Amphotericin B intercalated in layered clays as effective antifungal systems against eumycetoma causative agents.

Objective To analyze the distribution, diversity, and the sensitivity of common pathogen species to antifungal drugs in fungal keratitis during 2000 - 2006 in Shandong province. Methods Samples from corneal serapings and corneal buttons from keratoplasties were used for fungal culture and identification. The distribution and diversity of the pathogens in different years were analyzed. The sensitivity of some common species to antifungal drugs were tested. Results A total of 898 patients were diagnosed as fungal keratitis, in which 770 (85.7%) were positive in fungal culture. Pathogens in 748 cases caused by fungal infection were identified, of which 547 cases were caused by Fusarium (71.0%). The prevelence of Fusarium from 2000 to 2006 was 75.5%, 72.8%, 71.5%, 75.2%, 76%, 68. 8% and 56.4% respectively. Eighty-four cases were caused by Aspergillus( 10.9% ) , which accounted for 15.1% , 15.2% , 13.1%, 10. 2%, 10. 4% , 8.0% and 6. 9% of the cases from 2000 to 2006, respectively. Seventy-four eases were caused by Alternaria (9. 6% ), the percentage of which during 2000 -2006 was 1. 9%, 3.3%, 3.7%, 6. 6%, 8. 8%, 12. 0 and 29. 7% respectively. In genus Fusarium, 10 species were found and the most common species were Fusarium Solani ( 33. 8% ), Fusarium oxysporum ( 28.2% ) and Fusarium moniliforme( 27.4% ). Six species were identified in genus Aspergillus, with Aspergillus flavus (53.6%) and Aspergillus fumigatus (39.3% ) being the most common species. The geometric mean MICs of amphotericin B, terbinafin, itraconazole, 5-flucytosine and fluconazole against the common species were 0. 647, 0. 714, 1. 624, 15. 108 and 27. 070 μg/ml, respectively. The mean MICs of the above five antifungal drugs against Fusarium were 0. 899, 0. 893, 3.077, 37. 124 and 21. 687 μg/ml, respectively, and for Aspergillus, the mean MICs of these agents were 0.794, 0.591, 0.416, 23.973 and 7.127 μg/ml, respectively; for Alternaria,the MICs were 0. 409,0. 479,0. 433,11. 655 and 7. 104 μg/ml ,respectively. Conclusions Genus Fusarium, Aspergillus and Alternaria were the predominant pathogens in fungal keratitis in Shandong Province. During 2000 -2006, Fusarium was the most common one, followed by Aspergillus. The percentage of Aspergillus decreased annually. The third most common pathogen, Alternaria increased during the period. The geometric mean MICs of amphotericin B and terbinafin against Fusarium were lower than those of itraconazole, 5-flucytosine and fluconazole. The MICs of these five anti-fungal drugs against Aspergillus and Alternatia were lower than those for Fusarium. Key words: Keratitis; Eye infections,fungal; Microbial sensitivity tests

Fungaemia caused by Malassezia spp. in hospitalized patients requires prompt and appropriate therapy, but standard methods for the definition of the in vitro antifungal susceptibility have not been established yet. In this study, the in vitro susceptibility of Malassezia furfur from bloodstream infections (BSIs) to amphotericin B (AMB), fluconazole (FLC), itraconazole (ITC), posaconazole (POS) and voriconazole (VRC) was assessed using the broth microdilution (BMD) method of the Clinical and Laboratory Standards Institute (CLSI) with different media such as modified Sabouraud dextrose broth (SDB), RPMI and Christensen's urea broth (CUB). Optimal broth media that allow sufficient growth of M. furfur, and produce reliable and reproducible MICs using the CLSI BMD protocol were assessed. Thirty-six M. furfur isolates collected from BSIs of patients before and during AMB therapy, and receiving FLC prophylaxis, were tested. A good growth of M. furfur was observed in RPMI, CUB and SDB at 32 °C for 48 and 72 h. No statistically significant differences were detected between the MIC values registered after 48 and 72 h incubation. ITC, POS and VRC displayed lower MICs than FLC and AMB. These last two antifungal drugs showed higher and lower MICs, respectively, when the isolates were tested in SDB. SDB is the only medium in which it is possible to detect isolates with high FLC MICs in patients receiving FLC prophylaxis. A large number of isolates showed high AMB MIC values regardless of the media used. In conclusion, SDB might be suitable to determine triazole susceptibility. However, the media, the drug formulation or the breakpoints herein applied might not be useful for assessing the AMB susceptibility of M. furfur from BSIs.

