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Candida albicans is the predominant cause of systemic candidiasis, although other non albicans Candida species are progressively becoming more widespread nowadays. Candida auris has emerged as a deadly multidrug-resistant fungal pathogen, posing a significant threat to global public health. In the absence of effective antifungal therapies, the development of a vaccine against C. auris infections is imperative. Enolase, a key glycolytic enzyme, has emerged as a promising vaccine candidate due to its immunogenic properties and essential role in fungal virulence. Herein, full-length Enolase gene sequences from C. albicans and C. auris were cloned into suitable expression vector and transformed into Escherichia coli expression hosts. Recombinant Enolase proteins were successfully expressed and purified using affinity chromatography under native conditions, followed by SDS-PAGE characterization and Western blot analysis. CD spectroscopy verified the existence of expressed proteins in soluble native conformation. Preliminary in silico studies verified the immunogenicity of recombinant Enolase proteins isolated from both C. albicans and C. auris. Furthermore, bioinformatics analysis revealed conserved B-cell and T-cell epitopes across C. albicans and C. auris Enolase proteins, suggesting potential cross-reactivity and broad-spectrumvaccine efficacy. Our findings are anticipated to play a role in advancing therapeutic as well as diagnostic strategies against systemic candidiasis. [ABSTRACT FROM AUTHOR]

Candida albicans is an opportunistic fungal pathogen that can cause systemic infections in immunocompromised individuals. Morphological transition and biofilm formation are major virulence factors of C. albicans. Moreover, biofilm enhances resistance to antifungal agents. Therefore, it is urgent to identify new and effective compounds to target the biofilm of C. albicans. In the present study, the antifungal activities of equol against C. albicans were investigated. In vitro, the microdilution analysis and spot assay result showed that equol exhibited potent inhibitory activities against C. albicans. Further investigations confirmed that the antifungal effects of equol involved interference with the transition from yeast to hypha and biofilm formation of C. albicans. In addition, transcriptome sequencing and reverse transcription-quantitative PCR (qRT-PCR) analysis showed that equol significantly downregulated the expression of several genes in the Ras1-cAMP-PKA pathway related to hyphae and biofilm formation, and significantly upregulated the expression of the negative transcriptional repressors RFG1 and TUP1. Moreover, equol effectively reduced the production of cAMP, a key messenger in the Ras1-cAMP-PKA pathway, while supplementation with cAMP partly rescued the equol-induced defects in hyphal development. Furthermore, in a mouse model of systemic candidiasis (SC), equol treatment significantly decreased the fungal burden (liver, kidneys, and lung) in mice and local tissue damage, while enhancing the production of interleukin-10 (IL-10). Together, these findings confirm that equol is a potentially effective agent for treatment of SC.

ABSTRACT T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) is an inhibitory receptor expressed by T and natural killer cells. Here, we used TIGIT knockout (KO) mice to demonstrate that mouse TIGIT directly interacts with Candida albicans. Reduced fungal growth and colonization were observed when TIGIT-KO splenocytes were co-cultured with C. albicans compared to the wild type (WT). In a systemic candidiasis model, TIGIT-KO mice exhibited improved survival and reduced body weight loss compared to WT mice. Organ-specific fungal burden assessment revealed significantly lower fungal loads in the kidneys, spleen, and lungs of TIGIT-KO mice. Finally, we show that the agglutinin-like sequence proteins ALS6, ALS7, and ALS9 of C. albicans are ligands for TIGIT and that the absence of these proteins abolishes the TIGIT effect in vivo. Our results identify the significance of TIGIT in modulating host defense against C. albicans and highlight the potential therapeutic implications for C. albicans infections.IMPORTANCEOur results identify the significance of T cell immunoreceptor with immunoglobulin and ITIM domain in modulating host defense against Candida albicans and highlight the potential therapeutic implications for C. albicans infections.

Candida albicans is the predominant cause of systemic candidiasis, although other non albicans Candida species are progressively becoming more widespread nowadays. Candida auris has emerged as a deadly multidrug-resistant fungal pathogen, posing a significant threat to global public health. In the absence of effective antifungal therapies, the development of a vaccine against C. auris infections is imperative. Enolase, a key glycolytic enzyme, has emerged as a promising vaccine candidate due to its immunogenic properties and essential role in fungal virulence. Herein, full-length Enolase gene sequences from C. albicans and C. auris were cloned into suitable expression vector and transformed into Escherichia coli expression hosts. Recombinant Enolase proteins were successfully expressed and purified using affinity chromatography under native conditions, followed by SDS-PAGE characterization and Western blot analysis. CD spectroscopy verified the existence of expressed proteins in soluble native conformation. Preliminary in silico studies verified the immunogenicity of recombinant Enolase proteins isolated from both C. albicans and C. auris. Furthermore, bioinformatics analysis revealed conserved B-cell and T-cell epitopes across C. albicans and C. auris Enolase proteins, suggesting potential cross-reactivity and broad-spectrum vaccine efficacy. Our findings are anticipated to play a role in advancing therapeutic as well as diagnostic strategies against systemic candidiasis.

The sensitivity of the (1-3)-β-D-glucan (BDG) diagnostic test for candidemia varies in different clinical settings, and its usefulness in early diagnosis of candidemia is suboptimal. We evaluated the sensitivity of the test for early candidemia prediction. All adult patients with culture-proven candidemia who underwent a serum Goldstream Fungus (1-3)-β-D-Glucan Test within seven days prior to candidemia onset at a tertiary referral hospital between January 2017 and May 2021 were included. Any-positive BDG results within seven days prior to candidemia onset were obtained in 38 out of 93 (40.9%) patients. The positive rate increased when the test was performed near the day of candidemia onset (P=0.04) but reached only 52% on the day of candidemia onset. We observed no significant differences between BDG-positive and -negative groups in terms of underlying disease, risk factors for candidemia, clinical presentation, origin of candidemia, and 30-day mortality. Candida albicans was significantly associated with positive BDG results than with all-negative BDG results (P=0.04). The Goldstream BDG test is unreliable for candidemia prediction because of its low sensitivity. Negative BDG results in patients with a high risk of invasive candidiasis should be interpreted with caution. [ABSTRACT FROM AUTHOR]

