Search Results (188)

Sporothrix schenckii is a thermodimorphic fungus and one of the main etiological agents of sporotrichosis, a globally distributed subcutaneous mycosis that primarily affects the skin, subcutaneous tissue, and lymphatic system. Historically regarded as the classical species within the Sporothrix pathogenic clade, S. schenckii remains a clinically relevant pathogen and an important biological model for studying fungal dimorphism, virulence, and host–pathogen interactions. Major virulence factors include melanin production, thermotolerance, hydrolytic enzymes, and adhesins, all of which contribute to its survival and dissemination within the host. Clinically, S. schenckii causes a broad spectrum of manifestations ranging from fixed and lymphocutaneous cutaneous forms to disseminated and extracutaneous infections, particularly in immunocompromised individuals. This species exhibits a cosmopolitan distribution with endemic foci in the Americas, Asia, and Africa, and can be transmitted through both sapronotic and zoonotic routes. Diagnosis relies on fungal isolation, molecular identification, and histopathological examination, whereas treatment mainly involves itraconazole, potassium iodide, and amphotericin B for severe cases. This review integrates current knowledge on the biology, virulence, immune response, epidemiology, and treatment of S. schenckii, providing an updated overview of its significance as a medically important fungal pathogen with global relevance. Full article

Hyaluronic acid (HA) is a ubiquitous glycosaminoglycan essential for maintaining tissue hydration, structural integrity, and immunological homeostasis in vertebrates. Although traditionally regarded as a host-derived molecule, HA is also produced by a range of microorganisms, most notably Streptococcus spp., through specialized hyaluronan synthases (HAS). Microbial HA and host-derived HA fragments play key roles not only in tissue physiology but also in infection biology, influencing microbial virulence, biofilm formation, and immune evasion. In bacteria, HA-rich capsules promote adhesion, shield pathogens from complement-mediated opsonization and phagocytosis, and facilitate dissemination through host tissues. Conversely, HA-degrading enzymes and reactive oxygen species generate low-molecular-weight HA fragments that amplify inflammation by activating—toll-like receptor 2 (TLR2)/toll-like receptor 4 (TLR4) signaling, contributing to chronic inflammatory states. Furthermore, microbial HA modulates biofilm organization in both bacterial and fungal pathogens, enhancing persistence and antimicrobial tolerance. Clinically, widespread use of HA-based dermal fillers has generated increasing concern over delayed biofilm-associated infections, diagnostic challenges, and complications arising from microbial contamination and host–microbe interactions. Recent advances in HA engineering, including anti-microbial HA conjugates and receptor-targeted biomaterials, offer promising strategies to mitigate infection risk while expanding therapeutic applications. This review synthesizes current knowledge on HA biosynthesis across biological kingdoms, its dualistic role in health and disease, and its emerging relevance at the interface of microbiology, immunology, and biomedical applications. Full article

Fungal mycelial pellets (MPs) exhibit high biomass-loading capacity; however, their application in wastewater treatment is constrained by structural fragility and the risk of environmental dispersion. To overcome these limitations, a dual-crosslinked polyvinyl alcohol–alginate gel (10% PVA, 2% sodium alginate) embedding strategy was developed and stabilized using 2% CaCl₂ and saturated boric acid. This encapsulation enhanced the tensile strength of MPs by 499% (310.4 vs. 62.1 kPa) and improved their settling velocity by 2.3-fold (1.12 vs. 0.49 cm/s), which was critical for stability under turbulent bioreactor conditions. Following encapsulation, the specific oxygen uptake rates (SOURs) of three fungal strains (F557, Y3, and F507) decreased by 30.3%, 54.8%, and 48.3%, respectively, while maintaining metabolic functionality. SEM revealed tight adhesion between the gel layer and both surface and internal hyphae, with the preservation of porous channels conducive to microbial colonization. In sequential-batch reactors treating sulfamethoxazole (SMX)-contaminated wastewater, gel-encapsulated MPs combined with acclimated sludge consistently achieved 72–75% SMX removal efficiency over six cycles, outperforming uncoated MPs (efficiency decreased from 81.2% to 58.7%) and pure gel–sludge composites (34–39%). The gel coating inhibited hyphal dispersion by over 90% and resisted mechanical disintegration under 24 h agitation. This approach offers a scalable and environmentally sustainable means of enhancing MPs’ operational stability in continuous-flow systems while mitigating fungal dissemination risks. Full article

