Mycopathologia最新文献

Background: Urinary-source candidemia is an uncommon but clinically relevant form of invasive candidiasis, often underrecognized and poorly characterized in the literature.

Methods: Retrospective single-center study of adult patients with candidemia attributed to a urinary source between 2019 and 2023. Eligible cases were identified using predefined attribution criteria, requiring microbiologically confirmed Candida spp. bloodstream infection with significant candiduria by the same species, in the absence of an alternative clinically plausible source.

Results: Among 526 positive blood cultures, 26 fulfilled the predefined criteria for urinary tract source attribution. The median age was 74 years. Most patients had a nephro-urological history, with frequent chronic kidney disease (15, 57.7%), obstructive uropathy (19, 73.1%), indwelling urinary devices (21, 80.8%) and recent urological procedures (19, 73.1%). Type 2 diabetes was present in 50% of patients (13), most receiving SGLT2 inhibitors. The majority presented with fever (23, 88.5%), and sepsis was frequent (14, 53.8%). Urinary symptoms were present in only half of the patients (14, 53.8%). Candida albicans was the most frequent isolate (13, 50%); followed by Candida glabrata (8, 30.8%) and Candida parapsilosis (5, 19.2%), both showing high rates of elevated fluconazole MICs. Empirical therapy was often discordant with final susceptibility. Combination antifungal therapy was used in 26.9% (7). Attributable mortality was 23.1% (6 deaths). Independent predictors of mortality included type 2 diabetes, Barthel Index < 50, therapeutic failure and septic shock.

Conclusions: Candidemia with a presumed urinary tract source primarily affects frail patients with urological comorbidities, often presents with non-specific symptoms and is associated with significant morbidity and mortality. Combination antifungal therapy may be beneficial in selected cases. Early recognition and individualized management are essential to improve outcomes.

Background: Lactobacillus species are essential for vaginal eubiosis; their depletion often leads to dysbiosis, increasing susceptibility to sexually transmitted infections (STIs). This study investigated the prevalence of Candida albicans colonization and its associated factors among HIV-negative adolescent girls and young women (AGYW) in South Africa. Furthermore, STIs associated with C. albicans colonization and Lactobacillus deficiency were investigated.

Methods: Secondary data analysis was performed on 138 HIV-negative AGYW of Eastern Cape province, South Africa. Secondary data included cervico-vaginal detected C. albicans, Lactobacillus species (L. crispatus, L. gasseri or L. jensenii), bacterial vaginosis, human papillomavirus (HPV), Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, herpes simplex virus type 1/2 (HSV-1/2), and Mycoplasma genitalium, and behavioural questionnaires. Univariate and multivariate logistic regression were performed using GraphPad Prism Version 8.0.1.244.

Results: A proportion of 27.58% were positive for C. albicans, and 84.06% tested positive for at least one investigated STI (73.91% for HPV, 31.16% for C. trachomatis, 12.32% for N. gonorrhoeae, 10.87% for T. vaginalis, 7.25% for HSV-1/2, and 5.80% for M. genitalium). Frequent sexual intercourse (more than two times within the past 30 days) was associated with higher odds of C. albicans (OR: 1.84, 95% CI 1.85-3.80, p = 0.036), alcohol consumption (OR: 3.60, 95% CI 1.12-13.23, p = 0.038) and recent vaginal discharge syndrome (OR: 2.67, 95% CI 1.06-6.63, p = 0.005). Deficiency of Lactobacilli among C. albicans-positive AGYW was associated with increased odds of C. trachomatis positivity (OR: 4.37, 95% CI 1.05-17.05, p = 0.047).

Conclusion: HIV-negative AGYW demonstrated a high burden of STIs, with C. albicans positivity associated with alcohol consumption, frequent sexual intercourse, and vaginal discharge syndrome. The absence of Lactobacilli was associated with increased odds of C. trachomatis positivity. Further research is recommended using longitudinal designs, larger sample sizes, and diverse populations to better understand these observations.

