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Frontiers in Immunology 2024Equine asthma (EA) is a common lower airway disease in horses, but whether its pathogenesis is allergic is ambiguous. Extrinsic stimuli like hay dust induce acute...
INTRODUCTION
Equine asthma (EA) is a common lower airway disease in horses, but whether its pathogenesis is allergic is ambiguous. Extrinsic stimuli like hay dust induce acute exacerbation of clinical signs and sustained local neutrophilic inflammation in susceptible horses. is an EA stimulus, but it is unclear if it merely acts as an IgE-provoking allergen. We aimed to comprehensively analyze immunoglobulin (Ig) isotypes in EA, elucidating their binding to different antigens, and their quantities systemically in serum and locally in bronchoalveolar lavage fluid (BALF).
METHODS
Serum and BALF from healthy horses (HE, = 18) and horses with mild-moderate asthma (MEA, = 20) or severe asthma (SEA, = 24) were compared. Ig isotype (IgG1, IgG3/5, IgG4/7, IgG6, IgA, and IgE) binding to nine antigens ( lysate, and recombinant Asp f 1, Asp f 7, Asp f 8, dipeptidyl-peptidase 5, class II aldolase/adducin domain protein, glucoamylase, beta-hexosaminidase, and peptide hydrolase) was compared by enzyme-linked immunosorbent assays. Total Ig isotype contents were determined by bead-based assays.
RESULTS
MEA and SEA differed from HE but hardly from each other. Compared to HE, asthmatic horses showed increased anti- binding of IgG (BALF and serum) and IgA (BALF). Serum and BALF IgE binding and total IgE contents were similar between HE and EA. Single antigens, as well as lysate, yielded similar Ig binding patterns. Serum and BALF IgG1 binding to all antigens was increased in SEA and to several antigens in MEA. Serum IgG4/7 binding to two antigens was increased in SEA. BALF IgA binding to all antigens was increased in SEA and MEA. Total BALF IgG1 and IgG4/7 contents were increased in SEA, and serum IgG4/7 content was increased in MEA compared to HE. Yet, total isotype contents differentiated EA and HE less clearly than antigen-binding Ig.
DISCUSSION
immunogenicity was confirmed without identification of single dominant antigens here. provoked elevated BALF IgG1 and IgA binding, and these isotypes appear relevant for neutrophilic EA, which does not support allergy. BALF Ig isotype differentiation beyond IgE is crucial for a comprehensive analysis of immune responses to fungi in EA pathogenesis.
Topics: Animals; Horses; Aspergillus fumigatus; Bronchoalveolar Lavage Fluid; Asthma; Immunoglobulin G; Immunoglobulin A; Horse Diseases; Antigens, Fungal; Male; Neutrophils; Female; Immunoglobulin E; Antibodies, Fungal
PubMed: 38953030
DOI: 10.3389/fimmu.2024.1406794 -
Research Square Sep 2023, an important pulmonary fungal pathogen causing several diseases collectively called aspergillosis, relies on asexual spores (conidia) for initiating host infection....
, an important pulmonary fungal pathogen causing several diseases collectively called aspergillosis, relies on asexual spores (conidia) for initiating host infection. Here, we used a phylogenomic approach to compare proteins in the conidial surface of , two closely related non-pathogenic species, and , and the cryptic pathogen . After identifying 62 proteins uniquely expressed on the conidial surface, we assessed null mutants for 42 genes encoding conidial proteins. Deletion of 33 of these genes altered susceptibility to macrophage killing, penetration and damage to epithelial cells, and cytokine production. Notably, a gene that encodes glycosylasparaginase, which modulates levels of the host pro-inflammatory cytokine IL-1β, is important for infection in an immunocompetent murine model of fungal disease. These results suggest that conidial surface proteins and effectors are important for evasion and modulation of the immune response at the onset of fungal infection.
