Primary cutaneous cryptococcosis (PCC) is a rare infection caused by direct inoculation of Cryptococcus through disrupted skin. We report a 52-year-old male farmer with type 2 diabetes but no HIV infection or known major immunosuppressive disease who developed chronic refractory ulcers on the right forearm following suspected insect-bite trauma. Cryptococcus neoformans was isolated from cutaneous specimens. Probe-capture metagenomic next-generation sequencing (MetaCAP) of the ulcer tissue additionally detected C. neoformans at 202 reads per million (RPM), accounting for 91.98% of the fungal sequences, with a reported confidence of 99%. Histopathology demonstrated an infectious granuloma, while bacterial culture identified methicillin-resistant Staphylococcus aureus and extended-spectrum β-lactamase-producing Escherichia coli. Chest computed tomography and cerebrospinal fluid investigations did not support pulmonary or central nervous system cryptococcosis. Liposomal amphotericin B was discontinued because of acute kidney injury, and subsequent fluconazole plus flucytosine treatment resulted in reduced exudation, granulation tissue formation, and partial ulcer healing. PCC should be considered in chronic post-traumatic ulcers, with systematic evaluation for extracutaneous involvement before establishing a primary cutaneous diagnosis.

Invasive fungal infections are a major global health threat, contributing substantially to morbidity and mortality, particularly in immunocompromised populations. Despite the availability of four major antifungal drug classes-azoles, polyenes, echinocandins, and flucytosine-current therapies remain constrained by dose-limiting toxicity, suboptimal pharmacokinetics, and the emergence of multidrug resistance. This review critically evaluates formulation-driven strategies to optimize the therapeutic performance of existing antifungal drugs. It discusses the biological, biopharmaceutical, and clinical barriers that limit treatment outcomes and the formulation approaches developed to overcome these challenges. Particular emphasis is placed on nanotechnology-based drug delivery systems, biofilm-targeting strategies, stimuli-responsive platforms, and combination therapies. The review further highlights the emerging role of artificial intelligence (AI)-driven formulation design, predictive modeling, and precision therapeutics in advancing antifungal treatment. The integration of nanotechnology, AI-driven computational modeling, and precision therapeutics offers new opportunities to improve efficacy, reduce toxicity, and enable more personalized antifungal treatment. Together, these advances position formulation science as a key driver of innovation in next generation of antifungal therapy.

We report a case of a man in his early 40s living with stable HIV and receiving continuous antiretroviral therapy (ART) who presented with transient binocular diplopia and areflexia. Neuroimaging was unrevealing, but lumbar puncture demonstrated elevated opening pressure, lymphocytic pleocytosis, the presence of cryptococcal antigen and growth of Cryptococcus neoformans Additional testing disclosed detectable cerebrospinal fluid (CSF) HIV RNA despite serum viral suppression. He was diagnosed with cryptococcal meningitis; CSF revealed HIV escape. He was treated with amphotericin B and flucytosine followed by fluconazole with parallel intensification of ART to improve central nervous system (CNS) penetration. Neurological symptoms, including diplopia and areflexia, resolved with this combined therapy. This case highlights that subtle transient visual symptoms may herald cryptococcal meningitis, perhaps from sequelae of elevated intracranial pressure. CSF HIV escape should be considered in patients with progressive CNS disease despite control of HIV viral load and CD4 cell counts over 400 cells/µL.

Achieving tumor-specific delivery and sustained activation of both cytotoxic and immune-modulating agents remains a critical challenge in chemoimmunotherapy. Here, a bacterial platform was engineered to combine enzyme/prodrug chemotherapy with immunotherapy, in which tumor-homing Escherichia coli Nissle 1917 expressed cytosine deaminase to convert the prodrug 5-fluorocytosine into the cytotoxic drug 5-fluorouracil and concurrently produced an IL-15 superagonist and a PD-L1 blocking nanobody in tumors. This platform demonstrated potent antitumor effects in murine MC38 and B16-F10 solid tumor models. Mechanistic analyses showed that bacterial enzyme/prodrug therapy alone elicited both immune activation and compensatory immunosuppressive responses, whereas inclusion of IL-15 superagonist and PD-L1 blockade enhanced activation of antigen-presenting cells, T cells, and natural killer cells and attenuated immunosuppressive pathways. Abscopal and rechallenge experiments indicated that this bacterial chemoimmunotherapy strategy induces systemic antitumor immunity and durable immune memory. In summary, our approach integrates enzyme/prodrug therapy and immunotherapy into a single bacterial delivery system, overcoming key limitations of conventional therapies by providing a rationally designed framework for spatially controlled chemoimmunotherapy.

Candidozyma auris is an emerging healthcare-associated fungal pathogen with a high propensity for nosocomial transmission and development of antifungal resistance. This study aimed to identify resistance-associated genomic variants and characterize the phylogenetic structure of clinical C. auris isolates circulating in Russia.

Disseminated cryptococcosis is a rare but serious opportunistic infection following solid organ transplantation and rarely occurs within the first month of transplantation. We report a case of disseminated Cryptococcus neoformans infection occurring 14 days after orthotopic heart transplantation which required mechanical circulatory support with venoarterial extracorporeal membrane oxygenation (VA-ECMO). Management was complicated by alterations in antifungal pharmacokinetics and the inability to perform serial lumbar punctures while anticoagulated. Antifungal therapy with nonliposomal amphotericin B, flucytosine, and fluconazole was administered. A combination of optic nerve sheath diameter measurements, CT scans, and evaluation for papilledema was used as temporizing, noninvasive surrogates for intracranial pressure monitoring until lumbar punctures could be safely performed. The patient was successfully decannulated, weaned from mechanical support, and discharged from the intensive care unit.

