RESUMO
The hyphal surface of cells of filamentous fungi is covered with cell wall, which is mainly composed of polysaccharides. Since the cell wall is the first structure to come in contact with the infection host, the environment, and the fungus itself, the elucidation of the cell wall structure and biogenesis is essential for understanding fungal ecology. Among filamentous fungi, the genus Aspergillus is an important group in the industrial, food, and medical fields. It is known that Aspergillus species form hyphal pellets in shake liquid culture. The authors previously found the role of α-1,3-glucan in hyphal aggregation in Aspergillus species. In addition, extracellular polysaccharide galactosaminogalactan contributed to hyphal aggregation as well, and dual disruption of biosynthesis genes of α-1,3-glucan and galactosaminogalactan resulted in complete hyphal dispersion in shake liquid culture. The characteristic of mycelia to form pellets under liquid culture conditions was the main reason why the growth measurement methods used for unicellular organisms could not be applied. We reported that hyphal growth of the dual disruption mutant could be measured by optical density. A real-time plate reader could be used to determine the growth curve of the mycelial growth of the dual disruption mutant. This measurement approach not only provides basic microbiological insights in filamentous fungi, but also has the potential to be applied to high-throughput screening of anti-Aspergillus drugs.
Assuntos
Aspergillus , Parede Celular , Hifas , Hifas/crescimento & desenvolvimento , Aspergillus/genética , Glucanos/metabolismo , Microbiologia Industrial/métodosRESUMO
Hyphal pellet formation by Aspergillus species in liquid cultures is one of the main obstacles to high-throughput anti-Aspergillus reagent screening. We previously constructed a hyphal dispersion mutant of Aspergillus fumigatus by disrupting the genes encoding the primary cell wall α-1,3-glucan synthase Ags1 and putative galactosaminogalactan synthase Gtb3 (Δags1Δgtb3). Mycelial growth of the mutant in liquid cultures monitored by optical density was reproducible, and the dose-response of hyphal growth to antifungal agents has been quantified by optical density. However, Δags1Δgtb3 still forms hyphal pellets in some rich growth media. Here, we constructed a disruptant lacking all three α-1,3-glucan synthases and galactosaminogalactan synthase (Δags1Δags2Δags3Δgtb3), and confirmed that its hyphae were dispersed in all the media tested. We established an automatic method to monitor hyphal growth of the mutant in a 24-well plate shaken with a real-time plate reader. Dose-dependent growth suppression and unique growth responses to antifungal agents (voriconazole, amphotericin B, and micafungin) were clearly observed. A 96-well plate was also found to be useful for the evaluation of mycelial growth by optical density. Our method is potentially applicable to high-throughput screening for anti-Aspergillus agents.
Assuntos
Antifúngicos , Aspergillus fumigatus , Animais , Aspergillus fumigatus/genética , Antifúngicos/farmacologia , Hifas/genética , Micélio , Anfotericina BRESUMO
Nelfinavir, an orally administered inhibitor of human immunodeficiency virus protease, inhibits the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. We conducted a randomized controlled trial to evaluate the clinical efficacy and safety of nelfinavir in patients with SARS-CoV-2 infection. We included unvaccinated asymptomatic or mildly symptomatic adult patients who tested positive for SARS-CoV-2 infection within 3 days before enrollment. The patients were randomly assigned (1:1) to receive oral nelfinavir (750 mg; thrice daily for 14 days) combined with standard-of-care or standard-of-care alone. The primary endpoint was the time to viral clearance, confirmed using quantitative reverse-transcription PCR by assessors blinded to the assigned treatment. A total of 123 patients (63 in the nelfinavir group and 60 in the control group) were included. The median time to viral clearance was 8.0 (95% confidence interval [CI], 7.0 to 12.0) days in the nelfinavir group and 8.0 (95% CI, 7.0 to 10.0) days in the control group, with no significant difference between the treatment groups (hazard ratio, 0.815; 95% CI, 0.563 to 1.182; P = 0.1870). Adverse events were reported in 47 (74.6%) and 20 (33.3%) patients in the nelfinavir and control groups, respectively. The most common adverse event in the nelfinavir group was diarrhea (49.2%). Nelfinavir did not reduce the time to viral clearance in this setting. Our findings indicate that nelfinavir should not be recommended in asymptomatic or mildly symptomatic patients infected with SARS-CoV-2. The study is registered with the Japan Registry of Clinical Trials (jRCT2071200023). IMPORTANCE The anti-HIV drug nelfinavir suppresses the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. However, its efficacy in patients with COVID-19 has not been studied. We conducted a multicenter, randomized controlled trial to evaluate the efficacy and safety of orally administered nelfinavir in patients with asymptomatic or mildly symptomatic COVID-19. Compared to standard-of-care alone, nelfinavir (750 mg, thrice daily) did not reduce the time to viral clearance, viral load, or the time to resolution of symptoms. More patients had adverse events in the nelfinavir group than in the control group (74.6% [47/63 patients] versus 33.3% [20/60 patients]). Our clinical study provides evidence that nelfinavir, despite its antiviral effects on SARS-CoV-2 in vitro, should not be recommended for the treatment of patients with COVID-19 having no or mild symptoms.
