scholarly journals Anticandidal Potential of Two Cyanobacteria-Synthesized Silver Nanoparticles: Effects on Growth, Cell Morphology, and Key Virulence Attributes of Candida albicans

Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1688
Author(s):  
Reham Samir Hamida ◽  
Mohamed Abdelaal Ali ◽  
Doaa A. Goda ◽  
Alya Redhwan
Keyword(s):  
Gene Expression ◽  
Silver Nanoparticles ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Cell Envelope ◽  
Membrane Integrity ◽  
Ultrastructural Changes ◽  
Protein Patterns ◽  
Antimicrobial Drugs ◽  
Fungal Cell

Candida albicans is an opportunistic human fungal pathogen responsible for 90–100% of mucosal and nosocomial infections worldwide. The emergence of drug-resistant strains has resulted in adverse consequences for human health, including numerous deaths. Consequently, there is an urgent need to identify and develop new antimicrobial drugs to counter these effects. Antimicrobial nanoagents have shown potent inhibitory activity against a number of pathogens through targeting their defense systems, such as biofilm formation. Here, we investigated the anticandidal activity of silver nanoparticles biosynthesized by the cyanobacterial strains Desertifilum sp. IPPAS B-1220 and Nostoc Bahar_M (D-SNPs and N-SNPs, respectively), along with that of silver nitrate (AgNO3), and examined the mechanisms underlying their lethal effects. For this, we performed agar well diffusion and enzyme activity assays (lactate dehydrogenase, adenosine triphosphatase, glutathione peroxidase, and catalase) and undertook morphological examinations using transmission electron microscopy. The effects of the three treatments on Hwp1 and CDR1 gene expression and protein patterns were assessed using qRT-PCR and SDS–PAGE assays, respectively. All of the three treatments inhibited C. albicans growth; disrupted membrane integrity, metabolic function, and antioxidant activity; induced ultrastructural changes in the cell envelope; and disrupted cytoplasmic and nuclear contents. Of the three agents, D-SNPs showed the greatest biocidal activity against C. albicans. Additionally, the D-SNP treatment significantly reduced the gene expression of Hwp1 and CDR1, suggestive of negative effects on biofilm formation ability and resistance potential of C. albicans, and promoted protein degradation. The mechanism involved in the biocidal effects of both D-SNPs and N-SNPs against C. albicans could be attributed to their ability to interfere with fungal cell structures and/or stimulate oxidative stress, enabling them to be used as a robust antimycotic agent.

scholarly journals Counteraction of Biofilm Formation and Antimicrobial Potential of Terminalia catappa Functionalized Silver Nanoparticles against Candida albicans and Multidrug-Resistant Gram-Negative and Gram-Positive Bacteria

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 725
Author(s):  
Mohammad Azam Ansari ◽  
Abul Kalam ◽  
Abdullah G. Al-Sehemi ◽  
Mohammad N. Alomary ◽  
Sami AlYahya ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Cell Wall ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Membrane Integrity ◽  
Multidrug Resistant ◽  
Ultrastructural Changes ◽  
Resistant Bacteria ◽  
Terminalia Catappa

Biofilms not only protect bacteria and Candida species from antibiotics, but they also promote the emergence of drug-resistant strains, making eradication more challenging. As a result, novel antimicrobial agents to counteract biofilm formation are desperately needed. In this study, Terminalia catappa leaf extract (TCE) was used to optimize the TCE-capped silver nanoparticles (TCE-AgNPs) via a one-pot single-step method. Varied concentrations of TCE have yielded different sized AgNPs. The physico-chemical characterization of TCE-AgNPs using UV-Vis, SEM, TEM, FTIR, and Raman spectroscopy have confirmed the formation of nanostructures, their shape and size and plausible role of TCE bio-active compounds, most likely involved in the synthesis as well as stabilization of NPs, respectively. TCE-AgNPs have been tested for antibiofilm and antimicrobial activity against multidrug-resistant Pseudomonas aeruginosa (MDR-PA), methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans using various microbiological protocols. TCE-Ag-NPs−3 significantly inhibits biofilm formation of MDR-PA, MRSA, and C. albicans by 73.7, 69.56, and 63.63%, respectively, at a concentration of 7.8 µg/mL, as determined by crystal violet microtiter assay. Furthermore, SEM micrograph shows that TCE-AgNPs significantly inhibit the colonization and adherence of biofilm forming cells; individual cells with loss of cell wall and membrane integrity were also observed, suggesting that the biofilm architecture and EPS matrix were severely damaged. Moreover, TEM and SEM images showed that TCE-AgNPs brutally damaged the cell wall and membranes of MDR-PA, MRSA, and C. albicans. Additionally, extreme ultrastructural changes such as deformation, disintegration, and separation of cell wall and membrane from the cells, have also been observed, indicating significant loss of membrane and cell wall integrity, which eventually led to cell death. Overall, the research revealed a simple, environmentally friendly, and low-cost method for producing colloidal TCE-AgNPs with promising applications in advanced clinical settings against broad-spectrum biofilm-forming antibiotic-resistant bacteria and candida strains.

