scholarly journals Modulation of the Fungal-Host Interaction by the Intra-Species Diversity of C. albicans

Pathogens ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 11 ◽  
Author(s):  
◽  
Keyword(s):  
Fungal Pathogen ◽  
Fungal Species ◽  
Protective Mechanisms ◽  
Fungal Host ◽  
Host Interaction ◽  
Immunosuppressed Patients ◽  
Natural Diversity ◽  
Opportunistic Fungal Pathogen ◽  
Fungal Interactions ◽  
Human Infections

The incidence of human infections caused by the opportunistic fungal pathogen Candida albicans is on the rise due to increasing numbers of immunosuppressed patients. The importance of the immune system in preventing overgrowth of the colonizing fungus and thereby limiting infection is well recognized and host protective mechanisms widely investigated. Only recently, it was recognized that the natural diversity in the fungal species could also influence the outcome of the interaction between the fungus and the host. C. albicans strain-specific differences are complex and their regulation at the genomic, genetic, and epigenetic level and by environmental factors is only partially understood. In this review, we provide an overview of the natural diversity of C. albicans and discuss how it impacts host-fungal interactions and thereby affects the balance between commensalism versus disease.

scholarly journals Troponoids Can Inhibit Growth of the Human Fungal Pathogen Cryptococcus neoformans

2017 ◽  
Vol 61 (4) ◽  
Author(s):  
Maureen J. Donlin ◽  
Anthony Zunica ◽  
Ashlyn Lipnicky ◽  
Aswin K. Garimallaprabhakaran ◽  
Alex J. Berkowitz ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Fungal Pathogen ◽  
Antimicrobial Activities ◽  
Fungal Species ◽  
Content Type ◽  
Human Fungal Pathogen ◽  
Red Cedar ◽  
Immunosuppressed Patients ◽  
Western Red Cedar

ABSTRACT Cryptococcus neoformans is a pathogen that is common in immunosuppressed patients. It can be treated with amphotericin B and fluconazole, but the mortality rate remains 15 to 30%. Thus, novel and more effective anticryptococcal therapies are needed. The troponoids are based on natural products isolated from western red cedar, and have a broad range of antimicrobial activities. Extracts of western red cedar inhibit the growth of several fungal species, but neither western red cedar extracts nor troponoid derivatives have been tested against C. neoformans. We screened 56 troponoids for their ability to inhibit C. neoformans growth and to assess whether they may be attractive candidates for development into anticryptococcal drugs. We determined MICs at which the compounds inhibited 80% of cryptococcal growth relative to vehicle-treated controls and identified 12 compounds with MICs ranging from 0.2 to 15 μM. We screened compounds with MICs of ≤20 μM for cytotoxicity in liver hepatoma cells. Fifty percent cytotoxicity values (CC50s) ranged from 4 to >100 μM. The therapeutic indexes (TI, CC50/MIC) for most of the troponoids were fairly low, with most being <8. However, two compounds had TI values that were >8, including a tropone with a TI of >300. These tropones are fungicidal and are not antagonistic when used in combination with fluconazole or amphotericin B. Inhibition by these two tropones remains unchanged under conditions favoring cryptococcal capsule formation. These data support the hypothesis that troponoids may be a productive scaffold for the development of novel anticryptococcal therapies.

scholarly journals Dangerous Liaisons: Interactions of Cryptococcus neoformans with Host Phagocytes

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 891 ◽  
Author(s):  
Elizabeth A. Gaylord ◽  
Hau Lam Choy ◽  
Tamara L. Doering
Keyword(s):  
Cryptococcus Neoformans ◽  
Fungal Pathogen ◽  
Host Cells ◽  
Cell Transfer ◽  
Cryptococcal Infection ◽  
Host Interaction ◽  
Opportunistic Fungal Pathogen ◽  
Cell To Cell Transfer ◽  
The Brain ◽  
Lateral Cell

Cryptococcus neoformans is an opportunistic fungal pathogen and a leading cause of death in immunocompromised individuals. The interactions of this yeast with host phagocytes are critical to disease outcome, and C. neoformans is equipped with an array of factors to modulate these processes. Cryptococcal infection begins with the deposition of infectious particles into the lungs, where the fungal cells deploy various antiphagocytic factors to resist internalization by host cells. If the cryptococci are still engulfed, they can survive and proliferate within host cells by modulating the phagolysosome environment in which they reside. Lastly, cryptococcal cells may escape from phagocytes by host cell lysis, nonlytic exocytosis, or lateral cell-to-cell transfer. The interactions between C. neoformans and host phagocytes also influence the dissemination of this pathogen to the brain, where it may cross the blood-brain barrier and cause an often-fatal meningoencephalitis. In this review, we highlight key cryptococcal factors involved in various stages of cryptococcal-host interaction and pathogenesis.

scholarly journals Volatile organic compound patterns predict fungal trophic mode and lifestyle

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yuan Guo ◽  
Werner Jud ◽  
Fabian Weikl ◽  
Andrea Ghirardo ◽  
Robert R. Junker ◽  
...  
Keyword(s):  
Organic Compound ◽  
Fungal Species ◽  
Chemical Diversity ◽  
Phenotypic Integration ◽  
Ecological Studies ◽  
Volatile Organic ◽  
Ecological Importance ◽  
Fungal Interactions ◽  
Computational Analyses ◽  
Different Levels