PubMed: 37790311
DOI: 10.21203/rs.3.rs-3306535/v1 -
Mycopathologia Jun 2024Aspergillosis encompasses a wide range of clinical conditions based on the interaction between Aspergillus and the host. It ranges from colonization to invasive... (Review)
Review
Aspergillosis encompasses a wide range of clinical conditions based on the interaction between Aspergillus and the host. It ranges from colonization to invasive aspergillosis. The human lung provides an entry door for Aspergillus. Aspergillus has virulence characteristics such as conidia, rapid growth at body temperature, and the production of specific proteins, carbohydrates, and secondary metabolites that allow A. fumigatus to infiltrate the lung's alveoli and cause invasive aspergillosis. Alveolar epithelial cells play an important role in both fungus clearance and immune cell recruitment via cytokine release. Although the innate immune system quickly clears conidia in immunocompetent hosts, A. fumigatus has evolved multiple virulence factors in order to escape immune response such as ROS detoxifying enzymes, the rodlet layer, DHN-melanin and toxins. Bacterial co-infections or interactions can alter the immune response, impact Aspergillus growth and virulence, enhance biofilm formation, confound diagnosis, and reduce treatment efficacy. The gut microbiome's makeup influences pulmonary immune responses generated by A. fumigatus infection and vice versa. The real-time PCR for Aspergillus DNA detection might be a particularly useful tool to diagnose pulmonary aspergillosis. Metagenomics analyses allow quick and easy detection and identification of a great variety of fungi in different clinical samples, although optimization is still required particularly for the use of NGS techniques. This review will analyze the current state of aspergillosis in light of recent discoveries in the microbiota and mycobiota.
Topics: Humans; Aspergillosis; Mycobiome; Aspergillus fumigatus; Aspergillus; Virulence Factors; Microbiota; Virulence; Metagenomics; Host-Pathogen Interactions
PubMed: 38864956
DOI: 10.1007/s11046-024-00853-2 -
Chinese Medical Journal Aug 2023Previous research demonstrated that a homozygous mutation of g.136372044G>A (S12N) in caspase recruitment domain family member 9 ( CARD9 ) is critical for producing...
BACKGROUND
Previous research demonstrated that a homozygous mutation of g.136372044G>A (S12N) in caspase recruitment domain family member 9 ( CARD9 ) is critical for producing Aspergillus fumigatus -induced ( Af -induced) T helper 2 (T H 2)-mediated responses in allergic bronchopulmonary aspergillosis (ABPA). However, it remains unclear whether the CARD9S12N mutation, especially the heterozygous occurrence, predisposes the host to ABPA.
METHODS
A total of 61 ABPA patients and 264 controls (including 156 healthy controls and 108 asthma patients) were recruited for sequencing the CARD9 locus to clarify whether patients with this heterozygous single-nucleotide polymorphisms are predisposed to the development of ABPA. A series of in vivo and in vitro experiments, such as quantitative real-time polymerase chain reaction, flow cytometry, and RNA isolation and quantification, were used to illuminate the involved mechanism of the disease.
RESULTS
The presence of the p.S12N mutation was associated with a significant risk of ABPA in ABPA patients when compared with healthy controls and asthma patients, regardless of Aspergillus sensitivity. Relative to healthy controls without relevant allergies, the mutation of p.S12N was associated with a significant risk of ABPA (OR: 2.69 and 4.17 for GA and AA genotypes, P = 0.003 and 0.029, respectively). Compared with patients with asthma, ABPA patients had a significantly higher heterozygous mutation (GA genotype), indicating that p.S12N might be a significant ABPA-susceptibility locus ( aspergillus sensitized asthma: OR: 3.02, P = 0.009; aspergillus unsensitized asthma: OR: 2.94, P = 0.005). The mutant allele was preferentially expressed in ABPA patients with heterozygous CARD9S12N , which contributes to its functional alterations to facilitate Af -induced T H 2-mediated ABPA development. In terms of mechanism, Card9 wild-type ( Card9WT ) expression levels decreased significantly due to Af -induced decay of its messenger RNA compared to the heterozygous Card9S12N . In addition, ABPA patients with heterozygous CARD9S12N had increased Af -induced interleukin-5 production.