Fig (Ficus carica) orchards in the Salento peninsula (southeastern Apulia region, Italy) are increasingly affected by decline syndromes whose etiology remains poorly resolved. In this paper, we provide a first characterization of a complex disease outbreak, integrating field surveys, fungal isolation, molecular phylogenetics, and pathogenicity assays. Symptomatic trees displayed chlorosis, defoliation, cankers, vascular discoloration, and wilting, frequently associated with bark beetle galleries. Mycological analyses revealed a diverse assemblage of fungi, dominated by Botryosphaeriaceae (including Neofusicoccum algeriense, and Lasiodiplodia theobromae), the Fusarium solani species complex (notably Neocosmospora perseae), and Ceratocystis ficicola. While C. ficicola was isolated with lower frequency, its recovery from adult beetles—including Cryphalus dilutus—supports a role in insect-mediated dissemination in addition to soilborne infection. Pathogenicity tests demonstrated that N. algeriense and N. perseae, together with C. ficicola, caused severe vascular lesions and wilting, confirming their contribution to fig decline. By contrast, other Fusarioid strains showed no pathogenicity, consistent with their role as latent or stress-associated pathogens. This study provides the first evidence that N. algeriense and N. perseae act as pathogenic agents on fig, highlights their interaction with C. ficicola within a multifactorial decline syndrome, and identifies dual epidemiological pathways involving both soil/root infection and insect-facilitated dissemination via beetles such as C. dilutus. These findings redefine fig decline in the Salento peninsula (southern Italy) as a multifactorial disease rather than a single-pathogen outbreak, with significant implications for diagnosis, epidemiology, and integrated management strategies. Full article

Soybean rust, caused by Phakopsora pachyrhizi, is a major foliar disease that often escapes fungicide control, necessitating alternative strategies. We investigated whether phyllosphere arthropods, such as mites and thrips, facilitate the secondary dispersal of the mycoparasitic fungus Simplicillium under controlled conditions. Detached soybean leaves inoculated with P. pachyrhizi were subjected to either arthropod-exposed or arthropod-excluded treatments. Simplicillium isolates were significantly more abundant in the presence of arthropods. Molecular identification revealed identical ITS genotypes of S. lamellicola from both infected pustules and thrips, indicating vector-mediated fungal transmission. While some Simplicillium strains persisted epiphytically without vectors, their spread was minimal. These results highlight a promising approach to enhance the effectiveness of Simplicillium-based biocontrol through natural arthropod-mediated dissemination, warranting field validation of this self-disseminating strategy. Full article

Coccidioides species are thermally dimorphic fungal pathogens that cause coccidioidomycosis (Valley Fever) primarily in North and South America. Coccidioides grow as hyphae that differentiate into arthroconidia, which can be aerosolized upon soil disturbance, and inhaled by the mammalian host to cause pulmonary infections with occasional dissemination to other organs. In the context of mouse models, current methods of infection include intranasal, intravenous, and intraperitoneal delivery of the arthroconidia into mice. To explore an aerosol route of infection, we compared the intranasal method with aerosolization using the Glass-Col Inhalation Exposure System (IES). Infection with a dose of 2 × 10⁶ CFU/mL, nebulized in 5 mL of PBS, but not in water, was able to infect mice, albeit inconsistently, compared to intranasal challenge. Arthroconidia were detected inside the IES after the nebulization and decontamination cycles. These studies highlight some of the challenges with aerosolization of Coccidioides arthroconidia and serve as a reminder about biosafety considerations for use of the IES to aerosolize pathogens. Full article

