Aspergillosis In Immunocompromised Patients Research Articles

Increased Risk of Invasive Aspergillosis in Immunocompromised Patients With Persistent SARS-CoV-2 Viral Shedding >8 Weeks, Retrospective Case-control Study.

Immunocompromised patients now represent the population most at risk for severe coronavirus disease 2019. Persistent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral shedding was reported in these patients ranging from several weeks up to 9 months. We conducted a bicentric retrospective case-control study to identify risk and prognostic factors associated with persistent viral shedding in immunocompromised patients. Symptomatic immunocompromised adults with persistent SARS-CoV-2 viral shedding >8 weeks were retrospectively included between 1 March 2020 and 24 April 2022 at 2 university hospitals in Paris, France, and matched with a control group consisting of symptomatic immunocompromised patients without persistent viral shedding. Twenty-nine immunocompromised patients with persistent viral shedding were compared with 40 controls. In multivariate analysis, fever and lymphocytopenia (<0.5 G/L) were associated with an increased risk of persistent viral shedding (odds ratio [OR]: 3.3; 95% confidence interval [CI], 1.01-11.09) P = .048 and OR: 4.3; 95% CI, 1.2-14.7; P = .019, respectively). Unvaccinated patients had a 6-fold increased risk of persistent viral shedding (OR, 6.6; 95% CI, 1.7-25.1; P = .006). Patients with persistent viral shedding were at risk of hospitalization (OR: 4.8; 95 CI, 1.5-15.6; P = .008), invasive aspergillosis (OR: 10.17; 95 CI, 1.15-89.8; P = .037) and death (log-rank test <0.01). Vaccine coverage was protective against SARS-CoV-2 persistent viral shedding in immunocompromised patients. This new group of immunocompromised patients with SARS-CoV-2 persistent viral shedding is at risk of developing invasive aspergillosis and death and should therefore be systematically screened for this fungal infection for as long as the viral shedding persists.

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 Aspergillus 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 Aspergillus 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.

A heterologous expression platform in Aspergillus nidulans for the elucidation of cryptic secondary metabolism biosynthetic gene clusters: discovery of the Aspergillus fumigatus sartorypyrone biosynthetic pathway.

Aspergillus fumigatus is a serious human pathogen causing life-threatening Aspergillosis in immunocompromised patients. Secondary metabolites (SMs) play an important role in pathogenesis, but the products of many SM biosynthetic gene clusters (BGCs) remain unknown. In this study, we have developed a heterologous expression platform in Aspergillus nidulans, using a newly created genetic dereplication strain, to express a previously unknown BGC from A. fumigatus and determine its products. The BGC produces sartorypyrones, and we have named it the spy BGC. Analysis of targeted gene deletions by HRESIMS, NMR, and microcrystal electron diffraction (MicroED) enabled us to identify 12 products from the spy BGC. Seven of the compounds have not been isolated previously. We also individually expressed the polyketide synthase (PKS) gene spyA and demonstrated that it produces the polyketide triacetic acid lactone (TAL), a potentially important biorenewable platform chemical. Our data have allowed us to propose a biosynthetic pathway for sartorypyrones and related natural products. This work highlights the potential of using the A. nidulans heterologous expression platform to uncover cryptic BGCs from A. fumigatus and other species, despite the complexity of their secondary metabolomes.

Fungal Zinc Homeostasis and Its Potential as an Antifungal Target: A Focus on the Human Pathogen Aspergillus fumigatus.

Aspergillus fumigatus is an opportunistic airborne fungus that causes severe invasive aspergillosis in immunocompromised patients. Zinc is an essential micronutrient for the growth of A. fumigatus and even for all microorganisms. An increasing number of studies have reported that fungal zinc acquisition ability plays a key role in fungal survival in hosts with an extremely zinc-limited microenvironment. The ability to fight scarcity and excess of zinc are tightly related to fungal virulence and may be used as new potential targets. Because the regulation of zinc homeostasis is important, a thorough understanding of the functional genes involved in the regulatory network for zinc homeostasis is required for fungal pathogens. The current mini-review summarized potential zinc homeostasis regulators in A. fumigatus and classified these regulators according to localization and function, which were identified or predicted based on A. fumigatus or deduced from homologs in model yeasts. Future perspectives for zinc homeostasis regulators as potential antifungal targets to treat invasive aspergillosis are also discussed.