CONCLUSION
Our study provides the genetic evidence showing that the heterozygous mutation of CARD9S12N , followed by allele expression imbalance of CARD9S12N , facilitates the development of ABPA.
Topics: Humans; Aspergillosis, Allergic Bronchopulmonary; Aspergillus fumigatus; Asthma; Aspergillus; Mutation; CARD Signaling Adaptor Proteins
PubMed: 37461235
DOI: 10.1097/CM9.0000000000002786 -
Journal of Fungi (Basel, Switzerland) Sep 2023This overview of reviews (i.e., an umbrella review) is designed to reappraise the validity of systematic reviews (SRs) and meta-analyses related to the performance of... (Review)
Review
An Overview of Systematic Reviews of Polymerase Chain Reaction (PCR) for the Diagnosis of Invasive Aspergillosis in Immunocompromised People: A Report of the Fungal PCR Initiative (FPCRI)-An ISHAM Working Group.
This overview of reviews (i.e., an umbrella review) is designed to reappraise the validity of systematic reviews (SRs) and meta-analyses related to the performance of PCR tests for the diagnosis of invasive aspergillosis in immunocompromised patients. The methodological quality of the SRs was assessed using the AMSTAR-2 checklist; the quality of the evidence (QOE) within each SR was appraised following the GRADE approach. Eight out of 12 SRs were evaluated for qualitative and quantitative assessment. Five SRs evaluated PCR on bronchoalveolar lavage fluid (BAL) and three on blood specimens. The eight SRs included 167 overlapping reports (59 evaluating PCR in blood specimens, and 108 in BAL), based on 107 individual primary studies (98 trials with a cohort design, and 19 with a case-control design). In BAL specimens, the mean sensitivity and specificity ranged from 0.57 to 0.91, and from 0.92 to 0.97, respectively (QOE: very low to low). In blood specimens (whole blood or serum), the mean sensitivity ranged from 0.57 to 0.84, and the mean specificity from 0.58 to 0.95 (QOE: low to moderate). Across studies, only a low proportion of AMSTAR-2 critical domains were unmet (1.8%), demonstrating a high quality of methodological assessment. Conclusions. Based on the overall methodological assessment of the reviews included, on average we can have high confidence in the quality of results generated by the SRs.
PubMed: 37888223
DOI: 10.3390/jof9100967 -
Frontiers in Cellular and Infection... 2023The diagnosis of cutaneous manifestations of deep mycoses relies on both histopathological and direct examinations. Yet, the current diagnostic criteria cannot prevent...
INTRODUCTION
The diagnosis of cutaneous manifestations of deep mycoses relies on both histopathological and direct examinations. Yet, the current diagnostic criteria cannot prevent missed cases, including invasive aspergillosis, which requires the development of a novel diagnostic approach and imaging tools. We recently introduced the use of dynamic full-field optical coherence tomography (D-FF-OCT) in fungal diagnostics with a definition approaching that of conventional microscopy and the ability to return metabolic information regarding different fungal species. The present work focuses on subcellular dynamics and live-cell imaging of with D-FF-OCT to follow the fungal growth stages.
METHODS
The ATCC 204305 quality-control strain was used for all imaging experiments, following incubation times varying between 24 and 72 h at 30°C in a humidified chamber on Sabouraud dextrose agar. Fungal growth was subsequently monitored with D-FF-OCT for up to 5 h at room temperature and following the pharmacological stress of either voriconazole, amphotericin B, or caspofungin gradient concentration.
RESULTS
D-FF-OCT images allow not only the visualization of intracellular trafficking of vacuoles but also an evolving dynamic segmentation of conidiophores depending on the chronological development and aging of the hyphae or the effect of antifungal treatment. The same applies to conidial heads, with the most intense D-FF-OCT signal coming from vesicles, revealing a changing dynamic within a few hours only, as well as complete extinction following subsequent drying of the Sabouraud dextrose agar.
