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Beta-D-glucose is the basic subunit of cellulose, which is an important component of the cyst wall of Acanthamoeba .
Source publication
Acanthamoeba is an opportunistic free-living amoeba that can cause blinding keratitis and fatal brain infection. Early diagnosis, followed by aggressive treatment is a pre-requisite in the successful treatment but even then the prognosis remains poor. A major drawback during the course of treatment is the ability of the amoeba to enclose itself wit...
Citations
... It assumed that the positive charge of chitosan nanoparticles allows attachment to the negatively charged cyst wall. Nonetheless, the drug penetration into the double-layered cellulose wall of the cyst is complex and requires more prolonged exposure [58]. Previous studies on different antimicrobial agents revealed that the cysticidal concentration is generally higher than the trophozoicidial concentration; thus, more prolonged drug exposure was needed in in-vitro and clinical cases to vanish the cyst form [59]. ...
Background
Acanthamoeba keratitis (AK) is a corneal sight-threatening infection caused by the free-living amoebae of the genus Acanthamoeba . Early and appropriate treatment significantly impacts visual outcomes. Mucoadhesive polymers such as chitosan are a potential strategy to prolong the residence time and bioavailability of the encapsulated drugs in the cornea. Regarding the recent administration of miltefosine (MF) for treating resistant AK, in the present study, we synthesized miltefosine-loaded chitosan nanoparticles (MF-CS-NPs) and evaluated them against Acanthamoeba .
Methodology/Principal findings
Chitosan nanoparticles (CNPs) were prepared using the ionic gelation method with negatively charged tripolyphosphate (TPP). The zeta-potential (ZP) and the particle size of MF-CS-NPs were 21.8±3.2 mV and 46.61±18.16 nm, respectively. The release profile of MF-CS-NPs indicated linearity with sustained drug release. The cytotoxicity of MF-CS-NPs on the Vero cell line was 2.67 and 1.64 times lower than free MF at 24 and 48 hours. This formulation exhibited no hemolytic activity in vitro and ocular irritation in rabbit eyes. The IC 50 of MF-CS-NPs showed a significant reduction by 2.06 and 1.69-fold in trophozoites at 24 and 48 hours compared to free MF. Also, the MF-CS-NPs IC 50 in the cysts form was slightly decreased by 1.26 and 1.21-fold at 24 and 48 hours compared to free MF.
Conclusions
The MF-CS-NPs were more effective against the trophozoites and cysts than free MF. The nano-chitosan formulation was more effective on trophozoites than the cysts form. MF-CS-NPs reduced toxicity and improved the amoebicidal effect of MF. Nano-chitosan could be an ideal carrier that decreases the cytotoxicity of miltefosine. Further analysis in animal settings is needed to evaluate this nano-formulation for clinical ocular drug delivery.
... Xanthyletin, a natural component of green plants, is a coumarin derivative with anti-Pythium properties. [82] The streptomyces species have proved effective as a biocontrol agent against Pythium and are shown to produce enzymes that cause cell wall rupture. S. rubrolavendulae S4 was reported to have a very high cellulase activity and inhibit Pythium growth. ...
Pythium insidiosum, an oomycete, is frequently referred to as a “parafungus” due to its striking similarity to fungal keratitis. Over the past 10 years, there has been a significant rise in Pythium insidiosum keratitis (PIK) cases, notably in Asia and India. This trend is potentially attributable to heightened research interest in this microorganism and advancements in diagnostic and therapeutic techniques. Clinically, its features, such as subepithelial infiltration, fluffy stromal infiltrates resembling cotton wool, satellite lesions, corneal perforation, endoexudates, and anterior chamber hypopyon, mirror those of fungal infections. However, hallmark clinical features like reticular dots, tentacular extensions, peripheral indentation, and prompt limbal progression distinguish Pythium from other pathogens and necessitate vigilant clinical scrutiny. From a morphological and microbiological perspective, Pythium closely mirrors fungi when subjected to routine smear tests, often revealing perpendicular or obtuse septate or non-septate branching hyphae. Culturing on nutritional media like blood agar, chocolate agar, and so on remains the diagnostic gold standard, with the organism presenting as cream-white colonies that form zoospores. This can be further verified through the leaf incarnation technique. Culture and polymerase chain reaction (PCR) are the gold standard diagnostic modalities for PIK. Historically, due to constraints in diagnostic techniques and the slow growth of cultures, there has been a trend toward employing advanced molecular diagnostic tools, including PCR, confocal microscopy, enzyme-linked immunosorbent assay, and immunodiffusion. When corneal scraping tests (10% KOH, Gram stain) depict fungal-like hyphae, antifungal treatments are often initiated even before culture results are ready. However, recent molecular research recommends the use of antibacterials, specifically 0.2% linezolid and 1% azithromycin, as the primary therapeutic agents. In cases that do not respond to treatment, early therapeutic keratoplasty is advised. This narrative review aims to provide a comprehensive overview of the epidemiology, clinical manifestations, laboratory and molecular diagnostic procedures, and therapeutic approaches for PIK.
