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1.
RSC Adv ; 14(29): 21190-21202, 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38966810

ABSTRACT

Candida auris, a recent addition to the Candida species, poses a significant threat with its association to numerous hospital outbreaks globally, particularly affecting immunocompromised individuals. Given its resistance to existing antifungal therapies, there is a pressing need for innovative treatments. In this study, novel triazole bridged quinoline derivatives were synthesized and evaluated for their antifungal activity against C. auris. The most promising compound, QT7, demonstrated exceptional efficacy with a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 0.12 µg mL-1 and 0.24 µg mL-1, respectively. Additionally, QT7 effectively disrupted mature biofilms, inhibiting them by 81.98% ± 8.51 and 89.57 ± 5.47 at MFC and 2× MFC values, respectively. Furthermore, QT7 induced cellular apoptosis in a dose-dependent manner, supported by various apoptotic markers such as phosphatidylserine externalization, mitochondrial depolarization, and reduced cytochrome c and oxidase activity. Importantly, QT7 exhibited low hemolytic activity, highlighting its potential for further investigation. Additionally, the physicochemical properties of this compound suggest its potential as a lead drug candidate, warranting further exploration in drug discovery efforts against Candida auris infections.

2.
Int J Lab Hematol ; 2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38874199

ABSTRACT

INTRODUCTION: Current molecular research has shown the several oncogenic pathways that give rise to the peripheral T-cell lymphoma, not otherwise defined (PTCL, NOS) subtypes, which alter prognosis and might have predictive value. This study was conducted to assess the immunohistochemistry (IHC) algorithm by Amador et al for the subtyping of PTCL, NOS and determine its applicability in relation to the clinicopathological profile. METHODS: This study included 43 patients with PTCL, NOS diagnosis. Following the use of IHC for the transcription factors GATA3, TBX21, CCR4, and CXCR3, two pathologists subtyped the samples. Comprehensive clinicopathological correlation was carried out. RESULTS: Applying the algorithm of Amador et al., cases were classified into GATA3 (20), TBX21 (15), and unclassified (8) subtypes. No significant association with clinical parameters of subtypes or CD4/ CD8 positivity was observed. Although a higher proportion of cases in the TBX21 subgroup showed a polymorphic population compared with the GATA3 subgroup, which had a monomorphic population, no significant p-value (0.111) was observed. Two Lennert lymphomas were classified into the GATA3 subgroup. Multivariate analysis showed no significant difference in overall survival (p-value = 0.105) and progression-free survival (p-value = 0.0509) between IHC-defined subtypes; trends indicate that overall survival and progression-free survival are worse in the GATA3 subgroup. CONCLUSION: Although the algorithm is reproducible, a proportion of cases remains unclassifiable and may require additional investigation and gene expression profiling. The GATA3 subgroup was found to have a monomorphic population with a poor overall prognosis and thus requires a larger sample size for validation.

3.
Dalton Trans ; 53(28): 11720-11735, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-38932585

ABSTRACT

Heteroleptic metal complexes containing CuII, CoII, and ZnII, incorporating curcumin and a Schiff base ligand (L), were synthesized and characterized, and their antifungal activity was evaluated. Their antifungal activities were investigated individually and in combination with fluconazole. Utilizing various analytical techniques such as UV-Vis, FT-IR, NMR, ESI-MS, TGA-DTG, elemental analyses, conductance, and magnetic susceptibility measurements, complex C1 ([Cu(Cur)LCl(H2O)]) was assigned a distorted octahedral geometry, while complexes C2 ([Co(Cur)LCl(H2O)]) and C3 ([Zn(Cur)LCl(H2O)]) were assigned octahedral geometries. Among these complexes, C2 exhibited the highest inhibitory activity against both FLC-susceptible and resistant strains of Candida albicans. Furthermore, C2 demonstrated candidicidal activity and synergistic interactions with fluconazole, effectively inhibiting the growth and survival of both FLC-resistant and FLC-sensitive C. albicans strains. The complex displayed a dose-dependent inhibition of drug efflux pumps in FLC-resistant C. albicans strains, indicating its potential to disrupt the cell membrane of these strains. The significant role of membrane efflux transporters in the development of antifungal drug resistance within Candida species has been extensively documented and our findings indicate that complex C2 specifically targets this crucial factor, thereby playing a pivotal role in mitigating drug resistance in C. albicans.


