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1.
J Appl Microbiol ; 134(11)2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37884451

RESUMEN

AIM: The present study aimed to investigate a novel antifungal compound produced by Streptomyces blastmyceticus S108 strain. Its effectiveness against clinical isolates of Candida species and its synergistic effect with conventional antifungal drugs were assessed, and its molecular mechanism of action was further studied against Candida albicans. METHODS AND RESULTS: A newly isolated strain from Tunisian soil, S. blastmyceticus S108, showed significant antifungal activity against Candida species by well diffusion method. The butanolic extract of S108 strain supernatant exhibited the best anti-Candida activity with a minimal inhibitory concentration (MIC) value of 250 µg ml-1, determined by the microdilution method. The bio-guided purification steps of the butanolic extract were performed by chromatographic techniques. Among the fractions obtained, F13 demonstrated the highest level of activity, displaying a MIC of 31.25 µg ml-1. Gas chromatography-mass spectrometry and electrospray ionization mass spectrometry analyses of this fraction (F13) revealed the glycolipidic nature of the active molecule with a molecular weight of 685.6 m/z. This antifungal metabolite remained stable to physicochemical changes and did not show hemolytic activity even at 4MIC corresponding to 125 µg ml-1 toward human erythrocytes. Besides, the glycolipid compound was combined with 5-flucytosine and showed a high synergistic effect with a fractional inhibitory concentration index value 0.14 against C. albicans ATCC 10231. This combination resulted in a decrease of MIC values of 5-flucytosine and the glycolipid-like compound by 8- and 64-fold, respectively. The examination of gene expression in treated C. albicans cells by quantitative polymerase chain reaction (qPCR) revealed that the active compound tested alone or in combination with 5-flucytosine blocks the ergosterol biosynthesis pathway by downregulating the expression of ERG1, ERG3, ERG5, ERG11, and ERG25 genes. CONCLUSION AND IMPACT OF THE STUDY: The new glycolipid-like compound, produced by Streptomyces S108 isolate, could be a promising drug for medical use against pathogenic Candida isolates.


Asunto(s)
Antifúngicos , Streptomyces , Humanos , Antifúngicos/química , Flucitosina/farmacología , Candida , Streptomyces/genética , Candida albicans , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/farmacología
2.
J Appl Microbiol ; 120(2): 289-300, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26669801

RESUMEN

AIMS: In this study, we evaluated the ability of the lipopeptide bacillomycin D and the antifungal drug amphotericin B as well as their combination, to inhibit Candida albicans biofilm formation and to accelerate keratinocyte cell migration. METHODS AND RESULTS: The antibiofilm activity of bacillomycin D and its combination with amphotericin B was carried out by crystal violet colorimetric method. Our results have shown that, when combined together at low concentrations nontoxic to mammalian cells, corresponding to 1/32 MIC (0·39 µg ml(-1) ) and 1/4 MIC (0·06 µg ml(-1) ) for bacillomycin D and amphotericin B, respectively, a clear antibiofilm activity is manifested (95% inhibition of biofilm formation) along with a clear inhibition of germ tube formation. Moreover, the effect of both drugs on preformed biofilm of C. albicans strain was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. The combination of the two antifungal compounds at 0·39 and 1 µg ml(-1) for bacillomycin D and amphotericin B, respectively, resulted in a clear enhancement of biofilm eradication compared to the results obtained with each drug alone. Furthermore, this combination was found to promote the closure of a gap produced in a monolayer of human keratinocytes. CONCLUSIONS: Bacillomycin D and its combination with amphotericin B display impressive anti-biofilm and wound-healing activities. SIGNIFICANCE AND IMPACT OF THE STUDY: Application of the lipopeptide bacillomycin D and the antifungal drug amphotericin B in medical devices may offer a promising alternative for topical treatment of Candida-associated infections in the setting of a wound.


