scholarly journals Temporal shifts in the mycobiome structure and network architecture associated with a rat (Rattus norvegicus) deep partial-thickness cutaneous burn

2019 ◽  
Vol 58 (1) ◽  
pp. 107-117 ◽  
Author(s):  
Fatemeh Sanjar ◽  
Alan J Weaver ◽  
Trent J Peacock ◽  
Jesse Q Nguyen ◽  
Kenneth S Brandenburg ◽  
...  

Abstract With a diverse physiological interface to colonize, mammalian skin is the first line of defense against pathogen invasion and harbors a consortium of microbes integral in maintenance of epithelial barrier function and disease prevention. While the dynamic roles of skin bacterial residents are expansively studied, contributions of fungal constituents, the mycobiome, are largely overlooked. As a result, their influence during skin injury, such as disruption of skin integrity in burn injury and impairment of host immune defense system, is not clearly delineated. Burn patients experience a high risk of developing hard-to-treat fungal infections in comparison to other hospitalized patients. To discern the changes in the mycobiome profile and network assembly during cutaneous burn-injury, a rat scald burn model was used to survey the mycobiome in healthy (n = 30) (sham-burned) and burned (n = 24) skin over an 11-day period. The healthy skin demonstrated inter-animal heterogeneity over time, while the burned skin mycobiome transitioned toward a temporally stabile community with declining inter-animal variation starting at day 3 post-burn injury. Driven primarily by a significant increase in relative abundance of Candida, fungal species richness and abundance of the burned skin decreased, especially in days 7 and 11 post-burn. The network architecture of rat skin mycobiome displayed community reorganization toward increased network fragility and decreased stability compared to the healthy rat skin fungal network. This study provides the first account of the dynamic diversity observed in the rat skin mycobiome composition, structure, and network assembly associated with postcutaneous burn injury.

2021 ◽  
Vol 12 ◽  
Author(s):  
Yujie Zhou ◽  
Lei Cheng ◽  
Yu L. Lei ◽  
Biao Ren ◽  
Xuedong Zhou

Mucosa protects the body against external pathogen invasion. However, pathogen colonies on the mucosa can invade the mucosa when the immunosurveillance is compromised, causing mucosal infection and subsequent diseases. Therefore, it is necessary to timely and effectively monitor and control pathogenic microorganisms through mucosal immunity. Candida albicans is the most prevalent fungi on the mucosa. The C. albicans colonies proliferate and increase their virulence, causing severe infectious diseases and even death, especially in immunocompromised patients. The normal host mucosal immune defense inhibits pathogenic C. albicans through stepwise processes, such as pathogen recognition, cytokine production, and immune cell phagocytosis. Herein, the current advances in the interactions between C. albicans and host mucosal immune defenses have been summarized to improve understanding on the immune mechanisms against fungal infections.


2021 ◽  
Vol 7 (3) ◽  
pp. 202
Author(s):  
Johannes Delgado-Ospina ◽  
Junior Bernardo Molina-Hernández ◽  
Clemencia Chaves-López ◽  
Gianfranco Romanazzi ◽  
Antonello Paparella

Background: The role of fungi in cocoa crops is mainly associated with plant diseases and contamination of harvest with unwanted metabolites such as mycotoxins that can reach the final consumer. However, in recent years there has been interest in discovering other existing interactions in the environment that may be beneficial, such as antagonism, commensalism, and the production of specific enzymes, among others. Scope and approach: This review summarizes the different fungi species involved in cocoa production and the cocoa supply chain. In particular, it examines the presence of fungal species during cultivation, harvest, fermentation, drying, and storage, emphasizing the factors that possibly influence their prevalence in the different stages of production and the health risks associated with the production of mycotoxins in the light of recent literature. Key findings and conclusion: Fungi associated with the cocoa production chain have many different roles. They have evolved in a varied range of ecosystems in close association with plants and various habitats, affecting nearly all the cocoa chain steps. Reports of the isolation of 60 genera of fungi were found, of which only 19 were involved in several stages. Although endophytic fungi can help control some diseases caused by pathogenic fungi, climate change, with increased rain and temperatures, together with intensified exchanges, can favour most of these fungal infections, and the presence of highly aggressive new fungal genotypes increasing the concern of mycotoxin production. For this reason, mitigation strategies need to be determined to prevent the spread of disease-causing fungi and preserve beneficial ones.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1434
Author(s):  
Hiran A. Ariyawansa ◽  
Ichen Tsai ◽  
Jian-Yuan Wang ◽  
Patchareeya Withee ◽  
Medsaii Tanjira ◽  
...  

