Mycopathologia最新文献

Mucormycosis is an invasive fungal infection, caused by fungi of the order Mucorales, and it is associated with high morbidity and mortality. The epidemiology of mucormycosis is evolving. The incidence, underlying risk factors, clinical presentation, as well as the responsible mucoralean agents, vary by geographic region. The estimated incidence in developed countries ranges from less than 0.06 to 0.3 cases per 100,000 population per year, while in India, it reaches approximately 14 cases per 100,000 population per year, which is about 80 times higher. In European countries the estimated incidence ranges from less than 0.04 to 0.12 per 100,000 population per year. Diabetes mellitus (DM) is the leading underlying disease globally. In Europe, hematological malignancies are the most common risk factor for mucormycosis, while in Asia diabetes predominates. The rhino-cerebral form of mucormycosis is most commonly seen in patients with DM, whereas pulmonary mucormycosis in patients with hematological malignancies and transplants. The most common species globally is Rhizopus arrhizus, whereas new emerging species only occasionally cause infection in Europe. However, vigilance is required, as they may raise concerns-especially in light of climate change- due to their potential to cause serious infections in both immunocompetent and immunosuppressed individuals.

Introduction: Phaeohyphomycoses are uncommon and poorly understood opportunistic fungal infections, characterized by a wide spectrum of clinical manifestations ranging from localized skin lesions to disseminated disease. Most frequent genera are Alternaria, Cladophialophora, Exophiala or Curvularia. Less common ones, such as Verruconis gallopava, initially described as responsible of encephalitis of turkeys, pose significant challenges for diagnosis and treatment.

Material and methods: Following the description of a clinical case, we performed a comprehensive review of 48 cases of V. gallopava infection, a rarely reported species from 1986 to 2024.

Results: Solid organ transplant recipients and patients with hematological malignancies are the population most at-risk. Clinical presentation is nonspecific but can be divided in two main entities, pulmonary and cerebral localizations. This later is associated with a mortality rate over 80% and was significantly more frequently reported in liver transplant recipients (p = 0.03). When tested, ß-D-glucans were positive in all cases. Antifungal susceptibility testing demonstrated low MICs for amphotericin B and all azoles but isavuconazole and fluconazole. Clinical outcomes support the use of amphotericin B, voriconazole, itraconazole and posaconazole as valid treatment options.

Discussion: It is not known whether the cerebral cases are primary or secondary to pulmonary lesions. The indolent pulmonary lesions should prompt a complete work-up including biopsy with pathology and mycology expertise since the differential diagnosis is a cancer lesion.

Background: With the rapid development of the economy and changes in lifestyle in recent years, the epidemiological pattern of dermatophytosis has changed. We analyzed the epidemiological features of dermatophytosis in a hospital in Hangzhou from 2018 to 2023.

Methods: Data from patients with culture-positive dermatophytosis were obtained from the Laboratory Information System of the Mycology Laboratory of our hospital. Dermatophyte isolates were mainly identified by macroscopic and microscopic features of the colonies.

Results: There were 32,786 patients with culture-positive dermatophytosis during the 6-year period, including 16,789 male patients and 15,990 female patients. Patients' ages ranged from 1 month to 97 years. Tinea unguium accounted for the largest proportion (14,879, 45.38%), which was mainly prevalent among females (8946, 60.13%). Significant gender differences were observed in all clinical types of dermatophytosis, except for tinea pedis. In total, 15,486 (47.73%) patients aged 21-40 years. The median age of patients with tinea manum and tinea capitis was the highest (49 years) and the lowest (5 years), respectively. Nine species of isolated dermatophytes were identified, of which Trichophyton rubrum accounted for 90.20% (29,573 cases). M. canis accounted for 66.80% of isolated dermatophytes from tinea capitis. The isolation rates of zoophilic species were 43.41% in tinea faciei and 18.90% in tinea corporis.

Conclusion: T. rubrum was absolutely predominant agent of dermatophytosis except tinea capitis in which M. canis was the most common organism. The prevalence of zoophilic dermatophytes has increased in tinea faciei and tinea corporis. Tinea unguium was the major clinical form of dermatophytosis, and it was more prevalent among females. The onset peak of dermatophytosis was in the age group of 21-40 years, except for tinea capitis.

Background: The study of Paracoccidioides spp. faces significant challenges due to limitations inherent in the molecular biology techniques employed. Recently, new species were described whose geographical and genetic distributions were investigated. The phylogenetic studies have revealed that genotypes originally thought to be exclusive in specific regions from South American countries are now being found in other areas of the continent. This finding indicates a broader geographic distribution of these genotypes than previously recognized.

