Drug-resistant Fungi Research Articles

Applications of Nanotechnology in Combating Fungal Diseases in Humans: An Updated Review

In recent years, fungal infections caused by filamentous fungi have posed a serious threat to public health worldwide. Fungi such as Aspergillus, Coccidioides, and Mucorales (the most common filamentous fungi), as well as Candida auris (a non-filamentous fungus), can cause infections in humans. It can cause serious life-threatening diseases in individuals with weakened immune systems, patients infected with HIV/AIDS, uncontrolled diabetes, blood disorders, organ transplants, and chemotherapy. In this review, we describe the available nan formulations (metallic and polymeric nanoparticles) that have been developed to enhance efficacy and reduce the number of adverse effects following the administration of conventional antifungals. The burden posed by fungal infections on human health is increasing worldwide. Fungi such as Aspergillus, Candida, and Cryptococcus are among the most common pathogens responsible for human diseases, accounting for over 90% of infection-related deaths. Moreover, effective antifungal treatments are not available, primarily due to host toxicity, pathogen resistance, and immunodeficiency. In recent years, nanomaterials have proven to be not only more efficient antifungal therapeutic agents but also capable of overcoming fungal drug resistance".

Metal-antimicrobial peptides combo: promising weapons to combat bacteria invaders

Antimicrobial resistance has significantly increased over the last 30 years, prompting scientists to continuously look for novel, effective ways to combat drug-resistant bacteria and fungi. Due to their broad range of effectiveness, ease of synthesis, and ability to avoid resistance, antimicrobial peptides (AMPs) represent a potential approach. The direct investigation of metal effects on peptide activity has not received much attention. Divalent metal ions such as Zn(II), Cu(II), Ni(II), and Fe(II) do, in fact, influence some AMPs, producing an effect on their mode of action or function. Although the precise process by which metals are involved in microbial death is not well understood, this review goes into detail on several potential strategies to enhance AMPs activity through the synergy with metals. Important variables in these interactions include the individual peptide sequence, the type of metal ion, the capacity of metal to form chelates, and the softness of the ligand/metal complex. This article offers a thorough summary of the ways in which metal ions alter the structure of AMPs to boost their activity or sequester metal to impact on bacteria function.

Tissue-Compatible and Lubricated Hydrogel Catheter with Promising Activity Against Polymicrobial Infections for Ventilator-Associated Pneumonia Prevention.

Endotracheal intubation is a vital means of saving critically ill patients. However, the inserted catheter often causes tissue damage and the formation of tenacious biofilms containing drug-resistant bacteria and fungi, leading to severe ventilator-associated pneumonia (VAP). Currently, the resolution of VAP is usually based on antibiotic treatment and lacks targeted prophylaxis. Here, a quaternary phosphonium salts functionalized hydrogel catheter that enhances tissue compatibility yet inhibits complex and tenacious pathogens in the catheter, thus preventing VAP is reported. By copolymerizing the quaternary phosphonium electrolyte and acrylic acid monomers, the hydrogel catheter demonstrates good shape-supporting ability, and its strength and modulus can be adjusted over a wide range to meet the needs of different ages. Moreover, it possesses good tissue compatibility, antifouling properties, stable lubrication capability, and superior hydrophilicity, which may mitigate tissue damage caused by contact. Importantly, the hydrogel catheter demonstrates potent broad-spectrum intrinsic antimicrobial activity, eradicating nearly 99% of multi-drug resistant bacteria and 80% of fungi. To validate its role in preventing VAP, the real VAP pathogenesis process is mimicked, establishing a polymicrobial infections model considering time effects. The results prove that the hydrogel catheter effectively inhibits the invasion of various drug-resistant pathogens and prevents biofilm formation.

