scholarly journals Virus Infection of Aspergillus fumigatus Compromises the Fungus in Intermicrobial Competition

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 686
Author(s):  
Hasan Nazik ◽  
Ioly Kotta-Loizou ◽  
Gabriele Sass ◽  
Robert H. A. Coutts ◽  
David A. Stevens
Keyword(s):  
Virus Infection ◽  
Aspergillus Fumigatus ◽  
Stress Responses ◽  
Fungal Pathogens ◽  
Clinical Settings ◽  
Virus Infections ◽  
Fungal Strains ◽  
Common Reference ◽  
Strain Virus ◽  
Free Strain

Aspergillus and Pseudomonas compete in nature, and are the commonest bacterial and fungal pathogens in some clinical settings, such as the cystic fibrosis lung. Virus infections of fungi occur naturally. Effects on fungal physiology need delineation. A common reference Aspergillus fumigatus strain, long studied in two (of many) laboratories, was found infected with the AfuPmV-1 virus. One isolate was cured of virus, producing a virus-free strain. Virus from the infected strain was purified and used to re-infect three subcultures of the virus-free fungus, producing six fungal strains, otherwise isogenic. They were studied in intermicrobial competition with Pseudomonasaeruginosa. Pseudomonas culture filtrates inhibited forming or preformed Aspergillus biofilm from infected strains to a greater extent, also seen when Pseudomonas volatiles were assayed on Aspergillus. Purified iron-chelating Pseudomonas molecules, known inhibitors of Aspergillus biofilm, reproduced these differences. Iron, a stimulus of Aspergillus, enhanced the virus-free fungus, compared to infected. All infected fungal strains behaved similarly in assays. We show an important consequence of virus infection, a weakening in intermicrobial competition. Viral infection may affect the outcome of bacterial–fungal competition in nature and patients. We suggest that this occurs via alteration in fungal stress responses, the mechanism best delineated here is a result of virus-induced altered Aspergillus iron metabolism.

scholarly journals Responses to Stress: Investigating the Role of Gender, Social Relationships, and Touch Avoidance in Italy

2021 ◽  
Vol 18 (2) ◽  
pp. 600
Author(s):  
Marcello Passarelli ◽  
Laura Casetta ◽  
Luca Rizzi ◽  
Raffaella Perrella
Keyword(s):  
Social Relationships ◽  
Stress Responses ◽  
Clinical Settings ◽  
Daily Stressors ◽  
Analysis Techniques ◽  
Touch Avoidance ◽  
Main Determinants ◽  
Reducing Stress ◽  
Social Level

Stress is a physiological response to internal and external events we call “stressors”. Response to the same daily stressors varies across individuals and seems to be higher for women. A possible explanation for this phenomenon is that women perceive sociality, relationships, and intimacy—important sources of both stress and wellbeing—differently from how men experience them. In this study, we investigate how gender, attachment, and touch avoidance predict stress responses on a sample of 335 Italians (216 females; age = 35.82 ± 14.32). Moreover, we analyze the network of relationships between these variables through multiple linear regression and exploratory network analysis techniques. The results recontextualize the role of gender in determining stress responses in terms of (lack of) confidence and touch avoidance toward family members; attitudes toward relationships seem to be the main determinants of stress responses. These results have implications for reducing stress in both clinical settings and at a social level.

scholarly journals Risk factors and disposition in development of the nervous system infections

2009 ◽  
Vol 62 (9-10) ◽  
pp. 461-467
Author(s):  
Ljiljana Nesic ◽  
Predrag Canovic ◽  
Zeljko Mijailovic ◽  
Jelena Djokovic
Keyword(s):  
Risk Factors ◽  
Nervous System ◽  
Virus Infection ◽  
Lupus Erythematosus ◽  
Bacterial Infections ◽  
Heart Diseases ◽  
Final Diagnosis ◽  
Medical Documentation ◽  
Virus Infections ◽  
Number Of Patients