Role of biomarkers in the diagnosis of invasive aspergillosis in immunocompromised patients

BackgroundInvasive aspergillosis is one of the important causes of infection in immunocompromised patients. This study aimed to evaluate the roles of biomarkers in the diagnosis of invasive aspergillosis and their relationship with antifungal stewardship programs.Methods190 sera from 52 immunocompromised patients and volunteer individuals were included in this study. 18 immunocompromised volunteers without IA and 34 patients with probable and proven aspergillosis according to the European Organization for Research and Treatment of Cancer and the Mycoses Study Group consensus definitions were entered in this study. The respective sera were evaluated for procalcitonin, soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) levels; white blood cells count (WBC) count, C reactive protein (CRP), lactate dehydrogenase (LDH), and erythrocyte sedimentation rate (ESR) values. Demographic data and clinical characteristics of patients were extracted from their files.ResultsThe male-to-female ratio and mean age of patients were 22/12 and 38.9 years, respectively. The hematologic disorder was the most predisposing factor (29/34, 85.3%). Sensitivity of biomarkers for diagnosis of invasive aspergillosis was 70.6% (cut off value > 190 pg/mL for sTREM-1, 71% (cut off value > 260 pg/mL) for PCT, 85.3% (cut off value > 193 U/L) for LDH, 94.1% (cut off value > 8 mg/l) for CRP, 64.7% (cut off value < 5200 cells/ml) for WBC, and 85.3% (cut off value > 23 mm/h) for ESR. Twelve patients died, with significantly increased sTREM-1 levels and decreased WBC count in them.ConclusionAccording to our data, evaluation of the biomarkers can help in the diagnosis, management, and prediction of the severity of Aspergillus infection, and the rational use of antifungal agents in immunocompromised patients.

Life-Threatening Sinonasal Invasive Aspergillosis Easily Misdiagnosed

Background and Objectives Invasive fungal sinusitis is extremely rare. Yet the consequences of this infection may be fatal if not diagnosed correctly at an early stage. We discuss three cases of Aspergillosis sphenoid sinusitis that were misdiagnosed and have led to fatal consequences.Subjects and Method This is a retrospective analysis of cases diagnosed as invasive fungal sinusitis of sphenoid sinus.Results All three cases were of men who had immunocompromised medical histories that included leukemia and diabetes mellitus. The patients presented symptoms that included fever, chronic headache, weakness on one side, and facial edema. In the first case, CT showed no suspicious lesions that indicated fungal infection. However, five days after being prescribed antibiotics, the patient suffered obstruction of the right internal carotid artery (ICA) and right cavernous sinus. In the second case, CT showed total obstruction in the left ICA and a soft tissue mass in the left sphenoid sinus that extended and involved the left cavernous sinus. In the last case, CT showed soft density progression in the right sphenoid sinus with bone erosion when compared to images taken eight days earlier. In each of these cases, we performed emergency endoscopic sinus surgery. One case was confirmed to be invasive aspergillosis by histology whereas the other two cases were suspected to be invasive aspergillosis based on their past medical histories, clinical findings and image studies.Conclusion Clinicians must take great care to rule out invasive aspergillosis in immunocompromised patients with sinusitis.

Phosphomannose Isomerase Is Involved in Development, Stress Responses, and Pathogenicity of Aspergillus flavus.

