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1.
Microbiology (Reading) ; 167(2)2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33427606

RESUMO

Chlamydoconidium-producing Trichophyton tonsurans strains isolated in Northeastern Brazil have morphological features different from the classic description of this dermatophyte species. This study investigated the phylogenetic relationship of chlamydoconidium-producing T. tonsurans strains isolated in Northeastern Brazil. Also, the effect of terbinafine and farnesol on mature biofilms of T. tonsurans strains was evaluated. The mass spectra of T. tonsurans strains were investigated by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The ITS and LSU loci regions of rDNA and the partial ß-tubulin gene were sequenced and the phylogenetic tree was analysed. The effects of terbinafine and farnesol on mature T. tonsurans biofilms were evaluated through the analysis of metabolic activity, quantification of biomass and observation by scanning electron microscopy. MALDI-TOF MS spectra of the chlamydoconidium-producing T. tonsurans strains differed from the spectrum of the control strain (ATCC 28942), presenting an intense ion peak at m/z 4155 Da. Phylogenetic tree analysis showed that the chlamydoconidium-producing strains isolated in Northeastern Brazil are allocated to a single cluster, differing from strains isolated from other countries. As for mature T. tonsurans biofilms, farnesol reduced biomass and metabolic activity by 64.4 and 65.9 %, respectively, while terbinafine reduced the biomass by 66.5 % and the metabolic activity by 69 %. Atypical morphological characteristics presented by chlamydoconidium-producing T. tonsurans strains result from phenotypic plasticity, possibly for adaptation to environmental stressors. Also, farnesol had inhibitory activity against T. tonsurans biofilms, demonstrating this substance can be explored for development of promising anti-biofilm drugs against dermatophytes.


Assuntos
Antifúngicos/farmacologia , Arthrodermataceae/classificação , Biofilmes/efeitos dos fármacos , Filogenia , Arthrodermataceae/citologia , Arthrodermataceae/efeitos dos fármacos , Arthrodermataceae/fisiologia , Biofilmes/crescimento & desenvolvimento , Brasil , DNA Fúngico/genética , DNA Ribossômico/genética , Farneseno Álcool/farmacologia , Proteínas Fúngicas/genética , Humanos , Testes de Sensibilidade Microbiana , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Esporos Fúngicos/classificação , Esporos Fúngicos/citologia , Terbinafina/farmacologia , Tubulina (Proteína)/genética
2.
J Appl Microbiol ; 131(1): 449-459, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33058340

RESUMO

AIMS: This study aimed to evaluate the effects of three Bacillus probiotics on Salmonella Typhimurium, and interleukin-8 (IL-8) gene expression in the co-culture of the Bacillus and the pathogen in vitro. METHODS AND RESULTS: Bacillus subtilis, Bacillus indicus and Bacillus coagulans were initially turned to spore and heat-inactivated forms. The cellular damages of the probiotics on the HT-29 cells were investigated individually and in combination with S. Typhimurium using 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and fluorescence assays. To extract cell free supernatants (CFS) of the probiotics, they were cultured in selective media. The inhibitory activity of CFSs were then assayed against the pathogen. The gene expression of IL-8 of the HT-29 cells was evaluated by real-time PCR in all the groups. The results showed that the CFSs of three probiotics could inhibit the growth of S. Typhimurium by more than 50%. Inhibitory effects of B. indicus and B. subtilis CFSs were related to the production of pepsin-sensitive compounds, except B. coagulans in which the high inhibitory effect was due to organic acids. The spores of the three probiotics and the heat-inactivated forms of B. subtilis and B. coagulans could reduce the cytotoxicity of S. Typhimurium. The cell viability also increased applying both forms probiotics against the pathogen. In all co-culture groups, the IL-8 gene expression induced by S. Typhimurium was reduced. CONCLUSIONS: The three Bacillus probiotics can be considered as proper candidates for the prevention and treatment of S. Typhimurium food poisoning. SIGNIFICANCE AND IMPACT OF THE STUDY: Applying probiotics as live bacteria is universally noted in foods. This study tried to discover the effects of Bacillus probiotics in the form of spore or even heat-killed bacteria against S. Typhimurium and evaluate ratio of IL-8 gene expression in cell culture. The most effective Bacillus probiotic will be recommended. This approach will help to use probiotics as nonvegetative cells in foods to fight gastrointestinal pathogens.


