Fungal infections in Asia are influenced by warm, humid climates, high population density and expanding healthcare systems, which together facilitate the emergence, transmission and detection of both common and rare pathogens. While Candida and Aspergillus species remain the leading causes of invasive fungal disease, increasing attention has focused on uncommon yeasts and rare moulds, many of which show intrinsic or acquired antifungal resistance. Advances in molecular diagnostics and susceptibility testing have improved identification of emerging pathogens, including uncommon Candida species and rare moulds such as Mucorales, filamentous Basidiomycetes, non-marneffei Talaromyces, Oomycetes and thermally dimorphic fungi like Emergomyces. These organisms primarily affect immunocompromised individuals and present significant diagnostic and therapeutic challenges due to identification difficulties, variable susceptibility patterns and limited clinical experience. Clinical presentations range from fungaemia and invasive pulmonary disease to cutaneous and disseminated infections. Treatment is guided by pathogen and susceptibility profiles, commonly involving echinocandins, amphotericin B and azoles. In some cases, particularly infections caused by Oomycetes and Mucorales, prompt surgical intervention is essential. This review provides a comprehensive overview of current epidemiological trends, risk factors, clinical features, antifungal susceptibility patterns and treatment outcomes associated with rare and emerging fungal pathogens in Asia. By highlighting these increasingly recognized infections, it aims to enhance awareness among clinicians and mycologists, promote evidence-based diagnostic and therapeutic approaches and inform future research addressing this evolving and clinically significant public health challenge.
BACKGROUND:Fusarium spp. are clinically relevant filamentous fungi with intrinsically low susceptibility to multiple antifungal agents, particularly azoles, and are included in the World Health Organization fungal priority pathogens list. OBJECTIVES:To investigate azole resistance-related mechanisms in clinical isolates belonging to the Fusarium solani species complex (FSSC), Fusarium oxysporum species complex (FOSC) and Fusarium fujikuroi species complex (FFSC) recovered in São Paulo, Brazil. METHODS:Twenty-six clinical isolates were identified by sequencing of the ITS region, TEF1 and RPB2. Antifungal susceptibility testing, CYP51A amplification and sequencing and expression analysis of CYP51A and ABC1 under voriconazole exposure were performed. RESULTS:Antifungal susceptibility testing showed broadly elevated azole MICs, with the FSSC displaying the least favourable profile. Comparative CYP51A analysis revealed distinct amino acid signatures among the three species complexes, including residues at positions equivalent to canonical azole resistance hotspots in Aspergillus fumigatus. However, no simple relationship was observed between CYP51A amino acid profiles and azole MIC values. In contrast, voriconazole exposure induced marked CYP51A upregulation in all tested isolates, with substantially higher expression in the higher-MIC FSSC isolate. ABC1 was also upregulated in FSSC isolates, although at markedly lower levels than CYP51A. CONCLUSIONS:These findings support a multifactorial model of azole response in Fusarium species complex strains, involving conserved CYP51A sequence features, strong target-gene induction under antifungal stress, and a lower but detectable contribution of efflux-associated mechanisms.
BACKGROUND:Opportunistic yeasts account for a substantial proportion of invasive fungal infections and are important agents of healthcare-associated infections, especially in intensive care units (ICUs). OBJECTIVES:To describe the clinical and epidemiological characteristics of hospitalized patients with positive cultures for medically relevant yeasts and correlate these data with antifungal susceptibility, biocide tolerance and phenotypic efflux pump activity. METHODS:Ninety-four clinical isolates were analysed: 31 Trichosporon asahii, 39 Candida albicans and 24 other yeasts. Antifungal susceptibility and biocide tolerance were assessed by disk diffusion, and phenotypic efflux pump activity was evaluated using ethidium bromide. Clinical and epidemiological data were retrieved from electronic health records. RESULTS:Most isolates (73.4%) originated from ICUs. Urine (55.3%) was the most frequent clinical specimen. Overall mortality was 62.7%, reaching 71.8% among patients with C. albicans. Notably, 68.1% of patients did not receive antifungal therapy after diagnosis. All T. asahii isolates were susceptible to azoles and resistant to caspofungin. C. albicans showed high susceptibility to amphotericin B (100%) and caspofungin (93%). Phenotypic efflux pump activity was observed in all evaluated yeasts. Sodium hypochlorite showed greater antifungal activity, with inhibition zones of up to 18.0 mm, while hydrogen peroxide (4.25%) and benzalkonium chloride (5%) showed minimal zones (~6 mm) for all isolates. CONCLUSIONS:Opportunistic yeast infections continue to pose a major challenge in healthcare settings. Our findings highlight the critical importance of accurate laboratory identification, ongoing surveillance of antifungal susceptibility, and effective infection prevention and control strategies, including the rational selection of biocides, to improve patient outcomes.