Discovery of highly potent triazole derivatives with broad-spectrum antifungal activity based on Iodiconazole

The widespread use of broad-spectrum antibiotics, the growing number of immunocompromised individuals, and the emergence of drug-resistant strains have resulted in the increasing incidence and mortality of invasive fungal infections. Azole drugs are the primary treatment for invasive fungal infections, and Iodiconazole is a potent azole drug with strong antifungal activity, but its stability is poor. In order to improve stability, a series of triazole compounds containing ethynyl group were designed and synthesized. Most of the compounds showed strong inhibitory activity against pathogenic fungi, among which compound 20l showed excellent inhibitory activity against pathogenic fungi and drug-resistant fungi. Importantly, and the stability of 20l (T1/2 = 30.2 min) was obviously improved compared with Iodiconazole (T1/2 = 4.39 min). In addition, the preferred compound 20l can prevent fungal phase transition and the formation of fungal biofilm, and show satisfactory fungicidal activity. In addition, the compound 20l was almost non-toxic to mammalian HUVEC cell and 293T cell. In vivo pharmacokinetic studies showed that 20l had acceptable pharmacokinetic properties. These results strongly demonstrate that compound 20l was worth further investigation as a potential antifungal inhibitor.

Oleanolic acid derivatives against drug-resistant bacteria and fungi by multi-targets to avoid drug resistance

Mixed infections caused by drug-resistant bacteria and fungi pose a severe threat to human health, and multi-target drugs may provide an effective approach to combat drug-resistant pathogens. Therefore, this study aimed to investigate the efficacies of some oleanolic acid (OA) derivatives against multidrug-resistant (MDR) bacteria and fungi using in vitro and in vivo experiments. Novel amphiphilic OA derivatives were designed and optimised, in which compounds G1 and J1 exhibited effective antimicrobial activity (MICs = 1–2 μg/mL), high selectivity against MDR strains, rapid bactericidal activity, and good predictive pharmacokinetics. Mechanistically, both compounds prevented drug resistance by disrupting the bacterial cell membrane, inserting into the DNA, and binding to DNA gyrase. Additionally, J1 reduced microbial count in a mouse MRSA skin infection model and accelerated wound healing much better than vancomycin. Conclusively, this study presents a new class of potential drugs for resistant bacteria and fungi.

Design and synthesis of spiro[pyrrolidine-3,3′-quinoline]-2,2′-dione derivatives as novel antifungal agents targeting chitin synthase

A novel spiro [pyrrolidine-3′,3′-quinoline]-2,2′-dione scaffold was constructed using fragments of quinoline and pyrrolidine. Subsequently, two series of derivatives were designed based on this scaffold. The enzyme inhibition experiments revealed that all designed compounds had moderate to good inhibitory activity against chitin synthase (CHS). The inhibitory effects of compounds 5i, 5j, 8i and 8n were approximately equal to that of control drug polyoxin B (PB, IP = 86.4 ± 2.9 %, IC50 = 0.082 ± 0.013 mM) which is a well-established CHS inhibitor. The results from enzyme kinetic parameters assays proved that these compounds act as non-competitive inhibitors of CHS. The sorbitol protection experiments demonstrated the tested compounds disrupted the synthesis of cell wall, which further verified that the target of these compounds is CHS. The experiments of antimicrobial showed that compounds 5b, 5f, 5i, 5j, 8f, 8i, 8m, 8n and 8o had strong antifungal activity against the four tested pathogenic fungi strains frequently emerging in clinical setting, with MIC values ranging from 4 to 32 μg/mL, which were either superior to or comparable with those of PB or fluconazole. Furthermore, these compounds displayed synergistic or additive effects when combined with fluconazole and these active compounds also showed promising activity against fluconazole-resistant and micafungin-resistant fungi variants. The result of antimicrobial experiments indicated that these compounds had minimal activity to tested bacterial strains. This suggests that they had selective antifungal activity. The results of ADME prediction, in conjunction with the cytotoxicity assay results, indicated that these compounds had favorable pharmacokinetic profiles and low toxicity. In addition, molecular docking studies illustrated that the compound had a strong affinity with the CHS, which was consistent with the results of enzymatic assays. These findings indicated that the designed compounds are non-competitive inhibitors of CHS with good selectivity and broad-spectrum antifungal activity, and possess significant antifungal activity against drug-resistant fungi, suggesting their potential as lead compounds for the development of novel drugs against drug-resistant fungi.

The Road Ahead: Advancing Antifungal Vaccines and Addressing Fungal Infections in the Post-COVID World.

