Search Results (74)

The cochineal insect Dactylopius coccus Costa (Hemiptera) has cultural and economic value because it produces carminic acid that is used commercially. In this study, distinct fungi were cultured from dissected tissue and identified as Penicillium, Coniochaeta, Arthrinium, Cladosporium, Microascus, Aspergillus, and Periconia. Fungi were microscopically observed inside cochineals in the gut, fat body, and ovaries. Since cochineals spend their lives attached to cactus leaves and use the sap as feed, they can obtain fungi from cacti plants. Indeed, we obtained Penicillium, Aspergillus, and Cladosporium fungi from cacti that were identical to those inside cochineals, supporting their plant origin. Fungi could be responsible for the degrading activities in the insect guts, since cellulase, pectinase, and amylase enzymatic activities in insect guts decreased in fungicide-treated cochineals. Our findings set the basis for the further study of the interactions between insects, fungi, and their host plants. Full article

Human endemic mycoses are potentially fatal diseases caused by a diverse group of fungi that can alter their morphology in response to an increase in temperature. These thermally dimorphic fungi affect both healthy and immunocompromised hosts, causing a substantial health and economic burden. Despite this, the diagnosis of endemic mycoses is still a formidable challenge for several reasons, including similar symptomatology, limited utility of classical diagnostic methods, inaccessibility to reliable molecular approaches in most endemic areas, and a lack of clinical suspicion out of these regions. This review summarizes essential knowledge on thermally dimorphic fungi and the life-threatening diseases they cause. The principle, advantages and limitations of the methods traditionally used for their diagnosis are also described, along with the application status and future directions for the development of alternative diagnostic strategies, which could help to reduce the disease burden in endemic areas. Full article

Epiphytic yeasts represent an important source for the development of novel strategies aiming to combat food microbial contamination. The present study deals with the characterization of nine yeast strains belonging to Starmerella, Candida, Metschinikowia, Lachancea, Kodamaea and Pichia genera, isolated from the surface of plants from the Botanical Garden “Dimitrie Brandza” (Bucharest, Romania) for use as antimicrobial and probiotic agents. The tests involved the determination of the safe status, cell growth under stress conditions, and activity against pathogenic Candida and bacteria strains, respectively, as well as phytopathogenic filamentous fungi and lipolytic activity. None of the nine strains showed all the characteristics for virulence and pathogenicity, with the rare positive results being explained rather by their adaptability to the habitats of origin. The strains Lachancea thermotolerans CMGB-ST12 and Kodamaea ohmeri CMGB-ST19 grew at 37 °C; Metschnikowia reukaufii CMGB-ST21.2, M. reukaufii CMGB-ST.8.1 and M. reukaufii CMGB ST10 grew in the presence of 10% NaCl, while L. thermotolerans CMGB-ST12 and K. ohmeri CMGB-ST19 tolerated both acidic and alkaline pH values well (3.0 to 12.0). The studied yeast strains showed good antimicrobial activity against Candida krusei, Candida albicans and Gram-negative bacterial strains, with K. ohmeri CMGB-ST19 and Pichia membranaefaciens CMGB-ST53 inhibiting up to 100% the development of filamentous fungi. All the strains produced lipases for tributyrin hydrolysis, the best producer being Starmerella bombi CMGB-ST1, and only Candida magnoliae CMGB-ST8.2 tested positive against other probiotic yeasts. Overall, our nine yeast strains show high potential for industrial applications, for obtaining probiotic products and for preventing the development of a wide range of microbial food contaminants. Full article

Mushroom Jin Er has attracted widespread attention in Asia over the past two decades due to its medicinal properties and nutritional values. In the present study, Jin Er basidiocarps were often found to be surrounded by Stereum hirsutum fruiting bodies in their natural habitat and occasionally in artificial cultivation. The observation of two different kinds of mycelia within the hymenium and analyses of ITS sequences confirmed that Jin Er basidiocarps were composed of two fungal species, Naematelia aurantialba and S. hirsutum. This heterogeneity of Jin Er fruiting bodies is indeed distinct from the homogeneous hypha of Tremella fuciformis found in Yin Er mushroom, although its development also requires the presence of another fungus Annulohypoxylon stygium. Basidiospores can germinate on the surface of basidiocarps and produce mycelia. However, basidiospores in PDA medium can only bud into yeast-like conidia. The yeast-like conidia of N. aurantialba can transform into pseudohyphae with a change in temperature from 20 °C to 28 °C or switch into filamentous cells on an induction medium (IDM) at 20 °C, 25 °C and 28 °C. This dimorphic was reported for the first time in N. aurantialba. Haustorium-like structures were abundantly observed both within the hymenium and in the aerial mycelia cultured on the IDM. The developmental process was documented firstly in this study, involving the formation of protuberances with basal clamp connections, elongation at the protuberances, branch production, and eventual maturation. However, further observation is required to determine whether the haustorium-like structures can penetrate S. hirsutum hyphae. These findings are expected to provide valuable insights into the relationship and interaction between these two fungi, thereby advancing the cultivation of fruiting bodies. Full article

