Molecular epidemiology of aspergillosis in Magellanic penguins and susceptibility patterns of clinical isolates.

Aspergillus section Fumigati is reported in up to 99% of aspergillosis cases in penguins. So far, no data regarding molecular epidemiology and azole resistance are available for A. fumigatus isolates collected from Magellanic penguins. The aim of this work was to perform molecular identification of Aspergillus section Fumigati at species level, to genotype those isolates using microsatellite markers, to evaluate the in vitro susceptibility patterns of A. fumigatus sensu stricto, and to characterize the cyp51A gene in clinical A. fumigatus strains isolated from Magellanic penguins with proven aspergillosis. All 34 isolates included in the study were identified as A. fumigatus sensu stricto. Analyzing the genetic diversity of the isolates of A. fumigatus sensu stricto, we identified two possible outbreaks in the rehabilitation center and we also observed the maintenance of clonal strains through the years. One A. fumigatus sensu stricto isolate was resistant to posaconazole, but the mutations found in the cyp51A gene of this isolate have not been described as conferring phenotypic resistance, suggesting that other mechanisms of resistance could be involved in the resistance of this isolate. With this study, we were able to understand the molecular diversity of Aspergillus fumigatus isolates collected from Magellanic penguins, to characterize them and to associate them with the described global population of Aspergillus fumigatus.

A. fumigatus sensu stricto is of great importance in penguins' aspergillosis. We could identify two outbreaks in the rehabilitation center and the maintenance of clonal strains through the years. Regarding antifungal prophylaxis, it may proceed, but preferably with surveillance for azole resistance.

Aerosol Inhalation Delivery of Triazavirin in Mice: Outlooks for Advanced Therapy Against Novel Viral Infections.

Under pandemic-caused emergency, evaluation of the potential of existing antiviral drugs for the treatment of COVID-19 is relevant. Triazavirin, an antiviral drug developed in Russia for per-oral administration, is involved in clinical trials against SARS-CoV-2 coronavirus. This virus has affinity to epithelial cells in respiratory tract, so drug delivery directly in lungs may enhance therapeutic effect and reduce side effects for stomach, liver, kidneys. We elaborated ultrasonic method of triazavirin aerosol generation and investigated the inhalation delivery of this drug in mice. Mean particle size and number concentration of aerosol used in inhalation experiments are 560 nm and 4 × 105 cm-3, respectively. Aerosol mass concentration is 1.6 × 10-4 mg/cm3. Inhalation for 20 min in a nose-only chamber resulted in 2 mg/kg body delivered dose and 2.6 µg/mL triazavirin concentration in blood plasma. Elimination rate constant determined in aerosol administration experiments was ke = 0.077 min-1, which agrees with the value measured after intravenous delivery, but per-oral administration resulted in considerably lower apparent elimination rate constant of pseudo-first order, probably due to non-linear dependence of absorption rate on triazavirin concentration in gastrointestinal tract. The bioavailability of triazavirin aerosol is found to be 85%, which is about four times higher than for per-oral administration.

A comprehensive review on environmental toxicity of azole compounds to fish.

BACKGROUND: Azoles are considered as one of the most efficient fungicides for the treatment of humans, animals, and plant fungal pathogens. They are of significant clinical importance as antifungal drugs and are widely used in personal care products, ultraviolet stabilizers, and in aircraft for its anti-corrosive properties. The prevalence of azole compounds in the natural environment and its accumulation in fish raises questions about its impact on aquatic organisms. OBJECTIVES: The objective of this paper is to review the scientific studies on the effects of azole compounds in fish and to discuss future opportunities for the risk evaluation. METHODS: A systematic literature search was conducted on Web of Science, PubMed, and ScienceDirect to locate peer-reviewed scientific articles on occurrence, environmental fate, and toxicological impact of azole fungicides on fish. RESULTS: Studies included in this review provide ample evidence that azole compounds are not only commonly detected in the natural environment but also cause several detrimental effects on fish. Future studies with environmentally relevant concentrations of azole alone or in combination with other commonly occurring contaminants in a multigenerational study could provide a better understanding. CONCLUSION: Based on current knowledge and studies reporting adverse biological effects of azole on fish, considerable attention is required for better management and effective ecological risk assessment of these emerging contaminants.

N-Trifluoromethyl Amines and Azoles: An Underexplored Functional Group in the Medicinal Chemist's Toolbox.