Oral mucositis is highly prevalent among the elderly, for whom oral care is often difficult. Oral mucositis, such as candidiasis, can induce systemic fungemia. Antifungal prophylaxis may be useful in such cases to prevent systemic fungemia; however, studies on this are limited. The objective of this study was to demonstrate the effectiveness of antifungal prophylaxis to prevent systemic Candida dissemination compared to oral care using a mice model. Oral candidiasis was induced using chemotherapy and inoculation with C. albicans in 8-week-old male mice. Group A was given oral care, Group B was orally administered an antifungal drug, Group C was intravenously administered an antifungal drug, and Group D was used as the negative control group. Macroscopic features of the tongue surface, colony forming units (CFU) on the tongue, and blood culture for C. albicans were evaluated. CFU was significantly higher in Group A than in Groups B and C. The oral care group, but not the groups administered antifungal agents, showed significantly higher positive numbers of animals with C. albicans in the blood as compared to the control group, indicating the effectiveness of antifungal prophylaxis over oral care. Antifungal prophylaxis may be an option for the prevention of systemic fungemia in individuals with difficulty in oral care.

Background: Candidiasis is the most common cause of fungal sepsis, and new agents are of interest to ameliorate current deficiencies in therapy. Nikkomycin Z (NIKZ) is an inhibitor of chitin synthase, interfering with fungal cell wall development. Objectives/Methods: We studied NIKZ therapy of disseminated murine candidiasis, via continuous drug exposure, in drinking water, to compensate for rapid clearance of the drug. Results: Drinking, and thus drug intake in the NIKZ groups, as well as body weight, was affected by the degree of illness. NIKZ effect on survival, despite reduced drinking initially after infection, was highly efficacious and dose‐related, and comparable to fluconazole, though neither were curative with the regimens employed. The challenge was rapidly lethal to all untreated animals, whereas NIKZ groups achieved >50% survival. Assays of residual fungal infection were consistent with impressions of efficacy based on survival. Although NIKZ MIC for Candida albicans appeared unpromising, mycelial formation assays more closely correlated with in vivo observations. Conclusions: In vitro‐in vivo disparity may be explained by NIKZ tissue concentration in the target tissue and/or by enhanced NIKZ action on mycelial formation, a morphological change in vivo wherein chitin synthesis is more critical, compared to NIKZ activity in inhibiting planktonic growth. A sustained release oral form of NIKZ in drug development for humans could hold promise, possibly also in future exploring previously demonstrated synergy in vitro with other antifungals. [ABSTRACT FROM AUTHOR]

DNA polymerase ε (Polε) is an essential replicative polymerase consisting of Pol2, Dpb2, Dpb3, and Dpb4 subunits and has not been explored in the pathogenic yeast Candida albicans. C. albicans is accountable for >40% of deaths due to systemic candidiasis per year worldwide. Genome plasticity is one of the adaptive mechanisms associated with virulence, and as it is associated with DNA polymerase function, this study explored the role of Polε in genome stability and pathogenesis of C. albicans. POL2 and DPB2 are haploinsufficient, but DPB3 and DPB4 are dispensable for cell survival in diploid C. albicans . However, unlike in Saccharomyces cerevisiae , loss of any or both of the nonessential subunits or defective interaction between the two resulted in slow growth and temperature-sensitive phenotypes. Knockout strains of C. albicans (dpb3 ΔΔ and dpb4 ΔΔ and dpb3 ΔΔ dpb4 ΔΔ) also exhibited sensitivity to genotoxic agents and delayed cell cycle progression. Reduced processive DNA synthesis and increased rate of mutagenesis were observed in dpb3 and dpb4 null strains. Whole-genome sequencing further confirmed the accumulation of indels and SNPs majorly in the intergenic repeat regions of the chromosomes of dpb3 ΔΔ dpb4 ΔΔ. Polε-defective strains were constitutively filamentous and non-pathogenic in mice models of systemic candidiasis. Altogether, this study showed that the function of the Dpb3-Dpb4 subcomplex is critical for fungal morphogenesis and virulence besides its role as a structural component of Polε in DNA replication and genome stability; thus, their interacting interface may be targeted to develop antifungal drugs., Importance: This study explored the role of DNA polymerase epsilon, especially its non-essential structural subunits in Candida albicans biology. Apart from their role in DNA replication and genome stability, the Dpb3-Dpb4 subcomplex regulates morphological switching and virulence. Since the defective strain is locked in filamentous form and is avirulent, the complex may be targeted for anti-fungal drug development.