Subject(s)
Antifungal Agents , Candida albicans , Cell Membrane , Cobalt , Coordination Complexes , Fluconazole , Microbial Sensitivity Tests , Fluconazole/pharmacology , Antifungal Agents/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/chemical synthesis , Candida albicans/drug effects , Cobalt/chemistry , Cobalt/pharmacology , Coordination Complexes/pharmacology , Coordination Complexes/chemistry , Coordination Complexes/chemical synthesis , Cell Membrane/drug effects , Drug Synergism , Drug Resistance, Fungal/drug effects
4.
J Med Microbiol ; 73(5)2024 May.
Article in English | MEDLINE | ID: mdl-38743468

ABSTRACT

Introduction. Innovative antifungal therapies are of crucial importance to combat the potentially life-threatening infections linked to the multidrug-resistant fungal pathogen Candida auris. Induction of regulated cell death, apoptosis, could provide an outline for future therapeutics. Human antimicrobial peptides (AMPs), well-known antifungal compounds, have shown the ability to induce apoptosis in pathogenic fungi.Hypothesis/Gap Statement . Although it is known that AMPs possess antifungal activity against C. auris, their ability to induce apoptosis requires further investigations.Aim. This study evaluated the effects of AMPs on the induction of apoptosis in C. auris.Methods. Human neutrophil peptide-1 (HNP-1), human ß-Defensins-3 (hBD-3) and human salivary histatin 5 (His 5) were assessed against two clinical C. auris isolates. Apoptosis hallmarks were examined using FITC-Annexin V/PI double labelling assay and terminal deoxynucleotidyl transferase deoxynucleotidyl transferase nick-end labelling (TUNEL) to detect phosphatidylserine externalization and DNA fragmentation, respectively. Then, several intracellular triggers were studied using JC-10 staining, spectrophotometric assay and 2',7'-dichlorofluorescin diacetate staining to measure the mitochondrial membrane potential, cytochrome-c release and reactive oxygen species (ROS) production, respectively.Results and conclusion. FITC-Annexin V/PI staining and TUNEL analysis revealed that exposure of C. auris cells to HNP-1 and hBD-3 triggered both early and late apoptosis, while His 5 caused significant necrosis. Furthermore, HNP-1 and hBD-3 induced significant mitochondrial membrane depolarization, which resulted in substantial cytochrome c release. In contrast to His 5, which showed minimal mitochondrial depolarization and no cytochrome c release. At last, all peptides significantly increased ROS production, which is related to both types of cell death. Therefore, these peptides represent promising and effective antifungal agents for treating invasive infections caused by multidrug-resistant C. auris.


Subject(s)
Antifungal Agents , Apoptosis , Candida auris , Histatins , Reactive Oxygen Species , Apoptosis/drug effects , Humans , Antifungal Agents/pharmacology , Histatins/pharmacology , Reactive Oxygen Species/metabolism , Candida auris/drug effects , beta-Defensins/pharmacology , Membrane Potential, Mitochondrial/drug effects , alpha-Defensins/pharmacology , Microbial Sensitivity Tests , Antimicrobial Peptides/pharmacology , Antimicrobial Peptides/chemistry , Cytochromes c/metabolism , DNA Fragmentation/drug effects , Candidiasis/drug therapy , Candidiasis/microbiology
5.
Int J Biol Macromol ; 271(Pt 1): 132719, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38821810

ABSTRACT

Natural products have a long history of success in treating bacterial infections, making them a promising source for novel antibacterial medications. Curcumin, an essential component of turmeric, has shown potential in treating bacterial infections and in this study, we covalently immobilized curcumin (Cur) onto chitosan (CS) using glutaraldehyde and tannic acid (TA), resulting in the fabrication of novel biocomposites with varying CS/Cur/TA ratios. Comprehensive characterization of these ternary biocomposites was conducted using FTIR, SEM, XPS, and XRD to assess their morphology, functional groups, and chemical structures. The inhibitory efficacy of these novel biocomposites (n = 4) against the growth and viability of Pseudomonas aeruginosa (ATCC27853) and Chromobacterium violaceum (ATCC12472) was evaluated and the most promising composite (C3) was investigated for its impact on quorum sensing (QS) and biofilm formation in these bacteria. Remarkably, this biocomposite significantly disrupted QS circuits and effectively curtailed biofilm formation in the tested pathogens without inducing appreciable toxicity. These findings underscore its potential for future in vivo studies, positioning it as a promising candidate for the development of biofilm disrupting antibacterial agents.