Assuntos
Fármacos Anti-HIV , COVID-19 , Adulto , Humanos , SARS-CoV-2 , Nelfinavir/efeitos adversos , Fatores de Tempo , Resultado do TratamentoRESUMO
Invasive fungal infection (IFI) has a high mortality rate in patients who undergo hematopoietic stem cell transplantation, and it is often confirmed by postmortem dissection. When IFI is initially confirmed after an autopsy, the tissue culture and frozen section are challenging to secure, and in many cases, formalin-fixed, paraffin-embedded (FFPE) samples represent the only modality for identifying fungi. Histopathological diagnosis is a useful method in combination with molecular biological methods that can achieve more precise identification with reproducibility. Meanwhile, polymerase chain reaction (PCR) using fungal-specific primers helps identify fungi from FFPE tissues. Autopsy FFPE specimens have a disadvantage regarding the quality of DNA extracted compared with that of specimens obtained via biopsy or surgery. In the case of mucormycosis diagnosed postmortem histologically, we examined currently available molecular biological methods such as PCR, immunohistochemistry (IHC), and in situ hybridization (ISH) to identify fungi. It is reasonable that PCR with some modification is valuable for identifying fungi in autopsy FFPE specimens. However, PCR does not always correctly identify fungi in autopsy FFPE tissues, and other approaches such as ISH or IHC are worth considering for clarifying the broad classification (such as the genus- or species-level classification).
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Background: Candida glabrata is an emerging fungal pathogen in immune-compromised hosts. Previously undetected C. glabrata isolates were successfully recovered from clinical specimens by adding sterols to the growth medium. The clinical isolates are unable to synthesize ergosterol but can take up exogenous sterols under aerobic conditions. Objectives: This study characterizes the sterol-auxotrophic C. glabrata strains, examines the mutation(s) in sterol synthesis genes, characterizes the drug susceptibility and evaluates the virulence in a mouse infection model. Methods: Drug susceptibility of the C. glabrata strains was evaluated in a sterol-supplemented medium. The coding sequences of the sterol synthesis genes were analysed in six sterol-auxotrophic strains of C. glabrata. The fungal burden of mice infected with C. glabrata strain was determined. Results: The sterol-auxotrophic strains showed high-level resistance to both azoles and amphotericin B when sterols were supplied in the test medium. Additionally, the strains harbour missense mutations in either ERG1 or ERG7. Significant differences in fungal burden were not observed between the sterol-auxotrophic strain and the sterol-competent strain with the mice infection models. Conclusions: The sterol-auxotrophic C. glabrata strain investigated in this study seemed to maintain intact virulence, probably due to the supply of exogenous sterols from host organ(s). This suggests that exogenous sterol uptake develops antifungal resistance during infection.
