MIC and fungicidal activity of terbinafine against clinical isolates of Aspergillus spp

TERBINAFINE PHARMACOKINETICS FOLLOWING SINGLE-DOSE ORAL ADMINISTRATION IN RED-EARED SLIDER TURTLES (TRACHEMYS SCRIPTA ELEGANS): A PILOT STUDY

In this pilot study, the pharmacokinetics of terbinafine were determined in six apparently healthy red-eared slider turtles (Trachemys scripta elegans) after a single PO administration. Terbinafine suspension (15 mg/kg, once) was administered via gavage tube to all turtles. Blood samples were collected immediately before (time 0) and at 1, 2, 4, 8, 24, and 48 h after drug administration. Plasma terbinafine concentrations were quantified by ultra-performance liquid chromatography-mass spectrometry, and noncompartmental pharmacokinetic analysis was performed. None of the animals showed any adverse responses following terbinafine administration. Mean area under the curve from time 0 to 24 h was 1,213 h × ng/ml (range 319-7,309), mean peak plasma concentration was 201.5 ng/ml (range 45.8-585.3), mean time to maximum plasma concentration was 1.26 h (range 1-4), mean residence time was 7.71 h (range 3.85-14.8), and mean terminal half-life was 5.35 h (range 2.67-9.83). The administration of terbinafine (15 mg/kg, PO) may be appropriate for treatment of select fungal organisms with low minimum inhibitory concentrations in red-eared slider turtles but may require q12h administration even for organisms with low minimum inhibitory concentrations. Multiple-dose studies as well as clinical studies are needed to determine ideal dosages and efficacy.

THE ISOLATION AND ANTIMICROBIAL SENSITIVITY OF ASPERGILLUS FUMIGATUS FROM FROZEN RESPIRATORY TISSUES OF PENGUINS FROM ZOOLOGICAL COLLECTIONS IN THE UNITED KINGDOM, 2007-2018

Fifty-eight frozen postmortem lung and air sac samples were collected from penguins housed at 21 zoological collections throughout the United Kingdom, from 2007 to 2018. Aspergillus fumigatus, a significant respiratory pathogen of penguins in captivity, was isolated from 15 of the 22 penguins with gross lesions. Of the penguins with gross lesions of aspergillosis at postmortem examination, the pathogen was cultured from 63.6% (15 of 22) of frozen samples. Aspergillus fumigatus was cultured from 2.7% (1 of 36) of tissues collected from penguins without gross lesions at postmortem. Additionally, of 18 fresh samples that cultured A. fumigatus at the time of postmortem, 15 samples (83%) yielded isolates that were successfully cultured from frozen tissue. Minimum inhibitory concentration (MIC) data demonstrated that all isolates were susceptible to terbinafine and voriconazole, and all were resistant to itraconazole, using published MIC cutoff values. Comparison isolates from fresh tissues had identical antimicrobial susceptibility to isolates from the same tissues after being frozen. This study demonstrates that A. fumigatus can be isolated from frozen respiratory tissues of penguins, even after freezing for more than 10 yr.

Identification and in vitro antifungal susceptibility of causative agents of onychomycosis due to Aspergillus species in Mashhad, Iran

Aspergillus species are emerging causative agents of non-dermatophyte mold onychomycosis. In this study, 48 Aspergillus isolates were obtained from patients with onychomycosis in Mashhad, Iran, during 2015–2018. The aim is to identify the Aspergillus isolates to the species level by using partial calmodulin and beta-tubulin gene sequencing and MALDI-TOF MS, and to evaluate their in vitro susceptibility to ten antifungal drugs: terbinafine, itraconazole, voriconazole, posaconazole, ravuconazole, isavuconazole, caspofungin, micafungin, anidulafungin and amphotericin B according to CLSI M38-A3. Our results indicate that A.flavus (n = 38, 79%) is the most common Aspergillus species causing onychomycosis in Mashhad, Iran. Other detected species were A. terreus (n = 3), A. tubingensis (n = 2), A. niger (n = 1), A. welwitschiae (n = 1), A. minisclerotigenes (n = 1), A. citrinoterreus (n = 1) and A. ochraceus (n = 1). Aspergillus flavus, A. terreus and A. niger isolates were correctly identified at the species level by MALDI-TOF MS, while all cryptic species were misidentified. In conclusion, A. flavus is the predominant Aspergillus species causing onychomycosis due to Aspergillus spp. in Mashhad, Iran. MALDI-TOF MS holds promise as a fast and accurate identification tool, particularly for common Aspergillus species. It is important that the current database of reference spectra, representing different Aspergillus species is expanded to increase the precision of the species-level identification. Terbinafine, posaconazole and echinocandins were in vitro most active against the studies Aspergillus isolates and terbinafine could be the first choice for treatment of onychomycosis due to Aspergillus.