... Endoglucanase and exoglucanase further produce cellobiose and cello-oligosaccharides from cellulose. Finally, β-glucosidases are used to convert cello-oligosaccharides and cellobiose into glucose monomers (Henrissat et al., 1998;Lakhundi et al., 2015). ...
In this study, purified thermo- and acid-stable cellulase from the Bacillus licheniformis was used for improving physical and sensory properties of wheat bread. The thermostable cellulase was harvested, purified and characterized from isolated B. licheniformis species. The impact of parameters such as temperature, pH, and metal ions was tested on the purified cellulase enzyme. The purified enzyme was found to be stable at pH 4.0 and also thermally stable for 6 hat 45°C. Purified cellulase was used in preparation of wheat dough followed by the preparation of baked final product wheat bread. The final baked product showed a significant decrease in hardness, adhesiveness and also chewiness. The moisture-holding capacity was significantly increased compared to control. Furthermore, the effect of cellulase in combination with amylase was also studied in preparation of bread. The improvement in sensory parameters such as volume, color, texture, aroma and taste was observed on treating the dough with a combination of cellulase and amylase.
... Endoglucanase randomly cuts cellulose chains in the amorphous region to form cello-oligosaccharides, exoglucanase act on reducing/non-reducing ends to form cellodextrins and cellobiose. Finally, β-glucosidase cleave the glycosidic linkage to form glucose (Lakhundi et al. 2015). Several bacteria and fungi can degrade cellulose through the secretion of endoglucanase-type enzymes (Watson et al. 2009). ...
Here we propose a macromolecular approach for developing a composite using collagen and functionalized bacterial cellulose (f-BC) for tissue engineering with improved cell adhesion and an acceptable degradation profile. In this study, the pure bacterial cellulose (BC) synthesized from Acetobacter xylinus using a standard Hestrin–Schramm medium has been functionalized through four different chemical routes. The successful functionalization of BC was primarily evaluated using conductometric titration, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy, X-ray diffraction, and zeta potential measurements. The nano fibrous surface morphologies of the scaffolds were confirmed using field emission scanning electron microscopy. The porosity and surface area analysis of the scaffolds were carried out using N2 adsorption–desorption using standard BET and BJH methods. Hydrophilicity, comprehensive degradation profile, and buffer uptake ability of the scaffolds were found to be satisfactory for tissue engineering applications. After a series of in vitro characterizations, f-BC treated with amine (positively charged) and f-BC treated with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (negatively charged) were further selected for composite preparation with collagen and genipin as crosslinker for potential skin and bone tissue engineering. The functionalization process was carried out merely not only to enhance the biological functions of pure BC yet also to introduce sites for grafting other biomolecules to fabricate stable composites. The enhanced cell viability efficacy and non-toxicity were further observed for the proposed f-BC/collagen composite.
... They are classified into endoglucanases and cellobiohydrolases. Endoglucanases (endo-1,4-β-glucanases, EGs) can hydrolyze internal bonds, releasing new terminal ends (ideally in amorphous cellulose areas) [5]. Cellobiohydrolases (exo-1,4-β- ...