Introducing trifluoromethyl groups is a common strategy to improve the properties of biologically active compounds. However, N-trifluoromethyl moieties on amines and azoles are very rarely used. To evaluate their suitability in drug design, we synthesized a series of N-trifluoromethyl amines and azoles, determined their stability in aqueous media, and investigated their properties. We show that N-trifluoromethyl amines are prone to hydrolysis, whereas N-trifluoromethyl azoles have excellent aqueous stability. Compared to their N-methyl analogues, N-trifluoromethyl azoles have a higher lipophilicity and can show increased metabolic stability and Caco-2 permeability. Furthermore, N-trifluoromethyl azoles can serve as bioisosteres of N-iso-propyl and N-tert-butyl azoles. Consequently, we suggest that N-trifluoromethyl azoles are valuable substructures to be considered in medicinal chemistry.

Efficacy of curcumin in the treatment of experimental vulvovaginal candidiasis / Eficacia de la curcumina en el tratamiento de la candidiasis vulvovaginal experimental

Background: Candida albicans is the main agent that causes vulvovaginal candidiasis. Resistance among isolates to azole antifungal agents has been reported. Aims: Due to the well-known antifungal potential of curcumin, the purpose of this work was to evaluate the in vitro anticandidal activity of curcumin and its effect in the treatment of experimental vulvovaginal candidiasis. Methods: The anticandidal activity of curcumin was investigated against eight Candida strains by the broth microdilution assay, and its mechanism of action was evaluated by testing the binding to ergosterol. Then, the effect of curcumin in the treatment of vulvovaginal candidiasis was evaluated in an immunosuppressed, estrogen treated rat model. Results: Curcumin showed minimum inhibitory concentration values of 125-1000μg/ml, and the best result was observed against Candida glabrata. The compound was shown to be able to bind to the ergosterol present in the membrane, event that may be the mechanism of action. In addition, in the in vivo model of vulvovaginal candidiasis with C. albicans, treatments reduced the vaginal fungal burden in infected rats after seven days of treatment with different doses. Conclusions: Curcumin could be considered a promising effective antifungal agent in the treatment of vulvovaginal candidiasis

Antecedentes: Candida albicans es la principal causante de la candidiasis vulvovaginal y algunos aislamientos pueden presentar resistencia a los antifúngicos azólicos. Objetivos: Debido al conocido potencial antifúngico de la curcumina, el objetivo de este trabajo fue evaluar su actividad anti-Candidain vitro y su efecto en el tratamiento de la candidiasis vulvovaginal experimental. Métodos: La actividad anti-Candida de la curcumina se evaluó frente a ocho cepas de Candida mediante un ensayo de microdilución en caldo, y su mecanismo de acción se estudió por una prueba de unión a ergosterol. Posteriormente se evaluó el efecto de la curcumina en el tratamiento de la candidiasis vulvovaginal con un modelo de rata inmunosuprimida, tratada con estrógenos. Resultados: La curcumina mostró valores de concentración inhibitoria mínima de 125-1.000μg/ml, y el mejor resultado se observó frente a Candida glabrata. El compuesto demostró ser capaz de unirse al ergosterol de la membrana, lo que podría ser su mecanismo de acción. Además, en el modelo in vivo de candidiasis vulvovaginal con C. albicans, los tratamientos redujeron la carga fúngica vaginal en ratas infectadas después de siete días de tratamiento con diferentes dosis. Conclusiones: La curcumina podría considerarse un agente antifúngico eficaz prometedor en el tratamiento de la candidiasis vulvovaginal

Efecto inhibitorio del dietilestilbestrol sobre aislamientos clínicos de Candida albicans sensibles y resistentes a los azoles / Inhibitory effect of diethylstilbestrol on clinical strains of Candida albicans susceptible and resistant to azoles

