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1.
Bioresour Technol ; 406: 130982, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38879055

RESUMO

Cotreatment, mechanical disruption of lignocellulosic biomass during microbial fermentation, is a potential alternative to thermochemical pretreatment as a means of increasing the accessibility of lignocellulose to biological attack. Successful implementation of cotreatment requires microbes that can withstand milling, while solubilizing and utilizing carbohydrates from lignocellulose. In this context, cotreatment with thermophilic, lignocellulose-fermenting bacteria has been successfully evaluated for a number of lignocellulosic feedstocks. Here, cotreatment was applied to sugarcane bagasse using monocultures of the cellulose-fermenting Clostridium thermocellum and cocultures with the hemicellulose-fermenting Thermoanaerobacterium thermosaccharolyticum. This resulted in 76 % carbohydrate solubilization (a 1.8-fold increase over non-cotreated controls) on 10 g/L solids loading, having greater effect on the hemicellulose fraction. With cotreatment, fermentation by wild-type cultures at low substrate concentrations increased cumulative product formation by 45 % for the monoculture and 32 % for the coculture. These findings highlight the potential of cotreatment for enhancing deconstruction of sugarcane bagasse using thermophilic bacteria.


Assuntos
Celulose , Técnicas de Cocultura , Fermentação , Saccharum , Solubilidade , Saccharum/química , Celulose/metabolismo , Celulose/química , Clostridium thermocellum/metabolismo , Thermoanaerobacterium/metabolismo , Lignina/metabolismo , Lignina/química , Bactérias Anaeróbias/metabolismo
2.
Rev Paul Pediatr ; 38: e2018258, 2020.
Artigo em Inglês, Português | MEDLINE | ID: mdl-32159644

RESUMO

OBJECTIVE: To highlight the pathogenicity of Streptococcus anginosus, which is rare in pediatric patients, but can cause severe infections that are known to have a better outcome when treated early with interventional procedures and prolonged antibiotic therapy. CASE: description: The patient is a 6-year-old boy with global developmental delay, examined in the emergency room due to fever and respiratory distress. The physical examination and diagnostic workout revealed complicated pneumonia with empyema of the left hemithorax; he started antibiotic therapy and underwent thoracic drainage. Pleural fluid cultures grew Streptococcus anginosus. On day 11, the child had a clinical deterioration with recurrence of fever, hypoxia, and respiratory distress. At this point, considering the causative agent, he was submitted to video-assisted thoracoscopic decortication, with good progress thereafter. COMMENTS: Streptococcus anginosus is a commensal bacterium of the human oral cavity capable of causing severe systemic infections. Although reports of complicated thoracic infections with this agent are rare in the pediatric population, they have been increasing in adults. Streptococcus anginosus has a high capacity to form abscess and empyema, requiring different therapeutic approaches when compared to complicated pneumonia caused by other agents.


Assuntos
Empiema Pleural/microbiologia , Pneumonia Bacteriana/microbiologia , Infecções Estreptocócicas/complicações , Streptococcus anginosus , Antibacterianos/uso terapêutico , Criança , Drenagem , Empiema Pleural/diagnóstico por imagem , Empiema Pleural/terapia , Humanos , Masculino , Transtornos do Neurodesenvolvimento/complicações , Pneumonia Bacteriana/diagnóstico por imagem , Pneumonia Bacteriana/terapia , Infecções Estreptocócicas/diagnóstico por imagem , Infecções Estreptocócicas/terapia , Cirurgia Torácica Vídeoassistida
3.
Artigo em Inglês | LILACS | ID: biblio-1092151

RESUMO

ABSTRACT Objective: To highlight the pathogenicity of Streptococcus anginosus, which is rare in pediatric patients, but can cause severe infections that are known to have a better outcome when treated early with interventional procedures and prolonged antibiotic therapy. Case description: The patient is a 6-year-old boy with global developmental delay, examined in the emergency room due to fever and respiratory distress. The physical examination and diagnostic workout revealed complicated pneumonia with empyema of the left hemithorax; he started antibiotic therapy and underwent thoracic drainage. Pleural fluid cultures grew Streptococcus anginosus. On day 11, the child had a clinical deterioration with recurrence of fever, hypoxia, and respiratory distress. At this point, considering the causative agent, he was submitted to video-assisted thoracoscopic decortication, with good progress thereafter. Comments: Streptococcus anginosus is a commensal bacterium of the human oral cavity capable of causing severe systemic infections. Although reports of complicated thoracic infections with this agent are rare in the pediatric population, they have been increasing in adults. Streptococcus anginosus has a high capacity to form abscess and empyema, requiring different therapeutic approaches when compared to complicated pneumonia caused by other agents.