Subject(s)
Anti-Bacterial Agents , Biofilms , Chitosan , Curcumin , Pseudomonas aeruginosa , Quorum Sensing , Tannins , Chitosan/chemistry , Chitosan/pharmacology , Quorum Sensing/drug effects , Biofilms/drug effects , Biofilms/growth & development , Curcumin/pharmacology , Curcumin/chemistry , Tannins/chemistry , Tannins/pharmacology , Pseudomonas aeruginosa/drug effects , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Chromobacterium/drug effects , Microbial Sensitivity Tests , Polyphenols
6.
Heliyon ; 10(9): e29967, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38694063

ABSTRACT

The COVID-19 pandemic has become a significant global issue in terms of public health. While it is largely associated with respiratory complications, recent reports indicate that patients also experience neurological symptoms and other health issues. The objective of this study is to examine the network of protein-protein interactions (PPI) between SARS-CoV-2 proteins and human host proteins, pinpoint the central genes within this network implicated in disease pathology, and assess their viability as targets for drug development. The study adopts a network-based approach to construct a network of 29 SARS-CoV-2 proteins interacting with 2896 host proteins, with 176 host genes being identified as interacting genes with all the viral proteins. Gene ontology and pathway analysis of these host proteins revealed their role in biological processes such as translation, mRNA splicing, and ribosomal pathways. We further identified EEF2, RPS3, RPL9, RPS16, and RPL11 as the top 5 most connected hub genes in the disease-causing network, with significant interactions among each other. These hub genes were found to be involved in ribosomal pathways and cytoplasmic translation. Further a disease-gene interaction was also prepared to investigate the role of hub genes in other disorders and to understand the condition of comorbidity in COVID-19 patients. We also identified 13 drug molecules having interactions with all the hub genes, and estradiol emerged as the top potential drug target for the COVID-19 patients. Our study provides valuable insights using the protein-protein interaction network of SARS-CoV-2 proteins with host proteins and highlights the molecular basis of manifestation of COVID-19 and proposes drug for repurposing. As the pandemic continues to evolve, it is anticipated that investigating SARS-CoV-2 proteins will remain a critical area of focus for researchers globally, particularly in addressing potential challenges posed by specific SARS-CoV-2 variants in the future.

7.
Microorganisms ; 12(3)2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38543629

ABSTRACT

Viruses are minuscule infectious agents that reproduce exclusively within the living cells of an organism and are present in almost every ecosystem. Their continuous interaction with humans poses a significant threat to the survival and well-being of everyone. Apart from the common cold or seasonal influenza, viruses are also responsible for several important diseases such as polio, rabies, smallpox, and most recently COVID-19. Besides the loss of life and long-term health-related issues, clinical viral infections have significant economic and social impacts. Viral enzymes, especially proteases which are essential for viral multiplication, represent attractive drug targets. As a result, screening of viral protease inhibitors has gained a lot of interest in the development of anti-viral drugs. Despite the availability of anti-viral therapeutics, there is a clear need to develop novel curative agents that can be used against a given virus or group of related viruses. This review highlights the importance of yeasts as an in vivo model for screening viral enzyme inhibitors. We also discuss the advantages of yeast-based screening platforms over traditional assays. Therefore, in the present article, we discuss why yeast is emerging as a model of choice for in vivo screening of anti-viral molecules and why yeast-based screening will become more relevant in the future for screening anti-viral and other molecules of clinical importance.

8.
J Cancer Res Ther ; 20(1): 268-274, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-38554332

ABSTRACT

BACKGROUND: Aberrant crypt foci (ACF) are the earliest preneoplastic lesions in human colon, identifiable on chromoendoscopic screening. Our objective was to evaluate the %methylation of APC, CDKN2A, MLH1, RASSF1, MGMT, and WIF1 tumor suppressor genes (TSG) in ACF, corresponding colorectal carcinomas (CRC), and normal colonic mucosal controls. METHODS: In this study, macroscopically normal-appearing mucosal flaps were sampled 5-10 cm away from the tumor mass from 302 fresh colectomy specimens to identify ACF-like lesions. Thirty-five cases with multiple ACFs were selected (n 35) as the main study group, with corresponding sections from CRC (n 35) as disease controls, and mucosal tissue blocks from 20 colectomy specimens (normal controls), operated for non-neoplastic pathologies. Genomic DNA was extracted, and methylation-specific polymerase chain reaction (PCR) was performed on a customized methylation array model. %Methylation data were compared among the groups and with clinicopathological parameters. Selected target mRNA and protein expression studies were performed. RESULTS: %Methylation of TSGs in ACF was intermediate between normal colon and CRC, although a statistically significant difference was observed only for the WIF1 gene (P < 0.01). Also, there was increased nuclear ß-catenin expression and upregulation of CD44-positive cancer-stem cells in ACF and CRCs than in controls. Right-sided ACFs and dysplastic ACFs had a higher %methylation of CDKN2A (P < 0.01), whereas hyperplastic ACFs had a higher %methylation of RASSF1 (P 0.04). The topographic characteristics of ACFs did not correlate with TSG %methylation. CONCLUSIONS: Early epigenetic methylation of WIF1 gene is one of the mechanisms for ACF development in human colon.


