ABSTRACT
Phosphatidylinositol (PtdIns) transfer proteins (PITPs) enhance the activities of PtdIns 4-OH kinases that generate signaling pools of PtdIns-4-phosphate. In that capacity, PITPs serve as key regulators of lipid signaling in eukaryotic cells. Although the PITP phospholipid exchange cycle is the engine that stimulates PtdIns 4-OH kinase activities, the underlying mechanism is not understood. Herein, we apply an integrative structural biology approach to investigate interactions of the yeast PITP Sec14 with small-molecule inhibitors (SMIs) of its phospholipid exchange cycle. Using a combination of X-ray crystallography, solution NMR spectroscopy, and atomistic MD simulations, we dissect how SMIs compete with native Sec14 phospholipid ligands and arrest phospholipid exchange. Moreover, as Sec14 PITPs represent new targets for the development of next-generation antifungal drugs, the structures of Sec14 bound to SMIs of diverse chemotypes reported in this study will provide critical information required for future structure-based design of next-generation lead compounds directed against Sec14 PITPs of virulent fungi.
Subject(s)
Antifungal Agents , Drug Design , Phospholipid Transfer Proteins , Saccharomyces cerevisiae Proteins , Biological Transport/drug effects , Phosphatidylinositols/metabolism , Phospholipid Transfer Proteins/antagonists & inhibitors , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/antagonists & inhibitors , Signal Transduction , Antifungal Agents/chemistry , Antifungal Agents/pharmacologyABSTRACT
Sixty-eight morphologically distinct isolates of marine actinomycetes were derived from seashore, mangrove, and saltpan ecosystems located between the Palk Strait and Gulf of Mannar region, Bay of Bengal, Tamilnadu. Twenty-five (36.8%) isolates exhibited anti-mycotic activity against Candida albicans and Cryptococcus neoformans in preliminary screening, and 4 isolates with prominent activity were identified and designated at the genus level as Streptomyces sp. VPTS3-I, Streptomyces sp. VPTS3-2, Streptomyces sp. VPTSA1-4 and Streptomyces sp. VPTSA1-8. All the potential antagonistic isolates were further characterized with phenotypic and genotypic properties including 16S rRNA gene sequencing and identified species level as Streptomyces afghaniensis VPTS3-1, S. matensis VPTS3-2, S. tuirus VPTSA1-4 and S. griseus VPTSA1-8. In addition, the active fractions from the potential antagonistic streptomycetes were extracted with organic solvents by shake flask culture method and the anti-mycotic efficacies were evaluated. The optimization parameters for the production of the anti-mycotic compound were found to be pH between 7 and 8, the temperature at 30áµC, the salinity of 2%, incubation of 9 days, and starch and KNO3 as the suitable carbon and nitrogen sources respectively in starch casein medium.
Subject(s)
Antifungal Agents , Streptomyces , India , Streptomyces/genetics , Streptomyces/metabolism , Antifungal Agents/pharmacology , Soil Microbiology , Candida albicans/drug effects , Cryptococcus neoformans/drug effects , Bays/microbiology , RNA, Ribosomal, 16S/geneticsABSTRACT
INTRODUCTION: Immunosuppression after chemotherapy, stem cell transplantation or solid organ transplantation are the main risk factors for invasive fungal infections in Austria. Here, we aim to describe the status of laboratory mycology and the access to antifungal treatment in Austria. METHODS: Between October and November 2021, hospitals were contacted to participate in our online survey: www.clinicalsurveys.net/uc/IFI_management_capacity/. Centres were required to provide information on their institutional profile; self-assessment of burden of invasive fungal infections; access to microscopy, culture, serology, antigen detection and molecular testing; and availability of antifungal agents and therapeutic drug monitoring. RESULTS: Responses were collected from university hospitals and laboratories in Graz, Innsbruck, Linz and Vienna. The four hospitals can provide tertiary care and were highly specialised, including management of patients with severe immunosuppression. All sites consider the incidence of invasive fungal infections to be moderate. Access to microscopy, culture, serology, antigen detection and molecular testing is provided regardless of laboratory. The maximum capacity to identify fungi varies from institution to institution. All currently marketed antifungal agents are available at the four sites. CONCLUSION: Austria is currently well equipped to deal with the emerging threat of invasive fungal infections. However, hospitals may consider preparing for the potential endemicity of certain infections in the near future.
