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1.
Carbohydr Polym ; 282: 119111, 2022 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-35123746

RESUMEN

Novel bio-based nanocomposites were developed as carriers for loading and sustained-release of vanillin (Van.) and cinnamaldehyde (Cinn.) antioxidants. The composites were obtained by intercalation of chitosan (CS) into sodium montmorillonite (CS/Mt), incorporation of chitosan with polyaniline (CS/PANI) and chitosan/polyaniline/exfoliated montmorillonite (CS/PANI/Mt). The structure and morphology of composites were characterized by FTIR, XRD, SEM and TEM. The release data of Van. and Cinn. from CS and CS/Mt obeyed well zero-order equation. However, Higuchi and Korsmeyer-Peppas models fitted well the release data from CS/PANI and CS/Mt composites. Their antifungal activity was examined towards Fusarium oxysporum and Pythium debaryanum. In vitro assay, CS, Cinn., Van., CS/PANI and CS/PANI/Cinn., have a strong inhibitory effect on the linear growth of the target pathogens, even at lower concentrations. Greenhouse assay indicated that seedling treatment by the loaded CS/PANI/Cinn and CS/Mt/Cinn. reduced both disease index and disease incidence parameters of both pathogens and possessed seedlings growth promoting potential of tomato compared to untreated-infected controls.


Asunto(s)
Acroleína/análogos & derivados , Antioxidantes/administración & dosificación , Benzaldehídos/administración & dosificación , Agentes de Control Biológico/administración & dosificación , Quitosano/administración & dosificación , Fusarium/efectos de los fármacos , Nanocompuestos/administración & dosificación , Enfermedades de las Plantas/prevención & control , Pythium/efectos de los fármacos , Solanum lycopersicum/microbiología , Acroleína/administración & dosificación , Acroleína/química , Adsorción , Compuestos de Anilina/administración & dosificación , Compuestos de Anilina/química , Antioxidantes/química , Bentonita/administración & dosificación , Bentonita/química , Benzaldehídos/química , Agentes de Control Biológico/química , Quitosano/química , Liberación de Fármacos , Fusarium/crecimiento & desarrollo , Solanum lycopersicum/crecimiento & desarrollo , Nanocompuestos/química , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/microbiología , Pythium/crecimiento & desarrollo
2.
Int J Mol Sci ; 22(24)2021 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-34948306

RESUMEN

Gliotoxin is a kind of epipolythiodioxopiperazine derived from different fungi that is characterized by a disulfide bridge. Gliotoxins can be biosynthesized by a gli gene cluster and regulated by a positive GliZ regulator. Gliotoxins show cytotoxic effects via the suppression the function of macrophage immune function, inflammation, antiangiogenesis, DNA damage by ROS production, peroxide damage by the inhibition of various enzymes, and apoptosis through different signal pathways. In the other hand, gliotoxins can also be beneficial with different doses. Low doses of gliotoxin can be used as an antioxidant, in the diagnosis and treatment of HIV, and as an anti-tumor agent in the future. Gliotoxins have also been used in the control of plant pathogens, including Pythium ultimum and Sclerotinia sclerotiorum. Thus, it is important to elucidate the toxic mechanism of gliotoxins. The toxic mechanism of gliotoxins and biosynthetic strategies to reduce the toxicity of gliotoxins and their producing strains are summarized in this review.


Asunto(s)
Gliotoxina/biosíntesis , Gliotoxina/toxicidad , Animales , Ascomicetos/efectos de los fármacos , Humanos , Familia de Multigenes/genética , Pythium/efectos de los fármacos
3.
Eur J Med Res ; 26(1): 132, 2021 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-34775999

RESUMEN

BACKGROUND: Pythium, soil-borne plant pathogens, are in the class Oomycetes. They are not true fungi, but are related to diatom and algae. There are two human pathogens including P. insidiosum and P. aphanidermatum. To date, only one case of pythiosis caused by P. aphanidermatum has been reported. We present herein the first case of P. aphanidermatum vascular pythiosis in Asia. CASE PRESENTATION: A 47-year-old Thai woman, living in North Thailand, with ß thalassemia/hemoglobin E presented with acute recurrent arterial insufficiency of both legs. Emergent embolectomy with clot removal was performed. The pathology of the clot exhibited noncaseous granulomatous inflammation with many fungal hyphal elements. PCR identified P. aphanidermatum with 100% identity. Final diagnosis is vascular pythiosis. Unfortunately, the patient eventually expired after treatment with itraconazole, terbinafine, azithromycin, and doxycycline. CONCLUSIONS: To date, only one case of pythiosis caused by P. aphanidermatum has been reported. We present herein the first case of P. aphanidermatum vascular pythiosis in Asia.


