Medical mycology最新文献

Despite the severe impact of uncommon yeast fungal infections and the pressing need for more research on the topic, there are still few studies available on the identification, epidemiology, and susceptibility profile of those pathogens. The aims of the current study were to define the profile of uncommon yeast species at Fattouma Bourguiba University Hospital using phenotypic, molecular, and proteomic methods and to study their antifungal susceptibility profile. Pre-identified uncommon yeast species were collected from 2018 to 2021. These isolates were further identified using phenotypic methods (ID32C® system and Vitek2® YST), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), and sequencing. The antifungal susceptibility profile was studied using the reference CLSI broth microdilution method. In total, 30 strains were collected during the study period. Referring to the sequencing, the most isolated uncommon species were Saprochaete capitata, Candida lusitaniae, Candida kefyr, Candida inconspicua, and Candida guilliermondii. A total of 90% of isolates were correctly identified by MALDI-TOF MS compared to 76.7% and 63.3% by ID32® C and VITEK® 2 YST, respectively. The isolated species showed variable responses to antifungals. Candida guilliermondii showed increased azole minimum inhibitory concentrations. Misidentification of uncommon yeast species was common using commercial phenotypic methods. The high percentage of concordance of MALDI-TOF results with sequencing highlights its high performance and usefulness as a routine diagnosis tool.

This was a cross-sectional study on the availability of laboratory infrastructure and capacity for the diagnosis of invasive fungal diseases in 24 public hospitals in Vietnam in 2023. Among the hospitals surveyed, 66.7% (14/21) had specialized personnel assigned for mycology testing, and 95.8% (23/24) had a separate microbiology laboratory space. Microscopy and culture methods are available in nearly all laboratories for isolate identification. Antifungal susceptibility testing is only performed for yeasts in 16/24 (66.7%) laboratories. Non-culture methods are hardly used in laboratories. Strengthening local laboratory capacities is essential to meeting health needs in these endemic regions.

Zoonotic sporotrichosis caused by Sporothrix brasiliensis is an emerging mycosis in Latin America. One of the problems to quickly treat infected animals and break the transmission chain is associated with the time-consuming gold-standard diagnosis method (culture). We aimed to evaluate a species-specific polymerase chain reaction (PCR) for the diagnosis of sporotrichosis caused by S. brasiliensis using non-invasive samples. We performed a retrospective cross-sectional study using samples collected with swabs from humans and cats with clinical suspicion of sporotrichosis. Deoxyribonucleic acid (DNA) was extracted using a commercial kit, and a species-specific PCR for S. brasiliensis detection was performed. One hundred ten samples were included. PCR showed a good concordance with culture (86% of agreement) for human and cat samples (Kappa coefficient = 0.722, and 0.727, respectively). In conclusion, our data shows that this adapted PCR using non-invasive samples can be applied to sporotrichosis diagnosis, being a good alternative mainly in regions with a lack of mycologists to identify the fungus in culture, contributing to the control of this emergent zoonosis.

Itraconazole (ITZ) is the most used drug to treat feline sporotrichosis; however, little is known about its pharmacokinetics in cats with this mycosis. The aim of this study was to determine plasma ITZ concentrations in cats with sporotrichosis treated with ITZ as monotherapy or in combination with potassium iodide (KI). Cats diagnosed with sporotrichosis received orally ITZ (100 mg/cat/day) or combination therapy with ITZ (100 mg/cat/day) and KI (2.5-5 mg/kg/day) in the case of worsening or stagnation of the clinical condition. At each monthly visit, blood samples were collected at an interval of 4 h for analysis of trough and peak plasma ITZ concentrations by HPLC. Clinical features and laboratory parameters were evaluated during follow-up. Sixteen cats were included in the study. The median plasma ITZ concentration of all cats was 0.75 µg/mL. The median plasma ITZ concentration was 0.5 µg/mL in cats that received ITZ monotherapy (n = 12) and 1.0 µg/mL in those treated with ITZ + KI (n = 4). The clinical cure rate was 56.3% (n = 9) and the median treatment duration was 8 weeks. Nine cats (56.3%) developed adverse clinical reactions, and hyporexia was the most frequent (n = 8; 88.9%). Serum alanine aminotransferase was elevated in four cats (25%). The median plasma ITZ concentration detected in cats was considered to be therapeutic (>0.5 µg/mL) and was reached after 4 weeks of treatment. Plasma ITZ concentrations were higher in cats that received ITZ + KI compared to those treated only with ITZ, suggesting pharmacokinetic synergism between these drugs.

Although research on aspergillosis and mucormycosis confection is important to optimize antifungal therapy, data on this issue is scarce. Thus, we systematically investigated aspergillosis coinfection in patients with proven mucormycosis. Medical records of adult patients with proven mucormycosis whose formalin-fixed paraffin-embedded (FFPE) tissue sections were available, in a tertiary hospital from August 2007 to July 2023 were retrospectively reviewed to assess coinfection with aspergillosis. We noted cultures of fungi from sterile and non-sterile sites and performed polymerase chain reaction (PCR) assays on FFPE tissues to detect Aspergillus- and Mucorales-specific DNA. Sixty-seven patients with proven mucormycosis, including 12 (18%) with a positive culture of the mucormycosis agent from sterile site cultures, were enrolled. Fungal cultures from sterile and non-sterile sites revealed Aspergillus spp. growth in nine (13%) of the 67 patients, including two sterile and seven non-sterile cultures. The fungal PCR analysis from the FFPE sections was positive for Aspergillus-specific PCR in five (7%) and positive for both Aspergillus- and Mucorales-specific PCR results in eight (12%). Overall, 21 (31%) of the 67 patients with proven mucormycosis had microbiologic and/or molecular evidence of aspergillosis coinfection. Positive blood or bronchoalveolar lavage fluid galactomannan results were more common in the coinfection group (67% [14/21]) than in the mucormycosis group (37% [17/46], P = .024). No significant difference in mortality between the two groups was observed. Approximately one-third of patients with proven mucormycosis exhibited molecular and/or microbiologic evidence of aspergillosis coinfection. Further research is needed to identify patients with aspergillosis and mucormycosis coinfections, for optimal antifungal therapy.

