Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.027
Filtrar
1.
Mycoses ; 67(5): e13728, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38695201

RESUMO

BACKGROUND: Fungal keratitis is a severe eye infection that can result in blindness and visual impairment, particularly in developing countries. Fusarium spp. are the primary causative agents of this condition. Diagnosis of Fusarium keratitis (FK) is challenging, and delayed treatment can lead to serious complications. However, there is limited epidemiological data on FK, especially in tropical areas. OBJECTIVES: This study aimed to describe the clinical, laboratorial and epidemiological characteristics of FK in a tropical semi-arid region of Brazil. PATIENTS/METHODS: Adult patients with laboratory-confirmed FK diagnosed between October 2019 and March 2022 were evaluated. Fusarium isolates were characterized at molecular level and evaluated regarding antifungal susceptibility. RESULTS: A total of 226 clinical samples from patients suspected of keratitis were evaluated; fungal growth was detected in 50 samples (22.12%); out of which 42 were suggestive of Fusarium spp. (84%). Molecular analysis of a randomly selected set of 27 isolates identified F. solani species complex (n = 14); F. fujikuroi sensu lato (n = 6) and F. dimerum sensu lato (n = 7); a total of 10 haplotypes were identified among the strains. All but one Fusarium strains were inhibited by amphotericin B, natamycin and fluconazole. Most patients were male (71.42%; 30 out of 42), aged from 27 to 73 years old. Trauma was the most important risk factor for FK (40.47%; 17 out of 42). Patients were treated with antifungals, corticoids and antibiotics; keratoplasty and eye enucleation were also performed. CONCLUSIONS: The study provided insights into the characteristics of FK in tropical regions and emphasized the importance of enhanced surveillance and management strategies.


Assuntos
Antifúngicos , Infecções Oculares Fúngicas , Fusariose , Fusarium , Ceratite , Testes de Sensibilidade Microbiana , Humanos , Brasil/epidemiologia , Fusarium/genética , Fusarium/efeitos dos fármacos , Fusarium/isolamento & purificação , Fusarium/classificação , Masculino , Feminino , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Adulto , Ceratite/microbiologia , Ceratite/epidemiologia , Ceratite/tratamento farmacológico , Pessoa de Meia-Idade , Fusariose/microbiologia , Fusariose/epidemiologia , Fusariose/tratamento farmacológico , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/epidemiologia , Infecções Oculares Fúngicas/tratamento farmacológico , Idoso , Adulto Jovem , Adolescente , Clima Tropical , Idoso de 80 Anos ou mais , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico
2.
World J Microbiol Biotechnol ; 40(6): 185, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38683236

RESUMO

Stalk rot disease is a major constraint in maize production and till date reported to be caused by two to three species of phytopathogenic fungi but, in our present study, we disclose the first report of stalk rot is caused by complex species of phytopathogens, which belongs to five different genera. Therefore, to substantiate these findings, a total of 105 diseased samples of maize were collected from 21 different locations in six different geographical locations of India from which 48 isolates were used for the research study. Morphological features such as pigmentation, colony color, type of mycelium and pattern of mycelium was examined using macro and microscopic methods. A total of 11 different spp. of pathogens belonging to the five different genera: Fusarium verticillioides (56.25%), F. equiseti (14.5%), F. andiyazi (6.25%), F. solani (2.08%), F. proliferatum (2.08%), F. incarnatum (2.08%), Lasidioplodia theobrame (6.25%), Exserohilum rostrtum (4.16%), Nigrospora spp. (4.16%). and Schizophyllum commune (2.08%) were identified by different housekeeping genes (ITS, TEF-1α, RPB2 and Actin). Fusarium verticillioides, F. equiseti and F. andiyazi were major pathogens involved in stalk rot. This is the first report on F. proliferatum, F. solani, F. incarnatum, Lasidioplodia theobrame, Exserohilum rostrtum, Nigrospora spp. and Schizophyllum commune causing stalk rot of maize and their distribution in the different states of India. Studies on population dynamics of PFSR will enhance the understanding of pathogen behavior, virulence, or its association with different pathogens across India, which will facilitate the development of resistant maize genotypes against the PFSR.


