Trends in Azole resistance in Aspergillus fumigatus, The Netherlands, 1994–2016

We investigated azole resistance in Aspergillus fumigatus in a tertiary reference hospital in the Netherlands during 1994–2016. The 5-year patient-adjusted proportion of resistance increased from 0.79% for 1996–2001 to 4.25% for 2002–2006, 7.17% for 2007–2011, and 7.04% for 2012–2016. However, we observed substantial variation between years.</p

In Vitro Susceptibility of Pythium insidiosum to Macrolides and Tetracycline Antibiotics ▿

We describe the in vitro activity of macrolides and tetracycline antibiotics against Pythium insidiosum. The MICs were determined according to CLSI procedures (visual MIC) and by a colorimetric method [3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT)]. The lowest geometric mean (GM) MIC (MICs in μg/ml) (0.39 and 0.7 by visual reading and colorimetric method, respectively) and MIC ranges (0.125 to 2.0) were obtained for minocycline, while the highest MICs were shown for erythromycin (GM of 7.58 and 12.25 by visual reading and colorimetric method, respectively, and MIC ranged from 2 to 32). This significant in vitro activity makes these classes of antibiotics good candidates for experimental treatment of pythiosis

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.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

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.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

Antifungal activities of tacrolimus in combination with antifungal agents against fluconazole-susceptible and fluconazole-resistant Trichosporon asahii isolates

The antifungal activity of tacrolimus in combination with antifungal agents against different fungal species has been previously reported. Here we report the in vitro interactions between tacrolimus and amphotericin B, fluconazole, itraconazole, and caspofungin against 30 clinical isolates of both fluconazole-susceptible and fluconazole-resistant Trichosporon asahii. For these analyses, we used the broth microdilution method based on the M27-A3 technique and checkerboard microdilution method. Tacrolimus showed no activity against T. asahii strains (minimal inhibitory concentrations, MICs > 64.0 μg mL−1). However, a larger synergistic interaction was observed by the combinations tacrolimus + amphotericin B (96.67%) and tacrolimus + caspofungin (73.33%) against fluconazole-susceptible isolates. Combinations with azole antifungal agents resulted in low rates of synergism for this group (fluconazole + tacrolimus = 40% and itraconazole + tacrolimus = 10%). Antagonistic interactions were not observed. For the fluconazole-resistant T. asahii group, all tested combinations showed indifferent interactions. The synergism showed against fluconazole-susceptible T. asahii isolates suggests that the potential antifungal activity of tacrolimus deserves in vivo experimental investigation, notably, the combination of tacrolimus with amphotericin B or caspofungin. Keywords: Susceptibility, FK506, Resistance, Synergis