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1.
Neuroepidemiology ; : 1-9, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38952140

RESUMO

BACKGROUND: Smoking is a well-known risk factor for cardiovascular diseases, including myocardial infarction (MI) and ischemic stroke (IS). While the relationship between smoking and the risk of cardiovascular diseases is established, the impact of changing smoking habits post-IS on the risk of subsequent MI remains unclear. This study aims to elucidate the effects of alterations in smoking behavior following an IS diagnosis on the likelihood of experiencing an MI. METHODS: Utilizing data from the Korean National Health Insurance Services Database, this nationwide population-based cohort study included 199,051 participants diagnosed with IS between January 2010 and December 2016. Smoking status was categorized based on changes in smoking habits before and after IS diagnosis. The association between changes in smoking behavior and the risk of subsequent MI was analyzed using multivariable Cox proportional hazard regression models. RESULTS: During a median follow-up of 4.17 person-years, a total of 5,734 (2.88%) patients were diagnosed with MI after IS. Smoking quitters (2.93%) or former smokers (2.47%) have a similar or lower rate of MI than the average, even if they have smoked cigarettes, while sustained smokers (3.46%) or new smokers (3.81%) have much higher rates of MI. Among sustained and new smokers, the risk of incident MI was significantly higher than never smokers (new smoker adjusted HR [aHR]: 1.496, 95% CI: 1.262-1.774; sustained smoker aHR: 1.494, 95% CI: 1.361-1.641). Also, among the study participants, approximately two-thirds continued smoking after their IS diagnosis. CONCLUSION: Changing smoking habits after an IS diagnosis significantly influences the risk of subsequent MI. Specifically, continuing or starting to smoke after an IS diagnosis is associated with a higher risk of MI. These results underscore the importance of targeted smoking cessation interventions for stroke patients to reduce the risk of subsequent MI.

2.
BMC Public Health ; 24(1): 1241, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38711032

RESUMO

BACKGROUND: The impact of changes in physical activity after ischemic stroke (IS) on the subsequent myocardial infarction (MI) risk is not fully understood. We aimed to investigate the effects of changes in physical activity on the risk of MI after acute IS using data from the Korean National Health Insurance Services Database. METHODS: 224,764 patients newly diagnosed with IS between 2010 and 2016 who underwent two serial biannual health checkups were included. The participants were divided into four categories according to changes in their physical activity: persistent non-exercisers, new exercisers, exercise dropouts, and exercise maintainers. The primary outcome was a new diagnosis of incident MI. Multivariable Cox proportional models were used to assess the effects of changes in exercise habits on the risk of MI. RESULTS: After a median of 4.25 years of follow-up, 6,611 (2.94%) MI cases were observed. After adjusting for confounders, new exercisers and exercise maintainers were significantly associated with a lower risk of incident MI than persistent non-exercisers (aHR, 0.849; 95% CI, 0.792-0.911; P-value < 0.001; and aHR, 0.746; 95% CI, 0.696-0.801; P-value < 0.001, respectively). Effects were consistent across sexes, more pronounced in those > 65 years. Notably, any level of physical activity after stroke was associated with a reduced MI risk compared to no exercise. CONCLUSIONS: In this nationwide cohort study, commencing or sustaining physical activity after an IS corresponded to a diminished likelihood of subsequent MI development. Advocating physical activity in ambulatory stroke survivors could potentially attenuate the prospective risk of MI.


Assuntos
Exercício Físico , AVC Isquêmico , Infarto do Miocárdio , Humanos , Masculino , Feminino , Infarto do Miocárdio/epidemiologia , República da Coreia/epidemiologia , Pessoa de Meia-Idade , AVC Isquêmico/epidemiologia , Idoso , Incidência , Adulto , Fatores de Risco
3.
J Korean Med Sci ; 38(39): e334, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37821090