In impoverished nations, the COVID-19 pandemic has led to a widespread occurrence of deadly fungal diseases like mucormycosis. The limited availability of effective antifungal treatments and the emergence of drug-resistant fungal strains further exacerbate the situation. Factors such as systemic steroid use, intravenous drug misuse, and overutilization of broad-spectrum antimicrobials contribute to the prevalence of hospital-acquired infections caused by drug-resistant fungi. Fungal infections exploit compromised immune status and employ intricate mechanisms to evade immune surveillance. The immune response involves the innate and adaptive immune systems, leading to phagocytic and complement-mediated elimination of fungi. However, resistance to antifungals poses a challenge, highlighting the importance of antifungal prophylaxis and therapeutic vaccination. Understanding the host-fungal immunological interactions and developing vaccines are vital in combating fungal infections. Further research is needed to address the high mortality and morbidity associated with multidrug-resistant fungal pathogens and to develop innovative treatment drugs and vaccines. This review focuses on the global epidemiological burden of fungal infections, host-fungal immunological interactions, recent advancements in vaccine development and the road ahead.

Synthesis of Graphene@C3N4-Cu Beads Nanocomposites and their Antimicrobial Efficacy Against Drug-Resistant Bacteria and Fungi.

Increased intake of drugs worldwide and the subsequent advent of resistance to existing antibiotics have globally threatened health organizations. To combat the problem of these drug-resistant infections, as an alternative approach, graphene (GN)-related nanomaterials have attracted significant interest because of their effective anti-microbial potential. The present study shows the synthesis and characterization of nanocomposite of GN with carbon nitride viz. g- C3N4, g-C3N4-Cu, and GN@g-C3N4-Cu. Further, we investigated the anti-microbial potential of these nanocomposites against strains of Gram-negative and Gram-positive bacteria, viz., a multidrug- resistant strain of Pseudomonas aeruginosa (MDRPA), a methicillin-resistant strain of Staphylococcus aureus ATCC33593 (MRSA), and an azole-sensitive fungal strain (Candida albicans ATCC14053). The morphological characterization of GN@g-C3N4-Cu nanocomposite was executed by scanning electron microscopy, whereas the elemental analysis and their distribution were studied by energy-dispersive X-ray spectroscopy and elemental mapping methods. Furthermore, the anti-microbial and antibiofilm efficacies of g-C3N4, g-C3N4-Cu, and GN@g-C3N4-Cu nanocomposites were evaluated by disc diffusion, two-fold serial micro broth dilution, and 96 well microtiter plate methods. The ternary g-C3N4-Cu@GN, apart from the structures of g-C3N4-Cu, showed big sheets of GN. The observance of C, N, O, and Cu in the elemental analysis, as well as their uniform distribution in the mapping, indicated the successful fabrication of g-C3N4-Cu@GN. GN@g-C3N4-Cu followed by g-C3N4-Cu and (g-C3N4) exhibited significantly higher antimicrobial activity (zone of inhibition from 14.33 to 49.33 mm) against both the drug-resistant bacterial strains and azole-sensitive C. albicans. MICs of nanocomposites ranged from 32 -256 μg/ml against the tested strains. Whereas all three nanocomposites at sub-MICs (0.25 A- and 0.5 A- MICs) showed concentration- dependent inhibition of biofilm formation in MDRPA, MRSA, and C. albicans by allowing 11.35% to 32.59% biofilm formation. Our study highlights the enhanced efficiency of GN@g-C3N4-Cu nanocomposites as potential anti-microbial and antibiofilm agents to overcome the challenges of multi-drug-resistant bacteria and azole-sensitive fungi. Such kind of nanocomposites could be used to prevent nosocomial infections if coated on medical devices and food manufacturing instruments.

Recent Advances in Marine-Derived Compounds as Potent Antibacterial and Antifungal Agents: A Comprehensive Review.