Introduction. Although well protected, brain is not resistant to infection agents. Acute infections of our nervous system appear more often in children and in persons who have medical history data about previous disorders, especially disorders of the nervous system. It is difficult to list possible risk factors which can be responsible for the appearance of infections of CNS and the resulting conditions. It is often difficult or impossible to determine what previous neural damage was (trauma, anoxic damages etc.) from those appearing during infections of CNS. All-inclusive anamnestic research reduces the possibility of approximate judgments. Material and methods. The research was based on the retrospective analysis of medical documentation of 275 patients. All patients were divided into three groups according to the final diagnosis. The first group consisted of 125 patients who were treated for acute virus encephalitis, the second group consisted of 125 patients who were treated for acute bacterial meningoencephalitis and the third group consisted of 25 patients who were treated for cerebritis. Discussion. In our studies sample, the youngest patient was 3 years old and the oldest was 87 years old. The highest number of patients with virus infection of the CNS was in the group under 25 years of age (45.6%). The highest number of patients with bacterial infections of the CNS and cerebritis was in the group of patients over 45 years of age (64%, 37%). Conclusion. Risk factors were more present in bacterial infections of the nervous system and cerebrit thanin virus infection of CNS. In virus infections of the CNS, 28% of patients had some risk factor, most often-chronic ethylism, diabetes mellitus and acquired heart diseases. In bacterial infections of the CNS, 64% of patients had some predisposed factor. The most frequent factor of risk in these patients were chronic otitis (21.6%) and craniotrauma (14.4%). In cerebritis, risk factors were present in 76% of patients and they were: sepsis (20%), chronic otitis (12%) and systemic lupus erythematosus (8%).

scholarly journals The local antibody response to R.S. virus infection in the respiratory tract

1974 ◽  
Vol 72 (1) ◽  
pp. 111-120 ◽  
Author(s):  
R. Scott ◽  
P. S. Gardner
Keyword(s):  
Virus Infection ◽  
Respiratory Tract ◽  
Acute Phase ◽  
Respiratory Infections ◽  
Geometric Mean ◽  
High Titre ◽  
Virus Infections ◽  
Mean Values ◽  
Neutralizing Activity ◽  
Tract Infections

SUMMARYNasopharyngeal secretions were taken during the acute phase of illness from 66 infants and children admitted to hospital with lower respiratory tract infections. Second secretions were taken, after an interval of 7 days, from 33 of these patients. A significant increase in neutralizing activity to R.S. virus was demonstrated in the nasopharyngeal secretions of patients in response to severe R.S. virus infection. Seventeen out of 25 patients (68%) with R.S. virus infections developed a rise in secretory neutralizing titre, compared with only 1 out of 8 patients (13%) with respiratory infections not involving R.S. virus.A high titre of secretory neutralizing activity was found more often in the acute phase of illness in patients with R.S. virus infections, especially bronchiolitis, than in patients with respiratory infections not involving R.S. virus. Fifteen out of 34 patients (44%) with R.S. virus bronchiolitis were found to possess a neutralizing titre of 1/4 or more in their first secretions, compared with 4 out of 12 patients (33%) with R.S. virus infections other than bronchiolitis and 3 out of 20 patients (15%) with respiratory infections not involving R.S. virus.A quantitative analysis of the immunoglobulins present in the secretions indicated that IgA was the only immunoglobulin consistently present at a detectable concentration. The geometric mean values of IgA, IgM and IgG in the secretions examined were found to be 22·3, 4·3 and 5·3 mg./lOO ml. respectively.The neutralizing activity against R.S. virus, present in the secretions, was shown to be due to specific IgA antibody. This was accomplished by removing the neutralizing activitv in two secretions bv absorotion with anti-IaA serum.

Biosynthesis of selenium nanoparticles by Aspergillus flavus and Candida albicans and comparison of their effects with antifungal drugs

2021 ◽  
Author(s):  
Mahdi Hosseini Bafghi ◽  
Razieh Nazari ◽  
Majid Darroudi ◽  
Mohsen Zargar ◽  
Hossein Zarrinfar
Keyword(s):  
Candida Albicans ◽  
Aspergillus Flavus ◽  
Fungal Pathogens ◽  
Chemical Properties ◽  
Cost Effective ◽  
Antifungal Drugs ◽  
Selenium Nanoparticles ◽  
Fungal Strains ◽  
Vis Spectroscopy ◽  
Physical And Chemical

Abstract Biosynthesis of nanoparticles can stand as a replacement for the available chemical and physical methods by offering new procedures as green syntheses that have proved to be simple, biocompatible, safe, and cost-effective. Considering how nanoparticles with a size of 1 to 100 nanometers contain unique physical and chemical properties, recent reports are indicative of observing the antifungal qualities of selenium nanoparticles (Se-NPs). Recently, the observance of antifungal resistance towards different species of these fungi is often reported. Therefore, due to the antifungal effects of biological nanoparticles, this study aimed to investigate the exertion of these nanoparticles and evaluate their effects on the growth of fungal pathogens. Se-NPs were biosynthesized by the application of wet reduction method, which included specific concentrations of Aspergillus flavus and Candida albicans. The presence of nanoparticles was confirmed by methods such as UV-Vis spectroscopy, FT-IR analysis, and FESEM electron microscope that involved FESEM and EDAX diagram. The fungal strains were cultured in sabouraud dextrose agar medium to perform the sensitivity test based on the minimum inhibitory concentration (MIC) method in duplicate. The utilization of Se-NPs at concentrations of 1 µg/ ml and below resulted in zero growth of fungal agents. However, their growth was inhibited by antifungal drugs at concentrations of 2 µg/ ml and higher. Based on the obtained results, biological nanoparticles produced by fungal agents at different concentrations exhibited favorable inhibitory effects on the growth of fungal strains.

scholarly journals Selective induction of monocyte and not neutrophil-attracting chemokines after influenza A virus infection.

