Fungal keratitis caused by Macrophomina phaseolina - A case report.
ABSTRACT: A 70 year old female patient presented with complaints of pain, watering and swelling in the right eye. She gave a history of fall, as she was walking in the paddy field of her farm. Ophthalmological and Microbiological investigation revealed a fungal keratitis with an unusual fungus Macrophomina phaseolina which is primarily a plant pathogen, with a potential to cause human infections especially in immuno-compromised patients. The patient responded well to the antifungal treatment with Oral Voriconazole with absence of recurrence and dissemination.
Project description:Macrophomina phaseolina is one of the deadliest necrotrophic fungal pathogens that infect more than 500 plant species including major food, fiber, and oil crops all throughout the globe. It secretes a cocktail of ligninolytic enzymes along with other hydrolytic enzymes for degrading the woody lignocellulosic plant cell wall and penetrating into the host tissue. Among them, lignin peroxidase has been reported only in Phanerochaete chrysosporium so far. But interestingly, a recent study has revealed a second occurrence of lignin peroxidase in M. phaseolina. However, lignin peroxidases are of much significance biotechnologically because of their potential applications in bio-remedial waste treatment and in catalyzing difficult chemical transformations. Besides, this enzyme also possesses agricultural and environmental importance on account of their role in lignin biodegradation. In the present work, different properties of the lignin peroxidase of M. phaseolina along with predicting the 3-D structure and its active sites were investigated by the use of various computational tools. The data from this study will pave the way for more detailed exploration of this enzyme in wet lab and thereby facilitating the strategies to be designed against such deadly weapons of Macrophomina phaseolina. Furthermore, the insight of such a ligninolytic enzyme will contribute to the assessment of its potentiality as a bioremediation tool.
Project description:The deduced amino acid sequence derived from a Macrophomina phaseolina beta-1,4-endoglucanase-encoding gene revealed 48% identity (over 119 amino acids) with egl1 from the phytopathogen Pseudomonas solanacearum. Its similarity to saprophyte endoglucanases was not significant. Its minimum substrate size, unlike that of any known saprophyte endoglucanase, was cellopentaose. The unique characteristics of M. phaseolina egl1-encoded endoglucanase suggest that it is phytopathogen specific.
Project description:We report a case of Macrophomina phaseolina skin infection in an immunocompromised child with acute myeloid leukemia, which was treated successfully with posaconazole without recurrence after a hematopoietic stem cell transplant. The fungus was identified by DNA sequencing using both the internal transcribed spacer and D1/D2 region of the 28S ribosomal DNA gene.
Project description:Macrophomina phaseolina is the most devastating pathogen which causes charcoal rot and root rot diseases in various economically important crops. Three strains M. phaseolina 1156, M. phaseolina 1160, and M. phaseolina PCMC/F1 were tested for their virulence on sunflower (Helianthus annuus L.) and chickpea (Cicer arietinum L.). The strains showed high virulence on both hosts with a disease score of 2 on chickpea and sunflower. The strains also increased the hydrogen per oxide (H2O2) content by 1.4- to 1.6-fold in root as well as shoot of chickpea and sunflower. A significant increase in antioxidant enzymes was observed in fungal infected plants which indicated prevalence of oxidative stress during pathogen propagation. The M. phaseolina strains also produced hydrolytic enzymes such as lipase, amylase, and protease with solubilization zone of 5-43 mm, 5-45 mm, and 12-35 mm, respectively. The M. phaseolina strains were identified by 18S rRNA and analyzed for genetic diversity by using random amplified polymorphic DNA (RAPD) markers. The findings based on RAPD markers and 18S rRNA sequence analysis clearly indicate genetic variation among the strains collected from different hosts. The genetically diverse strains were found to be pathogenic to sunflower and chickpea.
Project description:<h4>Background</h4>Macrophomina phaseolina is one of the most destructive necrotrophic fungal pathogens that infect more than 500 plant species throughout the world. It can grow rapidly in infected plants and subsequently produces a large amount of sclerotia that plugs the vessels, resulting in wilting of the plant.<h4>Results</h4>We sequenced and assembled ~49 Mb into 15 super-scaffolds covering 92.83% of the M. phaseolina genome. We predict 14,249 open reading frames (ORFs) of which 9,934 are validated by the transcriptome. This phytopathogen has an abundance of secreted oxidases, peroxidases, and hydrolytic enzymes for degrading cell wall polysaccharides and lignocelluloses to penetrate into the host tissue. To overcome the host plant defense response, M. phaseolina encodes a significant number of P450s, MFS type membrane transporters, glycosidases, transposases, and secondary metabolites in comparison to all sequenced ascomycete species. A strikingly distinct set of carbohydrate esterases (CE) are present in M. phaseolina, with the CE9 and CE10 families remarkably higher than any other fungi. The phenotypic microarray data indicates that M. phaseolina can adapt to a wide range of osmotic and pH environments. As a broad host range pathogen, M. phaseolina possesses a large number of pathogen-host interaction genes including those for adhesion, signal transduction, cell wall breakdown, purine biosynthesis, and potent mycotoxin patulin.<h4>Conclusions</h4>The M. phaseolina genome provides a framework of the infection process at the cytological and molecular level which uses a diverse arsenal of enzymatic and toxin tools to destroy the host plants. Further understanding of the M. phaseolina genome-based plant-pathogen interactions will be instrumental in designing rational strategies for disease control, essential to ensuring global agricultural crop production and security.