DISCUSSION
These results provide additional data on the ability of D-FF-OCT to monitor some of the main life cycle processes, dynamics, and intracellular trafficking of vacuoles in , with or without the effect of pharmacological stress. Such complementary metabolic information could help both clinicians and microbiologists in either mechanistic studies toward experimental mycology or the development of a potential D-FF-OCT-guided diagnosis of superficial fungal infections.
Topics: Aspergillus fumigatus; Tomography, Optical Coherence; Agar; Antifungal Agents; Glucose
PubMed: 37502605
DOI: 10.3389/fcimb.2023.1183340 -
The Lancet Regional Health. Western... Nov 2023New and emerging risks for invasive aspergillosis (IA) bring the need for contemporary analyses of the epidemiology and outcomes of IA, in order to improve clinical...
BACKGROUND
New and emerging risks for invasive aspergillosis (IA) bring the need for contemporary analyses of the epidemiology and outcomes of IA, in order to improve clinical practice.
METHODS
The study was a retrospective, multicenter, cohort design of proven and probable IA in adults from 10 Australasian tertiary centres (January 2017-December 2020). Descriptive analyses were used to report patients' demographics, predisposing factors, mycological characteristics, diagnosis and management. Accelerated failure-time model was employed to determine factor(s) associated with 90-day all-cause mortality (ACM).
FINDINGS
Of 382 IA episodes, 221 (in 221 patients) fulfilled inclusion criteria - 53 proven and 168 probable IA. Median patient age was 61 years (IQR 51-69). Patients with haematologic malignancies (HM) comprised 49.8% of cases. Fifteen patients (6.8%) had no pre-specified immunosuppression and eleven patients (5.0%) had no documented comorbidity. Only 30% of patients had neutropenia. Of 170 isolates identified, 40 (23.5%) were identified as non- species complex. Azole-resistance was present in 3/46 (6.5%) of isolates. Ninety-day ACM was 30.3%. HM (HR 1.90; 95% CI 1.04-3.46, p = 0.036) and ICU admission (HR 4.89; 95% CI 2.93-8.17, p < 0.001) but not neutropenia (HR 1.45; 95% CI 0.88-2.39, p = 0.135) were associated with mortality. Chronic kidney disease was also a significant predictor of death in the HM subgroup (HR 3.94; 95% CI 1.15-13.44, p = 0.028).
INTERPRETATION
IA is identified in high number of patients with mild/no immunosuppression in our study. The relatively high proportion of non- complex isolates and 6.5% azole-resistance rate amongst necessitates accurate species identification and susceptibility testing for optimal patient outcomes.
FUNDING
This work is unfunded. All authors' financial disclosures are listed in detail at the end of the manuscript.
PubMed: 37701716
DOI: 10.1016/j.lanwpc.2023.100888 -
Future Microbiology Dec 2023(shortened to ) is a fungus (plural: fungi) that can cause a serious infection in some people. can become resistant to medicines known as azoles (isavuconazole,... (Review)
Review
WHAT IS THIS SUMMARY ABOUT?
(shortened to ) is a fungus (plural: fungi) that can cause a serious infection in some people. can become resistant to medicines known as azoles (isavuconazole, itraconazole, posaconazole, and voriconazole). This means they stop working and are not able to kill the fungus. Fungi can become resistant through changes in their genes, which are called mutations. Scientists looked at previously collected samples from people infected with and found that 36 of the samples showed resistance to an azole. In 35 of these samples, scientists looked for mutations in 50 genes. These 50 genes are known to play a role in azole resistance and/or are important for fungal survival.
WHAT WERE THE RESULTS?
In total, 18 out of 36 samples (50%) showed resistance to isavuconazole only. Of these, 12 had mutations in 4 genes important for fungal survival (called , , and ). Mutations were found in 2 genes that are the most common causes of azole resistance (called and ). The most common mutation, called TR34/L98H, was found in 9 samples. Of these, 8 samples showed resistance to all 4 of the azoles tested.
WHAT DO THE RESULTS OF THE STUDY MEAN?
Studying mutations that make fungi resistant to medicines helps to make sure that people with fungal infections get treated with medicines that will work for them.