Asunto(s)
Anfotericina B/farmacología , Antifúngicos/farmacología , Biopelículas/efectos de los fármacos , Candida albicans/efectos de los fármacos , Candidiasis/microbiología , Péptidos/farmacología , Cicatrización de Heridas/efectos de los fármacos , Péptidos Catiónicos Antimicrobianos , Candida albicans/fisiología , Candidiasis/tratamiento farmacológico , Candidiasis/fisiopatología , Quimioterapia Combinada , Humanos , Pruebas de Sensibilidad Microbiana
3.
Prikl Biokhim Mikrobiol ; 50(2): 184-8, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25272736

RESUMEN

This work aims to characterize the bioactive molecules produced by an antagonistic Bacillus sp. strain BCLRB2 isolated from healthy leaves of olive tree against Rhizoctonia solani and Sclerotinia sclerotiorum. The bacterial strain isolated showed a high and persistent antifungal activity against the two pathogens. The free-cell supernatant showed also a high antifungal activity against R. solani and at a lower extent against S. sclerotiorum. The partial purification of the antifungal substances with methanol gradient applied to C18 column binding the Bacillus BCLRB2 culture supernatant showed that the 20% and 60% methanol fractions had a high and specific activity against S. sclerotiorum and R. solani, respectively. The mass spectrometry identification of the compounds in the fraction specifically active against S. sclerotiorum revealed the presence of bacillomycin D C16 as a major lipopeptide. The fraction specifically active against R. solani contained bacillomycin D C15 and 2 unknown lipopeptides. The 80% methanol fraction had a moderate and a broad spectrum activity against the two pathogens and consisted from two iturin D (C13 and C14) as a major lipopeptides.


Asunto(s)
Antifúngicos/química , Bacillus/metabolismo , Lipopéptidos/química , Rhizoctonia/efectos de los fármacos , Saccharomycetales/efectos de los fármacos , Antibiosis , Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Péptidos Catiónicos Antimicrobianos , Bacillus/patogenicidad , Agentes de Control Biológico , Medios de Cultivo Condicionados/química , Lipopéptidos/aislamiento & purificación , Lipopéptidos/farmacología , Espectrometría de Masas , Metanol , Olea/microbiología , Péptidos/química , Péptidos/aislamiento & purificación , Péptidos/farmacología , Péptidos Cíclicos/química , Péptidos Cíclicos/aislamiento & purificación , Péptidos Cíclicos/farmacología , Rhizoctonia/crecimiento & desarrollo , Saccharomycetales/crecimiento & desarrollo , Solventes
4.
World J Microbiol Biotechnol ; 30(2): 529-38, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23990072

RESUMEN

Isolate TEB1 an antagonistic endophytic bacterium, obtained from citrus leaves and identified as Bacillus amyloliquefaciens by 16S rDNA sequencing, was used for the biological control of mal secco disease of Citrus aurantium seedlings caused by the mitosporic fungus Phoma tracheiphila. The isolate TEB1 exhibited a good in vitro activity against P. tracheiphila in dual cultures as well as with the well diffusion method. C. aurantium seedlings watered with a suspension of TEB1 cells showed a reduction of 53.61 and 48.63% in disease severity and incidence, respectively. A PCR test with specific primers was performed 365 days after inoculation and P. tracheiphila was detected along the whole stem in inoculated control plant while no amplification product was obtained in TEB1 treated seedlings. Molecular analysis of TEB1 revealed a positive amplification of fenD and ituC genes responsible of the biosynthesis of fengycin and iturin lipopeptides, respectively. Moreover, observations by optical microscope showed that TEB1 reduced by 55% the germination of P. tracheiphila conidia and exhibited a marked effect on mycelia structure. Data suggest that lipopeptides produced by the bacterium interact with the cytoplasmic membrane of the fungus causing pore formation. TEB1 appears a potential candidate for the biological control of citrus mal secco disease.