Assuntos
Fusarium , Filogenia , Doenças das Plantas , Zea mays , Zea mays/microbiologia , Doenças das Plantas/microbiologia , Índia , Fusarium/genética , Fusarium/classificação , Fusarium/isolamento & purificação , Fusarium/patogenicidade , DNA Fúngico/genética , Fungos/genética , Fungos/classificação , Fungos/isolamento & purificação , Fungos/patogenicidade , Variação Genética
3.
World J Microbiol Biotechnol ; 40(6): 175, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38647735

RESUMO

The demand for environment-friendly cleanup techniques has arisen due to an increase in environmental pollutants. Fungi is the most prevalent and effective class of heavy metal-resistant microorganisms with the ability to leach metals. The objective of the present study was to isolate the fungi from the agricultural soil of Kashmir valley, investigate their multi-metal tolerance to heavy metals and evaluate the metal uptake capacities of the resistant fungi. The fungi were isolated and identified on the basis of morphological and molecular approach (ITS1 and ITS4). The tolerance limits of the isolated fungal strains to various doses of lead (Pb), cadmium (Cd), zinc (Zn), chromium (Cr), copper (Cu), nickel (Ni), and cobalt (Co) was evaluated. Five fungal strains, Aspergillus niger, Fusarium oxysporum, Fusarium verticillioides, Aspergillus fischeri, Epicoccum mackenziei were isolated from the soil samples. To the best of our knowledge, this is the first report on the study of metal resistance of Aspergillus fischeri and Epicoccum mackenziei. Among the identified fungal species, Aspergillus niger and Fusarium oxysporum were found to be most tolerant with a minimum inhibitory concentration (MIC) of 600 ppm against Cu and Cr respectively. Results indicated removal of considerable amount of heavy metals by some of the fungi. The highest metal uptake of 8.31 mg/g was found in Fusarium verticillioides for Zn. Surprisingly, these fungal strains demonstrated resistance to metal concentrations above the levels that are universally acceptable for polluted soils, and hence prove to be appealing contenders for use as bioremediation agents for cleaning up heavy metal-polluted environments.


Assuntos
Fungos , Fusarium , Metais Pesados , Testes de Sensibilidade Microbiana , Microbiologia do Solo , Poluentes do Solo , Metais Pesados/metabolismo , Poluentes do Solo/metabolismo , Fungos/efeitos dos fármacos , Fungos/isolamento & purificação , Fungos/classificação , Fungos/metabolismo , Fusarium/isolamento & purificação , Fusarium/efeitos dos fármacos , Fusarium/metabolismo , Biodegradação Ambiental , Aspergillus niger/isolamento & purificação , Aspergillus niger/efeitos dos fármacos , Aspergillus niger/metabolismo , Solo/química , Aspergillus/efeitos dos fármacos , Aspergillus/metabolismo , Aspergillus/isolamento & purificação
4.
Int J Food Microbiol ; 417: 110715, 2024 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-38657420

RESUMO

Head blight (HB) of oat (Avena sativa) has caused significant production losses in oats growing areas of western China. A total of 314 isolates, associated with HB were collected from the major oat cultivating areas of Gansu, Qinghai, and Yunnan Provinces in western China. Based on morphological characters, the isolates were initially classified into three genera, as differentiation to species was a bit difficult. Taxonomic analysis of these isolates based on muti-gene phylogenetic analyses (ITS, TEF1, TUB2, and RPB2) revealed four known Fusarium species, F. proliferatum, F. avenaceum, F. poae, and F. sibiricum, and one Acremonium specie (A. sclerotigenum). In addition, a new genus Neonalanthamala gen. nov., similar to genus Nalanthamala was introduced herein with a new combination, Neonalanthamala graminearum sp. nov., to accommodate the HB fungus. The molecular clock analyses estimated the divergence time of the Neonalanthamala and Nalanthamala based on a dataset (ITS, TUB2, RPB2), and we recognized the mean stem ages of the two genera are 98.95 Mya, which showed that they evolved from the same ancestor. N. graminearum was the most prevalent throughout the surveyed provinces. Pathogenicity test was carried out by using two different methods: seed inoculation and head inoculation. Results showed that F. sibiricum isolates were the most aggressive on the seed and head. A. sclerotigenum isolates were not pathogenic to seeds, and were developed less symptoms to the head compared to other species. Data analyses showed that the correlation of the germination potential, germination index, and dry weight of seed inoculation and disease index of plant inoculation had a highly significant negative correlation (P < 0.001). These results showed that the development of HB might be predicted by seed tests for this species. A. sclerotigenum and N. graminearum causing HB are being firstly reported on oat in the world. Similarly, F. proliferatum, F. avenaceum, F. poae and F. sibiricum causing oat HB are firstly reported in China.