Topics: Humans; Antifungal Agents; Fungal Proteins; Aspergillus fumigatus; Azoles; Drug Resistance, Fungal; Microbial Sensitivity Tests
PubMed: 37920995
DOI: 10.2217/fmb-2023-0023 -
Veterinary World Aug 2023Several strains of produce mycotoxins that affect the health and productivity of dairy cattle, and their presence in dairy cattle feed is a serious concern. This study...
BACKGROUND AND AIM
Several strains of produce mycotoxins that affect the health and productivity of dairy cattle, and their presence in dairy cattle feed is a serious concern. This study aimed to determine the densities of and gliotoxin in commercial dairy feed.
MATERIALS AND METHODS
More than 60 dairy feed samples were examined for fungal contamination, specifically for , using phenotypic approaches and DNA sequencing of the () and β-tubulin regions. Thin-layer chromatography and high-performance liquid chromatography (HPLC) were used to assess gliotoxin production in . Real-time polymerase chain reaction (RT-PCR) was used to investigate the expression of Z, which was responsible for gliotoxin production. High-performance liquid chromatography was used to detect gliotoxin in feed samples.
RESULTS
was the most commonly identified genus (68.3%). was isolated from 18.3% of dairy feed samples. Only four of the 11 isolates yielded detectable gliotoxins by HPLC. In total, 7/11 (43.7%) feed samples tested had gliotoxin contamination above the threshold known to induce immunosuppressive and apoptotic effects . The HPLC-based classification of isolates as high, moderate, or non-producers of gliotoxin was confirmed by RT-PCR, and the evaluation of Z expression levels corroborated this classification.
CONCLUSION
The identification of from animal feed greatly depended on and β-tubulin sequencing. Significant concentrations of gliotoxin were found in dairy cattle feed, and its presence may affect dairy cow productivity and health. Furthermore, workers face contamination risks when handling and storing animal feed.
PubMed: 37766716
DOI: 10.14202/vetworld.2023.1636-1646 -
Microbiology Spectrum Sep 2023Several P-type ATPases are important Cd/Cu pumps in species, and they are tightly associated with the heavy metal stress tolerance of these ascomycetous fungi. To...
Several P-type ATPases are important Cd/Cu pumps in species, and they are tightly associated with the heavy metal stress tolerance of these ascomycetous fungi. To better understand the roles of the two P-type ATPases, CrpA Cd/Cu pump (orthologue of the Cd/Cu pump) and PcaA Cd pump (orthologue of the Pca1 Cd pump), we have generated individual mutants and characterized their heavy metal susceptibilities. The deletion of CrpA in has led to the increased sensitivity of the fungus to stresses induced by Zn, Fe, or the combination of oxidative-stress-inducing menadione sodium bisulfite and Fe. Heterologous expression of PcaA in the deletion mutant has resulted in enhanced tolerance of the yeast to stresses elicited by Cdor Zn but not by Fe/Fe or Cu. Mammalian host immune defense can attack microbes by secreting Zn or Cu, and the oxidative stress induced by host immune systems can also disturb metal (Cu, Fe, and Zn) homeostasis in microbes. In summary, PcaA and CrpA can protect fungal cells from these complex stresses that contribute to the virulence of the pathogenic species. Moreover, due to their presence on the fungal cell surface, these P-type ATPases may serve as a novel drug target in the future. IMPORTANCE Mammalian host immune defense disrupts heavy metal homeostasis of fungal pathogens. P1B-type ATPase of and may help to cope with this stress and serve as virulence traits. In our experiments, both Cd2+/Cu2+ pump CrpA and Cd2+ pump PcaA protected fungal cells from toxic Zn2+, and CrpA also decreased Fe2+ susceptibility most likely indirectly. In addition, CrpA protected cells against the combined stress induced by the oxidative stressor menadione and Fe3+. Since P1B-type ATPases are present on the fungal cell surface, these proteins may serve as a novel drug target in the future.
PubMed: 37676031
DOI: 10.1128/spectrum.00283-23