Molecular Identification and Antifungal Susceptibility of Yeasts and Molds Isolated from Patients with Otomycosis

Fungal otitis externa, an infection of the external auditory canal caused by molds and yeasts, accounts for approximately 10-20% of ear canal infections accompanying high recurrence. The purpose of the current study was to assess the pattern of etiological agents of otomycosis and resistance profile as well as the rate of tympanic membrane perforation. A total of 1040 patients with symptoms of fungal otitis externa, in a period of two years, were investigated. The mycological tests revealed the presence of different fungi in 237 ears (22.8%). Fungal otitis was more related to filamentous fungi of the species Aspergillus flavus (54.43%), A. tubingensis (10.97%), and A. niger (8.86%), followed by yeasts, Candida orthopsilosis (7.59%), C. albicans (6.75%), and C. parapsilosis (5.06%). Tympanic membrane perforation rate was found to be 6.75% and was more common with otomycosis caused by A. flavus, A. tubingensis and C. albicans. In antifungal susceptibility tests, all tested drugs showed generally good activity against most isolates of molds and yeasts, while tolnaftate, clotrimazole, nystatin, and terbinafine had lowest effects. We found that among Aspergillus isolates, one A. niger isolate was resistant to voriconazole, and one A. flavus isolate was resistant to amphotericin B. Furthermore, among Candida species, three isolates of C. orthopsilosis showed high MIC values to fluconazole, two C. albicans isolates were considered fluconazole resistant and one isolate of C. parapsilosis was resistant to caspofungin and 3 isolates were resistant to fluconazole. Regarding the existence of the cases with perforated tympanic membrane and emerging species causing fungal otitis in the current report, the importance of the early physical examination, precise molecular identification, and the antifungal susceptibility evaluation is highlighted.

Pharmacokinetics of single dose oral Terbinafine in common shelducks (Tadorna tadorna)

Fungal disease is a major cause of morbidity and mortality in avian species; thus, antifungals are the treatment of choice. Despite widely used in clinical practice, terbinafine pharmacokinetic studies are scarce in literature and only cover some avian families, with marked differences between them. This study evaluates the pharmacokinetic behaviour of terbinafine after a single oral administration of 60 mg/kg in 7 healthy adult common shelducks (Tadorna tadorna) by measuring plasma concentrations through high-performance liquid chromatography (HPLC) at times 0, 30 min, 1, 2, 4, 6, 8, 10, 12, 24, 36 and 48 hr postadministration. Noncompartmental analyses of the data showed a C_max (geometric mean) of 5.43 µg/ml, t_max (median) 1.0 hr and AUC_0-∞ 29.70 mg h/L. Elimination half-life was 6.33 hr and MRT 6.61 hr. Plasma concentrations remained above previously described MIC for terbinafine in some fungal species for at least 6 to 8 hr. A single oral administration of 60 mg/kg terbinafine did not produce adverse effects and could be a good treatment choice for fungal diseases in anatids.

Eradicating Otomycosis with Terbinafine Solution: Basic and Clinical Investigation

BACKGROUND

Otomycosis still remains intractable in clinical practice, likely because topical antifungal agents lack efficacy or are potentially toxic to the inner ear end organs.