Assuntos
Avena , Fusarium , Filogenia , Doenças das Plantas , Avena/microbiologia , Doenças das Plantas/microbiologia , China , Fusarium/genética , Fusarium/classificação , Fusarium/isolamento & purificação , Fusarium/patogenicidade , DNA Fúngico/genética , Acremonium/genética , Acremonium/classificação , Acremonium/isolamento & purificação
5.
Microb Pathog ; 190: 106594, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38458267

RESUMO

Fusarium wilt or Panama disease of banana caused by the hemibiotroph fungus, Fusarium odoratissimum, also known as F. oxysporum f.sp. cubense Tropical Race 4 is a serious threat to banana production worldwide. Being the world's largest grower and the origins of bananas in its northeast region, India is particularly vulnerable to this deadly fungus. In the present study, a total of 163 Fusarium isolates from infected banana were characterized for their pathogenic traits. Considering the variability in the Fusarium, the contaminated banana plants were collected from five districts of Uttar Pradesh and Bihar, two major primary infection states of India. All the isolates were screened using universal and specific primers to identify the F. odoratissimum strains. The identified F. odoratissimum strains were subjected to in vivo pathogenicity assessment using the susceptible banana cultivar 'Grand Naine'. The identified six most virulent strains were further characterized for their pathogenicity via in vivo bipartite interaction in terms of biochemical assays. Assessment of in vivo pathogenicity through qRT-PCR for three pathogenesis responsive genes, Six 1a (Secreted in xylem), Snf (Sucrose non-fermenting) and ChsV (Chitinase V), ascertained that the identified F. odoratissimum strains exhibit both intra- and inter-specific variability. The variability of F. odoratissimum strains signifies its importance for the assessment of spread of infection at specific sites to enable efficient management strategy of Fusarium wilt in banana.


Assuntos
Fusarium , Musa , Doenças das Plantas , Musa/microbiologia , Fusarium/genética , Fusarium/patogenicidade , Fusarium/isolamento & purificação , Fusarium/classificação , Doenças das Plantas/microbiologia , Índia , Virulência/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Filogenia
6.
N Engl J Med ; 390(6): 522-529, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38324485

RESUMO

A multinational outbreak of nosocomial fusarium meningitis occurred among immunocompetent patients who had undergone surgery with epidural anesthesia in Mexico. The pathogen involved had a high predilection for the brain stem and vertebrobasilar arterial system and was associated with high mortality from vessel injury. Effective treatment options remain limited; in vitro susceptibility testing of the organism suggested that it is resistant to all currently approved antifungal medications in the United States. To highlight the severe complications associated with fusarium infection acquired in this manner, we report data, clinical courses, and outcomes from 13 patients in the outbreak who presented with symptoms after a median delay of 39 days.


Assuntos
Surtos de Doenças , Fusariose , Fusarium , Doença Iatrogênica , Meningite Fúngica , Humanos , Antifúngicos/uso terapêutico , Fusariose/epidemiologia , Fusariose/etiologia , Fusarium/isolamento & purificação , Doença Iatrogênica/epidemiologia , Meningite Fúngica/epidemiologia , Meningite Fúngica/etiologia , México/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Internacionalidade , Imunocompetência , Farmacorresistência Fúngica , Analgesia Epidural/efeitos adversos
7.
Braz. j. biol ; 83: 1-7, 2023. ilus, tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1468917

