Medical mycology最新文献

The etiology of tinea capitis changes over time, mainly due to trend in migration. We report 19 cases of tinea capitis caused by Microsporum audouinii, an uncommon agent in South America, all of them confirmed by molecular methods. All patients were male. The average age was 6.1 years. 15 patients were residents of Rio de Janeiro city and 4 were from neighboring cities. Among the patients submitted to follow-up, griseofulvin was prescribed for 8 of them. Due to medication shortages, terbinafine was prescribed for 5 patients, needing to be switched in 3 cases, with a bigger total average time until clinical improvement. The study reaffirms the emergence of a new etiological agent in Rio de Janeiro, Brazil.

Invasive infections caused by non-albicans Candida are increasing worldwide. However, there is still a lack of information on invasive candidiasis (IC) in the pediatric setting, including susceptibility profiles and clonal studies. We investigated the clinical, epidemiologic, and laboratory characteristics of IC, possible changes in antifungal susceptibility profiles over time, and the occurrence of clonality in our tertiary children's hospital. We analyzed 123 non-duplicate Candida isolates from sterile sites of pediatric patients in a tertiary hospital in southern Brazil, between 2016 and 2021. Data on demographics, comorbidities, and clinical outcomes were collected. Candida species distribution, antifungal susceptibility profiles, biofilm production, and molecular epidemiology of isolates were assessed using reference methods. The range of IC incidence was 0.88-1.55 cases per 1000 hospitalized patients/year, and the IC-related mortality rate was 20.3%. Of the total IC cases, 42.3% were in patients aged < 13 months. Mechanical ventilation, parenteral nutrition, and intensive care unit (ICU) admission were common in this group. In addition, ICU admission was identified as a risk factor for IC-related mortality. The main site of Candida spp. isolation was blood, and non-albicans Candida species were predominant (70.8%). No significant clonal spread was observed among isolates of the three most commonly isolated species, and 99.1% of all isolates were biofilm producers. The incidence of IC and strain susceptibility patterns may vary over time, geographically, and among different populations. Non-albicans Candida species were predominant in this study. Notably, clonal expansion and emergence of antifungal drug resistance were not observed in our pediatric setting.

Azole resistance has emerged as a new therapeutic challenge in patients with aspergillosis. Various resistance mutations are attributed to the widespread use of triazole-based fungicides in agriculture. This study explored the prevalence of azole-resistant Aspergillus fumigatus (ARAF) and other aspergilli in the Argentine environment. A collection of A. fumigatus and other aspergilli strains isolated from soil of growing crops, compost, corn, different animal feedstuffs, soybean and chickpea seeds were screened for azole resistance. No ARAF was detected in any of the environmental samples studied. However, five A. flavus, one A. ostianus, one A. niger and one A. tamarii recovered from soybean and chickpea seeds showed reduced susceptibility to medical azole antifungals (MAA). The susceptibility profiles of five A. flavus isolates, showing reduced susceptibility to demethylase inhibitors (DMIs), were compared with those of 10 isolates that exhibited susceptibility to MAA. A. flavus isolates that showed reduced MAA susceptibility exhibited different susceptibility profile to DMIs. Prothioconazole and tebuconazole were the only DMIs significantly less active against isolates with reduced susceptibility to MAA. Although no ARAF isolates were found in the samples analysed, other aspergilli with reduced susceptibility profile to MAA being also important human pathogens causing allergic, chronic and invasive aspergillosis, are present in the environment in Argentina. Although a definitive link between triazole-based fungicide use and isolation of azole-resistant human pathogenic aspergilli from agricultural fields in Argentina remains elusive, this study unequivocally highlights the magnitude of the environmental spread of azole resistance among other Aspergillus species.

Lobomycosis, also called paracoccidioidomycosis ceti, is a chronic mycotic cutaneous disease affecting odontocetes. Lobomycosis-like disease (LLD) has a clinical presentation consistent with lobomycosis but lacks a histological and molecular diagnosis. We review the literature on lobomycosis aetiology, clinical signs and pathogenesis, species affected and geographic distribution and examine the factors influencing the presence, transmission and prevalence of the disease, to better understand its ecology. In addition, we provide unpublished information on LLD in two common bottlenose dolphin (Tursiops truncatus) communities inhabiting the Gulf of Guayaquil, Ecuador. Lobomycosis and LLD occur in Delphinidae from the Atlantic, Pacific, and Indian Oceans between 33°N and 35°S. Primary risk factors include habitat, sex, age, sociality, and pollution. In dolphins from the Americas and Japan, lobomycosis is caused by Paracoccidioides ceti, family Ajellomycetaceae. The disease is characterized by cutaneous granulomatous lesions that may occur anywhere on the body, grow to large size, and may ulcerate. Histologically, the lesions consist of acanthosis and histiocytic granulomas between the skin and subcutaneous tissues, with inflammatory changes that extend deep into the dermis. Multiple yeast cells with a double refringent layer stained positive using Gomori-Grocott methenamine silver in the dermis of a T. truncatus from Ecuador diagnosed with LLD since 2011, a first record for the Southeast Pacific. Injuries may enable the entry of P. ceti into the dermis while skin contact likely favours transmission, putting males at higher risk than females. Lobomycosis and LLD may have a negative impact on small communities already threatened by anthropogenic factors.