RESUMO Objetivo: Alertar para a patogenicidade do Streptococcus anginosus que, apesar de raro em pediatria, pode causar infeções graves que necessitam de tratamento invasivo e antibioterapia de longo curso para obter um melhor prognóstico. Descrição do caso: Criança de seis anos, com atraso do desenvolvimento psicomotor, avaliado no serviço de urgência por febre e dificuldade respiratória. O exame físico, juntamente com os exames complementares, revelou uma pneumonia complicada com empiema no hemitórax esquerdo, tendo iniciado antibioterapia e sido submetido à drenagem do líquido pleural. Foi identificado Streptococcus anginosus nesse líquido. No 11º dia de doença, a criança agravou o seu estado clínico, com recidiva da febre, hipoxemia e dificuldade respiratória. Considerando-se o microrganismo identificado, o paciente foi submetido à decorticação pulmonar por videotoracoscopia, com boa evolução clínica posterior. Comentários: Streptococcus anginosus é uma bactéria comensal da cavidade oral humana, que pode causar infecções sistêmicas graves. Apesar de serem raros os casos descritos em pediatria, têm sido cada vez mais descritas infecções torácicas complicadas em adultos. Esse microrganismo também tem a capacidade de formar abcessos e empiemas, que precisam de intervenções terapêuticas diferentes, quando comparados a pneumonias complicadas causadas por outros agentes.


Assuntos
Humanos , Masculino , Criança , Infecções Estreptocócicas/complicações , Empiema Pleural/microbiologia , Pneumonia Bacteriana/microbiologia , Streptococcus anginosus , Infecções Estreptocócicas/terapia , Infecções Estreptocócicas/diagnóstico por imagem , Drenagem , Empiema Pleural/terapia , Empiema Pleural/diagnóstico por imagem , Pneumonia Bacteriana/terapia , Pneumonia Bacteriana/diagnóstico por imagem , Cirurgia Torácica Vídeoassistida , Transtornos do Neurodesenvolvimento/complicações , Antibacterianos/uso terapêutico
4.
Braz. j. infect. dis ; Braz. j. infect. dis;17(1): 102-105, Jan.-Feb. 2013. ilus
Artigo em Inglês | LILACS | ID: lil-665782

RESUMO

Posaconazole Histoplasmosis Salvage therapy African histoplasmosis is a granulomatous mycosis caused by Histoplasma capsulatum var. duboisii. Treatment is usually extrapolated from guidelines for classical histoplasmosis, and includes 2-4 weeks of amphotericin B followed by a step-down maintenance therapy with itraconazole. Pediatric usage of posaconazole, an oral second-generation azole, remains off-label, but recent surveys show that it is safe and well tolerated in children. We report a case of disseminated African histoplasmosis in a 12-year-old boy from Guinea-Bissau. Therapy with amphotericin B and itraconazole led to a progressive clinical deterioration. A dramatic and lasting improvement was observed using posaconazole. He completed 12 months of therapy. No relapse was noted during or 3 months after treatment. We report that posaconazole may be a safe and efficacious drug in the salvage management of disseminated AH, either in patients with disease refractory to conventional anti-fungal therapy, or in patients whose serious adverse effects of first-line drugs preclude its use.


Assuntos
Criança , Humanos , Masculino , Antifúngicos/uso terapêutico , Histoplasmose/tratamento farmacológico , Terapia de Salvação/métodos , Triazóis/uso terapêutico , Histoplasmose/patologia , Resultado do Tratamento
5.
Braz J Infect Dis ; 17(1): 102-5, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23312726

RESUMO

African histoplasmosis is a granulomatous mycosis caused by Histoplasma capsulatum var. duboisii. Treatment is usually extrapolated from guidelines for classical histoplasmosis, and includes 2-4 weeks of amphotericin B followed by a step-down maintenance therapy with itraconazole. Pediatric usage of posaconazole, an oral second-generation azole, remains off-label, but recent surveys show that it is safe and well tolerated in children. We report a case of disseminated African histoplasmosis in a 12-year-old boy from Guinea-Bissau. Therapy with amphotericin B and itraconazole led to a progressive clinical deterioration. A dramatic and lasting improvement was observed using posaconazole. He completed 12 months of therapy. No relapse was noted during or 3 months after treatment. We report that posaconazole may be a safe and efficacious drug in the salvage management of disseminated AH, either in patients with disease refractory to conventional anti-fungal therapy, or in patients whose serious adverse effects of first-line drugs preclude its use.


Assuntos
Antifúngicos/uso terapêutico , Histoplasmose/tratamento farmacológico , Terapia de Salvação/métodos , Triazóis/uso terapêutico , Criança , Histoplasmose/patologia , Humanos , Masculino , Resultado do Tratamento
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