RESUMO

Dengue fever vectored by the mosquito Aedes aegypti is one of the most rapidly spreading insect-borne diseases. Current reliance of dengue vector control is mostly on chemical insecticides. Growing insecticide resistance in the primary mosquito vector, Aedes aegypti, limits the effectiveness of vector control through chemical insecticides. These chemical insecticides also have negative environmental impacts on animals, plants and human health. Myco-biocontrol agents are naturally occurring organisms and are found to be less damaging to the environment as compared to chemical insecticides. In the present study, entomopathogenic potential of local strains of fungi isolated from soil was assessed for the control of dengue vector. Local fungal isolates presents better alternative to introducing a foreign biocontrol strain, as they may be better adapted to environmental conditions of the area to survive and may have more entomopathogenic efficacy against target organism. Larvicidal efficacy of Fusarium equiseti and Fusarium proliferatum was evaluated against Aedes aegypti. Local strains of F. equiseti (MK371718) and F. proliferatum (MK371715) were isolated from the soil of Changa Manga Forest, Pakistan by using insect bait method. Larvicidal activity of two Fusarium spp. was tested against forth instar larvae of A. aegypti in the laboratory, using concentrations 105, 106, 107 and 108 conidia /ml. LC50 values for F. equiseti after 24h, 48h, 72h and 96h of exposure were recorded as 3.8x108, 2.9x107, 2.0x107, and 7.1x106 conidia /ml respectively while LC50 values for F. proliferatum were recorded as 1.21x108, 9.6x107, 4.2x107, 2.6x107 conidia /ml respectively after 24h, 48h, 72h and 96h of exposure. The results indicate that among two fungal strains F. equiseti was found to be more effective in terms of its larvicidal activity than F. proliferatum against larvae of A. aegypti.


A dengue transmitida pelo mosquito Aedes aegypti é uma das doenças transmitidas por insetos de propagação mais rápida. A dependência atual do controle do vetor da dengue é principalmente de inseticidas químicos. O aumento da resistência a inseticidas no principal vetor do mosquito, Aedes aegypti, limita a eficácia do controle do vetor por meio de inseticidas químicos. Esses inseticidas químicos também têm impactos ambientais negativos sobre os animais, plantas e saúde humana. Os agentes de micobiocontrole são organismos que ocorrem naturalmente e são menos prejudiciais ao meio ambiente em comparação com os inseticidas químicos. No presente estudo, avaliou se o potencial entomopatogênico de cepas locais de fungos isolados do solo para o controle do vetor da dengue. Isolados de fungos locais apresentam melhor alternativa para a introdução de uma cepa de biocontrole estrangeira, pois podem ser mais bem adaptados às condições ambientais da área para sobreviver e podem ter maior eficácia entomopatogênica contra o organismo-alvo. A eficácia larvicida de Fusarium equiseti e Fusarium proliferatum foi avaliada contra Aedes aegypti. Cepas locais de F. equiseti (MK371718) e F. proliferatum (MK371715) foram isoladas do solo de Changa Manga Forest, Paquistão, usando o método de isca para insetos. Atividade larvicida de dois Fusarium spp. foi testado contra larvas de quarto ínstar de A. aegypti em laboratório, nas concentrações 105, 106, 107 e 108 conídios / ml. Os valores de LC50 para F. equiseti após 24 h, 48 h, 72 h e 96 h de exposição foram registrados como 3,8x 108, 2,9x107, 2,0x107 e 7,1x106 conídios / ml, respectivamente, enquanto os valores de LC50 para F. proliferatum foram registrados como 1,21x108, 9,6 x107, 4,2x107, 2,6x107 conídios / ml, respectivamente, após 24 h, 48 h, 72 h e 96 h de exposição. Os resultados indicam que entre duas cepas de fungos F. equiseti se mostrou mais eficaz em termos de atividade [...].