Several false positive low serum cryptococcal antigen (SCrAg) reports by lateral flow assay (LFA) were identified in late 2016 at our tertiary care hospital. After the recall and correction of the problem in the reagent, we studied the significance of SCrAg LFA ≤ 1:10 from January 2017 to October 2023. Of 20 patients with 31 samples of SCrAg LFA ≤ 1:10, 14 patients (70%) were classified as true positives, four (20%) were indeterminate, and only two (10%) patients were false positives. If a new SCrAg LFA ≤ 1:10 is detected, it should be repeated, and additional workup should be pursued.

Candida auris is a pathogen of growing public health concern worldwide. However, risk factors contributing to C. auris infection in patients colonized with C. auris remain unclear. Understanding these risk factors is crucial to prevent colonization-to-infection transition and devise effective preventive strategies. This study aimed to investigate risk factors associated with C. auris infection compared to colonization. The study included 97 patients who acquired laboratory-confirmed C. auris in either matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry or VITEK 2 system from October 2019 to June 2023. Baseline demographics and known risk factors associated with C. auris infection were collected from electronic medical records. The infection group had C. auris from a sterile site or non-sterile site with evidence of infection. The colonization group was followed up for a median of 30 days for any signs of infection. Associations between relevant variables and C. auris infection were assessed using multivariable logistic regression. The infection group (n = 31) was more likely to be bedbound, with longer hospital stays and more arterial catheters. Chronic kidney disease (odds ratio [OR] 45.070), carriage of multidrug-resistant organisms (OR 64.612), and vasopressor use for > 20 days (OR 68.994) were associated with C. auris infection, after adjusting for sex, age, and prior colonization with C. auris. Chronic kidney disease, carriage of multidrug-resistant organisms, and prolonged vasopressor use emerged as significant risk factors for C. auris infection compared to colonization. They could be used to predict C. auris infection early in patients colonized with C. auris.

The skin of patients with atopic dermatitis (AD) has a greater diversity of mycobiota. An observational, prospective, cross-sectional, analytical, and comparative study was conducted involving 80 patients with AD Group (ADG) and 50 individuals without AD (wADG) in a tertiary hospital in Brazil. Skin scale samples were collected from the frontal, cervical, fossae cubital, and popliteal regions and identified using molecular biology techniques. The results showed that 47.5% of ADG had identified yeasts compared to 0% of wADG (P < .001). The yeasts Rhodotorula mucilaginosa and Candida parapsilosis were the most abundant. The probability of colonization increased with age, showing values of 40% at 60 months and 80% at 220 months (P = .09). The cervical region (12.5%) was colonized to the greatest extent. Our findings revealed that positive mycology was not more probable when the scoring of atopic dermatitis or eczema area and severity index value increased (P = .23 and .53, respectively). The results showed that the sex, age, and different population types directly affected the composition of the mycobiota in the population analyzed. A higher frequency of colonization and greater diversity of yeast species were detected in the cutaneous mycobiota of children with AD.

Global epidemiological data show that the incidence of invasive fungal disease (IFD) has increased in recent decades, with the rising frequency of infections caused by Aspergillus and Mucorales order species. The number and variety of patients at risk of IFD has also expanded, owing in part to advances in the treatment of hematologic malignancies and other serious diseases, including hematopoietic stem cell transplantation (HCT) and other therapies causing immune suppression. Isavuconazonium sulfate (active moiety: isavuconazole) is an advanced-generation triazole antifungal approved for the treatment of invasive aspergillosis and mucormycosis that has demonstrated activity against a variety of yeasts, moulds, and dimorphic fungi. While real-world clinical experience with isavuconazole is sparse in some geographic regions, it has been shown to be effective and well tolerated in diverse patient populations, including those with multiple comorbidities who may have failed to respond to prior triazole antifungal therapy. Isavuconazole may be suitable for patients with IFD receiving concurrent QTc-prolonging therapy, as well as those on venetoclax or ruxolitinib. Data from clinical trials are not available to support the use of isavuconazole prophylactically for the prevention of IFD or for the treatment of endemic IFD, such as those caused by Histoplasma spp., but real-world evidence from case studies suggests that it has clinical utility in these settings. Isavuconazole is an option for patients at risk of IFD, particularly when the use of alternative antifungal therapies is not possible because of toxicities, pharmacokinetics, or drug interactions.