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Aspergillus lentulus was first reported in 2005 as a cryptic species of Aspergillus fumigatus, and since then, its resistance to azole drugs and the high mortality rate of infected individuals have emerged as problems. Although it has been reported that P450 14-α sterol demethylase (Cyp51) is involved in azole resistance in A. lentulus, the specific resistance mechanism has not been elucidated. In this study, we successfully introduced the entire A. fumigatus cyp51A gene into the cyp51A locus in A. lentulus using the CRISPR/Cas9 genome-editing system. The A. lentulus strains harboring A. fumigatus cyp51A showed reduced minimum inhibitory concentrations for itraconazole and voriconazole compared with those of the parent strain. This finding suggests that Cyp51A is involved in azole resistance in A. lentulus and may contribute to the elucidation of the mechanism of resistance to azole drugs via Cyp51A and to the development of new antifungal drugs. In addition, our successful application of the CRISPR/Cas9 system to A. lentulus opens the door to examination of other gene functions in this fungus.
Assuntos
Azóis , Farmacorresistência Fúngica , Antifúngicos/farmacologia , Aspergillus , Aspergillus fumigatus/genética , Azóis/farmacologia , Sistemas CRISPR-Cas , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Edição de Genes , Humanos , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: Protothecosis is a rare infection in humans and animals caused by the achlorophyllic algae Prototheca species. More than half of the protothecosis cases are cutaneous infections, and most cases are observed in immunocompromised individuals. CASE PRESENTATION: We report a case of Prototheca wickerhamii infection in the mucosa of the pharynx in a 53-year-old immunocompetent woman with an incidentally found mass lesion at the left tongue base. Histopathological findings of the mass lesion suggested cryptococcosis, but P. wickerhamii was identified from the oropharynx scrape culture based on DNA sequencing. After surgical resection, fosfluconazole treatment was initiated, and subsequently, treatment was switched to topical amphotericin B. The residual mass lesion did not deteriorate during the 4-month antifungal treatment and 1-year observational period. CONCLUSIONS: Prototheca species can be easily misdiagnosed as yeasts because of their morphological and pathological similarities. Prototheca, in addition to Cryptococcus should be considered if slow-growing, large Gram-positive organisms are encountered. Lactophenol cotton blue staining of the colony helps distinguish these organisms. Further study is needed to determine the appropriate treatment according to the infection focus.
Assuntos
Prototheca/isolamento & purificação , Dermatopatias Infecciosas/diagnóstico , Animais , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Mucosa , Neoplasias Faríngeas/diagnóstico , Faringe , Prototheca/genética , Análise de Sequência de DNA , Pele/patologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Filamentous fungi form multicellular hyphae, which generally form pellets in liquid shake cultures, during the vegetative growth stage. Because of these characteristics, growth-monitoring methods commonly used in bacteria and yeast have not been applied to filamentous fungi. We have recently revealed that the cell wall polysaccharide α-1,3-glucan and extracellular polysaccharide galactosaminogalactan (GAG) contribute to hyphal aggregation in Aspergillus oryzae. Here, we tested whether Aspergillus fumigatus shows dispersed growth in liquid media that can be quantitatively monitored, similar to that of yeasts. We constructed a double disruptant mutant of both the primary α-1,3-glucan synthase gene ags1 and the putative GAG synthase gene gtb3 in A. fumigatus AfS35 and found that the hyphae of this mutant were fully dispersed. Although the mutant lost α-1,3-glucan and GAG, its growth and susceptibility to antifungal agents were not different from those of the parental strain. Mycelial weight of the mutant in shake-flask cultures was proportional to optical density for at least 18 h. We were also able to quantify the dose response of hyphal growth to antifungal agents by measuring optical density. Overall, we established a convenient strategy to monitor A. fumigatus hyphal growth. Our method can be directly used for screening for novel antifungals against Aspergillus species. IMPORTANCE Filamentous fungi generally form hyphal pellets in liquid culture. This property prevents filamentous fungi so that we may apply the methods used for unicellular organisms such as yeast and bacteria. In the present study, by using the fungal pathogen Aspergillus fumigatus strain with modified hyphal surface polysaccharides, we succeeded in monitoring the hyphal growth quantitatively by optical density. The principle of this easy measurement by optical density could lead to a novel standard of hyphal quantification such as those that have been used for yeasts and bacteria. Dose response of hyphal growth by antifungal agents could also be monitored. This method could be useful for screening for novel antifungal reagents against Aspergillus species.