Assuntos
Animais , Aedes , Controle Biológico de Vetores/métodos , Fusarium/isolamento & purificação , Fusarium/patogenicidade
11.
Mar Drugs ; 20(2)2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-35200618

RESUMO

In many African countries, the Bayoud is a common disease spread involving the fungus Fusarium oxusporum f. sp. albedinis (Foa). The induction of plant natural defenses through the use of seaweed polysaccharides to help plants against pathogens is currently a biological and ecological approach that is gaining more and more importance. In the present study, we used alginate, a natural polysaccharide extracted from a brown algae Bifurcaria bifurcata, to activate date palm defenses, which involve phenylalanine ammonia-lyase (PAL), a key enzyme of phenylpropanoid metabolism. The results obtained showed that at low concentration (1 g·L-1), alginate stimulated PAL activity in date palm roots 5 times more compared to the negative control (water-treated) after 24 h following treatment and 2.5 times more compared to the laminarin used as a positive stimulator of plant natural defenses (positive control of induction). Using qRT-PCR, the expression of a selection of genes involved in three different levels of defense mechanisms known to be involved in response to biotic stresses were investigated. The results showed that, generally, the PAL gene tested and the genes encoding enzymes involved in early oxidative events (SOD and LOX) were overexpressed in the alginate-treated plants compared to their levels in the positive and negative controls. POD and PR protein genes selected encoding ß-(1,3)-glucanases and chitinases in this study did not show any significant difference between treatments; suggesting that other genes encoding POD and PR proteins that were not selected may be involved. After 17 weeks following the inoculation of the plants with the pathogen Foa, treatment with alginate reduced the mortality rate by up to 80% compared to the rate in control plants (non-elicited) and plants pretreated with laminarin, which agrees with the induction of defense gene expression and the stimulation of natural defenses in date palm with alginate after 24 h. These results open promising prospects for the use of alginate in agriculture as an inducer that triggers immunity of plants against telluric pathogens in general and of date palm against Fusarium oxysporum f. sp. albedinis in particular.


Assuntos
Alginatos/farmacologia , Phaeophyceae/química , Phoeniceae/microbiologia , Doenças das Plantas/prevenção & controle , Alginatos/isolamento & purificação , Fusariose/prevenção & controle , Fusarium/isolamento & purificação , Regulação da Expressão Gênica de Plantas/genética , Glucanos/farmacologia , Lipoxigenase/metabolismo , Phoeniceae/genética , Doenças das Plantas/microbiologia , Metabolismo Secundário , Superóxido Dismutase/metabolismo
12.
Toxins (Basel) ; 14(2)2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-35202130

RESUMO

Fusarium head blight (FHB) caused by fungi of the genus Fusarium is one of the most dangerous crop diseases, which has a wide geographic distribution and causes severe economic losses in the production of major cereal species. The infection leads to the accumulation of mycotoxins in grains, which compromises its suitability for human and animal consumption. The study demonstrated that grain samples from warmer regions of Poland, including Sulejów and Tomaszów Boleslawicki (results differed across years of the study), were colonized mainly by F. graminearum and were most highly contaminated with deoxynivalenol (DON). Samples from Northeastern Poland, i.e., Ruska Wies, which is located in a cooler region, were characterized by a predominance of Fusarium species typical of the cold climate, i.e., Fusarium poae and Penicillium verrucosum. A Spearman's rank correlation analysis revealed that the severity of grain infection with F. avenaceum/F. tricinctum was affected by the mean daily temperature and high humidity in May, and the corresponding values of the correlation coefficient were determined at R = 0.54 and R = 0.50. Competitive interactions were observed between the F. avenaceum/F. tricinctum genotype and DON-producing F. culmorum and F. graminearum, because the severity of grain infections caused by these pathogens was bound by a negative correlation.


Assuntos
Grão Comestível/química , Grão Comestível/microbiologia , Fusarium/isolamento & purificação , Tricotecenos/análise , Triticum/química , Triticum/microbiologia , Clima , DNA Fúngico/análise , Monitoramento Ambiental , Contaminação de Alimentos/análise , Fusarium/genética , Polônia
13.
Toxins (Basel) ; 14(1)2022 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-35051022