The increase in antimicrobial resistance (AMR) in microorganisms is a significant global health concern. Various factors contribute to AMR, including alterations in cell membrane permeability, increased efflux pump activity, enzymatic modification or inactivation of antibiotics, target site changes, alternative metabolic pathways, and biofilm formation. Marine environments, with their extensive biodiversity, provide a valuable source of natural products with a wide range of biological activities. Marine-derived antimicrobial compounds show significant potential against drug-resistant bacteria and fungi. This review discusses the current knowledge on marine natural products such as microorganisms, sponges, tunicates and mollusks with antibacterial and antifungal properties effective against drug-resistant microorganisms and their ecological roles. These natural products are classified based on their chemical structures, such as alkaloids, amino acids, peptides, polyketides, naphthoquinones, terpenoids, and polysaccharides. Although still in preclinical studies, these agents demonstrate promising in vivo efficacy, suggesting that marine sources could be pivotal in developing new drugs to combat AMR, thereby fulfilling an essential medical need. This review highlights the ongoing importance of marine biodiversity exploration for discovering potential antimicrobial agents.

Unsaturated fatty acid perturbation combats emerging triazole antifungal resistance in the human fungal pathogen Aspergillus fumigatus.

Contemporary antifungal therapies utilized to treat filamentous fungal infections are inhibited by intrinsic and emerging drug resistance. Consequently, there is an urgent need to develop novel antifungal compounds that are effective against drug-resistant filamentous fungi. Here, we utilized an Aspergillus fumigatus cell-based high-throughput screen to identify small molecules with antifungal activity that also potentiated triazole activity. The screen identified 16 hits with promising activity against A. fumigatus. A nonspirocyclic piperidine, herein named MBX-7591, exhibited synergy with triazole antifungal drugs and activity against pan-azole-resistant A. fumigatus isolates. MBX-7591 has additional potent activity against Rhizopus species and CO2-dependent activity against Cryptococcus neoformans. Chemical, genetic, and biochemical mode of action analyses revealed that MBX-7591 increases cell membrane saturation by decreasing oleic acid content. MBX-7591 has low toxicity in vivo and shows good efficacy in decreasing fungal burden in a murine model of invasive pulmonary aspergillosis. Taken together, our results suggest MBX-7591 is a promising hit with a novel mode of action for further antifungal drug development to combat the rising incidence of triazole-resistant filamentous fungal infections.IMPORTANCEThe incidence of infections caused by fungi continues to increase with advances in medical therapies. Unfortunately, antifungal drug development has not kept pace with the incidence and importance of fungal infections, with only three major classes of antifungal drugs currently available for use in the clinic. Filamentous fungi, also called molds, are particularly recalcitrant to contemporary antifungal therapies. Here, a recently developed Aspergillus fumigatus cell reporter strain was utilized to conduct a high-throughput screen to identify small molecules with antifungal activity. An emphasis was placed on small molecules that potentiated the activity of contemporary triazole antifungals and led to the discovery of MBX-7591. MBX-7591 potentiates triazole activity against drug-resistant molds such as A. fumigatus and has activity against Mucorales fungi. MBX-7591's mode of action involves inhibiting the conversion of saturated to unsaturated fatty acids, thereby impacting fungal membrane integrity. MBX-7591 is a novel small molecule with antifungal activity poised for lead development.

The critical roles of the Zn2Cys6 transcription factor Fp487 in the development and virulence of Fusarium pseudograminearum: A potential target for Fusarium crown rot control

Fusarium crown rot (FCR) caused by Fusarium pseudograminearum poses a significant threat to wheat production in the Huang-Huai-Hai region of China. However, the pathogenic mechanism of F. pseudograminearum is still poorly understood. Zn2Cys6 transcription factors, which are exclusive to fungi, play pivotal roles in regulating fungal development, drug resistance, pathogenicity, and secondary metabolism. In this study, we present the functional characterization of a Zn2Cys6 transcription factor F. pseudograminearum, designated Fp487. In F. pseudograminearum, Fp487 is shown to be required for mycelial growth through gene knockout and phenotypic analyses. Compared with wild-type CF14047, the ∆Fp487 mutant displayed a slight reduction in growth rate but a significant decrease in conidiogenesis, pathogenicity and 3-acetyl-deoxynivalenol (3AcDON) production. Moreover, the mutant exhibited heightened sensitivity to oxidative and cytomembrane stress. Furthermore, we synthesized dsRNA from the Fp487 gene in vitro, resulting in a reduction in the growth rate of F. pseudograminearum and its virulence on barley leaves through spray-induced gene silencing (SIGS). Notably, this study makes the first instance of inducing the expression of abundant dsRNA from F. pseudograminearum by engineering the Escherichia coli strain HT115 (DE3) and utilizing the SIGS technique to evaluate the virulence effect of dsRNA on F. pseudograminearum. In conclusion, our findings revealed the crucial role of Fp487 in regulating pathogenicity, stress responses, DON production, and conidiogenesis in F. pseudograminearum. Furthermore, Fp487 is a potential RNAi-based target for FCR control.