Background: Candida albicans is an opportunistic pathogen commonly found in human mucous membranes. In light of the escalating challenge posed by antibiotic resistance of C. albicans strains worldwide, it is an urgently necessary to explore alternative therapeutic options., Objective: This study aims to assess the efficacy of two Cinnamaldehyde derivatives, 2-Cl Cinnamaldehyde (2-Cl CA) and 4-Cl Cinnamaldehyde (4-Cl CA), against C. albicans through both in vitro experiments and in vivo murine models and to evaluate their potential as new drug candidates for treating C. albicans., Methods and Results: The minimum inhibitory concentrations (MICs) of Cinnamaldehyde 2-Cl and 4-Cl benzene ring derivatives against C. albicans were 25 μg/mL. Time-killing experiments revealed that both Cinnamaldehyde derivatives exhibited fungicidal activity against C. albicans at concentrations of 5 MIC and 10 MIC. In the checkerboard experiment, 4-Cl CA did not show any antagonistic effect when combined with first-line antifungal drugs. Instead, it exhibited additive effects in combination with nystatin. Both 2-Cl and 4-Cl CA demonstrated inhibitory activity against C. albicans biofilm formation, especially at 8 MIC and 16 MIC concentrations. In C. albicans biofilm eradication experiments, although high drug concentrations of 2-Cl and 4-Cl CA were unable to eradicate the biofilm completely, they were still effective in killing C. albicans cells within the biofilm. Moreover, sub-inhibitory concentrations of 4-Cl CA (ranging from 5 to 20 μg/mL) significantly inhibited cell aggregation and hyphal formation. Furthermore, 4-Cl CA effectively inhibited intracellular C. albicans infection in macrophages. Lastly, the effectiveness of 4-Cl CA was evaluated in a mouse model of hematogenous disseminated candidiasis caused by C. albicans, which revealed that 4-Cl CA significantly reduced fungal burden and improved mouse survival compared to the untreated controls., Conclusion: The 4-Cl CA exhibited inhibitory effects against C. albicans through both in vivo and in vitro models, demonstrating its therapeutic potential as a promising new drug candidate for treating drug-resistant candidiasis albicans., Competing Interests: Declaration of competing interest There are no conflicts to declare., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) is an inhibitory receptor expressed by T and natural killer cells. Here, we used TIGIT knockout (KO) mice to demonstrate that mouse TIGIT directly interacts with Candida albicans . Reduced fungal growth and colonization were observed when TIGIT-KO splenocytes were co-cultured with C. albicans compared to the wild type (WT). In a systemic candidiasis model, TIGIT-KO mice exhibited improved survival and reduced body weight loss compared to WT mice. Organ-specific fungal burden assessment revealed significantly lower fungal loads in the kidneys, spleen, and lungs of TIGIT-KO mice. Finally, we show that the agglutinin-like sequence proteins ALS6, ALS7, and ALS9 of C. albicans are ligands for TIGIT and that the absence of these proteins abolishes the TIGIT effect in vivo . Our results identify the significance of TIGIT in modulating host defense against C. albicans and highlight the potential therapeutic implications for C. albicans infections., Importance: Our results identify the significance of T cell immunoreceptor with immunoglobulin and ITIM domain in modulating host defense against Candida albicans and highlight the potential therapeutic implications for C. albicans infections.

There is an increase in the prevalence of Candida fluco-R, there is a transition from strains of C. albicans to C. non-albicans. Diagnosis of invasive fungal infections is based on a clinical picture and risk factor assessment with subsequent retrospective confirmation of the diagnosis by a microbiological method. Echinocandines are the drugs of choice in the therapy of invasive/systemic mycoses in cancer patients.

Systemic candidiasis, which is mainly caused by Candida albicans, is a serious acute fungal infection in the clinical setting. In a previous study, we reported that compound 22h (designated as AB-22 in this study), a vinyl sulfate compound, is a fast-acting fungicidal agent against a broad spectrum of fungal pathogens. In this study, we aimed to further analyze the in vitro and in vivo efficacy of AB-22 against filamentation, biofilm formation, and virulence of C. albicans. Under in vitro hyphal growth-inducing condition, AB-22 effectively inhibited germ tube formation and hyphal growth, which are required for the initiation of biofilm formation. Indeed, AB-22 significantly suppressed C. albicans biofilm formation in a dose-dependent manner. Moreover, AB-22 treatment inhibited the normal induction of ALS3, HWP1, and ECE1, which are all required for hyphal transition in C. albicans. Furthermore, AB-22 treatment increased the survival of mice systemically infected with C. albicans. In conclusion, in addition to its fungicidal activity, AB-22 inhibits filamentation and biofilm formation in C. albicans, which could collectively contribute to its potent in vivo efficacy against systemic candidiasis. [ABSTRACT FROM AUTHOR]

Shaheer Hasan Khan,1,* Hina Younus,1,* Khaled S Allemailem,2 Ahmad Almatroudi,2 Faris Alrumaihi,2 Abdulmohsen M Alruwetei,2 Mohammed A Alsahli,2 Arif Khan,3 Masood Alam Khan3 1Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India; 2Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraidah 51452, Saudi Arabia; 3Department of Basic Health Sciences, College of Applied Medical Sciences, Qassim University, Buraidah, 51452, Saudi Arabia*These authors contributed equally to this workCorrespondence: Masood Alam KhanDepartment of Basic Health Sciences, College of Applied Medical Sciences, Qassim University, Buraydah, KSA 51452 Tel +966-507059437Fax +966-63801628Email a_khan@qu.edu.saBackground: Fungal infections are becoming more prevalent and threatening because of the continuous emergence of azole-resistant fungal infections. The present study was aimed to assess the activity of free Methylglyoxal (MG) or MG-conjugated chitosan nanoparticles (MGCN) against fluconazole-resistant Candida albicans.Materials and Methods: A novel formulation of MGCN was prepared and characterized to determine their size, shape and polydispersity index. Moreover, the efficacy of fluconazole or MG or MGCN was determined against intracellular C. albicans in macrophages and the systematic candidiasis in a murine model. The safety of MG or MGCN was tested in mice by analyzing the levels of hepatic and renal toxicity parameters.Results: Candida albicans did not respond to fluconazole, even at the highest dose of 20 mg/kg, whereas MG and MGCN effectively eliminated C. albicans from the macrophages and infected mice. Mice in the group treated with MGCN at a dose of 10 mg/kg exhibited a 90% survival rate and showed the lowest fungal load in the kidney, whereas the mice treated with free MG at the same dose exhibited 50% survival rate. Moreover, the administration of MG or MGCN did not induce any liver and kidney toxicity in the treated mice.Conclusion: The findings of the present work suggest that MGCN may be proved a promising therapeutic formulation to treat azole-resistant C. albicans infections.Keywords: chitosan nanoparticles, fluconazole-resistant, systemic Candidiasis, methylglyoxal

Nosocomial Candida colonization causes Systemic candidiasis in human with invasive infections in immunocompromised patients. Of all Candida spp., C. albicans is dominant in morbidity of all systemic candidiasis but C. tropicalis is phenomenal in mortality, virulence aspects and resistance development against antifungal drugs. The present study investigated the synergistic anti-virulent activity of myristic acid (MA) and palmitic acid (PA) against insidious dimorphic Candida spp. (C. albicans and C. tropicalis). In vitro and qPCR results revealed the mechanisms of MA-PA combination effectively inhibiting various virulence aspects such as biofilm, hyphal formation, secreted aspartyl proteases, lipases, ergosterol biosynthesis and drug effluxes. Further, in Danio rerio (Zebrafish), the MA-PA treatment increased the survival of animals and also the treated groups showed decreased level of fungal burden compared to the infected controls, after 3rd day of post infection. Histopathology of vital organs and SEM analysis of skin revealed a drastic recovery and reduced the inflammation of both Candida spp. infections in MA-PA treated animals. In addition, MA-PA treatment reduced the haemolysin and increased the susceptibility of Candida spp. in human blood model. Hence, this study suggested the therapeutic utilization of MA-PA as synergistic combination for their anti-inflammatory potency against systemic candidiasis and candidemia.

