Antifungal susceptibility profile of Aspergillus fumigatus isolates from avian lungs / Perfil de suscetibilidade antifúngica de isolados de Aspergillus fumigatus provenientes de pulmões de aves

Susceptibility testing is essential to inform the correct management of Aspergillus infections. In this study we present antifungal susceptibility profile of A. fumigatus isolates recovered from lungs of birds with and without aspergillosis. Fifty three isolates were tested for their antifungal susceptibility to voriconazole (VRC), itraconazole (ITZ), amphotericin (AMB) and caspofungin (CSP) using the M38-A2 broth microdilution reference method. Five isolates were resistant to more than one antifungal drug (CSP + AMB, VRC + ITZ and AMB + ITZ). Fifteen (28%) isolates with susceptible increased exposure (I) to ITZ were sensible to VRC. Resistance to AMB (>2µg/mL) was observed in only four isolates. Eleven (21%) A. fumigatus present resistance to ITZ (13%) and VRC (8%). Fungal isolation from respiratory samples has been regarded as being of limited usefulness in the ante mortem diagnosis of aspergillosis in birds. However, the results suggest that the detection and antifungal susceptibility profile may be helpful for monitoring of therapy for avian species and where antifungal resistance might be emerging and what conditions are associated to the event.(AU)

Os testes de suscetibilidade são essenciais para informar o correto manejo das infecções por Aspergillus. Neste estudo apresentamos o perfil antifúngico de isolados de A. fumigatus provenientes de pulmões de aves com e sem aspergilose. Cinqüenta e três isolados foram testados quanto à susceptibilidade antifúngica ao voriconazol (VRC), itraconazol (ITZ), anfotericina B (AMB) e caspofungina (CSP) pelo método de referência de microdiluição do caldo M38-A2. Cinco isolados foram resistentes a mais de um antifúngico (CSP + AMB, VRC + ITZ e AMB + ITZ). Quinze (28%) isolados suscetíveis - com exposição aumentada (I) ao ITZ foram sensíveis ao VRC. A resistência ao AMB (>2µg/mL) foi observada em apenas quatro isolados. Onze (21%) A. fumigatus apresentaram resistência a ITZ (13%) e VRC (8%). O isolamento de fungos de amostras respiratórias tem sido considerado de utilidade limitada no diagnóstico ante mortem de aspergilose em aves. No entanto, os resultados sugerem que a detecção e o perfil de suscetibilidade a antifúngicos podem ser úteis para o monitoramento da terapia de espécies aviárias, assim como a emergência da resistência antifúngica e quais condições podem estar associadas ao evento.(AU)

In vitro antifungal susceptibility of clinical and environmental isolates of Aspergillus fumigatus and Aspergillus flavus in Brazil

ABSTRACT The in vitro susceptibility of 105 clinical and environmental strains of Aspergillus fumigatus and Aspergillus flavus to antifungal drugs, such as amphotericin B, azoles, and echinocandins was evaluated by the broth microdilution method proposed by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Following the EUCAST-proposed breakpoints, 20% and 25% of the clinical and environmental isolates of A. fumigatus, respectively, were found to be resistant to itraconazole (Minimal Inhibitory Concentration, MIC > 2.0 mg/L). Voriconazole showed good activity against A. fumigatus and A. flavus strains, except for one clinical strain of A. fumigatus whose MIC was 4.0 mg/L. Posaconazole (≤0.25 mg/L) also showed appreciable activity against both species of Aspergillus, except for six A. fumigatus strains with relatively higher MICs (0.5 mg/L). The MICs for Amphotericin B ranged from 0.06 to 1.0 mg/L for A. fumigatus, but were much higher (0.5-8.0 mg/L) for A. flavus. Among the echinocandins, caspofungin showed a geometric mean of 0.078 and 0.113 against the clinical and environmental strains of A. flavus, respectively, but had elevated minimal effective concentrations (MECs) for seven of the A. fumigatus strains. Anidulafungin and micafungin exhibited considerable activity against both A. fumigatus and A. flavus isolates, except for one environmental isolate of A. fumigatus that showed an MEC of 1 mg/L to micafungin. Our study proposes that a detailed investigation of the antifungal susceptibility of the genus Aspergillus from different regions of Brazil is necessary for establishing a response profile against the different classes of antifungal agents used in the treatment of aspergillosis.

