5 results on '"Sana Azaiez"'
Search Results
2. Bacillomycin D and its combination with amphotericin B: promising antifungal compounds with powerful antibiofilm activity and wound-healing potency
- Author
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Bruno Casciaro, I. Ben Slimene, A. Di Grazia, Sana Azaiez, Ines Karkouch, Ferid Limam, Maria Luisa Mangoni, Vincenzo Luca, Olfa Tabbene, M. N. Alfeddy, and Salem Elkahoui
- Subjects
0301 basic medicine ,amphotericin b ,anti-biofilm ,bacillomycin d ,candida albicans ,synergy ,wound healing ,applied microbiology and biotechnology ,biotechnology ,Antifungal Agents ,030106 microbiology ,Antifungal drug ,Germ tube ,Microbial Sensitivity Tests ,Pharmacology ,Biology ,Applied Microbiology and Biotechnology ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Amphotericin B ,Candida albicans ,medicine ,Humans ,Potency ,Wound Healing ,Candidiasis ,Biofilm ,Lipopeptide ,General Medicine ,biology.organism_classification ,Corpus albicans ,030104 developmental biology ,chemistry ,Biofilms ,Drug Therapy, Combination ,Peptides ,Antimicrobial Cationic Peptides ,Biotechnology ,medicine.drug - Abstract
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.
- Published
- 2016
3. Biological control of the soft rot bacterium Pectobacterium carotovorum by Bacillus amyloliquefaciens strain Ar10 producing glycolipid-like compounds
- Author
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Selim Jallouli, Sana Azaiez, Salem Elkahoui, Olfa Tabbene, Ferid Limam, Imen Ben Slimene, Naceur Djébali, Ines Karkouch, and Rym Essid
- Subjects
0301 basic medicine ,Bacillus amyloliquefaciens ,030106 microbiology ,Pectobacterium carotovorum ,Microbial Sensitivity Tests ,Biology ,Microbiology ,Plant Roots ,03 medical and health sciences ,Bacterial soft rot ,Glycolipid ,Endophytes ,Antibacterial agent ,Plant Diseases ,Solanum tuberosum ,Strain (chemistry) ,food and beverages ,biology.organism_classification ,Anti-Bacterial Agents ,Kinetics ,Biological Control Agents ,Glycolipids ,Antibacterial activity ,Bacteria - Abstract
Four hundred and fifty bacteria were evaluated for antagonistic activity against bacterial soft rot of potato caused by Pectobacterium carotovorum sp strain II16. A strain Ar10 exhibiting potent antagonist activity has been identified as Bacillus amyloliquefaciens on the basis of biochemical and molecular characterization. Cell free supernatant showed a broad spectrum of antibacterial activity against human and phytopathogenic bacteria in the range of 10-60 AU/mL. Incubation of P. carotovorum cells with increasing concentrations of the antibacterial compound showed a killing rate of 94.8 and 96% at MIC and 2xMIC respectively. In addition, the antibacterial agent did not exert haemolytic activity at the active concentration and has been preliminary characterized by TLC and GC–MS as a glycolipid compound. Treatment of potato tubers with strain Ar10 for 72 h significantly reduced the severity of disease symptoms (100 and 85.05% reduction of necrosis deep / area and weight loss respectively). The same levels in disease symptoms severity was also recorded following treatment of potato tubers with cell free supernatant for 1 h. Data suggest that protection against potato soft rot disease may be related to glycolipid production by strain Ar10. The present study affords new alternatives for anti-Pectobacterium carotovorum bioactive compounds against the soft rot disease of potato.
