ranged from 0.0 to94.0% (mean 23.3%) of the root length and were highest in Festuca arundinaceae and Zea mays.     

Air-borne fungi in the air of Barcelona (Spain). II. The genus Alternaria

The genus Alternaria Nees formed one of the more important components of the fungus population of the air at Barcelone (Spain), during a two-year study, from February 1976 through January 1978. Results were based only on studies of colonies obtained by gravity-exposed plates.The occurrence of this genus was greatly affected by climatic conditions. In general, however, Alternaria appeared to prefer warmer weather.A total of six species of Alternaria was identified, of which, Alternaria alternata (Fries) Keissler was by far the commonest, representing 71.3% of all colonies.     

Production of monoclonal antibodies against surface antigens of spores from arbuscular mycorrhizal fungi by an improved immunization and screening procedure

Monoclonal antibodies (mAbs) were produced against surface antigens of chlamydospores of arbuscular mycorrhizal (AM) fungi by immunizing mice with crushed or complete spores. The intrasplenic approach proved to be superior to the intraperitoneal method of immunization with regard to the amount of antigen required for the immune response. The hybridoma technology was combined with an improved screening procedure, applying an immunogold-silver staining technique to semi-thin sections of spores. In this way, mAbs to surface antigens on the outer wall could be selected. Two mAbs were raised against Glomus etunicatum and G. scintillans spores. Cross-reactivities of the antibodies to other structures of the fungus, to other species of Glomus and to other soil-borne fungi were tested with indirect immunofluorescent labelling. The mAbs did not react with non-AM fungi. One mAb (A5B1) selectively recognized G. etunicatum, another (D12F11) exhibited limited interspecies cross-reactivities. One further mAb (H8F7), which reacted with spores of all AM fungi but not with other fungi, was shown to be specific for Bacillus mycoides. The implications are discussed.     

Airborne fungal spores in the coastal plain of Israel: A preliminary survey

Airborne spores were monitored during the years 1993–1995 in three cities along the coastal plain of Israel: Ramat Gan, Tel Aviv (Ramat Aviv) and Haifa. Seasonal fluctuations in the concentration of airborne spores were recorded. The following genera of fungi were identified:Alternaria, Cladosporium, Coprinus, Curvularia, Drechslera. Diplococcum, Epicoccum, Fusarium, Leptosphaeria, Pithomyces, Puccinia, Sphacelotheca, Stemphylium andUstilago. Unidentified spores were very rare and in negligible numbers. The dominant airborne fungal spores wereCladosporium andAlternaria. The monthly variations in airborne spores, observed among the three cities, seem to be rather minor. The recorded levels of airborne spores were below the concentrations that are accepted as threshold levels for provocation of clinical responses.     

Phylogenetic position of an arbuscular mycorrhizal fungus,Acaulospora gerdemannii, and its synanamorphGlomus leptotichum, based upon 18S rRNA gene sequence

We examined the phylogenetic position of an arbuscular mycorrhizal fungus which produces two types of spore,Acaulospora gerdemannii andGlomus leptotichum, based upon the DNA sequence of the 18S rRNA gene. DNA was extracted separately from bothGlomus-like orAcaulospora-like spores and partial 5′-terminus segments of 18S rRNA gene were amplified by the PCR method. Several clones derived from each spore type were sequenced and compared. The sequences from both spore types agreed well, confirming that these morphologically different spores were formed by the same fungus. Nucleotide substitutions were found among several clones, suggesting polymorphism of the rRNA gene in glomalean fungi. Further phylogenetic analysis based upon the whole sequence of the 18S rRNA gene showed thatA. gerdemannii may be within the order Glomales but is far from the fungi that have been analyzed and probably should be in a new family.     

Flavonoids induce germination of basidiospores of the ectomycorrhizal fungus <Emphasis Type="Italic">Suillus bovinus</Emphasis>

Under laboratory conditions, spores of ectomycorrhizal fungi usually germinate very poorly or not at all. In a previous study, we showed that spores of the ectomycorrhizal fungus Suillus bovinus germinated through the combination of activated charcoal treatment of media and co-culture with seedlings of Pinus densiflora, which suggested that some substances contained in root exudates induced the germination. Among the compounds reported from root exudates, flavonoids have been elucidated to play various and substantial roles in plant–microbe interactions; we therefore investigated the effects of flavonoids on basidiospore germination of S. bovinus by the diffusion gradient assay on water agar plates pretreated with charcoal powder. Seven out of the 11 flavonoids tested, hesperidin, morin, rutin, quercitrin, naringenin, genistein, and chrysin, had greater effects than controls, whereas flavone, biochanin A, luteolin, and quercetin showed no positive effects. The effective concentration presumably corresponded to several micromolar levels, which was equivalent to those effective for pollen development, nod gene induction, and spore germination of F. solani f. sp. pisi and AM fungi. The results suggest that flavonoids play a role as signaling molecules in symbiotic relationships between woody plants and ectomycorrhizal fungi.     