There are many reasons that lead to the clumping of paper, such as differences in temperature and humidity, but one of the most significant factors affecting this phenomenon is the biological damage, represented by the effect of microorganisms on their constituent components. This study aimed to evaluate Aspergillus terreus RS2 cellulase as a solution to unwind the leaves and study its effect on the mechanical, physical, and chemical properties of the leaves. The study methodology relied on exposing the linen papers to artificial aging followed by natural aging to reach the agglomeration state, then dismantling the leaves using Aspergillus terreus RS2 cellulase and evaluating its effect on the paper using digital microscopy, scanning electron microscopy, measuring the mechanical properties, color change, FTIR and pH. The results proved the success of the enzyme in separating the leaves and strengthening their mechanical and natural properties. Finally, the conducted process using the produced enzyme was applied to restore and conserve a manuscript dating back to the twelfth century AD.
... It is no wonder why endophytic bacteria from DSL were able to produce the cellulolytic enzyme. Cellulase was utilized by bacteria to degrade cellulose compounds that were commonly found in wood tissue 27 . ...
Endophytic bacteria produced analogous secondary metabolites of their hosts. Similarly, the ability to generate antioxidants is not an exception. Dragon scales (Pyrrosia piloselloides), an epiphytic plant of the Polypodiaceae family, are frequently overlooked. This research aims to isolate antioxidant-producing bacteria from dragon-scale fern leaves. The antioxidant activities were tested after the extraction procedure using ethanolic extract. Bacteria were characterized and selected as candidates for antioxidant production by screening for the production of total phenolic compounds. Antioxidant levels were determined utilizing the ABTS, FRAP, and DPPH techniques. The preliminary findings of the entire phenolic compound test revealed that isolates B2, B3, C, and F produced the most phenolic compounds. The highest antioxidant activity was created by bacterial isolates B3. Bacterial isolates D1 have similar characteristics to B3 and it has been identified as Bacillus subtilis isolates D1AS. The assessment technique and extract dosages have the greatest effect on antioxidant concentration. In comparison to other approaches, the DPPH method yields considerable results when screening prospective isolates to manufacture antioxidants. Testing the ability of the results of bacterial extracts on other therapeutic effects needs to be done to ensure that the antioxidant abilities obtained in this study continue to be developed.
... However, it is not clear where chitin exists in ectocyst or endocyst. Cellulose is basically a straight chain polymer of β-1, 4 linked D-glucose units which are arranged in alternate orientation with respect to one another (Béguin and Aubert, 1994;Lakhundi et al., 2015). It is with no coiling and rod-like conformation that provokes spontaneous crystallization of the molecule (Schwarz, 2001). ...
Acanthamoeba is an opportunistic protozoa, which exists widely in nature and is mainly distributed in soil and water. Acanthamoeba usually exists in two forms, trophozoites and cysts. The trophozoite stage is one of growth and reproduction while the cyst stage is characterized by cellular quiescence, commonly resulting in human infection, and the lack of effective monotherapy after initial infection leads to chronic disease. Acanthamoeba can infect several human body tissues such as the skin, cornea, conjunctiva, respiratory tract, and reproductive tract, especially when the tissue barriers are damaged. Furthermore, serious infections can cause Acanthamoeba keratitis, granulomatous amoebic encephalitis, skin, and lung infections. With an increasing number of Acanthamoeba infections in recent years, the pathogenicity of Acanthamoeba is becoming more relevant to mainstream clinical care. This review article will describe the etiological characteristics of Acanthamoeba infection in detail from the aspects of biological characteristic, classification, disease, and pathogenic mechanism in order to provide scientific basis for the diagnosis, treatment, and prevention of Acanthamoeba infection.
... The unique properties of cellulose are a result of its unique structure. Cellulose is a crystalline solid that is hydrophilic and biodegradable [2]. Cellulose is a massive renewable bioresource synthesized by a photosynthetic process. ...