Mycosis is caused by, among other factors, filamentous fungi, ubiquitous molds belonging to Aspergillus spp. which are often opportunistic pathogens. Over 100 species of Aspergillus have been described. The most common species responsible for diseases in humans and animals are Aspergillus fumigatus and Aspergillus niger, with Aspergillus flavus and Aspergillus clavatus being somewhat rarer. Aspergillus causes a range of diseases, from localized colonization and hypersensitivity reactions, through chronic necrotizing infections, to rapidly progressing angioinvasion and dissemination, leading to death. Testicular mycosis is extremely rarely described in both humans and animals. No studies in the literature report a simultaneous occurrence of testicular tumors and fungal infection of the organ, so the aim of this paper was to describe, for the first time, a case of two independent testicular tumors coexisting with testicular mycosis. A histopathological examination was performed on the left testicle of a male dog, specifically a mixed-breed dog resembling a husky weighing 22 kg and with an age of 8 years. Bilateral orchidectomy was performed for medical reasons due to the altered outline of the left testicle, leading to scrotal deformation. The dog did not show any clinical signs of illness, and the testicles were not painful. The right testicle, according to the operating veterinarian, showed no macroscopic changes, so histopathological verification was not performed. Microscopic imaging of the changes clearly indicated the coexistence of a tumor process involving Leydig cells (Leydigoma, interstitial cell tumor, ICT), Sertoli cells (Sertolioma), and fungal infection of the testis. The case suggests the possibility of the coexistence of tumor processes, which may have impaired local immune response of the tissue, with an infectious, in this case fungal, inflammatory process. Based on the literature, this paper is the first report on the occurrence of two independent histotype testicular tumors and their associated mycosis. Full article

Introduction: Acute Myeloid Leukemia (AML) is a hematologic malignancy characterized by the clonal expansion of myeloid progenitors. While it primarily affects the bone marrow, extramedullary relapse occurs in 3–5% of cases, and it is linked to poor prognosis. Central nervous system (CNS) involvement presents diagnostic challenges due to nonspecific symptoms. CNS manifestations include leptomeningeal dissemination, nerve infiltration, parenchymal lesions, and myeloid sarcoma, occurring at any disease stage and frequently asymptomatic. Methods: A 62-year-old man with a recent history of AML in remission presented with diplopia and aching paresthesias in the left periorbital region spreading to the left frontal area. The diagnostic workup included neurological and hematological evaluation, lumbar puncture, brain CT, brain magnetic resonance imaging (MRI) with contrast, and dermatological evaluation with skin biopsy due to the appearance of nodular skin lesions on the abdomen and thorax. Results: Neurological evaluation showed hypoesthesia in the left mandibular region, consistent with left trigeminal nerve involvement, extending to the periorbital and frontal areas, and impaired adduction of the left eye with divergent strabismus in the primary position due to left oculomotor nerve palsy. Brain MRI showed an equivocal thickening of the left oculomotor nerve without enhancement. Cerebrospinal fluid (CSF) analysis initially showed elevated protein (47 mg/dL) with negative cytology; a repeat lumbar puncture one week later detected leukemic cells. Skin biopsy revealed cutaneous AML localization. A diagnosis of AML relapse with CNS and cutaneous localization was made. Salvage therapy with FLAG-IDA-VEN (fludarabine, cytarabine, idarubicin, venetoclax) and intrathecal methotrexate, cytarabine, and dexamethasone was started. Subsequent lumbar punctures were negative for leukemic cells. Due to high-risk status and extramedullary disease, the patient underwent allogeneic hematopoietic stem cell transplantation. Post-transplant aplasia was complicated by septic shock; the patient succumbed to an invasive fungal infection. Conclusions: This case illustrates the diagnostic complexity and poor prognosis of extramedullary AML relapse involving the CNS. Early recognition of neurological signs, including cranial nerve dysfunction, is crucial for timely diagnosis and management. Although initial investigations were negative, further analyses—including repeated CSF examinations and skin biopsy—led to the identification of leukemic involvement. Although neuroleukemiosis cannot be confirmed without nerve biopsy, the combination of clinical presentation, neuroimaging, and CSF data strongly supports the diagnosis of extramedullary relapse of AML. Multidisciplinary evaluation remains essential for detecting extramedullary relapse. Despite treatment achieving CSF clearance, the prognosis remains unfavorable, underscoring the need for vigilant clinical suspicion in hematologic patients presenting with neurological symptoms. Full article