Assuntos
Apoptose/efeitos dos fármacos , Bacillus/fisiologia , Interleucina-8/genética , Probióticos/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Bacillus/classificação , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Expressão Gênica/efeitos dos fármacos , Células HT29 , Humanos , Interleucina-8/metabolismo , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/patogenicidade , Esporos Fúngicos/classificação , Esporos Fúngicos/fisiologia
3.
J Sci Food Agric ; 101(14): 5834-5841, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33788958

RESUMO

BACKGROUND: The harmful effect of chemical fertilizer application on human health and the environment as a modern method of meeting the food demand of the increasing world population demands an urgent alternative that is environmentally friendly, which will pose no harm to human health and the environment. Arbuscular mycorrhizal fungi (AMF) are beneficial soil microorganisms that provide various ecological functions in increasing soil fertility and enhancing plant growth. This present study aimed to propagate, characterize and examine the effect of viable arbuscular mycorrhizal fungal spores on maize (Zea mays L) hosts using molecular methods. The propagation of AMF in the host plant using sterile soil and vermiculite was conducted in the greenhouse. RESULT: The effect of AMF inoculation revealed a significant difference (P > 0.05) in maize growth, root colonization and AMF spore count when compared with the control. In all the parameters measured in this study, all the AMF spores propagated had a positive effect on the maize plant over the control, with the highest value mostly recorded in Rhizophagus irregularis AOB1. The molecular characterization of the spore using a specific universal primer for Glomeromycota established the success of the propagation process, which enhanced the classification of the AMF species into Rhizophagus irregularis OAB1, Glomus mosseae OAB2 and Paraglomus occultum OAB3. CONCLUSION: This finding will be a starting point in producing arbuscular mycorrhizal inoculum as a biofertilizer to enhance plant growth promotion. © 2021 Society of Chemical Industry.


Assuntos
Fungos/isolamento & purificação , Micorrizas/isolamento & purificação , Esporos Fúngicos/crescimento & desenvolvimento , Zea mays/microbiologia , Fungos/classificação , Fungos/genética , Fungos/crescimento & desenvolvimento , Micorrizas/classificação , Micorrizas/genética , Micorrizas/crescimento & desenvolvimento , Filogenia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Microbiologia do Solo , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/isolamento & purificação , Zea mays/crescimento & desenvolvimento
4.
Med Mycol ; 58(1): 118-123, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30980083

RESUMO

Mucormycosis is an angio-invasive infection, predominantly acquired by inhalation of sporangiospores from the environment. However, the burden of Mucormycetes sporangiospores in the air is not well studied. We aimed to estimate the burden of Mucormycetes spores in the outdoor and indoor (hospital) environment across different seasons in north India. A total of 380 air samples from outdoor (n = 180) and indoor (n = 200) environment were included in the study. Air samples were suctioned using air sampler (100 l/min) and cultured on Dichloran Rose Bengal Chloramphenicol (DRBC) with benomyl for selective isolation of Mucormycetes. The isolates were identified by phenotypic and genotypic methods. The mean spore count (±SD) of Mucormycetes (cfu/m3) in outdoor samples varied from 0.73 (±0.96) to 8.60 (±5.70) across different seasons. In hospital, the mean spore count varied from 0.68 (±1.07) to 1.12 (±1.07) and 0.88 (±1.01) to 1.72 (±2.17) for air-conditioned wards and non-air-conditioned wards, respectively. Rhizopus arrhizus was the predominant agent isolated from both indoor and outdoor environment followed by Cunninghamella species. We also report a single isolate of the rare mucormycete agent, Apophysomyces variabilis from outdoor environment. The present study highlights the presence of low spore burden of Mucormycetes in outdoor and hospital settings in north India. This study also reports the first isolation of A. variabilis from air samples in the Indian subcontinent.


Assuntos
Microbiologia do Ar , Poluição do Ar em Ambientes Fechados , Hospitais , Mucorales/isolamento & purificação , Estações do Ano , Esporos Fúngicos/isolamento & purificação , Contagem de Colônia Microbiana , Genótipo , Índia , Mucorales/classificação , Fenótipo , Esporos Fúngicos/classificação
5.
J Appl Microbiol ; 129(5): 1337-1348, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32406554

RESUMO

AIMS: A real-time quantitative PCR (qPCR) assay was established to quantify the inoculum densities in the air and rainwater for six canker-causing pathogen groups in prune and walnut orchards in California. METHODS AND RESULTS: The previously published DNA primers to target six pathogen groups including Botryosphaeria dothidea, Cytospora spp., Diplodia spp., Lasiodiplodia spp., Neofusicoccum spp. and Phomopsis spp. were used in a qPCR assay. Air samples from Burkard spore traps and rain samples from special rain collector devices were collected periodically from various prune and walnut orchards. Using the qPCR approach, we were able to quantify the concentrations of these pathogen groups in rainwater and air samples and study the dynamics of pathogen inoculum in orchards showing severe canker potential. Phomopsis spp. and Diplodia spp. were not found in all rain samples in prune orchards, although they were detected in the 2016 in the walnut orchard. The other four pathogen groups were quantified at varying concentrations in the prune and walnut orchards. Cytospora spp. in some cases showed higher concentrations in the rainwater in prune orchards. CONCLUSIONS: The rainy season during winter and early spring is a highly risky period of time for infection by the pathogens when the inoculum of these pathogens can easily spread by air and rain water, thus serving as an important inoculum source for disease initiation. The different studied pathogen groups showed different concentrations during the growing season, indicating the complexity of the components of canker-causing species in various tree crops. SIGNIFICANCE AND IMPACT OF THE STUDY: This study showed the applicability of the qPCR assay in the quantification of inoculum in tree orchards to help reveal the mechanisms of canker disease epidemics and to help design disease management strategies.