Camellia sinensis is one of the major crops grown in Taiwan and has been widely cultivated around the island. Tea leaves are prone to various fungal infections, and leaf spot is considered one of the major diseases in Taiwan tea fields. As part of a survey on fungal species causing leaf spots on tea leaves in Taiwan, 19 fungal strains morphologically similar to the genus Diaporthe were collected. ITS (internal transcribed spacer), tef1-α (translation elongation factor 1-α), tub2 (beta-tubulin), and cal (calmodulin) gene regions were used to construct phylogenetic trees and determine the evolutionary relationships among the collected strains. In total, six Diaporthe species, including one new species, Diaporthe hsinchuensis, were identified as linked with leaf spot of C. sinensis in Taiwan based on both phenotypic characters and phylogeny. These species were further characterized in terms of their pathogenicity, temperature, and pH requirements under laboratory conditions. Diaporthe tulliensis, D. passiflorae, and D. perseae were isolated from C. sinensis for the first time. Furthermore, pathogenicity tests revealed that, with wound inoculation, only D. hongkongensis was pathogenic on tea leaves. This investigation delivers the first assessment of Diaporthe taxa related to leaf spots on tea in Taiwan.


2021 ◽  
Author(s):  
Rossana de Aguiar Cordeiro ◽  
Bruno Nascimento da Silva ◽  
Ana Luiza Ribeiro de Aguiar ◽  
Livia Maria Galdino Pereira ◽  
Fernando Victor Monteiro Portela ◽  
...  

Abstract Invasive fungal infections (IFIs) are important worldwide health problem, affecting the growing population of immunocompromised patients. Although the majority of IFIs are caused by Candida spp., other fungal species have been increasingly recognized as relevant opportunistic pathogens. Trichosporon spp. are members of skin and gut human microbiota. Since 1980’s, invasive trichosporonosis has been considered a significant cause of fungemia in patients with hematological malignancies. As prolonged antibiotic therapy is an important risk factor for IFIs, the present study investigated if vancomycin enhances growth and virulence of Trichosporon. Vancomycin was tested against T. inkin (n = 6) and T. asahii (n = 6) clinical strains. Planktonic cells were evaluated for their metabolic activity and virulence against Caenorhabditis elegans. Biofilms were evaluated for metabolic activity, biomass production, amphotericin B tolerance, induction of persister cells, and ultrastructure. Vancomycin stimulated planktonic growth of Trichosporon spp., increased tolerance to AMB, and potentiates virulence against C. elegans. Vancomycin stimulated growth (metabolic activity and biomass) of Trichosporon spp. biofilms during all stages of development. The antibiotic increased the number of persister cells inside Trichosporon biofilms. These cells showed higher tolerance to AMB than persister cells from VAN-free biofilms. Microscopic analysis showed that VAN increased production of extracellular matrix and cells in T. inkin and T. asahii biofilms. These results suggest that antibiotic exposure may have a direct impact on the pathophysiology of opportunistic trichosporonosis in patients at risk. Lay abstract This study showed that the vancomycin stimulated Trichosporon growth, induced morphological and physiological changes on their biofilms, and also enhanced their in vivo virulence. Although speculative, the stimulatory effect of vancomycin on fungal cells should be considered in a clinical scenario.


2021 ◽  
Vol 7 (9) ◽  
pp. 720
Author(s):  
Maryam Roudbary ◽  
Sunil Kumar ◽  
Awanish Kumar ◽  
Lucia Černáková ◽  
Fatemeh Nikoomanesh ◽  
...  