Antecedentes: Candida albicans es uno de los microorganismos más frecuentemente involucrados en diversas infecciones; la cavidad bucal del paciente, los nichos de caries o la enfermedad periodontal pueden actuar en ocasiones como reservorio. El desarrollo de resistencia a los medicamentos disponibles y otros factores justifican la búsqueda de nuevos antimicóticos. Objetivos: Estudiar de forma comparativa los efectos in vitro del medicamento antitumoral dietilestilbestrol (DES) y del fluconazol (FLZ) sobre el crecimiento de cepas clínicas de C. albicans aisladas de pacientes con enfermedades odontológicas y médicas. Métodos: Se emplearon siete cepas de C. albicans: a) la cepa de colección ATCC 90028, sensible a FLZ (ATCC); b) cuatro aislamientos bucales de sendas pacientes oncológicas con enfermedad periodontal (period 8, 9, 10 y 11); y c) dos aislamientos bucales de un paciente con sida y candidiasis orofaríngea: un aislamiento era sensible a FLZ (2-76) y el otro resistente (12-99). Se evaluó el crecimiento celular por técnicas espectrofotométricas estandarizadas (M27-A3, CLSI) y se calculó la concentración inhibitoria 50% (CI50) por análisis de funciones mediante el programa Graph Pad. Resultados: El DES inhibió el crecimiento de C. albicans, tanto sensible como resistente al FLZ. Los datos se ajustan adecuadamente a curvas teóricas saturables de tipo concentración del inhibidor versus respuesta. Las concentraciones inhibitorias mínimas fueron con DES y FLZ, respectivamente, las siguientes: 28,18µg/ml y 4,90µg/ml (ATCC); 17,16µg/ml y 3,14µg/ml (period); 27,64µg/ml y 4,22µg/ml (2-76); 6,16µg/ml y 438,19µg/ml (12-99). Conclusiones: El DES tiene actividad antimicótica sobre aislamientos de C. albicans de pacientes con enfermedades odontológicas y médicas. La mayor potencia antimicótica observada fue sobre el aislamiento resistente al FLZ

Background: Candida albicans is a microorganism frequently involved in several infections; the patient's oral cavity, caries niches or periodontal disease can sometimes be the reservoir.. The fungal resistance to the available treatments, among other reasons, has led to the search for new antifungal alternatives. Aims: To carry out a comparative study of the in vitro effects of diethylstilboestrol (DES) and fluconazole (FLZ) on the growth of clinical strains of C. albicans. Methods: Seven strains of C. albicans were used: a) one FLZ-sensitive culture collection strain, ATCC 90028 (ATCC); b) four oral isolates from four oncological patients with periodontal disease (period 8, 9, 10, and 11); and c) two oral isolates from an AIDS patient with oropharyngeal candidiasis: one FLZ- sensitive (2-76), and another FLZ- resistant (12-99). The MIC was evaluated by standard spectrophotometric techniques using the CLSI (M27-A3) guidelines. The inhibitory concentration 50% (IC50) was calculated using functional analysis with the Graph Pad software. Results: DES inhibited the growth of all C. albicans strains, whether sensitive or resistant to FLZ. Experimental data fitted non-linear functions of inhibitor concentration versus response. Minimum inhibitory concentrations (MIC) for DES and FLZ were as follows: 28.18µg/ml and 4.90µg/ml (ATCC); 17.16µg/ml and 3.14µg/ml (period); 27.64µg/ml and 4.22µg/ml (2-76); 6.16µg/ml and 438.19µg/ml (12-99), respectively. Conclusions: DES showed antifungal activity on all clinical C. albicans strains isolated from patients with dental and medical diseases. It showed the highest potency on the FLZ-resistant isolate

Prediction of tacrolimus dosage in the early period after heart transplantation: a population pharmacokinetic approach.

AIM: The aim of this study was to evaluate tacrolimus population pharmacokinetics and investigate factors that explain tacrolimus variability in adult heart transplant patients. METHODS: A total of 707 tacrolimus concentrations from 107 adult heart transplant patients were included in model development. The effects of demographic, clinical factors and CYP3A5 genotype on tacrolimus clearance were evaluated using a nonlinear mixed-effects modeling. 24 patients with 106 tacrolimus concentrations were used for external validation. RESULTS: The pharmacokinetic data were adequately described by a one-compartment model with first-order absorption and elimination. The estimated apparent clearance and volume of distribution of tacrolimus were 13.7 l/h and 791 l, respectively. Tacrolimus apparent clearance was significantly reduced in CYP3A5 nonexpressers (CYP3A5*3/*3), concomitant with azole antifungal drugs and Wuzhi capsule (WZ). A predictive performance was further confirmed in an external validation by Bayesian estimation. Recommended dose regimens were obtained by simulations based on the established model. CONCLUSION: This is the first population pharmacokinetic study conducted in Chinese heart transplant recipients. These findings are of great importance with regards to tacrolimus dose optimization in heart transplantation patients.

Integrating anatomo-physiological changes and pharmacogenomics in anti-infective therapy management: is it a major concern?