Gamma-Rays Empowered the Antimicrobial Potential of TiO2/Fe3O4/MIL-101(Cr) Nanocomposite against Drug-Resistant Bacteria and Pathogenic Fungi

Gamma-Rays Empowered the Antimicrobial Potential of TiO2/Fe3O4/MIL-101(Cr) Nanocomposite against Drug-Resistant Bacteria and Pathogenic Fungi

Construction and Activity Evaluation of Novel Bifunctional Inhibitors and a COF Carrier Based on a Fungal Infection Microenvironment.

Faced with increasingly serious fungal infections and drug resistance issues, three different series of novel dual-target (programmed death ligand 1/14 α-demethylase) compounds were constructed through the fragment combination pathway in the study. Their chemical structures were synthesized, characterized, and evaluated. Among them, preferred compounds 10c-1, 17b-1, and 18b-2 could efficiently exert their antifungal and antidrug-resistant fungal ability through blocking ergosterol biosynthesis, inducing the upregulation of reactive oxygen species level, and triggering apoptosis. Especially, compound 18b-2 exhibited the synergistic function of fungal inhibition and immune activation. Moreover, the covalent organic framework carrier was also generated based on the acidic microenvironment of fungal infection to improve the bioavailability and targeting of preferred compounds; this finally accelerated the body's recovery rate.

The clinical value of mNGS of bronchoalveolar lavage fluid versus traditional microbiological tests for pathogen identification and prognosis of severe pneumonia (NT-BALF):study protocol for a prospective multi-center randomized clinical trial.

Early, rapid, and accurate pathogen diagnosis can help clinicians select targeted treatment options, thus improving prognosis and reducing mortality rates of severe pneumonia. Metagenomic next-generation sequencing (mNGS) has a higher sensitivity and broader pathogen spectrum than traditional microbiological tests. However, the effects of mNGS-based antimicrobial treatment procedures on clinical outcomes and cost-effectiveness in patients with severe pneumonia have not been evaluated. This is a regional, multi-center, open, prospective, randomized controlled trial to evaluate that whether the combination of mNGS and traditional testing methods could decrease 28-day call-cause mortality with moderate cost-effectiveness. A total of 192 patients with severe pneumonia will be recruited from four large tertiary hospitals in China. Bronchoalveolar lavage fluid will be obtained in all patients and randomly assigned to the study group (mNGS combined with traditional microbiological tests) or the control group (traditional microbiological tests only) in a 1:1 ratio. Individualized antimicrobial treatment and strategy will be selected according to the analysis results. The primary outcome is 28-day all-cause mortality. The secondary outcomes are ICU and hospital length of stay (LOS), ventilator-free days and ICU-free days, consistency between mNGS and traditional microbiological tests, detective rate of mNGS and traditional microbiological tests, turn-out time, time from group allocation to start of treatment, duration of vasopressor support, types and duration of anti-infective regimens, source of drug-resistant bacteria or fungi, and ICU cost. The clinical benefits of mNGS are potentially significant, but its limitations should also be considered. ChineseClinicalTrialRegistry.org, ChiCTR2300076853. Registered on 22 October 2023.