The incidence and distribution of coccidioidomycosis are increasing. Information scarcity is evident in Mexico, particularly in non-endemic zones and specific populations. We compared the treatment and outcomes for patients with isolated pulmonary infections and those with disseminated coccidioidomycosis, including mortality rates within six weeks of diagnosis. Of 31 CM cases, 71% were male and 55% were disseminated. For 42% of patients, there was no evidence of having lived in or visited an endemic region. All patients had at least one comorbidity, and 58% had pharmacologic immunosuppressants. The general mortality rate was 30%; without differences between disseminated and localized disease. In our research, we describe a CM with a high frequency of disseminated disease without specific risk factors and non-significant mortality. Exposure to endemic regions was not found in a considerable number of subjects. We consider diverse reasons for why this may be, such as climate change or migration. Full article

Histoplasmosis is a global infection caused by the thermally dimorphic fungus, Histoplasma capsulatum complex. It is endemic in the United States, as well as in Central and South America. In Taiwan, histoplasmosis is rare, with the first reported case not occurring until 1977. We summarized a total of 17 cases reported in Taiwan over the past 40 years and provided detailed descriptions for four probable indigenous cases. Due to the lack of rapid diagnostic tools and clinical suspicion, histoplasmosis may be underdiagnosed in Taiwan. We recognize that a limitation of our review is the lack of data on the environmental surveillance for H. capsulatum complex in Taiwan. Conducting a further phylogenetic analysis on both environmental and clinical isolates would provide valuable evidence for the region. Full article

Invasive fungal infections have recently been recognized by the WHO as a major health, epidemiological, and economic issue. Their high mortality rates and the emergence of drug resistance have driven the development of new molecules, including olorofim, an antifungal belonging to a new family of compounds, the orotomides. A review was conducted on the PubMed database and the ClinicalTrials.gov website to summarize the microbiological profile of olorofim and its role in the treatment of filamentous fungal infections. Twenty-four articles were included from the search and divided into two groups: an “in vitro” group focusing on minimum inhibitory concentration (MIC) results for various fungi and an “in vivo” group evaluating the pharmacokinetics (PK), pharmacodynamics (PD), efficacy, and tolerability of olorofim in animal models of fungal infection and in humans. Olorofim demonstrated in vitro and in vivo activity against numerous filamentous fungi, including azole-resistant Aspergillus fumigatus, various dermatophytes, and endemic and dimorphic fungi. in vitro results showed higher MICs for certain Fusarium species and dematiaceous fungi Alternaria alternata and Exophiala dermatitidis; further in vivo studies are needed. Published PK-PD data in humans are limited. The results of the ongoing phase III clinical trial are eagerly awaited to evaluate olorofim’s clinical impact. Full article

Fusarium sacchari, a key pathogen of sugarcane, is responsible for the Pokkah boeng disease (PBD) in China. The 14-3-3 proteins have been implicated in critical developmental processes, including dimorphic transition, signal transduction, and carbon metabolism in various phytopathogenic fungi. However, their roles are poorly understood in F. sacchari. This study focused on the characterization of two 14-3-3 protein-encoding genes, FsBmh1 and FsBmh2, within F. sacchari. Both genes were found to be expressed during the vegetative growth stage, yet FsBmh1 was repressed at the sporulation stage in vitro. To elucidate the functions of these genes, the deletion mutants ΔFsBmh1 and ΔFsBmh2 were generated. The ΔFsBmh2 exhibited more pronounced phenotypic defects, such as impaired hyphal branching, septation, conidiation, spore germination, and colony growth, compared to the ΔFsBmh1. Notably, both knockout mutants showed a reduction in virulence, with transcriptome analysis revealing changes associated with the observed phenotypes. To further investigate the functional interplay between FsBmh1 and FsBmh2, we constructed and analyzed mutants with combined deletion and silencing (ΔFsBmh/siFsBmh) as well as overexpression (O-FsBmh). The combinations of ΔFsBmh1/siFsBmh2 or ΔFsBmh2/siFsBmh1 displayed more severe phenotypes than those with single allele deletions, suggesting a functional redundancy between the two 14-3-3 proteins. Yeast two-hybrid (Y2H) assays identified 20 proteins with pivotal roles in primary metabolism or diverse biological functions, 12 of which interacted with both FsBmh1 and FsBmh2. Three proteins were specifically associated with FsBmh1, while five interacted exclusively with FsBmh2. In summary, this research provides novel insights into the roles of FsBmh1 and FsBmh2 in F. sacchari and highlights potential targets for PBD management through the modulation of FsBmh functions. Full article

