Synergistic In Vitro Interaction of Isavuconazole and Isoquercitrin against Candida glabrata.

In vitro interactions of broad-spectrum azole isavuconazole with flavonoid isoquercitrin were evaluated by a broth microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference methodology for antifungal susceptibility testing against 60 Candida strains belonging to the species Candida albicans (n = 10), Candida glabrata (n = 30), Candida kefyr (n = 6), Candida krusei (n = 5), Candida parapsilosis (n = 4), and Candida tropicalis (n = 5). The results were analyzed with the fractional inhibitory concentration index and by response surface analysis based on the Bliss model. Synergy was found for all C. glabrata strains, when the results were interpreted by the fractional inhibitory concentration index, and for 60% of the strains when response surface analysis was used. Interaction for all other species was indifferent for all strains tested, whatever interpretation model used. Importantly, antagonistic interaction was never observed.

In Vitro Synergy of Isavuconazole Combined With Colistin Against Common Candida Species.

Interactions of isavuconazole and colistin were evaluated against 57 common Candida strains belonging to the species Candida albicans (n = 10), Candida glabrata (n = 10), Candida kefyr (n = 8), Candida krusei (n = 10), Candida parapsilosis (n = 9), and Candida tropicalis (n = 10) by a broth microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference methodology for antifungal susceptibility testing. Results were analyzed with the fractional inhibitory concentration index and by the response surface analysis. Interpretation by the fractional inhibitory concentration index showed synergy for 50%, 80%, 90%, and 90% of the C. kefyr, C. krusei, C. glabrata, and C. tropicalis strains, respectively. Combination of isavuconazole with colistin against C. albicans and C. parapsilosis exhibited only indifference for 100% and 90% of the strains, respectively. The results were confirmed by response surface analysis for all species except for C. glabrata, for which an indifferent interaction was found for the majority of strains. Antagonistic interaction was never seen regardless of the interpretation model was used.

In Vitro Activity of Amphotericin B in Combination with Colistin against Fungi Responsible for Invasive Infections.

The in vitro interaction of amphotericin B in combination with colistin was evaluated against a total of 86 strains comprising of 47 Candida species (10 Candida albicans, 15 Candida auris, five Candida glabrata, three Candida kefyr, five Candida krusei, four Candida parapsilosis and five Candida tropicalis), 29 Aspergillus species (five Aspergillus flavus, 10 Aspergillus fumigatus, four Aspergillus nidulans, five Aspergillus niger, and five Aspergillus terreus), and 10 Rhizopus species (seven Rhizopus arrhizus, one Rhizopus delemar and two Rhizopus microsporus) strains. For the determination of the interaction, a microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference method for antifungal susceptibility testing was used. Results of the checkerboard technique were evaluated by the fractional inhibitory concentration index (FICI) based on the Loewe additivity model for all isolates. Different inhibition endpoints were used to capture both the interaction at MIC and sub-MIC levels. Additionally, checkerboard technique results for Candida species were evaluated by response surface analysis based on the Bliss independence model. Against common Candida species, the combination was synergistic for 75% of the strains by FICI and for 66% of the strains by response surface analysis. For C. tropicalis, the interaction was antagonistic for three isolates by FICI, but antagonism was not confirmed by response surface analysis. Interestingly, synergistic and antagonistic FICIs were simultaneously present on checkboard microplates of all three strains. Against C. auris the combination was synergistic for 73% of the strains by response surface analysis and for 33% of the strains by FICI. This discrepancy could be related to the insensitivity of the FICI to detect weak interactions. Interaction for all other strains was indifferent. For Aspergillus and Rhizopus species combination exhibited only indifferent interactions against all tested strains.

Carbodiimide-fueled catalytic reaction cycles to regulate supramolecular processes.