Success of anti-infective therapy is a major challenge in some patients given anatomo-physiological changes and genetic variations. In this case anecdote, we report the management strategy of a patient suffering from chronic pulmonary aspergillosis in a context of anorexia nervosa and genetic polymorphism.

The impact of azole antifungal drugs on imatinib metabolism in human liver microsomes.

1. Imatinib is widely used for the treatment of hematologic malignancies. It is common that imatinib is clinically co-prescribed with azole antifungal agents since these patients are more prone to invasive antifungal infection. The present study was to investigate the effects of azole antifungal drugs, including ketoconazole, fluconazole, voriconazole, itraconazole and posaconazole on imatinib metabolism. 2. The main metabolites, 1-OH midazolam and N-desmethyl imatinib, were determined in the absence and in the presence of various levels of ketoconazole, fluconazole, voriconazole, itraconazole and posaconazole. The relevant assay was also performed to screen mechanism-based inhibitors (MBI). 3. The inhibition ability of 1-OH midazolam formation from midazolam based on IC50 values was ketoconazole (0.09 µM)>itraconazole (0.31 µM)> posaconazole (0.68 µM)>voriconazole (2.10 µM) > fluconazole (8.90 µM). Similarly, the rank order of inhibitory effects on formation of N-desmethyl imatinib from imatinib was ketoconazole (4.58 µM)>itraconazole (17.45 µM)> posaconazole (31.02 µM)> voriconazole (367.9 µM) >fluconazole (1.11 mM). Posaconazole and itraconazole displayed evidence of MBI. Additionally, imatinib was also shown as a MBI of CYP3A with IC50 value of 5.40 µM against the midazolam. 4. The significant difference in IC50 values of midazolam and imatinib inhibited by azole antifungal agents was observed. The role of CYP2C8 in imatinib metabolism and imatinib autoinhibits CYP3A activity may explain this difference. Our findings suggest that the azole antifungal agents might have limited impacts on imatinib exposure by CYP3A activity.

18F-Flortanidazole Hypoxia PET Holds Promise as a Prognostic and Predictive Imaging Biomarker in a Lung Cancer Xenograft Model Treated with Metformin and Radiotherapy.

Metformin may improve tumor oxygenation and thus radiotherapy response, but imaging biomarkers for selection of suitable patients are still under investigation. First, we assessed the effect of acute metformin administration on non-small cell lung cancer xenograft tumor hypoxia using PET imaging with the hypoxia tracer 18F-flortanidazole. Second, we verified the effect of a single dose of metformin before radiotherapy on long-term treatment outcome. Third, we examined the potential of baseline 18F-flortanidazole as a prognostic or predictive biomarker for treatment response. Methods: A549 tumor-bearing mice underwent a 18F-flortanidazole PET/CT scan to determine baseline tumor hypoxia. The next day, mice received a 100 mg/kg intravenous injection of metformin. 18F-flortanidazole was administered intravenously 30 min later, and a second PET/CT scan was performed to assess changes in tumor hypoxia. Two days later, the mice were divided into 3 therapy groups: controls (group 1), radiotherapy (group 2), and metformin + radiotherapy (group 3). Animals received saline (groups 1-2) or metformin (100 mg/kg; group 3) intravenously, followed by a single radiotherapy dose of 10 Gy (groups 2-3) or sham irradiation (group 1) 30 min later. Tumor growth was monitored triweekly by caliper measurement, and tumor volume relative to baseline was calculated. The tumor doubling time (TDT), that is, the time to reach twice the preirradiation tumor volume, was defined as the endpoint. Results: Thirty minutes after metformin treatment, 18F-flortanidazole demonstrated a significant change in tumor hypoxia, with a mean intratumoral reduction in 18F-flortanidazole tumor-to-background ratio (TBR) from 3.21 ± 0.13 to 2.87 ± 0.13 (P = 0.0001). Overall, relative tumor volume over time differed across treatment groups (P < 0.0001). Similarly, the median TDT was 19, 34, and 52 d in controls, the radiotherapy group, and the metformin + radiotherapy group, respectively (log-rank P < 0.0001). Both baseline 18F-flortanidazole TBR (hazard ratio, 2.0; P = 0.0004) and change from baseline TBR (hazard ratio, 0.39; P = 0.04) were prognostic biomarkers for TDT irrespective of treatment, and baseline TBR predicted metformin-specific treatment effects that were dependent on baseline tumor hypoxia. Conclusion: Using 18F-flortanidazole PET imaging in a non-small cell lung cancer xenograft model, we showed that metformin may act as a radiosensitizer by increasing tumor oxygenation and that baseline 18F-flortanidazole shows promise as an imaging biomarker.