Asunto(s)
Antifúngicos/uso terapéutico , Pitiosis/diagnóstico , Pitiosis/tratamiento farmacológico , Pythium/efectos de los fármacos , Azitromicina/uso terapéutico , Resultado Fatal , Femenino , Interacciones Huésped-Patógeno/efectos de los fármacos , Humanos , Hifa/efectos de los fármacos , Hifa/fisiología , Itraconazol/uso terapéutico , Persona de Mediana Edad , Pitiosis/microbiología , Pythium/fisiología , Terbinafina/uso terapéutico , Tailandia , Trombosis/microbiología
4.
Microbiol Res ; 248: 126766, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33873139

RESUMEN

This work highlights the ability of various cyanobacterial extracts from Anabaena spp., Tolypothrix spp., Nostoc or Trichormus, among others genera, to control the incidence of damping-off caused by Pythium ultimum in cucumber seedlings. Protocols applied aimed at the preliminary characterization of the cyanobacterial collection were very useful for predicting their phytotoxic, phytostimulating and biopesticidal capacity. First, the phytostimulatory or phytotoxic potential of a collection of 31 sonicated cyanobacterial extracts was analyzed by calculating the germination index in watercress seeds and the increase or loss of seedling weight. Likewise, the collection was characterized according to its ability to inhibit the growth of P. ultimum by dual culture bioassays and detached-leaf test. Finally, after selecting the most effective extracts, a preventive damping-off bioassay was performed based on cucumber seed biopriming. The strain SAB-M465 showed to be the most efficient strain against the in vitro growth of P. ultimum, while SAB-B912 was more discreet in this regard, but proved to be the most effective as a germination stimulator. Seed biopriming strategy with sonicated extracts of cyanobacteria revealed a remarkable promoter effect in the early stages of plant development, although only SAB-M465 was positioned as an effective control agent against damping-off caused by P. ultimum in cucumber seedbeds.


Asunto(s)
Agentes de Control Biológico/farmacología , Cucumis sativus/microbiología , Cianobacterias/química , Enfermedades de las Plantas/prevención & control , Pythium/efectos de los fármacos , Semillas/crecimiento & desarrollo , Agentes de Control Biológico/aislamiento & purificación , Cucumis sativus/crecimiento & desarrollo , Germinación/efectos de los fármacos , Enfermedades de las Plantas/microbiología , Pythium/crecimiento & desarrollo , Plantones/crecimiento & desarrollo , Plantones/microbiología , Semillas/microbiología , Sonicación
5.
Molecules ; 26(4)2021 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-33671833

RESUMEN

Our present study was designed to investigate the role of both Trichoderma harzianum and chamomile (Matricaria chamomilla L.) flower extract in mutual reaction against growth of Pythium ultimum. In vitro, the activity of chamomile extract was found to reduce the radial growth of Pythium ultimum up to 30% compared to the control. Whereas, the radial growth reduction effect of T. harzianum against P. ultimum reached 81.6% after 120 h. Data also showed the productivity of total phenolics and total flavonoids by T. harzianum, was 12.18 and 6.33 mg QE/100 mL culture filtrate, respectively. However, these compounds were determined in chamomile flower extract at concentrations of 75.33 and 24.29 mg QE/100 mL, respectively. The fractionation of aqueous extract of chamomile flower using HPLC provided several polyphenolic compounds such as pyrogallol, myricetin, rosemarinic acid, catechol, p-coumaric acid, benzoic acid, chlorogenic acid and other minor compounds. In vivo, the potentiality of T. harzianum with chamomile flower extract against Pythium pathogen of bean was investigated. Data obtained showed a reduction in the percentage of rotted seed and infected seedling up to 28 and 8%, respectively. Whereas, the survival increased up to 64% compared to other ones. There was also a significant promotion in growth features, total chlorophyll, carotenoids, total polyphenols and flavonoids, polyphenol-oxidase and peroxidase enzymes compared to other ones. To the best of our knowledge, there are no reported studies that included the mutual association of fungus, T. harzianum with the extract taken from the chamomile flower against P. ultimum, either in vitro or in vivo. In conclusion, the application of both T. harzianum and/or M. chamomilla extracts in the control of bean Pythium pathogen showed significant results.