ABSTRACTAspergillus flavus causes invasive aspergillosis in immunocompromised patients and severe contamination of agriculturally important crops by producing aflatoxins. The fungal cell wall is absent in animals and is structurally different from that of plants, which makes it a potential antifungal drug target due to its essentiality for fungal survival. Mannose is one of the important components in the fungal cell wall, which requires GDP-mannose (GDP-Man) as the primary donor. Three consecutive enzymes, namely, phosphomannose isomerase (PMI), phosphomannose mutase (PMM), and GDP-mannose phosphorylase (GMPP), are required for GDP-Man biosynthesis. Thus, PMI is of prime importance in cell wall biosynthesis and also has an active role in sugar metabolism. Here, we investigated the functional role of PMI in A. flavus by generating a pmiA-deficient strain. The mutant required exogenous mannose to survive and exhibited reduced growth rate, impaired conidiation, early germination, disturbance in stress responses, and defects in colonization of crop seeds. Furthermore, attenuated virulence of the mutant was documented in both Caenorhabditis elegans and Galleria mellonella infection models. Our results suggested that PMI plays an important role in the development, stress responses, and pathogenicity of A. flavus and therefore could serve as a potential target for battling against infection and controlling aflatoxin contamination caused by A. flavus.IMPORTANCE Aspergillus flavus is a common fungal pathogen of humans, animals, and agriculturally important crops. It causes invasive aspergillosis in humans and also produces highly carcinogenic mycotoxins in postharvest crops that threaten food safety worldwide. To alleviate or eliminate the threats posed by A. flavus, it is necessary to identify genes involved in pathogenicity and mycotoxin contamination. However, little progress has been made in this regard. Here, we focused on PMI, which is the first enzyme involved in the biosynthesis pathway of GDP-Man and thus is important for cell wall synthesis and protein glycosylation. Our study revealed that PMI is important for growth of A. flavus. It is also involved in conidiation, germination, morphogenesis, stress responses, and pathogenicity of A. flavus. Thus, PMI is a potent antifungal target to curb the threats posed by A. flavus.

Phosphoglucose Isomerase Plays a Key Role in Sugar Homeostasis, Stress Response, and Pathogenicity in Aspergillus flavus

Aspergillus flavus is one of the important human and plant pathogens causing not only invasive aspergillosis in immunocompromised patients but also crop contamination resulting from carcinogenic aflatoxins (AFs). Investigation of the targeting factors that are involved in pathogenicity is of unmet need to dismiss the hazard. Phosphoglucose isomerase (PGI) catalyzes the reversible conversion between glucose-6-phosphate and fructose-6-phosphate, thus acting as a key node for glycolysis, pentose phosphate pathway, and cell wall biosynthesis in fungi. In this study, we constructed an A. flavus pgi deletion mutant, which exhibited specific carbon requirement for survival, reduced conidiation, and slowed germination even under optimal experimental conditions. The Δpgi mutant lost the ability to form sclerotium and displayed hypersusceptibility to osmotic, oxidative, and temperature stresses. Furthermore, significant attenuated virulence of the Δpgi mutant was documented in the Caenorhabditis elegans infection model, Galleria mellonella larval model, and crop seeds. Our results indicate that PGI in A. flavus is a key enzyme in maintaining sugar homeostasis, stress response, and pathogenicity of A. flavus. Therefore, PGI is a potential target for controlling infection and AF contamination caused by A. flavus.

Chromosome assembled and annotated genome sequence of Aspergillus flavus NRRL 3357.

Aspergillus flavus is an opportunistic pathogen of crops, including peanuts and maize, and is the second leading cause of aspergillosis in immunocompromised patients. A. flavus is also a major producer of the mycotoxin, aflatoxin, a potent carcinogen, which results in significant crop losses annually. The A. flavus isolate NRRL 3357 was originally isolated from peanut and has been used as a model organism for understanding the regulation and production of secondary metabolites, such as aflatoxin. A draft genome of NRRL 3357 was previously constructed, enabling the development of molecular tools and for understanding population biology of this particular species. Here, we describe an updated, near complete, telomere-to-telomere assembly and re-annotation of the eight chromosomes of A. flavus NRRL 3357 genome, accomplished via long-read PacBio and Oxford Nanopore technologies combined with Illumina short-read sequencing. A total of 13,715 protein-coding genes were predicted. Using RNA-seq data, a significant improvement was achieved in predicted 5’ and 3’ untranslated regions, which were incorporated into the new gene models.

Genetic Interactions Between Aspergillus fumigatus Basic Leucine Zipper (bZIP) Transcription Factors AtfA, AtfB, AtfC, and AtfD.