Cetaceans, which are integral to marine ecosystems, face escalating anthropogenic threats, including climate change and pollution, positioning them as critical sentinel species for ocean and human health. This review explores the neglected realm of non-Candida yeasts in cetaceans, addressing the gaps in the understanding of their prevalence, pathogenicity, and environmental impacts. By examining identified species such as Cryptococcus spp., Paracoccidioides spp., and several dimorphic fungi, this review emphasizes global prevalence, epidemiology and ecology, pathogenicity, and potential zoonotic implications. It also discusses the fine line between yeast commensalism and pathogenicity by considering environmental influences such as pollution, climate shifts, and immune suppression. Environmental impact discussions delve into how rising ocean temperatures and pollution can modify yeast mycobiota, potentially affecting marine host health and broader ecosystem dynamics. The cetacean’s unique physiology and ecological niches are considered, highlighting potential impacts on behaviors, reproductive success, and survival rates. Identifying crucial knowledge gaps, the review calls for intensified research efforts, employing advanced molecular techniques to unravel the cetacean mycobiome. Systematic studies on yeast diversity, antifungal susceptibility, and their influence on environmental and ecosystem health are proposed, and the balance between commensal and pathogenic species emphasizes the significance of the One Health approach. In conclusion, as marine mammals face unprecedented challenges, unveiling non-Candida yeasts in cetaceans emerges as a critical endeavor with far-reaching implications for the conservation of marine ecosystems and for both animal and human public health. Full article

Beauveria bassiana is a dimorphic and entomopathogenic fungus with different ecological roles in nature. In pathogenic fungi, yeast-to-mycelial conversion, which is controlled by environmental factors, is required for virulence. Here, we studied the effects of different stimuli on the morphology of two B. bassiana strains and compared the toxicities of culture filtrates. In addition, we explored the role of volatiles as quorum sensing-like signals during dimorphic transition. The killing assays in Caenorhabditis elegans (Nematoda: Rhabditidae) showed that strain AI2 isolated from a mycosed insect cadaver had higher toxicity than strain AS5 isolated from soil. Furthermore, AI2 showed earlier yeast-to-mycelial switching than AS5. However, an increase in inoculum size induced faster yeast-to-mycelium conversion in AS5 cells, suggesting a cell-density-dependent phenomenon. Gas chromatography-mass spectrometry (GC-MS) analyses showed that the fingerprint of the volatiles was strain-specific; however, during the morphological switching, an inverse relationship between the abundance of total terpenes and 3-methylbutanol was observed in both strains. Fungal exposure to 3-methylbutanol retarded the yeast-to-mycelium transition. Hence, this study provides evidence that volatile compounds are associated with critical events in the life cycle of B. bassiana. Full article

Emergomycosis is an endemic mycosis caused by the Emergomyces species. Infections due to this agent have been reported globally. Hence, the present systematic review on Emergomyces infections was conducted to study the disease epidemiology, underlying diseases and risk factors, causative agents, and treatment and outcome. The MEDLINE, Scopus, Embase, and Web of Science databases were searched systematically with appropriate keywords from January 1990 to October 2022. A total of 77 cases of emergomycosis were included in the analysis. Emergomycosis was most commonly seen in patients with human immunodeficiency virus (HIV) infection (n = 61, 79.2%) and HIV-uninfected patients with or without other comorbidities (n = 16, 20.8%). The underlying disease and risk factors significantly associated with emergomycosis in the HIV-infected patients were CD4+ T-cell counts less than 100 cells/mm³ (n = 55, 90.2%), anaemia (n = 30, 49.2%), and thrombocytopenia (n = 17, 27.9%), whereas in the HIV-uninfected patients, treatment with immunosuppressive drugs (n = 10, 62.5%), renal disease (n = 8, 50%), transplant recipients (n = 6, 37.5%), and diabetes mellitus (n = 4, 25%) were the significant risk factors associated with emergomycosis. Emergomyces africanus (n = 55, 71.4%) is the most common causative agent, followed by E. pasteurianus (n = 9, 11.7%) and E. canadensis (n = 5, 6.5%). E. africanus was most often isolated from HIV-infected patients (n = 54, 98.2%), whereas E. pasteurianus was most common in HIV-uninfected patients (n = 5, 55.6%). The all-cause mortality rate of the total cohort is 42.9%. No significant variation in the mortality rate is observed between the HIV-infected patients (n = 28, 36.4%) and the HIV-uninfected patients (n = 5, 6.5%). In conclusion, with an increase in the immunosuppressed population across the globe in addition to HIV infection, the case burden of emergomycosis may increase in the future. Hence, clinicians and mycologists should be vigilant and clinically suspicious of emergomycosis, which helps in early diagnosis and initiation of antifungal treatment to prevent disease mortality. Full article