Yeasts belonging to the Candida genus typically reside on the mucosal surface and within the respiratory and gastrointestinal tract as commensals. Under conditions of host vulnerability, they can act as opportunistic pathogens, leading to various forms of candidiasis, including candidemia. Such infections can be particularly problematic when caused by isolates that exhibit resistance to antifungal drugs, which are becoming more prevalent in many regions. One hundred and seven samples of Candida spp. were isolated from patients with candidemia in the hospital San Matteo in Pavia (Italy) over a period of 6 years, from 2015 to the first COVID wave in spring 2020. In order to understand the epidemiology of Candida infections in this hospital setting, the isolates were whole-genome sequenced, confirming that most belonged to C. parapsilosis and C. albicans. Comparative genomics revealed that isolates of C. albicans were genomically diverse, indicative of repeated introductions in the hospital from the community. C. parapsilosis isolates on the other hand belonged to two groups of highly similar isolates, representing strains capable of long-term persistence in the hospital. All isolates of the main persistent group were resistant to fluconazoleresulting from the Y132F substitution in ERG11 and the N455D substitution in UPC2, while presenting variable levels of resistance to voriconazole and itraconazole. Interestingly, with the exception of the single isolate susceptible to both voriconazole and itraconazole, all the 61 isolates presented one unreported missense mutation in MRR1 (S1907C).

Microsporum canis is one of the most common zoophilic pathogenic fungi, and infections are typically managed using empirical antifungal therapy. The increasing incidence of M. canis infections has led to a growing demand for antifungal susceptibility assays in clinical settings, particularly in pediatric department, to guide drug selection and to monitor therapeutic responses in highly inflammatory cases. However, susceptibility testing methods rely heavily on sporulation capacity of M. canis, and more than half of the clinical isolates fail to produce sufficient microconidia in commonly-used media for reliable testing.In this study, we evaluated a novel a rice bran medium (RBM) for its ability to enhance microconidia production in clinical isolates of M. canis. RBM demonstrated a significantly greater sporulation-inducing effect than conventional media, including potato dextrose agar (PDA), Sabouraud dextrose agar (SDA), and oatmeal agar (OA), which are commonly used in clinical laboratories. Sporulation efficiency varied with RBM concentrations, with 4% RBM showing the highest efficacy. Under this concentration, abundant microconidia were consistently produced by testing clinical strains after 7-10 days of incubation at 30 ℃ across. These findings suggest that RBM represents a practical and effective alternative medium for promoting sporulation and facilitating antifungal susceptibility in clinical settings.

The rapid expansion of zoonotic sporotrichosis in South America necessitates innovative surveillance strategies to identify natural ecological niches. Roadkill provides a unique, underutilized opportunity to monitor Sporothrix circulation within human-impacted landscapes. We conducted a molecular survey via a triplex probe quantitative real-time PCR (qPCR) assay targeting pathogenic Sporothrix species in 81 roadkilled vertebrates (mammals, birds, and reptiles) collected along highways BR-376 and PR-445 traversing the Atlantic Forest in Paraná, Brazil (2017-2023). Genomic DNA from visceral organs (heart, liver, lung, and spleen) was screened for fungal DNA. Sporothrix DNA was detected in 13.6% (11/81) of the samples. Sporothrix schenckii predominated, identified in wild mammals (Leopardus guttulus, Didelphis albiventris, and Lepus europaeus) and diverse birds (Colaptes melanochloros, Piaya cayana, and Selenidera maculirostris), indicating systemic exposure. Strikingly, S. brasiliensis was detected in avian hosts (Columbina picui, Crypturellus tataupa), challenging the thermal-exclusion hypothesis and implicating birds as potential aerial vectors. Furthermore, S. globosa was found in Dasyprocta spp. and was co-detected with S. brasiliensis in Columbina picui. Notably, a reptile (Oxyrhopus spp.) was positive for S. globosa and S. schenckii, expanding the known host spectrum, potentially via trophic transmission. Although distinguishing transient DNA carriage from active infection requires histopathological validation, these findings suggest that wildlife in fragmented corridors may function as reservoirs, biological amplifiers, or mechanical vectors rather than incidental hosts, reinforcing the blurring boundaries between sylvatic and synanthropic transmission cycles. In this context, integrating roadkill biosurveillance into a One Health framework is vital for tracking environmental pathogen loads and anticipating zoonotic spillover.

