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1.
PLoS Pathog ; 20(4): e1012154, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38603707

RESUMO

Candida albicans chronically colonizes the respiratory tract of patients with Cystic Fibrosis (CF). It competes with CF-associated pathogens (e.g. Pseudomonas aeruginosa) and contributes to disease severity. We hypothesize that C. albicans undergoes specific adaptation mechanisms that explain its persistence in the CF lung environment. To identify the underlying genetic and phenotypic determinants, we serially recovered 146 C. albicans clinical isolates over a period of 30 months from the sputum of 25 antifungal-naive CF patients. Multilocus sequence typing analyses revealed that most patients were individually colonized with genetically close strains, facilitating comparative analyses between serial isolates. We strikingly observed differential ability to filament and form monospecies and dual-species biofilms with P. aeruginosa among 18 serial isolates sharing the same diploid sequence type, recovered within one year from a pediatric patient. Whole genome sequencing revealed that their genomes were highly heterozygous and similar to each other, displaying a highly clonal subpopulation structure. Data mining identified 34 non-synonymous heterozygous SNPs in 19 open reading frames differentiating the hyperfilamentous and strong biofilm-former strains from the remaining isolates. Among these, we detected a glycine-to-glutamate substitution at position 299 (G299E) in the deduced amino acid sequence of the zinc cluster transcription factor ROB1 (ROB1G299E), encoding a major regulator of filamentous growth and biofilm formation. Introduction of the G299E heterozygous mutation in a co-isolated weak biofilm-former CF strain was sufficient to confer hyperfilamentous growth, increased expression of hyphal-specific genes, increased monospecies biofilm formation and increased survival in dual-species biofilms formed with P. aeruginosa, indicating that ROB1G299E is a gain-of-function mutation. Disruption of ROB1 in a hyperfilamentous isolate carrying the ROB1G299E allele abolished hyperfilamentation and biofilm formation. Our study links a single heterozygous mutation to the ability of C. albicans to better survive during the interaction with other CF-associated microbes and illuminates how adaptive traits emerge in microbial pathogens to persistently colonize and/or infect the CF-patient airways.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38556212

RESUMO

OBJECTIVES: We aimed to describe features and outcomes of cryptococcosis among HIV-seronegative individuals in a large surveillance network for cryptococcosis in France. METHODS: We included incident cases of cryptococcosis in HIV-seronegative individuals from 2005 to 2020. We compared patient characteristics, disease presentations, cryptococcal antigen results, and induction antifungal treatments according to underlying disease. We examined factors associated with 90-day mortality. Among patients with disseminated infections, we investigated whether receipt of flucytosine and polyene combination was associated with lower mortality. RESULTS: Among 652 individuals, 209 (32.1%) had malignancy, 130 (19.9%) were solid-organ transplant recipients, 204 (31.3%) had other immunocompromising conditions, and 109 (16.7%) had no reported underlying factor. The commonest presentations were disseminated infections (63.3%, 413/652) and isolated pulmonary infections (25.3%, 165/652). Solid-organ transplant patients were most likely to have disseminated infections and a positive serum cryptococcal antigen result. Patients with malignancy were older and less likely to receive a flucytosine-containing regimen for disseminated infections than others (58.7%, 78/133 vs. 73.2%, 194/265; p 0.029). The crude 90-day case-fatality ratio was 27.2% (95% CI, 23.5%-31.1%). Age ≥60 years (aOR: 2.75 [1.78-4.26]; p < 0.001), meningitis/fungaemia (aOR: 4.79 [1.80-12.7]; p 0.002), and malignancy (aOR: 2.4 [1.14-5.07]; p 0.02) were associated with higher 90-day mortality. Receipt of flucytosine and polyene combination was associated with lower 90-day mortality (aOR: 0.40 [0.23-0.71]; p 0.002) in multivariable analysis and inverse probability of treatment weighted analysis (aOR: 0.45 [0.25-0.80]; p 0.006). DISCUSSION: HIV-seronegative individuals with cryptococcosis comprise a wide range of underlying conditions with different presentations and outcomes, requiring a tailored approach to diagnosis and management.

