Browsing by Author "Stevens, David A"
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- Aspergillosis in albatrossesPublication . Melo, Aryse Martins; Silva Filho, Rodolfo Pinho da; Poester, Vanice Rodrigues; Fernandes, Cristina Gevehr; von Groll, Andrea; Stevens, David A; Sabino, Raquel; Xavier, Melissa OrzechowskiAspergillosis is a respiratory fungal disease of importance in captive marine birds. The aim of this study was to describe the occurrence of aspergillosis in Thalassarche melanophris during rehabilitation events and to identify the etiological agent. All the albatrosses that were received for rehabilitation and died within a 2-year period were included in the study. The proportionate mortality rate caused by aspergillosis was 21.4% (3/14). One of the etiological agents was Aspergillus flavus/oryzae lineage, and the other was A. fumigatus sensu stricto. Our study suggests that aspergillosis can act as a limiting factor in the rehabilitation of albatrosses.
- Aspergillosis in albatrossesPublication . Melo, Aryse Martins; Silva Filho, Rodolfo Pinho da; Poester, Vanice Rodrigues; Fernandes, Cristina Gevehr; von Groll, Andrea; Stevens, David A; Sabino, Raquel; Xavier, Melissa OrzechowskiAspergillosis is a respiratory fungal disease of importance in captive marine birds. The aim of this study was to describe the occurrence of aspergillosis in Thalassarche melanophris during rehabilitation events and to identify the etiological agent. All the albatrosses that were received for rehabilitation and died within a 2-year period were included in the study. The proportionate mortality rate caused by aspergillosis was 21.4% (3/14). One of the etiological agents was Aspergillus flavus/oryzae lineage, and the other was A. fumigatus sensu stricto. Our study suggests that aspergillosis can act as a limiting factor in the rehabilitation of albatrosses.
- Aspergillosis, Avian Species and the One Health Perspective: The Possible Importance of Birds in Azole ResistancePublication . Melo, Aryse Martins; Stevens, David A; Tell, Lisa A; Veríssimo, Cristina; Sabino, Raquel; Xavier, Melissa OrzechowskiThe One Health context considers health based on three pillars: humans, animals, and environment. This approach is a strong ally in the surveillance of infectious diseases and in the development of prevention strategies. Aspergillus spp. are fungi that fit substantially in this context, in view of their ubiquity, as well as their importance as plant pathogens, and potentially fatal pathogens for, particularly, humans and avian species. In addition, the emergence of azole resistance, mainly in Aspergillus fumigatus sensu stricto, and the proven role of fungicides widely used on crops, reinforces the need for a multidisciplinary approach to this problem. Avian species are involved in short and long distance travel between different types of landscapes, such as agricultural fields, natural environments and urban environments. Thus, birds can play an important role in the dispersion of Aspergillus, and of special concern, azole-resistant strains. In addition, some bird species are particularly susceptible to aspergillosis. Therefore, avian aspergillosis could be considered as an environmental health indicator. In this review, aspergillosis in humans and birds will be discussed, with focus on the presence of Aspergillus in the environment. We will relate these issues with the emergence of azole resistance on Aspergillus. These topics will be therefore considered and reviewed from the "One Health" perspective.
- Diphenyl diselenide and its interaction with antifungals against Aspergillus sppPublication . Melo, Aryse Martins; Poester, Vanice Rodrigues; Trapaga, Mariana; Nogueira, Cristina Wayne; Zeni, Gilson; Martinez, Marife; Sass, Gabriele; Stevens, David A; Xavier, Melissa OrzechowskiGiven the few antifungal classes available to treat aspergillosis, this study aimed to evaluate the in vitro antifungal activity of diphenyl diselenide (PhSe)2 alone and in combination with classical antifungals against Aspergillus spp., and its in vivo activity in a systemic experimental aspergillosis model. We performed in vitro broth microdilution assay of (PhSe)2 against 32 Aspergillus isolates; and a checkboard assay to test the interaction of this compound with itraconazole (ITC), voriconazole (VRC), amphotericin B (AMB), and caspofungin (CAS), against nine Aspergillus isolates. An experimental model of invasive aspergillosis in mice was studied, and survival curves were compared between an untreated group and groups treated with 100 mg/kg ITC, or (PhSe)2 in different dosages (10 mg/kg, 50 mg/kg and 100 mg/kg). All Aspergillus non-fumigatus and 50% of A. fumigatus were inhibited by (PhSe)2 in concentrations ≤ 64 µg/ml, with significant differences in MICs between the sections. Synergism or additive effect in the in vitro (PhSe)2 interaction with VRC and CAS was observed against the majority of isolates, and with ITC against the non-fumigatus strains. In addition to the inhibitory interaction, (PhSe)2 was able to add a fungicidal effect to CAS. Survival curves from the systemic experimental aspergillosis model demonstrated that the inoculum caused an acute and lethal infection in mice, and no treatment applied significantly prolonged survival over that of the control group. The results highlight the promising activity of (PhSe)2 against Aspergillus species, but more in vivo studies are needed to determine its potential applicability in aspergillosis treatment.
- Molecular epidemiology of aspergillosis in Magellanic penguins and susceptibility patterns of clinical isolatesPublication . Melo, Aryse Martins; Poester, Vanice Rodrigues; Canabarro, Paula Lima; Sampaio, Daniel Ataíde; Stevens, David A; Veríssimo, Cristina; Sabino, Raquel; Xavier, Melissa OrzechowskiAspergillus 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.