Project description:UNLABELLED: BACKGROUND: Biotransformation offers chemo enzymatic system to modify the compounds into their novel analogues which are difficult to synthesize by chemical methods. This paper describes the biotransformational studies of ambrox, one of the most important components of natural Ambergris (wale sperm) with fungal and plant cell culture. RESULTS: Biotransformation of (-)-ambrox (1) with a fungal cell culture of Macrophomina phaseolina and a plant cell suspension cultures of Peganum harmala yielded oxygenated products, 3?-hydroxyambrox (2), 6?-hydroxyambrox (3), 1?-hydroxy-3oxoambrox (4), 1?,3?-dihydroxyambrox (5), 13,14,15,16-tetranorlabdane-3-oxo-8,12-diol (6), 3-oxoambrox (7), 2?-hydroxyambrox (8), 3?-hydroxysclareolide (9), and 2?,3?-dihydroxyambrox (10). Metabolite 4 was found to be new compound. These metabolites were structurally characterized on the basis of spectroscopic studies. CONCLUSION: Nine oxygenated metabolites of (-)-ambrox (1) were obtained from Macrophomina phaseolina and Peganum harmala. Enzymatic system of screened organisms introduced hydroxyl and keto functionalities at various positions of compound 1 in a stereo- and regio-controlled manner.
Project description:A halotolerant actinobacterial strain isolated from salinity affected soil of Eastern Indo-Gangetic plains (IGP), Uttar Pradesh, India, was characterised for its antagonistic potential against Macrophomina phaseolina by dual-culture assay. It was shown to effectively inhibit the growth of M. phaseolina with an inhibition zone of 27 ± 1.33 mm. Further the actinobacterial strain was evaluated for its plant growth promoting (PGP) properties and its ability to produce biocontrol related extracellular enzymes viz. amylase, protease, cellulase, chitinase, gelatinase and urease. The results revealed that the actinobacterial strain had PGP potential along with positive assay for amylase, chitinase and urease. The interaction study between antagonist strain and fungal pathogen, performed by scanning electron microscopy technique revealed that the actinobacterium was able to damage fungal mycelia may be due to chitinase, establishing its role as a potential antagonist against M. phaseolina. The actinobacterial isolate was characterised by 16S rDNA gene sequencing, and was identified as Streptomyces genera. The identified gene sequence was deposited to NCBI GenBank with an accession number KP331758.
Project description:The worldwide demand for natural bast fibers is met aptly by the long, golden and silky fibers of jute. This highest bast fiber producing crop is of great applicability and is extensively used in paper and textile industry. Macrophomina phaseolina (Tassi) Goid is a severely devastating necrotrophic fungal pathogen causing stem rot, root rot, and charcoal rot diseases in both the cultivated species of jute - Corchorus capsularis and Corchorus olitorius. Another major problem faced in jute cultivation is profuse weed infestation in the fields. Huge losses in quality fiber production is caused by this pathogenic fungi and cultivation cost increases as well due to weed management expenditure during cropping season. To solve these long persisting jute cultivation challenges, the chitinase (chi11) gene (to provide fungus resistance) and the bar gene (to provide herbicide tolerance) have been incorporated in C. capsularis JRC-321 via Agrobacterium transformation and analyzed up to T2 generation. Stable integration and expression of these two genes in the jute genome was confirmed upon extensive analyses. Transgenic plants showed higher chitinase expression and chitin degrading activity than non-transgenic control plants. Antifungal activity significantly increased in transgenic plants as confirmed by detached leaf and whole plant M. phaseolina bioassay. Herbicide tolerance was analyzed by growing transgenic plants in 10 mg/l glufosinate ammonium containing media and by spraying 0.25% (v/v) glufosinate herbicide Basta® on them. Assessment of residual phytotoxicity effects of Basta® on soil confirmed no negative impact on growth of indicator plants corn and cucumber. Transgenic jute plants were at par with non-transgenic (control) jute plants in all phenotypic aspects. Non-transgenic (control) jute plants suffered significant losses in fiber yield and quality due to M. phaseolina infection whereas the transgenic lines maintained the quality of fiber even after the infection.