- Published
- 2018
4. Enhancement of Exochitinase Production by Bacillus licheniformis AT6 Strain and Improvement of N-Acetylglucosamine Production
- Author
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Olfa Tabbene, Sana Azaiez, Imen Ben Slimene-Debez, Dorra Gharbi, Kais Djebali, Ferid Limam, Majdi Hammami, and Mohamed Amine Aounallah
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0106 biological sciences ,0301 basic medicine ,Bioengineering ,Biology ,01 natural sciences ,Applied Microbiology and Biotechnology ,Biochemistry ,Acetylglucosamine ,03 medical and health sciences ,chemistry.chemical_compound ,Species Specificity ,Glucosamine ,010608 biotechnology ,N-Acetylglucosamine ,Yeast extract ,Bacillus licheniformis ,Response surface methodology ,Molecular Biology ,Solanum tuberosum ,Strain (chemistry) ,General Medicine ,biology.organism_classification ,Culture Media ,030104 developmental biology ,Hexosaminidases ,chemistry ,Chitinase ,biology.protein ,Fermentation ,Biotechnology - Abstract
A strain producing chitinase, isolated from potato stem tissue, was identified as Bacillus licheniformis by biochemical properties and 16S RNA sequence analysis. Statistical experimental designs were used to optimize nine independent variables for chitinase production by B. licheniformis AT6 strain in submerged fermentation. Using Plackett–Burman design, (NH4)2SO4, MgSO4.7H2O, colloidal chitin, MnCl2 2H2O, and temperature were found to influence chitinase production significantly. According to Box–Behnken response surface methodology, the optimal fermentation conditions allowing maximum chitinase production were (in gram per liter): (NH4)2SO4, 7; K2HPO4, 1; NaCl, 1; MgSO4.7H2O, 0.1; yeast extract, 0.5; colloidal chitin, 7.5; MnCl2.2H2O, 0.2; temperature 35 °C; pH medium 7. The optimization strategy led to a 10-fold increase in chitinase activity (505.26 ± 22.223 mU/mL versus 50.35 ± 19.62 mU/mL for control basal medium). A major protein band with a molecular weight of 61.9 kDa corresponding to chitinase activity was clearly detected under optimized conditions. Chitinase activity produced in optimized medium mainly releases N-acetyl glucosamine (GlcNAc) monomer from colloidal chitin. This enzyme also acts as an exochitinase with β-N-acetylglucosaminidase. These results suggest that B. licheniformis AT6 secreting exochitinase is highly efficient in GlcNAc production which could in turn be envisaged as a therapeutic agent or as a conservator against the alteration of several ailments.
- Published
- 2016
5. Antifungal activity of volatile compounds-producing Pseudomonas P2 strain against Rhizoctonia solani
- Author
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Najeh Yaich, Ferid Limam, Naceur Djébali, Sana Azaiez, Majdi Hammami, Rym Essid, and Salem Elkahoui
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DNA, Bacterial ,Siderophore ,Antifungal Agents ,Physiology ,Molecular Sequence Data ,Applied Microbiology and Biotechnology ,Endophyte ,DNA, Ribosomal ,Microbiology ,Rhizoctonia ,Rhizoctonia solani ,chemistry.chemical_compound ,Pseudomonas ,RNA, Ribosomal, 16S ,Cluster Analysis ,Dimethyl disulfide ,Mycelium ,Phylogeny ,Base Composition ,Microscopy ,Volatile Organic Compounds ,biology ,fungi ,food and beverages ,General Medicine ,Sequence Analysis, DNA ,biology.organism_classification ,Olive trees ,Bacterial Typing Techniques ,chemistry ,Dimethyl trisulfide ,Biotechnology - Abstract
Several volatile organic compounds (VOCs) producing endophyte bacteria were isolated from the leaves of olive trees and tested for their antifungal activity against several pathogenic fungi. An antagonistic strain called P2 showed 97 % of homology with Pseudomonas sp. strains on the basis of its 16S rDNA sequence and biochemical properties. P2 strain drastically inhibited the growth of Rhizoctonia solani mycelia (86 %) at 5 day-post-confrontation (dpc) and strongly reduced fungi infection on potato slices at 10(7) bacteria ml(-1) for 3 and 7 dpc. P2 strain was also positive for protease activity as well as siderophore production. Light microscopy analysis showed that treatment of R. solani mycelia with P2 strain induced thickening of the cell-wall, vesiculation of protoplasm and blockage of fungal hyphae branching. VOCs analysis using GC-MS allowed the detection of two major products with m/z of 93.9910 and 125.9630 corresponding to dimethyl disulfide and dimethyl trisulfide respectively. VOCs-producing P2 strain could be a promising agent in the protection of tuber crops against fungal diseases.
- Published
- 2014
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