BACKGROUND:Candidaemia remains a common, life-threatening infection among intensive care unit (ICU) patients, with high mortality, particularly in patients with delayed diagnosis and treatment. OBJECTIVES:This international, multicentre, prospective, observational study aimed to identify risk factors for candidaemia in ICU patients and to develop an easy-to-use predictive tool, the CanDi-Score, for early initiation of empirical antifungal treatment. PATIENTS/METHODS:All adults over 18 years hospitalised for more than 48 h in the ICUs were included in the study and followed for 30 days. Data on demographics, comorbidities, clinical severity scores including APACHE II and SOFA scores, Charlson comorbidity index (CCI), established risk factors for candidaemia and their time-dependent effects such as total parenteral nutrition (TPN), mechanical ventilation (MV), and central venous catheter (CVC) were collected. Univariate and multivariate logistic regression analyses were used to identify factors associated with candidaemia development, and fast backwards variable selection was used. To account for between-centre heterogeneity, sensitivity analyses were performed using mixed-effects logistic regression models including centre-specific random intercepts. A nomogram model was constructed using independent risk factors identified in multivariable analysis, and its predictive performance was evaluated with Area Under the Curve (AUC), sensitivity, and specificity. RESULTS:A total of 2,704 ICU patients, including 204 with candidaemia, were enrolled. Patients with candidaemia had higher APACHE II (19 vs. 13) and CCI scores (6 vs. 5; both p < 0.001), and more frequently had chronic renal failure, haemodialysis, malignancy, recent gastrointestinal surgery, and neutropenia (all p ≤ 0.05). Patients were randomly split into development (80%) and validation (20%) cohorts. Multivariate analysis identified higher CCI, concurrent infection, neutropenia, ICU stay > 14 days, MV > 3 days, CVC duration and TPN > 14 days as independent risk factors. The risk associated with CVC increased substantially with prolonged use (OR: 0-7 days: 3.69; 8-21 days: 8.58; > 21 days: 17.21). The model demonstrated good performance in both the development and validation cohorts, with sensitivity, specificity, and AUC values of 79.6%, 76.5%, and 0.86 (95% CI: 0.83-0.88) in the development cohort, respectively, and comparable predictive performance in the validation cohort. The score model was demonstrated by a nomogram. CONCLUSIONS:Given the high mortality of candidaemia in ICU patients, the CanDi-Score may serve as a valuable tool for early prediction and timely empirical antifungal treatment. Key predictors include CCI, presence of concurrent infections, the duration of CVC use, and TPN administration. CanDi-Score provides clinicians with a practical approach to identify high-risk patients and guides decision-making for the early initiation of antifungal treatment.