OBJECTIVES

The aim of this study was to investigate whether terbinafine solution is a potential candidate for treating intractable otomycosis in humans. In addition, the toxic effect on the inner ear was also assessed by animal models treated with terbinafine.

METHODS

Guinea pigs were instilled with 0.1 mL terbinafine (10 and 25 mg/mL) in the left round window membrane. At 2 weeks after treatment, all animals underwent an inner ear test battery and were then sacrificed for morphological study. Clinically, 20 patients with otomycosis were treated with terbinafine solution at a dosage of 0.4 mg.

RESULTS

All terbinafine-treated animals showed intact inner ear function when total dosage of terbinafine was <2.5 mg, which was further confirmed by morphological study. Subsidence of otomycosis was achieved in all 20 patients 1 week after treatment with terbinafine (0.4 mg) without untoward effect. No evidence of recurrence was noted 1 year after treatment.

CONCLUSION

The paucity of inner ear toxicity of terbinafine even at a dosage of 2.5 mg was identified in guinea pig models morphologically and physiologically. Topical application of terbinafine solution at a dosage of 0.4 mg may be a potential treatment for otomycosis in humans.

Exploration of Islamic medicine plant extracts as powerful antifungals for the prevention of mycotoxigenic Aspergilli growth in organic silage

BACKGROUND

Feed contamination with mycotoxins is a major risk factor for animals and humans as several toxins can exist as residues in meat and milk products, giving rise to carry-over to consumers via ingestion of foods of animal origin. The starting point for prevention, in this chain, is to eliminate the growth of mycotoxigenic fungi in the animal forage. Ten plant extracts, recommended in Islamic medicine, were evaluated as antifungal agents against mycotoxigenic Aspergilli, i.e. Aspergillus flavus and A. ochraceus, growth in organic maize silage.

RESULTS

Most extracts had remarkable antifungal activities using both qualitative and quantitative evaluation methods. Cress (Lepidium sativum) seed extract was proven to be the most powerful among the plants examined. Blending of the most effective extracts (garden cress seed, pomegranate peel and olive leaf extracts), individually at their minimal fungicidal concentrations, with maize silage resulted in the reduction of inoculated A. flavus colony counts by 99.9, 99.6 and 98.7%, respectively, whereas silage blending with the combined extracts completely prohibited fungal growth for up to 30 days of incubation under aerobic conditions.

CONCLUSION

Besides the health promoting effects, silage blending with the bioactive plant extracts examined could lead to the required protection from pathogenic and mycotoxigenic fungi.

Pharmacokinetics of orally administered terbinafine in African penguins (Spheniscus demersus) for potential treatment of aspergillosis

The objective of this study was to determine the pharmacokinetic parameters of orally administered terbinafine hydrochloride based on 3, 7, and 15 mg/kg single- as well as multiple-dosage trials in order to calculate dosing requirements for potential treatment of aspergillosis in African penguins (Spheniscus demersus). Ten adult African penguins were used in each of these trials, with a 2-wk washout period between trials. Mean plasma concentrations of terbinafine peaked in approximately 4 hrs at 0.11 +/- 0.017 microg/ml (mean +/- SD) following administration of 3 mg/kg terbinafine, while 7 mg/kg and 15 mg/kg dosages resulted in peak plasma concentrations of 0.37 +/- 0.105 and 0.33 +/- 0.054 microg/ml, respectively. The volume of distribution increased with increasing dosages, being 37 +/- 28.5, 40 +/- 28.1, and 52 +/- 18.6 mg/L for 3, 7, and 15 mg/kg doses, respectively. The mean half-life was biphasic with initial terminal half-life (t(1/2)) values of 9.9 +/- 4.5, 17.2 +/- 4.9 and 16.9 +/- 5.4 hrs, for 3, 7, and 15 mg/kg doses, respectively. A rapid first elimination phase was followed by a slower second phase, and final elimination was estimated to be 136 +/- 9.7 and 131 +/- 9.9 hrs, for 7 and 15 mg/kg doses, respectively. Linearity was demonstrated for area under the curve but not for peak plasma concentrations for the three dosages used. Calculations based on pharmacokinetic parameter values indicate that a 15 mg/kg terbinafine q24h dosage regimen would result in steady-state trough plasma concentrations above the minimum inhibitory concentration (0.8-1.6 microg/ ml), and this dosage is recommended as a potential treatment option for aspergillosis in penguins. However, additional research is required to determine both treatment efficacy and safety.