Subject(s)
Aberrant Crypt Foci , Colonic Neoplasms , Colorectal Neoplasms , Precancerous Conditions , Humans , Aberrant Crypt Foci/genetics , Aberrant Crypt Foci/diagnosis , Aberrant Crypt Foci/pathology , Colorectal Neoplasms/pathology , Colon/pathology , Hyperplasia/pathology , Methylation , Genes, Tumor Suppressor , Precancerous Conditions/pathology , Colonic Neoplasms/pathology , Intestinal Mucosa/pathology
9.
PLoS One ; 18(6): e0285473, 2023.
Article in English | MEDLINE | ID: mdl-37343020

ABSTRACT

Candida auris, the youngest Candida species, is known to cause candidiasis and candidemia in humans and has been related to several hospital outbreaks. Moreover, Candida auris infections are largely resistant to the antifungal drugs currently in clinical use, necessitating the development of novel medications and approaches to treat such infections. Following up on our previous studies that demonstrated eugenol tosylate congeners (ETCs) to have antifungal activity, several ETCs (C1-C6) were synthesized to find a lead molecule with the requisite antifungal activity against C. auris. Preliminary tests, including broth microdilution and the MUSE cell viability assay, identified C5 as the most active derivative, with a MIC value of 0.98 g/mL against all strains tested. Cell count and viability assays further validated the fungicidal activity of C5. Apoptotic indicators, such as phosphatidylserine externalization, DNA fragmentation, mitochondrial depolarization, decreased cytochrome c and oxidase activity and cell death confirmed that C5 caused apoptosis in C. auris isolates. The low cytotoxicity of C5 further confirmed the safety of using this derivative in future studies. To support the conclusions drawn in this investigation, additional in vivo experiments demonstrating the antifungal activity of this lead compound in animal models will be needed.


Subject(s)
Antifungal Agents , Candidiasis, Invasive , Animals , Humans , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Candida auris , Eugenol/pharmacology , Microbial Sensitivity Tests , Apoptosis , Candidiasis, Invasive/drug therapy , Cell Cycle Checkpoints
10.
Microbiol Spectr ; 11(4): e0362322, 2023 08 17.
Article in English | MEDLINE | ID: mdl-37338400

ABSTRACT

Most investigations into the distribution of methicillin resistant Staphylococcus aureus (MRSA) have focused exclusively on bloodborne infections within individual health care institutions for shorter time periods. This has limited the analysis of a community-spread pathogen to snapshots within the hospital domain. Therefore, in this study we determined the demographic and geographical patterns of MRSA infections and their fluctuation in 10 years within all public hospitals in Gauteng, South Africa. A retrospective analysis of S. aureus samples was done by deduplicating samples in two groups. The sample groups were placed into subsets with respect to demographic and geographical fields and compared across the studied period. Logistic regression was utilized to determine odds ratios for resistant infections in univariate and multivariable configurations. A total of 66,071 unique infectious events were identified from the 148,065 samples received over a 10-year period, out of which 14,356 were identified as bacteremia. MRSA bacteremia rates in Gauteng peaked in 2015 and have since decreased. Within Gauteng, metropolitan areas have the greatest burden of MRSA with children under 5 years of age and males being most affected. Medical wards have the highest S. aureus bacteremia rates, while intensive care units have the highest MRSA bacteremia rates. Patient age, admitting ward, and geographical district are the most important associated factors of resistance. MRSA acquisition rates have shown tremendous growth since 2009 but have since spiked and subsequently decreased. This may be due to the initiation of the National Guidelines on Antimicrobial Stewardship and Infectious Disease Surveillance. Further studies to determine the trajectory of infections are required to support these claims. IMPORTANCE S. aureus is the leading cause of a variety of devastating clinical conditions, including infective endocarditis, bacteremia, and pleuropulmonary infections. It is an important pathogen responsible for substantial morbidity and mortality. MRSA is a variant of interest originally responsible for difficult to treat hospital-acquired infections that has since achieved community spread throughout the world. Most investigations into the distribution of MRSA have focused exclusively on bloodborne infections within individual health care institutions for shorter periods. This has limited the analysis of a community-spread pathogen to snapshots within the hospital domain. This study sought to determine the demographic and geographical patterns of MRSA infections as well as how these have fluctuated over time within all public hospitals. This will also help in understanding the epidemiology and resistance trends of S. aureus, which will help clinicians to understand the clinical prospective and policy makers to design guidelines and strategies for treating such infections.