scholarly journals In Fungal Intracellular Pathogenesis, Form Determines Fate

mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Robin C. May ◽  
Arturo Casadevall
Keyword(s):  
Candida Albicans ◽  
Fungal Pathogen ◽  
Membrane Integrity ◽  
Pathogenic Fungi ◽  
Morphological Transition ◽  
Physical Damage ◽  
Fungal Cell ◽  
Morphological Transitions ◽  
Pathogenic Microbes ◽  
Phagosomal Membrane

ABSTRACT For pathogenic microbes to survive ingestion by macrophages, they must subvert powerful microbicidal mechanisms within the phagolysosome. After ingestion, Candida albicans undergoes a morphological transition producing hyphae, while the surrounding phagosome exhibits a loss of phagosomal acidity. However, how these two events are related has remained enigmatic. Now Westman et al. (mBio 9:e01226-18, 2018, https://doi.org/10.1128/mBio.01226-18) report that phagosomal neutralization results from disruption of phagosomal membrane integrity by the enlarging hyphae, directly implicating the morphological transition in physical damage that promotes intracellular survival. The C. albicans intracellular strategy shows parallels with another fungal pathogen, Cryptococcus neoformans, where a morphological changed involving capsular enlargement intracellularly is associated with loss of membrane integrity and death of the host cell. These similarities among distantly related pathogenic fungi suggest that morphological transitions that are common in fungi directly affect the outcome of the fungal cell-macrophage interaction. For this class of organisms, form determines fate in the intracellular environment.

scholarly journals Spatial Distribution of a Porphyrin-Based Photosensitizer Reveals Mechanism of Photodynamic Inactivation of Candida albicans

2021 ◽  
Vol 8 ◽  
Author(s):  
Thomas Voit ◽  
Fabian Cieplik ◽  
Johannes Regensburger ◽  
Karl-Anton Hiller ◽  
Anita Gollmer ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Fungal Infections ◽  
Cell Envelope ◽  
Antimicrobial Photodynamic Therapy ◽  
Fungal Cell ◽  
Before And After ◽  
Antifungal Action ◽  
Complete Cell ◽  
Further Development

The antimicrobial photodynamic therapy (aPDT) is a promising approach for the control of microbial and especially fungal infections such as mucosal mycosis. TMPyP [5,10,15, 20-tetrakis(1-methylpyridinium-4-yl)-porphyrin tetra p-toluenesulfonate] is an effective photosensitizer (PS) that is commonly used in aPDT. The aim of this study was to examine the localization of TMPyP in Candida albicans before and after irradiation with visible light to get information about the cellular mechanism of antifungal action of the photodynamic process using this PS. Immediately after incubation of C. albicans with TMPyP, fluorescence microscopy revealed an accumulation of the PS in the cell envelope. After irradiation with blue light the complete cell showed red fluorescence, which indicates, that aPDT is leading to a damage in the cell wall with following influx of PS into the cytosol. Incubation of C. albicans with Wheat Germ Agglutinin (WGA) could confirm the cell wall as primary binding site of TMPyP. The finding that the porphyrin accumulates in the fungal cell wall and does not enter the interior of the cell before irradiation makes it unlikely that resistances can emerge upon aPDT. The results of this study may help in further development and modification of PS in order to increase efficacy against fungal infections such as those caused by C. albicans.

scholarly journals Temporal Profile of Biofilm Formation, Gene Expression and Virulence Analysis in Candida albicans Strains