We reported previously a recombinant protein (rP-HSP90C) containing epitope C from heat shock protein 90 of Candida albicans mediates protective immune responses against systemic candidiasis. However, it exhibits weak immunogenicity. Therefore, we evaluated the potential and mechanisms of thermosensitive chitosan hydrogel (CH-HG) as an adjuvant in rP-HSP90C vaccine. CH-HG synthesized by ionic cross-linking showed buffering capacity and control-released rP-HSP90C in vitro. In comparison to naked rP-HSP90C, CH-HG-loaded rP-HSP90C (CH-HG/rP-HSP90C) not only evoked a long-lasting rP-HSP90C-specific IgG, but also enhanced Th1, Th2, Th17 responses and the ratio of Th1/Th2 in vivo; Meanwhile, CH-HG/rP-HSP90C provoked a stronger CTL response than rP-HSP90C. Notably, CH-HG increased the protective immune responses against systemic candidiasis in rP-HSP90C-immunized mice since CH-HG/rP-HSP90C enhanced the survival rate of infected mice, and diminished the CFUs in kidneys compared to rP-HSP90C, which were similar to that of QuilA. Further in vitro investigation displayed CH-HG upgraded the expressions of costimulators, MHCs and cytokines in BMDCs compared to rP-HSP90C；CH-HG also promoted cellular uptake, endosomal escape and "cross-presentation" of rP-HSP90C. In addition, it recruited immune cells at the injection site. Our study demonstrated that CH-HG can be an efficient adjuvant in fungal vaccines. • CH-HG had the abilities of control-release rP-HSP90C and buffering capacity. • CH-HG promoted humoral and cellular immune responses in rP-HSP90C-immunized mice. • CH-HG increased survival rate in rP-HSP90C-immunized mice infected with C. albicans. • CH-HG activated synergistically BMDCs and enhanced "cross-presentation" of rP-HSP90C. [ABSTRACT FROM AUTHOR]

In this study, we investigated the therapeutic efficacy of a combination of liposomal amphotericin B (Lip-Amp B) and Methylglyoxal (Lip-MG) against Candida albicans in the leukopoenic mice. The antifungal efficacy of Lip-Amp B or Lip-MG or a combination of Lip-Amp B and Lip-MG was evaluated by the analysis of the survival rate and the fungal load in the treated mice. The immune-stimulatory effect of Lip-MG on macrophages was evaluated by analysing the secretion of proinflammatory cytokines. C. albicans infected mice treated at the doses of 1 and 2 mg/kg of Lip-Amp B showed 20% and 50% survival rates, respectively. Whereas the mice treated with free Amp B at the same doses died within 40 days of treatment. Interestingly, C. albicans infected mice treated with a combination of Lip-Amp B and Lip-MG had 70% survival rate on day 40 postinfection. Moreover, treatment of macrophages with Lip-MG increased their fungicidal activity and the secretion of proinflammatory cytokines, including TNF-α and IL-1β. These findings suggested that co-treatment with Lip-Amp B and Lip-MG had a synergistic effect and could be effective against C. albicans in immunocompromised subjects. [ABSTRACT FROM AUTHOR]

Candida albicans is considered an exclusive etiologic agent of candidiasis, a very common fungal infection in human. The expression of virulence factors contributes highly to the pathogenicity of C. albicans. These factors include biofilm formation, yeast-to-hyphal transition, adhesins, aspartyl proteases, and phospholipases secretion. Moreover, resistance development is a critical issue for the therapeutic failure of antifungal agents against systemic candidiasis. To circumvent resistance development, the present study investigated the virulence targeted therapeutic activity of the phyto-bioactive compound morin against C. albicans. Morin is a natural compound commonly found in medicinal plants and widely used in the pharmaceutical and cosmetic products/industries. The present study explicated the significant inhibitory potential of morin against biofilm formation and other virulence factors' production, such as yeast-hyphal formation, phospholipase, and exopolymeric substances, in C. albicans. Further, qPCR analysis confirmed the downregulation of biofilm and virlence-related genes in C. albicans upon morin treatment, which is in correspondence with the in vitro bioassays. Further, the docking analysis revealed that morin shows strong affinity with Hwp-1 protein, which regulates the expression of biofilm and hyphal formation in C. albicans and, thereby, abolishes fungal pathogenicity. Moreover, the anti-infective potential of morin against C. albicans -associated systemic candidiasis is confirmed through an in vivo approach using biomedical model organism zebrafish (Danio rerio). The outcomes of the in vivo study demonstrate that the morin treatment effectively rescues animals from C. albicans infections and extends their survival rate by inhibiting the internal colonization of C. albicans. Histopathology analysis revealed extensive candidiasis-related pathognomonic changes in the gills, intestine, and kidney of animals infected with C. albicans , while no extensive abnormalities were observed in morin-treated animals. The results evidenced that morin has the ability to protect against the pathognomonic effect and histopathological lesions caused by C. albicans infection in zebrafish. Thus, the present study suggests that the utilization of morin could act as a potent therapeutic medication for C. albicans instigated candidiasis. [ABSTRACT FROM AUTHOR]

