Mycopathologia最新文献

Fungal infections pose an increasing threat to public health. New pathogens and changing epidemiology are a pronounced risk for nosocomial outbreaks. To investigate clonal transmission between patients and trace the source, genotyping is required. In the last decades, various typing assays have been developed and applied to different medically important fungal species. While these different typing methods will be briefly discussed, this review will focus on the development and application of short tandem repeat (STR) genotyping. This method relies on the amplification and comparison of highly variable STR markers between isolates. For most common fungal pathogens, STR schemes were developed and compared to other methods, like multilocus sequence typing (MLST), amplified fragment length polymorphism (AFLP) and whole genome sequencing (WGS) single nucleotide polymorphism (SNP) analysis. The pros and cons of STR typing as compared to the other methods are discussed, as well as the requirements for the development of a solid STR typing assay. The resolution of STR typing, in general, is higher than MLST and AFLP, with WGS SNP analysis being the gold standard when it comes to resolution. Although most modern laboratories are capable to perform STR typing, little progress has been made to standardize typing schemes. Allelic ladders, as developed for Aspergillus fumigatus, facilitate the comparison of STR results between laboratories and develop global typing databases. Overall, STR genotyping is an extremely powerful tool, often complimentary to whole genome sequencing. Crucial details for STR assay development, its applications and merit are discussed in this review.

We aimed to develop and validate a Loop-mediated Isothermal Amplification (LAMP) assay to Sporothrix brasiliensis. LAMP reaction was developed using six primers designed based on calmodulin gene. In the LAMP reaction, we tested twenty isolates of S. brasiliensis from animals and humans, along with ten tissue samples extracted from the left footpad of mice that had been experimentally infected with S. brasiliensis. In addition, it included DNA samples from various other fungal species for specificity evaluation. All S. brasiliensis isolates yielded positive results in the LAMP, and the limit of DNA detection was 1 ng/μL. All murine samples were positive in the test while DNA from other fungal species were all negative, resulting in 100% of sensitivity and specificity of primers. LAMP diagnosis technique is a promising alternative to sporotrichosis diagnosis, in a simple and cost-effective way. Further studies are warranted to validate this technique using animal model samples obtained from both humans and animals.

Introduction: New diagnostic methods and antifungal strategies may improve prognosis of mucormycosis. We describe the diagnostic value of metagenomic next⁃generation sequencing (mNGS) and identify the prognostic factors of mucormycosis.

Methods: We conducted a retrospective study of hematologic patients suffered from mucormycosis and treated with monotherapy [amphotericin B (AmB) or posaconazole] or combination therapy (AmB and posaconazole). The primary outcome was 84-day all-cause mortality after diagnosis.

Results: Ninety-five patients were included, with "proven" (n = 27), "probable" (n = 16) mucormycosis confirmed by traditional diagnostic methods, and "possible" (n = 52) mucormycosis with positive mNGS results. The mortality rate at 84 days was 44.2%. Possible + mNGS patients and probable patients had similar diagnosis processes, overall survival rates (44.2% vs 50.0%, p = 0.685) and overall response rates to effective drugs (44.0% vs 37.5%, p = 0.647). Furthermore, the median diagnostic time was shorter in possible + mNGS patients than proven and probable patients (14 vs 26 days, p < 0.001). Combination therapy was associated with better survival compared to monotherapy at six weeks after treatment (78.8% vs 53.1%, p = 0.0075). Multivariate analysis showed that combination therapy was the protective factor (HR = 0.338, 95% CI: 0.162-0.703, p = 0.004), though diabetes (HR = 3.864, 95% CI: 1.897-7.874, p < 0.001) and hypoxemia (HR = 3.536, 95% CI: 1.874-6.673, p < 0.001) were risk factors for mortality.

Conclusions: Mucormycosis is a life-threatening infection. Early management of diabetes and hypoxemia may improve the prognosis. Exploring effective diagnostic and treatment methods is important, and combination antifungal therapy seems to hold potential benefits.

Invasive candidiasis and candidemia remain a significant public health concern. The European Confederation of Medical Mycology (ECMM) conducted three pan-European multicentre studies from 1997 to 2022 to investigate various aspects of invasive Candida infections. These studies revealed shifting trends in Candida species distribution, with an increase of non-albicans Candida species as causative pathogens, increasing rates of antifungal resistance, and persistently high mortality rates. Despite advancements in antifungal treatment, the persistently high mortality rate and increasing drug resistance, as well as limited drug access in low-income countries, underscore the need for continued research and development in the treatment of Candida infections. This review aims to summarize the findings of the three completed ECMM Candida studies and emphasize the importance of continued research efforts. Additionally, it introduces the upcoming ECMM Candida IV study, which will focus on assessing candidemia caused by non-albicans Candida species, including Candida auris, investigating antifungal resistance and tolerance, and evaluating novel treatment modalities on a global scale.

