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1.
Front Microbiol ; 14: 1149853, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37125158

RESUMEN

Members from the genus Fusarium can infect a broad range of plants and threaten agricultural and horticultural production. Studies on the diversity of Fusarium occurring in natural ecosystems have received less attention than the better known phytopathogenic members of the genus. This study identified Fusarium species from soils with low anthropogenic disturbance found in the Golden Gate Highlands National Park (GGHNP), a part of the Drakensberg system in South Africa. Selective techniques were implemented to obtain 257 individual isolates from the selected soil samples for which the translation elongation factor 1α (tef-1α) gene region was sequenced and compared against the Fusarium MLST and FUSARIUM-ID databases. Phylogenetic analyses, based on maximum likelihood and Bayesian inference, were used to determine species diversity in relation to reference isolates. Species level identifications were made within three of the seven species complexes and identified F. brachygibbosum, F. sporotrichioides, F. andiyazi, and F. gaditjirri based on the FUSARIUM-ID database, with F. transvaalense and F. lyarnte identified against the Fusarium MLST database. This indicated highly diverse populations of Fusarium from soils with low anthropogenic disturbance from the Afromontane grassland region found in mountain ranges.

2.
Phytopathology ; 111(8): 1459-1469, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33225833

RESUMEN

The genetic diversity of pathogenic members of the Fusarium oxysporum species complex (FOSC) has been intensively studied worldwide, yet strains occurring in native soils with low anthropogenic disturbance remain poorly understood. This study focused on 355 F. oxysporum isolates from soils with low anthropogenic activity obtained from the grassland biome of South Africa. Analysis of the translation elongation factor 1-alpha (tef-1α) gene revealed high levels of sequence type diversity within the soil population in comparison with the global dataset. Phylogenetic relationships of the South African isolates revealed that four nested within FOSC clade 1. This is the first report of members of the basal clade recovered from ecosystems with low anthropogenic disturbance from Sub-Saharan Africa. The remaining strains nested within clades 2 to 5. This study contributes significantly to our understanding of the distribution of the FOSC in natural systems as we show that FOSC populations in the South African grassland biome are genetically diverse. This fills in our knowledge gap because previous studies reported only on the occurrence and diversity of the FOSC isolated from plant debris in South Africa. This is the first comprehensive survey of fusaria from grassland soils with low anthropogenic disturbance in South Africa.


Asunto(s)
Fusarium , Ecosistema , Fusarium/genética , Variación Genética , Pradera , Filogenia , Enfermedades de las Plantas , Sudáfrica
3.
MycoKeys ; 63: 1-48, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32089638

RESUMEN

Macrofungi are considered as organisms that form large fruiting bodies above or below the ground that are visible without the aid of a microscope. These fungi include most basidiomycetes and a small number of ascomycetes. Macrofungi have different ecological roles and uses, where some are edible, medicinal, poisonous, decomposers, saprotrophs, predators and pathogens, and they are often used for innovative biotechnological, medicinal and ecological applications. However, comprehensive checklists, and compilations on the diversity and distribution of mushrooms are lacking for South Africa, which makes regulation, conservation and inclusion in national biodiversity initiatives difficult. In this review, we compiled a checklist of macrofungi for the first time (excluding lichens). Data were compiled based on available literature in journals, books and fungorium records from the National Collection of Fungi. Even if the list is not complete due to numerous unreported species present in South Africa, it still represents an overview of the current knowledge of the macromycetes of South Africa. The list of names enables the assessment of gaps in collections and knowledge on the fungal biodiversity of South Africa, and downstream applications such as defining residency status of species. It provides a foundation for new names to be added in future towards developing a list that will be as complete as possible, and that can be used by a wide audience including scientists, authorities and the public.