Subject(s)
Bacteremia , Community-Acquired Infections , Cross Infection , Methicillin-Resistant Staphylococcus aureus , Staphylococcal Infections , Male , Child , Humans , Child, Preschool , Staphylococcus aureus , Retrospective Studies , Prospective Studies , Staphylococcal Infections/drug therapy , Staphylococcal Infections/epidemiology , Community-Acquired Infections/epidemiology , South Africa/epidemiology , Cross Infection/epidemiology , Hospitals, Public , Bacteremia/drug therapy , Bacteremia/epidemiology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use
11.
Int. microbiol ; 26(2): 165-177, May. 2023. graf
Article in English | IBECS | ID: ibc-220213

ABSTRACT

Emergence of Candida auris, a multidrug-resistant yeast, demonstrates the urgent need for novel antifungal agents. Human antimicrobial peptides (AMPs) are naturally occurring molecules with wide spectrum antimicrobial activity, particularly against a variety of fungi. Therefore, this study examined the antifungal activity of seven different human AMPs against C. auris following the CLSI guidelines. The antifungal activity was further assessed using time kill curve and cell viability assays. For combination interaction, effectiveness of these peptides with three antifungals, fluconazole, amphotericin B, and caspofungin was done following standard protocols. To elucidate the antifungal mechanism, the effects of peptides on membrane permeability were investigated using propidium iodide staining method and confocal imaging. Antifungal susceptibility results showed that all the examined peptides possessed fungicidal effect against C. auris at different levels, with human β-defensin-3 being the most potent antifungal with MIC values ranging from 3.125 to 12.5 µg/ml. Time kill curves further confirmed the killing effect of all the tested peptides. Viability assay showed a significant decrease in the percentage of viable cells exposed to different inhibitory and fungicidal concentrations of each peptide (p < 0.01). Furthermore, peptides showed mostly synergistic interaction when combined with conventional antifungal drugs, with caspofungin showing 100% synergy when combined with different AMPs. As antifungal mechanism, peptides disrupted the membrane permeability at concentrations that correlated with the inhibition of growth. Overall, the findings of this study point towards the application of the tested peptides as a monotherapy or as a combination therapy with antifungal drugs to treat multidrug-resistant C. auris infections.(AU)


Subject(s)
Humans , Antimicrobial Cationic Peptides , Candida , Cell Membrane Permeability , Antifungal Agents , Research
12.
Bioorg Chem ; 136: 106562, 2023 07.
Article in English | MEDLINE | ID: mdl-37119782

ABSTRACT

The emergence of multidrug-resistant fungal pathogens such as Candida auris is one of the major reasons WHO has declared fungal infections as a public health threat. Multidrug resistance, high mortality rates, frequent misidentification, and involvement in hospital outbreaks of this fungus demand the development of novel therapeutic drugs. In this direction, we report the synthesis of novel pyrrolidine-based 1,2,3-triazole derivatives using Click Chemistry (CC) and evaluation of their antifungal susceptibility against C. auris following Clinical and Laboratory Standards Institute (CLSI) guidelines. The fungicidal activity of the most potent derivative (P6) was further quantitatively confirmed by the MUSE cell viability assay. For insight mechanisms, the effect of the most active derivative on cell cycle arrest was studied using MuseTM Cell Analyzer and apoptotic mode of cell death was determined by studying phosphatidylserine externalization and mitochondrial depolarization. In vitro susceptibility testing and viability assays showed that all the newly synthesized compounds have antifungal activity with P6 being the most potent derivative. Cell cycle analysis revealed that P6 arrested the cells in S-phase in a concentration dependent manner and the apoptotic mode of cell death was confirmed by the movement of cytochrome c from mitochondria to cytosol with membrane depolarization. The hemolytic assay confirmed the safe use of P6 for further in vivo studies.