Diagnosis of catheter-associated candiduria is limited by absent colony-forming unit (CFU) thresholds and heterogeneous laboratory workflows, complicating patient management. Within a quality-improvement (QI) initiative we aimed to (1) implement and evaluate a standardised quantitative culture (QM) workflow for catheter urine, (2) compare QM with routine semi-quantitative culture (SQM) for CFU detection and reproducibility, and (3) assess whether visible urine aggregates predict Candida spp. presence. From February 2024 to February 2025, we analysed 222 yeast-positive urine samples from 74 catheterised patients. This pilot combined process standardisation, parallel SQM and QM testing, targeted microscopy of aggregate-containing samples, and species identification by CHROMID® Candida agar and MALDI-TOF. Agreement between methods, intra-patient CFU variability over three daily samples, and the predictive value of aggregates were assessed. Aggregates were present in 29/222 samples (13.1%), of which 13 (44.8%) contained Candida spp., mainly C. albicans. No reliable macroscopic features distinguished Candida-positive from -negative aggregates. QM and SQM showed poor agreement (Bowker p < 0.001, κ = 0.17). QM detected growth in samples reported as "sterile" by SQM and provided continuous CFU counts. Cohort-level median QM counts were stable, but 13 patients (17.6%) showed notable variability, with 5 (6.8%) fluctuating > 10³ CFU/mL. Process data suggested batching and variable pre-analytics as contributors to discordance. A standardised QM workflow revealed substantial discordance with SQM and highlighted pre-analytical variability. Visible aggregates are unreliable indicators for Candida spp. presence. Adoption of standardised quantitative culture, systematic microscopy, and structured lab-clinician communication may improve diagnostic consistency; prospective evaluation is warranted.

Neoscytalidium dimidiatum is a non-dermatophyte mold that commonly causes skin and nail infections in tropical regions and often resists conventional antifungal therapies. Because its clinical and laboratory features often resemble dermatophyte infections, diagnosis is frequently delayed and treatment is sometimes inappropriate. We therefore developed a dot-immunobinding assay (Dot-Iba) to detect N. dimidiatum antigens. We generated a highly specific monoclonal antibody, 3E6F7 (MAb 3E6F7), for antigen capture, and used goat anti-mouse Ig conjugated with alkaline phosphatase (AP) as the signal generator. The test pad comprised a test hole, a nitrocellulose membrane (NC), and water-absorbent pads in a vertical flow-through format to allow a rapid antigen-antibody reaction. The assembled system detected N. dimidiatum antigens in vitro with high specificity and yielded visible results within 2 h; its detection limit was 0.9 µg without cross-reactivity to dermatophyte or non-dermatophyte fungi. This rapid, specific, and easy-to-use assay shows strong potential as a diagnostic tool, particularly in settings with limited access to fungal culture or advanced molecular diagnostics, where early, accurate identification is crucial.

Dermatophyte infections have evolved in both clinical presentation and etiological profiles, with chronic, recurrent, and widespread forms becoming increasingly prevalent and therapeutically challenging over the past decade. These infections are predominantly caused by Trichophyton indotineae (ITS genotype VIII), a member of the Trichophyton mentagrophytes complex. The virulence mechanisms of T. indotineae remain poorly understood. To elucidate potential pathogenic factors, we investigated hemolytic and co-hemolytic (CAMP-like) activities in dermatophytes associated with recalcitrant dermatophytosis. A total of 127 isolates (117 T. indotineae, 5 T. rubrum, 3 T. tonsurans, and 2 Microsporum canis) were examined using Columbia agar supplemented with 5% ovine (COA) or equine erythrocytes (CEA). Hemolysis was more consistently observed on COA (119 isolates) than on CEA (44 isolates) following 7-day incubation at 27 °C. Additional incubation at 36 °C up to 7 days was required to enhance hemolysis detection on CEA. Overall, 93.7% of isolates exhibited hemolytic activity, whereas only 3.1% demonstrated co-hemolytic activity. Among T. indotineae isolates, 97.4% were hemolytic. These findings underscore the importance of characterizing virulence traits in dermatophytes. Additional studies are needed to clarify the role of hemolysis in chronic and recalcitrant infections, with the goal of identifying novel therapeutic targets.