Aspergillus fumigatus is an opportunistic fungus, capable of causing Invasive Aspergillosis in immunocompromised patients, recently transplanted or undergoing chemotherapy. In the present work, we continued the investigation on A. fumigatus AtfA-D transcription factors (TFs) characterizing possible genetic and physical interactions between them after normal growth and stressing conditions. We constructed double null mutants for all the possible combinations of ΔatfA-, -B, -C, and -D, and look into their susceptibility to different stressing conditions. Our results indicate complex genetic interactions among these TFs that could impact the response to different kinds of stressful conditions. AtfA-D interactions also affect the A. fumigatus virulence in Galleria mellonella. AtfA:GFP is ~97% located in the nucleus while about 20-30% of AtfB, -C, and -D:GFP locate into the nucleus in the absence of any stress. Under stressing conditions, AtfB, -C, and -D:GFP translocate to the nucleus about 60-80% upon the addition of sorbitol or H2O2. These four TFs are also interacting physically forming all the possible combinations of heterodimers. We also identified that AtfA-D physically interact with the MAPK SakA in the absence of any stress and upon osmotic and cell wall stresses. They are involved in the accumulation of trehalose, glycogen and metabolic assimilation of different carbon sources.

Galactomannan Produced by Aspergillus fumigatus: An Update on the Structure, Biosynthesis and Biological Functions of an Emblematic Fungal Biomarker.

The galactomannan (GM) that is produced by the human fungal pathogen Aspergillus fumigatus is an emblematic biomarker in medical mycology. The GM is composed of two monosaccharides: mannose and galactofuranose. The furanic configuration of galactose residues, absent in mammals, is responsible for the antigenicity of the GM and has favoured the development of ELISA tests to diagnose aspergillosis in immunocompromised patients. The GM that is produced by A. fumigatus is a unique fungal polysaccharide containing a tetramannoside repeat unit and having three different forms: (i) membrane bound through a glycosylphosphatidylinositol (GPI)-anchor, (ii) covalently linked to β-1,3-glucans in the cell wall, or (iii) released in the culture medium as a free polymer. Recent studies have revealed the crucial role of the GM during vegetative and polarized fungal growth. This review highlights these recent data on its biosynthetic pathway and its biological functions during the saprophytic and pathogenic life of this opportunistic human fungal pathogen.

Performance evaluation of a new mobile air-treatment technology at-rest and under normal work conditions in a conventional hematology room

Invasive fungal infections incidence in patients with hematological malignancies is increasing. Air treatment remains an essential preventive measure. Guidelines state that high-risk patients should be housed in units equipped with High-Efficiency Particulate Air filtration. Mobile air-treatment devices may be considered as alternatives or as a complement to the ventilation system. We assessed the decontamination performances of a new mobile air-treatment device in a conventional hematology room. This device connected or not to a plenum combining Ultra-Low Particulate Air filtration and non-thermal catalysis process has been evaluated with or without healthcare activities (one sampling at-rest and triplicate samplings in activity). Environmental particulate, airborne and surface fungal and total mesophilic flora (TMF) samplings were performed with a total of 1800 min of particles counting, 144 air and 240 surface samplings. At-rest, both devices achieved a 2-log decrease of airborne particles, ISO 4 being the maximal particle class reached under the plenum. Whatever the healthcare activities and the location in the room, ISO 7 was the maximal particle class reached. TMF and fungal air contamination were lower during healthcare activities when the air portable cleaners were running. The bed was the area the least contaminated in the room. No differences were observed for surface contamination. This work provides arguments of the efficacy of a new mobile air-treatment device to decrease particle counts and airborne bioburden in real-life conditions. Studies have yet to be conducted to document the impact of these devices on the risk of invasive aspergillosis in immunocompromised patients.

Biotinylated Surfome Profiling Identifies Potential Biomarkers for Diagnosis and Therapy of Aspergillus fumigatus Infection.