RESUMO

Heart failure (HF) is a chronic condition affecting millions of people worldwide. While the cardinal manifestations of HF are related to the cardiovascular system, it has become progressively evident that mild cognitive impairment (MCI) is also a significant complication of the disease. In fact, a significant number of patients with HF may experience MCI, which can manifest as deficits in attention, memory, executive function, and processing speed. The mechanisms responsible for cognitive dysfunction in HF are intricate and multifactorial. Possible factors contributing to this condition include decreased cerebral blood flow, thrombogenicity associated with HF, systemic inflammatory conditions, and proteotoxicity. MCI in HF has significant clinical implications, as it is linked to poorer quality of life, increased morbidity and mortality, and higher healthcare costs. Additionally, MCI can disrupt self-care behaviors, adherence to medication, and decision-making abilities, all of which are crucial for effectively managing HF. However, there is currently no gold standard diagnostic tool and follow-up strategy for MCI in HF patients. There is limited knowledge on the prevention and treatment of MCI. In conclusion, MCI is a common and clinically important complication of HF. Considering the substantial influence of MCI on patient outcomes, it is imperative for healthcare providers to be cognizant of this issue and integrate cognitive screening and management strategies into the care of HF patients.


Assuntos
Disfunção Cognitiva , Insuficiência Cardíaca , Humanos , Qualidade de Vida , Disfunção Cognitiva/complicações , Disfunção Cognitiva/diagnóstico , Atenção , Doença Crônica , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/terapia
4.
Antonie Van Leeuwenhoek ; 115(12): 1379-1392, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36239838

RESUMO

Plastic waste has a negative impact on marine ecosystems and the quantity of this source of anthropogenic pollution continues to increase. Several studies have investigated plastic biodegradation using various microorganisms. In this study, we isolated fungi from polyethylene terephthalate (PET) waste on Korean seacoasts and evaluated their ability to degrade plastic by comparing the diameters of the clear zones they formed on polycaprolactone (PCL) agar. We isolated 262 strains from 47 plastic waste sources and identified 108 fungal species via molecular methods. The PCL agar assay revealed that 87 species presented with varying degrees of PCL degradation capacity. Among them, certain fungal species were strong PCL degraders. The present study demonstrated the possibility that some fungi inhabiting plastic could potentially degrade it in the marine environment. We believe that the discoveries made herein lay theoretical and practical foundations for the development of novel bioremediation systems for marine plastispheres and help mitigate the environmental pollution issues related to plastic wastes.


Assuntos
Ecossistema , Plásticos , Ágar , Biodegradação Ambiental , Fungos/genética
5.
Antonie Van Leeuwenhoek ; 115(8): 1009-1029, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35678932

RESUMO

The genomes of two Penicillium strains were sequenced and studied in this study: strain 2HH was isolated from the digestive tract of Anobium punctatum beetle larva in 1979 and the cellulase hypersecretory strain S1M29, derived from strain 2HH by a long-term mutagenesis process. With these data, the strains were reclassified and insight is obtained on molecular features related to cellulase hyperproduction and the albino phenotype of the mutant. Both strains were previously identified as Penicillium echinulatum and this investigation indicated that these should be reclassified. Phylogenetic and phenotype data showed that these strains represent a new Penicillium species in series Oxalica, for which the name Penicillium ucsense is proposed here. Six additional strains (SFC101850, SFCP10873, SFCP10886, SFCP10931, SFCP10932 and SFCP10933) collected from the marine environment in the Republic of Korea were also classified as this species, indicating a worldwide distribution of this new taxon. Compared to the closely related strain Penicillium oxalicum 114-2, the composition of cell wall-associated proteins of P. ucsense 2HH shows five fewer chitinases, considerable differences in the number of proteins related to ß-D-glucan metabolism. The genomic comparison of 2HH and S1M29 highlighted single amino-acid substitutions in two major proteins (BGL2 and FlbA) that can be associated with the hyperproduction of cellulases. The study of melanin pathways shows that the S1M29 albino phenotype resulted from a single amino-acid substitution in the enzyme ALB1, a precursor of the 1,8-dihydroxynaphthalene (DHN)-melanin biosynthesis. Our study provides important knowledge towards understanding species distribution, molecular mechanisms, melanin production and cell wall biosynthesis of this new Penicillium species.