Chlorinated phenoxyacetic acid herbicides, such as 2,4-dichlorophenoxyacetic acid（2,4-D）, are widely used for controling weeds. Due to its low pKa value of 2.73, 2,4-D exists as an anionic species in the environment and has high mobility in soils and can easily migrate to non-target area by leaching. Layered double hydroxides (LDHs) have high specific surface area and anionic exchange capacity (AEC), so they have high potential in immobilizing inorganic and organic anion contaminants in water. However the adsorption is not specific to 2,4-D, and the existences of other anions may lower the adsorption efficiency of LDHs for 2,4-D. A better understanding of the adsorption mechanisms of LDHs will be essential for selective removal of 2,4-D by LDHs from water. In this study, the effects of the positive charge density and nitrate orientation of LDHs on the adsorption of 2,4-D were investigated. Mg/Al-NO3 LDH with Al3+/(Mg2++Al3+) molar ratios of 1/3 (LDH3), 1/4 (LDH4), 1/5(LDH5) were synthesized and used as the adsorbents. The kinetic study showed that the adsorption could reach equilibrium in 10 minutes. Among the samples, LDH3 has the highest layer charge density and contains nitrate with an orientation perpendicular to the hydroxide sheets, so the maximum adsorption of 2,4-D on LDH3 was as high as 89% of its anionic exchange capacity. The 2,4-D adsorption of LDH3 occurred mainly through ion exchange for interlayer nitrate. On the contrary, LDH5 with a low 2,4-D adsorption capacity due to the low accessibility of 2,4-D to the interlayer space. The accessibility was restricted by the small basal spacing of LDH5 as a result of the parallel orientation of the interlayer nitrate with respect to the hydroxide sheet. Thus, the 2,4-D adsorption occurred mainly on the external surface of the material, and the maximum adsorption of 2,4-D on LDH5 was 16 ％ of its anionic exchange capacity. For LDH4 that contains interlayer nitrate with both parallel and perpendicular orientations, the adsorption characteristics was between those of LDH3 and LDH5, and the maximum amount of 2,4-D adsorbed on LDH4 was 66% of the anionic exchange capacity. The results of competitive adsorption revealed that the adsorptions of 2,4-D on LDH3 and LDH4 are less affected by the coexistences of other anions, such as Cl-、Br 、NO3-、HCO3-、SO42-, in solution. The kinetic adsorption curves of LDH3 and LDH4 in different temperatures had a good fit with pseudo-second order kinetic model. The rate of the adsorption of 2,4-D on LDHs increasing with temperature, and LDH3 required more activation energy to adsorb 2,4-D then LDH4. The results of this study suggested that LDH3 is a better adsorbent for removing 2,4-D from water.

Since its discovery, amphotericin B (AmB) became a key management because it is the most common antifungal drug with activity to disrupt the fungal cell wall. Furthermore, it is the first-choice treatment in pulmonary mycoses that may consider lethal infection; the difference in lipid structure between fungal and mammalian cell membranes determines the effect of AmB. However, some fungal pulmonary diseases such as aspergillomas are partially contact with the blood and narrow touch the walls of the lung cavities, thus administration of systemic antifungal agents may be ineffective to eliminate these infections. Tissue penetration of systemic antifungal agents must be evaluated to get a proper appreciation of their antifungal activity, which may differ even within the same antifungal class. So, topical administration considered necessity in these situations. AmB belongs to the polyene group has a wide-spectrum in vitro and in vivo antifungal activity. All of the known available formulas of AmB are administrated through intravenous injection to treat severe systemic fungal infections, while the development of the topical formula of AmB is still under preliminary development, including topical pulmonary AmB. Due to the revealing of antimicrobial-resistant fungi in recent years and ineffective systemic management of pulmonary fungi, this study explains the role of topical AmB in treating refractory lung fungi that not response to other drugs that may help researchers to develop an effective topical formula of AmB regarding pulmonary mycosis.