Aspergillus fumigatus is one of the most common airborne molds capable of causing mycoses and allergies in humans. During infection, fungal surface proteins mediate the first contact with the human immune system to evade immune responses or to induce hypersensitivity. Several methods have been established for surface proteomics (surfomics). Biotinylation coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) identification of peptides is a particularly efficient method to identify the surface-exposed regions of proteins that potentially mediate interaction with the host. After biotinylation of surface proteins during spore germination, we detected 231 different biotinylated surface proteins (including several well-known proteins such as RodA, CcpA, and DppV; allergens; and heat shock proteins [HSPs]), as well as some previously undescribed surface proteins. The dynamic change of the surface proteome was illustrated by detection of a relatively high number of proteins exclusively at one developmental stage. Using immunofluorescence microscopy, we confirmed the surface localization of several HSPs of the HSP70 family, which may have moonlighting functions. Collectively, by comparing our data with data representative of previously published A. fumigatus surface proteomes, our study generated a comprehensive data set corresponding to the A. fumigatus surfome and uncovered the surface-exposed regions of many proteins on the surface of conidia or hyphae. These surface-exposed regions are candidates for direct interaction with host cells and may represent antigenic epitopes that either induce protective immune responses or mediate immune evasion. Thus, our data sets provided and compiled here represent reasonable immunotherapy and diagnostic targets for future investigations.IMPORTANCEAspergillus fumigatus is the most important airborne human-pathogenic mold, capable of causing both life-threatening invasive pulmonary aspergillosis in immunocompromised patients and allergy-inducing infections in individuals with atopic allergy. Despite its obvious medical relevance, timely diagnosis and efficient antifungal treatment of A. fumigatus infection remain major challenges. Proteins on the surface of conidia (asexually produced spores) and mycelium directly mediate host-pathogen interaction and also may serve as targets for diagnosis and immunotherapy. However, the similarity of protein sequences between A. fumigatus and other organisms, sometimes even including the human host, makes selection of targets for immunological-based studies difficult. Here, using surface protein biotinylation coupled with LC-MS/MS analysis, we identified hundreds of A. fumigatus surface proteins with exposed regions, further defining putative targets for possible diagnostic and immunotherapeutic design.

Phosphoproteomics of Aspergillus fumigatus Exposed to the Antifungal Drug Caspofungin.

Aspergillus fumigatus is an opportunistic and allergenic pathogenic fungus, responsible for fungal infections in humans. A. fumigatus infections are usually treated with polyenes, azoles, or echinocandins. Echinocandins, such as caspofungin, can inhibit the biosynthesis of the β-1,3-glucan polysaccharide, affecting the integrity of the cell wall and leading to fungal death. In some A. fumigatus strains, caspofungin treatment at high concentrations induces an increase of fungal growth, a phenomenon called the caspofungin paradoxical effect (CPE). Here, we analyze the proteome and phosphoproteome of the A. fumigatus wild-type strain and of mitogen-activated protein kinase (MAPK) mpkA and sakA null mutant strains during CPE (2 μg/ml caspofungin for 1 h). The wild-type proteome showed 75 proteins and 814 phosphopeptides (corresponding to 520 proteins) altered in abundance in response to caspofungin treatment. The ΔmpkA (ΔmpkA caspofungin/wild-type caspofungin) and ΔsakA (ΔsakA caspofungin/wild-type caspofungin) strains displayed 626 proteins and 1,236 phosphopeptides (corresponding to 703 proteins) and 101 proteins and 1,217 phosphopeptides (corresponding to 645 proteins), respectively, altered in abundance. Functional characterization of the phosphopeptides from the wild-type strain exposed to caspofungin showed enrichment for transcription factors, protein kinases, and cytoskeleton proteins. Proteomic analysis of the ΔmpkA and ΔsakA mutants indicated that control of proteins involved in metabolism, such as in production of secondary metabolites, was highly represented in both mutants. Results of functional categorization of phosphopeptides from both mutants were very similar and showed a high number of proteins with decreased phosphorylation of proteins involved in transcriptional control, DNA/RNA binding, cell cycle control, and DNA processing. This report reveals novel transcription factors involved in caspofungin tolerance.IMPORTANCEAspergillus fumigatus is an opportunistic human-pathogenic fungus causing allergic reactions or systemic infections, such as invasive pulmonary aspergillosis in immunocompromised patients. Caspofungin is an echinocandin that impacts the construction of the fungal cell wall by inhibiting the biosynthesis of the β-1,3-glucan polysaccharide. Caspofungin is a fungistatic drug and is recommended as a second-line therapy for treatment of aspergillosis. Treatment at high concentrations induces an increase of fungal growth, a phenomenon called the caspofungin paradoxical effect (CPE). Collaboration between the mitogen-activated protein kinases (MAPK) of the cell wall integrity (MapkA) and high-osmolarity glycerol (SakA) pathways is essential for CPE. Here, we investigate the global proteome and phosphoproteome of A. fumigatus wild-type, ΔmpkA, and ΔsakA strains upon CPE. This study showed intense cross talk between the two MAPKs for the CPE and identified novel protein kinases and transcription factors possibly important for CPE. Increased understanding of how the modulation of protein phosphorylation may affect the fungal growth in the presence of caspofungin represents an important step in the development of new strategies and methods to combat the fungus inside the host.