Subject(s)
Antifungal Agents , Invasive Fungal Infections , Humans , Antifungal Agents/therapeutic use , Austria/epidemiology , Invasive Fungal Infections/diagnosis , Invasive Fungal Infections/drug therapy , Invasive Fungal Infections/epidemiology , Fungi , Health Services AccessibilityABSTRACT
Invasive fungal (IF) diseases are a leading global cause of mortality, particularly among immunocompromised individuals. The SARS-CoV-2 pandemic further exacerbated this scenario, intensifying comorbid IF infections such as mucormycoses of the nasopharynx. In the work reported here, it is shown that zygomycetes, significant contributors to mycoses, are sensitive to the natural product allicin. Inhibition of Mucorales fungi by allicin in solution and by allicin vapor was demonstrated. Mathematical modeling showed that the efficacy of allicin vapor is comparable to direct contact with the commercially available antifungal agent amphotericin B (ampB). Furthermore, the study revealed a synergistic interaction between allicin and the non-volatile ampB. The toxicity of allicin solution to human cell lines was evaluated and it was found that the half maximal effective concentration (EC50) of allicin was 25-72 times higher in the cell lines as compared to the fungal spores. Fungal allicin sensitivity depends on the spore concentration, as demonstrated in a drop test. This study shows the potential of allicin, a sulfur-containing defense compound from garlic, to combat zygomycete fungi. The findings underscore allicin's promise for applications in infections of the nasopharynx via inhalation, suggesting a novel therapeutic avenue against challenging fungal infections.
Subject(s)
Invasive Fungal Infections , Mucorales , Mycoses , Humans , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Mucorales/metabolism , Amphotericin B/pharmacology , Sulfinic Acids/pharmacology , Sulfinic Acids/therapeutic use , Disulfides/pharmacology , Mycoses/drug therapy , Invasive Fungal Infections/drug therapyABSTRACT
Medicinal plant extracts are a promising source of bioactive minor contents. The present study aimed to evaluate the distinguished volatile content of Algerian Cymbopogon citratus (DC.) Stapf before and after the microfluidization process and their related antimicrobial and anti-mycotoxigenic impacts and changes. The GC-MS apparatus was utilized for a comparative examination of Algerian lemongrass essential oil (LGEO) with its microfluidization nanoemulsion (MF-LGEO) volatile content. The MF-LGEO was characterized using Zetasizer and an electron microscope. Cytotoxicity, antibacterial, and antifungal activities were determined for the LGEO and MF-LGEO. The result reflected changes in the content of volatiles for the MF-LGEO. The microfluidizing process enhanced the presence of compounds known for their exceptional antifungal and antibacterial properties in MF-LGEO, namely, neral, geranial, and carvacrol. However, certain terpenes, such as camphor and citronellal, were absent, while decanal, not found in the raw LGEO, was detected. The droplet diameter was 20.76 ± 0.36 nm, and the polydispersity index (PDI) was 0.179 ± 0.03. In cytotoxicity studies, LGEO showed higher activity against the HepG2 cell line than MF-LGEO. Antibacterial LGEO activity against Gram-positive bacteria recorded an inhibitory zone from 41.82 ± 2.84 mm to 58.74 ± 2.64 mm, while the zone ranged from 12.71 ± 1.38 mm to 16.54 ± 1.42 mm for Gram-negative bacteria. Antibacterial activity was enhanced to be up to 71.43 ± 2.54 nm and 31.54 ± 1.01 nm for MF-LGEO impact against Gram-positive and Gram-negative pathogens. The antifungal effect was considerable, particularly against Fusarium fungi. It reached 17.56 ± 1.01 mm and 13.04 ± 1.37 mm for LGEO and MF-LGEO application of a well-diffusion assay, respectively. The MF-LGEO was more promising in reducing mycotoxin production in simulated fungal growth media due to the changes linked to essential compounds content. The reduction ratio was 54.3% and 74.57% for total aflatoxins (AFs) and ochratoxin A (OCA) contents, respectively. These results reflect the microfluidizing improvement impact regarding the LGEO antibacterial, antifungal and anti-mycotoxigenic properties.