Histoplasmosis is a globally distributed systemic infection caused by the dimorphic fungus Histoplasma capsulatum (H. capsulatum). This fungus can cause a wide spectrum of clinical manifestations, and the diagnosis of progressive disseminated histoplasmosis is often a challenge for clinicians. Although microscopy and culture remain the gold standard diagnostic tests for Histoplasma identification, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) has emerged as a method of microbial identification suitable for the confirmation of dimorphic fungi. However, to our knowledge, there are no entries for H. capsulatum spectra in most commercial databases. In this review, we describe the case of disseminated histoplasmosis in a patient living with HIV admitted to our university hospital that we failed to identify by the MALDI-TOF method due to the limited reference spectrum of the instrument database. Furthermore, we highlight the utility of molecular approaches, such as conventional polymerase chain reaction (PCR) and DNA sequencing, as alternative confirmatory tests to MALDI-TOF technology for identifying H. capsulatum from positive cultures. An overview of current evidence and limitations of MALDI-TOF-based characterization of H. capsulatum is also presented. Full article

Proteomics provide a robust approach to profile and quantify proteins within cells, organs, or tissues, providing comprehensive insights about the dynamics of cellular processes, modifications, and interactions. Similarly, understanding the transcriptome is essential to decipher functional elements of the genome, unraveling the mechanisms of disease development and the molecular constituents of cells and tissues. Some thermodimorphic fungi of the genus Sporothrix cause sporotrichosis, a subcutaneous mycosis of worldwide relevance. The transcriptome and proteome of the main Sporothrix species of clinical interest can elucidate the mechanisms underlying pathogenesis and host interactions. Studies of these techniques can contribute to the advancement of novel diagnostic and therapeutic strategies. A literature review was carried out, addressing all articles based on proteomics using mass spectrometry and transcriptomics of Sporothrix spp. Twenty-one studies were eligible for this review. The main findings include proteins and genes involved in dimorphism, cell differentiation, thermotolerance, virulence, immune evasion, metabolism, cell adhesion, cell transport, and biosynthesis. With the spread and emergence of sporotrichosis in different countries, ongoing research efforts and new discoveries are welcome to advance knowledge about this mycosis and its agents. Full article

Coccidioides species are thermally dimorphic fungi found in geographically defined areas of the Western Hemisphere. The primary portal of entry is respiratory, with symptomatic pneumonic diseases as the most common presentation. Subsequent pulmonary complications as well as extrapulmonary metastatic infection may occur, either of which may be the presenting disease manifestation. Cavitary lung disease may be found incidentally or when investigating symptoms such as cough or hemoptysis. This study aims to explore the spectrum of coccidioidal cavities and the evaluation and management in a cohort of patients seen at Kern Medical over the last 12 years. Full article

Background: Sporotrichosis is a fungal infection that can affect both humans and animals, caused by a species of thermo-dimorphic fungi of the genus Sporothrix. This pathology can be acquired by subcutaneous traumatic inoculation through contact with contaminated plants, soil or decomposing organic matter, and/or by inhalation of conidia. The infection can progress to chronic skin infection, or it can even spread to blood vessels, lymph, muscles, bones, and other organs, such as the lungs and nervous system. Those disseminated types are usually associated with cellular immunodeficiency and infection by inhalation, which explains why people living with human immunodeficiency virus (PLHIV) get infected in such a manner. This virus changes the natural history of sporotrichosis, producing a greater fungal load. Methods: The search was carried out in three databases: Pubmed, Scopus, and Scielo. Eligible articles were considered as those that described sporotrichosis in patients infected with HIV-AIDS, as well as case series. Results: A total of 24 articles were selected, with a sum of 37 patients with sporotrichosis and HIV infection. Of these patients, 31 came from Brazil, two from the United States, one from South Africa, one from Bangladesh, and two from an unspecified region. Regarding epidemiology, a predominance of the male sex was found in 28 of the 37 cases (75.6%), while nine were female (24.3%). Conclusions: Sporotrichosis infection continues to present in a more severe and disseminated way among HIV-positive subjects with lower CD4⁺ counts. Full article