Assuntos
Aspergillus fumigatus/química , Aspergillus fumigatus/crescimento & desenvolvimento , Meios de Cultura/metabolismo , Espectrofotometria/métodos , Antifúngicos/farmacologia , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/genética , Parede Celular/genética , Parede Celular/metabolismo , Meios de Cultura/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Glucanos/metabolismo , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Hifas/química , Hifas/efeitos dos fármacos , Hifas/genética , Hifas/crescimento & desenvolvimento , Micélio/química , Micélio/efeitos dos fármacos , Micélio/genética , Micélio/crescimento & desenvolvimentoRESUMO
Limited data are available on breakthrough fungemia, defined as fungemia that develops on administration of antifungal agents, in patients with hematological disorders. We reviewed the medical and microbiological records of adult patients with hematological diseases who had breakthrough fungemia between January 2008 and July 2019 at Toranomon Hospital and Toranomon Hospital Kajigaya in Japan. A total of 121 cases of breakthrough fungemia were identified. Of the 121 involved patients, 83, 11, 5, and 22 were receiving micafungin, voriconazole, itraconazole, and liposomal amphotericin B, respectively, when the breakthrough occurred. Of the 121 causative breakthrough fungal strains, 96 were Candida species, and the rest were 13 cases of Trichosporon species, 7 of Fusarium species, 2 of Rhodotorula mucilaginosa, and 1 each of Cryptococcus neoformans, Exophiala dermatitidis, and Magnusiomyces capitatus. The crude 14-day mortality rate of breakthrough fungemia was 36%. Significant independent factors associated with the crude 14-day mortality rate were age of ≥60 years (P = 0.011), chronic renal failure (P = 0.0087), septic shock (P < 0.0001), steroid administration (P = 0.0085), and liposomal amphotericin B breakthrough fungemia (P = 0.0011). An absolute neutrophil count of >500/µL was significantly more common in candidemia in the multivariate analysis (P = 0.0065), neutropenia and nonallogeneic hematopoietic stem cell transplants were significantly more common in Trichosporon fungemia (P = 0.036 and P = 0.033, respectively), and voriconazole breakthrough fungemia and neutropenia were significantly more common in Fusarium fungemia (P = 0.016 and P = 0.016, respectively). The epidemiological and clinical characteristics of breakthrough fungemia of patients with hematological disorders were demonstrated. Some useful factors to predict candidemia, Trichosporon fungemia, and Fusarium fungemia were identified.
Assuntos
Candidemia , Cryptococcus neoformans , Fungemia , Fusarium , Doenças Hematológicas , Trichosporon , Adulto , Antifúngicos/uso terapêutico , Candida , Candidemia/tratamento farmacológico , Fungemia/tratamento farmacológico , Fungemia/microbiologia , Doenças Hematológicas/complicações , Doenças Hematológicas/tratamento farmacológico , Humanos , Pessoa de Meia-IdadeRESUMO
There are few reports on the clinical course of proven invasive aspergillosis (IA) due to rare/cryptic species in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. We retrospectively reviewed the electronic medical records of patients who underwent allo-HSCT between January 2012 and December 2018. Of 934 allo-HSCT recipients, 10 were diagnosed with proven IA and 61 were diagnosed with probable IA. DNA sequencing was performed in cases of proven IA, and Aspergillus could be identified to the species level in 8 of the 10 cases. Three were due to A. fumigatus, and 5 were due to rare/cryptic Aspergillus species, namely, A. turcosus, A. felis, A. viridinutans, A. nidulans, and A. calidoustus. In these 8 patients, no patients with IA due to A. fumigatus died, whereas 3 of the 5 with IA due to rare/cryptic species died within 12 weeks. The 2 surviving cases of IA due to rare/cryptic species were treated with surgical resection and antifungal treatment. Susceptibility testing for cryptic species in 4 cases showed an amphotericin B MIC > 1 mg/L in 3 cases, itraconazole MIC > 1 mg/L in 2 cases, and voriconazole MIC > 1 mg/L in 2 cases. In conclusion, more than half of the causative pathogens of proven IA were rare/cryptic species, so it is important to accurately identify the Aspergillus species. In addition, surgical treatment might be an important option in cases of proven IA, given the possibility that the causative organisms are azole-resistant A. fumigatus or rare/cryptic species.