Background:An increase in the number of immunocompromised patients has led to a rising burden of systemic fungal infections. Historically, conventional amphotericin B has been used to treat these infections due to its broad spectrum of activity. The development of lipid-based amphotericin B agents, such as Abelcet (ABLC), has allowed clinicians to take advantage of the broad spectrum of activity of amphotericin B while reducing adverse events. As well as this, a number of new antifungal agents have been developed in recent years which have significantly added to the treating physician’s antifungal armamentarium.* Abelcet is a registered trade name of Cephalon Ltd, Herts, UK.Objectives:Review the clinical data that support the use of ABLC and discuss the evidence for its continuing role in the treatment of invasive fungal infections in light of the introduction of newer antifungal agents.Methods:Published studies were identified by searching the MEDLINE database and the Cochrane Centre for Reviews up to August 2009. The search was conducted using the following key words: Amphotericin, Lipid, Abelcet, AmBisome, Efficacy, Nephrotoxicity, Renal, Toxicity.Findings:ABLC is effective and well-tolerated in the treatment of systemic fungal infections and remains a valuable therapeutic option in a variety of immunocompromised patients due to its broad antifungal spectrum and rarity of resistance.Limitations:Data from randomised controlled trials of lipid-based amphotericin B formulations, as well as head-to-head comparison studies between ABLC and other antifungal agents are limited. In addition, the review uses a narrative approach and relies to a great extent on the authors’ personal views and experiences.

PurposeFungal central nervous system (CNS) infections show a high mortality rate and only a few antifungal agents are available to treat these infections. We hypothesize that the different biochemical properties of human cerebrospinal fluid (CSF) compared to the standard growth medium lead to the altered activity of antifungal agents in CSF. We investigated the in vitro activity of two of these agents, i.e., amphotericin B (AmB) and voriconazole (VOR), against three different fungi in CSF in comparison to sabouraud-dextrose broth (SDB).MethodsCSF samples from patients who did not receive any antibiotics were collected. Time-kill curves were performed in CSF and SDB using static antibiotic concentrations of AmB and VOR against ATCC strains of Candida albicans, Candida krusei, and Cryptococcus neoformans.ResultsIn our experiments, both AmB and VOR showed superior activity in SDB compared to CSF. Nevertheless, AmB achieved fungicidal activity in CSF after 24 h against all test strains. Voriconazole only achieved fungistatic activity against C. albicans and C. neoformans in CSF.ConclusionsIn summary, our data demonstrate that growth of fungal pathogens but even more importantly activity of antifungal agents against Candida and Cryptococcus species can differ significantly in CSF compared to the standard growth medium. Both findings should be taken into consideration when applying PK/PD simulations to fungal infections of the CNS.

Invasive fungal infections have been an increasingly global issue with high mortality. Amphotericin B (AmB), as the "gold standard" antifungal drug, has broad-spectrum antifungal activity and low clinical resistance. Therefore, AmB is the most commonly used polyene antibiotic for the treatment of invasive fungal infections. However, the serious side effects as well as the low bioavailability of AmB strongly restrict its clinical applications. Polymer, with its diversified molecular design, is widely used in drug delivery in the form of polymeric prodrugs, nanoparticles, hydrogels, etc. Therefore, polymers hold great promise for the delivery of AmB in treating fungal infections. This review summarizes recent advances in polymer-based delivery systems of AmB for the treatment of fungal infections, including polymer-AmB conjugates, nanotechnology-based polymeric delivery systems, hydrogels, and polymeric microneedles. Taking advantage of polymer-based delivery strategies, special attention is paid to reducing the side effects and improving the bioavailability of AmB for safe and effective antifungal therapy. Finally, the limitations and possible future directions of polymer-based AmB delivery systems are discussed.

Arsenate adsorption by Mg/Al–NO 3 layered double hydroxides with varying the Mg/Al ratio

Medical Costs Analysis for Antifungal Prophylaxis in Neutropenic Patients with Hematological Malignancies: A Systematic Review Analysis.