Asunto(s)
Manzanilla/química , Flavonoides/farmacología , Flores/química , Hypocreales/química , Fenoles/farmacología , Extractos Vegetales/farmacología , Pythium/efectos de los fármacos , Flavonoides/química , Flavonoides/aislamiento & purificación , Hypocreales/metabolismo , Fenoles/química , Fenoles/aislamiento & purificación , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Pythium/crecimiento & desarrollo , Pythium/patogenicidad
6.
Med Mycol ; 59(1): 67-73, 2021 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-32400872

RESUMEN

Pythium insidiosum infections have been widely studied in an attempt to develop an effective therapeutic protocol for the treatment of human and animal pythiosis. Several antifungal agents are still prescribed against this oomycete, although they present contradictory results. To evaluate the susceptibility profile and to verify the morphological alterations in P. insidiosum isolates treated with amorolfine hydrochloride and azithromycin, alone or in combination. Susceptibility tests for P. insidiosum isolates (n = 20) against amorolfine hydrochloride (AMR) and azithromycin (AZM) were performed according to Clinical and Laboratory Standards Institutes (CLSI) protocol M38-A2. Combinations of both drugs were evaluated using the checkerboard microdilution method. Additionally, transmission and scanning electron microscopy were performed in order to verify the morphological alterations in P. insidiosum isolates in response to these drugs. All P. insidiosum isolates had a minimum inhibitory concentration (MIC) ranging from 16 to 64 mg/l and 8 to 64 mg/l for amorolfine hydrochloride and azithromycin, respectively. Synergistic interactions between the drugs were not observed, with antagonism in 59.8% of isolates, and indifferent interactions in 36.2%. Electron microscopy showed changes in the surface of P. insidiosum hyphae, disorganization of intracellular organelles, and changes in the plasma membrane and cell wall of oomycetes treated with the drugs. This is the first study to demonstrate in vitro anti-P. insidiosum effect of amorolfine hydrochloride. These results indicate the therapeutic potential of this drug against cutaneous and subcutaneous forms of pythiosis, but further studies are necessary to confirm this potential.


Asunto(s)
Antifúngicos/farmacología , Azitromicina/farmacología , Pruebas de Sensibilidad Microbiana/veterinaria , Morfolinas/farmacología , Pitiosis/tratamiento farmacológico , Pythium/efectos de los fármacos , Animales , Antifúngicos/uso terapéutico , Azitromicina/uso terapéutico , Modelos Animales de Enfermedad , Perros , Caballos , Humanos , Morfolinas/uso terapéutico
7.
Mol Divers ; 25(1): 205-221, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32056130

RESUMEN

Based on the strategy of diversity-oriented synthesis and the structures of natural product pimprinine and streptochlorin, two series of novel pimprinine derivatives containing 1,3,4-oxadiazole-5-thioether moieties were efficiently synthesized under the optimized reaction conditions. Biological assays conducted at Syngenta showed the designed derivatives displayed an altered pattern of biological activity, of which 5h was identified as the most promising compound with strong activity against Pythium dissimile and also a broad antifungal spectrum in primary screening. Further structural optimization of pimprinine and streptochlorin derivatives is well under way, aiming to discover synthetic analogues with improved antifungal activity. Two series of novel pimprinine derivatives containing 1,3,4-oxadiazole-5-thioether moieties were efficiently synthesized through diversity-oriented synthesis strategy under the optimized conditions. Biological assays showed the designed derivatives exhibited potential activity.


Asunto(s)
Antifúngicos/síntesis química , Oxadiazoles/química , Oxazoles/química , Sulfuros/química , Antifúngicos/química , Antifúngicos/farmacología , Productos Biológicos/química , Productos Biológicos/farmacología , Indoles/química , Pruebas de Sensibilidad Microbiana/métodos , Pythium/efectos de los fármacos , Relación Estructura-Actividad
8.
Nat Prod Res ; 35(17): 2823-2830, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31578086

RESUMEN

Two new compounds, dalpulanone (1) and 2-hydroxyisomucronustyrene (2), were isolated from the stems of Dalbergia stipulacea. Fourteen known compounds (3-16) were also isolated. The chemical structures of all isolated compounds were elucidated using spectroscopic methods, including 1D-NMR, 2D-NMR, MS and IR data. Compound 4 displayed the strongest antifungal activity against Pythium insidiosum and had higher activity than the amphotericin-B standard.