Using molecular self-assembly, supramolecular chemists can create Gigadalton-structures with angstrom precision held together by non-covalent interactions. However, despite relying on the same molecular toolbox for self-assembly, these synthetic structures lack the complexity and sophistication of biological assemblies. Those assemblies are non-equilibrium structures that rely on the constant consumption of energy transduced from the hydrolysis of chemical fuels like ATP and GTP, which endows them with dynamic properties, e.g., temporal and spatial control and self-healing ability. Thus, to synthesize life-like materials, we have to find a reaction cycle that converts chemical energy to regulate self-assembly. We and others recently found that this can be done by a reaction cycle that hydrates carbodiimides. This feature article aims to provide an overview of how the energy transduced from carbodiimide hydration can alter the function of molecules and regulate molecular assemblies. The goal is to offer the reader design considerations for carbodiimide-driven reaction cycles to create a desired morphology or function of the assembly and ultimately to push chemically fueled self-assembly further towards the bottom-up synthesis of life.

In Vitro Antifungal Combination of Terbinafine with Itraconazole against Isolates of Trichophyton Species.

Terbinafine is used as the first-line therapy for dermatophytosis, but the incidence of terbinafine resistance is increasing. A combination of terbinafine with itraconazole was tested using the checkerboard method based on the EUCAST methodology for antifungal susceptibility testing against 9 terbinafine-susceptible and 7 terbinafine-resistant clinical isolates of Trichophyton spp. from India. Synergistic interactions were observed for 4/9 of the susceptible isolates, with fractional inhibitory concentration index (FICI) values of 0.3125 to 0.5, and for 4/7 of the resistant isolates, with FICI values of 0.032 to 0.3125.

Droplet Formation by Chemically Fueled Self-Assembly: The Role of Precursor Hydrophobicity.

We investigate active droplets that form at the expense of a chemical fuel in aqueous buffer and vanish autonomously. Dynamic light scattering reveals the scattered intensity, the hydrodynamic radius, and the width of the size distribution with high precision as well as high temporal and spatial resolutions. Comparing the resulting time-dependent behavior of the droplet characteristics with the time-dependent concentration of the anhydrides, the roles of the chemical reaction cycle and of colloidal growth processes are elucidated. The droplet sizes and lifetimes depend strongly on the hydrophobicity of the precursor, and the growth rate is found to correlate with the deactivation rate of the product.

Chemically fueled materials with a self-immolative mechanism: transient materials with a fast on/off response.

There is an increasing demand for transient materials with a predefined lifetime like self-erasing temporary electronic circuits or transient biomedical implants. Chemically fueled materials are an example of such materials; they emerge in response to chemical fuel, and autonomously decay as they deplete it. However, these materials suffer from a slow, typically first order decay profile. That means that over the course of the material's lifetime, its properties continuously change until it is fully decayed. Materials that have a sharp on-off response are self-immolative ones. These degrade rapidly after an external trigger through a self-amplifying decay mechanism. However, self-immolative materials are not autonomous; they require a trigger. We introduce here materials with the best of both, i.e., materials based on chemically fueled emulsions that are also self-immolative. The material has a lifetime that can be predefined, after which it autonomously and rapidly degrades. We showcase the new material class with self-expiring labels and drug-delivery platforms with a controllable burst-release.

Parasitic behavior in competing chemically fueled reaction cycles.

Non-equilibrium, fuel-driven reaction cycles serve as model systems of the intricate reaction networks of life. Rich and dynamic behavior is observed when reaction cycles regulate assembly processes, such as phase separation. However, it remains unclear how the interplay between multiple reaction cycles affects the success of emergent assemblies. To tackle this question, we created a library of molecules that compete for a common fuel that transiently activates products. Often, the competition for fuel implies that a competitor decreases the lifetime of these products. However, in cases where the transient competitor product can phase-separate, such a competitor can increase the survival time of one product. Moreover, in the presence of oscillatory fueling, the same mechanism reduces variations in the product concentration while the concentration variations of the competitor product are enhanced. Like a parasite, the product benefits from the protection of the host against deactivation and increases its robustness against fuel variations at the expense of the robustness of the host. Such a parasitic behavior in multiple fuel-driven reaction cycles represents a lifelike trait, paving the way for the bottom-up design of synthetic life.

Techniques for the Assessment of In Vitro and In Vivo Antifungal Combinations.