The influence of an antioxidant, propyl gallate (PG), on the activity of amphotericin B (AMB), terbinafine (TBF), butenafine (BTF) and ketoconazole (KCZ) against ocular pathogenic filamentous fungi in vitro was investigated to determine whether PG could increase the antifungal activity. Susceptibility tests were performed against 6 isolates of ocular pathogenic filamentous fungi (Fusarium solanae, Fusarium moniliforme, Fusarium poae, Fusarium oxysporum, Aspergillus fumigatus and Aspergillus flavus) and 2 quality control strains (Candida krusei ATCC 6258 and Cadida parapsilosis ATCC 22019) by the NCCLS M38-P broth microdilution method (MIC). PG was added to the incubation media at a final concentration of 400 microg/ml. Antifungal agents were serially two-fold diluted and final dilutions were made in 1640 and PG-1640 culture media to a concentration ranging from 0.0313 to 16 microg/ml for AMB, TBF, BTF and KCZ. One hundred microl of the corresponding diluted inoculum suspension was added to each well of the microdilution tray. The MIC end-point of AMB was determined as 100% growth reduction and the MIC end-point of TBF, BTF, KCZ and PG was determined as 75% growth reduction as compared with the turbidity produced by the control well. At a concentration of 400 microg/ml, PG did not show any antifungal activity under these experimental conditions. The combination of PG (400 microg/ml) with amphotericin B revealed a remarkably increased activity against all of the isolates of ocular pathogenic filamentous fungi and quality control strains. In the combination of PG with terbinafine, a remarkably increased activity was observed against Fusarium solanae, Fusarium poae, Fusarium oxysporum, Aspergillus fumigatu and Aspergillus flavus. The combination of PG with butenafine had remarkably synergistic effect against Fusarium solanae, but did not synergistic or even showed antagonistic effect for other isolates. The combination of PG with ketaconazole was synergistic against Fusarium solanae, but was antagonistic against all other isolates. Combination of PG and amphotericin has remarkably synergistic effect against all tested ocular pathogenic filamentous fungi isolates. Combination of PG and terbinafine has remarkably synergistic effect against some isolates. The PG-amphotericin combination and the PG-terbinafine combination may have a role in future studies of antifungal eye drops.

Spherical multilammelar vesicles of liposome consisting of lipid egg phosphatidylcholine, soya lecithin and cholesterol were prepared by thin film hydration technique. Further liposomal gel was prepared by egg phosphatidylcholine and cholesterol of molar ratio 7:3 and attained slow drug release with Allicin- Amphotericin B liposomal based gels as compared to the plane gel. Liposomal gel was characterized for drug release kinetics, antifungal activity (disc diffusion assay). Formulation F8 A shows highest drug release. Allicin (Allium sativum Linn.) showed a minimum inhibitory concentration (MIC) at the dose range from 0.195 µg/ml to 10 µg/ml of broth against all fungal strains (F2B Formulation). These lower concentrations were achievable for fungistatic effect and the reduced adverse effects. The results suggest that liposomal gel of Amphotericin B may be useful in the treatment of Topical Fungal Infections.