Subject(s)
Anti-Infective Agents , Cymbopogon , Oils, Volatile , Antifungal Agents/pharmacology , Anti-Infective Agents/pharmacology , Oils, Volatile/pharmacology , Anti-Bacterial Agents/pharmacologyABSTRACT
BACKGROUND: Antimicrobial prophylaxis is well-accepted in the liver transplant (LT) setting. Nevertheless, optimal regimens to prevent bacterial, viral, and fungal infections are not defined. OBJECTIVES: To identify the optimal antimicrobial prophylaxis to prevent post-LT bacterial, fungal, and cytomegalovirus (CMV) infections, to improve short-term outcomes, and to provide international expert panel recommendations. DATA SOURCES: Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central. METHODS: Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. PROSPERO ID: CRD42021244976. RESULTS: Of 1853 studies screened, 34 were included for this review. Bacterial, CMV, and fungal antimicrobial prophylaxis were evaluated separately. Pneumocystis jiroveccii pneumonia (PJP) antimicrobial prophylaxis was analyzed separately from other fungal infections. Overall, eight randomized controlled trials, 21 comparative studies, and five observational noncomparative studies were included. CONCLUSIONS: Antimicrobial prophylaxis is recommended to prevent bacterial, CMV, and fungal infection to improve outcomes after LT. Universal antibiotic prophylaxis is recommended to prevent postoperative bacterial infections. The choice of antibiotics should be individualized and length of therapy should not exceed 24 hours (Quality of Evidence; Low | Grade of Recommendation; Strong). Both universal prophylaxis and preemptive therapy are strongly recommended for CMV prevention following LT. The choice of one or the other strategy will depend on individual program resources and experiences, as well as donor and recipient serostatus. (Quality of Evidence; Low | Grade of Recommendation; Strong). Antifungal prophylaxis is strongly recommended for LT recipients at high risk of developing invasive fungal infections. The drug of choice remains controversial. (Quality of Evidence; High | Grade of Recommendation; Strong). PJP prophylaxis is strongly recommended. Length of prophylaxis remains controversial. (Quality of Evidence; Very Low | Grade of Recommendation; Strong).
Subject(s)
Anti-Infective Agents , Communicable Diseases , Cytomegalovirus Infections , Liver Transplantation , Mycoses , Pneumonia, Pneumocystis , Humans , Liver Transplantation/adverse effects , Cytomegalovirus Infections/prevention & control , Antibiotic Prophylaxis , Anti-Infective Agents/therapeutic use , Postoperative Complications/prevention & control , Postoperative Complications/drug therapy , Communicable Diseases/drug therapy , Mycoses/drug therapy , Anti-Bacterial Agents/therapeutic useABSTRACT
BACKGROUND: Aspergillus spp. is identified morphologically without antifungal susceptibility tests (ASTs) in most clinical laboratories. The aim of this study was to examine the clinical impact of the morphological identification of Aspergillus spp. to ensure the adequate clinical management of Aspergillus infections. PATIENTS/METHODS: Aspergillus isolates (n = 126) from distinct antifungal treatment-naïve patients with aspergillosis were first identified morphologically, followed by species-level identification via DNA sequencing. An AST for itraconazole (ITC) and voriconazole (VRC) was performed on each Aspergillus isolate. RESULTS: Based on the genetic test results, morphology-based identification was accurate for >95% of the isolates at the species sensu lato level although the test concordance of Aspergillus spp. with low detection rates was low. The rates of cryptic species were found to be 1.2% among the isolates of A. fumigatus complex and 96.8% in the A. niger complex. Cryptic species with lower susceptibilities to antifungal drugs than sensu stricto species among the same Aspergillus section were as follows: The A. lentulus (n = 1) isolates had low susceptibilities to azoles among the A. fumigatus complex species (n = 86), and A. tubingensis isolates (n = 18) exhibited lower susceptibility to azoles among the A. niger complex species (n = 31). CONCLUSION: Diagnostic accuracy was high at the A. fumigatus and A. niger complex level. However, in the presence of cryptic species, a solely morphological identification was insufficient. Particularly, ITC and VRC might be inappropriate for aspergillosis treatment when the A. niger complex is identified morphologically because it is possible that the Aspergillus isolate is A. tubingensis.