Asunto(s)
Antifúngicos/farmacología , Dalbergia , Pythium , Antifúngicos/aislamiento & purificación , Dalbergia/química , Espectroscopía de Resonancia Magnética , Estructura Molecular , Fitoquímicos/aislamiento & purificación , Fitoquímicos/farmacología , Tallos de la Planta/química , Pythium/efectos de los fármacos
9.
World J Microbiol Biotechnol ; 36(5): 77, 2020 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-32399738

RESUMEN

Protease mediated proteolysis has been widely implicated in virulence of necrotrophic fungal pathogens. This is counteracted in plants by evolving new and effective antimicrobial peptides (AMP) that constitute important components of innate immune system. Peptide extraction from rhizome of Zingiber zerumbet was optimized using ammonium sulphate (50-80% w/v) and acetone (60 and 100% v/v) with maximal protein recovery of 1.2 ± 0.4 mg/g obtained using 100% acetone. Evaluation of inhibitory potential of Z. zerumbet rhizome protein extract to prominent hydrolases of necrotrophic Pythium myriotylum revealed maximal inhibition of proteases (75.8%) compared to other hydrolytic enzymes. Protein was purified by Sephacryl S200HR resin resulting in twofold purification and protease inhibition of 84.4%. Non-reducing polyacrylamide gel electrophoresis (PAGE) of the fractions yielded two bands of 75 kDa and 25 kDa molecular size. Peptide mass fingerprint of the protein bands using matrix assisted laser desorption/ionization (MALDI)-time of flight (TOF) mass spectroscopy (MS) and subsequent MASCOT searches revealed peptide match to methylesterase from Arabidopsis thaliana (15%) and to hypothetical protein from Oryza sativa (98%) respectively. Further centrifugal filter purification using Amicon Ultra (10,000 MW cut-off) filter, yielded a prominent band of 25 kDa size. Concentration dependent inhibition of zoospore viability by Z. zerumbet AMP designated as ZzAMP was observed with maximal inhibition of 89.5% at 4 µg protein and an IC50 value of 0.59 µg. Studies are of particular relevance in the context of identifying the molecules involved in imparting below ground defense in Z. zerumbet as well in development of AMPs as potential candidate molecules for control of necrotrophic pathogens of agricultural relevance.


Asunto(s)
Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Péptido Hidrolasas/efectos de los fármacos , Extractos Vegetales/farmacología , Pythium/efectos de los fármacos , Rizoma/microbiología , Zingiberaceae/microbiología , Antibacterianos/química , Péptidos Catiónicos Antimicrobianos/química , Arabidopsis , Inhibidores Enzimáticos , Hongos/efectos de los fármacos , Oryza , Péptidos/farmacología , Extractos Vegetales/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Zingiberaceae/crecimiento & desarrollo
10.
Vet Microbiol ; 243: 108616, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32273002

RESUMEN

This study examined the effect of minocycline alone and in combination with immunotherapy against pythiosis. Twenty rabbits, aged three months old and subcutaneously inoculated with Pythium insidiosum zoospores were divided into four groups (n = 5): treated with minocycline (10 mg/kg/day twice daily), treated with immunotherapy (34 mg subcutaneously every 14 days), treated with minocycline plus immunotherapy, and untreated (control group). The treatments were started 30 days after inoculation and continued for 70 days. The subcutaneous nodular injury areas in infected groups were measured every seven days after the beginning of treatment. Only the rabbits that developed lesions were selected for this study. When compared with the control group over 70 days, the minocycline and minocycline plus immunotherapy groups of rabbits with pythiosis showed significantly reduced injuries. The histopathology showed the presence of inflammation, macrophages and eosinophils. Grocott's staining revealed irregular hyphae-like structures that were ramified and occasionally septate. Our results suggest that minocycline has fungistatic activity and that the combination of minocycline and immunotherapy is more effective than the individual therapies tested.