Objective: The green plant waste consists of a high amount of lignocellulosic materials offering an intense environment for the growth of cellulolytic bacteria, which have ability to degrade plant biomass as a carbon source. This cellulase produced can be used to break down plant waste into valuable products such as monomeric sugars, biofuels, compost etc. Therefore, the aim of present study was to isolate and identify potent cellulose-degrading bacteria from decomposing plant matter and assessment of their cellulolytic activity. Methods: The cellulolytic bacteria were isolated by serial dilution technique on CMC agar media and six isolates were selected based on their cellulose hydrolysing ability. Based on the biochemical tests such as Oxidase test, Voges-Proskauer test, Methyl red test, Catalase test and sequence analysis of 16s rRNA genes. Results: The isolates were identified as Paenibacillus alvei, Paenibacillus lentimorbus, Bacillus subtilis, Bacillus nakamurai with percentage identity of 93.77%, 92.80%, 97.71% and 91.94%, respectively, as obtained from NCBI BLAST. Among these Paenibacillus alvei showed the highest cellulase activity. Conclusion: The findings of this study could pave the way for the use of cellulose as an inexpensive energy source for bacteria that are capable of producing valuable products.
... It has a crystalline structure formed of linear polymer units which in turn form microfibrils held together by hydrogen bonds, forming cellulose fibres which provide tensile strength. However, there is also a varying extent of amorphinity in structure, with enough heterogeneity in topology to allow susceptibility to cellulase -enzymes which can be produced by fungi which decompose cellulose molecules with the mechanism of hydrolysis [30]. Fungi harbour enzymes which break down cellulose into simpler forms (mostly glucose) [31]. ...
Fibrous plaster degradation has been a key concern over recent years, with ceiling failures occurring suddenly in historic buildings, including the Apollo theatre in 2013. This rigorous investigation explores fibrous plaster degradation through subjecting 290 specimens to a range of moisture and fungal-related treatment conditions over periods of up to two years and analysis using mechanical flexural tests, Fourier Transform Infrared Spec-troscopy (FTIR), Scanning Electron Microscopy (SEM) and Deoxyribonucleic Acid (DNA) sequencing. Using FTIR peak ratios from spectra of hessian fibres and mechanical tests in conjunction, an original methodology for identifying mechanisms and severity of fibrous plaster degradation through moisture and fungal exposure was developed. Results showed defined clusters for differing moisture and fungal treatments when two peak ratios are plotted together and compared with mechanical data. Fungal exposure over two years, water submersion and wetting and drying were particularly detrimental conditions for fibrous plaster. Fungal exposure resulted in degradation of cellulose bonds in hessian fibres, with defined clusters on the extreme left of peak ratio plots correlating with a pronounced reduction in fibrous plaster mean flexural strength of 51%. Fungal species Peni-cillium and Chaetomium were identified on test samples. Moisture affected plaster matrices significantly with wetting/drying and water submersion treatments resulting in a 71% reduction in mean flexural strength for unreinforced plaster, reducing to 26% with hessian-reinforced fibrous plaster. Many buildings containing fibrous plaster are listed and removal of material is often minimised-the high impact of this research stems from the ability to rapidly assess the mechanical integrity of a very small quantity of harvested historic hessian fibres using FTIR. Identifying the location of weakened fibres in a ceiling is highly important for effective restoration and conservation.
... The degradation of cellulose can be carried out by the enzymes called "cellulases" which is responsible for the hydrolysis of beta-1,4-linkages present in the cellulose [45]. Cellulose is hydrolyzed by a variety of simultaneously acting enzymes which interacts each other to bring complete hydrolysis. ...
Biodegradable polymers have emerged as fascinating materials due to their non-toxicity, environmentally benign nature and good mechanical strength. The toxic effects of non-biodegradable plastics paved way for the development of sustainable and biodegradable polymers. The engineering of biodegradable polymers employing various strategies like radical ring opening polymerization, enzymatic ring opening polymerization, anionic ring opening polymerization, photo-initiated radical polymerization, chemoenzymatic method, enzymatic polymerization, ring opening polymerization and coordinative ring opening polymerization have been discussed in this review. The application of biodegradable polymeric nanoparticles in the biomedical field and cosmetic industry is considered to be an emerging field of interest. However, this review mainly highlights the applications of selected biodegradable polymers like polylactic acid, poly(ε-caprolactone), polyethylene glycol, polyhydroxyalkanoates, poly(lactide-co-glycolide) and polytrimethyl carbonate in various fields like agriculture, biomedical, biosensing, food packaging, automobiles, wastewater treatment, textile and hygiene, cosmetics and electronic devices.