Objective: One of the major clinical problems is the resistance of Candida speciestowards most of antifungals. The search for new antifungal drug from plants have helped to overcome this problem. This study evaluated the effects of Allium hirtifolium and Allium sativumextracts on Candida tropicalis both in vitro and in a mouse model of systemic candidiasis. Materials and Methods: In this study, clinical isolates of C. tropicalis were isolated and identified from immunocompromised patients with recurrent candidiasis. Antifungal susceptibilities assessment and time kill study of aqueous and ethanolic extracts of A. hirtifolium and A. sativumextracts were done against C. tropicalis. The in vivo activity of aqueous extracts of A. hirtifolium and A. sativumwere evaluated in a mouse model of systemiccandidiasis caused by C. tropicalis through estimating the host survival time, fungal burden and histopathologic analyses. Results: The aqueous and ethanolic extracts of A. hirtifolium and A. sativum exhibited significant antifungal activity against C. tropicalis. In time kill study, A. hirtifolium and A. sativum extracts exhibited significant effects against C. tropicalis (p

Systemic candidiasis is the fourth most common bloodstream infection in ICU patients worldwide. Although C. albicans is a predominant species causing systemic candidiasis, infections caused by non-albicans Candida (NAC) species are increasingly becoming more prevalent globally along with the emergence of drug resistance. The diagnosis of systemic candidiasis is difficult due to the absence of significant clinical symptoms in patients. We investigated the diagnostic potential of recombinant secreted aspartyl proteinase 2 (rSap2) from C. parapsilosis for the detection of Candida infection. The rSap2 protein was successfully cloned, expressed and purified using Ni-NTA chromatography under denaturing conditions using an E. coli-based prokaryotic expression system, and refolded using a multi-step dialysis procedure. Structural analysis by CD and FTIR spectroscopy revealed the refolded protein to be in its near native conformation. Immunogenicity analysis demonstrated the rSap2 protein to be highly immunogenic as evident from significantly high titers of Sap2-specific antibodies in antigen immunized Balb/c mice, compared to sham-immunized controls. The diagnostic potential of rSap2 protein was evaluated using immunoblotting and ELISA assays using proven candidiasis patient serum and controls. Immunoblotting results indicate that reactivity to rSap2 was specific to candidiasis patient sera with no cross reactivity observed in healthy controls. Increased levels of anti-Sap2-specific Ig, IgG and IgM antibodies were observed in candidiasis patients compared to controls and was similar in sensitivity obtained when whole Candida was used as coating antigen. In summary, the rSap2 protein from C. parapsilosis has the potential to be used in the diagnosis of systemic candidiasis, providing a rapid, convenient, accurate and cost-effective strategy.

Systemic candidiasis is an invasive fungal infection caused by members of the genus Candida. The recent emergence of antifungal drug resistance and increased incidences of infections caused by non-albicans Candida species merit the need for developing immune therapies against Candida infections. Although the role of cellular immune responses in anti-Candida immunity is well established, less is known about the role of humoral immunity against systemic candidiasis. This review summarizes currently available information on humoral immune responses induced by several promising Candida vaccine candidates, which have been identified in the past few decades. The protective antibody and B-cell responses generated by polysaccharide antigens such as mannan, β-glucan, and laminarin, as well as protein antigens like agglutinin-like sequence gene (Als3), secreted aspartyl proteinase (Sap2), heat shock protein (Hsp90), hyphally-regulated protein (Hyr1), hyphal wall protein (Hwp1), enolase (Eno), phospholipase (PLB), pyruvate kinase (Pk), fructose bisphosphate aldolase (Fba1), superoxide dismutase gene (Sod5) and malate dehydrogenase (Mdh1), are outlined. As per studies reviewed, antibodies induced in response to leading Candida vaccine candidates contribute to protection against systemic candidiasis by utilizing a variety of mechanisms such as opsonization, complement fixation, neutralization, biofilm inhibition, direct candidacidal activity, etc. The contributions of B-cells in controlling fungal infections are also discussed. Promising results using anti-Candida monoclonal antibodies for passive antibody therapy reinforces the need for developing antibody-based therapeutics including anti-idiotypic antibodies, single-chain variable fragments, peptide mimotopes, and antibody-derived peptides. Future research involving combinatorial immunotherapies using humanized monoclonal antibodies along with antifungal drugs/cytokines may prove beneficial for treating invasive fungal infections.

Our previous proteomics data obtained from Candida albicans recovered after serial passage in a murine model of systemic infection revealed that Orf19.36.1 expression correlates with the virulence of the fungus. Therefore, the impact of ORF19.36.1 upon virulence was tested in this study. Materials & Methods : CRISPR-Cas9 technology was used to construct homozygous C. albicans orf19.36.1 null mutants and the phenotypes of these mutants examined in vitro (filamentation, invasion, adhesion, biofilm formation, hydrolase activities) and in vivo assays. Results: The deletion of ORF19.36.1 did not significantly impact the phenotypes examined or the virulence of C. albicans in two infection models. Conclusion: These results suggest that, although Orf19.36.1 expression correlates with virulence, this protein is not essential for C. albicans pathobiology. • Four barcoded orf19.36.1 mutants were constructed using CRISPR-Cas9 technology. • The disruption of ORF19.36.1 did not affect several virulence factors. • The inactivation of ORF19.36.1 did not attenuate the virulence in vivo. • ORF19.36.1 is not essential for the pathogenesis of C. albicans. • Orf19.36.1 is water soluble cytoplasmic protein containing S-phosphorylation site. [ABSTRACT FROM AUTHOR]

Antifungal resistance is the main health concern in the control of invasive fungal infections. This research was designed to further assess the antifungal activity of aryl-1,2,4-triazole-3-ylthio analogs of fluconazole (ATTAFs) against Candida albicans systemic candidiasis in the murine model. The murine model of systemic candidiasis was designed via the inoculation of 1 × 106 CFU of Candida albicans. The treatment dosages of 3.5 and 35 mg/kg per day were selected for ATTAFs and fluconazole, respectively. The median survival time (MST) was assayed for 30 days post-infection. The quantitative and qualitative (via histopathology staining) fungal burden was also assessed. Furthermore, immunohistochemistry and biochemistry assays were performed to monitor anti-inflammatory activity using the Cyclooxygenase-2 (Cox-2) marker and changes in serum protein levels. ATTAFs considerably improved the survival of the murine model (P < 0.003). Compared with fluconazole, the antifungal activity of ATTAFs and their MST showed no difference (P > 0.05). However, these compounds decreased the fungal burden in the kidneys, spleen, and liver. Our research indicates that ATTAF-1 and ATTAF-2 are effective therapeutic agents due to their fungal clearing and increasing the MST in the murine model of systemic candidiasis. Although we concluded that these components are novel and promising candidates for the management of invasive candidiasis, further studies are warranted to correlate these findings with clinical outcomes. [ABSTRACT FROM AUTHOR]