Asunto(s)
Inmunoterapia , Minociclina/uso terapéutico , Pitiosis/tratamiento farmacológico , Pitiosis/terapia , Pythium/efectos de los fármacos , Animales , Inyecciones Subcutáneas , Pitiosis/inmunología , Conejos
11.
Sci Rep ; 10(1): 4495, 2020 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-32161276

RESUMEN

Pythiosis is a harmful disease caused by Pythium insidiosum, an aquatic oomycete. Therapeutic protocols based on antifungal drugs are often ineffective because the cytoplasmic membrane of P. insidiosum does not contain ergosterol. Therefore, the treatment of pythiosis is still challenging, particularly making use of natural products and secondary metabolites from bacteria. In this study, xanthyletin and substances obtained from Pseudomonas stutzeri ST1302 and Klebsiella pneumoniae ST2501 exhibited anti-P. insidiosum activity and, moreover, xanthyletin was non-toxic against human cell lines. The hyphae of P. insidiosum treated with these three substances exhibited lysis holes on a rough surface and release of anamorphic material. Therefore, xanthyletin could be considered a promising alternative agent for treating cutaneous pythiosis in the near future.


Asunto(s)
Antifúngicos/farmacología , Antiparasitarios/farmacología , Cumarinas/farmacología , Pythium/efectos de los fármacos , Bacterias/química , Bacterias/metabolismo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Mezclas Complejas , Fibroblastos/efectos de los fármacos , Humanos , Hifa/efectos de los fármacos , Hifa/ultraestructura , Pruebas de Sensibilidad Microbiana
12.
Med Mycol ; 58(7): 913-918, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-32030424

RESUMEN

Pythiosis is a rapidly progressing disease that can be lethal to affected individuals due to resistance to available therapeutic protocols. The disease affects mammals, with the largest number of reports in horses and humans. The present study investigated the activity of biogenic silver nanoparticles (bioAgNP) in the treatment of experimental pythiosis. The disease was reproduced in nine female 90-day-old New Zealand rabbits. Animals were divided into three groups: group1 (control, n = 3) daily and topically treated with a nonionized gel-based formulation and 1 ml of sterile distilled water intralesion administered every 48 hours; group 2 (n = 3), daily and topically treated with gel-based formulation containing 1 µg/ml bio-AgNP; group 3 (n = 3), treated with 1 ml bio-AgNP in 1 µg/ml aqueous solution intralesion administered every 48 hours. Animals were treated for 45 days, and the area of subcutaneous lesions was measured every 5 days. Results showed that groups 2 and 3 differed from control group (P < .05) in the lesion area, as well as the amount of hyphae within the lesions. It was observed that lesions of treated animals (groups 2 and 3) did not differ from each other, showing that the application route did not influence the regression of lesions. However, it was observed that one animal from group 2 reached clinical cure at 35 days of treatment. This research is pioneer in the application of nanocomposites for the treatment of experimental pythiosis and showed that bio-AgNP can be powerful allies of integrative medicine and can be included in pythiosis therapeutic protocols.


Asunto(s)
Nanopartículas del Metal/uso terapéutico , Pitiosis/tratamiento farmacológico , Pythium/efectos de los fármacos , Plata/uso terapéutico , Animales , Humanos , Conejos
13.
Curr Microbiol ; 77(6): 1006-1015, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32002625

RESUMEN

Heat-stable antifungal factor (HSAF) is a broad-spectrum antifungal antibiotic produced by the biological control agent, Lysobacter enzymogenes. In our earlier works, we have applied HSAF to effectively control wheat and pear fungal disease. However, a major bottleneck in its practical application is the low HSAF production level; therefore, boosting its production is essential for its wide application. In the past, we find that c-di-GMP, a universal bacterial second messenger, is inhibitory to HSAF production. In this work, we further identified eight active diguanylate cyclases (DGCs) responsible for c-di-GMP synthesis in Lysobacter enzymogenes via both bioinformatics and genetic analyses. We generated a strain lacking seven active DGC genes and found that this DGC-modified strain, OH11LC, produced a higher HSAF amount in a c-di-GMP concentration-dependent manner. Subsequently, by employing OH11LC as the host fermentation strain, we could even produce a much higher HSAF amount (> 200-fold). After improving the HSAF production, we further developed a technique of seed coating method with HSAF, which turned out to be effective in fighting against the maize seed-borne filamentous pathogen, Pythium gramineacola. Overall, via combining strain modification and fermentation optimization, we demonstrated a good example of translating fundamental knowledge of bacterial c-di-GMP signaling into biological control application in which we relieved the inhibitory effect of c-di-GMP on HSAF biosynthesis by deleting a bunch of potentially active L. enzymogenes DGC genes to improve HSAF yield and to expand its usage in antifungal seed coating.


