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Virulence Dec 2023Pulmonary infections caused by the mould pathogen are a major cause of morbidity and mortality globally. Compromised lung defences arising from immunosuppression,... (Review)
Review
Pulmonary infections caused by the mould pathogen are a major cause of morbidity and mortality globally. Compromised lung defences arising from immunosuppression, chronic respiratory conditions or more recently, concomitant viral or bacterial pulmonary infections are recognised risks factors for the development of pulmonary aspergillosis. In this review, we will summarise our current knowledge of the mechanistic basis of pulmonary aspergillosis with a focus on emerging at-risk populations.
Topics: Humans; Aspergillus fumigatus; Virulence; Aspergillosis; Virulence Factors; Pulmonary Aspergillosis
PubMed: 36752587
DOI: 10.1080/21505594.2023.2172264 -
Ugeskrift For Laeger Feb 2024External otitis (EO) is a common and often painful infection in the ear canal. This review provides an overview of the typical presentation, causes, complications, and... (Review)
Review
External otitis (EO) is a common and often painful infection in the ear canal. This review provides an overview of the typical presentation, causes, complications, and treatment of EO. The condition is influenced by factors like pH levels, inflammation, and bacterial or fungal invasion. Most common bacteria involved are Pseudomonas aeruginosa and Staphylococcus aureus, and most common fungi are Aspergillus and Candida species. EO can lead to serious complications, such as necrotising EO, which requires prompt medical attention. Treatment involves local care, ear drops, and, in severe cases, systemic antibiotics.
Topics: Humans; Otitis Externa; Inflammation; Anti-Bacterial Agents; Candida; Staphylococcal Infections
PubMed: 38445328
DOI: 10.61409/V05230339 -
Seminars in Respiratory and Critical... Feb 2024The filamentous fungus causes a wide spectrum of diseases in the human lung, with being the most pathogenic and allergenic subspecies. The broad range of clinical... (Review)
Review
The filamentous fungus causes a wide spectrum of diseases in the human lung, with being the most pathogenic and allergenic subspecies. The broad range of clinical syndromes that can develop from the presence of in the respiratory tract is determined by the interaction between host and pathogen. In this review, an oversight of the different clinical entities of pulmonary aspergillosis is given, categorized by their main pathophysiological mechanisms. The underlying immune processes are discussed, and the main clinical, radiological, biochemical, microbiological, and histopathological findings are summarized.
Topics: Humans; Lung; Aspergillus; Pulmonary Aspergillosis; Aspergillus fumigatus
PubMed: 38286136
DOI: 10.1055/s-0043-1777259 -
Immunity Aug 2023Invasive fungal infections are associated with high mortality rates, and the lack of efficient treatment options emphasizes an urgency to identify underlying disease...
Invasive fungal infections are associated with high mortality rates, and the lack of efficient treatment options emphasizes an urgency to identify underlying disease mechanisms. We report that disseminated Candida albicans infection is facilitated by interleukin-1 receptor antagonist (IL-1Ra) secreted from macrophages in two temporally and spatially distinct waves. Splenic CD169 macrophages release IL-1Ra into the bloodstream, impeding early neutrophil recruitment. IL-1Ra secreted by monocyte-derived tissue macrophages further impairs pathogen containment. Therapeutic IL-1Ra neutralization restored the functional competence of neutrophils, corrected maladapted hyper-inflammation, and eradicated the otherwise lethal infection. Conversely, augmentation of macrophage-secreted IL-1Ra by type I interferon severely aggravated disease mortality. Our study uncovers how a fundamental immunoregulatory mechanism mediates the high disease susceptibility to invasive candidiasis. Furthermore, interferon-stimulated IL-1Ra secretion may exacerbate fungal dissemination in human patients with secondary candidemia. Macrophage-secreted IL-1Ra should be considered as an additional biomarker and potential therapeutic target in severe systemic candidiasis.
Topics: Humans; Interleukin 1 Receptor Antagonist Protein; Candida albicans; Macrophages; Receptors, Interleukin-1; Sepsis
PubMed: 37478856
DOI: 10.1016/j.immuni.2023.06.023 -
PLoS Pathogens Aug 2023Fungal infections are rising, with over 1.5 billion cases and more than 1 million deaths recorded each year. Among these, Candida infections are frequent in at-risk...