A Novel, Rapid, and Low-Volume Assay for Therapeutic Drug Monitoring of Posaconazole and Other Long-Chain Azole-Class Antifungal Drugs.

Clinicians need a better way to accurately monitor the concentration of antimicrobials in patient samples. In this report, we describe a novel, low-sample-volume method to monitor the azole-class antifungal drug posaconazole, as well as certain other long-chain azole-class antifungal drugs in human serum samples. Posaconazole represents an important target for therapeutic drug monitoring (TDM) due to its widespread use in treating invasive fungal infections and well-recognized variability of pharmacokinetics. The current "gold standard" requires trough and peak monitoring through high-pressure liquid chromatography (HPLC) or liquid chromatography-tandem mass spectroscopy (LC-MS/MS). Other methods include bioassays that use highly susceptible strains of fungi in culture plates or 96-well formats to monitor concentrations. Currently, no method exists that is both highly accurate in detecting free drug concentrations and is also rapid. Herein, we describe a new method using reduced graphene oxide (rGO) and a fluorescently labeled aptamer, which can accurately assess clinically relevant concentrations of posaconazole and other long-chain azole-class drugs in little more than 1 h in a total volume of 100 µl.IMPORTANCE This work describes an effective assay for TDM of long-chain azole-class antifungal drugs that can be used in diluted human serum samples. This assay will provide a quick, cost-effective method for monitoring concentrations of drugs such as posaconazole that exhibit well-documented pharmacokinetic variability. Our rGO-aptamer assay has the potential to improve health care for those struggling to treat fungal infections in rural or resource-limited setting.

Are In Vitro Susceptibilities to Azole Antifungals Predictive of Clinical Outcome in the Treatment of Candidemia?

The purpose of this review is to critically analyze published data evaluating the impact of azole pharmacokinetic and pharmacodynamic parameters, MICs, and Candida species on clinical outcomes in patients with candidemia. Clinical breakpoints (CBPs) for fluconazole and voriconazole, which are used to determine susceptibility, have been defined by the Clinical and Laboratory Standards Institute (CLSI) for Candida species. Studies evaluating the relationship between treatment efficacy and in vitro susceptibility, as well as the pharmacodynamic targets, have been conducted in patients treated with fluconazole for candidemia; however, for species other than Candida albicans and Candida glabrata, and for other forms of invasive candidiasis, data remain limited and randomized trials are not available. Limited data evaluating these relationships with voriconazole are available. While pharmacodynamic targets for posaconazole and isavuconazole have been proposed based upon studies conducted in murine models, CBPs have not been established by CLSI. Fluconazole remains an important antifungal agent for the treatment of candidemia, and data supporting its use based on in vitro susceptibility are growing, particularly for C. albicans and C. glabrata Further investigation is needed to establish the roles of voriconazole, posaconazole, and isavuconazole in the treatment of candidemia and for all agents in the treatment of other forms of invasive candidiasis.

Isavuconazole: A new broad-spectrum azole. Part 2: pharmacokinetics and clinical activity.

Isavuconazole, the active moiety of its prodrug isavuconazonium, is a new extended-spectrum triazole whose activity against yeasts, molds, including Aspergillus and mucorales, and dimorphic fungi has been shown in vitro and in preclinical models. The most relevant pharmacokinetics features are water-solubility of the prodrug, rapid cleavage of the prodrug into active moiety and cleavage product by plasmatic esterases, high oral bioavailability of isavuconazole with an extensive penetration into most tissues and a good safety profile even in case of renal impairment. The results of two main clinical studies have led to an approval by FDA and EMA in the treatment of invasive aspergillosis and invasive mucormycosis. Isavuconazole is non-inferior to voriconazole in terms of response and survival in invasive aspergillosis and has shown improved safety and tolerability. Importantly, less hepatobiliary, skin and eye disorders have been reported in isavuconazole-treated patients. Isavuconazole has therefore been granted a grade A-I recommendation by the European Conference on Infections in Leukemia (ECIL) for the treatment of invasive aspergillosis. Efficacy has also been demonstrated in mucormycosis in an open-label study. Survival was similar to the survival of matched patients from the international Fungiscope registry and treated with an amphotericin B formulation. Isavuconazole failed to show non-inferiority to caspofungin in a large double-blind candidemia trial. The aim of this review is to give the reader an overview of the data available so far to support inclusion of isavuconazole in the anti-mold therapeutic arsenal.