Subject(s)
Antifungal Agents , Aspergillosis , Aspergillus/classification , Antifungal Agents/pharmacology , Aspergillosis/diagnosis , Aspergillosis/drug therapy , Aspergillosis/microbiology , Aspergillus/drug effects , Humans , Itraconazole/pharmacology , Microbial Sensitivity Tests , Voriconazole/pharmacologyABSTRACT
Fungal infections of the lung are an increasing problem worldwide and the search for novel therapeutic agents is a current challenge due to emerging resistance to current antimycotics. The volatile defence substance allicin is formed naturally by freshly injured garlic plants and exhibits broad antimicrobial potency. Chemically synthesised allicin was active against selected fungi upon direct contact and via the gas phase at comparable concentrations to the pharmaceutically used antimycotic amphotericin B. We investigated the suppression of fungal growth by allicin vapour and aerosols in vitro in a test rig at air flow conditions mimicking the human lung. The effect of allicin via the gas phase was enhanced by ethanol. Our results suggest that allicin is a potential candidate for development for use in antifungal therapy for lung and upper respiratory tract infections.
Subject(s)
Mycoses , Sulfinic Acids , Disulfides , Humans , Lung , Mycoses/drug therapy , Sulfinic Acids/chemistry , Sulfinic Acids/pharmacology , Sulfinic Acids/therapeutic useABSTRACT
The important physicochemical properties of three novel bioactive hybrid compounds with different groups (-CH3, -F and -Cl) were studied, including kinetic and thermodynamic solubility in pharmaceutically relevant solvents (buffer solutions and 1-octanol) as well as partition coefficient in system 1-octanol/buffer pH 7.4. The aqueous solubility of these chemicals is poor and ranged from 0.67 × 10-4 to 1.98 × 10-3 mol·L-1. The compounds studied are more soluble in the buffer pH 2.0, simulating the gastrointestinal tract environment (by an order of magnitude) than in the buffer pH 7.4 modelling plasma of blood. The solubility in 1-octanol is significantly higher; that is because of the specific interactions of the compounds with the solvent. The prediction solubility behaviour of the hybrid compounds using Hansen's three-parameter approach showed acceptable results. The experimental solubility of potential drugs was successfully correlated by means of two commonly known equations: modified Apelblat and van't Hoff. The temperature dependencies of partition coefficients of new hybrids in the model system 1-octanol/buffer pH 7.4 as a surrogate lipophilicity were measured by the shake flask method. It was found that compounds demonstrated a lipophilic nature and have optimal values of partition coefficients for oral absorption. Bioactive assay manifested that prepared compounds showed antifungal activities equal to or greater than fluconazole. In addition, the thermodynamic aspects of dissolution and partition processes have been examined. Bioactive assay manifested that prepared compounds showed antifungal activities equal to or greater than the reference drug.
Subject(s)
Antifungal Agents , Fluconazole , 1-Octanol/chemistry , Antifungal Agents/pharmacology , Fluconazole/pharmacology , Octanols , Solubility , Solvents/chemistry , Thermodynamics , Water/chemistryABSTRACT
The study aims to assess the interaction between fluconazole and sulfonatocalix[4]naphthalene towards enhancing its dissolution performance and antimycotic activity. A solubility study was carried out at different pH conditions, and the results revealed the formation of a 1:1 molar ratio fluconazole-sulfonatocalix[4]naphthalene inclusion complex with an AL type phase solubility diagrams. The solid powder systems of fluconazole-sulfonatocalix[4]naphthalene were prepared using kneaded and co-evaporation techniques and physical mixtures. DCS, PXRD, TGA-DTG, FT-IR, and in vitro dissolution performance characterize the prepared systems. According to physicochemical characterization, the co-evaporation approach produces an amorphous inclusion complex of the drug inside the cavity of sulfonatocalix[4]naphthalene. The co-evaporate product significantly increased the drug dissolution rate up to 93 ± 1.77% within 10 min, unlike other prepared solid powders. The antimycotic activity showed an increase substantially (p ≤ 0.05, t-test) antimycotic activity of fluconazole co-evaporate mixture with sulfonatocalix[4]naphthalene compared with fluconazole alone against clinical strains of Candida albicans and Candida glabrata. In conclusion, sulfonatocalix[4]naphthalene could be considered an efficient complexing agent for fluconazole to enhance its aqueous solubility, dissolution performance, and antimycotic activity.