Fungal infections are rising, with over 1.5 billion cases and more than 1 million deaths recorded each year. Among these, Candida infections are frequent in at-risk populations and the rapid development of drug resistance and tolerance contributes to their clinical persistence. Few antifungal drugs are available, and their efficacy is declining due to the environmental overuse and the expansion of multidrug-resistant species. One way to prolong their utility is by applying them in combination therapy. Here, we highlight recently described azole potentiators belonging to different categories: natural, repurposed, or novel compounds. We showcase examples of molecules and discuss their identified or proposed mode of action. We also emphasise the challenges in azole potentiator development, compounded by the lack of animal testing, the overreliance on Candida albicans and Candida auris, as well as the limited understanding of compound efficacy.
Topics: Animals; Candida; Candida albicans; Candidiasis; Antifungal Agents; Azoles
PubMed: 37651385
DOI: 10.1371/journal.ppat.1011583 -
Mycopathologia Oct 2023Aspergillus fumigatus is one the most ubiquitous airborne opportunistic human fungal pathogens. Understanding its interaction with host immune system, composed of... (Review)
Review
Aspergillus fumigatus is one the most ubiquitous airborne opportunistic human fungal pathogens. Understanding its interaction with host immune system, composed of cellular and humoral arm, is essential to explain the pathobiology of aspergillosis disease spectrum. While cellular immunity has been well studied, humoral immunity has been poorly acknowledge, although it plays a crucial role in bridging the fungus and immune cells. In this review, we have summarized available data on major players of humoral immunity against A. fumigatus and discussed how they may help to identify at-risk individuals, be used as diagnostic tools or promote alternative therapeutic strategies. Remaining challenges are highlighted and leads are given to guide future research to better grasp the complexity of humoral immune interaction with A. fumigatus.
Topics: Humans; Aspergillus fumigatus; Immunity, Humoral; Aspergillosis
PubMed: 37289362
DOI: 10.1007/s11046-023-00742-0 -
PLoS Pathogens Dec 2023Candida auris recently emerged as an urgent public health threat, causing outbreaks of invasive infections in healthcare settings throughout the world. This fungal... (Review)
Review
Candida auris recently emerged as an urgent public health threat, causing outbreaks of invasive infections in healthcare settings throughout the world. This fungal pathogen persists on the skin of patients and on abiotic surfaces despite antiseptic and decolonization attempts. The heightened capacity for skin colonization and environmental persistence promotes rapid nosocomial spread. Following skin colonization, C. auris can gain entrance to the bloodstream and deeper tissues, often through a wound or an inserted medical device, such as a catheter. C. auris possesses a variety of virulence traits, including the capacity for biofilm formation, production of adhesins and proteases, and evasion of innate immune responses. In this review, we highlight the interactions of C. auris with the host, emphasizing the intersection of laboratory studies and clinical observations.
Topics: Humans; Candida; Candidiasis; Virulence; Candida auris; Disease Outbreaks; Antifungal Agents
PubMed: 38127686
DOI: 10.1371/journal.ppat.1011843 -
Infection and Immunity Sep 2023Fungal infections represent a major, albeit neglected, public health threat with serious medical and economic burdens globally. With unacceptably high mortality rates,... (Review)
Review
Fungal infections represent a major, albeit neglected, public health threat with serious medical and economic burdens globally. With unacceptably high mortality rates, invasive fungal pathogens are responsible for millions of deaths each year, with a steadily increasing incidence primarily in immunocompromised individuals. The poor therapeutic options and rise of antifungal drug resistance pose further challenges in controlling these infections. These fungal pathogens have adapted to survive within mammalian hosts and can establish intracellular niches to promote survival within host immune cells. To do that, they have developed diverse methods to circumvent the innate immune system attack. This includes strategies such as altering their morphology, counteracting macrophage antimicrobial action, and metabolic adaptation. This is reminiscent of how bacterial pathogens have adapted to survive within host cells and cause disease. However, relative to the great deal of information available concerning intracellular bacterial pathogenesis, less is known about the mechanisms fungal pathogens employ. Therefore, here we review our current knowledge and recent advances in our understanding of how fungi can evade and persist within host immune cells. This review will focus on the major fungal pathogens, including , and , among others. As we discover and understand the strategies used by these fungi, similarities with their bacterial counterparts are becoming apparent, hence we can use the abundant information from bacteria to guide our studies in fungi. By understanding these strategies, new lines of research will open that can improve the treatments of these devastating fungal diseases.
