Medical mycology最新文献

Mucormycosis is predominantly caused by members of the genera Lichtheima, Mucor, and Rhizopus. Here, we report the genome assemblies and comparative analyses of the clinically relevant species Mucor ardhlaengiktus (CBS 210.80), Mucor circinelloides (CBS 195.68), Mucor janssenii (CBS 205.68), and Mucor griseocyanus (CBS 116.08) to enable molecular analyses.

Lodderomyces elongisporus is an emerging, cryptic opportunistic yeast increasingly linked to fungemia, especially in immunocompromised patients and those with indwelling devices. Frequently misidentified as Candida parapsilosis due to phenotypic overlap, it escapes timely diagnosis, delaying effective therapy. Despite accounting for <2% of candidemia cases, true prevalence is likely underestimated. Critically, L. elongisporus exhibits reduced susceptibility to echinocandins, making misidentification clinically dangerous. To develop and validate the LODDY Test-a novel, cost-effective, pH-indicator-based culture medium for rapid, accurate identification of L. elongisporus, particularly in resource-limited settings. The LODDY Test integrates four differential carbohydrates (sucrose, maltose, lactose, and arabinose) with bromocresol purple. We tested 41 L. elongisporus isolates (1 reference, 40 internal transcribed spacer (ITS) region -confirmed environmental strains) and 40 comparator yeasts (C. parapsilosis sensu stricto, C. albicans, C. tropicalis, and Nakaseomyces glabratus) from urban/peri-urban Thai sites. Species identity was confirmed by ITS sequencing. LODDY results were benchmarked against the Analytical Profile Index 20C Auxanographic assimilation test (API 20C AUX), CHROMagar™ chromogenic medium, and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS), and ITS-DNA sequencing. The LODDY Test achieved 100% sensitivity and specificity, distinctly identifying L. elongisporus (no color change) from yellow-producing Candida spp. and purple N. glabratus. Performance matched MALDI-TOF MS and ITS sequencing but required only basic equipment. The LODDY Test is a low-cost, high-accuracy diagnostic tool suitable for decentralized labs. Its clinical validation in bloodstream isolates is the next step toward improving candidemia outcomes in low-resource settings.

Paracoccidioidomycosis ceti (PCMC), also called lobomycosis, is a cutaneous disease affecting cetaceans worldwide. It is caused by Paracoccidioides ceti, an uncultivable fungal species recently classified within the Paracoccidioides genus. Although several molecular markers have been used to investigate the PCMC pathogen, the alpha-tubulin gene (TUB1), commonly utilized in genetic studies of cultivable Paracoccidioides, has remained unexplored in this taxon. In this study, we applied a nested polymerase chain reaction targeting TUB1 to amplify fungal sequences from two new cases of PCMC in Brazil: a Lahille's bottlenose dolphin (Tursiops truncatus gephyreus) and a common bottlenose dolphin (T. truncatus truncatus). Comparative analysis revealed that the sequences obtained from the infected dolphins were identical to each other and shared similarities with fungi belonging to the P. brasiliensis complex. In the haplotype analysis, P. ceti was found to be only a few mutational steps away from P. brasiliensis sensu stricto and P. americana. Notably, the latter shared the same cleavage sites as P. ceti in the in silico restriction fragment length polymorphism analysis. Our findings demonstrate that the nested PCR assay, originally developed for cultivable Paracoccidioides species, is also effective in amplifying TUB1 from P. ceti. Therefore, this method can be considered an additional tool for phylogenetic studies of this uncultivable species, contributing to a better understanding of this peculiar pathogen.

Antifungal stewardship is important for promoting quality care and tackling the emergence of drug resistance. Evaluation of the quantity and appropriateness of common antifungal prescriptions like fluconazole is essential in the development of these programmes. To perform a clinical audit of fluconazole prescribing and explore whether involvement of pharmacy students in this process was feasible and meaningful from both pharmacy student and health system perspectives. An audit was conducted of all fluconazole prescriptions from January 2024 to March 2024 at two Sydney hospitals. Trained pharmacy students, under the supervision of antimicrobial stewardship pharmacists and physicians, completed the audit using the Antifungal National Antimicrobial Prescribing Survey audit tool. Prescriptions were assessed for their compliance to guidelines and appropriateness. Data on pharmacy students' educational experience was collected by a 5-point Likert scale survey. A total of 145 fluconazole prescriptions were audited: 34 for empiric therapy, 56 for directed therapy, and 56 for prophylaxis. A total of 91 (62.8%) prescriptions were assessed as appropriate, 46 (31.7%) were inappropriate, and 8 (5.5%) were not assessable. Potential drug-drug interactions were identified in 17 patients receiving fluconazole doses of 200 mg or greater, of which three were clinically significant, requiring intervention. Students had positive experiences contributing to quality use of medicines, in terms of enjoyment, support, and education. Inappropriate fluconazole use was common. Pharmacy students made a positive contribution to the antifungal audit, promoting good stewardship practises for the hospital while accessing enhanced learning and development opportunities.