Update on terbinafine with a focus on dermatophytoses

Since terbinafine was introduced on the world market 17 years ago, it has become the leading antifungal for the treatment of superficial fungal infections, aided by unique pharmacologic and microbiologic profiles. This article reviews mode of action, antimycotic spectrum and disposition profile of terbinafine. It examines the data, accumulated over 15 years, on the comparative efficacy of terbinafine (vs griseofulvin, itraconazole, fluconazole) in the management of the infections for which it is primarily indicated (eg, dermatophytoses) and provides a brief discussion on its use for the treatment of non-dermatophyte infections. Finally, the available data on the newest topical and systemic formulations are introduced.

Fungal cell wall septation and cytokinesis are inhibited by bleomycins

When the essential and distinctive cell walls of either pathogenic or nonpathogenic fungi break, cytoplasmic membranes rupture and fungi die. This fungicidal activity was discovered previously on nonproliferating Saccharomyces cerevisiae cells treated briefly with the oxidative tool and anticancer drug family of bleomycins. The present studies investigated effects of bleomycin on growing fungal organisms. These included the medically important Aspergillus fumigatus and Cryptococcus neoformans, as well as the emerging human pathogen and fungal model, S. cerevisiae. Bleomycin had its highest potency against A. fumigatus. Scanning electron microscopy and thin-section transmission electron microscopy were used to study morphological growth characteristics. Killing and growth inhibition were also measured. Long, thin, and segmented hyphae were observed when A. fumigatus was grown without bleomycin but were never observed when the mold was grown with the drug. Bleomycin arrested conidial germination, hyphal development, and the progression and completion of cell wall septation. Similarly, the drug inhibited the construction of yeast cell wall septa, preventing cytokinesis and progression in the cell division cycle of S. cerevisiae. Even when cytoplasms of mother and daughter cells separated, septation and cell division did not necessarily occur. Bizarre cell configurations, abnormally thickened cell walls at mother-daughter necks, abnormal polarized growth, large undivided cells, fragmented cells, and empty cell ghosts were also produced. This is the first report of a fungicidal agent that arrests fungal growth and development, septum formation, and cytokinesis and that also preferentially localizes to cell walls and alters isolated cell walls as well as intact cell walls on nongrowing cells.

In vitro activities of terbinafine against Aspergillus species in comparison with those of itraconazole and amphotericin B

Compared with the in vitro activities of itraconazole (geometric mean MIC [GM], 0.56 microg/ml) and amphotericin B (GM, 0.66 microg/ml), the in vitro activity of terbinafine was inferior against Aspergillus fumigatus (GM, 19.03 microg/ml) (P < 0.05) and superior against A. flavus (GM, 0.10 microg/ml), A. terreus (GM, 0.16 microg/ml), and A. niger (GM, 0.19 microg/ml). Clinical correlation is required, as trailing endpoints are problematic.

Synergistic interaction of terbinafine with triazoles or amphotericin B against Aspergillus species

The in vitro activity of terbinafine alone and in combination with other antifungal agents was tested against isolates of Aspergillus fumigatus, A. flavus and A. niger. Testing was performed in a modified National Committee for Clinical Laboratory Standards (NCCLS) macrodilution broth assay, and interactions were examined using a checkerboard design. Terbinafine was highly active against Aspergillus isolates (minimum inhibitory concentration [MIC] 0.01 to 2 microg ml(-1)) with a primary fungicidal action (minimum fungicidal concentration [MFC] 0.02 to 4 microg ml(-1)). Amphotericin B was also highly active and cidal as expected (MIC 1 microg ml(-1), MFC 1 to 4 microg ml(-1)). The triazoles itraconazole and voriconazole were highly active but showed a variable degree of cidal activity against the different strains, voriconazole having the more potent cidal activity. Fluconazole had no significant activity (MIC > 128 microg ml(-1)). Drug combinations were tested in the A. fumigatus and A. niger strains. Terbinafine and amphotericin showed an additive to synergistic interaction depending on the isolate. Combinations of terbinafine with itraconazole or voriconazole displayed a potent synergistic interaction and fungicidal activity against all isolates. Surprisingly, fluconazole also potentiated the activity of terbinafine in an additive to synergistic fashion, despite its lack of activity alone. The results suggest potential clinical application of terbinafine in aspergillosis, either alone or in combination with amphotericin or triazoles.