3.
Int J Infect Dis ; 142: 107000, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38461932

RESUMO

OBJECTIVES: Ibrutinib, a first-generation covalent Bruton's tyrosine kinase inhibitor (BTKi) was found to be a risk factor for the occurrence of invasive fungal complications. Acalabrutinib is a second-generation covalent BTKi used to treat B-cell malignancies. Healthy donor neutrophils incubated ex vivo with acalabrutinib lose ability to control Aspergillus conidia germination. In patients receiving acalabrutinib, the potential effect on neutrophil antifungal activity is unknown. Furthermore, only two cases of invasive aspergillosis have been reported during treatment with acalabrutinib, outside of a few cases in a clinical trial. METHODS: We describe three new cases of invasive aspergillosis occurring within the first months of acalabrutinib therapy in patients with chronic lymphocytic leukemia. We used videomicroscopy and flow cytometry approaches to investigate the basic functional responses against Aspergillus of neutrophils from acalabrutinib-treated patients. RESULTS: We showed an alteration in the anti-Aspergillus response after 1 month of acalabrutinb therapy: neutrophils lost their capacities of killing Aspergillus fumigatus germinating conidia and decreased their reactive oxygen species production when stimulated by Aspergillus. CONCLUSIONS: It is important to follow-up patients treated with acalabrutinib for the risk of aspergillosis as well as those treated with ibrutinib.


Assuntos
Aspergilose , Aspergillus fumigatus , Benzamidas , Pirazinas , Humanos , Tirosina Quinase da Agamaglobulinemia , Neutrófilos , Aspergilose/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico
4.
Microbiome ; 12(1): 50, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38468305

RESUMO

BACKGROUND: Antibiotics notoriously perturb the gut microbiota. We treated healthy volunteers either with cefotaxime or ceftriaxone for 3 days, and collected in each subject 12 faecal samples up to day 90. Using untargeted and targeted phenotypic and genotypic approaches, we studied the changes in the bacterial, phage and fungal components of the microbiota as well as the metabolome and the ß-lactamase activity of the stools. This allowed assessing their degrees of perturbation and resilience. RESULTS: While only two subjects had detectable concentrations of antibiotics in their faeces, suggesting important antibiotic degradation in the gut, the intravenous treatment perturbed very significantly the bacterial and phage microbiota, as well as the composition of the metabolome. In contrast, treatment impact was relatively low on the fungal microbiota. At the end of the surveillance period, we found evidence of resilience across the gut system since most components returned to a state like the initial one, even if the structure of the bacterial microbiota changed and the dynamics of the different components over time were rarely correlated. The observed richness of the antibiotic resistance genes repertoire was significantly reduced up to day 30, while a significant increase in the relative abundance of ß-lactamase encoding genes was observed up to day 10, consistent with a concomitant increase in the ß-lactamase activity of the microbiota. The level of ß-lactamase activity at baseline was positively associated with the resilience of the metabolome content of the stools. CONCLUSIONS: In healthy adults, antibiotics perturb many components of the microbiota, which return close to the baseline state within 30 days. These data suggest an important role of endogenous ß-lactamase-producing anaerobes in protecting the functions of the microbiota by de-activating the antibiotics reaching the colon. Video Abstract.


Assuntos
Microbioma Gastrointestinal , Resiliência Psicológica , Adulto , Humanos , Microbioma Gastrointestinal/genética , beta-Lactamases/genética , beta-Lactamas/farmacologia , Voluntários Saudáveis , Antibacterianos , Bactérias/genética , Fezes/microbiologia
5.
Open Forum Infect Dis ; 11(2): ofae012, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38390457

RESUMO

Background: 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. Material and Methods: 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. Results: 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). Conclusions: 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.