Carum copticum and Thymus vulgaris oils inhibit virulence in Trichophyton rubrum and Aspergillus spp

Emergence of drug-resistant strains has demanded for alternative means of combating fungal infections. Oils of Carum copticum and Thymus vulgaris have long been used in ethnomedicine for ailments of various fungal infections. Since their activity has not been reported in particular against drug-resistant fungi, this study was aimed to evaluate the effects of oils of C. copticum and T. vulgaris on the growth and virulence of drug-resistant strains of Aspergillus spp. and Trichophyton rubrum. The gas chromatography-mass spectrometry analysis revealed thymol constituting 44.71% and 22.82% of T. vulgaris and C. copticum, respectively. Inhibition of mycelial growth by essential oils was recorded in the order of thymol > T. vulgaris > C. copticum against the tested strains. RBC lysis assay showed no tested oils to be toxic even up to concentration two folds higher than their respective MFCs. Thymol exhibited highest synergy in combination with fluconazole against Aspergillus fumigatus MTCC2550 (FICI value 0.187) and T. rubrum IOA9 (0.156) as determined by checkerboard method. Thymol and T. vulgaris essential oil were equally effective against both the macro and arthroconidia growth (MIC 72 µg/mL). A > 80% reduction in elastase activity was recorded for A. fumigatus MTCC2550 by C. copticum, T. vulgaris oils and thymol. The effectiveness of these oils against arthroconidia and synergistic interaction of thymol and T. vulgaris with fluconazole can be exploited to potentiate the antifungal effects of fluconazole against drug-resistant strains of T. rubrum and Aspergillus spp.

Drug susceptibility of aAspergillus flavus and A.fumigatus to itraconazole and amphotericin B

Aspergillosis is the most current causative agent of exogenous fungal nosocomial infection. This study was done to evaluate the drug susceptibility of Aspergillus flavus and A.fumigatus to itraconazole and amphotericin B. This Laboratory study was done on 25 Aspergillus fumigatus and 25 Aspergillus flavus species isolated from transplant's patients. Drug susceptibility test was done according to NCCLS M38-P document. Fungal suspensions of mentioned fungi were supplied with ranges 0.5-5x10[4] by spectrophotometer at 530 nm. Serial dilutions of drugs were supplied from 0.03125 to 16 microg/ml and MICs determined following 48h incubation at 35C. Obtained MICs ranges for Aspergillus fumigatus and Aspergillus flavus were 1-4 microg/ml and 0.5-4 micro g/ml for itraconazole, respectively while MICs ranges against Aspergillus fumigatus and Aspergillus flavus were 0.5-2 micro g/ml and 0.25-2 microg/ml for amphotericin B, respectively. Amphotericin B MICs were significantly lower than itraconazole [P<0.05]. Aspergillus flavus and A.fumigatus were susceptible to amphotericin B and itraconazole

[ in vitro antifungal effects of Aran extract [Hypericum Perforatum]

The aim of present study was to investigate the antifungal activity of Hypericum perforatum extract in vitro. Three extraction techniques were used [chloroform, acetone and methanol solvents] and the extracts were tested against Fusarium chlamydosporum, Aspergillus niger, Aspergillus fumigatm, Aspergillus flavus. Acetone extract of H. perforatum was the most active against the growth of F. chlamydosporum, A. niger, it caused 55% and 40% inhibition of fungus growth, respectively, when used in a concentration of 7.5 mg/ml from growth media. The fungus A. flavus was more sensitive to the chloroform extract of H. perforatum and the inhibition percentage was 53.84% at the extract concentration of 7.5 mg/ml from growth media. The concentration 7.5 mg/ml of culture media for all extracts was more effective than the concentration 2.5 mg/ml from growth media. It was concluded that the acetone extract of H. perforatum showed a broad spectrum and greatest activity against the fungi among extracts tested

Secretion of Streptomyces tendae antifungal protein 1 by Lactococcus lactis

Lactococcus lactis, the model lactic acid bacterium, is a good candidate for heterologous protein production in both foodstuffs and the digestive tract. We attempted to produce Streptomyces tendae antifungal protein 1 (Afp1) in L. lactis with the objective of constructing a strain able to limit fungal growth. Since Afp1 activity requires disulfide bond (DSB) formation and since intracellular redox conditions are reportedly unfavorable for DSB formation in prokaryotes, Afp1 was produced as a secreted form. An inducible expression-secretion system was used to drive Afp1 secretion by L. lactis; Afp1 was fused or not with LEISSTCDA, a synthetic propeptide (LEISS) that has been described to be a secretion enhancer. Production of Afp1 alone was not achieved, but production of LEISS-Afp1 was confirmed by Western blot and immunodetection with anti-Afp1 antibodies. This protein (molecular mass: 9.8 kDa) is the smallest non-bacteriocin heterologous protein ever reported to be secreted in L. lactis via the Sec-dependent pathway. However, no anti-fungal activity was detected, even in concentrated samples of induced supernatant. This could be due to a too low secretion yield of Afp1 in L. lactis, to the absence of DSB formation, or to an improper DSB formation involving the additional cysteine residue included in LEISS propeptide. This raises questions about size limits, conformation problems, and protein secretion yields in L. lactis.

Allergic bronchopulmonary aspergillosis--a case report.

A 24 years old male presented with recurrent symptoms of cough and breathlessness for 6 years but increased in past 6 months. Fleeting radiological opacities, peripheral eosinophilia and central type bronchiectasus in high resolution CT scan gave the suspicion of allergic bronchopolmonary aspergilosis. Confirmation of the diagnosis was done by skin prick and immunological tests. The patient showed an excellent response to oral prednisolone.