Inhibitory effect of seven Allium plants upon three Aspergillus species

Antifungal activity and minimal fungicidal concentration (MFC) of extracts of garlic, bakeri garlic, Chinese leek, Chinese chive, scallion, onion bulb and shallot bulb against Aspergillus niger, A. flavus and A. fumigatus were examined. These Allium plants possessed antifungal activity, with garlic showing the lowest MFC. With the exception of scallion, the inhibitory effect of Allium plants against three Aspergillus species decreased with increasing incubation and heating temperature (P < 0.05). Acetic acid treatments of the extracts increased the inhibitory effect for all plants against three fungi (P < 0.05), and there was no significant difference in this effect among the three pH (2, 4, 6) treatments (P > 0.05) investigated. Acetic acid, at pH = 4, plus heat treatments of the extracts resulted in a greater inhibitory effect for all Allium plants against the three fungi than heat treatment alone (P < 0.05). Treatments of the extracts with NaCl, at concentrations of 0.2 and 0.4 M, did not affect the inhibitory effect of the plant extracts. The combination of acetic acid plus Allium plants was indicated to be an effective way to inhibit fungal growth.

Invasive aspergillosis caused by Aspergillus ustus: case report and review

A case of invasive pulmonary aspergillosis in an allogeneic bone marrow transplant recipient caused by Aspergillus ustus is presented. A. ustus was also recovered from the hospital environment, which may indicate that the infection was nosocomially acquired. A literature review revealed seven cases of invasive infections caused by A. ustus, and three of these were primarily cutaneous infections. In vitro susceptibility testing of 12 A. ustus isolates showed that amphotericin B and terbinafine had fungicidal activity and that itraconazole and voriconazole had fungistatic activity.

Antifungal agents in the 1990s. Current status and future developments

Significant advances in antifungal therapy have occurred in the last decade. Most of these advances have been tied to the introduction of the triazoles, itraconazole and fluconazole. Itraconazole has proved efficacious for the treatment of subacute to chronic infections with the endemic mycoses and other opportunistic filamentous fungi, including Aspergillus spp. Fluconazole is now routinely used for mucocutaneous and systemic candidiasis, and its use for coccidioidal meningitis has obviated the need for intrathecal amphotericin B in most patients. Large, well controlled trials in AIDS patients with cryptococcal meningitis have shown the benefit of induction therapy with amphotericin B and flucytosine, followed by consolidation and life-long maintenance therapy with fluconazole. Concomitant with the increased use of these well tolerated, effective oral triazole agents has come the emergence of drug resistance in AIDS patients and shifts in the species of yeasts causing infection in hospitalised patients. Amphotericin B remains the drug of choice for many fungal infections, especially those that are life-threatening. Lipid-containing formulations of amphotericin B have recently been approved: these preparations significantly reduce the risk of amphotericin B-induced nephrotoxicity. Several new fungicidal agents are currently in early trials. With the increasing number of available antifungal drugs, future studies will help define the appropriate niche for each and the possible benefit of therapy with combinations of drugs.