With the rise in immunocompromised individuals and patients with immune-related comorbidities such as COVID-19, the rate of fungal infections is growing. This increase, along with the current plateau in antifungal drug development, has made understanding the pathogenesis and dissemination of these organisms more pertinent than ever. The mouse model of fungal infection, while informative on a basic scientific level, has severe limitations in terms of translation to the human disease. Here we present data supporting the implementation of the human cerebral organoid model, which is generated from human embryonic stem cells and accurately recapitulates relevant brain cell types and structures, to study fungal infection and dissemination to the central nervous system (CNS). This approach provides direct insight into the relevant pathogenesis of specific fungal organisms in human tissues where in vivo models are impossible. With this model system we assessed the specific brain tropisms and cellular effects of fungal pathogens known to cross the blood–brain barrier (BBB), such as Cryptococcus neoformans. We determined the effects of this fungal pathogen on the overall gross morphology, cellular architecture, and cytokine release from these model organoids. Furthermore, we demonstrated that C. neoformans penetrates and invades the organoid tissue and remains present throughout the course of infection. These results demonstrate the utility of this new model to the field and highlight the potential for this system to elucidate fungal pathogenesis to develop new therapeutic strategies to prevent and treat the disseminated stages of fungal diseases such as cryptococcal meningitis. Full article

The number of fungal infections is steadily increasing, with considerable morbidity and mortality. Additionally, antifungal resistance is a growing concern, highlighting the need to develop new treatment options. One alternative is the use of antimicrobial peptides (AMPs). The aim of this study was to assess the in vitro and in vivo antifungal activity of designed short AMPs, Act-6 and Act 8-20, derived from cecropin transcripts of beetles from the family Scarabaeidae, against eight reference strains of the pathogenic yeasts Candida and Cryptococcus. We also evaluated the effect of these modified AMPs on the biofilm, morphogenesis, and cell morphology of Candida albicans, as well as the in vivo activity via a murine model of disseminated candidiasis. The AMPs herein analyzed exhibit differential antifungal activity against the yeasts assessed, and inhibit biofilm, hyphae, and pseudohyphae formation with morphological alterations in C. albicans. Moreover, the fungal load in mice treated with these AMPs significantly decreased. Altogether, our results suggest that Act-6 and Act 8-20 are promising antifungal molecules to control mycoses. Full article

Fungal biodiversity and ethnomycological knowledge are fundamental components of the biocultural identity of communities within the La Malinche National Park (PNM), a region of ecological and cultural significance in Mexico. This study documented the diversity of wild fungi and their uses in San Miguel Canoa, Puebla, through field excursions with local mushroom gatherers, interviews, and qualitative analysis. Key species such as Russula delica, Boletus aff. edulis, and Amanita basii were identified, playing a vital role in local gastronomy with traditional recipes like mole and pipián. Intergenerational knowledge transmission, crucial for identifying edible fungi and avoiding intoxications, highlights the importance of oral tradition. However, deforestation, illegal logging, and land-use change threaten fungal diversity, a problem exacerbated by the lack of effective conservation policies. The discussion highlights the interplay between biodiversity and culture, emphasizing the significance of the Wild Mushroom Fair organized by the Yolaltepetl collective as an effort to disseminate ethnomycological knowledge and promote the conservation of the PNM. Such community-driven initiatives represent a sustainable model that integrates environmental protection with cultural strengthening. The study concludes that protecting the PNM requires a holistic approach, merging ecological conservation with the recognition of biocultural knowledge. This is essential to preserve both biodiversity and cultural heritage, ensuring their sustainability for future generations. Full article

Cryptococcosis, an opportunistic fungal infection predominantly caused by Cryptococcus neoformans, is the third most common invasive fungal disease in solid organ transplant recipients. While well-characterized in adult kidney transplant (KT) patients, pediatric data remain sparse. This article compares clinical presentation, immune response, renal involvement, and management strategies of cryptococcosis between adult and pediatric KT recipients. In adults, the disease typically presents as cryptococcal meningitis or pulmonary infection, often complicated by delayed diagnosis and high mortality. In contrast, children frequently exhibit non-specific respiratory symptoms or disseminated disease, reflecting immune immaturity and increased susceptibility to hematogenous spread. Key immunopathological differences include impaired Th1 type responses, macrophage dysfunction, and variable complement activity across age groups. Management involves similar antifungal regimens such as liposomal amphotericin B, flucytosine, and fluconazole, but requires weight-based dosing and careful toxicity monitoring in pediatric patients. Early diagnosis through serum cryptococcal antigen screening, appropriate adjustment of immunosuppressive therapy, and coordinated multidisciplinary care are essential. The findings underscore the need for pediatric specific research and clinical vigilance, emphasizing tailored antifungal dosing and individualized immune management to improve outcomes in this vulnerable population. Full article