Sporothrix schenckii is the most prevalent etiological agent of sporotrichosis in Mexico, a neglected subcutaneous mycosis with hyperendemic foci in mountainous regions. Despite its public health importance, the phenotypic and virulence-related features of clinical isolates circulating in these areas remain poorly characterized. Ten clinical isolates were molecularly identified and assessed for virulence by determining enzymatic activity (proteases, lipases, catalase), biofilm formation, adhesion to extracellular matrix proteins, antifungal susceptibility, and cell wall composition. Host interaction was evaluated through cytokine profiling in human peripheral blood mononuclear cells, and virulence was assessed using the Galleria mellonella invertebrate infection model. All isolates were confirmed as S. schenckii. Compared to a reference strain, a subset of isolates (740, 742, 183, and 1798) displayed reduced adhesion, extracellular enzymatic activity, and catalase production, as well as altered mannose and rhamnose cell wall content. These isolates induced significantly lower TNFα and higher IL-10 levels in PBMCs and were markedly less virulent in G. mellonella, exhibiting lower mortality, cytotoxicity, and immune activation. All isolates were biofilm producers, and some showed reduced susceptibility to itraconazole or fluconazole. This study reveals phenotypic diversity among S. schenckii clinical isolates in a Mexican hyperendemic region and identifies a subgroup with reduced virulence and immune stimulation capacity. These findings enhance our understanding of the host-pathogen dynamics of sporotrichosis and may inform future diagnostic and therapeutic strategies in endemic settings.

The human skin is a crucial defense system, protecting against external stressors. However, the skin also hosts various microorganisms that impact skin health and disease. Therefore, the polymicrobial interaction in the skin is particularly interesting since it can significantly influence alterations in the virulence traits of microbes and the immune responses of the hosts. This study aimed to investigate the influence of Malassezia restricta, a predominant fungal species on human skin, on the virulence of Staphylococcus aureus, a prominent skin bacterium associated with atopic dermatitis. Our findings revealed that M. restricta effectively interferes with the invasion of S. aureus into human keratinocytes, suggesting a potential mechanism for influencing bacterial infection by the fungus. Additionally, we observed that M. restricta exhibits fibronectin binding capabilities, a key mediator in the S. aureus invasion of keratinocytes. Physicochemical analysis indicated the involvement of a heat-unstable component, likely a M. restricta cell surface protein, which necessitates physical contact between the fungus and keratinocytes for fibronectin binding. Collectively, our results suggest the influential role of M. restricta in the pathogenesis of S. aureus and reveal a novel aspect of this fungal species within the human skin microbial community.

Early diagnosis and treatment are essential for improving outcomes of coccidioidal meningitis. While the detection of IgG by serologic testing of the cerebrospinal fluid (CSF) has been a mainstay of diagnosis for years, the diagnosis of coccidioidal meningitis in clinical practice can be very challenging due to suboptimal sensitivity of laboratory tests. We reviewed the results of the CSF diagnostic test results from the initial lumbar puncture in 110 patients with proven, probable, and likely coccidioidal meningitis from 1989 to 2024. One hundred four patients were diagnosed with coccidioidal meningitis on the initial CSF examination. The positivity rate of the first CSF testing was 89.1% (n = 64) for IgG by enzyme immunoassay, 62.2% (n = 98) for IgG by immunodiffusion, and 70.2% (n = 104) for IgG by complement fixation, 4.4% (n = 90) for fungal culture, 18.8% (n = 69) for polymerase chain reaction, and 33% (n = 21) for Coccidioides antigen. The non-specific fungal marker 1,3-β-d-glucan was positive in the CSF in 70.4% (n = 27) of samples. Contrasted brain magnetic resonance imaging identified leptomeningeal enhancement in 53.1%. Optimal detection of coccidioidal meningitis requires a combination of diagnostic modalities.

Scedosporium/Lomentospora species are ubiquitous moulds that can cause deep-seated infections and allergic bronchopulmonary mycoses (ABPM). Serodiagnosis is currently performed by immunoprecipitation (IP) techniques, which are time-consuming and lack reproducibility. In addition, as antigenic extracts for these fungi are not commercially available, many centers stopped performing this analysis. Therefore, there is a need for automated quantitative alternatives, such as Enzyme linked Immunosorbent Assay (ELISA) . The aim of this study was to develop an ELISA for serodiagnosis of Scedosporium/Lomentospora infections. All sera received for Scedosporium/Lomentospora serodiagnosis expertise from April 2022 to February 2024 were tested in parallel using IP and an in-house ELISA with antigenic extracts from both Scedosporium apiospermum and Lomentospora prolificans. Clinical and biological data such as positive culture, total IgE level, and final diagnosis retained were also collected prospectively. The concordance between techniques was calculated, with χ² tests performed to investigate the correlation between ELISA and culture results or final diagnosis. We tested 58 serum samples from 41 different patients. The concordance between IP and ELISA was 64% for S. apiospermum and 62% for L. prolificans. ELISA results obtained with S. apiospermum antigen extract were significantly correlated with culture results (P < .001, χ² test). ELISA was also more effective than IP to diagnose ABPM. The Scedosporium/Lomentospora ELISA gave satisfactory results, particularly for S. apiospermum. Further validation on a larger cohort is required to implement this ELISA for routine practice instead of IP. In addition, studies should be conducted on purified native proteins or in combination with recombinant antigens to improve standardization.