6.
Nat Microbiol ; 9(3): 669-683, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38388771

RESUMO

The opportunistic fungal pathogen Candida albicans damages host cells via its peptide toxin, candidalysin. Before secretion, candidalysin is embedded in a precursor protein, Ece1, which consists of a signal peptide, the precursor of candidalysin and seven non-candidalysin Ece1 peptides (NCEPs), and is found to be conserved in clinical isolates. Here we show that the Ece1 polyprotein does not resemble the usual precursor structure of peptide toxins. C. albicans cells are not susceptible to their own toxin, and single NCEPs adjacent to candidalysin are sufficient to prevent host cell toxicity. Using a series of Ece1 mutants, mass spectrometry and anti-candidalysin nanobodies, we show that NCEPs play a role in intracellular Ece1 folding and candidalysin secretion. Removal of single NCEPs or modifications of peptide sequences cause an unfolded protein response (UPR), which in turn inhibits hypha formation and pathogenicity in vitro. Our data indicate that the Ece1 precursor is not required to block premature pore-forming toxicity, but rather to prevent intracellular auto-aggregation of candidalysin sequences.


Assuntos
Proteínas Fúngicas , Micotoxinas , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Candida albicans/metabolismo , Micotoxinas/metabolismo , Peptídeos/farmacologia , Peptídeos/metabolismo
8.
mBio ; 15(2): e0189823, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38259065

RESUMO

Microbial species capable of co-existing with healthy individuals, such as the commensal fungus Candida albicans, exploit multifarious strategies to evade our immune defenses. These strategies include the masking of immunoinflammatory pathogen-associated molecular patterns (PAMPs) at their cell surface. We reported previously that C. albicans actively reduces the exposure of the proinflammatory PAMP, ß-1,3-glucan, at its cell surface in response to host-related signals such as lactate and hypoxia. Here, we show that clinical isolates of C. albicans display phenotypic variability with respect to their lactate- and hypoxia-induced ß-1,3-glucan masking. We have exploited this variability to identify responsive and non-responsive clinical isolates. We then performed RNA sequencing on these isolates to reveal genes whose expression patterns suggested potential association with lactate- or hypoxia-induced ß-1,3-glucan masking. The deletion of two such genes attenuated masking: PHO84 and NCE103. We examined NCE103-related signaling further because NCE103 has been shown previously to encode carbonic anhydrase, which promotes adenylyl cyclase-protein kinase A (PKA) signaling at low CO2 levels. We show that while CO2 does not trigger ß-1,3-glucan masking in C. albicans, the Sch9-Rca1-Nce103 signaling module strongly influences ß-1,3-glucan exposure in response to hypoxia and lactate. In addition to identifying a new regulatory module that controls PAMP exposure in C. albicans, our data imply that this module is important for PKA signaling in response to environmental inputs other than CO2.IMPORTANCEOur innate immune defenses have evolved to protect us against microbial infection in part via receptor-mediated detection of "pathogen-associated molecular patterns" (PAMPs) expressed by invading microbes, which then triggers their immune clearance. Despite this surveillance, many microbial species are able to colonize healthy, immune-competent individuals, without causing infection. To do so, these microbes must evade immunity. The commensal fungus Candida albicans exploits a variety of strategies to evade immunity, one of which involves reducing the exposure of a proinflammatory PAMP (ß-1,3-glucan) at its cell surface. Most of the ß-1,3-glucan is located in the inner layer of the C. albicans cell wall, hidden by an outer layer of mannan fibrils. Nevertheless, some ß-1,3-glucan can become exposed at the fungal cell surface. However, in response to certain specific host signals, such as lactate or hypoxia, C. albicans activates an anticipatory protective response that decreases ß-1,3-glucan exposure, thereby reducing the susceptibility of the fungus to impending innate immune attack. Here, we exploited the natural phenotypic variability of C. albicans clinical isolates to identify strains that do not display the response to ß-1,3-glucan masking signals observed for the reference isolate, SC5314. Then, using genome-wide transcriptional profiling, we compared these non-responsive isolates with responsive controls to identify genes potentially involved in ß-1,3-glucan masking. Mutational analysis of these genes revealed that a sensing module that was previously associated with CO2 sensing also modulates ß-1,3-glucan exposure in response to hypoxia and lactate in this major fungal pathogen of humans.