RESUMO

Fusarium head blight (FHB) is an economically important plant disease. Some Fusarium species produce mycotoxins that cause food safety concerns for both humans and animals. One especially important mycotoxin-producing fungus causing FHB is Fusarium graminearum. However, Fusarium species form a disease complex where different Fusarium species co-occur in the infected cereals. Effective management strategies for FHB are needed. Development of the management tools requires information about the diversity and abundance of the whole Fusarium community. Molecular quantification assays for detecting individual Fusarium species and subgroups exist, but a method for the detection and quantification of the whole Fusarium group is still lacking. In this study, a new TaqMan-based qPCR method (FusE) targeting the Fusarium-specific elongation factor region (EF1α) was developed for the detection and quantification of Fusarium spp. The FusE method was proven as a sensitive method with a detection limit of 1 pg of Fusarium DNA. Fusarium abundance results from oat samples correlated significantly with deoxynivalenol (DON) toxin content. In addition, the whole Fusarium community in Finnish oat samples was characterized with a new metabarcoding method. A shift from F. culmorum to F. graminearum in FHB-infected oats has been detected in Europe, and the results of this study confirm that. These new molecular methods can be applied in the assessment of the Fusarium community and mycotoxin risk in cereals. Knowledge gained from the Fusarium community analyses can be applied in developing and selecting effective management strategies for FHB.


Assuntos
Avena/microbiologia , Contaminação de Alimentos/análise , Microbiologia de Alimentos/métodos , Fusarium/isolamento & purificação , Micotoxinas/análise , Reação em Cadeia da Polimerase em Tempo Real/métodos , Código de Barras de DNA Taxonômico , Grão Comestível/microbiologia , Finlândia , Fusarium/classificação , Limite de Detecção , Micobioma
15.
Acta Ophthalmol ; 100(2): 159-163, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34031997

RESUMO

PURPOSE: To report an epidemiological update of documented fungal keratitis (FK) in a French tertiary ophthalmological centre from 2014 to 2018 in comparison with a previous period from 1993 to 2008. METHODS: Sixty-two consecutive FK documented by microbiological corneal scrapings were compared with the 64 FK of the previous study. Amphotericin B and voriconazole eye drops were administered hourly. Population characteristics, clinical findings, aetiological organisms and treatments were analysed. RESULTS: The most frequently identified fungi were Fusarium (61%), Aspergillus (6.5%) and Candida (5%). Thirty out of 44 cases examined with in vivo confocal microscopy (IVCM) presented filaments. Ten required conventional cross-linking, 9 therapeutic penetrating keratoplasty, and 2 enucleation. Risk factors significantly associated with the absence of response to medical treatment were patient age (p = 0.01), presence of a deep stromal infiltrate at presentation (p = 0.04) and high numbers of filaments in IVCM images (p = 0.01). The two populations were comparable in age, but not in sex ratio males/females (18/44 versus 37/26 in the previous study; p = 0.001). The frequency of contact lens-associated infection increased from 35.5% to 71% (p = 0.0001) between the two periods. Since then, filamentous FK increased from 69% (44/64) to 95% (59/62) (p = 0.0001). A history of keratoplasty was less frequently reported during the last period (3.2% (2/62) versus 17% (11/64) of cases (p = 0.01)). A clear decrease in the frequency of therapeutic keratoplasty was noted from 39% (25/64) to 14% (9/62) (p = 0.02). CONCLUSION: The frequency of filamentous keratomycosis is currently increasing. Elderly patients and the presence of numerous filaments in IVCM are associated with poor clinical outcomes.


Assuntos
Infecções Oculares Fúngicas/epidemiologia , Ceratite/epidemiologia , Adulto , Idoso , Aspergillus/isolamento & purificação , Candida/isolamento & purificação , Estudos de Casos e Controles , Infecções Oculares Fúngicas/diagnóstico , Infecções Oculares Fúngicas/microbiologia , Feminino , França/epidemiologia , Fusarium/isolamento & purificação , Humanos , Ceratite/diagnóstico , Ceratite/microbiologia , Masculino , Pessoa de Meia-Idade , Prevalência
16.
J Microbiol Methods ; 192: 106379, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34808145