Assuntos
Ascomicetos/isolamento & purificação , Fazendas/estatística & dados numéricos , Juglans/microbiologia , Doenças das Plantas/microbiologia , Prunus/microbiologia , Microbiologia do Ar , Ascomicetos/classificação , Ascomicetos/genética , Produtos Agrícolas/microbiologia , Chuva/microbiologia , Reação em Cadeia da Polimerase em Tempo Real , Estações do Ano , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/isolamento & purificação
6.
J Appl Microbiol ; 129(2): 400-410, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32043673

RESUMO

AIMS: To isolate and characterize a native strain of Trichothecium roseum infecting the immatures of Pauropsylla buxtoni on fig leaves, to study the morphological features of the isolated strain, then to test the entomopathogenic effect of the isolated strain against the immatures of P. buxtoni on fig leaves. METHODS AND RESULTS: The isolated strain of T. roseum produced pink mycelial growth on culture medium with septate mycelium and conidiophores. It also produced two-celled conidia with elliptical to pyriform shape born at the tip of conidiophores. Molecular characterization of the isolated strain confirmed the identity of the strain as T. roseum. In bioassays, application of conidial suspension of the isolated strain against the 4th instar of P. buxtoni immatures infesting fig leaves showed an obvious entomopathogenic effect of the applied fungus strain against the targeted insect. This effect was exhibited by the death of treated P. buxtoni immatures with the fungus. The dead insects were characterized by the presence of pinkish mycelial growth on the outer surface which is characteristic to the fungus, in addition to the positive isolation of the fungus from internal tissues of treated insects after a proper external disinfection. Moreover, significant differences (at P < 0·018) were obtained between the means of mortality % of P. buxtoni immatures treated with different concentrations of conidial suspension of the fungus. CONCLUSIONS: The overall results confirm the entomopathogenic effect of T. roseum against P. buxtoni immatures infesting fig leaves. Significant mortalities of P. buxtoni immatures were obtained when the different concentrations of the fungus conidial suspension were bio-assessed against the insect. SIGNIFICANCE AND IMPACT OF THE STUDY: The tested strain of T. roseum can be applied as biocontrol agent of P. buxtoni on fig leaves within an integrated control programme to reduce the impact of pest on fig trees.


Assuntos
Ficus/parasitologia , Hemípteros/microbiologia , Hypocreales/patogenicidade , Controle Biológico de Vetores/métodos , Doenças das Plantas/prevenção & controle , Animais , Hemípteros/crescimento & desenvolvimento , Hypocreales/classificação , Hypocreales/citologia , Hypocreales/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/microbiologia , Doenças das Plantas/parasitologia , Folhas de Planta/parasitologia , Esporos Fúngicos/classificação , Esporos Fúngicos/citologia , Esporos Fúngicos/crescimento & desenvolvimento
7.
Appl Microbiol Biotechnol ; 104(13): 5689-5695, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32382933

RESUMO

RNA editing occurs in all kingdoms of life and in various RNA species. The editing of nuclear protein-coding transcripts has long been known in metazoans, but was only recently detected in fungi. In contrast to many metazoan species, fungal editing sites occur mostly in coding regions, and therefore, fungal editing can change protein sequences and lead to modified or new functions of proteins. Indeed, mRNA editing is thought to be generally adaptive on fungi. Although RNA editing has been detected in both, Ascomycota and Basidiomycota, there seem to be considerable differences between these two classes of fungi concerning the types, the timing, and the purpose of editing. This review summarizes the characteristics of RNA editing in fungi and compares them to metazoan species and bacteria. In particular, it will review cellular processes affected by editing and speculate on the purpose of editing for fungal biology with a focus on the filamentous ascomycetes. KEY POINTS: • Fungi show various types of mRNA editing in nuclear transcripts. • Fungal editing leads to proteome diversification. • Filamentous ascomycetes may require editing for sexual sporulation. • Wood-degrading basidiomycetes may use editing for adaptation to different substrates.