1996 ◽  
Vol 184 (3) ◽  
pp. 1191-1196 ◽  
Author(s):  
H Sprenger ◽  
R G Meyer ◽  
A Kaufmann ◽  
D Bussfeld ◽  
E Rischkowsky ◽  
...  
Keyword(s):  
Virus Infection ◽  
Influenza A Virus ◽  
Mononuclear Cell ◽  
Influenza A ◽  
Mononuclear Cells ◽  
Infected Tissue ◽  
Mononuclear Leukocytes ◽  
Virus Infections ◽  
Virus Model ◽  
Influenza A Virus Infection

It is characteristic for virus infections that monocytes/macrophages and lymphocytes infiltrate infected tissue while neutrophils are absent. To understand the mechanisms selectively attracting mononuclear cells in viral diseases, we examined in an influenza A virus model the expression and regulation of chemokines as candidate molecules responsible for the immigration of leukocytes into inflamed tissue. After influenza A virus infection of human monocytes, a rapid expression of the mononuclear cell attracting CC-chemokine genes MIP-1, MCP-1, and RANTES occurred which was followed by the release of chemokine proteins. In striking contrast to CC-chemokines, the expression of the prototype neutrophil CXC-chemoattractants IL-8 and GRO-alpha was completely suppressed after influenza A infection. The release of other neutrophil chemotactic factors was excluded by microchemotaxis assays. These results suggest that the virus-specific induction of mononuclear cell-attracting chemokines accounts for the preferential influx of mononuclear leukocytes into virus-infected tissue.

Viruses: immunosuppressive effects

1983 ◽  
Vol 303 (1114) ◽  
pp. 137-147 ◽  
Keyword(s):  
Virus Infection ◽  
Human Lymphocytes ◽  
Suppressor Cells ◽  
Experimental Models ◽  
Unresolved Issue ◽  
Interferon Production ◽  
Virus Infections ◽  
Resistance Factors ◽  
Secondary Infections ◽  
Genetically Determined

Many virus infections in man and other species are accompanied by immunosuppression. This is clearly important in terms of the susceptibility of the host to secondary infections. The immunosuppression may also aid and abet the growth and persistence of viruses. An unresolved issue is the extent to which the extent of this immunosuppression is determined by the virulence of the infecting virus or resistance factors in the host, and particularly by factors that are genetically determined. The mechanisms of viral immunosuppression are indirect and direct. Indirect mechanisms such as interferon production and suppressor cells induced by infection undoubtedly contribute to viral immunosuppression in experimental models of virus infection. In man the direct inactivation of immunologically responsive lymphocytes seems to be the most important mechanism. Moreover, the persistence of viruses in human lymphocytes is being increasingly recognized.

scholarly journals Unraveling the Multifaceted Nature of CD8 T Cell Exhaustion Provides the Molecular Basis for Therapeutic T Cell Reconstitution in Chronic Hepatitis B and C

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2563
Author(s):  
Valeria Barili ◽  
Andrea Vecchi ◽  
Marzia Rossi ◽  
Ilaria Montali ◽  
Camilla Tiezzi ◽  
...  
Keyword(s):  
T Cells ◽  
Chronic Hepatitis ◽  
T Cell ◽  
Hepatitis B ◽  
Chronic Hepatitis B ◽  
Cd8 T Cells ◽  
Stress Responses ◽  
T Cell Exhaustion ◽  
Virus Infections ◽  
Cell Exhaustion

In chronic hepatitis B and C virus infections persistently elevated antigen levels drive CD8+ T cells toward a peculiar differentiation state known as T cell exhaustion, which poses crucial constraints to antiviral immunity. Available evidence indicates that T cell exhaustion is associated with a series of metabolic and signaling deregulations and with a very peculiar epigenetic status which all together lead to reduced effector functions. A clear mechanistic network explaining how intracellular metabolic derangements, transcriptional and signaling alterations so far described are interconnected in a comprehensive and unified view of the T cell exhaustion differentiation profile is still lacking. Addressing this issue is of key importance for the development of innovative strategies to boost host immunity in order to achieve viral clearance. This review will discuss the current knowledge in HBV and HCV infections, addressing how innate immunity, metabolic derangements, extensive stress responses and altered epigenetic programs may be targeted to restore functionality and responsiveness of virus-specific CD8 T cells in the context of chronic virus infections.