Asunto(s)
Antifúngicos/metabolismo , Antifúngicos/farmacología , Proteínas de Escherichia coli/genética , Lysobacter/metabolismo , Liasas de Fósforo-Oxígeno/genética , GMP Cíclico/análogos & derivados , GMP Cíclico/metabolismo , Proteínas de Escherichia coli/metabolismo , Fermentación , Técnicas de Inactivación de Genes , Lysobacter/genética , Liasas de Fósforo-Oxígeno/metabolismo , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Pythium/efectos de los fármacos , Semillas/microbiología , Zea mays/microbiología
14.
Artículo en Inglés | MEDLINE | ID: mdl-32015039

RESUMEN

Human pythiosis is a life-threatening human disease caused by Pythium insidiosum In Thailand, vascular pythiosis is the most common form and carries a mortality rate of 10 to 40%, despite aggressive treatment with radical surgery, antifungal agents, and immunotherapy. Itraconazole and terbinafine have been the mainstay of treatment, until recently, based on case report data showing potential synergistic effects against Brazilian P. insidiosum isolates. However, the synergistic effects of itraconazole and terbinafine against Thai P. insidiosum isolates were not observed. This study tested the in vitro susceptibilities of 27 Thai human P. insidiosum isolates (clade II, n = 17; clade IV, n = 10), 12 Thai environmental P. insidiosum isolates (clade II, n = 4; clade IV, n = 8), and 11 non-Thai animal P. insidiosum isolates (clade I, n = 9; clade II, n = 2) to antibiotics in eight antibacterial classes to evaluate alternative effective treatments. Tetracycline and macrolide antibiotics demonstrated in vitro activity against Thai P. insidiosum isolates, with doxycycline MICs (1 to 16 µg/ml), minocycline MICs (1 to 4 µg/ml), tigecycline MICs (1 to 4 µg/ml), azithromycin MICs (1 to 16 µg/ml), and clarithromycin MICs (0.125 to 8 µg/ml) being the lowest, on average. Synergistic effects of tetracyclines and macrolides were also observed.


Asunto(s)
Antibacterianos/uso terapéutico , Antifúngicos/uso terapéutico , Antiparasitarios/uso terapéutico , Pitiosis/tratamiento farmacológico , Pythium/efectos de los fármacos , Azitromicina/uso terapéutico , Claritromicina/uso terapéutico , Doxiciclina/uso terapéutico , Humanos , Itraconazol/uso terapéutico , Macrólidos/uso terapéutico , Pruebas de Sensibilidad Parasitaria , Pythium/aislamiento & purificación , Terbinafina/uso terapéutico , Tetraciclinas/uso terapéutico , Tailandia
15.
Microbiol Res ; 230: 126347, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31586859

RESUMEN

Biocontrol has emerged in recent years as an alternative to pesticides. Given the importance of environmental preservation using biocontrol, in this study two antagonistic bacteria against phytopathogenic fungi were isolated and evaluated. These bacterial strains, identified as Paenibacillus polymyxa NMA1017 and Burkholderia cenocepacia CACua-24, inhibited (70 to 80%) the development of two phytopathogens of economic importance: the fungus Rhizoctonia solani RhCh-14, isolated from chili pepper, and the oomycete Pythium ultimum PyFr-14, isolated from tomato. The spectrum was not limited to the previous pathogens, but also to other phytopathogenic fungus, some bacteria and other oomycetes. Fungi-bacteria microcultures observed with optical and scanning electron microscopy revealed hyphae disintegration and pores formation. The antifungal activity was found also in the supernatant, suggesting a diffusible compound is present. Innocuous tests on tobacco leaves, blood agar, bean seed germination and in Galleria mellonella larvae showed that strain NMA1017 has the potential to be a biocontrol agent. Greenhouse experiments with bean plants inoculated with P. polymyxa exhibited the efficacy to inhibit the growth of R. solani and P. ultimum. Furthermore, P. polymyxa NMA1017 showed plant growth promotion activities, such as siderophore synthesis and nitrogen fixation which can contribute to the crop development.