The Aspergillus fumigatus Phosphoproteome Reveals Roles of High-Osmolarity Glycerol Mitogen-Activated Protein Kinases in Promoting Cell Wall Damage and Caspofungin Tolerance.

The filamentous fungus Aspergillus fumigatus can cause a distinct set of clinical disorders in humans. Invasive aspergillosis (IA) is the most common life-threatening fungal disease of immunocompromised humans. The mitogen-activated protein kinase (MAPK) signaling pathways are essential to the adaptation to the human host. Fungal cell survival is highly dependent on the organization, composition, and function of the cell wall. Here, an evaluation of the global A. fumigatus phosphoproteome under cell wall stress caused by the cell wall-damaging agent Congo red (CR) revealed 485 proteins potentially involved in the cell wall damage response. Comparative phosphoproteome analyses with the ΔsakA, ΔmpkC, and ΔsakA ΔmpkC mutant strains from the osmotic stress MAPK cascades identify their additional roles during the cell wall stress response. Our phosphoproteomics allowed the identification of novel kinases and transcription factors (TFs) involved in osmotic stress and in the cell wall integrity (CWI) pathway. Our global phosphoproteome network analysis showed an enrichment for protein kinases, RNA recognition motif domains, and the MAPK signaling pathway. In contrast to the wild-type strain, there is an overall decrease of differentially phosphorylated kinases and phosphatases in ΔsakA, ΔmpkC, and ΔsakA ΔmpkC mutants. We constructed phosphomutants for the phosphorylation sites of several proteins differentially phosphorylated in the wild-type and mutant strains. For all the phosphomutants, there is an increase in the sensitivity to cell wall-damaging agents and a reduction in the MpkA phosphorylation upon CR stress, suggesting these phosphosites could be important for the MpkA modulation and CWI pathway regulation.IMPORTANCEAspergillus fumigatus is an opportunistic human pathogen causing allergic reactions or systemic infections, such as invasive pulmonary aspergillosis in immunocompromised patients. The mitogen-activated protein kinase (MAPK) signaling pathways are essential for fungal adaptation to the human host. Fungal cell survival, fungicide tolerance, and virulence are highly dependent on the organization, composition, and function of the cell wall. Upon cell wall stress, MAPKs phosphorylate multiple target proteins involved in the remodeling of the cell wall. Here, we investigate the global phosphoproteome of the ΔsakA and ΔmpkCA. fumigatus and high-osmolarity glycerol (HOG) pathway MAPK mutants upon cell wall damage. This showed the involvement of the HOG pathway and identified novel protein kinases and transcription factors, which were confirmed by fungal genetics to be involved in promoting tolerance of cell wall damage. Our results provide understanding of how fungal signal transduction networks modulate the cell wall. This may also lead to the discovery of new fungicide drug targets to impact fungal cell wall function, fungicide tolerance, and virulence.

