Photodynamic and Antibiotic Therapy Impair the Pathogenesis of Enterococcus faecium in a Whole Animal Insect Model

Enterococcus faecium has emerged as one of the most important pathogens in healthcare-associated infections worldwide due to its intrinsic and acquired resistance to many antibiotics, including vancomycin. Antimicrobial photodynamic therapy (aPDT) is an alternative therapeutic platform that is currently under investigation for the control and treatment of infections. PDT is based on the use of photoactive dye molecules, widely known as photosensitizer (PS). PS, upon irradiation with visible light, produces reactive oxygen species that can destroy lipids and proteins causing cell death. We employed Galleria mellonella (the greater wax moth) caterpillar fatally infected with E. faecium to develop an invertebrate host model system that can be used to study the antimicrobial PDT (alone or combined with antibiotics). In the establishment of infection by E. faecium in G. mellonella, we found that the G. mellonella death rate was dependent on the number of bacterial cells injected into the insect hemocoel and all E. faecium strains tested were capable of infecting and killing G. mellonella. Antibiotic treatment with ampicillin, gentamicin or the combination of ampicillin and gentamicin prolonged caterpillar survival infected by E. faecium (P = 0.0003, P = 0.0001 and P = 0.0001, respectively). In the study of antimicrobial PDT, we verified that methylene blue (MB) injected into the insect followed by whole body illumination prolonged the caterpillar survival (P = 0.0192). Interestingly, combination therapy of larvae infected with vancomycin-resistant E. faecium, with antimicrobial PDT followed by vancomycin, significantly prolonged the survival of the caterpillars when compared to either antimicrobial PDT (P = 0.0095) or vancomycin treatment alone (P = 0.0025), suggesting that the aPDT made the vancomycin resistant E. faecium strain more susceptible to vancomycin action. In summary, G. mellonella provides an invertebrate model host to study the antimicrobial PDT and to explore combinatorial aPDT-based treatments.

Contrasting engineering effects of leaf-rolling caterpillars on a tropical mite community

Ecosystem engineers are organisms that change the physical structure of environments and provide habitats for other organisms. Lepidopteran caterpillars may act as ecosystem engineers by rolling leaves as shelters to complete metamorphosis. After being abandoned, these structures may provide shelter for other organisms. In this study, the influence of leaf-rolling caterpillars on tropical mite communities was reported. Expanded leaves and leaves rolled by larvae and also developed field experiments using leaves rolled manually with different shapes and sizes (i.e. different architectures) in different seasons were surveyed (dry and rainy). While the abundance and diversity of predatory mites were higher in rolled leaves, the abundance of phytophages decreased in these leaves. Species composition differed between rolled and expanded leaves. The structure of shelters affected the distribution of predatory mites, with higher abundances found on funnel-shaped leaves. Predatory mites only benefited from the rolled leaves in the dry season. This is the first study showing (i) the contrasting effects of ecosystem engineers on microarthropod communities, favouring some feeding guilds and inhibiting others; (ii) that the shape of rolled leaves has variable effects on mite communities; and (iii) that facilitation was temporally dependent, i.e. occurred only in the dry season. © 2013 The Royal Entomological Society.

Engenheiros dos ecossistemas em plantas: modificações arquiteturais de folhas por largatas de Lepidoptera influenciam a estrutura de comunidades de artrópodes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comportamento de variedades de soja em condições de solo compactado e níveis de irrigação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de um perfilômetro laser para determinação da área e volume de contato entre o pneu e o solo: Cristiano Alberto de Paula. -

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinação do rendimento na barra de tração de tratores agrícolas com tração dianteira auxiliar (4x2 Tda)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação ergonômica dos controles e mostradores do posto de trabalho do operador de tratores

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Desempenho operacional da colheita mecanizada de cana-de-açúcar (saccharum spp.) em função da velocidade de deslocamento e rotação do motor da colhedora

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Desempenho de um trator agrícola em função do desgaste das garras dos pneus e das condições superficiais do solo

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Modelo computacional para dimensionamento de tratores, equipamentos e operações agrícolas

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Eficácia da soja geneticamente modificada MON 87701 × MON 89788 com a expressão da proteína Cry1Ac no controle de Anticarsia gemmatalis (Hübner) e Pseudoplusia includens (Walker) (Lepidoptera: Noctuidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Resistência de cultivares de amendoim de hábitos de crescimento ereto e rasteiro a Spodoptera frugiperda, em laboratório

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cobertura da cultura da soja e deposição de insiticida aplicado com e sem adjuvante e diferentes equipamentos e volumes de calda

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Expressão dos genes Vip3Aa e Cry1Ia em Escherichia coli efetivos no controle de Spodoptera frugiperda

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização da Associação dos Pequenos Agricultores no contexto do Projeto Cinturão Verde de Ilha Solteira - SP

Pós-graduação em Geografia - FCT