We evaluated the diagnostic performance of the β-d-glucan (BDG) test (Beijing Gold Mountain River Tech) in diagnosing invasive fungal disease (IFD) and its variations among patients with different risks. Patients ≥18 years old who underwent a serum BDG test (positive cutoff value >80 pg/ml) from April 2017 through May 2018 were collected consecutively. Patients were classified into three groups: group 1, patients with host factors as defined by the prior 2008 European Organization for Research and Treatment (EORTC) criteria; group 2, those with extended host factors in 2020 EORTC criteria; and group 3, those without any risk factor mentioned in the criteria. IFD was defined by 2020 EORTC criteria, but BDG was not considered. Diagnostic performance of the serum BDG test was measured by the area under the curve (AUC) of the receiver-operating characteristic curve. Among 469 patients, 15.4% (72/469) were diagnosed with IFD (48/191 [25.1%], 14/144 [9.7%], and 10/134 [7.5%] in groups 1, 2, and 3, respectively). The BDG assay showed fair performance (AUC 0.748 [95% CI: 0.688-0.810]). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 77.8%, 60.7%, 26.4%, and 93.8%, respectively. PPV was higher in group 1, and NPV was higher in group 3. Additionally, diagnostic odds ratios were 6.73, 2.88, and 5.92 in groups 1, 2, and 3. Immunosuppressant use, non-IFD/Candida colonization, and central venous catheter were associated with false positivity. Clinicians should cautiously interpret the BDG assay, considering the various diagnostic performances depending on the different levels of risk.

Cryptococcus neoformans is a widely distributed opportunistic pathogenic fungus. While C. neoformans commonly infects immunocompromised individuals, it can also affect those who are immunocompetent. Transmission of C. neoformans primarily occurs through the respiratory tract, leading to the development of meningitis. The mortality rate of Cryptococcal meningitis is high, and treatment options are limited. Cryptococcus neoformans infections pose a significant public health threat and currently lack targeted and effective response strategies. This study aimed to screen T lymphocyte (cytotoxic T lymphocyte and helper T lymphocyte) and B lymphocyte epitopes derived from four C. neoformans antigens and develop two multi-epitope vaccines by combining them with various adjuvants. Molecular docking results demonstrated that the vaccines bind stably to Toll-like receptor 4 ( and induce innate immunity. The credibility of the molecular docking results was validated through subsequent molecular dynamics simulations. Furthermore, the results of immune simulation analyses underscored the multi-epitope vaccine's capability to effectively induce robust humoral and cellular immune responses within the host organism. These two vaccines have demonstrated theoretical efficacy against C. neoformans infection as indicated by computer analysis. Nevertheless, additional experimental validation is essential to substantiate the protective efficacy of the vaccines.

Talaromycosis marneffei (T.M) is the primary opportunistic infection of AIDS patients, and its morbidity and mortality are extremely high. To further clarify the disease characteristics of patients and provide a solid basis for in-depth exploration of their pathogenic mechanisms, we retrospectively summarized and analyzed their clinical data. We included all T.M patients tested for direct antiglobulin test (DAT) in the study. Interestingly, we found that AIDS-T.M patients had an extremely high rate of DAT positivity (92/127, 72.44%). In univariate analysis, a positive DAT was associated with blood culture of TM (P = .021), hypoproteinemia (P = .001), anemia (P = .001), thrombocytopenia (P = .003), sepsis (P = .007), and Sequential Organ Failure Assessment (SOFA) (P = .001). Hypoproteinemia, anemia, SOFA, APTT > 32.6 s, and AST > 40 U/l were studied by logistic regression. Logistic regression revealed that SOFA (OR = 1.311, P = .043), hypoproteinemia (OR = 0.308, P = .021), and anemia (OR = 0.19, P = .044) were associated with positive DAT. Positive DAT was associated with severe disease manifestations such as sepsis, and the DAT test is crucial in patients with fungemia.

The Trichophyton mentagrophytes complex comprises a group of dermatophyte fungi responsible for various dermatological infections. The increasing drug resistance of this species complex, especially terbinafine resistance of Trichophyton indotineae, is a major concern in dermatologist practice. This study provides a comprehensive analysis of T. mentagrophytes complex strains isolated from patients in Hue City, Vietnam, focusing on their phenotypic and genetic characteristics, antifungal susceptibility profiles, and molecular epidemiology. Keratinophilic fungi from dermatophytosis culture samples were identified morphologically and phenotypically, with species and genotypes confirmed by internal transcribed spacer sequencing and phylogenetic analysis. Antifungal susceptibility testing was carried out to evaluate their susceptibility to itraconazole, voriconazole, and terbinafine. The 24% (n = 27/114) of superficial mycoses were phenotypically attributed to T. mentagrophytes complex isolates. Trichophyton interdigitale, mainly genotype II*, was predominant (44.4%), followed by T. mentagrophytes genotype III* (22.2%), T. indotineae (14.8%), T. tonsurans (11.2%), and T. mentagrophytes (7.4%). While all isolates were susceptible to itraconazole and voriconazole, half of T. indotineae isolates exhibited resistance to terbinafine, linked to the Phe397Leu mutation in the SQLE protein. This study highlighted the presence of terbinafine-resistant T. indotineae isolates in Vietnam, emphasizing the need to investigate dermatophyte drug resistance and implement effective measures in clinical practice.