Characterization of amphotericin B aerosols for inhalation treatment of pulmonary aspergillosis

In recent years, the incidence of invasive pulmonary aspergillosis has increased in patients receiving immunosuppressive therapy and/or organ transplantation. For prophylaxis against Aspergillus infections, amphotericin B may be a useful drug when inhaled as aerosol. In this study, the aerosolization of amphotericin B was investigated using eight different medical nebulizers under various operating conditions and with different amphotericin B concentrations in the solution. The output of each nebulizer was characterized by the mass flow of spray (drug) leaving the mouthpiece and by the size distribution of the droplets. An effective prevention of pulmonary aspergillosis via amphotericin B inhalation requires a high pulmonary deposition of the drug within an acceptable time of administration associated with a low deposition in the oropharyngeal region. To evaluate the dosages of drug delivered by various types of nebulizers to different regions of the respiratory tract, a semi-empirical deposition model was applied which is based on experimental aerosol deposition data from over 20 normal adults. The main results of the study are: Solutions with amphotericin B concentrations up to 10 mg/ml can be converted into sprays by means of medical nebulizers without any problems. For most nebulizers, the slight foaming of the amphotericin B solution has no effect on the production of the aerosol. To optimize amphotericin B treatment of the lungs via inhalation, sprays with mass flows above 100 mg/min and with mass median aerodynamic diameters (MMAD) below 3 microns should be slowly inhaled by the subject. Applying these criteria to the nebulizers investigated, three out of eight devices have proved suitable for amphotericin B treatment via inhalation.

Refractory pulmonary aspergillosis: compassionate trial with terbinafine

The frequency of bronchopulmonary aspergillosis is increasing due to the growing number of patients requiring steroids or other immunosuppressive therapies. Conventional treatments are ineffective in some patients and side-effects are an important issue. The aim of this work was to evaluate the effectiveness and safety of terbinafine, a new allylamine antimycotic drug, in three immunocompetent patients affected by lower respiratory tract aspergillosis [one chronic empyema due to Aspergillus fumigatus (AF) and two chronic necrotising aspergillosis] not responsive to the usual antimycotic therapies. In in vitro and animal model systems, terbinafine is as active as amphotericin B and itraconazole. Patients received terbinafine at doses ranging from 5 to 15 mg/kg per day, according to clinical status, for 3-5 months, depending on the clinical course of the disease and compliance. In patient 1 a negative anti-AF precipitin was obtained together with eradication of AF from the pleural cavity, which allowed a successful intrathoracic myo-omento-mammoplasty. In patients 2 and 3, AF was eradicated, anti-AF immunoprecipitins decreased, and clinical and radiological findings significantly improved. On the basis of the effectiveness of terbinafine demonstrated in this preliminary work, large studies to evaluate the use of terbinafine in bronchopulmonary aspergillosis are warranted. Moreover, the drug is not associated with resistance or significant side-effects.

Terbinafine in the treatment of non-immunocompromised compassionate cases of bronchopulmonary aspergillosis

Conventional treatments of broncho-pulmonary aspergillosis are often ineffective and result in associated side-effects. Terbinafine (a new allylamine derivative), although as active against Aspergillus in vitro as amphotericin B and itraconazole, is less effective in rodent models because of a rapid hepatic first-pass effect. As terbinafine is metabolized differently in humans, the aim of this work was to evaluate this drug, for the first time, in the treatment of seven immunocompetent patients with lower respiratory tract mycotic infections unresponsive to the usual antimycotic drugs. Diagnosis was based on identification of fungal isolates, worsening of respiratory function tests, chest radiographs and computerized tomographic (CT) scan changes, positive skin test, aspergillin precipitins and clinical history. Terbinafine was administered at doses ranging from 5 to 15 mg kg-1 day-1 depending on the clinical severity of the disease, and was given for 90-270 days depending on clinical progress and compliance. In three patients A. fumigatus was suppressed with resolution of signs and symptoms; four patients showed transitory A. fumigatus suppression with marked clinical and radiological improvement. During relapses no resistance to terbinafine was observed. No significant side-effects were detected. Terbinafine appeared to be as effective as amphotericin B and itraconazole in the treatment of bronchopulmonary aspergillosis in nonimmunocompromised patients. These preliminary results suggest that controlled studies are warranted.