Assuntos
Aspergilose , Transplante de Células-Tronco Hematopoéticas , Infecções Fúngicas Invasivas , Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergillus/genética , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Infecções Fúngicas Invasivas/tratamento farmacológico , Estudos RetrospectivosRESUMO
Triazole-resistant Aspergillus fumigatus is a global health concern. In general, each triazole resistance pattern caused by the specified amino acid substitution of Cyp51A has a typical pattern depending on the mutation site. We evaluated the contribution of both Cyp51A and Hmg1 mutations to atypical triazole resistance in A. fumigatus. We used clinical triazole-resistant A. fumigatus strains collected in Japan and investigated the sequences of cyp51A and hmg1 genes. To delineate the association between the hmg1 mutation and atypical triazole resistance, the mutant hmg1 alleles in clinical multi-azole resistant strains were replaced with the wild-type hmg1 allele by CRISPR/Cas9 system. In our study, the combination of Cyp51A mutation and Hmg1 mutation was shown to additively contribute to triazole resistance. We also demonstrated that the triazole resistance conferred by the Hmg1 mutation showed a different pattern depending on the mutation site, similar to the Cyp51A mutation. Our results indicate that focusing on the phenotypes of multiple genes is essential to clarify the overall picture of the triazole resistance mechanism of A. fumigatus. LAY SUMMARY: The number of triazole-resistant Aspergillus fumigatus is increasing. We confirmed thatmutation in a hydroxymethylglutaryl-CoA reductase (Hmg1) in the fungus contributesto the resistance separately from Cyp51A mutation, and that susceptibility patterns aredifferent based on mutation site.
Assuntos
Aspergillus fumigatus , Triazóis , Animais , Antifúngicos/farmacologia , Aspergillus fumigatus/genética , Sistema Enzimático do Citocromo P-450/genética , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Testes de Sensibilidade Microbiana/veterinária , Mutação , Triazóis/farmacologiaRESUMO
A 42-year-old man diagnosed with acute myeloid leukemia complained of progressive swelling of the right side of his face with pain 11 days after the third cycle of consolidation therapy with high-dose arabinosylcytosine-cytarabine. Head and neck magnetic resonance imaging showed a mass lesion in his right maxillary sinus with parapharyngeal involvement, which included the right masseter muscle, intraorbital involvement, and an abscess in his brain. Chest computed tomography revealed peribronchial small nodules in his right upper lobe and a necrotic tumor in his right lower lobe. Molds identified as Cunninghamella bertholletiae were isolated from the necrotic ulcer. According to these results, chemotherapy for leukemia was discontinued. High-dose liposomal amphotericin (10 mg/kg/day) was initiated. Because renal dysfunction occurred, the dosage was decreased to 6 mg/kg and combined with 150 mg/day micafungin. Debridement of necrotic tissue in the right maxillary sinus and establishment of the fenestration between the sinus and oral cavity were performed. Subsequently, brain and lung lesions were surgically removed. Rhinocerebral mucormycosis was successfully treated without relapse over 3 years by a 112-day course of intravenous anti-fungal therapy and 223-day course of terbinafine and partial surgical removal, respectively, to maintain masticatory and ocular functions. To our knowledge, there has been no other report of a long-term survival case of rhinocerebral mucormycosis due to C. bertholletiae.