BACKGROUND:Osteoarticular infection is an emerging complication of sporotrichosis, often leading to a significant increase in morbidity and longer treatment. METHODS:We conducted a retrospective cohort study of osteoarticular sporotrichosis (OS) in southeastern Brazil (2014-2024) using clinical, epidemiological, and molecular data. RESULTS:Among 252 patients, 20 (7.9%) had OS, including 10 (4%) with osteomyelitis. The median age of patients with OS was 58 years (IQR 39-64; range 18-83) and 55% were male. Hypertension (45%), diabetes (40%), alcohol use (40%), smoking (40%), and HIV infection (15%) were the most frequent conditions identified. Cutaneous lesions occurred in 95% of cases, and 90% of patients presented with arthralgia and edema. Multifocal OS was observed in 50% of cases, most commonly affecting the knees, fingers, and wrists. The mean time to diagnosis was 14.2 months. Most patients were treated with itraconazole combined with amphotericin B; 13 required surgical intervention, including 2 amputations. The mean treatment duration was 21 months. Multisystem involvement due to sporotrichosis was observed in 45% of cases, including pulmonary involvement. Mortality was 15%. Diabetes (OR = 4.11; 95% CI, 1.50-11.38; p = 0.006) was independently associated with OS. CONCLUSIONS:OS is associated with substantial morbidity and prolonged treatment. Diabetes may increase the risk of OS, while delayed diagnosis jeopardizes outcomes, underscoring the need for early management.
BACKGROUND:The efficacy and safety of rezafungin in invasive candidiasis (IC) and candidaemia was demonstrated in the Phase 2 STRIVE and Phase 3 ReSTORE trials, and an additional cohort of patients in ReSTORE from China (ReSTORE China). OBJECTIVES:This post hoc analysis is the first time that combined data from all double-blind, randomised Phase 2 and 3 rezafungin trials have been evaluated. Outcomes were comprehensively assessed across a large, diverse population. METHODS:Data were assessed from adults with candidaemia/IC in STRIVE (NCT02734862) and ReSTORE (NCT03667690) (including the China extension cohort) who received weekly rezafungin 400/200 mg or daily caspofungin 70/50 mg for ≤ 4 weeks. Efficacy was assessed in the modified intent-to-treat population. Endpoints were Day 30 all-cause mortality (ACM, primary), mycological response at Days 5 and 14 (secondary) and time to negative blood cultures (TTNBC, secondary). Treatment-emergent adverse events were assessed in the safety population. RESULTS:Overall, 372 patients were included (rezafungin 179; caspofungin 193). Day-30 ACM was 20% (33/161) for rezafungin versus 22% (39/178) for caspofungin (weighted difference, -2.4% [95% confidence interval -11.2 to 6.4]). Day-5 and Day-14 mycological eradication rates were 73% and 70% for rezafungin versus 65% and 68% for caspofungin, respectively. Median TTNBC was shorter for rezafungin than for caspofungin (23.1 versus 36.7 h, respectively; p = 0.0073). Adverse-event profiles were generally similar across treatments. CONCLUSIONS:This pooled analysis of Phase 2 and Phase 3 data, including the China extension cohort, supports the efficacy and safety of rezafungin. Rezafungin was non-inferior to caspofungin, with earlier mycological eradication.
At the beginning of Friedrich Staib's academic career in the 1950s, medical mycology was a young discipline in Germany. He studied veterinary and human medicine, earning two doctorates. Initially fascinated by the changes in intestinal flora caused by the newly emerging broad-spectrum antibacterials, i.e., the selection of fungi. In 1953, he began setting up a mycological laboratory at the University of Würzburg and qualified as a professor in microbiology in 1962. In 1968, he became the head of the mycology department, which he established, at the Robert Koch Institute, Germany's public health Institute in Berlin. His work focused on improving the identification of fungi, both within hosts and the environment. His research on Cryptococcus neoformans (Staib agar indicator medium based on the virulence factor melanin for cultivation) gained him international recognition. He was the first to describe secreted proteases from Candida albicans as a virulence mechanism of the main human fungal pathogen. Later, nosocomial exposure of immunocompromised individuals to Aspergillus fumigatus became an issue for him. He cultivated intensive collaboration with clinicians and pathologists, which had a major influence on his research. Staib's broad interest in fungal diagnostics, virulence factors, and environmental niches of fungal pathogens was groundbreaking for medical mycology in Germany and beyond at a time when systemic mycoses were becoming increasingly important. With his systems thinking, he influenced doctoral students and was a role model for public health.
