RESUMO
Mucorales can cause cutaneous to deep-seated infections, mainly in the immunocompromised host, resulting in high mortality rates due to late and inefficient treatment. In this study, Galleria mellonella larvae were evaluated as a heterologous invertebrate host to study pathogenicity of clinically relevant mucormycetes (Rhizopus spp., Rhizomucor spp., Lichtheimia spp., Mucor spp.). All tested species were able to infect G. mellonella larvae. Virulence potential was species-specific and correlated to clinical relevance. Survival of infected larvae was dependent on (a) the species (growth speed and spore size), (b) the infection dose, (c) the incubation temperature, (d) oxidative stress tolerance, and (e) iron availability in the growth medium. Moreover, we exploited the G. mellonella system to determine antifungal efficacy of liposomal amphotericin B, posaconazole, isavuconazole, and nystatin-intralipid. Outcome of in vivo treatment was strongly dependent upon the drug applied and the species tested. Nystatin-intralipid exhibited best activity against Mucorales, followed by posaconazole, while limited efficacy was seen for liposomal amphotericin B and isavuconazole. Pharmacokinetic properties of the tested antifungals within this alternative host system partly explain the limited treatment efficacy. In conclusion, G. mellonella represents a useful invertebrate infection model for studying virulence of mucormycetes, while evaluation of treatment response was limited.
Assuntos
Antifúngicos/uso terapêutico , Modelos Animais de Doenças , Larva/microbiologia , Lepidópteros/microbiologia , Mucorales/efeitos dos fármacos , Mucorales/patogenicidade , Mucormicose/tratamento farmacológico , Anfotericina B/farmacocinética , Anfotericina B/uso terapêutico , Animais , Antifúngicos/farmacocinética , Farmacorresistência Fúngica , Testes de Sensibilidade Microbiana , Mucor/efeitos dos fármacos , Mucor/patogenicidade , Mucormicose/microbiologia , Nitrilas/farmacocinética , Nitrilas/uso terapêutico , Piridinas/farmacocinética , Piridinas/uso terapêutico , Rhizopus/efeitos dos fármacos , Rhizopus/patogenicidade , Triazóis/farmacocinética , Triazóis/uso terapêutico , VirulênciaRESUMO
BACKGROUND: Considerable disparities exist in the provision of paediatric renal replacement therapy (RRT) across Europe. This study aims to determine whether these disparities arise from geographical differences in the occurrence of renal disease, or whether country-level access-to-care factors may be responsible. METHODS: Incidence was defined as the number of new patients aged 0-14 years starting RRT per year, between 2007 and 2011, per million children (pmc), and was extracted from the ESPN/ERA-EDTA registry database for 35 European countries. Country-level indicators on macroeconomics, perinatal care and physical access to treatment were collected through an online survey and from the World Bank database. The estimated effect is presented per 1SD increase for each indicator. RESULTS: The incidence of paediatric RRT in Europe was 5.4 cases pmc. Incidence decreased from Western to Eastern Europe (-1.91 pmc/1321 km, P < 0.0001), and increased from Southern to Northern Europe (0.93 pmc/838 km, P = 0.002). Regional differences in the occurrence of specific renal diseases were marginal. Higher RRT treatment rates were found in wealthier countries (2.47 pmc/10 378 GDP per capita, P < 0.0001), among those that tend to spend more on healthcare (1.45 pmc/1.7% public health expenditure, P < 0.0001), and among countries where patients pay less out-of-pocket for healthcare (-1.29 pmc/11.7% out-of-pocket health expenditure, P < 0.0001). Country neonatal mortality was inversely related with incidence in the youngest patients (ages 0-4, -1.1 pmc/2.1 deaths per 1000 births, P = 0.10). Countries with a higher incidence had a lower average age at RRT start, which was fully explained by country GDP per capita. CONCLUSIONS: Inequalities exist in the provision of paediatric RRT throughout Europe, most of which are explained by differences in country macroeconomics, which limit the provision of treatment particularly in the youngest patients. This poses a challenge for healthcare policy makers in their aim to ensure universal and equal access to high-quality healthcare services across Europe.
Assuntos
Acessibilidade aos Serviços de Saúde , Disparidades em Assistência à Saúde , Falência Renal Crônica/terapia , Transplante de Rim/estatística & dados numéricos , Terapia de Substituição Renal/estatística & dados numéricos , Adolescente , Criança , Pré-Escolar , Europa (Continente)/epidemiologia , Feminino , Geografia , Necessidades e Demandas de Serviços de Saúde , Humanos , Incidência , Lactente , Recém-Nascido , Falência Renal Crônica/epidemiologia , Transplante de Rim/mortalidade , Masculino , Sistema de Registros , Terapia de Substituição Renal/mortalidade , Taxa de SobrevidaRESUMO
The polyene antifungal amphotericin B (AmB) is widely used to treat life-threatening fungal infections. Even though AmB resistance is exceptionally rare in fungi, most Aspergillus terreus isolates exhibit an intrinsic resistance against the drug in vivo and in vitro. Heat shock proteins perform a fundamental protective role against a multitude of stress responses, thereby maintaining protein homeostasis in the organism. In this study, we elucidated the role of heat shock protein 70 (Hsp70) family members and compared resistant and susceptible A. terreus clinical isolates. The upregulation of cytoplasmic Hsp70 members at the transcriptional as well as translational levels was significantly higher with AmB treatment than without AmB treatment, particularly in resistant A. terreus isolates, thereby indicating a role of Hsp70 proteins in the AmB response. We found that Hsp70 inhibitors considerably increased the susceptibility of resistant A. terreus isolates to AmB but exerted little impact on susceptible isolates. Also, in in vivo experiments, using the Galleria mellonella infection model, cotreatment of resistant A. terreus strains with AmB and the Hsp70 inhibitor pifithrin-µ resulted in significantly improved survival compared with that achieved with AmB alone. Our results point to an important mechanism of regulation of AmB resistance by Hsp70 family members in A. terreus and suggest novel drug targets for the treatment of infections caused by resistant fungal isolates.