Objective: To evaluate two molecular biology techniques employed to identify genotypes of Paracoccidioides spp. strains from a Brazilian culture collection previously identified only by mycological methods.

Methods: DNA samples from 35 Paracoccidioides spp. strains maintained in a Brazilian culture collection were subjected to amplification and enzymatic digestion with PCR-RFLP of tub1 gene, followed by sequencing of gp43 Exon 2 loci. Strains with species identification discrepancies had their tub1 sequences determined to verify possible nucleotide mutations.

Results: The genotypic characterization of Paracoccidioides spp. using PCR-RFLP of the tub1 gene identified 22 isolates as P. brasiliensis sensu stricto, two as P. americana, four as P. restrepiensis, and eight as P. lutzii. Sequencing of the gp43 Exon 2 loci revealed discrepancies in the identification of four P. venezuelensis isolates, previously characterized as P. brasiliensis sensu stricto by PCR-RFLP of tub1. The sequencing of tub1 from P. brasiliensis sensu stricto and P. venezuelensis isolates revealed nucleotide differences in the pyrimidine class (C and T) in their sequences, specifically at the position 176 bp.

Conclusion: These molecular tools were able to establish the genetic diversity within the Paracoccidioides genus, crucial for taxonomy and epidemiology studies. The finding of presence of P. venezuelensis in Brazil, previously thought to be exclusive to Venezuela, highlights genetic connections and evolutionary divergences within the genus. While the PCR-RFLP of tub1technique showed limitations in identifying P. venezuelensis, sequencing of the gp43 Exon 2 loci was able to accurately identify this genotype. Thus, our findings contribute to the understanding of the molecular epidemiology of PCM and emphasize the need for precise species characterization in mycological research.

Vaginal candidiasis (VC) is a prevalent condition among women of reproductive age and poses a significant global public health challenge. However, the disease is often diagnosed and treated without mycological information. We investigated the epidemiology, laboratory diagnostics, and antifungal susceptibility of VC. We included 300 women from Çukurova University Obstetrics and Gynecology outpatient clinic in Adana, Türkiye. Participants underwent a health survey and provided vaginal swab samples for microscopic examination and fungal culture. The microscopic analysis involved wet-mount and gram-stained slides, whereas fungal identification involved CHROMAgar Candida, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and real-time polymerase chain reaction high-resolution melting analysis (RT-PCR HRMA). Antifungal susceptibility tests were conducted at pH 7 and 4 using the CLSI document M44-A2. Of the 106 women with positive fungal cultures, 86.8% were diagnosed with VC, whereas 13.2% showed Candida colonization. Among those with VC, 55.4% had acute and 44.6% had recurrent VC; a family history of allergies increased the risk for both types. We recovered 115 yeast isolates, predominantly C. albicans, C. glabrata, and C. krusei. Diagnostic accuracy of CHROMAgar Candida was 91.3% for the most common isolates, and HRMA was consistent in differential diagnosis. Antifungal resistance varied with pH; susceptibility to fluconazole, itraconazole, and ketoconazole decreased at pH 4, whereas susceptibility to miconazole increased. Our findings underscore the need for a diagnostic algorithm and enhanced collaboration between clinicians and microbiologists to improve VC management. Recommendations include using Gram staining, CHROMAgar Candida, MALDI-TOF MS, and antifungal susceptibility tests at both pH levels.

Lodderomyces elongisporus, first isolated in 1952, has increasingly been recognized as a significant pathogen, with a notable rise in human infections since the 1970s. Initially misidentified as Candida parapsilosis due to morphological similarities, L. elongisporus has now been conclusively established as a distinct species, largely due to advancements in molecular biology, particularly DNA sequencing. This review traces the detection history of L. elongisporus, from the earliest documented cases to the most recent reports, underscoring its role as a causative agent in human infections. It also explores therapeutic strategies that have demonstrated efficacy, alongside instances of environmental contamination reported in international literature. A critical evaluation of diagnostic methodologies essential for precise identification is provided, including culture-based techniques such as colony morphology on Sabouraud Dextrose Agar (SDA) and chromogenic media, coupled with microscopic assessments using Lactophenol Cotton Blue (LPCB) and Gram staining. The ultrastructure of L. elongisporus, as observed under Scanning Electron Microscopy (SEM), is also discussed. Furthermore, non-culture-based diagnostics, such as sugar utilization tests (API 20C AUX and the innovative in-house arabinose-based "Loddy" test) and antifungal susceptibility profiling, are reviewed, with a particular focus on molecular tools like ITS-DNA sequencing and MALDI-TOF MS, which, despite their higher costs, offer unparalleled specificity. The accurate distinction and characterization of L. elongisporus are paramount, particularly in vulnerable and immunocompromised patients, where misdiagnosis can lead to severe consequences. This review advocates for intensified research efforts to develop more accessible diagnostic tools and deepen our understanding of this emerging pathogen, ultimately aiming to improve patient outcomes.