Patients with severe COVID-19, such as individuals in intensive care units (ICU), are exceptionally susceptible to bacterial and fungal infections. The most prevalent fungal infections are aspergillosis and candidemia. Nonetheless, other fungal species (for instance, Histoplasma spp., Rhizopus spp., Mucor spp., Cryptococcus spp.) have recently been increasingly linked to opportunistic fungal diseases in COVID-19 patients. These fungal co-infections are described with rising incidence, severe illness, and death that is associated with host immune response. Awareness of the high risks of the occurrence of fungal co-infections is crucial to downgrade any arrear in diagnosis and treatment to support the prevention of severe illness and death directly related to these infections. This review analyses the fungal infections, treatments, outcome, and immune response, considering the possible role of the microbiome in these patients. The search was performed in Medline (PubMed), using the words “fungal infections COVID-19”, between 2020–2021.


2019 ◽  
Vol 16 (4) ◽  
pp. 461-466
Author(s):  
Marco Zuccolo ◽  
Sabrina Dallavalle ◽  
Raffaella Cincinelli ◽  
Luce Mattio ◽  
Stefania Mazzini ◽  
...  

Background: Superficial fungal infections are the most common fungal diseases in humans, affecting more than 25% of the population worldwide. Methods: In the present study, we have investigated the activity of kakuol, a natural compound isolated from the rhizomes of Asarum sieboldii, and some analogues, against various dermatophytes and pharmacologically relevant yeasts. Results: One of the tested compounds, 2-acryloyl-4,5-methylenedioxyphenol, showed a broadspectrum activity against most of the fungal species assayed, resulting particularly effective against dermatophyte strains (MIC values in the range of 0.25-0.5 µg/mL, two/four-fold lower than the positive control miconazole). Conclusion: The results suggest that this molecule can be considered a promising starting point for the development of new antifungal compounds.


2019 ◽  
Vol 16 (32) ◽  
pp. 894-898
Author(s):  
D. F. SILVA ◽  
H. D. NETO ◽  
M. D. L. FERREIRA ◽  
A. A. O. FILHO ◽  
E. O. LIMA

β-citronellol (3,7-dimethyl-6-octen-1-ol) has been exhibiting a number of pharmacological effects that creates interest about its antimicrobial potential, since several substances of the monoterpene class have already demonstrated to possess activity in this profile. In addition, the emergence of fungal species resistant to current pharmacotherapy poses a serious challenge to health systems, making it necessary to search for new effective therapeutic alternatives to deal with this problem. In this study, the antimicrobial profile of β-citronellol was analyzed. The Prediction of Activity Spectra for Substances (PASS) online software was used to study the antimicrobial activity of the β-citronellol molecule by the use of in silico analysis. In contrast, an in vitro antifungal study of this monoterpene was carried out. For this purpose, the Minimum Inhibitory Concentration (MIC) was determined by the microdilution technique in 96-well plates in Saboraud Dextrose Broth/RPMI against sensitive strains of Candida albicans, and this assay was performed in duplicate. In the in silico analysis of the antimicrobial profile, it was revealed that the monoterpene β-citronellol had a diverse antimicrobial bioactivity profile. For the antifungal activity, it presented a percentage value with Pa: 58.4% (predominant) and its MIC of 128 μg/mL, which was equivalent for all strains tested. The in silico study of the β-citronellol molecule allowed us to consider that the monoterpenoid is very likely to be bioactive against agents that cause fungal infections.


2021 ◽  
Vol 156 (Supplement_1) ◽  
pp. S133-S133
Author(s):  
A D Pyden ◽  
I Solomon ◽  
A Laga Canales

Abstract Introduction/Objective Opportunistic infections by fungi are a major source of morbidity and mortality in patients suffering from extensive burn wounds. Here we review a series of cases of infections by multiple fungi in burn wounds as diagnosed by histopathology and outline the key features for the pathologist to include in the report. Methods/Case Report Biopsies from patients with more than one fungal species identified in the laboratory in a concurrent culture or by PCR were included in this study. Three cases are presented with multiple fungi identified. Each case had yeast and at least one different hyaline mold species present on pathology; two cases additionally had mucormycetes present, with angioinvasion in one case. All organisms requiried microbiologic cultures and variably required molecular testing for full identification. Results (if a Case Study enter NA) N/A Conclusion Pathologists should be aware of the possibility of infection by multiple fungal species in burn wounds. Fungal morphology in tissue sections should allow for detection and distinction of mucormyctes and other hyaline molds. Histopathologic correlation with culture and/or PCR results is essential to distinguish potential contaminants from true infection.


mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
A. Luraschi ◽  
S. Richard ◽  
J. M. G. C. F. Almeida ◽  
M. Pagni ◽  
M. T. Cushion ◽  
...  

