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1.
Cushing's disease with pulmonary Cryptococcus neoformans infection in a single center in Beijing, China: A retrospective study and literature review.
Lu, L, Zhao, YY, Yang, HB, Tian, XL, Xu, ZJ, Lu, ZL
Journal of the Formosan Medical Association = Taiwan yi zhi. 2019;(1 Pt 2):285-290
Abstract
BACKGROUND Patients with Cushing's disease (CD) with hypercortisolism have an increased risk of opportunistic infection. However, most CD patients exposed to infections are diagnostic latency, leading to a poor prognosis. METHODS Six patients in our hospital and an additional six patients in the literature were included in this study. Clinical information of CD patients with pulmonary Cryptococcus neoformans are reviewed. RESULTS The average baseline total cortisol and ACTH in serum at 8 am of all the patients was 44.85 μg/dL (normal range 4.0-22.3 μg/dL) and 200.3 pg/mL (normal range 0-46 pg/mL), respectively. Lymphopenia was found in 2 out of 6 patients in our hospital. The pulmonary radiologic findings included nodules (4/12), masses with or without a cavity (5/12), infiltration (5/12), and consolidation (4/12). The diagnosis of C.neoformans was established by lung pathology results (7/12), microorganism culture (3/12), and serum cryptococcal polysaccharide antigen (4/12). Lung lobectomy was performed in two patients who had a nodule in one lung lobe. Antifungal drugs were administered, including amphotericin-B (7/12), fluconazole (4/12), flucytosine (2/12) and liposomal amphotericin (1/12). Additional therapies for CD included trans-sphenoidal pituitary adenoma surgery (9/12), adrenalectomy (1/12) and ketoconazole (2/12). Seven patients survived, and five patients died. CONCLUSION Pulmonary C.neoformans is an uncommon but fatal opportunistic infection in CD patients. Pulmonary nodules or masses should be aggressively investigated to exclude the C.neoformans among CD patients. The infiltration lesions in chest CT scan and lymphopenia are associated with poor prognosis.
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2.
Emerging Mechanisms of Drug Resistance in Candida albicans.
Prasad, R, Nair, R, Banerjee, A
Progress in molecular and subcellular biology. 2019;:135-153
Abstract
Drug resistance mechanisms in the commensal human pathogen Candida albicans are continually evolving. Over time, Candida species have implemented diverse strategies to vanquish the effects of various classes of drugs, thereby emanating as a serious life threat. Apart from the repertoire of well-established strategies, which predominantly comprise permeability constraints, increased drug efflux or compromised drug import, alteration, overexpression of drug targets, and chromosome duplication, C. albicans has evolved novel regulatory mechanisms of drug resistance. For instance, recent evidences point to newer circuitry involving different mediators of the stress-responsive machinery of oxidative, osmotic, thermal, nitrosative, and nutrient limitation, which contribute to the emergence of drug resistance. Contemporary advances in genome-wide studies of transcription factors, for instance, the Zn2Cys6 transcription factors, TAC1 (transcriptional activator of CDR) in Candida albicans, or YRR1 in yeast have made it feasible to dissect their involvement for the elucidation of unexplored regulatory network of drug resistance. The coordination of implementers of the conventional and nonconventional drug resistance strategies provides robustness to this commensal human pathogen. In this review, we shed light not only on the established strategies of antifungal resistance but also discuss emerging cellular circuitry governing drug resistance of this human pathogen.
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3.
Calcium signaling pathway is involved in non-CYP51 azole resistance in Aspergillus fumigatus.
Li, Y, Zhang, Y, Lu, L
Medical mycology. 2019;(Supplement_2):S233-S238
Abstract
The opportunistic fungal pathogen Aspergillus fumigatus, which is one of the primary airborne ascomycete pathogens and allergens worldwide, causes invasive fungal infections, which have high morbidity and mortality rates among immunosuppressed patients. The abuse of azole antifungals results in serious drug resistance in clinical therapy. Thus, a thorough understanding of the azole drug resistance mechanism and screening of antifungal agents with a novel mode of action and new drug targets are required to fight against drug resistance. Current studies suggest that there are three major azole resistance mechanisms in fungal pathogens, including changes of the drug target Cyp51, activation of drug efflux pumps and induction of cellular stress responses. Fungi must adapt to a variety of external environmental stressors to survive. These obstacles include stress to the plasma membrane after azole antifungal treatments, high temperature, pH variation, and oxidative stress. As a filamentous fungus, A. fumigatus has evolved numerous signal-transduction systems to sense and respond to azole stresses to survive and proliferate in harsh environmental conditions. Among these signal-transduction systems, the Ca2+ signaling pathway is one of the most important response systems, which has been verified to be involved in stress adaptation. In this review, we have summarized how the components of the calcium-signaling pathway and their interaction network are involved in azole stress response in A. fumigatus.