Subject(s)
Antifungal Agents , Candida auris , Antifungal Agents/pharmacology , Candida , Alprostadil/pharmacology , Microbial Sensitivity Tests , Triazoles/pharmacology , Apoptosis , Cell Cycle Checkpoints
13.
Vaccines (Basel) ; 11(3)2023 Mar 16.
Article in English | MEDLINE | ID: mdl-36992262

ABSTRACT

Candida parapsilosis poses huge treatment challenges in the clinical settings of South Africa, and often causes infections among immunocompromised patients and underweight neonates. Cell wall proteins have been known to play vital roles in fungal pathogenesis, as these are the first points of contact toward environments, the host, and the immune system. This study characterized the cell wall immunodominant proteins of pathogenic yeast C. parapsilosis and evaluated their protective effects in mice, which could add value in vaccine development against the rising C. parapsilosis infections. Among different clinical strains, the most pathogenic and multidrug-resistant C. parapsilosis isolate was selected based on their susceptibility towards antifungal drugs, proteinase, and phospholipase secretions. Cell wall antigens were prepared by ß-mercaptoethanol/ammonium bicarbonate extraction from selected C. parapsilosis strains. Antigenic proteins were identified using LC-MS/MS, where 933 proteins were found, with 34 being immunodominant. The protective effect of the cell wall immunodominant proteins was observed by immunizing BALB/c mice with cell wall protein extracts. After the immunization and booster, the BALC/c mice were challenged with a lethal dose of C. parapsilosis. In vivo results demonstrated increased survival rates and lower fungal burden in vital organs in the immunized mice compared to the unimmunized mice, thereby confirming the immunogenic property of cell wall-associated proteins of C. parapsilosis. Therefore, these results advocated the potential of these cell wall proteins to act as biomarkers for the development of diagnostic assays and/or vaccines against infections caused by C. parapsilosis.

14.
Vaccines (Basel) ; 11(2)2023 Feb 18.
Article in English | MEDLINE | ID: mdl-36851356

ABSTRACT

Virus-like particles (VLPs) are empty, nanoscale structures morphologically resembling viruses. Internal cavity, noninfectious, and particulate nature with a high density of repeating epitopes, make them an ideal platform for vaccine development and drug delivery. Commercial use of Gardasil-9 and Cervarix showed the usefulness of VLPs in vaccine formulation. Further, chimeric VLPs allow the raising of an immune response against different immunogens and thereby can help reduce the generation of medical or clinical waste. The economically viable production of VLPs significantly impacts their usage, application, and availability. To this end, several hosts have been used and tested. The present review will discuss VLPs produced using different yeasts as fermentation hosts. We also compile a list of studies highlighting the expression and purification of VLPs using a yeast-based platform. We also discuss the advantages of using yeast to generate VLPs over other available systems. Further, the issues or limitations of yeasts for producing VLPs are also summarized. The review also compiles a list of yeast-derived VLP-based vaccines that are presently in public use or in different phases of clinical trials.

15.
J Infect Public Health ; 16(2): 233-249, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36603376

ABSTRACT

Over the last few years, the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) unleashed a global public health catastrophe that had a substantial influence on human physical and mental health, the global economy, and socio-political dynamics. SARS-CoV-2 is a respiratory pathogen and the cause of ongoing COVID-19 pandemic, which testified how unprepared humans are for pandemics. Scientists and policymakers continue to face challenges in developing ideal therapeutic agents and vaccines, while at the same time deciphering the pathology and immunology of SARS-CoV-2. Challenges in the early part of the pandemic included the rapid development of diagnostic assays, vaccines, and therapeutic agents. The ongoing transmission of COVID-19 is coupled with the emergence of viral variants that differ in their transmission efficiency, virulence, and vaccine susceptibility, thus complicating the spread of the pandemic. Our understanding of how the human immune system responds to these viruses as well as the patient groups (such as the elderly and immunocompromised individuals) who are often more susceptible to serious illness have both been aided by this epidemic. COVID-19 causes different symptoms to occur at different stages of infection, making it difficult to determine distinct treatment regimens employed for the various clinical phases of the disease. Unsurprisingly, determining the efficacy of currently available medications and developing novel therapeutic strategies have been a process of trial and error. The global scientific community collaborated to research and develop vaccines at a neck-breaking speed. This review summarises the overall picture of the COVID-19 pandemic, different mutations in SARS-CoV-2, immune response, and the treatment modalities against SARS-CoV-2.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , COVID-19/epidemiology , COVID-19/immunology , COVID-19/therapy , Mutation , Pandemics/prevention & control , SARS-CoV-2/genetics
16.
Int Microbiol ; 26(2): 165-177, 2023 May.
Article in English | MEDLINE | ID: mdl-36329309