Assuntos
Celulase , Penicillium , Celulase/genética , Genômica , Melaninas/metabolismo , Penicillium/genética , Filogenia
6.
Liver Transpl ; 24(12): 1680-1689, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30240130

RESUMO

We aimed to evaluate the association between intraoperative pulmonary vascular resistance (PVR) and clinical outcome of liver transplantation (LT). Cardiovascular involvement of end-stage liver disease is relatively common, and hemodynamic instability during LT can be fatal to recipients. However, the clinical impact of intraoperative PVR in LT remains undetermined. A total of 363 adult recipients with intraoperative right heart catheterization from January 2011 to May 2016 were analyzed. Patients were divided into 2 groups according to PVR. Two separate analyses were performed according to the time point of measurement: at the beginning and at the end of LT. The primary outcome was all-cause death or graft failure during the follow-up period. Increased PVR was observed in 11.8% (43/363) of recipients at the beginning and 12.7% (46/363) of recipients at the end of LT. PVR at the beginning of LT had no significant effect on the rate of death or graft failure in the multivariate analysis (hazard ratio [HR], 1.24; 95% confidence interval [CI], 0.64-2.38; P = 0.52). In contrast, PVR at the end of LT was significantly associated with death or graft failure during the overall follow-up period (HR, 2.00; 95% CI, 1.13-3.54; P = 0.02). In conclusion, PVR at the end of LT, rather than the beginning, is associated with clinical outcome. Larger trials are needed to support this finding.


Assuntos
Doença Hepática Terminal/cirurgia , Rejeição de Enxerto/diagnóstico , Transplante de Fígado/efeitos adversos , Resistência Vascular , Cateterismo Cardíaco , Doença Hepática Terminal/mortalidade , Feminino , Seguimentos , Rejeição de Enxerto/epidemiologia , Sobrevivência de Enxerto , Humanos , Período Intraoperatório , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Fatores de Risco , Resultado do Tratamento
7.
Mycologia ; 107(1): 209-16, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25361832

RESUMO

Three strains of an unidentified Penicillium species were isolated during a fungal diversity survey of marine environments in Korea. These strains are described here as a new species following a multigene phylogenetic analyses of nuc rDNA internal transcribed spacer barcodes (ITS1-5.8S-ITS2), genes for ß-tubulin, calmodulin and RNA polymerase II second largest subunit, and observation of macro-and micromorphological characters. Phylogenetic analyses revealed that the three strains formed a strongly supported monophyletic group distinct from previously reported species of section Aspergilloides. Morphologically this species can be distinguished from its sister species, P. crocicola, by the reverse color on Czapek yeast autolysate agar, abundant production of sclerotia on malt extract agar and colony characters on yeast extract sucrose agar. We name this new species P. jejuense, after the locality where it was discovered. At 25 C for 7 d, P. jejuense colonies grew to 55-60 mm on CYA, 45-48 mm on MEA, 48-52 mm on YES and 23-26 mm on CREA. Conidia (2.2-3.4 × 2.0-2.6 µm) and sclerotia (160-340 × 125-210 µm) were globose to ellipsoidal.


Assuntos
Penicillium/classificação , Penicillium/isolamento & purificação , Água do Mar/microbiologia , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Dados de Sequência Molecular , Penicillium/genética , Penicillium/crescimento & desenvolvimento , Filogenia , República da Coreia , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/isolamento & purificação
8.
Opt Express ; 22(24): 30161-9, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25606946

RESUMO

We present experiments and analysis on enhanced transmission due to dielectric layer deposited on a metal film perforated with two-dimensional periodic array of subwavelength holes. The Si3N4 overlayer is applied on the perforated gold film (PGF) fabricated on GaAs substrate in order to boost the transmission of light at the surface plasmon polariton (SPP) resonance wavelengths in the mid- and long-wave IR regions, which is used as the antireflection (AR) coating layer between two dissimilar media (air and PGF/GaAs). It is experimentally shown that the transmission through the perforated gold film with 1.8 µm (2.0 µm) pitch at the first-order (second-order) SPP resonance wavelengths can be increased up to 83% (110%) by using a 750 nm (550 nm) thick Si3N4 layer. The SPP resonance leads to a dispersive resonant effective permeability (µeff ≠ 1) and thereby the refractive index matching condition for the conventional AR coating on the surface of a dielectric material cannot be applied to the resonant PGF structure. We develop and demonstrate the concept of AR condition based on the effective parameters of PGF. In addition, the maximum transmission (zero reflection) condition is analyzed numerically by using a three-layer model and a transfer matrix method is employed to determine the total reflection and transmission. The numerically calculated total reflection agrees very well with the reflection obtained by 3D full electromagnetic simulations of the entire structure. Destructive interference conditions for amplitude and phase to get zero reflection are well satisfied.