Asunto(s)
Antifúngicos/farmacología , Burkholderia cenocepacia/química , Paenibacillus polymyxa/química , Control Biológico de Vectores/métodos , Enfermedades de las Plantas/microbiología , Pythium/efectos de los fármacos , Rhizoctonia/efectos de los fármacos , Antifúngicos/metabolismo , Burkholderia cenocepacia/metabolismo , Paenibacillus polymyxa/metabolismo , Pythium/crecimiento & desarrollo , Pythium/fisiología , Rhizoctonia/crecimiento & desarrollo , Rhizoctonia/fisiología , /microbiología
16.
Int J Biol Macromol ; 156: 1387-1395, 2020 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31760011

RESUMEN

Damping-off disease in seeds and young seedlings in agricultural crops is a major fungal disease that limits the agriculture production. Frequent use of synthetic fungicides against damping-off diseases is known to hamper the environmental balance. Thus, an alternative approach needs to be explored for the management of such economically important fungal diseases. In the present study, simple, economically feasible chitosan-coupled copper nanoparticles (Ch-CuNPs) were synthesized and demonstrated antifungal activity against damping-off disease causing phytopathogens, Rhizoctonia solani and Pythium aphanidermatum. Physico-chemical studies confirmed the size, shape, surface charge, element confirmation and mono-dispersed nature of Ch-CuNPs. In vitro efficacy studies revealed up to 98% mycelial growth inhibition at 0.1% Ch-CuNPs. An extracellular conductivity study of the mycelium showed cellular content leakage within 12 h of treatment. Further, plant toxicity study against chili, cowpea and tomato plants; showed that ≤0.2% NPs were safe under greenhouse conditions. NPs also exhibited growth-promoting activity with chili seeds, by overcoming the limited germination rate of susceptible seeds. Overall, the present study emphasizes the benefits of synthesized Ch-CuNPs on agricultural crops as fungicide and growth-promoter, as well as a safe alternative to pesticides in order to avoid hazardous effect on the environment.


Asunto(s)
Quitosano/química , Quitosano/farmacología , Cobre/química , Nanopartículas del Metal/química , Enfermedades de las Plantas/microbiología , Pythium/efectos de los fármacos , Rhizoctonia/efectos de los fármacos , Técnicas de Química Sintética , Estudios de Factibilidad , Nanotecnología , Pythium/fisiología , Rhizoctonia/fisiología , Propiedades de Superficie
17.
Mycopathologia ; 185(5): 801-812, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31845178

RESUMEN

Pythiosis is an emerging infectious disease caused by the aquatic oomycete Pythium insidiosum, a fungal-like organism. It is believed that P. insidiosum's zoospores, its infected form, play major role in pathogenesis. Vascular and ocular infections are the most common clinical manifestation in humans. It is difficult to establish the diagnosis given its relatively rarity and difficulty to distinguish P. insidiosum from other molds. Delay in diagnosis and treatment has been associated with poor outcomes. High index of suspicion is the key, particularly in thalassemia patients with arterial insufficiency and patients with fungal keratitis/endophthalmitis without improvement on antifungal therapy. Tissue culture and zoospore induction remain gold standard for diagnosis; however, DNA-based method should be performed simultaneously. The combination of radical surgery, antifungal agents, and immunotherapy has been recommended. It was previously believed that surgery with negative surgical margins was the essential to survive in vascular pythiosis; however, it was recently found that patients could have residual disease despite documented negative surgical margins as infected clot may be dislodged to proximal arterial sites prior to surgery. Serum ß-D-glucan (BG) has been used to monitor disease response after treatment initiation in vascular pythiosis. A significant decrease in BG levels within 2 weeks after surgery is indicative of the absence of residual infection. Unfortunately, monitoring tools for ocular pythiosis are not yet available. Itraconazole plus terbinafine have generally been used in P. insidiosum-infected patients; however, antibacterial agents, including azithromycin and linezolid, have also been used with favorable outcomes in ocular disease. Recently, azithromycin or clarithromycin plus doxycyclin were used in two relapsed vascular pythiosis patients with good outcomes.