2016 ◽  
Vol 182 (3-4) ◽  
pp. 285-295 ◽  
Author(s):  
Patrícia Pimentel de Barros ◽  
Rodnei Dennis Rossoni ◽  
Felipe De Camargo Ribeiro ◽  
Juliana Campos Junqueira ◽  
Antonio Olavo Cardoso Jorge
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Temporal Profile ◽  
Virulence Analysis

scholarly journals Cell Envelope Perturbation Induces Oxidative Stress and Changes in Iron Homeostasis in Vibrio cholerae

2009 ◽  
Vol 191 (17) ◽  
pp. 5398-5408 ◽  
Author(s):  
Aleksandra E. Sikora ◽  
Sinem Beyhan ◽  
Michael Bagdasarian ◽  
Fitnat H. Yildiz ◽  
Maria Sandkvist
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Outer Membrane ◽  
Vibrio Cholerae ◽  
Iron Homeostasis ◽  
Cell Envelope ◽  
Membrane Integrity ◽  
Genetic Alterations ◽  
Iron Storage ◽  
Study Gene Expression

ABSTRACT The Vibrio cholerae type II secretion (T2S) machinery is a multiprotein complex that spans the cell envelope. When the T2S system is inactivated, cholera toxin and other exoproteins accumulate in the periplasmic compartment. Additionally, loss of secretion via the T2S system leads to a reduced growth rate, compromised outer membrane integrity, and induction of the extracytoplasmic stress factor RpoE (A. E. Sikora, S. R. Lybarger, and M. Sandkvist, J. Bacteriol. 189:8484-8495, 2007). In this study, gene expression profiling reveals that inactivation of the T2S system alters the expression of genes encoding cell envelope components and proteins involved in central metabolism, chemotaxis, motility, oxidative stress, and iron storage and acquisition. Consistent with the gene expression data, molecular and biochemical analyses indicate that the T2S mutants suffer from internal oxidative stress and increased levels of intracellular ferrous iron. By using a tolA mutant of V. cholerae that shares a similar compromised membrane phenotype but maintains a functional T2S machinery, we show that the formation of radical oxygen species, induction of oxidative stress, and changes in iron physiology are likely general responses to cell envelope damage and are not unique to T2S mutants. Finally, we demonstrate that disruption of the V. cholerae cell envelope by chemical treatment with polymyxin B similarly results in induction of the RpoE-mediated stress response, increased sensitivity to oxidants, and a change in iron metabolism. We propose that many types of extracytoplasmic stresses, caused either by genetic alterations of outer membrane constituents or by chemical or physical damage to the cell envelope, induce common signaling pathways that ultimately lead to internal oxidative stress and misregulation of iron homeostasis.

scholarly journals Facile and Eco-Friendly Fabrication of Silver Nanoparticles Using Nyctanthes arbor-tristis Leaf Extract to Study Antibiofilm and Anticancer Properties against Candida albicans

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Beema Shafreen Rajamohamed ◽  
Seema Siddharthan ◽  
Velmurugan Palanivel ◽  
Mohanavel Vinayagam ◽  
Vijayanand Selvaraj ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Leaf Extract ◽  
Morphological Changes ◽  
Spherical Shape ◽  
Toxic Chemicals ◽  
X Ray ◽  
Anticancer Properties ◽  
Color Visualization

The synthesis of silver nanoparticles has been gaining more attention in recent years due to their small size and high stability. For this study, silver nanoparticles were biosynthesized from leaf extract of the medicinal plant (N. arbor-tristis). Vitally, the shrub with tremendous medicinal usage was diversely observed in South Asia and South East Asia. The synthesized silver nanoparticles were characterized by color visualization, ultraviolet-visible spectrophotometry (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), field emission-scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and dynamic light scattering (DLS) technique. A sharp peak at 427 nm for biosynthesized nanoparticles was obtained using UV-Vis, which represents surface plasmon resonance. Thus, characterization techniques showed the green synthesis of AgNPs leads to the fabrication of spherical shape particles with a size of 67 nm. Furthermore, AgNPs were subjected to antibiofilm studies against Candida albicans and it was observed that 0.5 μg mL−1 of AgNPs significantly reduced 50% of biofilm formation. These biosynthesized nanoparticles also showed a considerable reduction in viability of HeLa cells at 0.5 μg mL−1. The morphological changes induced by AgNPs were observed by AO/EB staining. The toxic effect of AgNPs was studied using brine shrimp as a model system. Therefore, it is envisaged that further investigation with these AgNPs can replace toxic chemicals, assist in the development of biomedical implants that can prevent biofilm formation, and avoid infections due to C. albicans.