Systemic fungal infections are associated with high mortality rates despite adequate treatment. Moreover, acquired resistance to antifungals is increasing, which further complicates the therapeutic management. One strategy to overcome antifungal resistance is to use antifungal combinations. In vitro, several techniques are used to assess drug interactions, such as the broth microdilution checkerboard, agar-diffusion methods, and time-kill curves. Currently, the most widely used technique is the checkerboard method. The aim of all these techniques is to determine if the interaction between antifungal agents is synergistic, indifferent, or antagonistic. However, the interpretation of the results remains difficult. Several methods of analysis can be used, based on different theories. The most commonly used method is the calculation of the fractional inhibitory concentration index. Determination of the usefulness of combination treatments in patients needs well-conducted clinical trials, which are difficult. It is therefore important to study antifungal combinations in vivo, in experimental animal models of fungal infections. Although mammalian models have mostly been used, new alternative animal models in invertebrates look promising. To evaluate the antifungal efficacy, the most commonly used criteria are the mortality rate and the fungal load in the target organs.

In vitro synergy of isavuconazole in combination with colistin against Candida auris.

The in vitro interactions of isavuconazole with colistin were evaluated against 15 clinical Candida auris isolates by a microdilution checkerboard technique based on the EUCAST reference method for antifungal susceptibility testing and by agar diffusion using isavuconazole gradient concentration strips with or without colistin incorporated RPMI agar. Interpretation of the checkerboard results was done by the fractional inhibitory concentration index and by response surface analysis based on the Bliss model. By checkerboard, combination was synergistic for 93% of the isolates when interpretation of the data was done by fractional inhibitory concentration index, and for 80% of the isolates by response surface analysis interpretation. By agar diffusion test, although all MICs in combination decreased compared to isavuconazole alone, only 13% of the isolates met the definition of synergy. Essential agreement of EUCAST and gradient concentration strip MICs at +/- 2 log2 dilutions was 93.3%. Antagonistic interactions were never observed for any technique or interpretation model used.

Colistin and Isavuconazole Interact Synergistically In Vitro against Aspergillus nidulans and Aspergillus niger.

The in vitro interactions of isavuconazole in combination with colistin were evaluated against 55 clinical Aspergillus species isolates belonging to the five most important species (Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus niger, and Aspergillus terreus) responsible for human aspergillosis by a microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference method for antifungal susceptibility testing. Selected isolates (A. nidulans, n = 10; A. niger, n = 15) were additionally evaluated by an agar diffusion assay using isavuconazole gradient concentration strips with or without colistin incorporated Roswell Parc Memorial Institute (RPMI) agar. Interpretation of the checkerboard results was done by the fractional inhibitory concentration index. Using the checkerboard method, combination isavuconazole-colistin was synergistic for 100% of the 15 A. nidulans isolates and for 60% of the 20 A. niger isolates. No interactions were found for any of the other isolates. By agar diffusion assay, minimal inhibitory concentrations (MICs) in combination decreased compared to isavuconazole alone for 92% of the isolates. No interactions were found for any A. nidulans isolates, but synergy was observed for 40% of the A. niger isolates. A poor essential agreement of EUCAST and gradient concentration strip MICs at ± 2 log2 dilutions with 0% was obtained. Antagonistic interactions were never observed regardless of the technique used.

In Vitro Interaction between Isavuconazole and Tacrolimus, Cyclosporin A, or Sirolimus against Aspergillus Species.

The interaction of isavuconazole with immunosuppressors (tacrolimus, cyclosporin A, or sirolimus) against 30 Aspergillus isolates belonging to the most common species responsible for invasive aspergillosis in humans (Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus niger, and Aspergillus terreus) was evaluated in vitro by a microdilution checkerboard technique based on the EUCAST reference method for antifungal susceptibility testing. The interpretation of the results was performed based on the fractional inhibitory concentration index. The combination of isavuconazole with tacrolimus, cyclosporin A, or sirolimus, was synergistic for 56, 20, or 10% of the isolates, respectively. Interestingly synergy of the combination of isavuconazole with tacrolimus was also achieved for the majority of azole-resistant isolates of A. fumigatus, and for all A. niger isolates with isavuconazole minimal inhibitory concentrations ≥ 8 µg/mL. Antagonistic interactions were never observed for any combination tested.