Subject(s)
Fluconazole , beta-Cyclodextrins , Calorimetry, Differential Scanning , Fluconazole/pharmacology , Naphthalenes/pharmacology , Powders , Solubility , Spectroscopy, Fourier Transform Infrared , X-Ray Diffraction , beta-Cyclodextrins/chemistryABSTRACT
Dermatophytic infection is a psychological burden due to its inefficacy in prolonged effectiveness during its course of treatment. The present study reports a novel antidermatophytic property from actinomycetes of wetlands soil. Total of 37 Streptomyces isolates were screened for antidermatophytic activity against Trichophyton mentagrophytes. The best isolate with 100% novel activity, was characterized and designated as Streptomyces albidoflavus STV1572a. Antidermatophytic compounds extracted from the mentioned strain were partially purified by chromatographic techniques. Further, it was characterized using UV-Vis spectroscopy, FTIR spectroscopy, and GC-MS analysis. Compound identified were, Phenol 2, 4-bis (1, 1-dimethylethyl), 9-octadecene (E), E-14- Hexadecenal, e-15- Heptadecenal, 1- Heneicosanol, Hypophosphonousdichloride bis (1, 1-dimethylethyl) and Heptadecyl trifluoroacetate. To sum up, this study illustrates an antidermatophytic lead compounds that pave its way for further purification and characterization of these compounds for their optimum utilization for antimycotic purposes.
ABSTRACT
A 5-year-old patient treated for acute lymphoblastic leukaemia (ALL) developed proven pulmonary invasive fungal disease (IFD) due to Actinomucor elegans. While completing ALL treatment according to AIEOP ALL protocol 2009 for further 15 months, antifungal treatment with liposomal amphotericin B and intermittent additional posaconazole was continued until immune reconstitution 7 months after the end of ALL treatment. Repeated imaging guided treatment decisions. Twenty-six and 19 months after the end of ALL treatment and antifungal treatment, respectively, the patient is still in the first complete remission and shows no signs of active invasive fungal disease (IFD).
Subject(s)
Amphotericin B/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Invasive Fungal Infections/drug therapy , Lung Diseases, Fungal/drug therapy , Mucormycosis/drug therapy , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Antifungal Agents/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Asparaginase/administration & dosage , Child, Preschool , Cyclophosphamide/administration & dosage , Cytarabine/administration & dosage , Daunorubicin/administration & dosage , Humans , Lung Diseases, Fungal/microbiology , Male , Mercaptopurine/administration & dosage , Methotrexate/administration & dosage , Mucorales/isolation & purification , Precursor Cell Lymphoblastic Leukemia-Lymphoma/microbiology , Prednisone/administration & dosage , Remission Induction , Triazoles/therapeutic use , Vincristine/administration & dosageABSTRACT
BACKGROUND: Oral follow-up therapy is problematic in moulds with reduced azole-susceptibility, such as azole-resistant Aspergillus fumigatus infection. Currently, only intravenous liposomal amphotericin B (L-AmB) is advocated by guidelines for the treatment of azole-resistant aspergillosis infections. Preclinical research indicates that high-dose posaconazole (HD-POS) might be a feasible option provided that high drug exposure (ie POS serum through levels >3 mg/L) can be achieved and is safe. OBJECTIVES: To describe our experience with the use of oral HD-POS as treatment strategies for patients infected with pathogens with a POS MIC close to the clinical breakpoint. PATIENTS/METHODS: We review evidence supporting the use of HD-POS and describe our experience on safety and efficacy in 16 patients. In addition, we describe the adverse events (AE) observed in 25 patients with POS concentrations at the higher end of the population distribution during treatment with the licensed dose. RESULTS: Sixteen patients were treated intentionally with HD-POS for voriconazole-resistant invasive aspergillosis (7/16), mucormycosis (4/16), salvage therapy for IA (4/16) and IA at a sanctuary site (spondylodiscitis) in 1. Grade 3-4 AEs were observed in 6, and all of them were considered at least possibly related. Grade 3-4 AEs were observed in 5 of the 25 patients with spontaneous high POS serum through levels considered at least possibly related using Naranjo scale. CONCLUSIONS: High-dose posaconazole is a treatment option if strict monitoring for both exposure and for AE is possible.
