O(on behalf of the Medical Mycology Committee (CoSM)—Italian Association of Clinical Microbiology (AMCLI)
on behalf of the Medical Mycology Committee (CoSM)—Italian Association of Clinical Microbiology (AMCLI)
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The analytical performance of the new Aspergillus Galactomannan Ag VirCLIA® mono-test (Vircell S.L.) was compared to the Platelia™ Aspergillus Ag ELISA assay (Bio-Rad). Prospective serum and bronchoalveolar lavage (BAL) samples from patients at risk of invasive aspergillosis (IA) were tested using both the Aspergillus Galactomannan Ag VirCLIA® mono-test and the Platelia™ Aspergillus Ag ELISA assay. Concordance, sensitivity, specificity, and positive and negative predictive values were calculated using the manufacturer-recommended cutoff levels. Receiver operating characteristic (ROC) analysis and the Youden index were performed to determine the optimal cutoff. A total of 187 serum samples and 73 BAL samples were analyzed with both assays. The concordance between the Aspergillus Galactomannan Ag VirCLIA® mono-test and the Platelia™ Aspergillus Ag ELISA assay was 87.8%, with a Cohen’s kappa of 0.75. The sensitivity and specificity of the Aspergillus Galactomannan Ag VirCLIA® mono-test were 78.6% and 96.2%, respectively, with positive and negative predictive values of 94.8% and 83.3%. The ROC curve for the Aspergillus Galactomannan Ag VirCLIA® mono-test demonstrated an area under the curve (AUC) of 0.87, and the Youden index at the manufacturer’s established cutoff was 0.73. This new Aspergillus Galactomannan Ag VirCLIA® mono-test exhibited adequate analytical and clinical performance, showing good correlation with the Platelia™ Aspergillus Ag ELISA assay. The single-sample, semi-automated test is user-friendly, allowing small laboratories to perform the test on demand without the need for batch evaluations, providing a useful solution for timely diagnostic support for clinicians.
In this study the activity of Isavuconazole, Voriconazole, Amphotericin B, and Caspofungin against 224 clinical isolates of Aspergillus spp. originating from seven Italian hospitals, was comparatively evaluated with two commercial antifungal susceptibility tests (AST): SensititreTM YeastOneTM (SYO) and MIC Test Strip. More attention was focused on Isavuconazole activity, given the new introduction of the drug in widely distributed antifungal susceptibilities methods in the clinical microbiology lab. The minimum inhibitory concentrations of antifungal drug that can inhibit the growth of pathogen by 90% (MIC90) for Isavuconazole detected by SYO were 0.5, 1, 0.25, and 2 μg/mL for Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, and Aspergillus niger, respectively, whilst they were 0.25, 0.25, 0.5, and 0.75 μg/mL by MIC Test Strip. Essential agreement between the two tested methods for Isavuconazole is 70% for all the species tested, 75.7% for A. fumigatus, 45.2% for A. flavus, 90.6% for A. terreus, and 40% for A. niger. Although the tested strains do not express any phenotypic resistance, MIC results were quite different if tested with microdilution broth or gradient agar method. This is the first Italian multicenter report on Isavuconazole MIC obtained employing the widely used SensititreTM Yeast OneTM (SYO) and MIC Test Strip on clinical isolates of Aspergillus.
Background: Starting from 2018 onwards, several outbreaks of fluconazole‐resistant C. parapsilosis have been reported in many countries worldwide.Objectives: Here we report a retrospective study on C. parapsilosis blood isolates collected over 7 years (2018–2024) in two hospitals in Northern Italy.Patients/Methods: The study involved 169 C. parapsilosis isolates collected from individual hospitalised patients. We assessed the antifungal susceptibility of the isolates, evaluated the presence of mutations in the ERG11 gene and performed multilocus microsatellite typing to highlight the genetic relatedness of the strains. All isolates were also tested for their ability to produce biofilm.Results: Among the 169 clinical isolates, 124 (73.4%) were classified as fluconazole‐resistant C. parapsilosis (FRCP) and 45 (26.6%) as fluconazole‐susceptible (FSCP). ERG11 sequencing highlighted that the most frequent mutation in FRCP is the Y132F (118/124, 95.2%). None of the FSCP carried the Y132F. Microsatellite genotyping showed five major clusters and 13 sub‐clusters, formed by isolates sharing identical genotypes. Sub‐cluster R1 included 96 FRCP carrying the Y132F substitution, isolated from 2018 to 2024 in both hospitals. Interestingly, 99.1% of the FRCP carrying the Y132F mutation were categorised as low biofilm formers, while FRCP carrying other ERG11 mutations were categorised as medium or high biofilm formers.Conclusions: Our results confirmed that Y132F may be mainly responsible for azole resistance in C. parapsilosis and inter‐hospital spread. As we found, recent clinical studies indicate that FRCP isolates responsible for severe outbreaks produce thin biofilms. Mutated and therefore resistant strains may exhibit reduced biofilm production as a protective mechanism.
Background: Trichophyton indotineae, a new emerging pathogen according to the WHO, is known to cause severe forms of tinea. Given that traditional identification methods rely on morphological characteristics, and the morphological distinctions among T. indotineae, T. mentagrophytes, and T. interdigitale are minimal, the adoption of alternative diagnostic techniques, such as RT-PCR or gene sequencing, has become critically important to prevent misidentification. The purpose of this study was firstly to analyze the local epidemiology of dermatophytes isolated and secondly to investigate the presence of T. indotineae among the isolated strains. Methods: Between January 2021 and June 2024, 1096 samples of skin adnexa were analysed. The isolated strains belonging to the genus Trichophyton were submitted to molecular identification by ITS sequencing, and T. indotineae strains were subjected to squalene epoxidase (SQLE) sequencing analysis. Results: Trichophyton rubrum and Trichophyton interdigitale appear to be the most prevalent pathogenic species. Molecular identification reveals four T. indotineae strains (4/87; 4.61%) from Asian patients, which were also characterized by gene mutations associated with terbinafine resistance. Conclusions: This study has made it clear that there is a need to implement basic mycological diagnostics with molecular methods to avoid misidentifications, ensure the correct identification, and evaluate the presence of mutations associated with antifungal drug resistance.
Early diagnosis is one of the main obstacles to timely treatment of Invasive Aspergillosis (IA). The aim of this work, which is part of a multicentre study, was to evaluate the performance of the Aspergillus ELITe MGB® test in detecting Aspergillus spp. DNA in patients with suspected IA according to EORTC/MSG criteria.