Evaluation of the Gradient Concentration Strip Method for Antifungal Susceptibility Testing of Isavuconazole and Comparators for Mucorales Species.

MIC values for amphotericin B and three azoles determined by the EUCAST reference technique and by gradient concentration strips were compared for 30 Mucorales isolates belonging to clinically important species. Essential agreement (EA) within ±2 dilution steps at 24 hours between the techniques was 83.3% for isavuconazole. EAs for itraconazole, amphotericin B, and posaconazole were 86.7%, 73.3%, and 56.7%, respectively. A good agreement was obtained between visual and spectrophotometric readings for EUCAST.

Identification of Mucorales by Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry.

More than 20 different species of Mucorales can be responsible for human mucormycosis. Accurate identification to the species level is important. The morphological identification of Mucorales is not reliable, and the currently recommended identification standard is the molecular technique of sequencing the internal transcribed spacer regions. Nevertheless, matrix-assisted laser desorption ionization time-of-flight mass spectrometry has been shown to be an accurate alternative for the identification of bacteria, yeasts, and even filamentous fungi. Therefore, 38 Mucorales isolates, belonging to 12 different species or varieties, mainly from international collections, including 10 type or neo-type strains previously identified by molecular methods, were used to evaluate the usefulness of matrix-assisted laser desorption ionization time-of-flight mass spectrometry for the identification of human pathogenic Mucorales to the species level. One to three reference strains for each species were used to create a database of main spectrum profiles, and the remaining isolates were used as test isolates. A minimum of 10 spectra was used to build the main spectrum profile of each database strain. Interspecies discrimination for all the isolates, including species belonging to the same genus, was possible. Twenty isolates belonging to five species were used to test the database accuracy, and were correctly identified to the species level with a log-score >2. In summary, matrix-assisted laser desorption ionization time-of-flight mass spectrometry is a reliable and rapid method for the identification of most of the human pathogenic Mucorales to the species level.

In vitro interactions between isavuconazole and tacrolimus, cyclosporin A or sirolimus against Mucorales.

OBJECTIVES: To evaluate the in vitro interactions of isavuconazole with immune suppressors (tacrolimus, cyclosporin A or sirolimus) against 30 Mucorales isolates belonging to the most common species responsible for mucormycosis in humans (Rhizopus arrhizus, Rhizopus delemar, Rhizopus microsporus, Lichtheimia corymbifera, Lichtheimia ramosa, Mucor circinelloides and Rhizomucor pusillus). METHODS: In vitro interaction was evaluated by a microdilution chequerboard technique. RESULTS: Combination of isavuconazole with tacrolimus, cyclosporin A or sirolimus, was synergistic for 50%, 46% and 7% of the isolates, respectively. Antagonistic interaction was observed for 4% of the isolates for the combination with cyclosporin A (one R. arrhizus isolate) and for 32% of the isolates for the combination with sirolimus (six R. arrhizus isolates and three R. pusillus isolates). CONCLUSIONS: These in vitro data show that calcineurin inhibitors are more likely than inhibitors of the mTOR pathway to enhance the activity of isavuconazole against Mucorales. These in vitro results warrant further animal experiments.

Antifungal combinations in Mucorales: A microbiological perspective.

Mucormycosis mostly affects immunocompromised patients and is associated with a high morbidity and mortality despite currently available treatments. In that context, combination therapy might be the key to a better outcome for these patients. Purpose of this review is to summarise and to discuss the current combination data obtained in vitro, in vivo in animal models of mucormycosis, and in patients. In vitro combination studies showed that most of the interactions between antifungal drugs were indifferent, even though that some synergistic interactions were achieved for the combination of echinocandins with either azoles or amphotericin B. Importantly, antagonism was never observed. Animal models of mucormycosis focused on infections caused by Rhizopus arrhizus, neglecting most other species responsible for human disease. In these experimental animal models, no strong interactions have been demonstrated, although a certain degree of synergism has been reported in some instances. Combinations of antifungals with non-antifungal drugs have also been largely explored in vitro and in animal models and yielded interesting results. In patients with ketoacidosis and rhino-orbito-cerebral infection, combination of polyene with caspofungin was effective. In contrast, despite promising experimental data, adjunctive therapy with the iron chelator deferasirox was unfavourable and was associated with a higher mortality than monotherapy with liposomal amphotericin B. More combinations have to be tested in vitro and a much larger panel of Mucorales species has to be tested in vivo to give a valuable statement if antifungal combination therapy could be an effective treatment strategy in patients with mucormycosis.