Introduction: Invasive fusariosis (IF) is one of the most aggressive mold infections in patients with acute leukemia, characterized by rapid dissemination, high rates of fungemia, and limited antifungal susceptibility. Its impact is particularly severe in middle-income countries, yet single-center data from these settings remain scarce.

Materials and methods: We conducted a retrospective study of all patients with acute leukemia and proven IF, diagnosed according to EORTC/MSG criteria, from January 2011 to August 2023. Demographic, clinical, therapeutic, and outcome variables were analyzed.

Results: Twenty-six patients were identified. Median age was 46.5 years, and 53.8% were female. Acute myeloid leukemia was the most frequent underlying condition. All patients presented with severe neutropenia at diagnosis. Disseminated disease occurred in 84.6% of cases; two patients had isolated fungemia and two had localized skin disease. Cutaneous lesions were present in 73% of patients, and 31% had pulmonary involvement. Antifungal prophylaxis, mainly fluconazole or anidulafungin, was used in 69.2% of cases. Treatment consisted of lipid formulations of amphotericin B, either alone or combined with voriconazole. Thirty-day mortality reached 38.5%. Mortality was significantly higher among patients undergoing re-induction therapy, whereas those who had received antifungal prophylaxis exhibited lower mortality.

Discussion: IF in acute leukemia was associated with extensive dissemination and substantial early mortality. Mortality rates were higher in patients in re-induction therapy and lower in those who received antifungal prophylaxis. The role of combination antifungal therapy requires further investigation.

To date, research on the efficacy of intraspecific molecular markers for the clonal fungal species Trichophyton rubrum, particularly studies that validate these markers through phenotypic characterization, has remained extremely limited. This study re-evaluated and confirmed the population structure of T. rubrum in southwestern Guizhou, China, by employing both the terg_02941 gene-encoding a protein of unknown function-and the conventional molecular marker rpb2. Integrated analyses incorporating clinical, physiological, and antifungal susceptibility data were conducted to investigate potential associations between distinct genetic lineages and their corresponding phenotypes. Phylogenetic analysis based on terg_02941 classified 324 Guizhou isolates into two major genetic lineages: ST1 (166 isolates) and ST2 (158 isolates), with ST1 forming a distinct lineage supported by moderate bootstrap values. In the rpb2-based phylogeny, two Guizhou isolates harboring non-synonymous mutations clustered within the ST1 group as a separate sublineage, further supporting the genetic stability or adaptive advantage of the ST1 population. Clinically, the ST1 lineage exhibited reduced prevalence among individuals under 15 years and over 60 years of age and showed diminished colonization of the human body's midline anatomical sites (P < 0.01). Physiologically, the ST1 population demonstrated lower tolerance to low temperature and acidic conditions. Notably, colonies of the ST1 lineage lacked red pigment production and predominantly exhibited yellow pigmentation (P < 0.001). Although no significant differences were observed in the geometric mean MIC values or the proportion of non-wild-type strains between the two lineages, pigment formation was negatively correlated with the degree of antifungal resistance (DDR) (P < 0.001), with classical red-pigmented strains showing the highest frequency of susceptibility. Collectively, the two globally distributed genetic lineages of T. rubrum in Guizhou exhibit both shared polymorphic traits and lineage-specific phenotypic tendencies. The more stable ST1 lineage appears to have achieved persistent colonization of human skin through a process of phenotypic streamlining, whereas the ancestral ST2 lineage displays broader phenotypic diversity, offering potential evidence for an ecological transition from environmental reservoirs to human host adaptation.