Asunto(s)
Antibiosis , Ascomicetos/crecimiento & desarrollo , Bacillus/fisiología , Citrus/microbiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Antifúngicos/metabolismo , Antifúngicos/farmacología , Ascomicetos/efectos de los fármacos , Bacillus/clasificación , Bacillus/genética , Bacillus/aislamiento & purificación , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Lipopéptidos/genética , Lipopéptidos/metabolismo , Lipopéptidos/farmacología , Datos de Secuencia Molecular , Micelio/efectos de los fármacos , Micelio/crecimiento & desarrollo , Péptidos Cíclicos/genética , Péptidos Cíclicos/metabolismo , Péptidos Cíclicos/farmacología , ARN Ribosómico 16S/genética , Plantones/microbiología , Análisis de Secuencia de ADN
5.
J Physiol Pharmacol ; 63(4): 381-8, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23070087

RESUMEN

High garlic dose could exert adverse health properties and grape seed and skin extract (GSSE) exhibit a variety of beneficial effects, even at high dose. In the present study we evaluated the toxic effect of high garlic dose treatment on antioxidant status of the blood compartment and the protective effect of GSSE. Rats were intraperitoneally (i.p.) administered either with garlic extract (5 g/kg bw) or GSSE (500 mg/kg bw) or a combination of garlic and GSSE at the same doses daily during one month. Plasma parameters and erythrocytes antioxidant status were evaluated. Data confirmed that high garlic dose induced anemia and a pro-oxidative state into erythrocytes characterized by increased malondialdehyde (MDA), carbonyl protein and antioxidant enzyme activities as catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD). Garlic also elevated intracellular hydrogen peroxide (H(2)O(2)) and free iron whereas GSSE treatment counteracted almost all garlic deleterious effects. In conclusion, high garlic dose induced a pro-oxidative state into erythrocytes via the Fenton reaction between H(2)O(2) and free iron, and GSSE exerted antioxidant properties.


Asunto(s)
Eritrocitos/efectos de los fármacos , Ajo , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/farmacología , Sustancias Protectoras/farmacología , Vitis , Animales , Calcio/sangre , Catalasa/sangre , Eritrocitos/metabolismo , Frutas , Peróxido de Hidrógeno/sangre , Hierro/sangre , Masculino , Peroxidasa/sangre , Carbonilación Proteica , Ratas , Ratas Wistar , Semillas , Superóxido Dismutasa/sangre
6.
J Physiol Pharmacol ; 63(3): 293-301, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22791644

RESUMEN

Doxorubicin (Dox), a widely used antitumor anthracycline antibiotic, plays an undisputed key role in the treatment of many neoplasic diseases. In this study, the protective role of resveratrol against Dox-induced erythrocytes and plasma toxicity has been evaluated in rats. Animals were treated with resveratrol (25 mg/kg b.w.) by intraperitoneal injection during 8 days. At the 4(th) day of treatment, rats were intraperitoneally injected with a single dose of Dox (20 mg/kg b.w.). At the end of the treatment, blood samples were collected following standard procedure and processed for oxidative stress parameters (malondialdehyde (MDA), carbonyl protein, free iron, calcium and H(2)O(2) levels), transaminases and antioxidant enzymes as catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD). Data showed that Dox drastically increased erythrocytes and plasma MDA, free iron, H(2)O(2) and carbonyl proteins but decreased calcium levels and also decreased erythrocytes CAT, POD and SOD activity. Besides, Dox decreased plasma CAT and SOD but unexpectedly increased POD activity. Dox also increased plasma ALT and AST levels and decreased them into erythrocytes. Co-treatment with resveratrol counteracted almost all Dox's effects. In conclusion, Dox induced a pro-oxidative stress into erythrocytes and resveratrol exerted real antioxidant properties which can be attributed, at least in part, to free iron and calcium modulation.