Nosocomial outbreak caused by Scedosporium prolificans (inflatum): four fatal cases in leukemic patients

Four cases of fatal disseminated Scedosporium prolificans (inflatum) infection occurring in neutropenic patients are reported. Because of hospital renovation, the patients were cared for in a temporary hematologic facility. S. prolificans (inflatum) was isolated from blood cultures of these four patients, two of whom underwent full necropsy, and revealed abundant vegetative hyphae and ovoid conida with truncate bases in many organs. In vitro susceptibility testing of fungal strains showed all isolates to be resistant to amphotericin B, flucytosine, miconazole, ketoconazole, fluconazole, and itraconazole, with MICs greater than 16 micrograms/ml. The reported infections, two in each of two rooms, occurred over a period of 1 month, with very similar clinical outcomes. Circumstancial evidence suggested a nosocomial outbreak, but the environmental samples collected from the rooms, corridors, and adjacent areas did not yield S. prolificans (inflatum). Nevertheless, circumstantial evidence suggested a nosocomial outbreak of S. prolificans (inflatum) infection.

Comparative efficacy of amphotericin B, clotrimazole and itraconazole against Aspergillus spp. An in vitro study

The susceptibilities of two isolates of Aspergillus flavus, one from a human case of recalcitrant mycotic keratitis, and an environmental isolate of A. fumigatus, to itraconazole, clotrimazole and amphotericin B were measured. Observations of macroscopic growth and microscopic evaluations of conidia germination both indicated that the two isolates of A. flavus were markedly more resistant to amphotericin B than to itraconazole and clotrimazole. Itraconazole was more effective than clotrimazole for all isolates. Our in vitro susceptibility results suggest the use of itraconazole should be a primary consideration in the treatment of Aspergillus keratitis.

Rapid and highly reproducible method for antifungal susceptibility testing of Aspergillus species

A new method for determining the MICs for Aspergillus species with slant-shaking incubation is described. The method was rapid (24 h), produced sharp visual end points, and showed high reproducibility. Additionally, MICs measured by this method correlated well with, as well as were two- to sixfold lower than, those by a reference method.

Application of ubiquinone systems and electrophoretic comparison of enzymes to identification of clinical isolates of Aspergillus fumigatus and several other species of Aspergillus

The ubiquinone systems and electrophoretic comparison of enzymes were used to determine the relatedness among 64 isolates of seven Aspergillus spp. These were 31 clinical and 3 nonclinical isolates of Aspergillus fumigatus Fres., 2 isolates of A. nidulellus Samson & W. Gams, 8 isolates of A. terreus Thom, 4 isolates of A. flavus Link, 1 isolate of A. oryzae (Ahlburg) Cohn, 14 isolates of A. niger van Tieghem, and 1 isolate of A. japonicus Saito. The enzymes glucose 6-phosphate dehydrogenase, lactate dehydrogenase, glutamate dehydrogenase, fumarase, and malate dehydrogenase were examined. The relative mobilities were analyzed numerically. The results were presented as a dendrogram. Isolates from clinical and nonclinical sources within the same species had identical ubiquinone systems and identical or very similar enzyme patterns. In the dendrogram, 64 of the tested isolates were separated into seven major clusters at a 60% similarity level. Each major cluster corresponds to a single species. On the dendrogram, A. fumigatus isolates showed homogeneity, whereas A. niger isolates showed relative heterogeneity; in particular, A. niger MF-24 and the other A. niger isolates were distantly linked to each other. All A. fumigatus isolates had the Q-10 ubiquinone system and formed a single major cluster at a similarity level of 73% or greater. Glucose 6-phosphate dehydrogenase and glutamate dehydrogenase were key enzymes for differentiating all clinical and nonclinical isolates of A. fumigatus from the other Aspergillus spp. Ubiquinone systems and enzyme patterns appear to be objective and useful indicators for use in the precise identification of clinical isolates of Aspergillus spp.