ABSTRACT

Emergence of Candida auris, a multidrug-resistant yeast, demonstrates the urgent need for novel antifungal agents. Human antimicrobial peptides (AMPs) are naturally occurring molecules with wide spectrum antimicrobial activity, particularly against a variety of fungi. Therefore, this study examined the antifungal activity of seven different human AMPs against C. auris following the CLSI guidelines. The antifungal activity was further assessed using time kill curve and cell viability assays. For combination interaction, effectiveness of these peptides with three antifungals, fluconazole, amphotericin B, and caspofungin was done following standard protocols. To elucidate the antifungal mechanism, the effects of peptides on membrane permeability were investigated using propidium iodide staining method and confocal imaging. Antifungal susceptibility results showed that all the examined peptides possessed fungicidal effect against C. auris at different levels, with human ß-defensin-3 being the most potent antifungal with MIC values ranging from 3.125 to 12.5 µg/ml. Time kill curves further confirmed the killing effect of all the tested peptides. Viability assay showed a significant decrease in the percentage of viable cells exposed to different inhibitory and fungicidal concentrations of each peptide (p < 0.01). Furthermore, peptides showed mostly synergistic interaction when combined with conventional antifungal drugs, with caspofungin showing 100% synergy when combined with different AMPs. As antifungal mechanism, peptides disrupted the membrane permeability at concentrations that correlated with the inhibition of growth. Overall, the findings of this study point towards the application of the tested peptides as a monotherapy or as a combination therapy with antifungal drugs to treat multidrug-resistant C. auris infections.


Subject(s)
Antifungal Agents , Candida auris , Humans , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Caspofungin/pharmacology , Antimicrobial Peptides , Candida , Peptides/pharmacology , Microbial Sensitivity Tests
17.
Indian J Tuberc ; 69(4): 465-469, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36460377

ABSTRACT

BACKGROUND: Female genital tuberculosis (FGTB) causes infertility in a significant number of females. The immunological impact of tuberculosis on endometrium in infertile females has not been studied before. The present study was designed to evaluate markers related to infiltrating immune cells and implantation in endometrial aspiration from infertile females and correlate with conventional tests and polymerase chain reaction (PCR) for tuberculosis (TB). METHODS: It was a prospective cohort study with 385 patients out of which IHC was done in 306 over a period of 3 years from 2013 to 2016 in a tertiary care hospital. Women with infertility, 20-35 years of age, without history of pulmonary TB or intake of antitubercular therapy were included. Endometrial samples were subjected to PCR for TB along with microbiological and histological examination for TB. Immunohistochemistry for CD45, CD3, CD20, CD4, CD8, CD68, CD138, Interferon gamma, Interleukin 10 (IL-10) and implantation markers MUC1 and Notch 1 were done on the endometrial samples along with 25 control subjects. RESULTS: Conventional tests for tuberculosis like staining for acid fast bacilli (AFB), granuloma on histology or culture positivity were seen in 2.61% (6/306; 1.96% had granulomas, 1/306; 0.32% was AFB positive, 2/306; 0.6% were liquid culture positive). PCR was positive in 190/306 (62.09%). CD3, CD20, CD45, CD68, CD4, CD8 and CD 138 expressing infiltrating cells were not significantly related to PCR positive cases. Interferon gamma expressing lymphocytes were significantly higher (38.94%) in PCR positive endometria compared to 26.72% in the PCR negative (p = 0.04). Notch -1 expression correlated significantly with the occurrence of pregnancy. A trend towards high intensity expression of Notch1 was seen in PCR negative cases. MUC-1 expression did not correlate with pregnancy although interferon gamma expression was significantly related to low intensity MUC1 expression. CONCLUSIONS: Immunohistochemical markers are not reliable tests in diagnosis of FGTB. Notch 1 expression though showing correlation with pregnancy has to be further evaluated with a panel of other implantation markers. STUDY FUNDING: Indian Council of Medical Research, New Delhi, India.