Signal transducer and activator of transcription 3 (STAT3) is a key transcription factor that regulates a spectrum of genes and signalling pathways critical for the antifungal immune response. Mutations in the STAT3 gene confer susceptibility to severe and recurrent fungal infections, predominantly via disruption of interleukin-17 (IL-17)-mediated immunity. This review synthesises current mechanistic insights into STAT3 dysfunction, which impairs the differentiation and effector function of T helper 17 (Th17) cells. This defect results in a profound deficiency of IL-17 and IL-22, which are indispensable for orchestrating antifungal defence at mucosal barriers. The subsequent immunopathological features include impaired neutrophil recruitment to fungal invasion sites, compromised epithelial barrier function and failure to eradicate pathogens such as Candida spp. and Aspergillus spp. Consequently, individuals harbouring STAT3 mutations face a substantially increased risk of disseminated and chronic fungal diseases. Elucidating this STAT3-dependent signalling pathway is essential for deciphering the pathological basis of fungal susceptibility across diverse clinical settings and informing the development of targeted immunotherapies, including immunomodulatory and genetic therapeutic strategies. Additionally, we performed a systematic review of 135 published cases linking STAT3 mutations to fungal infections, aiming to further characterise the role of STAT3 gene defects in fungal susceptibility.
BACKGROUND:Immunocompromised children with hematologic malignancies or undergoing allogeneic haematopoietic stem cell transplantation (HSCT) are at high risk for invasive fungal diseases (IFDs). Reported incidence varies considerably due to heterogeneous diagnostic criteria, antifungal strategies and environmental conditions. Environmental preventive measures, although highly relevant, remain underrecognised determinants of IFD incidence. METHODS:This retrospective, single-centre trial included paediatric cancer or transplant patients at high risk for IFD treated before (Cohort 1) and after (Cohort 2) relocation of a paediatric cancer centre from a 1990s building to a state-of-the-art facility with improved environmental protection standards (observation periods: 56 and 12 months, respectively). Antifungal prophylaxis continuously followed local standards. IFD was diagnosed according to 2019 EORTC/MSGERC criteria. Primary endpoint was IFD incidence; secondary endpoints included prophylaxis use, IFD management and mortality. RESULTS:This study included 186 patients (Cohort 1: n = 140; Cohort 2: n = 46). Baseline characteristics were comparable between both cohorts. Adherence to prophylaxis standards exceeded 98%, with liposomal amphotericin B being the most common agent. In Cohort 1, 25 possible, probable, or proven IFD occurred, mainly pulmonary aspergillosis, whereas no cases were observed following implementation of environmental measures in Cohort 2 (17.9% vs. 0%, p = 0.002). Most IFD cases occurred in HSCT recipients. IFD was associated with increased mortality (p < 0.0001). CONCLUSIONS:In this contemporary paediatric cancer and transplant setting, environmental protective measures were associated with a marked reduction in IFD incidence, complementing consistent pharmacologic prophylaxis. These findings underscore environmental protection as essential for IFD prevention in high-risk paediatric populations.
Glycoprotein 130 (GP130) is an archetypal class I cytokine receptor that serves as a shared signalling subunit for a group of cytokines known as interleukin 6 (IL-6)-type cytokines. GP130 does not have an intrinsic kinase activity and relies on Janus kinases (JAK) 1, 2, or Tyrosine kinase 2 (TYK2) for phosphorylation of tyrosine residues on its cytoplasmic domain for signal transduction. In this study we investigated the molecular mechanism of GP130 activation. We utilized GP130 constructs that were held in varying states of activation by replacing the entire extracellular region of the receptor with a leucine zipper dimerisation domain and inserted alanine residues into the extracellular juxtamembrane linker sequence to induce rotation of the transmembrane domains. These chimeras differentially activated the associated JAK2 molecules which also correlated with receptor tyrosine phosphorylation status. Förster resonance energy transfer (FRET) microscopy in live cells was used to show that GP130 cytoplasmic domains were in close proximity in active chimeras compared to the inactive receptors, presumably to facilitate JAK protein activation. Coarse-grained molecular dynamics simulations provided a structural rationale for this register-dependent mechanism, showing that active chimeras preferentially maintain compact transmembrane packing and reduced membrane-proximal cytosolic spacing, whereas signalling-deficient constructs sample more heterogeneous transmembrane geometries and increased cytosolic separation. Finally, mutational analysis identified the negatively charged juxtamembrane residues E617 and E619 as critical for signal transduction; charge reversal at these positions in the full-length receptor generated a dominant-negative GP130 variant devoid of signalling capacity.
