We investigated seed dormancy among species of Melastomataceae from Neotropical montane vegetation of Brazil. Four out of 50 studied species had dormant seeds:Miconia corallina(Miconieae), Tibouchina cardinalis(Melastomeae), Comolia sertularia(Melastomeae) andChaetostoma armatum(Microlicieae). For these four species, germinability of seeds collected in different years was always < 10% and the percentages of embryoless seeds and non-viable embryos were both insufficient to explain low or null germinability. This is the first unequivocal report of seed dormancy in tropical Melastomataceae. The production of seeds with permeable seed coats and fully developed, differentiated embryos indicates the occurrence of physiological dormancy. The reconstructed phylogenetic tree of the 50 species suggests that physiological dormancy evolved multiple times during the evolutionary history of Melastomataceae in this vegetation. Physiological dormancy evolved in species and populations associated with xeric microhabitats, where seeds are dispersed in unfavourable conditions for establishment. Therefore, drought-induced mortality may have been a strong selective pressure favouring the evolution of physiological dormancy in Melastomataceae. We argue that dormancy may have been independently selected in other lineages of Cerrado plants colonizing xeric microhabitats and dispersing seeds at the end of the rainy season. The contributions of our data to the understanding of seed dormancy in tropical montane vegetation are discussed.

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Fruits of Melastomataceae constitute a key resource for Neotropical frugivores. However, the mechanisms determining gut-passage effects on seed germination are poorly known. Here, we determine how bird gut-passage affects seed germination in three species of Miconieae by running germination experiments, examining changes in seed coat structure and determining germination inhibition by fruit extracts. Mature fruits of Clidemia urceolata, Leandra aurea and Miconia rubiginosa were sampled in south-eastern Brazil and seeds were submitted to treatments evaluating gut-passage effects and different concentrations of fruit extracts. Light and scanning electron microscopy were used to compare seed coat structure and thickness of control and gut-passed seeds. We found minor effects of gut passage on seed germination. However, changes in seed coat structure of gut-passed seeds of L. aurea may have been related to a decrease in germination. Our data also support the idea that germination inhibitors in fruit pulp may contribute to the inhibition effect. Our study corroborates the idea that changes in the seed coat following gut passage modulate the complex fruit–frugivore interactions, especially between plants and generalist dispersers, and that seed cleaning is a key factor determining seedling establishment in Neotropical Melastomataceae.

Introdução: O ambiente da UTI é considerado o foco das infecções relacionadas à assistência à saúde (IRAS). Isso deve-se a particularidades desse ambiente como a utilização de dispositivos invasivos, uso de imunossupressores, período de internação prolongado, colonização por micro-organismos resistentes, prescrição de antimicrobianos e a própria característica do ambiente da UTI, além da condição clínica do paciente. O conhecimento do perfil bacteriano de cada cultura norteia a equipe médica no tratamento inicial das infecções. Objetivo: O objetivo desse trabalho foi verificar a ocorrência e o perfil bacteriano presente em pacientes internados na UTI de um hospital universitário. Material e métodos: O estudo foi realizado através da análise de exames de secreções traqueais, hemoculturas e uroculturas de pacientes internados no período de janeiro a junho de 2018. Os dados foram coletados por meio de impressos laboratoriais do próprio serviço e tabulados na planilha do Excel®, sendo divididos em amostras positivas e negativas, e realizada análise descritiva com valores absolutos e percentuais. Resultados: Em geral, as bactérias de maior ocorrência foram Acinetobacter baumannii (20,3%), Pseudomonas aeruginosa (19,7%), Klebsiella pneumoniae (15,1%), Staphylococcus aureus (11,9%), Staphylococcus coagulase negativa (7,2%) e Escherichia coli (5,7%). As espécies bacterianas com maior resistência foram Acinetobacter baumanni, Klebisiella pneumoniae, aPseudomonas aeruginosa, Eschericia coli, Serratia marcencens e Enterobacter cloacae. Conclusão: Os dados deste trabalho permitem o conhecimento do perfil bacteriano encontrado nos pacientes internados, o que poderá nortear o tratamento das infecções e consequentemente diminuir a seleção de bactérias multirresistentes, auxiliando na prevenção e no controle das infecções hospitalares.