Assuntos
Infecções Fúngicas do Sistema Nervoso Central , Cunninghamella , Leucemia Mieloide Aguda , Pneumopatias Fúngicas , Mucormicose , Adulto , Antifúngicos/uso terapêutico , Antineoplásicos/uso terapêutico , Humanos , Leucemia Mieloide Aguda/complicações , Leucemia Mieloide Aguda/tratamento farmacológico , Pulmão/patologia , MasculinoRESUMO
ß-1,3-d-Glucan is a ubiquitous glucose polymer produced by plants, bacteria, and most fungi. It has been used as a diagnostic tool in patients with invasive mycoses via a highly-sensitive reagent consisting of the blood coagulation system of horseshoe crab. However, no method is currently available for measuring ß-1,6-glucan, another primary ß-glucan structure of fungal polysaccharides. Herein, we describe the development of an economical and highly-sensitive and specific assay for ß-1,6-glucan using a modified recombinant endo-ß-1,6-glucanase having diminished glucan hydrolase activity. The purified ß-1,6-glucanase derivative bound to the ß-1,6-glucan pustulan with a KD of 16.4 nm We validated the specificity of this ß-1,6-glucan probe by demonstrating its ability to detect cell wall ß-1,6-glucan from both yeast and hyphal forms of the opportunistic fungal pathogen Candida albicans, without any detectable binding to glucan lacking the long ß-1,6-glucan branch. We developed a sandwich ELISA-like assay with a low limit of quantification for pustulan (1.5 pg/ml), and we successfully employed this assay in the quantification of extracellular ß-1,6-glucan released by >250 patient-derived strains of different Candida species (including Candida auris) in culture supernatant in vitro We also used this assay to measure ß-1,6-glucan in vivo in the serum and in several organs in a mouse model of systemic candidiasis. Our work describes a reliable method for ß-1,6-glucan detection, which may prove useful for the diagnosis of invasive fungal infections.
Assuntos
Técnicas Biossensoriais/métodos , Polissacarídeos Fúngicos/química , Glicosídeo Hidrolases/metabolismo , Polissacarídeos/análise , beta-Glucanas/análise , Animais , Candida/metabolismo , Ensaios Enzimáticos/métodos , Feminino , Polissacarídeos Fúngicos/metabolismo , Glicosídeo Hidrolases/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Polissacarídeos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , beta-Glucanas/metabolismoRESUMO
Candida auris is an invasive and multidrug-resistant ascomycetous yeast that is under global surveillance. All clinical cases of C. auris infection diagnosed from 1997 to 2019 in Japan were non-invasive and sporadic otitis media cases. In the present study, we performed whole-genome sequencing of seven C. auris strains isolated from patients with otitis media in Japan, all of which belonged to clade II. Comparative genome analysis using the high-quality draft genome sequences JCM 15448T revealed that single nucleotide variations (SNVs), clade-specific accessory genes, and copy number variations (CNVs) were identified in each C. auris clade. A total of 61 genes involved in cell wall and stress response-related functions was absent in clade II, and the pattern of conserved CNVs in each clade was more stable in clade II than in other clades. Our data suggest that the genomic structural diversity is stable in C. auris isolated from each biogeographic location, and Japanese strains isolated from patients with otitis media might belong to an ancestral type of C. auris. One Japanese strain, TWCC 58362, with reduced susceptibility to fluconazole, exhibited no mutation in ergosterol biosynthesis-related genes (ERG). However, TWCC 58362-specific variations, including SNVs, indels, and CNVs were detected, suggesting that gene duplication events in C. auris might contribute to antifungal drug resistance. Taken together, we demonstrated that genomic structural variations in C. auris could correlate to geographical dissemination, epidemiology, lesions in the host, and antifungal resistance.