BACKGROUND:Invasive pulmonary fungal infections (IPFIs) in immunocompromised children carry high morbidity and may interrupt life-saving chemotherapy or haematopoietic stem cell transplantation (HSCT). Evidence on perioperative risk stratification for surgical management is limited. PATIENTS AND METHODS:We conducted a single-center retrospective cohort study of patients < 16 years with proven/probable IPFI who underwent lung resection from 2017 to 2025, with fungal infection confirmed by pathology. Preoperative clinical variables, laboratory tests and CT features were collected. Outcomes included intraoperative blood transfusion, severe postoperative complications, 90-day mortality and time to resumption of chemotherapy/HSCT. An exploratory preoperative weighted risk score was derived and evaluated. RESULTS:Thirty-three patients were included (median age 9 years; 75.8% male). Aspergillus was the most common pathogen (72.7%); 57.6% had centrally located lesions and 12.1% had multilobe involvement. Procedures were mainly lobectomy (66.7%) or wedge resection (30.3%), with VATS in 45.5%. Peripheral lesion location was associated with less intraoperative transfusion, while hemoptysis and central lesion predicted delayed resumption of chemotherapy/HSCT; preoperative platelet count < 100 × 109/L, multilobe involvement and central location were significantly associated with severe complications. Integrating these independent findings, a 0-8 point composite risk score was constructed (optimism-adjusted C-index: 0.948). The model effectively stratified outcomes: severe complications occurred in 0% (low), 26.7% (moderate) and 75% (high) (p = 0.004). Among survivors, median time to resume chemotherapy/HSCT was 18 days (low) versus 35 days (moderate) versus 78 days (high) (p < 0.001). All 90-day deaths occurred in the high-risk group (p < 0.001). CONCLUSIONS:Surgery can support source control and timely oncologic treatment in selected paediatric IPFI. A simple, statistically validated preoperative score may help anticipate surgical risk and recovery time and identify a high-risk subgroup with poor short-term outcomes.
Checkpoint inhibitors have transformed cancer treatment, yet predicting responses remains challenging. Mitochondrial quality decreases in tumor infiltrating lymphocytes and correlates with impaired antitumor immunity in animal models. Mitochondrial membrane potential (MMP) increases with T cell activation and may also indicate cellular dysfunction. Here, we assessed the MMP of tumor-associated T cells as an indicator of cell phenotypes and immunotherapy responses in non-small cell lung carcinoma and clear cell renal cell carcinoma patients. Primary tumors were collected followed by analysis of peripheral blood mononuclear cells prior to and after 3 wk on treatment with immune checkpoint inhibitors (ICIs). Peripheral blood mononuclear T cells were analyzed for MMP using tetramethylrhodamine ethyl ester (TMRE) and sorted into high and low populations. TCRβ and single-cell RNA sequencing of primary tumors identified and characterized peripheral blood T cell clones associated with the tumor microenvironment. As anticipated, ICI therapy increased the frequency of effector T cells in patients who experienced clinical benefit. TMREhigh peripheral blood T cells with tumor-matching TCRβ sequences had elevated oxidative phosphorylation gene signatures. Gene signatures of stress and exhaustion, such as Tigit and Cmc1, were also elevated in the TMREhigh CD8 T cell populations, while gene expression patterns in TMRElow cells suggested mitochondrial fitness and cell longevity. Importantly, clinical benefit from ICIs was negatively correlated with the TMREhigh CD8 T cell gene expression signature. These findings highlight a T cell population characterized by elevated MMP that correlates with exhaustion-like transcriptional states and poor response to immunotherapy.