Objective(s): Systemic candidiasis is an infection of Candida albicans (C. albicans) causing disseminated disease and sepsis, invariably when host defenses are compromised. We investigated the histopathological changes as well as the lymphoproliferative responses and cytokine production of splenic cells after stimulation with Concanavalin A (Con A) and Pokeweed mitogen (PWM) in mice with disseminated candidiasis. Materials and Methods:Lymphoproliferative responses were stimulated in vitro with Con A (1 µg/ml) and PWM (1 µg/ml) mitogens in Roswell Park Memorial Institute (RPMI) 1640 media, and the production of interferon (IFN)-γ and interleukin-4 (IL-4) in the supernatants was measured by enzyme-linked immunosorbent assay (ELISA). Results: The results revealed that C. albicans organisms multiplied to a greater extent in the kidneys than in the liver and spleen of infected mice. The most predominant forms of C. albicans in different parts of the kidneys were yeast mixed with hyphal forms. Infected mice had a significantly increased proliferative response when splenocytes were stimulated with PWM (2.0±0.16) and Con A (1.9±0.19) (P

Candida albicans is the major pathogen isolated from nosocomial bloodstream infections, leading to higher mortality rates. Thus, due to its clinical relevance, studies aiming to understand host–pathogen interactions in C. albicans infection are necessary. Therefore, we performed proteomic analysis using a murine model of serial systemic infection by C. albicans to evaluate possible changes in the protein profile of the pathogen over time. Firstly, we observed a reduction in the median survival time of infected animals with increasing passage number, suggesting a higher pathogenicity acquired during repeated infections. By LC-MS/MS, it was possible to obtain protein profiles from the wild-type strain (WT) and compare them to proteins extracted from Candida cells recovered from infected tissues during passages one, three, and four (P1, P3, and P4). We obtained 56, 29, and 97 proteins in P1, P3, P4, respectively, all varying in abundance. Regarding biological processes, the majority of proteins were related to carbohydrate metabolism, stress responses and amino acid metabolism. The proteins were also categorized according to their potential role in virulence traits, such as biofilm production, yeast-to-hyphae transition, phenotypic switching, proteins related to stress responses, and uncharacterized proteins. Therefore, serial infection in combination with proteomic approach enabled us to deepen the existing knowledge about host-pathogen interactions.

Background: Antifungal resistance is the main health concern in the control of invasive fungal infections. This research was designed to further assess the antifungal activity of aryl-1,2,4-triazole-3-ylthio analogs of fluconazole (ATTAFs) against Candida albicans systemic candidiasis in the murine model., Materials & Methods: The murine model of systemic candidiasis was designed via the inoculation of 1 × 10 6 CFU of Candida albicans. The treatment dosages of 3.5 and 35 mg/kg per day were selected for ATTAFs and fluconazole, respectively. The median survival time (MST) was assayed for 30 days post-infection. The quantitative and qualitative (via histopathology staining) fungal burden was also assessed. Furthermore, immunohistochemistry and biochemistry assays were performed to monitor anti-inflammatory activity using the Cyclooxygenase-2 (Cox-2) marker and changes in serum protein levels., Results: ATTAFs considerably improved the survival of the murine model (P < 0.003). Compared with fluconazole, the antifungal activity of ATTAFs and their MST showed no difference (P > 0.05). However, these compounds decreased the fungal burden in the kidneys, spleen, and liver., Conclusion: Our research indicates that ATTAF-1 and ATTAF-2 are effective therapeutic agents due to their fungal clearing and increasing the MST in the murine model of systemic candidiasis. Although we concluded that these components are novel and promising candidates for the management of invasive candidiasis, further studies are warranted to correlate these findings with clinical outcomes., Competing Interests: Declaration of Competing Interest No potential conflicts of interest. The authors alone are responsible for the content and writing of the paper., (Copyright © 2023 SFMM. Published by Elsevier Masson SAS. All rights reserved.)

Candida albicans causes a high mortality rate in immunocompromised individuals, but the increased drug resistance challenges the current antifungal therapeutics. Fluphenazine (FPZ), a commonly used antipsychotic medication, can induce the expression of drug efflux pumps in C. albicans and, thus, may interfere with the therapeutic efficacy of antifungals, such as fluconazole (FLC) and amphotericin B (AmB). Here, we investigated the combined effects of FLC/FPZ and AmB/FPZ against C. albicans in vitro and in a systemic candidiasis mouse model. The antifungal activity of FLC was significantly reduced when supplemented with FPZ. The inhibitory effects of FLC on the expression of the Candida virulence-related genes ALS3 and HWP1 were antagonized by FPZ. However, FPZ enhanced the susceptibility of C. albicans to AmB and further downregulated the expression of ALS3 and HWP1 in a synergistic manner with AmB. FPZ also enhanced the gene expression of ERG11, a key gene of the ergosterol biosynthesis pathway that has been associated with the activities of both FLC and AmB. In our mammalian infection model, mice treated with FLC/FPZ showed notably poor living status and increased fungal burden in their kidneys and brains compared with those treated with FLC alone. Conversely, the combined application of AmB/FPZ significantly improved the survival rate, attenuated the weight loss and reduced the organ fungal burdens of the infected mice. These data suggest that FPZ antagonized the therapeutic efficacy of FLC but enhanced the antifungal activity of AmB in the treatment of candidiasis. [ABSTRACT FROM AUTHOR]