RESUMO

This work addresses the mathematical model building to detect the diameter of the inhibition zone of gilaburu (Viburnum opulus L.) extract against eight different Fusarium strains isolated from diseased potato tubers. Gilaburu extracts were obtained with acetone, ethanol or methanol. The isolated Fusarium strains were: F. solani, F. oxysporum, F. sambucinum, F. graminearum, F. coeruleum, F. sulphureum, F. auneaceum and F. culmorum. In general, it was observed that ethanolic extracts showed highest antifungal activity. The antifungal activity of extracts was evaluated with machine learning (ML) methods. Several ML methods (classification and regression trees (CART), support vector machines (SVM), k-Nearest Neighbors (k-NN), artificial neural network (ANN), ensemble algorithms (EA), AdaBoost (AB) algorithm, gradient boosting (GBM) algorithm, random forests (RF) bagging algorithm and extra trees (ET)) were applied and compared for modeling fungal growth. From this research, it is clear that ML methods have the lowest error level. As a result, ML methods are reliable, fast, and cheap tools for predicting the antifungal activity of gilaburu extracts. These encouraging results will attract more research efforts to implement ML into the field of food microbiology instead of traditional methods.


Assuntos
Antifúngicos/farmacologia , Fusarium/crescimento & desenvolvimento , Aprendizado de Máquina , Extratos Vegetais/farmacologia , Solanum tuberosum/microbiologia , Viburnum/química , Algoritmos , Antioxidantes/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/métodos , Microbiologia de Alimentos , Fusarium/efeitos dos fármacos , Fusarium/isolamento & purificação
17.
Toxins (Basel) ; 13(12)2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34941693

RESUMO

The current study investigated the fungal diversity in freshly harvested oat samples from the two largest production regions in Brazil, Paraná (PR) and Rio Grande do Sul (RS), focusing primarily on the Fusarium genus and the presence of type B trichothecenes. The majority of the isolates belonged to the Fusarium sambucinum species complex, and were identified as F. graminearum sensu stricto (s.s.), F. meridionale, and F. poae. In the RS region, F. poae was the most frequent fungus, while F. graminearum s.s. was the most frequent in the PR region. The F. graminearum s.s. isolates were 15-ADON genotype, while F. meridionale and F. poae were NIV genotype. Mycotoxin analysis revealed that 92% and 100% of the samples from PR and RS were contaminated with type B trichothecenes, respectively. Oat grains from PR were predominantly contaminated with DON, whereas NIV was predominant in oats from RS. Twenty-four percent of the samples were contaminated with DON at levels higher than Brazilian regulations. Co-contamination of DON, its derivatives, and NIV was observed in 84% and 57.7% of the samples from PR and RS, respectively. The results provide new information on Fusarium contamination in Brazilian oats, highlighting the importance of further studies on mycotoxins.


Assuntos
Avena/química , Avena/microbiologia , Fusarium/isolamento & purificação , Tricotecenos do Tipo B/análise , Brasil , Grão Comestível/química , Grão Comestível/microbiologia , Contaminação de Alimentos/análise , Fusarium/classificação , Fusarium/genética , Micotoxinas/análise , Tricotecenos/análise
18.
Biomed Res Int ; 2021: 7913950, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34970627

RESUMO

Trichoderma spp. are widely distributed in natural habitats and have been evaluated as a potential biocontrol agent (BCA) for disease control and plant growth promotion. In this study, 1308 Trichoderma strains were obtained from the plant rhizosphere soil, above-ground plants, and decaying wood from natural habitats in China. Among them, 49 Trichoderma strains showed a good inhibitory effect, especially against Botrytis cinerea, Fusarium oxysporum, and Colletotrichum gloeosporioides with inhibition rate above 85% in the dual culture test. Among these 49 strains, the 13 strains with broad-spectrum inhibitory effects also significantly promoted the seed germination of five crops (rice, cucumber, tomato, melon, and pakchoi) and root growth of four crop seedlings (watermelon, tomato, eggplant, and chili). Furthermore, these strains showed effective colonization in the rhizosphere and root of cucumber. Trichoderma strains SC012 and NX043 showed the highest chitinase and ß-1,3-glucanase activity among all strains. Based on the morphological characterization and phylogenetic analysis of the nuclear ribosomal internal transcribed spacer (ITS) and translation elongation factor 1 (tef1), twelve Trichoderma strains were identified as Trichoderma asperellum and one as Trichoderma afroharzianum. This study suggests that the 13 Trichoderma strains are promising BCAs and could be developed as biofertilizers and biological pesticides for agricultural applications.