Assuntos
Candida albicans , Glucanos , beta-Glucanas , Humanos , Candida albicans/metabolismo , Glucanos/metabolismo , Dióxido de Carbono/metabolismo , Moléculas com Motivos Associados a Patógenos , Hipóxia/metabolismo , Lactatos/metabolismo , Parede Celular/metabolismo
9.
Med Mycol ; 62(2)2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38228404

RESUMO

Deep cutaneous mycoses (DCMs) are rare infections that extend throughout the dermis and subcutis, often occurring after inoculation with pathogenic fungi. Trends toward a growing incidence have been observed that may be partially related to an increasing population of solid organ transplant patients. The aim of this study is to describe the diagnostics and the outcomes of DCM among kidney transplant recipients so as to optimize their management. We performed a retrospective review of cases of DCM occurring among kidney transplant recipients in our institution over 12 years. Twenty cases were included. Lesions were only located on the limbs and presented mainly as single (10/20, 50%) nodular lesions (15/20, 75%), with a mean size of 3 cm. Direct mycological examination was positive for 17 patients (17/20, 85%) and the cultures were consistently positive. Thirteen different fungal species were observed, including phaehyphomycetes (n = 8), hyalohyphomycetes (n = 3), dermatophytes (n = 1), and mucorale (n = 1). The (1-3) beta-D-glucan antigen (BDG) was also consistently detected in the serum (20/20, 100%). Systematic imaging did not reveal any distant infectious lesions, but locoregional extension was present in 11 patients (11/14, 79%). Nineteen patients received antifungal treatment (19/20, 95%) for a median duration of 3 months, with surgery for 10 (10/20, 50%). There is a great diversity of fungal species responsible for DCMs in kidney transplant recipients. The mycological documentation is necessary to adapt the antifungal treatment according to the sensitivity of the species. Serum BDG positivity is a potentially reliable and useful tool for diagnosis and follow-up.


Assuntos
Dermatomicoses , Transplante de Rim , Transplante de Órgãos , Humanos , Antifúngicos/uso terapêutico , Transplante de Rim/efeitos adversos , Transplante de Rim/veterinária , Dermatomicoses/diagnóstico , Dermatomicoses/tratamento farmacológico , Dermatomicoses/veterinária , Transplante de Órgãos/veterinária , Pele/microbiologia , Transplantados
11.
Microbes Infect ; 26(1-2): 105230, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37734535

RESUMO

The Candida albicans population displays high genetic diversity illustrated by 18-well differentiated genetic clusters. Cluster 13, also known as Candida africana, is an outlying cluster and includes strains first described as atypical C. albicans isolates of vaginal origin, showing apparent tropism for the female genital tract. In our study, we combined in vitro, and in vivo models to explore the colonization and pathogenic potential of C. africana. We report that C. africana has similar fitness to C. albicans when it comes to colonization of the oral and vaginal mucosa, however it has decreased fitness in gastro-intestinal colonization and systemic infection. Interestingly, despite high population homogeneity, our in vitro data highlighted for the first time a variability in terms of growth rate, biofilm formation and filamentation properties between C. africana strains. Overall, our data lays the foundations for exploring specific features of C. africana that might contribute to its apparent niche restriction.


Assuntos
Candidíase Vulvovaginal , Feminino , Humanos , Candidíase Vulvovaginal/epidemiologia , Antifúngicos , Candida/genética , Candida albicans/genética
13.
Gut Microbes ; 15(2): 2287618, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38017705

RESUMO

Candida albicans is a commensal yeast present in the gut of most healthy individuals but with highly variable concentrations. However, little is known about the host factors that influence colonization densities. We investigated how microbiota, host lifestyle factors, and genetics could shape C. albicans intestinal carriage in 695 healthy individuals from the Milieu Intérieur cohort. C. albicans intestinal carriage was detected in 82.9% of the subjects using quantitative PCR. Using linear mixed models and multiway-ANOVA, we explored C. albicans intestinal levels with regard to gut microbiota composition and lifestyle factors including diet. By analyzing shotgun metagenomics data and C. albicans qPCR data, we showed that Intestinimonas butyriciproducens was the only gut microbiota species whose relative abundance was negatively correlated with C. albicans concentration. Diet is also linked to C. albicans growth, with eating between meals and a low-sodium diet being associated with higher C. albicans levels. Furthermore, by Genome-Wide Association Study, we identified 26 single nucleotide polymorphisms suggestively associated with C. albicans colonization. In addition, we found that the intestinal levels of C. albicans might influence the host immune response, specifically in response to fungal challenge. We analyzed the transcriptional levels of 546 immune genes and the concentration of 13 cytokines after whole blood stimulation with C. albicans cells and showed positive associations between the extent of C. albicans intestinal levels and NLRP3 expression, as well as secreted IL-2 and CXCL5 concentrations. Taken together, these findings open the way for potential new interventional strategies to curb C. albicans intestinal overgrowth.