Asunto(s)
Antibióticos Antineoplásicos/efectos adversos , Doxorrubicina/toxicidad , Eritrocitos/efectos de los fármacos , Estilbenos/farmacología , Alanina Transaminasa/sangre , Alanina Transaminasa/metabolismo , Animales , Antioxidantes/metabolismo , Aspartato Aminotransferasas/sangre , Aspartato Aminotransferasas/metabolismo , Calcio/sangre , Calcio/metabolismo , Catalasa/sangre , Catalasa/metabolismo , Doxorrubicina/sangre , Eritrocitos/metabolismo , Femenino , Peróxido de Hidrógeno/sangre , Peróxido de Hidrógeno/metabolismo , Hierro/sangre , Hierro/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Malondialdehído/sangre , Estrés Oxidativo/efectos de los fármacos , Carbonilación Proteica/efectos de los fármacos , Ratas , Ratas Wistar , Resveratrol , Estilbenos/sangre , Superóxido Dismutasa/sangre , Superóxido Dismutasa/metabolismo
7.
Phytomedicine ; 18(11): 976-84, 2011 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-21466954

RESUMEN

The present study reports for the first time, the in vivo wound healing potential of Punica granatum L. peels. A 5% (w/w) methanolic extract based-ointment was formulated and evaluated for its wound healing in guinea pigs. The ointment was applied in vivo on the paravertebral area of twelve excised wounded models once a day for 10 consecutive days. The ointment significantly enhanced the wound contraction and the period of epithelialization as assessed by the mechanical (contraction rate, tensile strength), the biochemical (increasing of collagen, DNA and proteins synthesis) and the histopathological characteristics. Such investigation was encouraged by the efficiency of the methanolic extract as antimicrobial and antioxidant. Indeed, the extract showed antioxidant activity as strong as natural and synthetic compounds (Trolox, BHA, Quercetin). Furthermore, the extract exhibited significant antibacterial and antifungal activity against almost all tested bacteria: Pseudomonas aeruginosa ATCC 9027, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Klebsiella pneumoniae, Salmonella anatum, Salmonella typhimurium, Streptococcus pneumoniae, and fungi Candida albicans, Candida glabrata, Trichopyton rubrum and Aspergillus niger. The formulated ointment might well find use as skin repair agent without hazard to human health based on these results and on the fact that it has been well established that the extracts of pomegranate used in conditions similar to those applied by traditional medicine, showed no toxic effects.


Asunto(s)
Lythraceae/química , Extractos Vegetales/farmacología , Piel/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos , Heridas y Lesiones/tratamiento farmacológico , Animales , Antiinfecciosos/farmacología , Antioxidantes/metabolismo , Cromatografía Líquida de Alta Presión , Femenino , Cobayas , Masculino , Pruebas de Sensibilidad Microbiana/métodos , Pomadas/química , Pomadas/farmacología , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Piel/lesiones , Resistencia a la Tracción
8.
Plant Biol (Stuttg) ; 7(4): 358-68, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16025408

RESUMEN

The effects of cadmium (Cd) uptake on ultrastructure and lipid composition of chloroplasts were investigated in 28-day-old tomato plants (Lycopersicon esculentum var. Ibiza F1) grown for 10 days in the presence of various concentrations of CdCl2. Different growth parameters, lipid and fatty acid composition, lipid peroxidation, and lipoxygenase activity were measured in the leaves in order to assess the involvement of this metal in the generation of oxidative stress. We first observed that the accumulation of Cd increased with external metal concentration, and was considerably higher in roots than in leaves. Cadmium induced a significant inhibition of growth in both plant organs, as well as a reduction in the chlorophyll and carotenoid contents in the leaves. Ultrastructural investigations revealed that cadmium induced disorganization in leaf structure, essentially marked by a lowered mesophyll cell size, reduced intercellular spaces, as well as severe alterations in chloroplast fine structure, which exhibits disturbed shape and dilation of thylakoid membranes. High cadmium concentrations also affect the main lipid classes, leading to strong changes in their composition and fatty acid content. Thus, the exposure of tomato plants to cadmium caused a concentration-related decrease in the fatty acid content and a shift in the composition of fatty acids, resulting in a lower degree of fatty acid unsaturation in chloroplast membranes. The level of lipid peroxides and the activity of lipoxygenase were also significantly enhanced at high Cd concentrations. These biochemical and ultrastructural changes suggest that cadmium, through its effects on membrane structure and composition, induces premature senescence of leaves.


