Objective To initially evaluate the feasibility and potential clinical value of high-resolution computed tomography (HRCT)-based three-dimensional (3D) airway reconstruction combined with computational spray simulation for guiding bronchoscopic amphotericin B delivery in patients with chronic pulmonary aspergillosis (CPA).Methods This multicenter, prospective cohort study with an expanded historical control was conducted. Patients in the prospective reconstruction cohort received HRCT-based 3D airway reconstruction combined with computational spray simulation to guide bronchoscopic amphotericin B delivery. Historical controls consisted of eligible CPA patients with complete clinical, imaging, treatment, adverse-event, and 6 month follow-up data who had received conventional bronchoscopic amphotericin B administration before implementation of the reconstruction-guided approach.Results A total of 10 patients in the reconstruction cohort and 30 historical controls were included. Baseline characteristics were generally comparable between groups, although fatigue was more frequent in the historical control cohort. At 6 months after treatment, the reconstruction cohort showed lower total St. George's respiratory questionnaire (SGRQ) scores than the historical control cohort. And SGRQ scores decreased significantly after treatment in each group, with a decrease of well over four points from baseline. More favourable clinical and radiographic responses and fewer adverse events were observed in the reconstruction cohort.Conclusion The integrated reconstruction-guided strategy may provide a feasible strategy for optimizing bronchoscopic amphotericin B delivery in CPA. Given the historical-control design, small intervention cohort and potential residual confounding, these preliminary findings should be interpreted as exploratory and require confirmation in larger prospective controlled studies.
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:Fluconazole tolerance is an emerging phenotype in Candida albicans bloodstream infections, but its relationship to multilocus sequence typing (MLST) lineages and virulence traits is unclear. OBJECTIVES:To investigate the relationships among MLST genotypes, fluconazole tolerance, and virulence phenotypes in C. albicans bloodstream isolates. METHODS:179 C. albicans bloodstream isolates collected from three hospitals in southern Taiwan (2013-2020) were evaluated. Fluconazole tolerance was quantified as the fraction of growth within the inhibition zone (FoG20) using the diskImageR pipeline. Phenotypic profiling included quantification of biofilm biomass and extracellular hydrolytic enzymes. Genetic relatedness was determined via MLST. RESULTS:The cohort exhibited significant fluconazole tolerance with a mean FoG20 of 0.29 ± 0.19. FoG20 weakly correlated with biofilm biomass (r = 0.218, p = 0.003). MLST identified 169 unique diploid sequence types with 14 clades and 25 clonal complexes (CCs). The high fluconazole tolerance phenotype was broadly distributed across genetically diverse lineages, although clade 16 showed higher mean FoG20 (0.39) (p = 0.003) and biofilm biomass (0.83) (p = 0.039). In multivariable analysis, clade 16 (aOR 2.86; 95% CI 1.08-7.56; p = 0.034) and protease activity (aOR 2.65; 95% CI 1.24-5.64; p = 0.012), but not biofilm biomass (p = 0.142), were independently associated with high tolerance. High tolerance showed a borderline association with 14-day mortality (aOR 2.56; 95% CI 0.99-6.62; p = 0.052). CONCLUSIONS:Fluconazole tolerance in C. albicans was distributed across diverse lineages, suggesting convergent adaptation. Clade 16 and protease activity were independently associated with tolerance. Given the observed trend toward an association between high tolerance and 14-day mortality, future mechanistic studies and larger clinical outcome studies are warranted.
BACKGROUND:Human skin is naturally exposed to diverse fungi. New taxa, including species with unknown pathogenic potential, continue to be isolated from human skin. OBJECTIVE:To characterize a hitherto unknown hyphomycete isolated from human eczema and to assess its habitat and pathogenic abilities. METHODS:A broad panel of culture conditions was used for morphological examination and physiological testing. Nucleotide ribosomal ITS and LSU sequences were analyzed separately by BLASTn to identify the closest relatives, and a combined ITS-LSU dataset was used for phylogenetic inference. RESULTS:The isolate grew well on common mycological agars at 26°C and was not inhibited by 0.4 g/L cycloheximide. Colonies were flat, with a beige obverse and sparse aerial mycelium. Intercalary, round to subglobose spores developed within the hyphae, and submerged hyphae in cultures older than 4 weeks transformed into chains of spores consistent with chlamydospores. Neither microconidia, macroconidia, nor ascomata were observed. The isolate showed urease, keratinolytic, proteolytic, lipolytic and cellulolytic activity. It grew at 5°C and tolerated up to 6% NaCl; susceptibility to terbinafine was reduced. Phylogenetically, the isolate formed a distinct lineage branching basally to Pseudogeomyces, separated from related taxa by a distance comparable to that between Geomyces and Solomyces. CONCLUSIONS:Dermkielia gen. nov. (IF 905143) is introduced with Dermkielia cavawata sp. nov. (IF 905164) as the type species. Related ITS sequences in NCBI GenBank suggest that additional species of Dermkielia may be discovered. Dermkielia cavawata is presumably geophilic and possibly linked to forest ecosystems, but it possesses traits that may facilitate opportunistic colonization of human keratinized tissue.