Assuntos
Fungos/genética , Edição de RNA , RNA Fúngico/genética , RNA Mensageiro/genética , Adaptação Fisiológica , Ascomicetos/genética , Ascomicetos/metabolismo , Ascomicetos/fisiologia , Evolução Biológica , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fungos/classificação , Fungos/metabolismo , Fungos/fisiologia , Regulação Fúngica da Expressão Gênica , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/fisiologia
8.
Appl Microbiol Biotechnol ; 104(13): 5711-5724, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32405755

RESUMO

Formulated conidia of insect-pathogenic fungi, such as Beauveria and Metarhizium, serve as the active ingredients of fungal insecticides but are highly sensitive to persistent high temperatures (32-35 °C) that can be beyond their upper thermal limits especially in tropical areas and during summer months. Fungal heat tolerance and inter- or intra-specific variability are critical factors and limitations to field applications of fungal pesticides during seasons favoring outbreaks of pest populations. The past decades have witnessed tremendous advances in improving fungal pesticides through selection of heat-tolerant strains from natural isolates, improvements and innovations in terms of solid-state fermentation technologies for the production of more heat-tolerant conidia, and the use of genetic engineering of candidate strains for enhancing heat tolerance. More recently, with the entry into a post-genomic era, a large number of signaling and effector genes have been characterized as important sustainers of heat tolerance in both Beauveria and Metarhizium, which represent the main species used as fungal pesticides worldwide. This review focuses on recent advances and provides an overview into the broad molecular basis of fungal heat tolerance and its multiple regulatory pathways. Emphases are placed on approaches for screening of heat-tolerant strains, methods for optimizing conidial quality linked to virulence and heat tolerance particularly involving cell wall architecture and optimized trehalose/mannitol contents, and how molecular determinants can be exploited for genetic improvement of heat tolerance and pest-control potential. Examples of fungal pesticides with different host spectra and their appropriateness for use in apiculture are given. KEY POINTS: • Heat tolerance is critical for field stability and efficacy of fungal insecticides. • Inter- and intra-specific variability exists in insect-pathogenic fungi. • Optimized production technology and biotechnology can improve heat tolerance. • Fungal heat tolerance is orchestrated by multiple molecular pathways.


Assuntos
Fungos/fisiologia , Inseticidas , Controle Biológico de Vetores , Termotolerância/genética , Animais , Parede Celular/metabolismo , Fungos/classificação , Fungos/genética , Fungos/metabolismo , Genes Fúngicos , Engenharia Genética , Variação Genética , Manitol/metabolismo , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/metabolismo , Trealose/metabolismo
9.
Mycoses ; 63(3): 275-283, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31774582

RESUMO

BACKGROUND: The sister yeast species Cryptococcus neoformans (serotype A) and Cryptococcus deneoformans (serotype D) are causative agents of deadly cryptococcosis and fungal meningoencephalitis. These haploid yeasts can hybridise in nature, giving rise to AD hybrids that are predominantly diploid or aneuploid. Despite their increasing prevalence in clinical settings, much remains unknown about the allelic distribution patterns in AD hybrid strains. OBJECTIVES: This study aims to characterise allele distributions in AD hybrids derived from the same basidium as well as from multiple basidia in a laboratory-derived C neoformans × C deneoformans hybrid cross. METHODS: We dissected a total of 1625 basidiospores from 31 basidia. The 297 basidiospores that successfully germinated were genotyped by molecular characterisation of 33 markers using PCR-RFLP, with at least two markers on each of the 14 chromosomes in the genome. RESULTS: Of the 297 strains, 294 contained at least one heterozygous locus, with a mean heterozygosity of ~30% per strain. Most hybrid genomes and chromosomes displayed significantly distorted allele distributions, with offspring originating from the same basidium tended to have alleles at different loci from the same parent. More basidia were skewed in favour of C deneoformans alleles, the mitochondria-donor parent, than the C neoformans alleles. CONCLUSIONS: The divergence between C neoformans and C deneoformans genomes has likely created co-adapted allelic combinations, with their co-segregation in hybrid offspring imparting a significant fitness benefit. However, the diversity of genotypes recovered here in a single hybridisation event indicates the enormous capacity of AD hybrids for adaptation and diversification.