Prophylaxis and Treatment of Invasive Aspergillosis: Who and How of Prophylaxis, Treatment, and New Therapies

To discuss the approach to antifungal prophylaxis and treatment for invasive aspergillosis in immunocompromised patients with hematologic malignancies, hematopoietic stem cell transplant, and solid organ transplant recipients. Primary prophylaxis against Aspergillus is recommended for patients with acute myelogenous leukemia receiving remission-induction chemotherapy. Posaconazole or voriconazole are appropriate antifungal agents. A new formulation of itraconazole (SUBA-itraconazole) is an alternative option. Breakthrough infections on isavuconazole prophylaxis have been recently reported. For liver transplant recipients, targeted prophylaxis is recommended in the presence of certain risk factors. Voriconazole and isavuconazole are the preferred agents for the treatment of invasive aspergillosis. Isavuconazole, a novel extended-spectrum triazole with activity against Aspergillus and Mucorales, was found to be non-inferior compared to voriconazole. Combination of voriconazole with an echinocandin is generally not recommended. Reduction in immunosuppression is recommended as part of the management of invasive aspergillosis. The adjunctive use of interferon-γ may be considered in patients with severe or refractory disease, although a benefit has not been clearly demonstrated. The approach to prevention and treatment of invasive aspergillosis has evolved along with changes in immunosuppressive treatment and introduction of novel antifungal agents.

Demolition activities in a healthcare facility: results from a fungal surveillance after extraordinary preventive measures

ObjectivesAspergillus spp could be responsible of nosocomial aspergillosis in immunocompromised patients. In 2018, it was decided to demolish a building of Careggi Hospital (Florence, Italy), the Chief Medical Officer ordered a 9-months-long air and surface microbiological sampling and extraordinary preventive measures. Study designA 9-months-long prospective study. MethodsAfter mapping the at-risk areas, air and surface samples were collected in different locations: in corridors, in rooms (high efficiency particulate air filter (HEPA) filtered or not), and outdoors. The samples were collected during the critical phases of the demolition. Air temperature and weather conditions were determined and recorded at the beginning of each sampling. ResultsSeventy-eight air samples and 72 surface samples were collected. The results showed highest contamination at time zero (before extraordinary preventive measures) and in the wards without HEPA filtered air. No specific prophylaxis strategy was implemented at our hospital for immunocompromised patients, and no cases of aspergillosis were recorded. ConclusionsOur results showed that extraordinary protective measures, the use of air treatment systems, and a continuous monitoring could be associated with decreased Aspergillus air contamination during construction, renovation, or demolition works.

Invasive Aspergillosis by Aspergillus flavus: Epidemiology, Diagnosis, Antifungal Resistance, and Management.

Aspergillus flavus is the second most common etiological agent of invasive aspergillosis (IA) after A. fumigatus. However, most literature describes IA in relation to A. fumigatus or together with other Aspergillus species. Certain differences exist in IA caused by A. flavus and A. fumigatus and studies on A. flavus infections are increasing. Hence, we performed a comprehensive updated review on IA due to A. flavus. A. flavus is the cause of a broad spectrum of human diseases predominantly in Asia, the Middle East, and Africa possibly due to its ability to survive better in hot and arid climatic conditions compared to other Aspergillus spp. Worldwide, ~10% of cases of bronchopulmonary aspergillosis are caused by A. flavus. Outbreaks have usually been associated with construction activities as invasive pulmonary aspergillosis in immunocompromised patients and cutaneous, subcutaneous, and mucosal forms in immunocompetent individuals. Multilocus microsatellite typing is well standardized to differentiate A. flavus isolates into different clades. A. flavus is intrinsically resistant to polyenes. In contrast to A. fumigatus, triazole resistance infrequently occurs in A. flavus and is associated with mutations in the cyp51C gene. Overexpression of efflux pumps in non-wildtype strains lacking mutations in the cyp51 gene can also lead to high voriconazole minimum inhibitory concentrations. Voriconazole remains the drug of choice for treatment, and amphotericin B should be avoided. Primary therapy with echinocandins is not the first choice but the combination with voriconazole or as monotherapy may be used when the azoles and amphotericin B are contraindicated.

Galactomannan detection in broncho-alveolar lavage fluid for invasive aspergillosis in immunocompromised patients.