Subject(s)
Antifungal Agents/therapeutic use , Aspergillosis/drug therapy , Triazoles/therapeutic use , Adolescent , Adult , Aged , Antifungal Agents/administration & dosage , Antifungal Agents/adverse effects , Azoles/pharmacology , Cytochrome P-450 Enzyme System/genetics , Dose-Response Relationship, Drug , Drug Resistance, Fungal , Fungal Proteins/genetics , Humans , Likelihood Functions , Middle Aged , Mutation , Probability , Retrospective Studies , Surveys and Questionnaires , Triazoles/administration & dosage , Triazoles/adverse effectsABSTRACT
The aim of this perspective is to give an overlook on the utility of pharmacokinetics/pharmacodynamics (PK/PD) in predicting the efficacy of antifungals in invasive candidiasis. Overall, from the available literature it appears that bridging data of PK/PD of antifungals from the laboratory to the clinic for the treatment of invasive candidiasis are feasible only partially. Fluconazole is the only antifungal agent having the pharmacodynamic threshold of efficacy identified in experimental animal models convincingly validated in the clinical setting of invasive candidiasis as well. Conversely, for voriconazole and posaconazole data on this topic are very limited. For the echinocandins, robust PK/PD identified in the laboratory represented the rationale for defining differential clinical breakpoints of echinocandins against different species of Candida by the regulatory agencies. However, translation of the findings in the clinical setting provided conflicting results. Data on PK/PD of amphotericin B and flucytosine in models of invasive candidiasis are quite limited, and clinical studies assessing the role of drug exposure on efficacy are currently lacking. The expectation is that prospective studies could test more and more frequently the validity of experimental PK/PD data of antifungals in the clinical setting of invasive candidiasis. The findings could represent a step forward in addressing adequate antifungal stewardship programmes.
Subject(s)
Antifungal Agents , Candida/drug effects , Candidiasis, Invasive/drug therapy , Amphotericin B/pharmacokinetics , Amphotericin B/therapeutic use , Animals , Antifungal Agents/pharmacokinetics , Antifungal Agents/therapeutic use , Antimicrobial Stewardship , Candida albicans/drug effects , Candida glabrata/drug effects , Candida parapsilosis/drug effects , Candida tropicalis/drug effects , Echinocandins/pharmacokinetics , Echinocandins/therapeutic use , Fluconazole/pharmacokinetics , Fluconazole/therapeutic use , Flucytosine/pharmacokinetics , Flucytosine/therapeutic use , Humans , Species Specificity , Triazoles/pharmacokinetics , Triazoles/therapeutic use , Voriconazole/pharmacokinetics , Voriconazole/therapeutic useABSTRACT
OBJECTIVES: Rapid and reliable exclusion of invasive fungal infections (IFI) by markers able to avoid unnecessary empirical antifungal treatment is still a critical unmet clinical need. We investigated the diagnostic performance of a newly available ß-d-Glucan (BDG) quantification assay, focusing on the optimisation of the BDG cut-off values for IFI exclusion. METHODS: BDG results by Wako ß-glucan assay (lower limit of detection [LLOD] = 2.16 pg/mL, positivity ≥ 11 pg/mL) on two consecutive serum samples were retrospectively analysed in 170 patients, admitted to haematological wards (N = 42), intensive care units (ICUs; N = 80), or other wards (N = 48), exhibiting clinical signs and/or symptoms suspected for IFI. Only patients with proven IFI (EORTC/MSG criteria) were considered as true positives in the assessment of BDG sensitivity, specificity and predictive values. RESULTS: Patients were diagnosed with no IFI (69.4%), proven IFI (25.3%) or probable IFI (5.3%). Two consecutive BDG values < LLOD performed within a median of 1 (interquartile range: 1-3) day were able to exclude a proven IFI with 100% sensitivity and negative predictive value (primary study goal). Test's specificity improved by using two distinct positivity and negativity cut-offs (7.7 pg/mL and LLOD, respectively), but remained suboptimal in ICU patients (50%), as compared to haematological or other patients (93% and 90%, respectively). CONCLUSIONS: The classification of Wako's results as negative when < LLOD, and positive when > 7.7 pg/mL, could be a promising diagnostic approach to confidently rule out an IFI in both ICU and non-ICU patients. The poor specificity in the ICU setting remains a concern, due to the difficulty to interpret positive results in this fragile population.