Subject(s)
Infertility , Tuberculosis, Female Genital , Pregnancy , Female , Humans , Tuberculosis, Female Genital/complications , Tuberculosis, Female Genital/diagnosis , Interferon-gamma , Prospective Studies , Biopsy , Endometrium , Biomarkers
18.
J Fungi (Basel) ; 8(12)2022 Dec 14.
Article in English | MEDLINE | ID: mdl-36547631

ABSTRACT

Candida auris has emerged as a pan-resistant pathogenic yeast among immunocompromised patients worldwide. As this pathogen is involved in biofilm-associated infections with serious medical manifestations due to the collective expression of pathogenic attributes and factors associated with drug resistance, successful treatment becomes a major concern. In the present study, we investigated the candidicidal activity of a plant defensin peptide named defensin-like protein 1 (D-lp1) against twenty-five clinical strains of C. auris. Furthermore, following the standard protocols, the D-lp1 was analyzed for its anti-biofilm and anti-virulence properties. The impact of these peptides on membrane integrity was also evaluated. For cytotoxicity determination, a hemolytic assay was conducted using horse blood. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values ranged from 0.047-0.78 mg/mL and 0.095-1.56 mg/mL, respectively. D-lp1 at sub-inhibitory concentrations potentially abrogated both biofilm formation and 24-h mature biofilms. Similarly, the peptide severely impacted virulence attributes in the clinical strain of C. auris. For the insight mechanism, D-lp1 displayed a strong impact on the cell membrane integrity of the test pathogen. It is important to note that D-lp1 at sub-inhibitory concentrations displayed minimal hemolytic activity against horse blood cells. Therefore, it is highly useful to correlate the anti-Candida property of D-lp1 along with anti-biofilm and anti-virulent properties against C. auris, with the aim of discovering an alternative strategy for combating serious biofilm-associated infections caused by C. auris.

19.
Int. microbiol ; 25(4): 769-779, Nov. 2022. graf
Article in English | IBECS | ID: ibc-216244

ABSTRACT

Infections caused by Candida albicans are rising due to increment in drug resistance and a limited arsenal of conventional antifungal drugs. Thus, elucidating the novel antifungal targets still represent an alternative that could overcome the problem of multidrug resistance (MDR). In this study, we have uncovered the distinctive effect of aminophospholipid translocase (Drs2p) deletion on major MDR mechanisms of C. albicans. We determined that efflux activity was diminished in Δdrs2 mutant as revealed by extracellular rhodamine 6G (R6G) efflux and flow cytometry. Moreover, we further unveiled that Δdrs2 mutant displayed decreased ergosterol content and increased membrane fluidity. Furthermore, Drs2p deletion affects the virulence attributes and led to inhibited hyphal growth and reduced biofilm formation. Additionally, THP-1 cell lines’ mediated host–pathogen interaction studies revealed that Δdrs2 mutant displayed enhanced phagocytosis and altered cytokine production leading to increased IL-6 and decreased IL-10 production. Taken together, the present study demonstrates the relevance of Drs2p in C. albicans and consequently disrupting pathways known for mediating drug resistance and immune recognition. Comprehensive studies are further required to authenticate Drs2p as a novel antifungal drug target.(AU)


Subject(s)
Humans , Candida albicans , Drug Resistance , Antifungal Agents , Host-Pathogen Interactions , Immunity , Microbiology , Communicable Diseases
20.
Pharmaceutics ; 14(10)2022 Sep 21.
Article in English | MEDLINE | ID: mdl-36297425

ABSTRACT

Infections by non-albicans Candida species have increased drastically in the past few decades. Candida glabrata is one of the most common opportunistic fungal pathogens in immunocompromised individuals, owing to its capability to attach to various human cell types and medical devices and being intrinsically weakly susceptible to azoles. Immunotherapy, including the development of antifungal vaccines, has been recognized as an alternative approach for preventing and treating fungal infections. Secretory proteins play a crucial role in establishing host-pathogen interactions and are also responsible for eliciting an immune response in the host during candidiasis. Therefore, fungal secretomes can provide promising protein candidates for antifungal vaccine development. This study attempts to uncover the presence of immunodominant antigenic proteins in the C. glabrata secretome and delineate their role in various biological processes and their potency in the development of antifungal vaccines. LC-MS/MS results uncovered that C. glabrata secretome consisted of 583 proteins, among which 33 were identified as antigenic proteins. The protection ability of secretory proteins against hematogenously disseminated infection caused by C. glabrata was evaluated in BALB/c mice. After immunization and booster doses, all the animals were challenged with a lethal dose of C. glabrata. All the mice showing signs of distress were sacrificed post-infection, and target organs were collected, followed by histopathology and C. glabrata (CFU/mg) estimation. Our results showed a lower fungal burden in target organs and increased survival in immunized mice compared to the infection control group, thus revealing the immunogenic property of secreted proteins. Thus, identified secretome proteins of C. glabrata have the potential to act as antigenic proteins, which can serve as potential candidates for the development of antifungal vaccines. This study also emphasizes the importance of a mass-spectrometry approach to identifying the antigenic proteins in C. glabrata secretome.

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