Antifungal drug discovery for targeting Candida albicans morphogenesis through structural dynamics study

In response to the escalating threat of drug-resistant fungi to human health, there is an urgent need for innovative strategies. Our focus is on addressing this challenge by exploring a previously untapped target, yeast casein kinase (Yck2), as a potential space for antifungal development. To identify promising antifungal candidates, we conducted a thorough screening of the diverse-lib drug-like molecule library, comprising 99,288 molecules. Five notable drug-like compounds with diverse-lib IDs 24334243, 24342416, 17516746, 17407455, and 24360740 were selected based on their binding energy scores surpassing 11 Kcal/mol. Our investigation delved into the interaction studies and dynamic stability of these compounds. Remarkably, all selected molecules demonstrated acceptable RMSD values during the 200 ns simulation, indicating their stable nature. Further analysis through Principal Component Analysis (PCA)-based Free Energy Landscape (FEL) revealed minimal energy transitions for most compounds, signifying dynamic stability. Notably, the two compounds exhibited slightly different behaviour in terms of energy transitions. These findings mark a significant breakthrough in the realm of antifungal drugs against C. albicans by targeting the Yck2 protein. However, it is crucial to note that additional experimental validation is imperative to assess the efficacy of these molecules as potential antifungal candidates. This study serves as a promising starting point for further exploration and development in the quest for effective antifungal solutions. Communicated by Ramaswamy H. Sarma

Drug Design: Do Not Forget the Supramolecular Factor.

A major challenge currently facing medicinal chemists is designing agents that can selectively destroy drug resistant fungi and bacteria that have begun to emerge. One factor that has been overlooked by virtually all drug discovery/development approaches is the supramolecular factor, in which aggregated forms of a drug candidate exhibit low selectivity in destroying targeted cells while the corresponding monomers exhibit high selectivity. This Perspective discusses how we were led to the supramolecular factor through fundamental studies with simple model systems, how we reasoned that the selectivity of monomers of the antifungal agent amphotericin B should be much greater than the selectivity of the corresponding aggregates, and how we confirmed this hypothesis using derivatives of amphotericin B. In a broader context, these findings provide a strong rationale for considering the supramolecular factor in the design of new drug candidates and the testing of virtually all of them.

Poacic Acid, a Plant-Derived Stilbenoid, Augments Cell Wall Chitin Production, but Its Antifungal Activity Is Hindered by This Polysaccharide and by Fungal Essential Metals.

Climate and environmental changes have modified the habitats of fungal pathogens, inflicting devastating effects on livestock and crop production. Additionally, drug-resistant fungi are increasing worldwide, driving the urgent need to identify new molecular scaffolds for the development of antifungal agents for humans, animals, and plants. Poacic acid (PA), a plant-derived stilbenoid, was recently discovered to be a novel molecular scaffold that inhibits the growth of several fungi. Its antifungal activity has been associated with perturbation of the production/assembly of the fungal cell wall β-1,3-glucan, but its mode of action is not resolved. In this study, we investigated the antifungal activity of PA and its derivatives on a panel of yeast. PA had a fungistatic effect on S. cerevisiae and a fungicidal effect on plasma membrane-damaged Candida albicans mutants. Live cell fluorescence microscopy experiments revealed that PA increases chitin production and modifies its cell wall distribution. Chitin production and cell growth returned to normal after prolonged incubation. The antifungal activity of PA was reduced in the presence of exogenous chitin, suggesting that the potentiation of chitin production is a stress response that helps the yeast cell overcome the effect of this antifungal stilbenoid. Growth inhibition was also reduced by metal ions, indicating that PA affects the metal homeostasis. These findings suggest that PA has a complex antifungal mechanism of action that involves perturbation of the cell wall β-1,3-glucan production/assembly, chitin production, and metal homeostasis.

Hsp90-Mediated Multi-Drug Resistance in DNA Polymerase-Defective Strains of Candida albicans.

The incidence of infections caused by Candida species, specifically by drug-resistant isolates, is a major health concern as they can disseminate to and colonize most vital organs, enhancing morbidity and mortality. Several molecular mechanisms have been reported to be involved in drug resistance. These are mostly drug- and isolate-specific. Here, we characterized three different genetically modified strains of C. albicans that were multi-drug-resistant (MDR) and deciphered a uniform mechanism responsible for resistance. DNA polymerase epsilon (Polε) is a leading strand-specific polymerase consisting of four subunits, namely, Pol2, Dpb2, Dpb3, and Dpb4. The deletion of one or both of the Dpb3 and Dpb4 subunits in C. albicans rendered multi-drug resistance. A detailed characterization of these strains revealed that acquired mutagenesis, drug efflux pumps, and other known mechanisms did not play a significant role because the complemented strain showed drug sensitivity. More importantly, the function of heat shock protein 90 (Hsp90) in these knockout strains is critical for reducing susceptibility to several antifungal drugs. Cell wall deformity and composition in these strains can add to such a phenotype. The inhibition of Hsp90 function by geldanamycin and tricostatin A sensitized the MDR strains to antifungals. Considering our earlier research and this report, we suggest that replication stress induces Hsp90 expression and activity in order to orchestrate a cellular stress response circuit and thus develop fungal drug resistance. Thus, Hsp90 is an important drug target for use in combinatorial therapy.