Topics: Animals; Humans; Mycoses; Candida albicans; Aspergillus fumigatus; Cryptococcosis; Cryptococcus neoformans; Mammals
PubMed: 37506189
DOI: 10.1128/iai.00434-22 -
Plant Signaling & Behavior Dec 2023Root rot is one of the main diseases affecting Aconitum carmichaelii Debx. during cultivation, seriously limiting yields of this herb. Currently, there is no effective...
Root rot is one of the main diseases affecting Aconitum carmichaelii Debx. during cultivation, seriously limiting yields of this herb. Currently, there is no effective control measure for aconite root rot. The antifungal activities of antagonistic strains against aconite root rot pathogens (Fusarium proliferatum, Fusarium solani, and Fusarium oxysporum) were investigated in this study. Three antagonistic strains, JKT7, JKT28 and JKT39, were screened and identified as Trichoderma asperellum, Trichoderma hamatum and Trichoderma virens, respectively. Dual culture tests showed that the inhibition rates of the three Trichoderma strains on the pathogens were all approximately 70%. The volatile metabolites had inhibitory effects on the mycelial growth of pathogens, while the nonvolatile metabolites in the culture filtrates did not show significant inhibitory effects. The volatile components analyzed by GC‒MS were mainly ketones, esters, and alcohols. These results indicate that these strains of Trichoderma and their secondary metabolites have antimicrobial activities against the pathogens of aconite root rot. This study could provide a scientific basis for the biocontrol of aconite root rot.
Topics: Antifungal Agents; Aconitum; Fusarium; Trichoderma; Plant Diseases
PubMed: 37183693
DOI: 10.1080/15592324.2023.2211852 -
Microbiology Spectrum Jun 2023Candida auris, a multidrug-resistant human fungal pathogen that causes outbreaks of invasive infections, emerged as four distinct geographical clades. Previous studies... (Review)
Review
Candida auris, a multidrug-resistant human fungal pathogen that causes outbreaks of invasive infections, emerged as four distinct geographical clades. Previous studies identified genomic and proteomic differences in nutrient utilization on comparison to Candida albicans, suggesting that certain metabolic features may contribute to C. auris emergence. Since no high-throughput clade-specific metabolic characterization has been described yet, we performed a phenotypic screening of C. auris strains from all 4 clades on 664 nutrients, 120 chemicals, and 24 stressors. We identified common and clade- or strain-specific responses, including the preferred utilization of various dipeptides as nitrogen source and the inability of the clade II isolate AR 0381 to withstand chemical stress. Further analysis of the metabolic properties of C. auris isolates showed robust growth on intermediates of the tricarboxylic acid cycle, such as citrate and succinic and malic acids. However, there was reduced or no growth on pyruvate, lactic acid, or acetate, likely due to the lack of the monocarboxylic acid transporter Jen1, which is conserved in most pathogenic species. Comparison of C. auris and C. albicans transcriptomes of cells grown on alternative carbon sources and dipeptides as a nitrogen source revealed common as well as species-unique responses. C. auris induced a significant number of genes with no ortholog in C. albicans, e.g., genes similar to the nicotinic acid transporter (alternative carbon sources) and to the oligopeptide transporter () family (dipeptides). Thus, C. auris possesses unique metabolic features which could have contributed to its emergence as a pathogen. Four main clades of the emerging, multidrug-resistant human pathogen Candida auris have been identified, and they differ in their susceptibilities to antifungals and disinfectants. Moreover, clade- and strain-specific metabolic differences have been identified, but a comprehensive overview of nutritional characteristics and resistance to various stressors is missing. Here, we performed high-throughput phenotypic characterization of C. auris on various nutrients, stressors, and chemicals and obtained transcriptomes of cells grown on selected nutrients. The generated data sets identified multiple clade- and strain-specific phenotypes and induction of C. auris-specific metabolic genes, showing unique metabolic properties. The presented work provides a large amount of information for further investigations that could explain the role of metabolism in emergence and pathogenicity of this multidrug-resistant fungus.
Topics: Humans; Candidiasis; Candida auris; Proteomics; Candida; Candida albicans; Antifungal Agents; Dipeptides; Microbial Sensitivity Tests
PubMed: 37097196
DOI: 10.1128/spectrum.00498-23