Assuntos
Luz , Ressonância de Plasmônio de Superfície , Impedância Elétrica , Ouro/química , Modelos Teóricos , Análise Numérica Assistida por Computador , Compostos de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier
9.
Antonie Van Leeuwenhoek ; 106(4): 593-603, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25052534

RESUMO

A new species, Trichoderma songyi, was found to be associated with the pine mushroom (Tricholoma matsutake) in Korea. This species was isolated from three different substrates: Tricholoma matsutake basidiomata, as well as roots of Pinus densiflora and soil in the fairy ring. Based on its molecular and phenotypic characteristics, we demonstrate that Trichoderma songyi is unique and distinguishable from closely related species. We performed phylogenetic analyses based on two molecular markers, the genes for both translation elongation factor 1-alpha and the second largest subunit of RNA polymerase II. Phylogenetic analyses showed that Trichoderma songyi is closely related to Trichoderma koningii aggregate and Trichoderma caerulescens. Morphologically, Trichoderma songyi can be distinguished from these closely related taxa by its growth rates, colony morphology on PDA in darkness, and coconut-like odour. Due to the economic importance of the pine mushroom, the relationship between Trichoderma songyi and Tricholoma matsutake should be studied further.


Assuntos
Pinus/microbiologia , Microbiologia do Solo , Trichoderma/classificação , Trichoderma/isolamento & purificação , Tricholoma , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , Coreia (Geográfico) , Dados de Sequência Molecular , Técnicas de Tipagem Micológica , Fator 1 de Elongação de Peptídeos/genética , Filogenia , RNA Polimerase II/genética , Análise de Sequência de DNA , Homologia de Sequência , Trichoderma/genética , Trichoderma/fisiologia
10.
Antonie Van Leeuwenhoek ; 106(2): 331-45, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24908060

RESUMO

The diversity of marine-derived Penicillium from Korea was investigated using morphological and multigene phylogenetic approaches, analyzing sequences of the internal transcribed spacer region, ß-tubulin gene, and RNA polymerase subunit II gene. In addition, the biological activity of all isolated strains was evaluated. We tested for the extracellular enzyme activity of alginase, endoglucanase, and ß-glucosidase, and antifungal activity against two plant pathogens (Colletotrichum acutatum and Fusarium oxysporum). A total of 184 strains of 36 Penicillium species were isolated, with 27 species being identified. The most common species were Penicillium polonicum (19.6 %), P. rubens (11.4 %), P. chrysogenum (11.4 %), and P. crustosum (10.9 %). The diversity of Penicillium strains isolated from soil (foreshore soil and sand) and marine macroorganisms was higher than the diversity of strains isolated from seawater. While many of the isolated strains showed alginase and ß-glucosidase activity, no endoglucanase activity was found. More than half the strains (50.5 %) showed antifungal activity against at least one of the plant pathogens tested. Compared with other strains in this study, P. citrinum (strain SFC20140101-M662) showed high antifungal activity against both plant pathogens. The results reported here expand our knowledge of marine-derived Penicillium diversity. The relatively high proportion of strains that showed antifungal and enzyme activity demonstrates that marine-derived Penicillium have great potential to be used in the production of natural bioactive products for pharmaceutical and/or industrial use.


Assuntos
Penicillium/classificação , Penicillium/isolamento & purificação , Antibiose , Organismos Aquáticos/classificação , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/enzimologia , Organismos Aquáticos/isolamento & purificação , Celulase/análise , Análise por Conglomerados , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Coreia (Geográfico) , Dados de Sequência Molecular , Penicillium/efeitos dos fármacos , Penicillium/enzimologia , Filogenia , Polissacarídeo-Liases/análise , RNA Polimerase II/genética , Análise de Sequência de DNA , Microbiologia do Solo , Tubulina (Proteína)/genética , beta-Glucosidase/análise
11.
Mycobiology ; 51(5): 288-299, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37929011