Despite an effective vaccine against the hepatitis B virus (HBV), there are about 250 million people living with chronic HBV (CHB) worldwide and one million deaths annually. Most children and about 5% of adults exposed to HBV will fail to clear the virus, developing a lifelong infection. Hepatitis B surface antigen (HBsAg)-specific antibody (HBsAb) is protective in uninfected individuals and is considered a component of a functional cure. Immune factors that play important roles in regulating inflammation, such as TGF-β, IL-10, and regulatory T cells (Tregs), may also contribute to CHB pathogenesis. However, the early regulatory factors that promote HBsAg seroconversion are not well understood. To address this, we utilized adeno-associated virus (AAV)-mediated delivery of HBV (AAV-HBV) to mice. In this model, C57BL/6 mice fail to develop effective HBsAb responses, while BALB/c mice more efficiently seroconvert HBsAg. While inhibiting TGF-β, IL-10, or Tregs did not impact serum HBsAg levels in C57BL/6 mice, TGF-β depletion in BALB/c mice ablated the humoral response to HBsAg. Neutralizing IL-10, blocking CTLA-4, or depleting Tregs alone did not affect the HBsAb response in BALB/c mice. However, Treg depletion in the absence of TGF-β restored HBsAg clearance in an IL-10- and CTLA-4-independent manner. These findings highlight the immune balance regulated by TGF-β in the early adaptive response to an HBV antigen, as well as context-dependent compensatory interactions that may directly or indirectly impact antigen-specific humoral immunity.
In inflammatory tissue niches, macrophages encounter intense oxidative stress due to their own production of reactive oxygen and nitrogen species as part of antimicrobial defense. Our findings reveal that inflammatory macrophages deploy distinct, context-dependent redox-protective mechanisms to survive this self-inflicted stress, thereby avoiding ferroptotic cell death. Specifically, LPS-activated macrophages, M(LPS), rely on the GTP cyclohydrolase 1 (GCH1)-tetrahydrobiopterin (BH4) pathway for ferroptosis resistance, whereas LPS + IFN-γ-activated macrophages, M(LPS-IFN-γ), depend primarily on nitric oxide produced by inducible nitric oxide synthase (iNOS)-with the BH4 pathway suppressing cell death in the absence of nitric oxide. These distinct adaptations highlight a novel GCH1-BH4-iNOS axis that governs macrophage ferroptosis susceptibility. In both the LPS or the LPS + IFN-γ-activated settings, the redox-protective phenotype is reversible: Removal of inflammatory stimuli abolishes the protection, indicating that this metabolic programming requires continuous stimulation and is not a permanently fixed state. These findings uncover redox metabolism-guided metabolic distinctions between inflammatory macrophages and reveal how they preserve viability over prolonged inflammatory activation. Ultimately, our findings establish the GCH1-BH4-iNOS axis as a central, targetable mechanism to manipulate macrophage ferroptosis resistance for therapeutic purposes.
Chemokine CCL20, secreted by gut epithelial cells, demonstrates markedly increased expression during episodes of chronic inflammation and infection. Mucosal barriers recruit more CCR6+ B cells and have higher immunogloblin A (IgA) Ab levels during normal, infectious, and inflammatory states. Ig isotypes at the mucosal surface are pivotal in modulating inflammatory responses and controlling infections. However, the intrinsic signaling pathway mediated by CCR6-CCL20 in B cells-in particular, its impact on Ig isotype expression-remains insufficiently investigated. In this study, the dextran sodium sulfate (DSS)-induced gut inflammation model in C57BL/6 mice was used. Our findings indicate that DSS administration elevates CCL20 production in the gut epithelium, which, in turn, enhances the differentiation of IgA+ B cells in gut-associated lymphoid tissues, while concurrently reducing both IgG1+ B-cell populations and serum IgG1 levels, in a CCR6-dependent manner. Furthermore, stimulation with CCL20 through CCR6 induces phosphorylation of the AKT/mTOR/STAT3 signaling pathways in B cells. Pharmacological inhibition of mTOR signaling with rapamycin effectively abrogated CCL20-driven differentiation of IgA+ B cells. Collectively, these results suggest a significant role for CCR6-CCL20 signaling, alongside other costimulatory mechanisms, in regulating Ig isotype switching at the mucosal barrier during intestinal inflammation, thereby offering important insights into CCR6-mediated inflammatory pathologies.