Assuntos
Hypocreales/classificação , Hypocreales/isolamento & purificação , Agricultura/métodos , Agentes de Controle Biológico/metabolismo , Botrytis/genética , Botrytis/isolamento & purificação , China , Produtos Agrícolas/microbiologia , Fusarium/genética , Fusarium/isolamento & purificação , Hypocreales/genética , Filogenia , Desenvolvimento Vegetal/genética , Doenças das Plantas/microbiologia , Microbiologia do Solo
19.
J Gen Virol ; 102(12)2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34850675

RESUMO

An extensive screening survey was conducted on Pakistani filamentous fungal isolates for the identification of viral infections. A total of 396 fungal samples were screened, of which 36 isolates were found double-stranded (ds) RNA positive with an overall frequency of 9% when analysed by a classical dsRNA isolation method. One of 36 dsRNA-positive strains, strain SP1 of a plant pathogenic fungus Fusarium mangiferae, was subjected to virome analysis. Next-generation sequencing and subsequent completion of the entire genome sequencing by a classical Sanger sequencing method showed the SP1 strain to be co-infected by 11 distinct viruses, at least seven of which should be described as new taxa at the species level according to the ICTV (International Committee on Taxonomy of Viruses) species demarcation criteria. The newly identified F. mangiferae viruses (FmVs) include two partitivirids, one betapartitivirus (FmPV1) and one gammapartitivirus (FmPV2); six mitovirids, three unuamitovirus (FmMV2, FmMV4, FmMV6), one duamitovirus (FmMV5), and two unclassified mitovirids (FmMV1, FmMV3); and three botourmiavirids, two magoulivirus (FmBOV1, FmBOV3) and one scleroulivirus (FmBOV2). The number of coinfecting viruses is among the largest ones of fungal coinfections. Their molecular features are thoroughly described here. This represents the first large virus survey in the Indian sub-continent.


Assuntos
Micovírus/genética , Fusarium/virologia , Micovírus/classificação , Micovírus/ultraestrutura , Fusarium/isolamento & purificação , Genoma Viral/genética , Paquistão , Filogenia , Doenças das Plantas/microbiologia , Plantas/microbiologia , Vírus de RNA/classificação , Vírus de RNA/genética , Vírus de RNA/ultraestrutura , RNA Viral/genética , Proteínas Virais/genética , Viroma/genética
20.
Pak J Biol Sci ; 24(10): 1015-1021, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34842370

RESUMO

<b>Background and Objective:</b> Endophytic fungi live in plant tissue and show no symptoms of disease in their host plants. It is known that endophytes as biological agents, can control plant diseases. In this study, isolated endophytic fungi from healthy Dayak Onion flowers were used as biocontrol agents in the control of the pathogenic fungi <i>Fusarium </i>spp. that causes molar disease in shallot plants. <b>Materials and Methods:</b> This study identifies the type of endophytic fungi molecularly isolated from Dayak onion flowers and determine the antagonistic effect of the endophytic extract against <i>Fusarium </i>spp. screening for endophytic fungi as antagonizing agents is carried out using the poisoned food method. <b>Results:</b> The results showed that two endophytic fungi isolates were obtained from healthy Dayak onion flowers, namely, EnI which was identified with the primers ITS1 and ITS4 as <i>Fusarium solani</i> and EnK as <i>Neoscytalidium </i>sp. <i>Fusarium</i> wilt caused by pathogenic fungi was identified as <i>Fusarium oxysporum</i>. The inhibitory percentage of EnI extract against the pathogenic fungus <i>Fusarium oxysporum</i> was 71.09% (high inhibition percentage) and the inhibition percentage of EnK was 38.54% (low inhibition percentage). <b>Conclusion:</b> Based on the results of this study, recommend using the endophytic fungus EnI extracts (<i>Fusarium solani </i>), extracted from Dayak onion flowers to control the pathogen <i>Fusarium oxysporum</i>.


Assuntos
Flores/microbiologia , Fusarium/isolamento & purificação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...