Assuntos
Alelos , Criptococose/microbiologia , Cryptococcus neoformans/genética , Cryptococcus/genética , Meningoencefalite/microbiologia , Aneuploidia , Distribuição de Qui-Quadrado , Cryptococcus/classificação , Cryptococcus neoformans/classificação , Diploide , Marcadores Genéticos , Estudo de Associação Genômica Ampla , Genótipo , Técnicas de Genotipagem , Heterozigoto , Hibridização Genética , Perda de Heterozigosidade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Esporos Fúngicos/classificação , Esporos Fúngicos/genética
10.
J Invertebr Pathol ; 174: 107399, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32473942

RESUMO

Two types of secondary conidia and their formation are described from six species of Strongwellsea infecting hosts from Anthomyiidae, Muscidae and Fanniidae. We used a simple device allowing secondary conidia to be produced under very moist or comparatively dry conditions. Ellipsoid type secondary conidia, which are formed under very moist conditions, have never been reported before from the genus Strongwellsea, and they are unique for Entomophthorales; these are broadly ellipsoidal with a clearly pointed basal papilla and are actively discharged. Subglobose type secondary conidia are, for the first time, described from several species in the genus Strongwellsea; they are subglobose to almost bell-shaped with a flattened papilla and are actively discharged. Subglobose type secondary conidia are formed under more dry conditions. A general pattern of the formation of secondary conidia in Strongwellsea and the ecological roles of primary conidia and of the two types of secondary conidia are discussed.


Assuntos
Dípteros/microbiologia , Entomophthorales/fisiologia , Esporos Fúngicos/citologia , Animais , Esporos Fúngicos/classificação
11.
Parasitol Res ; 119(3): 915-923, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31970472

RESUMO

A new species and a new genus of a microsporidium Alternosema bostrichidis isolated from an adult Prostephanus truncatus in Mexico and from three species of the genus Dinoderus in Nigeria are described. The microsporidium is monomorphic, monoxenic, and develops in direct contact with host cell cytoplasm. The infection first appears with thoracic muscles, followed by a generalized invasion of the host. All developmental stages are diplokaryotic. Sporogony is disporoblastic. Mature spores are ovoid. Unfixed spores measure 3.7-4.2 × 2.0-2.6 µm, fixed and stained spores 3.5-5.0 × 2.4-2.8 µm. The polaroplast consists of dense lamellae and rare lamellae. The polar tube is slightly anisofilar, consisting of 11-17 coils, with 9-14 proximal (130 nm in diameter) and 2-3 distal coils (120 nm in diameter) arranged in one layer. Molecular phylogenetic analysis based upon a short portion of small-subunit ribosomal RNA gene (Genbank accession # KP455651) placed the new microsporidium within Liebermannia-Orthosomella lineage, which contains multiple undescribed parasites. In particular, A. bostrichidis showed maximal sequence similarity of 95% to Microsporidium sp. BBRE2 (# FJ755987) from Baikalian Diplacanthus brevispinus (Amphipoda: Acanthogammaridae) and Microsporidium sp. Comp CD Van 2 (# KC111784) from compost and soil in Canada. Frequent, devastating epizootics of laboratory cultures of A. bostrichidis support its potential as a biological control agent of grain borers.


Assuntos
Anfípodes/microbiologia , Agentes de Controle Biológico , Besouros/microbiologia , Microsporídios não Classificados/classificação , Microsporídios não Classificados/isolamento & purificação , Animais , Canadá , México , Microsporídios não Classificados/genética , Nigéria , Filogenia , Prevalência , Esporos Fúngicos/classificação
12.
Antonie Van Leeuwenhoek ; 112(5): 753-764, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30535961

RESUMO

Stypella vermiformis is a heterobasidiomycete producing minute gelatinous basidiocarps on rotten wood of conifers in the Northern Hemisphere. In the current literature, Stypella papillata, the genus type of Stypella (described from Brazil), is treated as a taxonomic synonym of S. vermiformis. In the present paper, we revise the type material of S. papillata and a number of specimens addressed to S. vermiformis. As a result, the presumed synonymy of S. papillata and S. vermiformis is rejected and the genus Stypella is restricted to the single species S. papillata. Morphological and molecular phylogenetic studies of specimens from the Northern Hemisphere corresponding to the current concept of S. vermiformis uncovered three species from two newly described genera. S. vermiformis s.str. is distributed in temperate Europe and has small-sized basidia and basidiospores, and it is placed in a new genus, Mycostilla. Another genus, Stypellopsis, is created for two other species, the North American Stypellopsis farlowii, comb. nov., and the North European Stypellopsis hyperborea, sp. nov. Basidia and basidiospores of Stypellopsis spp. are larger than in Mycostilla vermiformis but other morphological characters are very similar. In addition, Spiculogloea minuta (Spiculogloeomycetes, Pucciniomycotina) is reported as new to Norway, parasitising basidiocarps of M. vermiformis and Tulasnella spp.