Candida albicans is the major pathogen isolated from nosocomial bloodstream infections, leading to higher mortality rates. Thus, due to its clinical relevance, studies aiming to understand host–pathogen interactions in C. albicans infection are necessary. Therefore, we performed proteomic analysis using a murine model of serial systemic infection by C. albicans to evaluate possible changes in the protein profile of the pathogen over time. Firstly, we observed a reduction in the median survival time of infected animals with increasing passage number, suggesting a higher pathogenicity acquired during repeated infections. By LC-MS/MS, it was possible to obtain protein profiles from the wild-type strain (WT) and compare them to proteins extracted from Candida cells recovered from infected tissues during passages one, three, and four (P1, P3, and P4). We obtained 56, 29, and 97 proteins in P1, P3, P4, respectively, all varying in abundance. Regarding biological processes, the majority of proteins were related to carbohydrate metabolism, stress responses and amino acid metabolism. The proteins were also categorized according to their potential role in virulence traits, such as biofilm production, yeast-to-hyphae transition, phenotypic switching, proteins related to stress responses, and uncharacterized proteins. Therefore, serial infection in combination with proteomic approach enabled us to deepen the existing knowledge about host-pathogen interactions. [ABSTRACT FROM AUTHOR]

Introduction & Objective: Vacuolar proteinase is an aspartic enzyme in Candida albicans (C. albicans) that is expressed by VAP gene and plays an important role in the development of systemic candidiasis. The aim of this study was to evaluate VAP gene expression in C. albicans strains isolated from patients with systemic candidiasis. Materials & Methods: The evaluation of VAP gene expression was performed using reverse transcriptase-polymerase chain reaction (RT-PCR) method and samples were electrophoresed in 1.5% agarose gels. In addition, a total of 48 female Balb/c mice (six-weeks old and weight of 25 g) were experimentally infected by various C. albicans strains and the level of VAP gene expression was assessed in yeasts obtained from the blood of infected mice. Results: The level of VAP gene expression in non-Iranian strains was significantly higher than those of Iranian strains (P

مقدمه: Toll like receptor-2 (TLR-2) نقش مهمی در فرایند شناسایی و راه‌اندازی پاسخ ایمنی علیه بسیاری از میکروارگانیسم‌ها از جمله Candida albicans دارد. داروی سیکلوفسفاماید، یکی از پرمصرف‌ترین داروهای شیمی درمانی است که موجب نوتروپنی شدید و سرکوب سیستم ایمنی می‌شود. در این مطالعه، پس از ایجاد بیماری Candidiasis منتشره و همچنین، تزریق سیکلوفسفاماید به منظور ایجاد نوتروپنی در موش‌های Balb/c، میانگین بیان ژن TLR2 اندازه‌گیری شد. روش‌ها: 28 سر موش ماده تهیه و به 4 گروه تقسیم شدند. سیکلوفسفاماید و Candida albicans به موش‌ها تزریق شد. پس از خونگیری از قلب و استخراج RNA و سنتز complementary DNA (cDNA)، بیان ژن TLR2 با روش Real-time polymerase chain reaction (Real-time PCR) سنجیده شد. داده‌ها با استفاده از روش CT∆∆2- و آزمون Kruskal–Wallis آنالیز شدند. یافته‌ها: با وجود افزایش میانگین بیان ژن مورد مطالعه در گروه دریافت کننده‌ی Candida albicans و گروه دریافت کننده‌ی سیکلوفسفاماید به همراه Candida albicans و از طرفی، کاهش میانگین بیان این ژن در گروه دریافت کننده‌ی سیکلوفسفاماید، همچنان از نظر آماری اختلاف معنی‌داری در بیان ژن TLR2 بین گروه شاهد و سایر گروه‌های مورد مطالعه مشاهده نشد (478/0 = P). نتیجه‌گیری: میانگین بیان ژن در گروه دریافت کننده‌ی Candida albicans و گروه دریافت کننده‌ی سیکلوفسفاماید و Candida albicans افزایش یافته و در گروه دریافت کننده‌ی سیکلوفسفاماید کاهش یافته بود، اما با این وجود، اختلاف معنی‌داری در بیان ژن TLR2 بین گروه شاهد و سایر گروه‌های مورد مطالعه مشاهده نشد (478/0 = P). با این حال، نتایج این مطالعه می‌تواند در انتخاب TLR2 و یا گیرنده‌ی آن به عنوان هدف درمانی با منوکلونال آنتی‌بادی و یا روش‌های ژن درمانی مورد بررسی قرار گیرد.

Background and Purpose: Use of curcumin, as a promising antifungal agent, is considered an alternative treatment for fungal infections; however, the low solubility of this agent limits its efficacy. Accordingly, in this study, we aimed to evaluate the in vitro and in vivo antifungal activities of dendrosomal nanocurcumin with improved solubility and bioavailability. Materials & Methods: The in vitro antifungal activities of several Candida species, including C. albicans, C. tropicalis, C. krusei, C. parapsilosis, and C. dubliniensis, were evaluated, using the broth microdilution method. In the in vivo study, different doses of nanocurcumin (5, 10, 20, and 40 mg/kg) were administered to mice with systemic C. albicans infection via intraperitoneal injection. All mice were euthanized at 20 days following the administration of different doses of nanocurcumin. Different organs were extracted for organ culture and histopathological investigation. Results: Based on the findings, 40 mg/kg of nanocurcumin significantly decreased the fungal load in the evaluated organs; the results were confirmed with histopathological examination. The kidney was found to be the most affected organ with the highest number of severe lesions. Yeasts and pseudohyphae were observed in the blood vessels, kidney, and brain. Also, yeasts were present in the liver, brain, lungs, and heart of the control group. Conclusion: Although curcumin is generally an excellent antifungal component, its nano-sized form showed more potent properties. Based on the gathered data, dendrosomal nanocurcumin is an effective antifungal agent with good efficacy against disseminated candidiasis. However, further studies are required to evaluate the effects of dendrosomal nanocurcumin on other fungal infections. Also, this agent could be useful for the prevention of fungal infections, such as candidiasis, particularly in high-risk patients

The sensitivity of the (1-3)-β-D-glucan (BDG) diagnostic test for candidemia varies in different clinical settings, and its usefulness in early diagnosis of candidemia is suboptimal. We evaluated the sensitivity of the test for early candidemia prediction. All adult patients with culture-proven candidemia who underwent a serum Goldstream Fungus (1-3)-β-D-Glucan Test within seven days prior to candidemia onset at a tertiary referral hospital between January 2017 and May 2021 were included. Any-positive BDG results within seven days prior to candidemia onset were obtained in 38 out of 93 (40.9%) patients. The positive rate increased when the test was performed near the day of candidemia onset ( P =0.04) but reached only 52% on the day of candidemia onset. We observed no significant differences between BDG-positive and -negative groups in terms of underlying disease, risk factors for candidemia, clinical presentation, origin of candidemia, and 30-day mortality. Candida albicans was significantly associated with positive BDG results than with all-negative BDG results ( P =0.04). The Goldstream BDG test is unreliable for candidemia prediction because of its low sensitivity. Negative BDG results in patients with a high risk of invasive candidiasis should be interpreted with caution.