Asunto(s)
Pitiosis , Pythium , Antibacterianos/uso terapéutico , Antifúngicos/farmacología , Enfermedades Transmisibles Emergentes/diagnóstico , Enfermedades Transmisibles Emergentes/terapia , Enfermedades Transmisibles Emergentes/transmisión , Combinación de Medicamentos , Infecciones Fúngicas del Ojo/diagnóstico , Infecciones Fúngicas del Ojo/terapia , Inmunoterapia/métodos , Itraconazol/farmacología , Oomicetos , Patología Molecular , Pitiosis/diagnóstico , Pitiosis/patología , Pitiosis/terapia , Pitiosis/transmisión , Pythium/efectos de los fármacos , Pythium/aislamiento & purificación , Pruebas Serológicas , Esporas Fúngicas/aislamiento & purificación , Terbinafina/farmacología , Talasemia/complicaciones , Lesiones del Sistema Vascular/diagnóstico , Lesiones del Sistema Vascular/microbiología , Lesiones del Sistema Vascular/terapia , beta-Glucanos/sangre
18.
Molecules ; 24(22)2019 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-31744250

RESUMEN

Pseudomonas species are metabolically robust, with capacity to produce secondary metabolites including cyclic lipopeptides (CLPs). Herein we conducted a chemical analysis of a crude CLP extract from the cocoyam rhizosphere-derived biocontrol strain Pseudomonas sp. COW3. We performed in silico analyses on its whole genome, and conducted in vitro antagonistic assay using the strain and purified CLPs. Via LC-MS and NMR, we elucidated the structures of four novel members of the bananamide group, named bananamides D-G. Besides variability in fatty acid length, bananamides D-G differ from previously described bananamides A-C and MD-0066 by the presence of a serine and aspartic acid at position 6 and 2, respectively. In addition, bananamide G has valine instead of isoleucine at position 8. Kendrick mass defect (KMD) allowed the assignment of molecular formulae to bananamides D and E. We unraveled a non-ribosomal peptide synthetase cluster banA, banB and banC which encodes the novel bananamide derivatives. Furthermore, COW3 displayed antagonistic activity and mycophagy against Pythium myriotylum, while it mainly showed mycophagy on Pyricularia oryzae. Purified bananamides D-G inhibited the growth of P. myriotylum and P. oryzae and caused hyphal distortion. Our study shows the complementarity of chemical analyses and genome mining in the discovery and elucidation of novel CLPs. In addition, structurally diverse bananamides differ in their antimicrobial activity.


Asunto(s)
Antiinfecciosos/química , Antiinfecciosos/farmacología , Lipopéptidos/química , Lipopéptidos/farmacología , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacología , Pseudomonas/metabolismo , Cromatografía Líquida de Alta Presión , Genes Bacterianos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Filogenia , Pseudomonas/clasificación , Pseudomonas/genética , Pythium/efectos de los fármacos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
19.
Int J Infect Dis ; 88: 27-30, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31493524

RESUMEN

Human vascular pythiosis is a life-threatening condition caused by Pythium insidiosum. Patients with unresectable intra-abdominal artery involvement have not previously survived, despite being treated with antifungal agents and immunotherapy. We report two novel cases of intra-abdominal pythiosis in patients for whom surgery could not be performed, who were successfully treated with adjunctive antibacterial agents.


Asunto(s)
Antibacterianos/uso terapéutico , Antifúngicos/uso terapéutico , Pitiosis/terapia , Pythium/efectos de los fármacos , Adulto , Animales , Humanos , Inmunoterapia , Masculino , Terapia Recuperativa
20.
An Acad Bras Cienc ; 91(2): e20180598, 2019 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-31271566

RESUMEN

We have established how natural compounds from green propolis collected by the species Apis mellifera act against the growth of Pythium aphanidermatum. On the basis of mass spectrometry (Q-ToF MS), we determined that Artepillin C, the major constituent of green propolis, underlies the effect and displays activity against P. aphanidermatum at a minimal inhibitory concentration of 750 µg.mL-1. Biophysical studies based on model membranes showed that this inhibitory effect may be linked with a membrane-related phenomenon: Artepillin C increases the permeability of membranes with relatively high fluidity in their lateral structure, a feature that is in line with the lipid composition reported for the cytoplasmic membrane of P. aphanidermatum. Therefore, the present study supports the use of the effective and inexpensive green propolis to control the impact of the dangerous phytopathogen P. aphanidermatum on agriculture.


Asunto(s)
Antifúngicos/farmacología , Fenilpropionatos/farmacología , Própolis/química , Pythium/efectos de los fármacos , Animales , Antifúngicos/aislamiento & purificación , Abejas , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Fenilpropionatos/aislamiento & purificación
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