Invasive aspergillosis (IA) is a life-threatening opportunistic mycosis that occurs in some people with a compromised immune system. The serum galactomannan enzyme-linked immunosorbent assay (ELISA) rapidly gained widespread acceptance as part of the diagnostic work-up of a patient suspected of IA. Due to its non-invasive nature, it can be used as a routine screening test. The ELISA can also be performed on bronchoalveolar lavage (BAL), allowing sampling of the immediate vicinity of the infection. The invasive nature of acquiring BAL, however, changes the role of the galactomannan test significantly, for example by precluding its use as a routine screening test. To assess the diagnostic accuracy of galactomannan detection in BAL for the diagnosis of IA in people who are immunocompromised, at different cut-off values for test positivity, in accordance with the Cochrane Diagnostic Test Accuracy Handbook. We searched three bibliographic databases including MEDLINE on 9 September 2016 for aspergillosis and galactomannan as text words and subject headings where appropriate. We checked reference lists of included studies for additional studies. We included cohort studies that examined the accuracy of BAL galactomannan for the diagnosis of IA in immunocompromised patients if they used the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) classification as reference standard. Two review authors assessed study quality and extracted data. Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used for quality assessment. We included 17 studies in our review. All studies except one had a high risk of bias in two or more domains. The diagnostic performance of an optical density index (ODI) of 0.5 as cut-off value was reported in 12 studies (with 1123 patients). The estimated sensitivity was 0.88 (95% confidence interval (CI) 0.75 to 1.00) and specificity 0.81 (95% CI 0.71 to 0.91). The performance of an ODI of 1.0 as cut-off value could be determined in 11 studies (with 648 patients). The sensitivity was 0.78 (95% CI 0.61 to 0.95) and specificity 0.93 (95% CI 0.87 to 0.98). At a cut-off ODI of 1.5 or higher, the heterogeneity in specificity decreased significantly and was invariably >90%. The optimal cut-off value depends on the local incidence and clinical pathway. At a prevalence of 12% a hypothetical population of 1000 patients will consist of 120 patients with IA. At a cut-off value of 0.5 14 patients with IA will be missed and there will be 167 patients incorrectly diagnosed with IA. If we use the test at a cut-off value of 1.0, we will miss 26 patients with IA. And there will be 62 patients incorrectly diagnosed with invasive aspergillosis. The populations and results were very heterogeneous. Therefore, interpretation and extrapolation of these results has to be performed with caution. A test result of 1.5 ODI or higher appears a strong indicator of IA.

Diagnostic role of polymerase chain reaction in bronchoalveolar lavage fluid for invasive pulmonary aspergillosis in immunocompromised patients – A retrospective cohort study

BackgroundThis study aimed to evaluate the diagnostic role of PCR detection of Aspergillus DNA in the broncho-alveolar lavage (BAL) fluid in a large cohort of patients suspected to have invasive pulmonary aspergillosis (IPA). MethodsConsecutive immunocompromised patients who underwent bronchoscopy with BAL sampling and PCR detection of Aspergillus DNA for the diagnosis of pulmonary infiltrates were included in the study. Galactomannan (GM) antigen testing in BAL and serum and BAL fungal culture were also performed. Patients were classified as having IPA (proven/probable/possible) or no-IPA according to the EORTC/MSG diagnostic criteria. ResultsDuring 12 years (2005–2016), 1248 bronchoscopies were performed for 1072 patients. 77% had hematological malignancy, of them 40% had AML and 35.6% underwent HSCT. IPA was diagnosed in 531 patients (42.5%), 7-proven, 280-probable and 244-possible. PCR was positive in 266 cases, of them 213 had IPA, indicating a true positive rate of 80% (213/266) and a false positive rate of 20% (53/266). These results establish the diagnostic performance of PCR to have sensitivity of 40%, specificity of 93%, PPV- 80% and NPV-68%. Of 244 patients with possible IPA, 80 had positive PCR. Including PCR in the diagnostic criteria would move 80 cases from the possible group to the probable one. A combination of positive PCR and/or BAL-GM increases sensitivity to 74%, while positivity of both tests elevates PPV to 99.4%. ConclusionsInclusion PCR for the detection of Aspergillus-DNA in BAL in the mycological criteria of the EORTC/MSG definitions increases the rate and the certainty of IPA diagnosis.