Vulvovaginal candidiasis (VVC) is a prevalent gynecological infection characterized by high incidence and recurrent episodes, causing significant distress in women. This study aims to assess the effectiveness of different clotrimazole and fluconazole treatment regimens for severe vulvovaginal candidiasis (SVVC). A retrospective analysis was conducted on 1303 cases of SVVC among first-time visitors to the gynecology outpatient department at Peking University Shenzhen Hospital between January 2013 and December 2022. Vaginal secretions were systematically collected for fungal culture, with species identification conducted using Chromogenic culture medium and API Candida test reagents. Mycological cure rates were assessed at days 7-14, days 25-35, and day 35 to 6 months after treatment. The three-dose clotrimazole regimen demonstrated significantly higher mycological cure rates (85.7%, 80.0% and 74.6% at three follow-up periods, respectively) compared to the two-dose clotrimazole regimen (76.0%, 61.6%, and 59.8%, all P < 0.05). The three-dose fluconazole regimen showed no significant difference to three-dose clotrimazole regimen, with cure rates of 82.8%, 79.3%, and 75.9% (all P > 0.05). The two-dose fluconazole regimen had cure rates of 74.3%, 56.4% and 51.1%, with no significant difference from two-dose clotrimazole regimen at days 7-14 and 25-35, but lower than three-dose fluconazole regimen at days 25-35 and 35 to 6 months. The three-dose clotrimazole regimen demonstrated higher cure rates in Candida albicans and non-albicans Candida SVVC cases than two-dose regimen. These findings suggest that three-dose antifungal regimens may be more efficacious than two-dose regimens for SVVC. The three-dose clotrimazole regimen could serve as a promising alternative for SVVC management.

Dermatophytosis is a very common superficial mycosis, but there are few studies about the human immune response to dermatophytes. We aim to analyze the in situ expression of TNF-α and IL-10 in human dermatophytosis. Expression of TNF-α and IL-10 were evaluated in skin samples from 10 patients with dermatophytosis and 12 healthy subjects using an immunohistochemistry assay. TNF-α and IL-10 were significantly elevated in lesions from patients with dermatophytosis compared to healthy controls. These data illustrate the balance of pro- and anti-inflammatory cytokines suggesting Trichophyton rubrum infection could control the local immune response.

In the last few years, next-generation sequencing (NGS) has emerged as a technology for laboratory diagnosis of many culture-negative infections and slow-growing microorganisms. In this study, we describe the use of metagenomic NGS (mNGS) for rapid diagnosis of T. marneffei infection in a 37-year-old renal transplant recipient who presented with chronic pneumonia syndrome. Bronchoalveolar lavage for mNGS was positive for T. marneffei sequence reads. Prolonged incubation of the bronchoalveolar lavage revealed T. marneffei colonies after 6 days of incubation. Analysis of 23 cases of T. marneffei infections in renal transplant recipients from the literature revealed that the number of cases ranged from 1 to 4 cases per five years from 1990 to 2020; but increased rapidly to 9 cases from 2021 to 2023, with 7 of them diagnosed by NGS. Twenty of the 23 cases were from T. marneffei-endemic areas [southern part of mainland China (n = 9); Hong Kong (n = 4); northeastern India (n = 2); Indonesia (n = 1) and Taiwan (n = 4)]. For the 3 patients from non-T. marneffei-endemic areas [United Kingdom (n = 2) and Australia (n = 1)], they had travel histories to China and Vietnam respectively. The time taken for diagnosis by mNGS [median 1 (range 1 to 2) day] was significantly shorter than that for fungal culture [median 6 (range 3 to 15) days] (P = 0.002). mNGS is useful for picking up more cases of T. marneffei infections in renal transplant recipients as well as providing a rapid diagnosis. Talaromycosis is an emerging fungal infection in renal transplant recipients.