ABSTRACTThe genusPneumocystisencompasses fungal species that colonize mammals’ lungs with host specificity. Should the host immune system weaken, the fungal species can cause severe pneumonia. The life cycle of these pathogens is poorly known, mainly because anin vitroculture method has not been established. Both asexual and sexual cycles would occur. Trophic cells, the predominant forms during infection, could multiply asexually but also enter into a sexual cycle. Comparative genomics revealed a single mating type locus, including plus and minus genes, suggesting that primary homothallism involving self-fertility of each strain is the mode of reproduction ofPneumocystisspecies. We identified and analyzed the expression of themam2andmap3genes encoding the receptors for plus and minus pheromones using reverse transcriptase PCR, in both infected mice and bronchoalveolar lavage fluid samples from patients withPneumocystispneumonia. Both receptors were most often concomitantly expressed during infection, revealing that both pheromone-receptor systems are involved in the sexual cycle. Themap3transcripts were subject to alternative splicing. Using immunostaining, we investigated the presence of the pheromone receptors at the surfaces ofPneumocystiscells from a patient. The staining tools were first assessed inSaccharomyces cerevisiaedisplaying thePneumocystisreceptors at their cellular surface. Both receptors were present at the surfaces of the vast majority of the cells that were likely trophic forms. The receptors might have a role in mate recognition and/or postfertilization events. Their presence at the cell surface might facilitate outbreeding versus inbreeding of self-fertile strains.IMPORTANCEThe fungi belonging to the genusPneumocystismay cause severe pneumonia in immunocompromised humans, a disease that can be fatal if not treated. This disease is nowadays one of the most frequent invasive fungal infections worldwide. Whole-genome sequencing revealed that the sexuality of these fungi involves a single partner that can self-fertilize. Here, we report that two receptors recognizing specifically excreted pheromones are involved in this self-fertility within infected human lungs. Using fluorescent antibodies binding specifically to these receptors, we observed that most often, the fungal cells display both receptors at their surface. These pheromone-receptor systems might play a role in mate recognition and/or postfertilization events. They constitute an integral part of thePneumocystisobligate sexuality within human lungs, a cycle that is necessary for the dissemination of the fungus to new individuals.


2020 ◽  
Vol 6 (4) ◽  
pp. 308
Author(s):  
Joana Carvalho-Pereira ◽  
Filipa Fernandes ◽  
Ricardo Araújo ◽  
Jan Springer ◽  
Juergen Loeffler ◽  
...  

A new and easy polymerase chain reaction (PCR) multiplex strategy, for the identification of the most common fungal species involved in invasive fungal infections (IFI) was developed in this work. Two panels with species-specific markers were designed, the Candida Panel for the identification of Candida species, and the Filamentous Fungi Panel for the identification of Aspergillus species and Rhizopusarrhizus. The method allowed the correct identification of all targeted pathogens using extracted DNA or by colony PCR, showed no cross-reactivity with nontargeted species and allowed identification of different species in mixed infections. Sensitivity reached 10 to 1 pg of DNA and was suitable for clinical samples from sterile sites, with a sensitivity of 89% and specificity of 100%. Overall, the study showed that the new method is suitable for the identification of the ten most important fungal species involved in IFI, not only from positive blood cultures but also from clinical samples from sterile sites. The method provides a unique characteristic, of seeing the peak in the specific region of the panel with the correct fluorescence dye, that aids the ruling out of unspecific amplifications. Furthermore, the panels can be further customized, selecting markers for different species and/or resistance genes.


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