Assuntos
Candida/genética , Genoma Fúngico , Filogenia , Polimorfismo Genético , Candida/classificação , Candida/metabolismo , Sequência Conservada , Evolução Molecular , Estresse Fisiológico/genéticaRESUMO
RATIONALE: Histoplasmosis occurs most commonly in Northern and Central America and Southeast Asia. Increased international travel in Japan has led to a few annual reports of imported histoplasmosis. Healed sites of histoplasmosis lung infection may remain as nodules and are often accompanied by calcification. Previous studies in endemic areas supported the hypothesis that new infection/reinfection, rather than reactivation, is the main etiology of symptomatic histoplasmosis. No previous reports have presented clinical evidence of reactivation. PATIENT CONCERNS: An 83-year-old Japanese man was hospitalized with general fatigue and high fever. He had been treated with prednisolone at 13âmg/d for 7 years because of an eczematous skin disease. He had a history of travel to Los Angeles, Egypt, and Malaysia 10 to 15 years prior to admission. Five years earlier, computed tomography (CT) identified a solitary calcified nodule in the left lingual lung segment. The nodule size remained unchanged throughout a 5-year observation period. Upon admission, his respiratory condition remained stable while breathing room air. CT revealed small, randomly distributed nodular shadows in the bilateral lungs, in addition to the solitary nodule. DIAGNOSIS: Disseminated histoplasmosis, based on fungal staining and cultures of autopsy specimens. INTERVENTIONS: The patient's fever continued despite several days of treatment with meropenem, minocycline, and micafungin. Although he refused bone marrow aspiration, isoniazid, rifampicin, ethambutol, and prednisolone were administered for a tentative diagnosis of miliary tuberculosis. OUTCOMES: His fever persisted, and a laboratory examination indicated severe thrombocytopenia with disseminated intravascular coagulation. He died on day 43 postadmission. During autopsy, the fungal burden was noted to be higher in the calcified nodule than in the disseminated nodules of the lung, suggesting a pathogenesis involving endogenous reactivation of the nodule and subsequent hematogenous and lymphatic spread. LESSONS: Physicians should consider histoplasmosis in patients with calcified nodules because the infection may reactivate during long-term corticosteroid therapy.
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Histoplasmose/patologia , Pneumopatias Fúngicas/patologia , Idoso de 80 Anos ou mais , Calcinose , Eczema/complicações , Eczema/tratamento farmacológico , Glucocorticoides/uso terapêutico , Histoplasmose/complicações , Humanos , Hospedeiro Imunocomprometido , Japão , Pneumopatias Fúngicas/complicações , Masculino , Tomografia Computadorizada por Raios XRESUMO
Aspergillus fumigatus is a critical human fungal pathogen that infects the host via inhalation of airborne conidia. These conidia then germinate to form filamentous hyphae, which secrete various elements to survive in the host lung.Elements such as proteins secreted by A. fumigatus can act as virulence factors in host tissues. Among secreted proteins, we were interested in the thaumatin-like proteins of A. fumigatus. In our analysis of the function of thaumatin-like proteins, we found that, like CalA and CalB, CalC has a secreted form. Originally, CalC was predicted to be a GPI-anchored protein, as documented in the Aspergillus Genome Database. Here, we report on a novel secreted form of CalC. Furthermore, we established two novel hybridomas, C103 and C306, which recognized CalC. Monoclonal antibodies produced by these hybridomas responded to recombinant CalC produced by the mammalian cell line HEK293T and to the supernatant of cultured A. fumigatus.Taken together, our data suggest that calC can be spliced to give rise to a novel secretory form of CalC, which is present in the supernatant of cultured A. fumigatus. The hybridomas that we established will be helpful in understanding the biological role of A. fumigatus CalC.
Assuntos
Anticorpos Monoclonais , Aspergillus fumigatus/genética , Aspergillus fumigatus/imunologia , Proteínas Fúngicas , Aspergillus fumigatus/patogenicidade , Aspergillus fumigatus/fisiologia , Proteínas Fúngicas/metabolismo , Células HEK293/metabolismo , Humanos , Hifas/metabolismo , Pulmão/microbiologia , VirulênciaRESUMO
A pan-azole-resistant Aspergillus fumigatus strain with the cyp51A mutations Gly138Ser and Asn248Lys was isolated from a patient receiving long-term voriconazole treatment. PCR fragments containing cyp51A with the mutations were introduced along with the Cas9 protein and single guide RNA into the azole-resistant/susceptible strains. Recombinant strains showed increased susceptibility via the replacement of Ser138 by glycine. Genetic recombination, which has been hampered thus far in clinical isolates, can now be achieved using CRISPR/Cas9 genome editing.