RESUMO

Aspergillus is one of the largest and diverse genera of fungi with huge economical, biotechnological, and social significance. Taxonomically, Aspergillus is divided into six subgenera comprising 27 sections. In this study, 235 strains of Aspergillus subgenus Circumdati (section: Candidi, Circumdati, Flavi, Flavipedes, Nigri, and Terrei) preserved at the Korean Agricultural Culture Collection (KACC) were analyzed and re-identified using a combined dataset of partial ß-tubulin (BenA), Calmodulin (CaM) gene sequences and morphological data. We confirmed nineteen species to be priorly reported in Korea (A. neotritici, A. terreus, A. floccosus, A. allahabadii, A. steynii, A. westerdijkiae, A. ochraceus, A. ostianus, A. sclerotiorum, A. luchuensis, A. tubingensis, A. niger, A. welwitschiae, A. japonicus, A. nomius, A. tamarii, A. parasiticus, A. flavi, and A. oryzae). Among the studied strains, three species (A. subalbidus, A. iizukae, and A. uvarum), previously unreported or not officially documented, were discovered in Korea, to the best of our knowledge. We have given a detailed description of the characteristic features of the three species, which remain uncharted in Korea.

12.
Sci Rep ; 13(1): 15481, 2023 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-37726368

RESUMO

Ticagrelor-based dual antiplatelet therapy (DAPT) provides potent antiplatelet inhibition but may increase the bleeding risk in Asian populations. We investigated the influence of early ticagrelor dose reduction (120 mg) on clinical outcomes in Korean patients undergoing percutaneous coronary intervention (PCI). A multicenter prospective clinical cohort study was conducted with patients who received standard-dose ticagrelor-based DAPT (180 mg) after PCI for complex lesions. Major adverse cardiovascular event (MACE: a composite of cardiovascular death, myocardial infarction, stroke, and repeat revascularization), bleeding, and net adverse clinical events (NACE: a composite of MACE and bleeding) were assessed. Among the 772 patients on standard-dose ticagrelor-based DAPT, 115 (14.8%) switched to low-dose ticagrelor-based DAPT (120 mg) within 6 months. Common reasons for the regimen changes were switching as planned (38.8%), dyspnea (25.5%), and bleeding (23.6%). A multivariable Cox proportional hazard model (CPH) showed that the risks of MACE, bleeding, and NACE were not different between the low-dose and standard-dose groups throughout the entire follow-up period and the period beyond 6 months post-PCI. Time-varying multivariable CPH models of the ticagrelor dose reduction yielded similar results. A reduction of the ticagrelor dose within 6 months after PCI is feasible and safe even in patients with complex lesions harboring a high ischemic event risk.


Assuntos
Intervenção Coronária Percutânea , Humanos , Ticagrelor , Intervenção Coronária Percutânea/efeitos adversos , Estudos de Coortes , Redução da Medicação , Inibidores da Agregação Plaquetária/efeitos adversos , Estudos Prospectivos
13.
J Korean Med Sci ; 27(12): 1598-600, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23255866

RESUMO

Selective intestinal decontamination (SID) with norfloxacin has been widely used for the prophylaxis of spontaneous bacterial peritonitis (SBP) because of a high recurrence rate and preventive effect of SID for SBP. However, it does select resistant gut flora and may lead to SBP caused by unusual pathogens such as quinolone-resistant gram-negative bacilli or gram-positive cocci. Enterococcus hirae is known to cause infections mainly in animals, but is rarely encountered in humans. We report the first case of SBP by E. hirae in a cirrhotic patient who have previously received an oral administration of norfloxacin against SBP caused by Klebsiella pneumoniae and presented in septic shock.