Flucytosine-induced colitis is exceedingly rare with very few cases reported in the literature. We present a case of a 56-year-old male with history of ulcerative colitis and seronegative spondyloarthropathy who developed abdominal pain, diarrhoea and rectal bleeding following commencement of flucytosine and amphotericin B for cryptococcal empyema. The clinical features and biochemistry initially raised concern for an ulcerative colitis flare. Histopathology demonstrated features of an acute colitis. Subsequent cessation of flucytosine without alteration to management of his underlying ulcerative colitis led to a rapid and complete resolution of symptoms, supporting a diagnosis of flucytosine-induced colitis. This case highlights the importance of considering a drug-induced colitis in patients with inflammatory bowel disease presenting with new or worsening gastrointestinal symptoms. Accurate differentiation from disease flare is essential to avoid unnecessary changes or escalation in immunosuppressive therapy.

Purpureocillium lilacinum, a common environmental fungus, can cause hyalohyphomycosis with varied clinical manifestations. Mortality rates can reach 20% with invasive disease. P. lilacinum is intrinsically resistant to amphotericin B, leaving few treatment options. In the absence of clinical breakpoints, epidemiological cutoff values (ECVs) can aid clinicians in monitoring antifungal resistance trends and in guiding initial therapy. We performed antifungal susceptibility testing (AFST) on P. lilacinum isolates to establish minimum inhibitory concentration (MIC) and minimum effective concentration (MEC) distributions and ECVs. Data were collected from 13 laboratories located in seven countries. AFST was performed by broth microdilution (CLSI M38 standard) for itraconazole, voriconazole, posaconazole, isavuconazole, terbinafine, flucytosine, amphotericin B, natamycin, and manogepix. ECVs were established using the iterative statistical method with ECOFFinder (v2.1) following CLSI M57 guidelines. Results from 479 P. lilacinum isolates were analyzed. ECVs were 1 μg/mL for voriconazole, 2 μg/mL for posaconazole, 4 μg/mL for isavuconazole, and 2 μg/mL for terbinafine. Itraconazole displayed a trimodal MIC distribution, although almost all MICs were ≥0.5 µg/mL (mode, 16 μg/mL). Amphotericin B, natamycin, and flucytosine MICs were truncated at the high end of the range and consistent with intrinsic resistance. The manogepix modal MEC was 0.008 μg/mL. These proposed P. lilacinum ECVs and MIC/MEC distributions provide baseline data to monitor resistance trends. Our results confirm that P. lilacinum is intrinsically resistant (IR) to amphotericin B and likely IR to natamycin and flucytosine. Caution is needed in interpreting itraconazole results due to high interlaboratory variability.IMPORTANCEPurpureocillium lilacinum is a hyaline mold commonly found in the environment and used as an agricultural biopesticide. Infections caused by P. lilacinum can range from fungal eye infections to life-threatening pulmonary and disseminated disease, and mortality rates can be high (up to 20%). Single-center studies examining antifungal susceptibility testing (AFST) data found reduced susceptibility to certain antifungals, but more robust global AFST studies are needed to help interpret MICs and MECs. We performed AFST according to the Clinical Laboratory and Standards Institute reference method in thirteen independent laboratories on 479 P. lilacinum isolates to establish MIC/MEC distributions and epidemiological cutoff values (ECVs) for nine antifungals, including those recommended by global treatment guidelines. The calculated ECVs were 1 μg/mL for voriconazole, 2 μg/mL for posaconazole, 4 μg/mL for isavuconazole, and 2 μg/mL for terbinafine. Our results also confirm that P. lilacinum is intrinsically resistant to amphotericin B and likely intrinsically resistant to natamycin and flucytosine. Caution is needed in interpreting itraconazole AFST results due to high interlaboratory variability. These antifungal in vitro susceptibility data suggest limited options to treat P. lilacinum infections.

Cryptococcosis is a major health threat among immunocompromised individuals, resulting in life-threatening consequences secondary to brain invasion. The limited treatment options and the increased incidence of treatment failure and relapses urge the need for more effective therapies. In this study, we investigated the therapeutic potential of nitroxoline (NTX) in treating cryptococcal infection. NTX exhibited potent fungicidal activity against Cryptococcus neoformans/gattii clinical isolates, with an MIC90 of 1 µg/mL. In addition, NTX substantially inhibits the main virulence traits of cryptococcal cells, including the polysaccharide capsule, melanin production, and the urease enzyme, which are crucial for the infection progression. In exploring the potential mechanism of action, our results revealed the relationship between the metal-chelating properties of the NTX scaffold and its antifungal activity. Interfering metal chelation, either through structural modification or exogenous supplementation with varied divalent cations, significantly reduced the antifungal and anti-virulence activities of NTX. Given its potential therapeutic role, we evaluated the interaction between NTX and the clinically used antifungals amphotericin B, flucytosine and fluconazole. Additionally, we investigated the tendency of cryptococcal cells to develop resistance following repeated exposure to NTX, as well as its efficacy in the Caenorhabditis elegans nematode model of cryptococcal infection. Notably, cryptococcal cells exhibited consistent susceptibility to NTX upon repeated exposure to a subinhibitory concentration. In the C. elegans model, NTX significantly reduced the fungal burden of the infected worms, achieving a 2-log10 reduction, and consistently enhanced their survival compared to untreated group. These findings highlight the potential role of the NTX scaffold in combating cryptococcal infection that warrants further investigation.