4.
Antonie Van Leeuwenhoek ; 111(11): 1999-2008, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29777450

RESUMEN

The genus Fusarium hosts a large number of economically significant phytopathogens with a global distribution. Surprisingly, only a limited number of studies have tried to identify the natural distribution of members of this genus in undisturbed soils. Members of the Fusarium incarnatum-equiseti species complex (FIESC) are increasingly associated with plant disease, and human and animal health problems. Recently, an outbreak of kikuyu poisoning of cattle was attributed to the F. incarnatum-equiseti species complex. Thus, it is of importance to identify the natural distribution of members of the FIESC from the environment. The aim of this study was to use the phylogenetic signal within the TEF 1α gene region to characterise 54 F. incarnatum-equiseti isolates obtained from undisturbed soils from the grassland biome of South Africa. These isolates were further compared with members of the FIESC previously associated with kikuyu poisoning of cattle. The phylogenetic analysis indicated a high level of variation within this species complex. Several members were closely related to isolates implicated in the death of cattle from infected kikuyu grass.


Asunto(s)
Fusarium/genética , Fusarium/clasificación , Datos de Secuencia Molecular , Filogenia , Microbiología del Suelo , Sudáfrica
5.
MycoKeys ; (32): 65-90, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29681738

RESUMEN

Taxonomic and phylogenetic studies of Chlorophyllum were carried out on the basis of morphological differences and molecular phylogenetic analyses. Based on the phylogeny inferred from the internal transcribed spacer (ITS), the partial large subunit nuclear ribosomal DNA (nrLSU), the second largest subunit of RNA polymerase II (rpb2) and translation elongation factor 1-α (tef1) sequences, six well-supported clades and 17 phylogenetic species are recognised. Within this phylogenetic framework and considering the diagnostic morphological characters, two new species, C. africanum and C. palaeotropicum, are described. In addition, a new infrageneric classification of Chlorophyllum is proposed, in which the genus is divided into six sections. One new combination is also made. This study provides a robust basis for a more detailed investigation of diversity and biogeography of Chlorophyllum.

6.
Onderstepoort J Vet Res ; 81(1): e1-e8, 2014 11 20.
Artículo en Inglés | MEDLINE | ID: mdl-25686222

RESUMEN

Kikuyu poisoning occurs sporadically in South Africa. It is of major economic importance, as valuable dairy cows are often poisoned by it, and once affected, the mortality rate is high. Pennisetum clandestinum samples were collected during eight outbreaks of kikuyu poisoning in cattle in the Eastern Cape Province of South Africa from 2008 to 2010. The kikuyu grass samples were submitted specifically for the isolation and molecular identification of Fusarium species, as it was recently suggested that mycotoxins synthesised by Fusarium torulosum could be the cause of this intoxication. Ninety-four Fusarium isolates were retrieved from the grass samples, of which 72 were members of the Fusarium incarnatum/Fusarium equiseti species complex based on morphology and phylogenetic analyses of the translation elongation factor 1α sequence data. The South African isolates from kikuyu identified as members of the F. incarnatum/F. equiseti species complex grouped together in six separate clades. The other isolates were Fusarium culmorum (n = 3), Fusarium redolens (n = 4) and Fusarium oxysporum (n = 15). Although F. torulosum could not be isolated from P. clandestinum collected during kikuyu poisoning outbreaks in South Africa, the mycotoxicosis theory is still highly plausible.


Asunto(s)
Enfermedades de los Bovinos/inducido químicamente , Brotes de Enfermedades/veterinaria , Fusarium/aislamiento & purificación , Pennisetum/microbiología , Intoxicación por Plantas/veterinaria , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , ADN de Hongos/genética , ADN de Hongos/aislamiento & purificación , Enfermedades Transmitidas por los Alimentos , Fusarium/clasificación , Intoxicación por Plantas/epidemiología , Intoxicación por Plantas/microbiología , Intoxicación por Plantas/patología , Sudáfrica/epidemiología
7.
Fungal Biol ; 114(7): 515-27, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20943163