Assuntos
Enterococcus/isolamento & purificação , Infecções por Bactérias Gram-Positivas/microbiologia , Peritonite/diagnóstico , Sepse/etiologia , Administração Oral , Ampicilina/uso terapêutico , Antibacterianos/uso terapêutico , Líquido Ascítico/microbiologia , Infecções por Bactérias Gram-Positivas/complicações , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Peritonite/tratamento farmacológico , Peritonite/microbiologia
14.
Mycobiology ; 50(4): 231-237, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36158042

RESUMO

Penicillium species have been actively studied in various fields, and many new and unrecorded species continue to be reported in Korea. Moreover, unidentified and misidentified Korean Penicillium species still exist in GenBank. Therefore, it is necessary to revise the Korean Penicillium inventory based on accurate identification. We collected Korean Penicillium nucleotide sequence records from GenBank using the newly developed software, GenMine, and re-identified Korean Penicillium based on the maximum likelihood trees. A total of 1681 Korean Penicillium GenBank nucleotide sequence records were collected from GenBank. In these records, 1208 strains with four major genes (Internal Transcribed Spacer rDNA region, ß-tubulin, Calmodulin and RNA polymerase II) were selected for Penicillium re-identification. Among 1208 strains, 927 were identified, 82 were identified as other genera, the rest remained undetermined due to low phylogenetic resolution. Identified strains consisted of 206 Penicillium species, including 156 recorded species and 50 new species candidates. However, 37 species recorded in the national list of species in Korea were not found in GenBank. Further studies on the presence or absence of these species are required through literature investigation, additional sampling, and sequencing. Our study can be the basis for updating the Korean Penicillium inventory.

15.
Plant Pathol J ; 38(5): 461-471, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36221918

RESUMO

Erwinia amylovora is a causative pathogen of fire blight disease, affecting apple, pear, and other rosaceous plants. Currently, management of fire blight relies on cultural and chemical practices, whereas it has been known that few biological resources exhibit disease control efficacy against the fire blight. In the current study, we found that an SFC20201208-M01 fungal isolate exhibits antibacterial activity against E. amylovora TS3128, and the isolate was identified as a Penicillium brasilianum based on the ß-tubulin (BenA) gene sequence. To identify active compounds from the P. brasilianum culture, the culture filtrate was partitioned with ethyl acetate and n-butanol sequentially. From the ethyl acetate layer, we identified two new compounds (compounds 3-4) and two known compounds (compounds 1-2) based on spectroscopic analyses and comparison with literature data. Of these active compounds, penicillic acid (1) exhibited promising antibacterial activity against E. amylovora TS3128 with a minimal inhibitory concentration value of 25 µg/ml. When culture filtrate and penicillic acid (125 µg/ml) were applied onto Chinese pearleaf crab apple seedlings prior to inoculation of E. amylovora TS3128, the development of fire blight disease was effectively suppressed in the treated plants. Our results provide new insight into the biocontrol potential of P. brasilianum SFC20201208-M01 with an active ingredient to control fire blight.

16.
Environ Microbiol Rep ; 13(5): 649-658, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34162018

RESUMO

Fungi are key components of belowground ecosystems with various ecological roles in forests. Although the changes in the richness and composition of belowground fungi across altitudinal gradients have been widely reported, only a few studies have focused on the microhabitat types along altitudinal gradients. Here, we analysed the effect of altitude on the ectomycorrhizal and non-ectomycorrhizal fungal communities in belowground microhabitats. We collected root and soil samples from 16 Pinus densiflora forests at various altitudes across Korea, and measured the soil properties as potential factors. Fungal communities were analysed by high-throughput sequencing of the internal transcribed spacer 2 (ITS2) region. We found that altitude negatively affected the species richness of root-inhabiting fungi but did not influence that of soil-inhabiting fungi. In addition, the composition of ectomycorrhizal (ECM) fungi was less influenced by altitude than non-ECM fungi. Most of the soil properties did not show a significant relationship with altitude, but the effect of soil properties was different across microhabitat types and ecological roles of fungi. Our results reveal that microhabitat types and altitudinal gradients differently affect the richness and composition of fungal communities associated with P. densiflora, providing a better understanding of plant-associated fungal communities.


Assuntos
Micobioma , Micorrizas , Biodiversidade , Ecossistema , Micorrizas/genética , Microbiologia do Solo
17.
Mycobiology ; 49(4): 346-354, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34512078

RESUMO

The genus Aspergillus is commonly isolated from various marine and terrestrial environments; however, only a few species have been studied in rhizosphere soil. As part of the Korean indigenous fungal excavation project, we investigated fungal diversity from rhizosphere soil, focusing on Aspergillus species. A total of 13 strains were isolated from the rhizosphere soil of three different plants. Based on phylogenetic analysis of ß-tubulin and calmodulin and morphological characteristics, we identified five Aspergillus species. A. calidoustus and A. pseudodeflectus were commonly isolated from the rhizosphere soil. Four species were confirmed as unrecorded species in Korea: A. calidoustus, A. dimorphicus, A. germanicus, and A. pseudodeflecuts. The detailed morphological descriptions of these unrecorded species are provided.