The clinical spectrum of invasive pulmonary aspergillosis (IPA) has expanded in recent decades. A large group of patients admitted to intensive care units (ICU) is indeed susceptible to the development of IPA. Although timely diagnosis and antifungal therapy of IPA in this expanding population is crucial to prevent IPA-related deaths, the magnitude of the favorable prognostic impact of antifungal therapy is difficult to measure precisely. In our opinion, the development of standardized research definitions could have favorable implications for further improving our ability both to measure the favorable effect of antifungal treatment and to prevent IPA-related death in ICU patients.

Context: Allergic bronchopulmonary mycoses (ABPM) can be due to molds other than Aspergillus fumigatus in patients with cystic fibrosis (pwCF). We aimed to develop immunoassays for the detection of specific IgE (sIgE) directed against five fungal species involved in ABPM: Aspergillus terreus, Scedosporium apiospermum, Lomentospora prolificans, Rasamsonia argillacea, and Exophiala dermatitidis.

Materials and methods: Serum samples (n = 356) from 238 pwCF, collected in eight CF care centers in France, Germany, and Italy, were analyzed by dissociated enhanced lanthanide fluorescent immunoassay (DELFIA®) to assess levels of sIgE directed against antigenic extracts of each fungus. Clinical, biological, and radiological data were collected for each episode. One hundred serum samples from healthy blood donors were used as controls. Sera were classified into four groups depending on the level of sIgE according to the quartile repartition calculated for the pwCF population. A score of 4 for values above the 3rd quartile corresponds to an elevated level of sIgE.

Results: PwCF showed higher levels of sIgE than controls. Based on criteria from the ABPA-ISHAM working group, with an additional criterion of "a sIgE score of 4 for at least one non-A. fumigatus mold", we were able to diagnose six cases of ABPM.

Conclusions: Using 417 IU/mL as the threshold for total IgE and the same additional criterion, we identified seven additional pwCF with "putative ABPM". Detection of sIgE by DELFIA® showed good analytical performance and supports the role played by non-A. fumigatus molds in ABPM. However, commercially available kits usable in routine practice are needed to improve the diagnosis of ABPM.

Background: Galactomannan (GM) testing using Platelia Aspergillus enzyme immunoassay (Platelia AGM) from bronchoalveolar lavage fluid (BALF) aids in early diagnosis of invasive pulmonary aspergillosis (IPA). Globally, only a minority of laboratories have the capability to perform on-site GM testing, necessitating accessible and affordable alternatives. Hence, we conducted a comparative evaluation of the new clarus Aspergillus GM enzyme immunoassay prototype (clarus AGM prototype) with Platelia AGM using BALF samples.

Methods: This is a single-center, prospective, cross-sectional study, where Platelia AGM testing was routinely performed followed by clarus AGM prototype testing in those with true positive or true negative AGM test results according to the 2020 EORTC/MSG and the 2024 FUNDICU consensus definitions. Descriptive statistics, ROC curve analysis, and Spearman's correlation analysis were used to evaluate analytical performance of the clarus AGM prototype assay.

Results: This study enrolled 259 adult patients, of which 53 (20%) were classified as probable IPA, while 206 did not fulfill IPA-criteria. Spearman's correlation analysis revealed a strong correlation between the two assays (rho = 0.727, p < 0.001). The clarus AGM prototype had a sensitivity of 96% (51/53) and a specificity of 74% (153/206) for differentiating probable versus no IPA when using the manufacturer recommended cut-off. ROC curve analysis showed an AUC of 0.936 (95% CI 0.901-0.971) for the clarus AGM prototype, while the Platelia AGM yielded an AUC of 0.918 (95% CI 0.876-0.959).

Conclusions: Clarus AGM prototype demonstrated a strong correlation and promising test performance, comparable to Platelia AGM, rendering it a viable alternative in patients at risk of IPA.