The majority of immune components such as Toll-like receptor (TLR)-2, interleukin (IL)-17, neutrophils, and IL-10 play pivotal roles in immunity to Candida albicans ( C. albicans ) through identifying and launching inflammatory and regulatory responses. Chemotherapy is one of the most potent risk factors for systemic candidiasis through inducing immunosuppression (mostly cyclophosphamide induced immunosuppression) and there is a sensible lack of study around the immunity to C. albicans in such a situation. In this study, following the establishment of infection and immunosuppression in Balb/c mice model, the mRNA/protein levels of TLR-2, IL-10, IL-17, and Myeloperoxidase (MPO) in serum/kidney were measured using Real-time PCR and ELISA respectively. The survival of mice was checked daily and organ fungal burden was calculated and the histology samples were prepared. Results indicated that the mRNA and protein levels of IL-10, IL-17 and MPO were significantly elevated in immunosuppressed-infected mice ( P  < 0.05). Conversely, the mRNA level of TLR-2 in this mice were significantly decreased ( P  < 0.05). We conclude that, I. cyclophosphamide could induce only a minor state of immunosuppression through depletion of serum neutrophils. II. TLR-2 does not have important roles in developing immune responses in immunosuppressed mice model of systemic candidiasis. Our findings can be applicable for further experimental investigations on patients in clinics for deep understanding of pathogenesis of systemic candidiasis, which could be useful to further broaden our insights for targeted therapy, especially targeting TLR-2 and IL-17, based on siRNA, miRNA or monoclonal antibodies. [ABSTRACT FROM AUTHOR]

In an effort to increase the oral bioavailability of Amphotericin B (AmB), a pH-sensitive drug carrier composed of Tragacanth (Trag) and acrylic acid (AAc) was prepared using γ-irradiation. The swelling behavior of (Trag/AAc) hydrogels was characterized as a function of pH and ionic strength of the swelling medium. The obtained swelling indices revealed the ability of the prepared hydrogel to protect a loaded drug in stomach-simulated medium (Fickian behavior) and to release such drug in intestinal-simulated medium (non-Fickian behavior). In vitro release studies of the antifungal (AmB) were performed to evaluate the hydrogel potential as a drug carrier. The antifungal activity of the prepared oral formulation was investigated in a mouse model of systemic candidiasis. Data revealed that (Trag/AAc)-AmB has a potent antifungal efficacy as demonstrated by prolonging the survival time and reducing the tissue fungal burden, serum antibody titers, as well as inflammatory cytokines in kidney and liver tissues. Furthermore, in vivo toxicity of (Trag/AAc)-AmB was assessed via measuring kidney and liver functions, and results displayed the safety of this novel AmB formulation which was confirmed by histopathological examination. Overall, results indicated that the prepared (Trag/AAc)-AmB is an effective oral delivery system for AmB with better bioavailability and minimal toxicity and could represent a promising approach for improving the therapeutic index of the drug. [ABSTRACT FROM AUTHOR]

Systemic candidiasis is caused by Candida invading the bloodstream. The efficacy and safety of echinocandins in monotherapy and combination therapy regimes have not been adequately compared in immunocompromised patients with Candidiasis, and thus this systematic review aims to do so. A protocol was prepared a priori. PubMed, Embase and Cochrane Library databases were searched systematically (from inception of each database to September 2022) to identify randomized controlled trials. Two reviewers performed screening, quality assessment of trials, and extracted data independently. Pairwise meta-analysis was performed using random-effects model to compare echinocandin monotherapy versus other antifungals. The primary outcomes of interest were treatment success and treatment-related adverse events. 547 records (PubMed=310, EMBASE=210 and Cochrane Library=27) were reviewed. Following our screening criteria, six trials involving 177 patients were included. Risk of bias of four included studies had some concerns due to lack of a pre-specified analysis plan. Meta-analysis shows that echinocandin monotherapy does not have significantly higher rates of "treatment success" compared to other classes of antifungals (RR 1.12, 95%CI 0.80-1.56). However, echinocandins appeared to be significantly safer than other forms of antifungal therapy (RR 0.79, 95%CI 0.73-0.86). Our findings have shown that echinocandin monotherapy (micafungin, caspofungin) given intravenously are just as effective as other antifungals (amphotericin B, itraconazole) in the treatment of systemic candidiasis in immunocompromised patients. There appears to be similar benefits when using echinocandins compared to amphotericin B which has also been used as a broad-spectrum antifungal, while avoiding the severe adverse effects that amphotericin B causes, such as nephrotoxicity. [ABSTRACT FROM AUTHOR]

A 2-year-old male Mynah (Acridotheres tristis) was referred with history of abdominal hernia surgery, depression, cachexia, lethargy and swelling of foot joints. Hematological and biochemical findings consisted of leukocytosis, heterophilia, monocytosis, elevation of liver enzymes activity, hyperproteinemia and hyperglobulinemia. Fine needle aspiration (FNA) was performed from foot joints, aseptically. Mycological and bacteriological evaluations were shown Candida albicans infection. In spite of local and systemic treatments, signs were deteriorated and the animal was euthanized and then necropsy was done. Pathological findings revealed systemic candidiasis and fungal osteoarthritis.