18.
J Fungi (Basel) ; 7(6)2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34071658

RESUMO

In the search for antifungal agents from marine resources, we recently found that the culture filtrate of Trichoderma longibrachiatum SFC100166 effectively suppressed the development of tomato gray mold, rice blast, and tomato late blight. The culture filtrate was then successively extracted with ethyl acetate and n-butanol to identify the fungicidal metabolites. Consequently, a new compound, spirosorbicillinol D (1), and a new natural compound, 2',3'-dihydro-epoxysorbicillinol (2), together with 11 known compounds (3-13), were obtained from the solvent extracts. The chemical structures were determined by spectroscopic analyses and comparison with literature values. The results of the in vitro antifungal assay showed that of the tested fungal pathogens, Phytophthora infestans was the fungus most sensitive to the isolated compounds, with MIC values ranging from 6.3 to 400 µg/mL, except for trichotetronine (9) and trichodimerol (10). When tomato plants were treated with the representative compounds (4, 6, 7, and 11), bisvertinolone (6) strongly reduced the development of tomato late blight disease compared to the untreated control. Taken together, our results revealed that the culture filtrate of T. longibrachiatum SFC100166 and its metabolites could be useful sources for the development of new natural agents to control late blight caused by P. infestans.

19.
Front Microbiol ; 12: 804333, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35003037

RESUMO

Microbial metabolites have been recognized as an important source for the discovery of new antifungal agents because of their diverse chemical structures with novel modes of action. In the course of our screening for new antifungal agents from microbes, we found that culture filtrates of two fungal species Aspergillus candidus SFC20200425-M11 and Aspergillus montenegroi SFC20200425-M27 have the potentials to reduce the development of fungal plant diseases such as tomato late blight and wheat leaf rust. From these two Aspergillus spp., we isolated a total of seven active compounds, including two new compounds (4 and 6), and identified their chemical structures based on the NMR spectral analyses: sphaeropsidin A (1), (R)-formosusin A (2), (R)-variotin (3), candidusin (4), asperlin (5), montenegrol (6), and protulactone A (7). Based on the results of the in vitro bioassays of 11 plant pathogenic fungi and bacteria, sphaeropsidin A (1), (R)-formosusin A (2), (R)-variotin (3), and asperlin (5) exhibited a wide range of antimicrobial activity. Furthermore, when plants were treated with sphaeropsidin A (1) and (R)-formosusin A (2) at a concentration of 500 µg/ml, sphaeropsidin A (1) exhibited an efficacy disease control value of 96 and 90% compared to non-treated control against tomato late blight and wheat leaf rust, and (R)-formosusin A (2) strongly reduced the development of tomato gray mold by 82%. Asperlin (5) at a concentration of 500 µg/ml effectively controlled the development of tomato late blight and wheat leaf rust with a disease control value of 95%. Given that culture filtrates and active compounds derived from two Aspergillus spp. exhibited disease control efficacies, our results suggest that the Aspergillus-produced antifungal compounds could be useful for the development of new natural fungicides.

20.
Mycobiology ; 49(6): 551-558, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35035247

RESUMO

The Federated States of Micronesia (FSM) is an island country in the western Pacific and is a known biodiversity hotspot. However, a relatively small number of fungi (236 species) have been reported till July 2021. Since fungi play major ecological roles in ecosystems, we investigated the fungal diversity of FSM from various sources over 2016 and 2017 and constructed a local fungal inventory, which also included the previously reported species. Fruiting bodies were collected from various host trees and fungal strains were isolated from marine and terrestrial environments. A total of 99 species, of which 78 were newly reported in the FSM, were identified at the species level using a combination of molecular and morphological approaches. Many fungal species were specific to the environment, host, or source. Upon construction of the fungal inventory, 314 species were confirmed to reside in the FSM. This inventory will serve as an important basis for monitoring fungal diversity and identifying novel biological resources in FSM.

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