Assuntos
Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/genética , Sistema Enzimático do Citocromo P-450/genética , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Edição de Genes/métodos , Voriconazol/uso terapêutico , Idoso , Aspergillus fumigatus/isolamento & purificação , Sistemas CRISPR-Cas/genética , Humanos , MasculinoRESUMO
A 71-year-old Japanese man with travel history to the Vancouver Island, Canada was diagnosed the pulmonary and central nervous system infections caused by Cryptococcus gattii genotype VGIIa. This is the first imported case of Cryptococcus gattii genotype VGIIa infection from endemic area of North America to Japan. He was recovery with no residual neurological dysfunction by early resection of brain mass and antifungal therapy. Early surgical resection of cerebellar cryptococcoma may shorten the length of induction therapy with antifungal drugs.
Assuntos
Infecções Fúngicas do Sistema Nervoso Central/microbiologia , Criptococose/microbiologia , Cryptococcus gattii/genética , Pneumopatias Fúngicas/microbiologia , Idoso , Antifúngicos/uso terapêutico , Antígenos de Fungos/sangue , Antígenos de Fungos/líquido cefalorraquidiano , Canadá , Infecções Fúngicas do Sistema Nervoso Central/tratamento farmacológico , Infecções Fúngicas do Sistema Nervoso Central/cirurgia , Angiografia por Tomografia Computadorizada , Criptococose/tratamento farmacológico , Cryptococcus gattii/classificação , Cryptococcus gattii/isolamento & purificação , Genótipo , Humanos , Japão , Pneumopatias Fúngicas/tratamento farmacológico , Imageamento por Ressonância Magnética , Masculino , Tipagem de Sequências Multilocus , Radiografia , Análise de Sequência de DNARESUMO
The efficacy of recombinant interferon γ (rIFN-γ) for cryptococcal meningoencephalitis has been poorly understood. Compared to Cryptococcus gattii, rIFN-γ significantly improved the survival in experimental meningoencephalitis due to Cryptococcus neoformans. The number of phagocytic macrophages and the levels of inflammatory cytokines production for ex vivo co-incubation with C. neoformans were increased after rIFN-γ stimulation but not C. gattii. Intraspecies differences of phagocytosis by the rIFN-γ-activated macrophages might be associated to the severity of cryptococcal infection.
Assuntos
Interferon gama/uso terapêutico , Macrófagos/efeitos dos fármacos , Meningoencefalite/tratamento farmacológico , Animais , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Linhagem Celular , Contagem de Colônia Microbiana , Cryptococcus gattii/efeitos dos fármacos , Cryptococcus gattii/patogenicidade , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/patogenicidade , Modelos Animais de Doenças , Feminino , Interferon gama/farmacologia , Macrófagos/citologia , Macrófagos/metabolismo , Meningoencefalite/microbiologia , Meningoencefalite/mortalidade , Meningoencefalite/patologia , Camundongos , Camundongos Endogâmicos C57BL , Fagocitose/efeitos dos fármacos , Especificidade da Espécie , Taxa de Sobrevida , VirulênciaRESUMO
Leukocyte cell-derived chemotaxin 2 (LECT2) is a secreted pleiotropic protein that is mainly produced by the liver. We have previously shown that LECT2 plays an important role in the pathogenesis of inflammatory liver diseases. Lipopolysaccharide/d-galactosamine (LPS/d-GalN)-induced acute liver injury is a known animal model of fulminant hepatic failure. Here we found that this hepatic injury was alleviated in LECT2-deficient mice. The levels of TNF-α and IFN-γ, which mediate this hepatitis, had significantly decreased in these mice, with the decrease in IFN-γ production notably greater than that in TNF-α. We therefore analyzed IFN-γ-producing cells in liver mononuclear cells. Flow cytometric analysis showed significantly reduced IFN-γ production in hepatic NK and NKT cells in LECT2-deficient mice compared with in wild-type mice. We also demonstrated a decrease in IFN-γ production in LECT2-deficient mice after systemic administration of recombinant IL-12, which is known to induce IFN-γ in NK and NKT cells. These results indicate that a decrease of IFN-γ production in NK and NKT cells was involved in the alleviation of LPS/d-GalN-induced liver injury in LECT2-deficient mice.