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4.
[Update in the diagnostic and therapeutic approach of invasive aspergillosis in adult population].
Rabagliati, R
Revista chilena de infectologia : organo oficial de la Sociedad Chilena de Infectologia. 2018;(5):531-544
Abstract
The invasive fungal disease produced by Aspergillus spp., is the infection by filamentous fungi most frequently reported among immunocompromised individuals and responsible for a very high mortality in this group of patients. In recent years, important advances have been made both from the diagnostic and therapeutic point of view. At present, a series of risk factors associated with its development have been identified, allowing the categorization of patients in high, intermediate and low risk of invasive aspergillosis (IA); and diagnostic criteria have also been established that consider factors of the host, traditional mycological laboratory, biomarkers such as galactomannan and 1→3-β-d-glucan, together with the better understanding and interpretation of the tomographic images that have allowed to reach a consensus on the diagnostic categories. This added to the incorporation of new antifungals and therapeutic strategies in different scenarios, have allowed decreasing the associated mortality. In this review, are updated the epidemiological aspects, the risk factors, the diagnosis, prevention and prophylaxis as well as the therapeutic confrontation, including strategies for the use of empirical, precocious and directed antifungal therapy, as well as the most relevant aspects of the first-choice and alternative antifungals for the IA management.
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5.
The pathogenicity of Aspergillus fumigatus, drug resistance, and nanoparticle delivery.
Szalewski, DA, Hinrichs, VS, Zinniel, DK, Barletta, RG
Canadian journal of microbiology. 2018;(7):439-453
Abstract
The genus Aspergillus includes fungal species that cause major health issues of significant economic importance. These microorganisms are also the culprit for production of carcinogenic aflatoxins in grain storages, contaminating crops, and economically straining the production process. Aspergillus fumigatus is a very important pathogenic species, being responsible for high human morbidity and mortality on a global basis. The prevalence of these infections in immunosuppressed individuals is on the rise, and physicians struggle with the diagnosis of these deadly pathogens. Several virulence determinants facilitate fungal invasion and evasion of the host immune response. Metabolic functions are also important for virulence and drug resistance, since they allow fungi to obtain nutrients for their own survival and growth. Following a positive diagnostic identification, mortality rates remain high due, in part, to emerging resistance to frequently used antifungal drugs. In this review, we discuss the role of the main virulence, drug target, and drug resistance determinants. We conclude with the review of new technologies being developed to treat aspergillosis. In particular, microsphere and nanoparticle delivery systems are discussed in the context of improving drug bioavailability. Aspergillus will likely continue to cause problematic infections in immunocompromised patients, so it is imperative to improve treatment options.
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6.
Successful treatment of Aspergillus ventriculitis through voriconazole adaptive pharmacotherapy, immunomodulation, and therapeutic monitoring of cerebrospinal fluid (1→3)-β-D-glucan.
Chen, TK, Groncy, PK, Javahery, R, Chai, RY, Nagpala, P, Finkelman, M, Petraitiene, R, Walsh, TJ
Medical mycology. 2017;(1):109-117
Abstract
Aspergillus ventriculitis is an uncommon but often fatal form of invasive aspergillosis of the central nervous system (CNS). As little is known about the diagnosis, treatment, and outcome of this potentially lethal infection, we report the strategies used to successfully treat Aspergillus ventriculitis complicating a pineal and pituitary germinoma with emphasis on the critical role of adaptive pharmacotherapy of voriconazole and serial monitoring of (1→3)-β-D-glucan in cerebrospinal fluid. We describe several rationally based therapeutic modalities, including adaptive pharmacotherapy, combination therapy, sargramostim-based immunomodulation, and biomarker-based therapeutic monitoring of the CNS compartment. Through these strategies, our patient remains in remission from both his germinoma and Aspergillus ventriculitis making him one of the few survivors of Aspergillus ventriculitis.
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7.
Antifungal Prevention of Systemic Candidiasis in Immunocompetent ICU Adults: Systematic Review and Meta-Analysis of Clinical Trials.