Trichophyton indotineae has emerged as a significant global public health concern due to its role in recalcitrant dermatophytosis and antifungal treatment failure. Precise identification of T. indotineae is essential for timely and effective therapy, and for curbing the spread of antifungal resistance. However, current routine diagnostic methods are limited to reliably distinguish T. indotineae from other closely related dermatophytes. This study aimed to develop and evaluate three simple, cost-effective molecular methods for the accurate differentiation of T. indotineae. In silico analyses were performed to identify specific restriction enzyme cut sites within the internal transcribed spacer (ITS) region and the topoisomerase II gene of T. indotineae. A total of 430 dermatophyte isolates, including 267 previously identified by ITS sequencing and 163 clinical isolates of unknown identity, were subjected to PCR amplification of ITS and topoisomerase II followed by restriction fragment length polymorphism (PCR-RFLP) analysis using EarI (Eam11041) and BsuRI (HaeIII), respectively. Additionally, a previously described T. indotineae-specific PCR assay was evaluated. The enzyme EarI digested the ITS region of T. indotineae, producing a distinct PCR-RFLP pattern; likewise, BsuRI digested the topoisomerase II gene, enabling accurate differentiation of T. indotineae. The isolates previously identified by ITS sequencing were correctly classified by both methods, achieving high sensitivity and specificity. The T. indotineae-specific PCR assay demonstrated high sensitivity, although faint cross-reactivity was observed with T. tonsurans isolates. The ITS-PCR-RFLP and topoisomerase II-PCR-RFLP methods demonstrated high accuracy, affordability, and speed for the reliable identification of T. indotineae, making them suitable for routine use in clinical laboratories, especially in resource-limited settings. Although the T. indotineae-specific PCR assay showed high sensitivity, occasional cross-reactivity with T. tonsurans suggests that it should be interpreted with caution and ideally used alongside confirmatory tests.

We aim to describe the epidemiology and risk factors for invasive fungal infections (IFI) and invasive mould infections (IMI) in hospitalized hematologic patients within the context of current hematologic therapies. Retrospective observational cohort study conducted on consecutive hematologic patients admitted to a tertiary hospital (2020-2023). Two populations were analysed: the full cohort of hospitalized patients (FC) and the subset of patients for whom mycological testing was specifically requested to rule out an IFI (SC). Proven or probable IFI was classified using European Organization for Research and Treatment of Cancer criteria. Risk factors for IFI and IMI were identified. A total of 1975 patients were included in the FC, whereas 1154 were included in the SC. IFI was diagnosed in 64 patients (65 episodes), and IMI in 43 patients (44 episodes). Aspergillosis was the most common IFI (58.4%), followed by candidemia (18.5%), Pneumocystis jirovecii pneumonia (PJP) (15.4%), mucormycosis (6.2%), and fusariosis (4.6%). Independent risk factors for IFI in the FC included acute leukemia (aOR 2.40, 95% CI 1.37-4.10, P = .002), corticosteroid use (aOR 2.36, 95% CI 1.40-4.03, P = .001) and graft versus host disease (GVHD) (aOR 2.13, 95% CI 0.93-4.46, P = .05). For IMI, risk factors were acute leukemia (aOR 2.71, 95% CI 1.33-5.52, P = .006), corticosteroid use (aOR 1.96, 95% CI 0.98-4.03, P = .05) and chronic lung disease (aOR 2.25, 95% CI 1.06-4.5, P = .02). In the SC, corticosteroid use (aOR 2.45, 95% CI 1.44-4.25, P = .001) was the independent risk factor for IFI, and corticosteroid use (aOR 2.40, 95% CI 1.21-4.91, P = .01) and GVHD (aOR 2.95, 95% CI 1.23-6.52, P = .009) were independent factors associated with IMI. Mortality was significantly higher in IFI patients compared to non-IFI patients (51.6% vs. 20.3%, P < .001). In this new era of haematology, the epidemiology of IFI is shifting, with Pneumocystis, Mucorales, and Fusarium becoming more prevalent. While corticosteroids and GVHD remain key risk factors, factors such as chronic lung disease are increasing its importance. Prolonged neutropenia may have decreased in relevance, likely due to prophylaxis. Preventing PJP has become a new challenge in IFI management.