Fungal infections are often associated with prolonged hospital stay and high mortality, and are costly to the healthcare system. The incidence of fungal infections has increased in tandem with the growing number of immunocompromised patients in recent years, underlining the need for novel antifungal agents. The 2000s were the most prolific decade for the development of antifungal drugs, with the introduction of newer triazoles (voriconazole, posaconazole) and echinocandins (caspofungin, micafungin, anidulafungin), providing a wider choice of treatment options. These newer antifungal agents, however, are much more expensive, and thus, significantly increase hospital drug expenditure. Relative health returns of these high-cost alternatives need to be determined given that healthcare services have limited resources. Accordingly, this thesis was geared towards deriving critical information to facilitate decision making by the healthcare providers in optimising the use of these high-cost antifungal agents for the prophylaxis and treatment of fungal infections. Three main areas were explored: voriconazole prophylaxis in lung transplant (LTx) recipients, cost-effective use of echinocandins in treating candidaemia and invasive candidiasis (IC) and the potential use of caspofungin eye drops for the treatment of fungal keratitis. Within the context of antifungal prophylaxis in lung transplantation, there is no consensus with respect to the choice of agent and strategy due to the paucity of data. An anonymous web-based survey was conducted to determine antifungal prophylactic practice in LTx centres world-wide. Findings from the survey indicated that voriconazole was the most commonly used agent for both universal and pre-emptive prophylaxis within the first six months post-LTx. A retrospective, single-centre, observational study was then undertaken to investigate the efficacy and safety of voriconazole pre-emptive prophylaxis in 62 LTx recipients. Six months after initiation of voriconazole prophylaxis, the majority (75.8%) had successful eradication of fungal colonisation; one patient developed proven fungal infection. Sixteen (25.8%) had died by 12 months after commencing prophylaxis, half due to Bronchiolitis Obliterans Syndrome. Chronic rejection within the 30 days prior to voriconazole prophylaxis was significantly associated with mortality at the 6-month and 12-month end-points. Ten patients (16.1%) had drug-related hepatotoxicity. The second focus was to determine the cost-effectiveness of echinocandins compared to other antifungal agents in treating candidaemia and IC. Accordingly, pharmacoeconomic comparisons between echinocandins (caspofungin, micafungin, anidulafungin), liposomal amphotericin B (LAmB) and fluconazole in the Australian setting were conducted. The comparisons employed decision analytical models based on treatment pathways derived from published randomised clinical trials, and utilised expert panels from Australia. Analyses were from a hospital perspective and cost inputs were obtained from the latest Australian resources. The robustness of the economic models was evaluated by sensitivity analyses. Hospitalisation was revealed as the major cost driver. Anidulafungin was a cost-effective option compared to fluconazole, with an incremental cost-effectiveness ratio of AU$22,003 per life-year saved. Micafungin was expected to have a total net cost-saving of AU$10,957 per patient over LAmB, whereas it was cost-equivalent to caspofungin, with variation in drug acquisition cost likely to be a critical factor. The final aim was to investigate the potential use of caspofungin eye drops as a novel strategy to treat fungal keratitis, with the intention of improving clinical outcomes and saving costs. The successful use of intrastromal and topical caspofungin 0.5% in combination with voriconazole in a case of refractory atypical Alternaria keratitis in a local institution was reported. The utility of caspofungin eye drops in fungal keratitis, however, remains limited, partly due to the lack of data on penetration into the human eye. A liquid chromatography/mass spectrometry assay was then developed and validated to determine the concentrations of caspofungin in human aqueous humour. An open-label study demonstrated that caspofungin 0.5% eye drops resulted in low penetration into the human eye in the absence of inflammation or corneal abrasion, but were generally well tolerated. The eye drops were shown to be stable for at least 28 days at 4 ± 1oC, affording economical use in clinical practice. This thesis has explored a number of important aspects related to the optimal and cost-efficient use of high-cost antifungal agents. Significantly, the data will facilitate informed decision making by clinical practitioners and healthcare policy makers about the use of these high-cost antifungal agents.

Dissolving microneedle patches loaded with amphotericin B microparticles for localised and sustained intradermal delivery: Potential for enhanced treatment of cutaneous fungal infections

Background: Fusarium is a mold mainly known as plant and animal pathogen. Recently, there has been an increasing number of reports about fusarium infection in humans, especially as opportunistic infection in immunocompromised patients with a significant morbitiy and mortality rate. The aim of this study is to further elucidate the behavior of fusariosis in humans. Methods: We analyzed all reports of Fusarium infection in the English and German literature from 1958 to 2007. Data about the age, gender, underlying condition, symptoms, Fusarium species, treatment and outcome were analyzed. Results: 213 cases with either histologically or culture proven infection were included. 62.5% (n=133) were male. The median age of the patients was 39.9 years (range: 0.04-82 years). The overall mortality rate was 34.7% (n=74), with a direct correlation between the underlying condition, the immune status of the patient and the site of infection. No underlying condition was found in only 4.2% (n=9) of all cases. All of them survived and none of them had a disseminated disease. A disseminated infection was detected in 40% (n=86) of all analyzed cases with fusariosis. The second leading site of Fusarium infection was the skin 22.5% (n=48) and eye 15% (n=33). Fusarium solani was the most frequent species. 92.5% (n=197) of all patients received antifungal therapy. The most frequent used antifungal agent was amphotericin B deoxycholate and its liposomal equivalent. Only 6 patients received no treatment at all, neither surgery nor any sort of medication. 4 of them died. Conclusion: From the first case in 1958 an increasing number of cases were published each decade with a peak between 1990-1999. The outcome depends on the site of infection and the immune status of the patient. Disseminated Fusariosis in immunocompromised patients had a very poor outcome. Usually a recovery is achieved as soon as the immune status of the patient improves.

New antifungal agents