Assuntos
Basidiomycota/classificação , Basidiomycota/genética , Basidiomycota/crescimento & desenvolvimento , Basidiomycota/isolamento & purificação , Brasil , Europa (Continente) , Noruega , Filogenia , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/isolamento & purificação
13.
PLoS Genet ; 12(5): e1006017, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27153332

RESUMO

Drechmeria coniospora is an obligate fungal pathogen that infects nematodes via the adhesion of specialized spores to the host cuticle. D. coniospora is frequently found associated with Caenorhabditis elegans in environmental samples. It is used in the study of the nematode's response to fungal infection. Full understanding of this bi-partite interaction requires knowledge of the pathogen's genome, analysis of its gene expression program and a capacity for genetic engineering. The acquisition of all three is reported here. A phylogenetic analysis placed D. coniospora close to the truffle parasite Tolypocladium ophioglossoides, and Hirsutella minnesotensis, another nematophagous fungus. Ascomycete nematopathogenicity is polyphyletic; D. coniospora represents a branch that has not been molecularly characterized. A detailed in silico functional analysis, comparing D. coniospora to 11 fungal species, revealed genes and gene families potentially involved in virulence and showed it to be a highly specialized pathogen. A targeted comparison with nematophagous fungi highlighted D. coniospora-specific genes and a core set of genes associated with nematode parasitism. A comparative gene expression analysis of samples from fungal spores and mycelia, and infected C. elegans, gave a molecular view of the different stages of the D. coniospora lifecycle. Transformation of D. coniospora allowed targeted gene knock-out and the production of fungus that expresses fluorescent reporter genes. It also permitted the initial characterisation of a potential fungal counter-defensive strategy, involving interference with a host antimicrobial mechanism. This high-quality annotated genome for D. coniospora gives insights into the evolution and virulence of nematode-destroying fungi. Coupled with genetic transformation, it opens the way for molecular dissection of D. coniospora physiology, and will allow both sides of the interaction between D. coniospora and C. elegans, as well as the evolutionary arms race that exists between pathogen and host, to be studied.


Assuntos
Caenorhabditis elegans/microbiologia , Micoses/microbiologia , Filogenia , Spiroplasma/genética , Animais , Ascomicetos/genética , Ascomicetos/patogenicidade , Caenorhabditis elegans/parasitologia , Hibridização Genômica Comparativa , Hypocreales/classificação , Hypocreales/genética , Micoses/parasitologia , Spiroplasma/classificação , Spiroplasma/patogenicidade , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/patogenicidade , Virulência/genética
14.
J Basic Microbiol ; 59(6): 645-657, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30900744

RESUMO

This study aims to investigate the molecular phylogenetic analysis, morphological variability, nematode-capturing ability, and other biological properties of Chinese Duddingtonia flagrans isolates. We isolated 13 isolates of D. flagrans and found features that have never been reported before, such as two to three septa incluing club-shaped conidia. Meanwhile, we conducted molecular phylogenetic analysis of the seven isolates and tested the radical growth of the isolates under different pH values, temperatures, and media. The capturing ability against infective larvae (L3) of Cooperia spp. in yak was detected in vitro. Finally, one isolate was selected for scanning electron microscopy (SEM) to investigate the trap formation process. The fungal sequence was obtained and submitted to GenBank (Accession no. KY288614.1, KU881774.1, KP257593.1, KY419119.1, MF488979.1, MF488980.1, and MF488981.1), and the tested isolates were identified as D. flagrans. Except for three isolates, the radial growth of the other isolates on 2% corn meal agar and 2% water agar exhibited faster growth than on other media. The fungus could not grow at 10 and 40°C but grew within 11 to 30°C. Moreover, it did not grow at pH 1-3 and 13-14, but instead at pH 4-12. In the in vitro experimental, L3s were reduced by 94.36%, 88.15%, and 91.04% for SDH035, DH055, and F088, respectively. SEM results showed that at 8 hr post addition of nematodes, some of the latter were captured. In the later stages of the interaction of the fungus with nematodes, a large number of chlamydospores were produced, especially on the predation trap. Results of the present study provided information about the molecular phylogenetic analysis, morphological variability, nematode-capturing ability, and other biological properties of Chinese Arthrobotrys flagrans isolates before administering them for biocontrol.


Assuntos
Duddingtonia/classificação , Duddingtonia/fisiologia , Interações Hospedeiro-Patógeno , Filogenia , Trichostrongyloidea/microbiologia , Animais , Bovinos , DNA Fúngico/genética , DNA Ribossômico/genética , Duddingtonia/ultraestrutura , Fezes/parasitologia , Concentração de Íons de Hidrogênio , Larva/microbiologia , Microscopia Eletrônica de Varredura , Controle Biológico de Vetores , Análise de Sequência de DNA , Esporos Fúngicos/classificação , Esporos Fúngicos/fisiologia , Esporos Fúngicos/ultraestrutura , Temperatura
15.
Anal Chem ; 90(15): 8912-8918, 2018 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-29956919