scholarly journals Pleiotropic Roles of the Msi1-Like Protein Msl1 in Cryptococcus neoformans

2012 ◽  
Vol 11 (12) ◽  
pp. 1482-1495 ◽  
Author(s):  
Dong-Hoon Yang ◽  
Shinae Maeng ◽  
Anna K. Strain ◽  
Anna Floyd ◽  
Kirsten Nielsen ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Stress Responses ◽  
Fungal Pathogens ◽  
Independent Manner ◽  
Content Type ◽  
Antifungal Drug Resistance ◽  
Human Fungal Pathogen ◽  
Assembly Factor ◽  
Life Threatening ◽  
Stress Related Genes

ABSTRACT Msi1-like (MSIL) proteins contain WD40 motifs and have a pleiotropic cellular function as negative regulators of the Ras/cyclic AMP (cAMP) pathway and components of chromatin assembly factor 1 (CAF-1), yet they have not been studied in fungal pathogens. Here we identified and characterized an MSIL protein, Msl1, in Cryptococcus neoformans , which causes life-threatening meningoencephalitis in humans. Notably, Msl1 plays pleiotropic roles in C. neoformans in both cAMP-dependent and -independent manners largely independent of Ras. Msl1 negatively controls antioxidant melanin production and sexual differentiation, and this was repressed by the inhibition of the cAMP-signaling pathway. In contrast, Msl1 controls thermotolerance, diverse stress responses, and antifungal drug resistance in a Ras/cAMP-independent manner. Cac2, which is the second CAF-1 component, appears to play both redundant and distinct functions compared to the functions of Msl1. Msl1 is required for the full virulence of C. neoformans . Transcriptome analysis identified a group of Msl1-regulated genes, which include stress-related genes such as HSP12 and HSP78 . In conclusion, this study demonstrates pleiotropic roles of Msl1 in the human fungal pathogen C. neoformans , providing insight into a potential novel antifungal therapeutic target.

scholarly journals Immunoglobulin A Antibody Responses in Dengue Patients: a Useful Marker for Serodiagnosis of Dengue Virus Infection

2005 ◽  
Vol 12 (10) ◽  
pp. 1235-1237 ◽  
Author(s):  
M. Nawa ◽  
T. Takasaki ◽  
M. Ito ◽  
S. Inoue ◽  
K. Morita ◽  
...  
Keyword(s):  
Virus Infection ◽  
Dengue Virus ◽  
Immunoglobulin A ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Infections ◽  
Serum Samples ◽  
Dengue Virus Infection ◽  
Iga Antibody ◽  
Antibody Capture

ABSTRACT We determined the usefulness of an immunoglobulin A (IgA) antibody-capture enzyme-linked immunosorbent assay for serodiagnosis of dengue virus infections. The results indicate that the presence of IgA and IgM in serum samples assures recent primary dengue virus infection even with a single serum sample.

scholarly journals FOXO regulates RNA interference in Drosophila and protects from RNA virus infection

2015 ◽  
Vol 112 (47) ◽  
pp. 14587-14592 ◽  
Author(s):  
Michael J. Spellberg ◽  
Michael T. Marr
Keyword(s):  
Rna Interference ◽  
Virus Infection ◽  
Gene Silencing ◽  
Small Rna ◽  
Stress Responses ◽  
Posttranscriptional Regulation ◽  
Rna Virus ◽  
Regulation Of Gene Expression ◽  
Cellular Physiology ◽  
Metabolic Conditions

Small RNA pathways are important players in posttranscriptional regulation of gene expression. These pathways play important roles in all aspects of cellular physiology from development to fertility to innate immunity. However, almost nothing is known about the regulation of the central genes in these pathways. The forkhead box O (FOXO) family of transcription factors is a conserved family of DNA-binding proteins that responds to a diverse set of cellular signals. FOXOs are crucial regulators of cellular homeostasis that have a conserved role in modulating organismal aging and fitness. Here, we show that Drosophila FOXO (dFOXO) regulates the expression of core small RNA pathway genes. In addition, we find increased dFOXO activity results in an increase in RNA interference (RNAi) efficacy, establishing a direct link between cellular physiology and RNAi. Consistent with these findings, dFOXO activity is stimulated by viral infection and is required for effective innate immune response to RNA virus infection. Our study reveals an unanticipated connection among dFOXO, stress responses, and the efficacy of small RNA-mediated gene silencing and suggests that organisms can tune their gene silencing in response to environmental and metabolic conditions.

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