AbstractFungi produce a wide variety of volatile organic compounds (VOCs), which play central roles in the initiation and regulation of fungal interactions. Here we introduce a global overview of fungal VOC patterns and chemical diversity across phylogenetic clades and trophic modes. The analysis is based on measurements of comprehensive VOC profiles of forty-three fungal species. Our data show that the VOC patterns can describe the phyla and the trophic mode of fungi. We show different levels of phenotypic integration (PI) for different chemical classes of VOCs within distinct functional guilds. Further computational analyses reveal that distinct VOC patterns can predict trophic modes, (non)symbiotic lifestyle, substrate-use and host-type of fungi. Thus, depending on trophic mode, either individual VOCs or more complex VOC patterns (i.e., chemical communication displays) may be ecologically important. Present results stress the ecological importance of VOCs and serve as prerequisite for more comprehensive VOCs-involving ecological studies.

scholarly journals Pneumocystis Melanins Confer Enhanced Organism Viability

2006 ◽  
Vol 5 (6) ◽  
pp. 916-923 ◽  
Author(s):  
Crystal R. Icenhour ◽  
Theodore J. Kottom ◽  
Andrew H. Limper
Keyword(s):  
Fungal Pathogen ◽  
Pneumocystis Carinii ◽  
Environmental Stressors ◽  
Resonance Spectroscopy ◽  
Reverse Transcription Pcr ◽  
Spin Resonance ◽  
Opportunistic Fungal Pathogen ◽  
Adverse Environmental Conditions ◽  
Previous Identification

ABSTRACT Pneumocystis continues to represent an important opportunistic fungal pathogen of those with compromised immunity. Thus, it is crucial to identify factors that affect its viability and pathogenicity. We previously reported the first identification of melanins in Pneumocystis. In the present study, we sought to further characterize these components and define the function for these melanins. Melanins extracted from Pneumocystis and melanized Pneumocystis cells were analyzed by electron spin resonance spectroscopy, revealing spectra consistent with melanins from other fungi. Immunofluorescence assays using anti-melanin monoclonal antibodies showed that melanins are widely present across Pneumocystis host species, including mouse-, ferret-, and human-derived Pneumocystis organisms, as well as Pneumocystis carinii derived from rat. Using immunoelectron microscopy, melanins were found to localize to the cell wall and cytoplasm of P. carinii cysts, as well as to intracystic bodies within mature cysts. Next, the role of melanins on the maintenance of Pneumocystis viability was determined by using quantitative reverse transcription-PCR measurement of the heat shock protein mRNA under adverse environmental conditions. Using a new method to promote the melanization of Pneumocystis, we observed that strongly melanized Pneumocystis retained viability to a greater degree when exposed to UV irradiation or desiccation compared to less-pigmented organisms. These studies support our previous identification of Pneumocystis melanins across the genus, further characterize these Pneumocystis components, and demonstrate that melanins protect Pneumocystis from environmental stressors.

scholarly journals Burkholderia species in human infections in Mexico: Identification of B. cepacia, B. contaminans, B. multivorans, B. vietnamiensis,B. pseudomallei and a new Burkholderia species

2021 ◽  
Vol 15 (6) ◽  
pp. e0009541
Author(s):  
Georgina Meza-Radilla ◽  
Violeta Larios-Serrato ◽  
Rigoberto Hernández-Castro ◽  
J. Antonio Ibarra ◽  
Paulina Estrada-de los Santos
Keyword(s):  
Sensu Stricto ◽  
Clinical Settings ◽  
Correct Identification ◽  
Opportunistic Pathogens ◽  
Burkholderia Species ◽  
Medical Centers ◽  
Accurate Treatment ◽  
Immunosuppressed Patients ◽  
Human Infections ◽  
First Time

Background Burkholderia sensu stricto is comprised mainly of opportunistic pathogens. This group is widely distributed in the environment but is especially important in clinical settings. In Mexico, few species have been correctly identified among patients, most often B. cepacia is described. Methodology/Principal findings In this study, approximately 90 strains identified as B. cepacia with the VITEK2 system were isolated from two medical centers in Mexico City and analyzed by MLSA, BOX-PCR and genome analysis. The initial identification of B. cepacia was confirmed for many strains, but B. contaminans, B. multivorans and B. vietnamiensis were also identified among clinical strains for the first time in hospitals in Mexico. Additionally, the presence of B. pseudomallei was confirmed, and a novel species within the B. cepacia complex was documented. Several strains misidentified as B. cepacia actually belong to the genera Pseudomonas, Stenotrophomonas and Providencia. Conclusions/Significance The presence of different Burkholderia species in Mexico was confirmed. Correct identification of Burkholderia species is important to provide accurate treatment for immunosuppressed patients.

scholarly journals Aspergillus fumigatus Acetate Utilization Impacts Virulence Traits and Pathogenicity

mBio ◽  
2021 ◽  
Author(s):  
Laure Nicolas Annick Ries ◽  
Patricia Alves de Castro ◽  
Lilian Pereira Silva ◽  
Clara Valero ◽  
Thaila Fernanda dos Reis ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Fungal Pathogen ◽  
Carbon Sources ◽  
Body Fluids ◽  
Peripheral Tissues ◽  
Content Type ◽  
Virulence Traits ◽  
Acetate Utilization ◽  
Opportunistic Fungal Pathogen

Aspergillus fumigatus is an opportunistic fungal pathogen in humans. During infection, A. fumigatus is predicted to use host carbon sources, such as acetate, present in body fluids and peripheral tissues, to sustain growth and promote colonization and invasion.

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