Cat-transmitted sporotrichosis is caused by the emerging fungal pathogen Sporothrix brasiliensis and constitutes a significant public health issue that affects people living in resource-poor urban centers in Brazil. The lack of knowledge about transmission dynamics makes it difficult to propose public health policies to contain the advance of sporotrichosis. We describe the recent emergence of 1,176 cases of sporotrichosis in cats (2016 to 2021) in the metropolitan region of Recife, Brazil, leading to significant zoonotic transmission and an overwhelming occurrence of S. brasiliensis as the etiological agent. Most cases were from cats in the cities of Olinda (408/1,176; 34.70%), Jaboatão dos Guararapes (332/1,176; 28.23%), and Recife (237/1,176; 20.15%). Molecular typing using amplified fragment length polymorphism (EcoRI-GA/MseI-AG) revealed low polymorphic information content (PIC = 0.2499) and heterozygosity (H = 0.2928), typical of an outbreak scenario. Dendrogram and multivariate cluster analysis revealed that isolates from Pernambuco are closely related to Rio de Janeiro isolates. We report a substantial occurrence of MAT1-2 idiomorphs in the metropolitan region of Recife (0:60 ratio; χ² = 60.000, P < 0.0001). The limited population differentiation and genetic diversity of the isolates from Pernambuco suggest a recent introduction, possibly via a founder effect, from the parental population in Rio de Janeiro. Our findings emphasize the critical importance of molecular surveillance of S. brasiliensis for outbreak response. A comprehensive one-health strategy is mandatory to control the spread of cat-transmitted sporotrichosis driven by S. brasiliensis, encompassing sanitary barriers, quick diagnosis, and treatment.

Candida auris is an emerging multi-drug resistant yeast that can cause life-threatening infections. A recent report clarified the ability of C. auris to form a biofilm with enhanced drug resistance properties in the host skin's deep layers. The formed biofilm may initiate further bloodstream spread and immune escape. Therefore, we propose that secreted chemicals from the biofilm may facilitate fungal pathogenesis. In response to this interaction, the host skin may develop potential defensive mechanisms. Comparative transcriptomics was performed on the host dermal cells in response to indirect interaction with C. auris biofilm through Transwell inserts compared to planktonic cells. Furthermore, the effect of antifungals including caspofungin and fluconazole was studied. The obtained data showed that the dermal cells exhibited different transcriptional responses. Kyoto Encyclopedia of Genes and Genomes and Reactome analyses identified potential defensive responses employed by the dermal cells and potential toxicity induced by C. auris. Additionally, our data indicated that the dominating toxic effect was mediated by ferroptosis; which was validated by qRT-PCR, cytotoxicity assay, and flow cytometry. On the other hand, the viability of C. auris biofilm was enhanced and accompanied by upregulation of MDR1, and KRE6 upon interaction with dermal cells; both genes play significant roles in drug resistance and biofilm maturation, respectively. This study for the first-time shed light on the dominating defensive responses of human dermal cells, microbe colonization site, to C. auris biofilm and its toxic effects. Further, it demonstrates how C. auris biofilm responds to the defensive mechanisms developed by the human dermal cells.

Since its inception in 2002, the EUCAST Antifungal Susceptibility Testing Subcommittee (AFST) has developed and refined susceptibility testing methods for yeast, moulds and dermatophytes, and established epidemiological cut-off values and breakpoints for antifungals. For yeast, three challenges have been addressed. Interpretation of trailing growth in fluconazole susceptibility testing, which has been proven without impact on efficacy if below the 50% endpoint. Variability in rezafungin MIC testing due to laboratory conditions, which has been solved by the addition of Tween 20 to the growth medium in E.Def 7.4. And third, interpretation of MICs for rare yeast with no breakpoints, where recommendations have been established for MIC-based clinical advice. For moulds, refinements include the validation of spectrophotometer reading for A. fumigatus to facilitate objective MIC determination, and for dermatophytes the establishment of a microdilution method with automated reading and a selective medium to minimise the risk of contaminations. Recent initiatives involve development and validation of agar-based screening assays for detection of potential azole and echinocandin resistance in A. fumigatus and Aspergillus species, respectively, and of terbinafine resistance in Trichophyton species. Moreover, the development of a EUCAST guidance document for molecular resistance testing represents an advancement, particularly for identifying target gene alterations associated with resistance. In summary, EUCAST AFST continues to play a pivotal role in standardizing AFST and facilitating accurate interpretation of susceptibility data for clinical decision-making. Adoption of EUCAST breakpoints for commercial test methods, however, requires thorough validation to ensure concordance with EUCAST reference testing species-specific MIC distributions.