RESUMEN

Pineapple (Ananas comosus) is native to South America and widely planted as a fruit crop in the tropics and sub-tropics. This plant is susceptible to a number of fungal diseases of which the most severe is fusariosis. The disease is caused by Fusarium guttiforme and occurs only in South and Central America. The occurrence of a similar disease on pineapples in South Africa has prompted a re-evaluation of the Fusarium sp. associated with pineapple fruit rot. Phylogenetic relationships of isolates from pineapples collected in Brazil and South Africa were assessed based on sequence data for the translation elongation factor-1-α, histone H3 and ß-tubulin gene regions. Analyses showed that the South African isolates represent a species distinct from Brazilian isolates. The South African isolates are characterised by a concentration of aerial mycelium at the centres of the colonies, different to the Brazilian isolates that have an even distribution of aerial mycelium. Both phylogenetic and morphological data show that the disease on pineapple in South Africa is caused by a new Fusarium species described here as F. ananatum sp. nov.


Asunto(s)
Ananas/microbiología , Fusarium/clasificación , Gibberella/clasificación , Enfermedades de las Plantas/microbiología , Brasil , Frutas/microbiología , Proteínas Fúngicas/genética , Fusarium/genética , Fusarium/aislamiento & purificación , Gibberella/genética , Gibberella/aislamiento & purificación , Datos de Secuencia Molecular , Factor 1 de Elongación Peptídica/genética , Filogenia , Sudáfrica
8.
Med Mycol ; 46(6): 589-94, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19180752

RESUMEN

A 40-year-old white male had a two-year history of right sided upper back pain without dyspnea or coughing. His past history was significant for allergic rhinitis and asthma. Conservative outpatient management of the back pain including medications, rest and physical therapy were ineffective. CT scan of the chest revealed a mass in the lower lobe of the right lung. Bronchial biopsy and lavage revealed eosinophilic and neutrophilic inflammation without tissue invasion. A pure culture of Bipolaris australiensis was confirmed by DNA typing. Hematological, serological and radiological studies were not compatible with Allergic Bronchopulmonary Mycosis (ABPM), fungus ball, hypersensitivity pneumonitis or invasive fungal infection. However, the mucus plugging may have represented an atypical localized form of ABPM. Resolution of the endobronchial mucus impaction occurred after three bronchoscopies with vigorous suction, anti fungal therapy and prednisone.


Asunto(s)
Ascomicetos/crecimiento & desarrollo , Dolor de Espalda/microbiología , Bronquios/microbiología , Enfermedades Pulmonares Fúngicas/complicaciones , Enfermedades Pulmonares Fúngicas/microbiología , Moco/microbiología , Adulto , Ascomicetos/clasificación , Ascomicetos/genética , Ascomicetos/aislamiento & purificación , Dolor de Espalda/terapia , Humanos , Enfermedades Pulmonares Fúngicas/terapia , Masculino , Filogenia
9.
Mycologia ; 95(4): 637-45, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-21148973

RESUMEN

Phialocephala was established for species in the Leptographium complex that produce conidia from phialides at the apices of dark mononematous conidiophores. Some species previously included in Phialocephala were re-allocated to Sporendocladia because they resembled Thielaviopsis in having ring-wall-building conidial development and conidia with two attachment points that emerge in false chains. Despite this significant realignment of the genus, a great deal of morphological heterogeneity remains in Phialocephala. The objective of this study was to consider the heterogeneity among Phialocephala spp. based on comparisons of sequence data derived from the large and small subunits (LSU and SSU) of the rRNA operon of species in Phialocephala. Phialocephala dimorphospora, the type species of the genus, and P. fortinii grouped with genera of the Helotiales in phylogenetic trees generated based on the LSU and SSU datasets. Phialocephala xalapensis and P. fusca clearly are unrelated to Phialocephala sensu stricto and should represent a new genus in the Ophiostomatales. Phialocephala compacta resides with representatives of the Hypocreales, and we believe that it represents a distinct genus. Phialocephala scopiformis and P. repens are not closely related to the other Phialocephala species and group within the Dothideales. The morphological heterogeneity among species of Phialocephala clearly is reflected by phylogenetic analysis of sequence data from two conserved rRNA gene regions. Appropriate genera now need to be found to accommodate these fungi.

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