Diagnosis of histoplasmosis is challenging. A rapid, sensitive, and specific method is essential. Serum is a non-invasive and easy sample to obtain in any hospital. The diagnostic accuracy of different techniques that use serum has been evaluated. Forty-one serum samples from patients with proven or probable histoplasmosis were analyzed. Different diagnostic techniques based on the detection of antibodies (ID Fungal Antibody System), antigens (Histoplasma GM EIA and Platelia^TM Aspergillus Ag), and DNA (“in-house” real-time PCR (RT-PCR) were tested and compared. Additionally, the quantification of cytokines and biomarkers related to histoplasmosis was performed. Global results from 27 samples in which all the tests were performed showed that the sensitivity of the Histoplasma GM EIA kit was 87.5% in patients with disseminated infection and HIV as an underlying disease; in immunocompetent (IC) patients, it was 54.5%. The detection of Histoplasma spp. with the ID Fungal Antibody System was positive in 90.9% of IC and in 62.5% of HIV patients. The Platelia-Asp kit had a low performance in both groups of patients (37.5% in HIV and 9% in non-HIV), and, finally, RT-PCR was better in immunosuppressed patients (44% in HIV vs. 27% in non-HIV). The combination of diagnostic techniques increased the detection of Histoplasma infection in inmunosupressed patients. Overall, patient groups infected with H. capsulatum (Hc) showed higher IL-8, IL-6, IL-1β, TNF-α, and IL-18 median values compared to non-Hc-infected controls. The effectiveness of diagnostic techniques on serum samples is highly influenced by the patient’s clinical presentation and underlying condition. Consequently, a thorough assessment of the patient’s clinical presentation and disease phenotype is crucial in selecting the most suitable diagnostic method. Full article

Aspergillus terreus is an opportunistic fungal pathogen and a major cause of aspergillosis. Its clinical significance is heightened by high mortality rates, dissemination, and resistance to amphotericin B, complicating treatment. The present study investigates the distribution of A. terreus in Tyrolean (Austria) soils and explores potential environmental factors influencing its uneven prevalence. Soil samples from the eastern and western parts of Tyrol were analyzed using soil extraction plating, the soil immersion tube method, and A. terreus-specific qPCR. The results revealed a significantly higher prevalence of A. terreus in the eastern region. Soil parameters, including pH, moisture, organic matter, total carbon, and nitrogen, were assessed for potential correlations with fungal distribution. The presence of A. terreus was significantly associated with lower pH, decreased total carbon and nitrogen, and lower soil density. Random sampling across Austria indicated a lower environmental frequency of A. terreus outside of Tyrol. The susceptibility profiles of amphotericin B, posaconazole, isavuconazole, and voriconazole were determined according to EUCAST guidelines, showing that 98.3% of isolates were wild type for amphotericin B, 100% wild type for voriconazole, 100% resistant to posaconazole, and 87.2% resistant to isavuconazole. Full article

Background: Vasculonecrotic reactions in leprosy are typically associated with type 2 reactions. Differentiating between necrotizing erythema nodosum leprosum (nENL) and Lucio’s phenomenon (LP) can be difficult, as overlapping clinical and histopathological features have been reported. Mycobacterium lepromatosis, a recently identified species causing leprosy, has been sporadically linked to LP. While type 1 reactions are more commonly observed in HIV-coinfected individuals, reports of LP or ENL occurring outside the context of immune reconstitution inflammatory syndrome (IRIS) remain rare. Methods: We report a case of a vasculonecrotic leprosy reaction due to M. lepromatosis in an antiretroviral-naive patient with advanced HIV infection. Results: The patient presented with a two-month history of papules and nodules that progressed to painful necrotic ulcers, accompanied by systemic symptoms. Clinically, the presentation was consistent with nENL; however, histopathological analysis supported a diagnosis of LP. The patient rapidly deteriorated, developing septic shock and dying shortly thereafter. To our knowledge, this is the first reported case of a leprosy-associated vasculonecrotic reaction caused by M. lepromatosis in an HIV-infected individual not associated with IRIS. Conclusions: Vasculonecrotic reactions in leprosy are life-threatening emergencies due to their potential for rapid clinical deterioration and sepsis. In individuals with advanced HIV infection, recognition of these reactions may be challenging, as they can mimic other opportunistic infections, including fungal diseases, malignant syphilis, and disseminated mycobacterial infections. Early identification and prompt treatment are critical to improving outcomes. Full article