Subject(s)
Diagnostic Tests, Routine/methods , Invasive Fungal Infections/diagnosis , beta-Glucans/blood , Aged , Antifungal Agents/therapeutic use , Caspofungin/therapeutic use , Female , Fluconazole/therapeutic use , Humans , Intensive Care Units , Invasive Fungal Infections/drug therapy , Limit of Detection , Male , Middle Aged , Predictive Value of Tests , Retrospective Studies , Sensitivity and Specificity , Voriconazole/therapeutic useABSTRACT
Nest architecture is a fundamental character shaping immune strategies of social insects. The arboreal ant Temnothorax unifasciatus nests in cavities such as oak galls where the entire colony lives in a unique small chamber. In these conditions, physiological and behavioural strategies likely prevail over compartmentalisation and are presumably tuned with colony size. We designed two experiments to study chemical and behavioural immune strategies against the entomopathogenic fungus Metarhizium anisopliae in colonies of different sizes. First, we compared spore germination and length of germinal tubes inside artificial nests, designed to impede the contact between the ants and the fungus, in colonies of different size. In the absence of direct contact, Temnothorax unifasciatus colonies inhibit fungal growth inside their nests, presumably through volatile compounds. The analysis revealed a positive correlation between fungistatic activity and colony size, indicating that workers of smaller colonies do not invest a higher per capita effort in producing such substances compared to larger colonies. Second, we performed a removal experiment of contaminated and non-contaminated items introduced inside the nests of colonies of different size. Small colonies challenged with contaminated fibres showed an increased removal of all the items (both contaminated and non-contaminated) compared to small colonies challenged with non-contaminated fibres only. Conversely, larger colonies moved items regardless of the presence of the spores inside the nest. Colony size qualitatively affected removal of waste items showing a pathogen elicited reaction in small colonies to optimise the reduced workforce, while the removal behaviour in larger colonies revealed to be expressed constitutively.
Subject(s)
Ants/immunology , Ants/microbiology , Behavior, Animal/physiology , Metarhizium/growth & development , Animals , Plant Tumors/microbiology , Plant Tumors/parasitology , Population Density , Quercus/microbiology , Quercus/parasitologyABSTRACT
A natural and biocompatible extract of garlic as a support, decorated with silver nanoparticles, is a proposal to generate an effective antifungal agent against dermatophytes at low concentrations. Silver nanoparticles (AgNPs) with a diameter of 26±7â nm were synthesized and their antimycotic activity was examined against Trichophyton rubrum (T. rubrum), inhibiting 94 % of growth at a concentration of 0.08â mg ml-1 . Allium sativum (garlic) extract was also obtained (AsExt), and its MIC was 0.04â mg ml-1 . To increase the antifungal capacity of those systems, AsExt was decorated with AgNPs, obtaining AsExt-AgNPs. Using an AsExt concentration of 0.04â mg ml-1 in independent experiments with concentrations from 0.01 to 0.08â mg ml-1 of AgNPs, it was possible to inhibit T. rubrum at all AgNPs concentrations; it proves a synergistic effect between AgNPs and AsExt. Even if 1 % of the minimum inhibitory concentration of AsExt (0.0004â mg ml-1 ) is used, it was possible to inhibit T. rubrum at all concentrations of AgNPs, demonstrating the successful antimycotic activity potentiation when combining AsExt and AgNPs.