Acción antimicótica in vitro de hojas y ramitas de canelo (drimys winteri j. r. & g. forster) / In vitro antimycotic action of leaves and twigs of canelo (drimys winteri j. r. & g. forster)

La decocción y el extracto en acetato de etilo de hojas y ramitas trozadas de canelo (drimys winteri) inhibieron el desarrollo in vitro de candida albicans, aspergillus niger, a. fumigatus, rhizopus oryzae, mucor racemosus y m. hiemalis

Comparative in vitro and in vivo evaluation of himachalol in murine invasive aspergillosis.

Aspergilli are increasingly important infections in immunocompromised patients (ICP). The available antifungals often cause discrepancies in laboratory determination of MICs and a correlation in therapy. An effort was made to compare in vitro techniques for testing of antifungals, viz. polyenes, imidazoles, 5-fluorocytosine, amorolfine; and screened a phytoproduct- himachalol (a sesquiterpene alcohol) from Cedrus deodara (Roxb.) Loud against A. fumigatus clinical isolates (24) by macrobroth two-fold seal dilution (TFSD), microbroth microtitre (MT) and disc diffusion (DD) techniques using various broth/agar media at varying periods of incubation. The best activity in terms of geometric mean (GM) (GM.MIC < 0.39 microgrmas ml-1) was obtained with SCZ in the broth by both MT or TFSD technique followed by ECZ (GM.MIC 0.39 micrograms ml-1) and ITZ (GM.MIC 0.39-0.8 micrograms ml-1) in RPMI-1640. Overall RPMI-1640 was found to be the most suitable growth medium for testing of azoles or amorolfine, and YNB for polyene and 5-FC. MT technique was the most sensitive quantitative, reproducible, rapid and economical compared to other techniques. The treatment of Swiss mice with himachalol (200 mg kg-1, po) once a day, for 7 days, provided 60% protection concomitantly with increased MST (15 days) against invasive aspergillosis. A combination of himachalol (200 mgkg-1) plus SCZ (5 mgkg-1) showed better regimen in the therapy evidenced by enhanced survival (80%) of mice significantly (p < 0.001) with prolonged MST (> 15 days) compared to control. The treatments also reduced cfu (mean log10) burden of A. fumigatus from kidney.

Antifungal activity of conjugated styryl ketones.

The susceptibility of Aspergillus fumigatus to a series of alpha, beta-unsaturated styryl ketones known to be thiol-alkylators was examined, and the results were compared with those obtained for Candida albicans. Among 13 compounds used in our study, one (designated NC1110) inhibited the growth of A. fumigatus completely at low concentrations (minimum inhibitory concentration = 32 microM). Structure-activity analysis of these compounds indicated that the electron attracting property as well as the overall hydrophobicity of the compounds are important parameters for their antifungal activity. These preliminary results suggest that further modification of these molecules to enhance their hydrophobicity and the electron attracting property may result in more active compounds with improved antifungal activity.

Aspergilosis broncopulmonar: consideraciones sobre 122 casos con serología positiva para Aspergillus fumigatus / Bronchopulmonar aspergillosis: 122 cases diagnosed by serological tests for A. fumigatus

Se presenta el análisis de 122 casos de aspergilosis broncopulmonar diagnosticados entre los años 1990 y 1994, en el Departamento de Micología del Instituto Nacional de Higiene y Medicina Tropical de Guayaquil. Todos ellos presentaban anticuerpos frente al antígeno de A. fumigatus demostrables por inmunodifusión por la técnica de Ouchterlony. El estudio micológico en muestras de esputo fue realizado en 60 enfermos. Se señalan los parámetros considerados para el diagnóstico, las lesiones radiológicas observadas y los tratamientos instituídos

Acción antifúngica de las asociaciones de sulfametoxazol o ketoconazol con etosuccimida, fenilbutazona, ibuprofeno, gentamicina, metamizol, yoduro de potasio y otros fármacos / Antifungal action of the association among sulphametoxazole or ketoconazole and ethosuccimide, phenylbutazone, ibuprofen, gentamycin, metamizol, potassium iodide and other drugs

Se obtuvo la inhibición total del desarrollo fúngico in vitro durante 48 o más horas, al agregar al medio de cultivo los fármacos siguientes: para Acremonium potronii y A. falciforme 50 ug/ml de sulfametoxazol; para Fusarium solanii sulfametoxazol 100 ug/ml más fenilbutazona 30 ug/ml más etosuccimida 100 ug/ml o sulfametoxazol 100 ug/ml mas ibuprofeno 30 ug/ml más etosuccimida 100 ug/ml; para Candida albicans y Aspergillus niger ketoconazol 0.5 ug/ml más gentamicina 3-10 ug/ml; para A. fumigatus sulfametoxazol 100 ug/ml más yoduro de potasio 100 ug/ml más metamizol 100 ug/ml o sulfametoxazol 80-100 ug/ml más fenilbutazona 20-30 ug/ml más etosuccimida 100 ug/ml; o sulfametoxazol 80 ug/ml más clorpromacina 10 ug/ml