Terbinafine. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in superficial mycoses

Terbinafine is an orally and topically active allylamine antifungal agent with a primarily fungicidal action in vitro. Its spectrum of in vitro activity includes a broad range of dermatophyte, filamentous, dimorphic and dematiaceous fungi, and some yeast species. In clinical trials, mycological and overall efficacy rates of around 90 and 80%, respectively, have been achieved in cutaneous dermatophyte infections (tinea corporis/cruris and tinea pedis) with terbinafine, administered either orally (250 or 500 mg/day) or topically (a 1% cream applied twice daily). Similar rates of cure have been obtained with oral terbinafine in dermatophyte nail infections after relatively short treatment periods ranging from 3 to 12 months. Topical terbinafine has been effective in approximately 80% of patients with cutaneous candidiasis or pityriasis versicolor. Few comparative data have been published, but generally oral terbinafine appeared to be at least as effective as oral griseofulvin or ketoconazole in tinea corporis/cruris and more effective than griseofulvin in tinea pedis. Both oral and topical terbinafine have been very well tolerated in clinical trials to date, with only minor adverse effects reported. Although further research is required to establish the efficacy of terbinafine in comparison with other available therapies, as well as to fully clarify its tolerability profile, the early results obtained with terbinafine in superficial fungal infections are very encouraging. Terbinafine appears likely to become a first-line therapy for dermatophyte infections, particularly those affecting the nails.

Inactivity of terbinafine in a rat model of pulmonary aspergillosis

In a model of bronchopulmonary aspergillosis terbinafine did not improve survival of experimental animals in doses up to 80 mg/kg/day despite adequate lung concentrations. Pretreatment and aerosolization of the compound were also ineffective. Terbinafine was markedly less active in vitro when serum was used instead of Yeast-Nitrogen-Glucose-broth. It is concluded that a lack of bioavailability in the presence of serum may explain the lack of activity of terbinafine in experimental aspergillosis.

A clinical trial of topical terbinafine (a new allylamine antifungal) in the treatment of tinea pedis

Twenty-three patients were enrolled in a randomized, double-blind trial of terbinafine 1% cream compared with placebo vehicle in the treatment of tinea pedis. Of the 20 patients who were evaluated for efficacy, 10 received terbinafine and 10 received placebo. Except for the terbinafine-treated patients being an average of 11 years older than the patients receiving placebo and the median duration of disease being 6 weeks longer in the placebo group, the two groups were demographically and clinically similar. Results of mycologic tests and clinical findings showed terbinafine to be significantly more effective than placebo in the treatment of tinea pedis. Significantly more terbinafine-treated patients than placebo-treated patients showed conversion to negative culture and microscopy at end of therapy and a significant reduction in scored signs and symptoms. Overall efficacy at follow-up (combined mycologic and clinical findings) was also significantly greater in the terbinafine group (78%) than in the placebo group (zero) (p less than 0.001). Unexplained elevation of liver function test results was noted in three placebo-treated patients and in one terbinafine-treated patient, but these changes were not considered clinically relevant or drug related.

Aerosol amphotericin B is effective for prophylaxis and therapy in a rat model of pulmonary aspergillosis

Invasive pulmonary aspergillosis is a major life-threatening complication among transplant recipients and patients receiving cancer chemotherapy. In a rat model of progressive pulmonary aspergillosis that is characterized by hyphal bronchopneumonia, aerosol amphotericin B (aero-AmB; 1.6 mg/kg given 2 days before infection) significantly delayed mortality in rats compared with animals in a control group. The first death in the aero-AmB-treated group occurred on day 11, by which time seven of the eight control animals had died. The same dose of aero-AmB given as treatment (1.6 mg/kg given 24 h after infection and then daily for 6 days) was also effective. In this trial, eight of the ten animals treated with aero-AmB survived for 7 days, whereas only one of ten control animals survived. Colony counts in lung homogenates obtained 24 h after infection showed an 80-fold reduction in the number of viable spores in animals that had received 6.4-mg/kg doses of aero-AmB 2 days prior to infection. At 48 h after administering a single 1.6- or 3.2-mg/kg dose of aero-AmB, mean lung concentrations were 2.79 and 5.22 micrograms/g of tissue, respectively. We conclude, therefore, that aero-AmB kills inhaled spores and delays the progression of pulmonary aspergillosis by inhibiting mycelial proliferation.