Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

Background: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. Results: We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. Conclusions: The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates

A alimentação do prematuro por meio do copo Cup-feeding of premature newborn children

OBJETIVO: Quantificar a proporção de leite perdido na oferta da dieta com copo; o tempo de oferta e analisar se há relação do desperdício e o tempo gasto na ingesta com as variáveis: sexo, dias de vida, idade gestacional corrigida, tempo de sonda orogástrica, tempo de alimentação por via oral, estado de vigília e sinais de estresse. MÉTODOS: Participaram 20 recém-nascidos prematuros, 11 do sexo feminino e nove do masculino. A média de idade gestacional corrigida foi de 36 semanas e o peso na avaliação de 1668 gramas. Os bebês eram alimentados via oral por, no mínimo, dois dias. Seus prontuários foram analisados quanto ao sexo, idade gestacional, peso atual, dias de vida, tempo de alimentação por via oral e tempo de uso de sonda orogástrica para relacionar aos dados da oferta da dieta. Para a administração do leite, o recém-nascido foi posicionado segundo as normas da Organização Mundial de Saúde. O alimento foi ofertado utilizando-se copo descartável de 50 mililitros, uma gaze foi colocada como anteparo e o tempo da oferta mensurado. Posteriormente, a gaze foi pesada. RESULTADOS: Houve diferença estatisticamente significante entre os volumes aceito (81,5%) e desperdiçado (22,8%) de leite, com maior aceite para o sexo feminino e para os bebês que não apresentaram sinais de estresse. O tempo médio de ingestão da dieta foi de 416 segundos. CONCLUSÕES: Os recém-nascidos pré-termo do sexo feminino aceitaram maior volume de leite, e quanto menor a exposição aos fatores estressantes, maior o aceite da dieta. O tempo médio gasto para ingestão da dieta não foi influenciado pelas variáveis analisadas.<br>PURPOSE: To quantify the milk loss ratio and the length of cup-feeding, and to analyze whether the waste and time expended in ingestion are related to the variables: sex, days of life, corrected gestational age, period of time using orogastric tube, period of time receiving oral feeding, alertness, and signs of stress. METHODS: Twenty premature newborn children, 11 female and nine male, participated on this study. The mean corrected gestational age was 36 weeks, and mean weight during evaluation was 1668 grams. The babies were orally fed for, at least, two days. Their medical files were analyzed regarding sex, gestational age, current weight, days of life, period of time receiving oral feeding, and period of time using orogastric tube, in order to relate these data with cup-feeding offer. For cup-feeding, the newborns were positioned according to World Health Organization standards. The milk administration was carried out using disposable 50-milliliters cups; gauze was placed as a shield, and the length of offer was measured. Later, the gauze was weighed. RESULTS: There was a significant statistical difference between the volumes of accepted (81.5%) and wasted (22.8%) milk, with more acceptance for female newborns and for the babies who did not present signs of stress. The mean length of cup-feeding was 416 seconds. CONCLUSION: Female preterm newborns accepted grater milk volume, and the lesser exposition to stressing factors the bigger the acceptance of milk. The mean length of ingestion was not influenced by the variables analyzed