Development,Distribution, and Host Studies of the Fungus Macrobiotophthoira vermicola (Entomophthorales)

The life cycle and host range of Macrobiotophthora vermicola were studied. Secondary spores produced from forcibly ejected primary spores adhered to the cuticle of Cruznema tripartitum, germinated, and penetrated the cuticle within 30 minutes. New primary spores were produced within 24 hours of initial spore adhesion. In a host range study, species of Rhabditidae, Diplogasteridae, and Aphelenchoidea were hosts, but not species of Bunonematidae, Tripylidae, Cephalobida, or Tylenchina. Numbers of second-stage Meloidogyne incognita juveniles were not decreased when added to soil seeded with infected C. tripartitum. In six Tennessee soybean fields, Macrobiotophthora vermicola was the most commonly encountered nematode-destroying fungus, followed by a sterile, nonseptate fungus and Arthrobotrys conoides. Nematophagous fungi were isolated more frequently from silt loam soils than from clay soils. Addition of C. tripartitum to soil extract plates as a bait nematode did not increase isolations of nematophagous fungi.     

Assessment of arbuscular mycorrhizal fungi diversity in the rhizosphere of <Emphasis Type="Italic">Viola calaminaria</Emphasis> and effect of these fungi on heavy metal uptake by clover

 The ability of arbuscular mycorrhizal (AM) fungi from a metal-tolerant plant (Viola calaminaria, violet) to colonise and reduce metal uptake by a non-tolerant plant (Trifolium subterraneum, subterranean clover) in comparison to a metal-tolerant AM fungus isolated from a non-tolerant plant was studied. AM spores from the violet rhizosphere and from violet roots were characterised by polymerase chain reaction (PCR) amplification of the SSU rDNA, and sequencing. Subterranean clover was grown in pots containing a soil supplemented with Cd and Zn salts and inoculated either with a mixture of spores extracted from the violet rhizosphere or with spores of a Cd-tolerant Glomus mosseae P2 (BEG 69), or non-inoculated. The diversity of fungi, including AM fungi, colonising clover roots was assessed and analysed using terminal-restriction fragment length polymorphism. At least four different Glomus species were found in the violet rhizosphere. After 8 weeks in a growth chamber, colonisation of clover roots with spores from the violet rhizosphere increased Cd and Zn concentrations in clover roots without significantly affecting the concentrations of metals in the shoot and plant growth. G. mosseae P2 reduced plant growth and slightly increased the Cd concentration. Only one AM fungus (Glomus b) from the violet rhizosphere colonised clover roots, but other fungi were present. AM fungi from heavy metal-contaminated soils and associated with metal-tolerant plants may be effective in accumulating heavy metals in roots in a non-toxic form. Accepted: 7 July 2000     

The influence of nitrogen nutrition on growth and sporulation of alternaria solani (Ell. & Mart.) jones & grout

Summary Alternaria solani causing a severe leaf spot disease ofSolanum melongena L. was able to metabolize a variety of nitrogen compounds when grown in a chemically defined medium in surface culture. The amount of growth varied with the nitrogen source. Peptone produced the greatest growth of the fungus. Ammonium compounds were found to be moderately effective for growth, but poor for the formation of the spores.     

Specimen preparation for high contrast image processing and fractal analysis of branching fungal colonies

Summary A rapid method is presented for the aerosol dispersion of fungal spores onto microporous polycarbonate membrane overlays in petri-dish agar culture, using an air-brush apparatus. Nebulizer inoculation results in the growth from single spores of discrete, filamentous colonies which can be immobilized, fixed, and stainedin situ using Coomassie Brilliant Blue R. High contrast microscopy and image-processing is facilitated using Poretics Cyto-Clear^™ glass slides. This technique was developed specifically for the fractal analysis of branching and the measurement of other morphological parameters in fungi. Emphasis is directed towards the ligninolytic fungi,Pycnoporus cinnabarinus andPhanerochaete chrysosporium.