scholarly journals Antifungal and Antibiofilm Activities and the Mechanism of Action of Repeating Lysine-Tryptophan Peptides against Candida albicans

2020 ◽  
Vol 8 (5) ◽  
pp. 758
Author(s):  
Gopal Ramamourthy ◽  
Jonggwan Park ◽  
Changho Seo ◽  
Hans J. Vogel ◽  
Yoonkyung Park
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Laser Scanning ◽  
Membrane Integrity ◽  
Laser Scanning Confocal Microscopy ◽  
Health Concern ◽  
Cellular Functions ◽  
Fungal Cell ◽  
Scanning Confocal Microscopy ◽  
Keratinocyte Cell

The rapid increase in the emergence of antifungal-resistant Candida albicans strains is becoming a serious health concern. Because antimicrobial peptides (AMPs) may provide a potential alternative to conventional antifungal agents, we have synthesized a series of peptides with a varying number of lysine and tryptophan repeats (KWn-NH2). The antifungal activity of these peptides increased with peptide length, but only the longest KW5 peptide displayed cytotoxicity towards a human keratinocyte cell line. The KW4 and KW5 peptides exhibited strong antifungal activity against C. albicans, even under conditions of high-salt and acidic pH, or the addition of fungal cell wall components. Moreover, KW4 inhibited biofilm formation by a fluconazole-resistant C. albicans strain. Circular dichroism and fluorescence spectroscopy indicated that fungal liposomes could interact with the longer peptides but that they did not release the fluorescent dye calcein. Subsequently, fluorescence assays with different dyes revealed that KW4 did not disrupt the membrane integrity of intact fungal cells. Scanning electron microscopy showed no changes in fungal morphology, while laser-scanning confocal microscopy indicated that KW4 can localize into the cytosol of C. albicans. Gel retardation assays revealed that KW4 can bind to fungal RNA as a potential intracellular target. Taken together, our data indicate that KW4 can inhibit cellular functions by binding to RNA and DNA after it has been translocated into the cell, resulting in the eradication of C. albicans.

scholarly journals Evaluation of Candida albicans adhesion and biofilm formation on a denture base acrylic resin containing silver nanoparticles

2012 ◽  
Vol 112 (6) ◽  
pp. 1163-1172 ◽  
Author(s):  
A.F. Wady ◽  
A.L. Machado ◽  
V. Zucolotto ◽  
C.A. Zamperini ◽  
E. Berni ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Acrylic Resin ◽  
Denture Base

scholarly journals Antifungal Activity of Mammalian Serum Amyloid A1 against Candida albicans

2019 ◽  
Vol 64 (1) ◽  
Author(s):  
Jiao Gong ◽  
Jun Wu ◽  
Melanie Ikeh ◽  
Li Tao ◽  
Yulong Zhang ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Membrane Integrity ◽  
Systemic Infection ◽  
Serum Amyloid ◽  
Infection Model ◽  
Fungal Cell ◽  
Content Type ◽  
Cell Membrane Integrity ◽  
Amyloid A

ABSTRACT Mammalian serum amyloid A (SAA) is a major acute phase protein that shows a massive increase in plasma concentration during inflammation. In the present study, we demonstrate that the expression of mouse SAA1 in serum was increased when infected with Candida albicans, a major human fungal pathogen, in a systemic infection model. We then set out to investigate the antifungal activity of SAA proteins against C. albicans. Recombinant human and mouse SAA1 (rhSAA1 and rmSAA1) were expressed and purified in Escherichia coli. Both rhSAA1 and rmSAA1 exhibited a potent antifungal activity against C. albicans. We further demonstrate that rhSAA1 binds to the cell surface of C. albicans, disrupts cell membrane integrity, and induces rapid fungal cell death in C. albicans. Our finding expands the known functions of SAA1 and provides new insight into host-Candida interactions during fungal infection.

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