RESUMO

Fungal spores are one of several environmental factors responsible for causing respiratory diseases like asthma, chronic obstructive pulmonary disease (COPD), and aspergillosis. These spores also are able to trigger exacerbations during chronic forms of disease. Different fungal spores may contain different allergens and mycotoxins, therefore the health hazards are varying between the species. Thus, it is highly important quickly to identify the composition of fungal spores in the air. In this study, UV-Raman spectroscopy with an excitation wavelength of 244 nm was applied to investigate eight different fungal species implicated in respiratory diseases worldwide. Here, we demonstrate that darkly colored spores can be directly examined, and UV-Raman spectroscopy provides the information sufficient for classifying fungal spores. Classification models on the genus, species, and strain levels were built using a combination of principal component analysis and linear discriminant analysis followed by evaluation with leave-one-batch-out-cross-validation. At the genus level an accuracy of 97.5% was achieved, whereas on the species level four different Aspergillus species were classified with 100% accuracy. Finally, classifying three strains of Aspergillus fumigatus an accuracy of 89.4% was reached. These results demonstrate that UV-Raman spectroscopy in combination with innovative chemometrics allows for fast identification of fungal spores and can be a potential alternative to currently used time-consuming cultivation.


Assuntos
Fungos/classificação , Análise Espectral Raman/métodos , Esporos Fúngicos/classificação , Aspergilose/microbiologia , Aspergillus/química , Aspergillus/classificação , Aspergillus fumigatus/química , Aspergillus fumigatus/classificação , Asma/microbiologia , Análise Discriminante , Desenho de Equipamento , Fungos/química , Humanos , Análise de Componente Principal , Doença Pulmonar Obstrutiva Crônica/microbiologia , Análise Espectral Raman/instrumentação , Esporos Fúngicos/química , Raios Ultravioleta
16.
J Eukaryot Microbiol ; 65(3): 427-431, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29171125

RESUMO

Microsporidia-like spores (2.0-3.0 × 1.3-1.5 µm) were discovered upon examination of histological sections taken from Phoronis embryolabi Temereva, Chichvarkhin 2017 found inhabiting burrows of shrimps Nihonotrypeae japonica (Decapoda, Callianassidae) from the Sea of Japan, Russia. Ultrastructural examination of spores revealed one nucleus and a uniform polar filament of 7-11 coils. Representatives of the phylum Phoronida have never been recorded as hosts of microsporidia. Parasites developed in vasoperitoneal tissue and caused formation of multinucleate syncytia. Basing on unique host and fine morphology, we assign the novel finding to Microsporidium phoronidi n. sp. and place provisionally in the collective genus Microsporidium.


Assuntos
Decápodes/parasitologia , Invertebrados/microbiologia , Microsporídios não Classificados/classificação , Microsporídios não Classificados/isolamento & purificação , Esporos Fúngicos/classificação , Animais , Microscopia Eletrônica de Transmissão , Filogenia , Federação Russa
17.
Antonie Van Leeuwenhoek ; 111(12): 2323-2347, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29980901

RESUMO

Species of Leptographium are characterized by mononematous or synnematous conidiophores and are commonly associated with different arthropods. Some of them also produce a sexual state characterised by globose ascomata with elongated necks. Compared to investigations on coniferous trees, the occurrence of Leptographium species on hardwood trees has been poorly studied in Europe. During a survey of ophiostomatoid fungi on various hardwood tree species in Norway and Poland, three unusual species, which fit in the broader morphological description of Leptographium spp., were found in association with Trypodendron domesticum, Trypodendron signatum and Dryocoetes alni, and from wounds on a variety of hardwoods. Phylogenetic analyses of sequence data for six different loci (ITS1-5.8 S-ITS2, ITS2-LSU, ACT, ß-tubulin, CAL, and TEF-1α) showed that these Leptographium species are phylogenetically closely related to the species of the Grosmannia olivacea complex. The first species forms a well-supported lineage that includes Ophiostoma brevicolle, while the two other new taxa resided in a separate lineage; possibly affiliated with Grosmannia francke-grosmanniae. All the new species produce perithecia with necks terminating in ostiolar hyphae and orange-section shaped ascospores with cucullate, gelatinous sheaths. These species also produce dark olivaceous mononematous asexual states in culture. In addition, two of the newly described species have a second type of conidiophore with a short and non-pigmented stipe. The new Leptographium species can be easily distinguished from each other by their appearance and growth in culture. Based on novel morphological characters and distinct DNA sequences, these fungi were recognised as new taxa for which the names Leptographium tardum sp. nov., Leptographium vulnerum sp. nov., and Leptographium flavum sp. nov. are provided.