Asunto(s)
Cloruro de Cadmio/farmacología , Cloroplastos/efectos de los fármacos , Metabolismo de los Lípidos , Solanum lycopersicum/efectos de los fármacos , Carotenoides/metabolismo , Clorofila/metabolismo , Cloroplastos/metabolismo , Cloroplastos/ultraestructura , Relación Dosis-Respuesta a Droga , Membranas Intracelulares/efectos de los fármacos , Membranas Intracelulares/metabolismo , Membranas Intracelulares/ultraestructura , Solanum lycopersicum/metabolismo , Solanum lycopersicum/ultraestructura , Proteínas de Plantas/metabolismo
9.
Rev Pneumol Clin ; 59(4): 209-12, 2003 Sep.
Artículo en Francés | MEDLINE | ID: mdl-14699298

RESUMEN

A 22-month-old infant developed purulent pleurisy caused by Streptococcus pneumoniae and a hemolytic uremic syndrome. The diagnosis was suggested by the classical triad: hemolytic anemia, renal failure and thrombocytemia confirmed by renal biopsy which demonstrated extensive cortical necrosis. Renal involvement was severe, justifying an indication for renal transplantation.


Asunto(s)
Síndrome Hemolítico-Urémico/complicaciones , Pleuresia/etiología , Neumonía Neumocócica/etiología , Humanos , Lactante , Masculino , Pleuresia/microbiología , Supuración/etiología
10.
Phytochemistry ; 49(5): 1219-25, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9842727

RESUMEN

Peroxidase (POD) activity was investigated in Catharanthus roseus cell suspensions cultured under different hormonal conditions. Depletion of 2,4-dichlorophenoxyacetic acid (2,4-D) from the culture medium enhanced POD activity in cells and spent medium. Addition of phytohormones, in particular the auxin 2,4-D, reduced POD activity in medium and cellular compartments and enhanced ionically cell-wall bound POD. The differential modulation of POD is due to hormone effects on synthesis and/or accumulation of POD, rather than on the secretion process. Qualitative analysis showed that 2,4-D, but not cytokinins, regulated the synthesis of a basic isoform. The cytokinin treatment seemed to affect acidic rather than basic isoforms. The presence of basic POD is correlated with the capacity of cells to produce indole alkaloids. The major extracellular basic isoperoxidase was purified to homogeneity from culture medium of Catharanthus roseus cell suspensions. The isolated peroxidase is a haem protein with a M(r) of 33,000 and a pI close to 9. The effect of pH on peroxidase activity was studied using guaiacol as substrate and the optimum pH determined at 25 degrees was 6.0. This enzyme acted on guaiacol, 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), o-dianisidine, o-phenylenediamine (o-PD) and pyrogallol, but had no effect on syringaldazine or coniferyl alcohol substrates.


Asunto(s)
Citocininas/fisiología , Ácidos Indolacéticos/fisiología , Isoenzimas/metabolismo , Peroxidasas/metabolismo , Proteínas de Plantas/metabolismo , Plantas/enzimología , Ácido 2,4-Diclorofenoxiacético/farmacología , Alcaloides/biosíntesis , Pared Celular/metabolismo , Células Cultivadas , Fenómenos Químicos , Química Física , Medios de Cultivo , Electroforesis en Gel de Poliacrilamida , Herbicidas/farmacología , Focalización Isoeléctrica , Isoenzimas/aislamiento & purificación , Peroxidasas/aislamiento & purificación , Proteínas de Plantas/aislamiento & purificación , Plantas/metabolismo , Dodecil Sulfato de Sodio
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