Pharmacokinetics of Azole Antifungals in Cystic Fibrosis.

Defects in mucociliary clearance predispose cystic fibrosis (CF) patients to airway colonization and infection by various fungi, especially Aspergillus fumigatus. Although the clinical significance of airway fungal colonization is not clear, several studies have suggested its association with worsening lung function and increased risk of CF exacerbations. Antifungal triazole agents have been used in CF patients with airway fungal colonization or infections with varying results. Limited pharmacokinetic studies to date have demonstrated high inter-subject variability of triazole levels among CF patients. This review discusses the basic principles of pharmacokinetics, the pharmacokinetic changes associated with CF and the effect of CF on the pharmacokinetic principles of azole antifungals. The inconsistent azole serum levels in CF patients may be associated with sub-therapeutic (thus risk of therapeutic failure and/or emergence of azole-resistant fungi) or supratherapeutic exposures (thus potential risk of azole toxicity), suggesting that therapeutic dose monitoring is necessary in CF patients.

Actividad antifúngica in vitro de azoles y anfotericina B frente a Malassezia furfur por el método de microdilución M27-A3 del CLSI y Etest® / In vitro antifungal activity of azoles and amphotericin B against Malassezia furfur by the CLSI M27-A3 microdilution and Etest® methods

Antecedentes. Malassezia furfur es una levadura comensal de la piel del ser humano que ha sido asociada con la presencia de algunas entidades dermatológicas e infecciones sistémicas oportunistas. Por su condición dependiente de lípidos, los métodos de referencia establecidos para las levaduras por el Clinical and Laboratory Standards Institute (CLSI) para evaluar la sensibilidad antifúngica no son aplicables. Objetivos. Evaluar la sensibilidad in vitro de aislamientos de M. furfur asociados a procesos patológicos en el ser humano frente a antifúngicos de uso clínico. Métodos. Se evaluó el perfil de sensibilidad a la anfotericina B, el itraconazol, el ketoconazol y el voriconazol de 20 aislamientos de M. furfur mediante el método de microdilución en caldo (CLSI M27-A3) y Etest®. Resultados. El itraconazol y el voriconazol presentaron la mayor actividad antifúngica frente a los aislamientos evaluados. El acuerdo esencial entre los dos métodos usados para evaluar la actividad antifúngica de los azoles estuvo en el 60-85%, y el acuerdo categórico en el 70-80%; para la anfotericina B tanto el acuerdo esencial como el categórico fueron del 10%. Conclusiones. De acuerdo con los dos métodos evaluados los azoles fueron los compuestos que presentaron la mayor actividad antifúngica frente a M. furfur; sin embargo, es necesario realizar más estudios que permitan afirmar que Etest® es un método confiable para ser implementado en la rutina del laboratorio clínico (AU)

Background. Malassezia furfur is a human skin commensal yeast that can cause skin and opportunistic systemic infections. Given its lipid dependant status, the reference methods established by the Clinical and Laboratory Standards Institute (CLSI) to evaluate antifungal susceptibility in yeasts are not applicable. Aims. To evaluate the in vitro susceptibility of M. furfur isolates from infections in humans to antifungals of clinical use. Methods. The susceptibility profile to amphotericin B, itraconazole, ketoconazole and voriconazole of 20 isolates of M. furfur, using the broth microdilution method (CLSI M27-A3) and Etest®, was evaluated. Results. Itraconazole and voriconazole had the highest antifungal activity against the isolates tested. The essential agreement between the two methods for azoles antifungal activity was in the region of 60-85% and the categorical agreement was around 70-80%, while the essential and categorical agreement for amphotericin B was 10%. Conclusions. The azoles were the compounds that showed the highest antifungal activity against M. furfur, as determined by the two techniques used; however more studies need to be performed to support that Etest® is a reliable method before its implementation as a routine clinical laboratory test (AU)

In vitro bioaccessibility of copper azole following simulated dermal transfer from pressure-treated wood.