Neuroblastoma (NB) is the most common extracranial solid tumor in children and remains a major therapeutic challenge in high-risk patients because of frequent recurrence and metastasis. γδT cells are a unique lymphocyte subset with potent antitumor activity and are widely distributed in NB tumors. However, the immunosuppressive tumor microenvironment limits γδT-cell effector function and promotes immune evasion. In this study, we found that ULBP1 expression was frequently down-regulated in NB tumor tissues and cell lines and that low ULBP1 expression was associated with high-risk clinical features and poor prognosis. Further investigation revealed that doxorubicin, a key chemotherapeutic agent used in NB treatment, up-regulated ULBP1 through down-regulating DNA methyltransferase 1 (DNMT1), thereby decreasing methylation of the ULBP1 promoter. This epigenetic modulation sensitized NB tumor cells to γδT-cell-mediated cytotoxicity in vitro and in vivo. Collectively, our findings uncover a novel mechanism by which doxorubicin enhances NB tumor susceptibility to γδT-cell-mediated killing through ULBP1 up-regulation. This study provides a strong rationale for combining chemotherapy with γδT-cell-based immunotherapy to improve outcomes in high-risk NB patients.
BACKGROUND:Chronic and recalcitrant dermatophytosis has become increasingly problematic in dermatology practice, largely due to emerging antifungal resistance, affecting not only terbinafine but also azoles. Among the causative agents, Trichophyton indotineae has emerged as a key pathogen associated with treatment failure, extensive disease, and frequent relapse, even in immunocompetent patients. OBJECTIVE:This study aimed to evaluate and compare two rapid molecular diagnostic approaches: A commercial multiplex qPCR assay (DermaGenius Resistance Multiplex PCR, DermaGenius RMP) and a T. indotineae-specific in-house qPCR assay, focusing on their practical value for early detection of recalcitrant dermatophyte infections and terbinafine resistance in routine dermatology practice. METHODS:Sixty-four dermatophyte isolates obtained from patients with chronic or treatment-resistant dermatophytosis in Türkiye wereanalysed. Species identification and detection of squalene epoxidase (SQLE) gene mutations associated with terbinafine resistance were performed using DermaGenius RMP and the in-house T. indotineae-specific qPCR assay, with confirmatory ITS/SQLE sequencing and CLSI microbroth dilution antifungal susceptibility testing. RESULTS:Overall concordance between the two qPCR methods was 93.8% (κ = 0.74, z = 5.99, p < 0.001) for T. indotineae identification. Most recalcitrant cases were caused by T. indotineae, and SQLE mutations were detected in > 90% of these isolates, consistent with the observed clinical resistance. DermaGenius RMP enabled rapid, standardised detection of terbinafine resistance-associated mutations suitable for routine diagnostics, whereas the in-house qPCR provided highly specific identification of T. indotineae. Notably, 10 T. indotineae isolates harboured the SQLE F397L substitution despite terbinafine susceptibility. CONCLUSIONS:Rapid molecular diagnostics, particularly qPCR-based assays, provide actionable information early in the course of infection. In this study, both assays showed comparable performance for T. indotineae detection. Prompt identification of T. indotineae and associated resistance mutations may help avoid ineffective antifungal therapy, reduce chronicity, and support rational treatment decisions in routine clinical practice.