COPD as a risk factor of the complications in lower limb arthroplasty: a patient-matched study.

Purpose: A relevant proportion of patients undergoing joint replacement surgery for the treatment of osteoarthritis exhibit COPD. This coincidence may result from an increased prevalence of both the diseases in elderly patients. In this study, COPD, which is known to be associated with a variety of comorbidities, and its potential interactions, eg, mediated via systemic inflammation, are discussed. The purpose of the present study was to identify the role of COPD as an independent risk factor for complications after total knee and hip arthroplasty. Patients and methods: In a monocentric patient cohort of 2,760 arthoplasties, propensity score matching was done using the following factors: sex, age, replaced joint, American Society of Anesthesiologists' score, body mass index, hypertension, chronic heart disease, anticoagulation, diabetes mellitus, chronic renal deficiency, and actual smoking status to create 224 pairs. Both the pre-matched differences and the results after propensity score matching were statistically analyzed with p≤0.05 being defined as statistically significant. Results: All confounders were eliminated after matching. Preoperatively measured C-reactive protein and leukocytes were higher in the COPD group (p<0.001; p=0.01, respectively). Intensive care unit admission was higher for COPD patients (p=0.023). Pneumonia occurred in patients with COPD only (p=0.024). There was a trend (not significant) toward a higher rate of wound infections, increased transfusion of red blood cells, and a prolonged hospital stay in patients with COPD. Conclusion: COPD was associated with an increased length of hospital stay, a higher risk of pneumonia and wound infection, higher general complications, and an increased need for red blood cell transfusion. It is thus recommended to enhance the implementation of pneumonia prevention programs on surgical wards.

Molecular identification of fungi found on decomposed human bodies in forensic autopsy cases.

To investigate which fungi can be found during forensic autopsies, a PubMed literature review was done in regard to fungal growth on decomposed human bodies. Unfortunately, the existing data is limited and not all fungi were identified to the species level. We, therefore, collected skin samples with macroscopically visible fungal growth from 23 autopsy cases in Germany and identified the fungi to the species level by molecular methods. The identified species included Aspergillus fumigatus and Candida albicans, which pose an allergenic risk, especially to persons with underlying lung diseases. Because safety standards are lacking, we recommend the use of respiratory protection during exhumations and forensic autopsies, when fungal growth is noted. With regard to the future, a database was set up which could possibly be used as a forensic tool to determine the time of death.

Effects of a best-possible-self mental imagery exercise on mood and dysfunctional attitudes.

Dispositional optimism has been related to positive physical and mental health outcomes, increased positive mood ratings and cognitions about the future. In order to determine the causal relation between optimism and mood and cognitions optimism should be manipulated experimentally. The current study tested the effects of a best-possible-self mental imagery exercise on affect and mood ratings and dysfunctional cognitions following a sad mood induction in undergraduate students (N=40). Participants in the experimental condition wrote about their best possible self in the future for 15 min and engaged in a mental imagery task about their best possible self in the future for 5 min in order to experimentally induce optimism. Participants in the control condition wrote about a typical day for 15 min and engaged in mental imagery about a typical day for 5 min. We assessed affect, mood and dysfunctional cognitions before and after the experimental manipulation. Participants in the experimental condition had higher positive mood ratings and higher positive affect compared to participants in the control condition. Participants in the control condition reported decreased dysfunctional cognitions whereas dysfunctional cognitions in the experimental group remained unchanged. Future studies should replicate these findings in clinical groups with more profound levels of negative affect and dysfunctional cognitions.