Micronized copper azole (MCA) and micronized copper quaternary (MCQ) are the latest wood preservatives to replace the liquid alkaline copper and chromated copper arsenate preservatives due to concerns over the toxicity or lack of effectiveness of the earlier formulations. Today, the use of MCA has become abundant in the wood preservative industry with approximately 38millionlbs of copper carbonate being used to treat lumber each year. Despite this widespread usage, little information is available on the bioaccessibility of this preservative upon gastrointestinal exposure. Using a simulated hand-to-mouth/gastric system exposure study we investigated several types of commercially available copper-treated lumber products as-purchased and after exposure to outdoor weathering conditions. Soluble and particulate fractions of copper were measured after transfer to and release from surface wipes passed along copper-treated lumber and exposed to synthetic stomach fluid (SSF, pH1.5) or deionized (DI) water. Wipes passed along new boards contained greater amounts of copper than wipes from weathered boards. The total copper recovered from the wipes after microwave extraction varied among the different wood types. For all wood types the copper released into SSF was more soluble than what was soluble in DI water. The data suggest that copper from treated wood is highly bioaccessible in SSF regardless of wood type and weathering condition.

Antifungal pharmacodynamics: Latin America's perspective

Abstract The current increment of invasive fungal infections and the availability of new broad-spectrum antifungal agents has increased the use of these agents by non-expert practitioners, without an impact on mortality. To improve efficacy while minimizing prescription errors and to reduce the high monetary cost to the health systems, the principles of pharmacokinetics (PK) and pharmacodynamics (PD) are necessary. A systematic review of the PD of antifungals agents was performed aiming at the practicing physician without expertise in this field. The initial section of this review focuses on the general concepts of antimicrobial PD. In vitro studies, fungal susceptibility and antifungal serum concentrations are related with different doses and dosing schedules, determining the PD indices and the magnitude required to obtain a specific outcome. Herein the PD of the most used antifungal drug classes in Latin America (polyenes, azoles, and echinocandins) is discussed.

Antifungal pharmacodynamics: Latin America's perspective.

The current increment of invasive fungal infections and the availability of new broad-spectrum antifungal agents has increased the use of these agents by non-expert practitioners, without an impact on mortality. To improve efficacy while minimizing prescription errors and to reduce the high monetary cost to the health systems, the principles of pharmacokinetics (PK) and pharmacodynamics (PD) are necessary. A systematic review of the PD of antifungals agents was performed aiming at the practicing physician without expertise in this field. The initial section of this review focuses on the general concepts of antimicrobial PD. In vitro studies, fungal susceptibility and antifungal serum concentrations are related with different doses and dosing schedules, determining the PD indices and the magnitude required to obtain a specific outcome. Herein the PD of the most used antifungal drug classes in Latin America (polyenes, azoles, and echinocandins) is discussed.

Pharmacodynamics of Voriconazole against Wild-Type and Azole-Resistant Aspergillus flavus Isolates in a Nonneutropenic Murine Model of Disseminated Aspergillosis.

Invasive aspergillosis (IA) due to Aspergillus flavus is associated with high mortality. Although voriconazole (VRC) is widely recommended as the first-line treatment for IA, emergence of azole resistance in Aspergillus spp. is translating to treatment failure. We evaluated the efficacy of voriconazole in a nonneutropenic murine model of disseminated A. flavus infection using two voriconazole-resistant isolates (one harboring the Y319H substitution in the cyp51C gene) and two wild-type isolates without mutations. All isolates exhibited a dose-response relationship, and voriconazole treatment improved mouse survival in a dose-dependent manner. At 40 mg/kg of body weight, 100% efficacy was observed for 1 susceptible isolate and 1 resistant isolate (with mutation), whereas for another susceptible isolate and resistant isolate (without mutation), survival rates were 81% and 72%, respectively. The Hill equation with a variable slope fitted the relationship between the area under the concentration-time curve (AUC)/MIC ratio and 14-day survival well for each strain. An F test showed the 50% effective doses to be significantly different from each other (P = 0.0023). However, contrary to expectation, there was a significant difference in exposure-response relationships between strains, and it appeared that the susceptible strains required a relatively higher exposure than the resistant ones to result in the same treatment effect, the 50% effective pharmacokinetic/pharmacodynamic (PK/PD) index (EI50) required being negatively and log-linearly related to the MIC (P = 0.04). We conclude that the efficacy of voriconazole depended on drug exposure and the voriconazole MIC of the isolates, but lower exposures are required for strains with higher MICs. These findings may have profound significance in clinical practice with respect to dosing and drug choice.