Antifungal Potential of Bioactive Metabolites Produced by Pseudomonas aeruginosa against Candida Species

Abstract: Background: The frequency of fungal infections targeting immune-suppressed patients has been prominently rising day by day. Among these infections, Candidiasis is one of the most common life-threatening systemic fungal infections in recent years. These infections are challenging to treat because of the inconvenience of effective antifungal drugs. Therefore, the insufficiency of current drug regimens coupled with constant mutations by the fungi to develop drug resistance can pose a potential problem for future anti-fungal treatments. This frequent increase in drug-resistant fungi has directed attention toward the use of alternative therapy from natural sources. Objective: This study aimed to evaluate Pseudomonas aeruginosa for its antifungal potential against Candida species. Materials and Methods: This study was conducted at the Federal Urdu University of Arts, Science and Technology, Karachi, Pakistan during 2021-2022. For the detection of the antifungal compound, a clinical isolate P. aeruginosa HS 28 (identified conventionally as well as by 16S r RNA analysis) was screened for its bioactivity against Candida species by using agar well diffusion technique. The growth kinetics as well as the effect of different physical and chemical factors were also determined in the study. The compound was also partially purified by ammonium sulfate precipitation. Result: This antifungal compound showed good inhibitory activity against Candida species such as Candida albicans, C. glabrata, C. tropicalis, C. krusei, etc. This compound retained its stability at a high range of temperatures, and varying pH. Moreover, its bioactivity was also conserved when treated with organic solvents, chloroform vapors, metal salts, and different surfactants/detergents. The growth kinetics analysis illustrated that the maximum production of antifungal compounds occurred in the log phase of growth and extended supreme until the late log phase. Furthermore, the highest saturation of this protein was achieved at the concentration of 60% ammonium sulfate. Conclusion: The overall results indicated the promising antifungal potential of the compound produced by Pseudomonas aeruginosa HS 28 against Candida species.

Borneol serves as an adjuvant agent to promote the cellular uptake of curcumin for enhancing its photodynamic fungicidal efficacy against Candida albicans

Candida albicans (C. albicans), a major opportunistic pathogenic fungus, is known to cause superficial skin infections. Unfortunately, the misuse of antibiotics has led to the emergence of drug resistance in fungi. Antimicrobial photodynamic therapy (aPDT), a non-antibiotic alternative, has shown potential in treating drug-resistant fungal infections. Curcumin is a photodynamically active phytochemical whose photodynamic fungicidal efficacy is largely dependent on its intracellular accumulation. However, curcumin faces challenges in penetrating the cytoplasm due to its poor water solubility and the fungal cell wall. Borneol, another monoterpenoid phytochemical, is known for its ability to enhance drug absorption. In this study, we showed that borneol improved the cellular uptake of curcumin, thereby enhancing its photodynamic fungicidal efficacy against C. albicans. This effect was attributed to borneol's ability to increase cell permeability. Transcriptomic analysis further confirmed that borneol disrupted the normal structure and function of the C. albicans cell wall and membrane, resulting in dysregulated mRNA expression of related genes and ultimately increased cell permeability. As a result, the excessive accumulation of curcumin in C. albicans triggered the overproduction of intracellular ROS upon exposure to blue light. These excessive intracellular ROS disrupted various cellular structures, interfered with essential cellular processes, inhibited biofilm formation and reduced virulence. Remarkably, borneol was also found to enhance curcumin uptake by C. albicans within biofilms, further enhancing the anti-biofilm efficacy of curcumin-mediated aPDT (Cur-aPDT). In conclusion, the results of this study strongly support the potential of borneol as an adjuvant agent to Cur-aPDT in treating superficial cutaneous fungal infections.