Interferon-gamma (IFN-γ) is a powerful transactivating signal eliciting hundreds of IFN-stimulated genes (ISGs) in humans to help combat infection. Most ISGs remain uncharacterized, and here we searched for actin-binding candidates that could potentially target intracellular pathogens to block their spread or promote immune cell migration into infected tissues. Dual RNA-Seq and in silico mining across 1,933 data sets discovered >225 actin-related genes; the most highly expressed was XIRP1 (xin actin binding repeat containing 1 protein), a new ISG with no reported immune function. We found XIRP1 induction required IFN-γ plus IL-1β or exposure to pathogenic Listeria, Shigella, or Salmonella in immune and non-immune cells. Within IFN-γ-activated human macrophages, the XIRP1 protein localized to actin-rich podosomes where it formed a dome-shaped cap facing the cytosol; genetic XIRP1 ablation led to significant actin loss from these structures. Within infected cells, XIRP1 was recruited onto cytosolic Listeria monocytogenes in an ActA-dependent manner. Live imaging found many listeriae were fully encapsulated by XIRP1 whereas incomplete XIRP1 coating allowed pathogen escape from the initial coat structure. Together, our results identify XIRP1 as a new podosome-associated ISG that targets cytosolic bacteria as part of the IFN-γ-induced defense program in humans.
Gamma delta (γδ) T cells emerge early during human gestation and are uniquely equipped to protect the fetus and infant following infection, due to their innate-like recognition of conserved molecular ligands. Following congenital cytomegalovirus infection (cCMV), Vδ1 T cells have been shown to expand, differentiate, and upregulate cytotoxic mediators, but display markedly restricted γδTCR diversity compared to CMV-infected adults. Early fetal γδ T cells are biased toward rapid effector function and comprise a distinct ontological "layer" that can be distinguished from late gestation γδ T cells based on TCR characteristics. To better understand the contribution of fetal γδ T cells to antiviral defense in utero, we analyzed γδ T cells from cCMV+ and uninfected neonates in Uganda using flow cytometry and paired single-cell RNA and TCR sequencing. We observed that in cCMV+ neonates, γδ T cells clonally proliferate and differentiate into a uniform population of cytotoxic effectors. The expanded Vδ1 population is comprised of diverse clonotypes with broad Vγ chain usage, with a striking correlation between expansion and publicity. Overall, γδTCR repertoires of cCMV+ infants have shorter CDR3 lengths and fewer N additions, suggesting they derive from early fetal progenitor cells. In cCMV+ infants, most cells with fetal γδTCR characteristics are effector-differentiated, whereas in uninfected infants, such cells are rare and predominantly naïve. Together, these findings demonstrate that cCMV infection drives an oligoclonal expansion of highly cytotoxic effector γδ T cells with fetal-like TCR features, illustrating how the developing immune system prioritizes broad reactivity and rapid effector function over specificity.
Salmonella enterica is a gastrointestinal pathogen that causes a variety of intestinal and systemic clinical disease. Vaccine development for systemic salmonellosis requires a deeper understanding of protective mechanisms and the relative contribution of mucosal and systemic host responses to bacterial elimination. Here, we examined the relative importance of mucosal and systemic immunity in the control of systemic salmonellosis. Delivery of a live-attenuated vaccine strain via a parenteral route did not elicit a substantial mucosal immune response, but was still sufficient to protect mice from systemic Salmonella infection. A prominent feature of the protective systemic response was the establishment of Salmonella-specific tissue resident memory (TRM) CD4 T cells in the liver. Although adoptive transfer of hepatic TRMs was sufficient to protect mice from challenge infection, TRMs from the intestinal lamina propria reduced bacterial loads but failed to fully protect mice from infection. The protective contribution of liver and LP TRMs was partially dependent on the expression of IL-18R and the corresponding ability to elicit noncognate CD4 T cell responses in vivo. Overall, these data suggest that a parenteral vaccination approach that efficiently induces liver TRMs expressing IL-18R should provide robust protection against mucosal or systemic infection with Salmonella.