Assuntos
Alnus/microbiologia , DNA Fúngico/genética , Fagus/microbiologia , Ophiostomatales/classificação , Filogenia , Quercus/microbiologia , Alnus/parasitologia , Animais , Besouros/microbiologia , Código de Barras de DNA Taxonômico , Fagus/parasitologia , Hifas/classificação , Hifas/genética , Hifas/ultraestrutura , Noruega , Ophiostomatales/genética , Ophiostomatales/isolamento & purificação , Filogeografia , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Polônia , Quercus/parasitologia , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/ultraestrutura
18.
Food Microbiol ; 73: 264-274, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29526211

RESUMO

Alternaria leaf-spot is a new disease recently reported on basil in Italy. The correct identification of Alternaria species has suffered from many reclassifications in function of morphological features and molecular data. In our study, we performed an overall approach to obtain a better characterization of basil Alternaria isolates. Morphological characteristics, seven-genome region phylogenic analysis, and secondary metabolite profile differentiated the majority of the isolates as A. alternata. OPA 1-3 and OPA 10-2 were the best molecular regions to discriminate among the isolates. Morphological characteristics and sporulation groups helped to discriminate A. tenuissima from A. alternata isolates. All isolates in the A. sect. Alternaria were mycotoxigenic and pathogenic on basil, the production of mycotoxins was enhanced on basil compared to in vitro conditions used in this work.


Assuntos
Alternaria/classificação , Alternaria/genética , Ocimum basilicum/microbiologia , Doenças das Plantas/microbiologia , Alternaria/isolamento & purificação , Alternaria/metabolismo , Itália , Micotoxinas/análise , Micotoxinas/metabolismo , Filogenia , Metabolismo Secundário , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/isolamento & purificação
19.
Parasitol Res ; 117(9): 2823-2829, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29931393

RESUMO

A microsporidium was found in a Mediterranean cricket Gryllus bimaculatus from a pet market in the UK and a lab stock at the Moscow Zoo (originating from London Zoo). The spores were ovoid, uninucleate, 6.3 × 3.7 µm in size (unfixed), in packets by of 8, 16, or 32. The spores were easily discharged upon dessication or slight mechanical pressure. The polar tube was isofilar, with 15-16 coils arranged in 1-2 rows. The polaroplast was composed of thin lamellae and occupied about one third of the spore volume. The endospore was 200 nm thick, thinning over the anchoring disc. The exospore was thin, uniform, and with no ornamentation. Phylogenetics based upon small subunit ribosomal RNA (Genbank accession # MG663123) and RNA polymerase II largest subunit (# MG664544) genes placed the parasite at the base of the Trachipleistophora/Vavraia lineage. The RPB1 locus was polymorphic but similar genetic structure and identical clones were found in both isolates, confirming their common geographic origin. Due to in insufficient ultrastructural data and prominent divergence from described species, the parasite is provisionally placed to the collective taxon Microsporidium.


Assuntos
Gryllidae/microbiologia , Microsporídios não Classificados/classificação , Microsporídios não Classificados/genética , Esporos Fúngicos/classificação , Animais , Londres , Filogenia , RNA Polimerase II/genética , Subunidades Ribossômicas Menores de Eucariotos/genética
20.
Mycorrhiza ; 28(1): 49-58, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28942552

RESUMO

Chinese Douglas-fir (Pseudotsuga sinensis) is an endangered Pinaceae species found in several isolated regions of China. Although soil spore banks of ectomycorrhizal (ECM) fungi can play an important role in seedling establishment after disturbance, such as in the well-known North American relative (Pseudotsuga menziesii), we have no information about soil spore bank communities in relict forests of Chinese Douglas-fir. We conducted bioassays of 73 soil samples collected from three Chinese Douglas-fir forests, using North American Douglas-fir as bait seedlings, and identified 19 species of ECM fungi. The observed spore bank communities were significantly different from those found in ECM fungi on the roots of resident trees at the same sites (p = 0.02). The levels of potassium (K), nitrogen (N), organic matter, and the pH of soil were the dominant factors shaping spore bank community structure. A new Rhizopogon species was the most dominant species in the spore banks. Specifically, at a site on Sanqing Mountain, 22 of the 57 surviving bioassay seedlings (representing 21 of the 23 soil samples) were colonized by this species. ECM fungal richness significantly affected the growth of bioassay seedlings (R 2 = 0.20, p = 0.007). Growth was significantly improved in seedlings colonized by Rhizopogon or Meliniomyces species compared with uncolonized seedlings. Considering its specificity to Chinese Douglas-fir, predominance in the soil spore banks, and positive effect on host growth, this new Rhizopogon species could play critical roles in seedling establishment and forest regeneration of endangered Chinese Douglas-fir.


Assuntos
Ascomicetos/fisiologia , Basidiomycota/fisiologia , Micorrizas/fisiologia , Pseudotsuga/microbiologia , Microbiologia do Solo , Solo/química , Esporos Fúngicos/fisiologia , Ascomicetos/classificação , Basidiomycota/classificação , China , Espécies em Perigo de Extinção , Florestas , Micorrizas/classificação , Esporos Fúngicos/classificação
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