Dupont, H, Mahjoub, Y, Chouaki, T, Lorne, E, Zogheib, E
Critical care medicine. 2017;(11):1937-1945
Abstract
OBJECTIVES The aim of this study was to identify the impact of antifungal prevention in critically ill immunocompetent adult patients on mortality and subsequent infection. DATA SOURCES A systematic review and meta-analysis of randomized controlled trials comparing any antifungal use versus placebo to prevent candidiasis in ICU patients were performed. STUDY SELECTION Searches were performed on PubMed, Embase, Scopus, main conference proceedings, and ClinicalTrials.gov, as well as reference lists. DATA EXTRACTION The primary outcomes were mortality and invasive candidiasis. The secondary outcome was the rate of Candida albicans and nonalbicans strains after treatment. A random effect model was used, and sensitivity analysis was performed for both outcomes. Results are expressed as risk ratios and their 95% CIs. DATA SYNTHESIS Nineteen trials (10 with fluconazole, four with ketoconazole, one with itraconazole, three with micafungin, and one with caspofungin) including 2,792 patients were identified. No individual trial showed a decreased mortality rate. Combined analysis showed that preventive antifungal did not decrease mortality (risk ratio, 0.88; 95% CI, 0.74-1.04; p = 0.14) but significantly decreased secondary fungal infections by 50% (risk ratio, 0.49; 95% CI, 0.35-0.68; p = 0.0001). No shift across nonalbicans strains was observed during treatment (risk ratio, 0.62; 95% CI, 0.19-1.97; p = 0.42). However, publication biases preclude any definite conclusions for prevention of infection. CONCLUSIONS Antifungal prevention of systemic candidiasis in immunocompetent critically ill adults did not reduce mortality and may have decreased secondary fungal infection rates. However, significant publication bias was present.
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8.
Tinea Capitis by Microsporum audouinii: Case Reports and Review of Published Global Literature 2000-2016.
Brito-Santos, F, Figueiredo-Carvalho, MHG, Coelho, RA, Sales, A, Almeida-Paes, R
Mycopathologia. 2017;(11-12):1053-1060
Abstract
Tinea capitis caused by Microsporum audouinii is reported herein from two Brazilian schoolchildren, which are brothers. Arthroconidia were evidenced on direct examination of scalp hair, and a fungus of the genus Microsporum was isolated from cultures of each patient. The isolated fungi were classified as M. audouinii by visualization of species-specific structures, including: pectinate hyphae, chlamydospores, and fusiform macroconidia, sterile growth with characteristic brown pigment in rice grains, and through DNA sequencing of the internal transcriber spacer region. Patients were refractory to ketoconazole, but the two cases had a satisfactory response to oral terbinafine. All M. audouinii infections described in this century were reviewed, and to our knowledge, this is the first literature description of this species from South America. Misidentification of M. audouinii with Microsporum canis can occur in this area, leading to erroneous data about the occurrence of this species.
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9.
Antifungal effects of phytocompounds on Candida species alone and in combination with fluconazole.
Lu, M, Li, T, Wan, J, Li, X, Yuan, L, Sun, S
International journal of antimicrobial agents. 2017;(2):125-136
Abstract
Invasive fungal infections caused by Candida spp. remain the most predominant nosocomial fungal infections. Owing to the increased use of antifungal agents, resistance of Candida spp. to antimycotics has emerged frequently, especially to fluconazole (FLC). To cope with this issue, new efforts have been dedicated to discovering novel antimycotics or new agents that can enhance the susceptibility of Candida spp. to existing antimycotics. The secondary metabolites of plants represent a large library of compounds that are important sources for new drugs or compounds suitable for further modification. Research on the anti-Candida activities of phytocompounds has been carried out in recent years and the results showed that a series of phytocompounds have anti-Candida properties, such as phenylpropanoids, flavonoids, terpenoids and alkaloids. Among these phytocompounds, some displayed potent antifungal activity, with minimum inhibitory concentrations (MICs) of ≤8 µg/mL, and several compounds were even more effective against drug-resistant Candida spp. than FLC or itraconazole (e.g. honokiol, magnolol and shikonin). Interestingly, quite a few phytocompounds not only displayed anti-Candida activity alone but also synergised with FLC against Candida spp., even leading to a reversal of FLC resistance. This review focuses on summarising the anti-Candida activities of phytocompounds as well as the interactions of phytocompounds with FLC. In addition, we briefly overview the synergistic mechanisms and present the structure of the antimycotic phytocompounds. Hopefully, this analysis will provide insight into antifungal agent discovery and new approaches against antifungal drug resistance.
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10.
Antifungal Compounds against Candida Infections from Traditional Chinese Medicine.
Liu, X, Ma, Z, Zhang, J, Yang, L
BioMed research international. 2017;:4614183
Abstract
Infections caused by Candida albicans, often refractory and with high morbidity and mortality, cause a heavy burden on the public health while the current antifungal drugs are limited and are associated with toxicity and resistance. Many plant-derived molecules including compounds isolated from traditional Chinese medicine (TCM) are reported to have antifungal activity through different targets such as cell membrane, cell wall, mitochondria, and virulence factors. Here, we review the recent progress in the anti-Candida compounds from TCM, as well as their antifungal mechanisms. Considering the diverse targets and structures, compounds from TCM might be a potential library for antifungal drug development.