Subject(s)
Antifungal Agents/pharmacology , Garlic/chemistry , Nanoparticles/chemistry , Plant Extracts/pharmacology , Silver/pharmacology , Trichophyton/drug effects , Antifungal Agents/chemistry , Antifungal Agents/isolation & purification , Dose-Response Relationship, Drug , Microbial Sensitivity Tests , Molecular Structure , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Silver/chemistry , Structure-Activity RelationshipABSTRACT
Amphotericin B is a lifesaving polyene antibiotic used in the treatment of systemic mycoses. Unfortunately, the pharmacological applicability of this drug is limited because of its severe toxic side effects. At the same time, the lack of a well-defined mechanism of selectivity hampers the efforts to rationally design safer derivatives. As the drug primarily targets the biomembranes of both fungi and humans, new insights into the binding of amphotericin B to lipid membranes can be helpful in unveiling the molecular mechanisms underlying both its pharmacological activity and toxicity. We use fluorescence-lifetime-imaging microscopy combined with fluorescence-emission spectroscopy in the microscale to study the interaction of amphotericin B with single lipid bilayers, using model systems based on giant unilamellar liposomes formed with three lipids: dipalmitoylphosphatidylcholine (DPPC), dimirystoylphosphatidylcholine (DMPC), and 1-palmitoyl-2-oleoylphosphatidylcholine (POPC). The results show that amphotericin B introduced into the water phase as a DMSO solution binds to the membrane as dimers and small-molecular aggregates that we identify as tetramers and trimers. Fluorescence-detected linear-dichroism measurements revealed high orientational freedom of all the molecular-organization forms with respect to the membrane plane, which suggests that the drug partially binds to the membrane surface. The presence of sterols in the lipid phase (cholesterol but particularly ergosterol at 30 mol %) promotes the penetration of drug molecules into the lipid membrane, as concluded on the basis of the decreased orientation angle of amphotericin B molecules with respect to the axis normal to the membrane plane. Moreover, ergosterol facilitates the association of amphotericin B dimers into aggregated structures that can play a role in membrane destabilization or permeabilization. The presence of cholesterol inhibits the formation of small aggregates in the lipid phase of liposomes, making this system a promising candidate for a low-toxicity antibiotic-delivery system. Our conclusions are supported with molecular simulations that reveal the conformational properties of AmB oligomers in both aqueous solution and lipid bilayers of different compositions.
Subject(s)
Amphotericin B/chemistry , Antifungal Agents/chemistry , 1,2-Dipalmitoylphosphatidylcholine/chemistry , Cholesterol/chemistry , Molecular Dynamics Simulation , Phosphatidylcholines/chemistryABSTRACT
The diagnosis of gastrointestinal (GI) mucormycosis is always a challenge due to its non-specific clinical presentations and often diagnosed at autopsy. Recently increased number of GI mucormycosis has been reported in immunocompetent hosts and during 1948 through 2017, 200 cases of GI mucormycosis are available in literature. We could review 176 cases where case details were available. Majority (50.6%) of the cases were reported from Asia. The disease is nearly equally recorded in adults and paediatric population. The infection commonly affected the intestine (64.2%) followed by stomach (33%). A significant improvement in antemortem diagnosis was noted since 2001. Rhizopus species were the predominant (67.5%) aetiological agents. Amphotericin B was the most commonly used drug (93.4%). Despite improvement of antemortem diagnosis and therapy, the mortality was 60.5% and 67.5% in adults and children respectively. Combined medical and surgical therapy (reported in 47.8% patients) had significantly better survival rate than those receiving either of them. Analysing the clinical presentations, we propose to suspect GI mucormycosis in a malnourished/ dehydrated child (especially premature neonate) with history of exposure to broad-spectrum antibiotics or formula/spoon feeding and presenting with mass in abdomen, abdominal distension or bilious vomiting; and an adult presenting with abdominal distension, fever or GI bleed with underlying risk factors for mucormycosis.
Subject(s)
Gastrointestinal Diseases/epidemiology , Mucorales/isolation & purification , Mucormycosis/epidemiology , Adolescent , Adult , Age Distribution , Aged , Antifungal Agents/administration & dosage , Child , Child, Preschool , Female , Gastrointestinal Diseases/microbiology , Gastrointestinal Diseases/pathology , Gastrointestinal Diseases/therapy , Global Health , Humans , Infant , Intestines/microbiology , Intestines/pathology , Male , Middle Aged , Mucorales/classification , Mucormycosis/microbiology , Mucormycosis/pathology , Mucormycosis/therapy , Risk Factors , Stomach/microbiology , Stomach/pathology , Surgical Procedures, Operative/methods , Treatment Outcome , Young AdultABSTRACT
OBJECTIVE: To improve the diagnosis and treatment of Penicilliosis marneffei without human immunodeficiency virus infection. METHODS: Analyze and review the clinical features, diagnosis and treatment of six cases of P. marneffei without human immunodeficiency virus infection at The First Affiliated Hospital of Fujian Medical University. RESULTS: Two cases were diagnosed in the ENT Department, three cases in the respiratory department and one case in the dermatological department. Penicillium marneffei infection was confirmed by sputum culture, blood culture and tissue biopsy. After definite diagnosis, one refused further treatment, and others showed significant improvement. CONCLUSION: Penicilliosis marneffei is insidious onset and easy to be escaped and misdiagnosed. To achieve early diagnosis and appropriate treatment, doubtful cases should be alerted for the diagnoses as P. marneffei.