Assuntos
Candida albicans , Microbioma Gastrointestinal , Humanos , Candida albicans/fisiologia , Estudo de Associação Genômica Ampla , Microbioma Gastrointestinal/fisiologia , Dieta , Imunidade
14.
Emerg Microbes Infect ; 12(2): 2258997, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37706342

RESUMO

Intestinal microsporidiosis is most often caused by Enterocytozoon bieneusi, and to a lesser extent by species of the genus Encephalitozoon. Until now, Encephalitozoon hellem was not clearly known to induce disease restricted to the intestine, or rarely in HIV subjects or in tropical countries. We report here 11 cases of delineated intestinal microsporidioses due to E. hellem diagnosed in France in non-HIV patients. Briefly, all patients were immunocompromised. They all suffered from diarrhoea, associated in nearly 50% of cases with weight loss. Concerning treatment, 5/11 patients had a discontinuation or a decrease of their immunosuppressive therapy, and 4/11 received albendazole. All patients recovered. Five different genotypes were identified based on the rRNA ITS sequence.


Assuntos
Encephalitozoon , Enterocytozoon , Microsporidiose , Humanos , Encephalitozoon/genética , Enterocytozoon/genética , Intestinos , Fezes
15.
RMD Open ; 9(3)2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37558492

RESUMO

OBJECTIVES: We aimed to describe patients with autoimmune diseases (AID) developing invasive fungal disease (IFD) and identify factors associated with short-term mortality. METHODS: We analysed cases of IFD associated with AID from the surveillance network of invasive fungal diseases (Réseau de surveillance des infections fongiques invasives, RESSIF) registry of the French national reference centre for invasive mycoses. We studied association of AID-specific treatments with 30-day mortality. We analysed total lymphocyte and CD4-T cell counts in patients with Pneumocystis jirovecii pneumonia (PCP). RESULTS: From 2012 to 2018, 549 individuals with IFD and AID were included, mainly with PCP (n=227, 41.3%), fungemia (n=167, 30.4%) and invasive aspergillosis (n=84, 15.5%). Rheumatoid arthritis (RA) and anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV) were the most frequent AID in PCP (n=55 and 25, respectively) and invasive aspergillosis (n=15 and 10, respectively), inflammatory bowel diseases (IBDs) were predominant in fungemia (n=36). At IFD diagnosis, 365 (66.5%) patients received glucocorticoids (GCs), 285 (51.9%) immunosuppressants, 42 (7.7%) tumor necrosis factor (TNF)-α blockers, 75 (13.7%) other biologics. Mortality at 30 days was 28.1% (143/508). Fungemia and high-dose GCs were independently associated with higher 30-day mortality. In PCP patients, lymphopenia <1500/mm3 was frequent (132/179, 73.7%) even if CD4+T cell count exceeded 200/mm3 in 56/78 patients (71.8%) (median 472.5/mm3, IQR 160-858). CONCLUSION: IFD associated with AID occurs primarily in RA, AAV and IBD, especially when treated with GCs and immunosuppressants. Mortality is high, especially for patients on high-dose GCs. Lymphopenia may help identify risk of PCP, but normal CD4+T cell count does not rule out the risk. Further studies are needed to assess the individual risk factors for IFD.


Assuntos
Doenças Autoimunes , Infecções Fúngicas Invasivas , Doenças Autoimunes/complicações , Doenças Autoimunes/terapia , Infecções Fúngicas Invasivas/complicações , Infecções Fúngicas Invasivas/epidemiologia , Infecções Fúngicas Invasivas/etiologia , Infecções Fúngicas Invasivas/mortalidade , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Glucocorticoides/efeitos adversos , Glucocorticoides/uso terapêutico , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Fatores de Risco , França , Prevalência
16.
Trends Microbiol ; 31(12): 1276-1286, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37652786

RESUMO

In silico and experimental approaches have allowed an ever-growing understanding of the interactions within the microbiota. For instance, recently acquired data have increased knowledge of the mechanisms that support, in the gut and vaginal microbiota, the resistance to colonization by Candida albicans, an opportunistic fungal pathogen whose overgrowth can initiate severe infections in immunocompromised patients. Here, we review how bacteria from the microbiota interact with C. albicans. We show how recent OMICs-based pipelines, using metagenomics and/or metabolomics, have identified bacterial species and metabolites modulating C. albicans growth. We finally discuss how the combined use of cutting-edge OMICs-based and experimental approaches could provide new means to control C. albicans overgrowth within the microbiota and prevent its consequences.


Assuntos
Microbioma Gastrointestinal , Microbiota , Feminino , Humanos , Candida albicans/genética , Antifúngicos/farmacologia , Metabolômica , Bactérias
17.
Front Cell Infect Microbiol ; 13: 1183340, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37502605

RESUMO

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 Aspergillus fumigatus with D-FF-OCT to follow the fungal growth stages. Methods: The A. fumigatus 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 A. fumigatus, 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.


Assuntos
Aspergillus fumigatus , Tomografia de Coerência Óptica , Ágar/farmacologia , Antifúngicos/farmacologia , Glucose
18.
Chest ; 164(5): 1097-1107, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37419276

RESUMO

BACKGROUND: Pulmonary mucormycosis (PM) is a life-threatening invasive mold infection. Diagnosis of mucormycosis is challenging and often delayed, resulting in higher mortality. RESEARCH QUESTION: Are the disease presentation of PM and contribution of diagnosis tools influenced by the patient's underlying condition? STUDY DESIGN AND METHODS: All PM cases from six French teaching hospitals between 2008 and 2019 were retrospectively reviewed. Cases were defined according to updated European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria with the addition of diabetes and trauma as host factors and positive serum or tissue PCR as mycologic evidence. Thoracic CT scans were reviewed centrally. RESULTS: A total of 114 cases of PM were recorded, including 40% with disseminated forms. Main underlying conditions were hematologic malignancy (49%), allogeneic hematopoietic stem cell transplantation (21%), and solid organ transplantation (17%). When disseminated, main dissemination sites were the liver (48%), spleen (48%), brain (44%), and kidneys (37%). Radiologic presentation included consolidation (58%), pleural effusion (52%), reversed halo sign (26%), halo sign (24%), vascular abnormalities (26%), and cavity (23%). Serum quantitative polymerase chain reaction (qPCR) was positive in 42 (79%) of 53 patients and BAL in 46 (50%) of 96 patients. Results of transthoracic lung biopsy were diagnostic in 8 (73%) of 11 patients with noncontributive BAL. Overall 90-day mortality was 59%. Patients with neutropenia more frequently displayed an angioinvasive presentation, including reversed halo sign and disseminated disease (P < .05). Serum qPCR was more contributive in patients with neutropenia (91% vs 62%; P = .02), and BAL was more contributive in patients without neutropenia (69% vs 41%; P = .02). Serum qPCR was more frequently positive in patients with a > 3 cm main lesion (91% vs 62%; P = .02). Overall, positive qPCR was associated with an early diagnosis (P = .03) and treatment onset (P = .01). INTERPRETATION: Neutropenia and radiologic findings influence disease presentation and contribution of diagnostic tools during PM. Serum qPCR is more contributive in patients with neutropenia and BAL examination in patients without neutropenia. Results of lung biopsies are highly contributive in cases of noncontributive BAL.


Assuntos
Pneumopatias Fúngicas , Mucormicose , Neutropenia , Humanos , Mucormicose/diagnóstico , Mucormicose/terapia , Estudos Retrospectivos , Pneumopatias Fúngicas/diagnóstico
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