An optimized protocol for DNA extraction in plants with a high content of secondary metabolites, based on leaves of Mimosa tenuiflora (Willd.) Poir. (Leguminosae).

Some species are characterized by a high content of tannins, alkaloids, and phenols in their leaves. These secondary metabolites are released during DNA extraction and might hinder molecular studies based on PCR (polymerase chain reaction). To provide an efficient method to extract DNA, Mimosa tenuiflora, an important leguminous plant from Brazilian semiarid region used in popular medicine and as a source of fuelwood or forage, was used. Eight procedures previously reported for plants were tested and adapted from leaf tissues of M. tenuiflora stored at -20°C. The optimized procedure in this study encompassed the utilization of phenol during deproteinization, increased concentrations of cetyltrimethylammonium bromide and sodium chloride, and a shorter period and lower temperature of incubation concerning other methods. The extracted DNA did not present degradation, and amplification via PCR was successful using ISSR, trnL, ITS, and ETS primers. Besides M. tenuiflora, this procedure was also tested and proved to be efficient in genetic studies of other plant species.

Genomic and epidemiological monitoring of yellow fever virus transmission potential.

The yellow fever virus (YFV) epidemic in Brazil is the largest in decades. The recent discovery of YFV in Brazilian Aedes species mosquitos highlights a need to monitor the risk of reestablishment of urban YFV transmission in the Americas. We use a suite of epidemiological, spatial, and genomic approaches to characterize YFV transmission. We show that the age and sex distribution of human cases is characteristic of sylvatic transmission. Analysis of YFV cases combined with genomes generated locally reveals an early phase of sylvatic YFV transmission and spatial expansion toward previously YFV-free areas, followed by a rise in viral spillover to humans in late 2016. Our results establish a framework for monitoring YFV transmission in real time that will contribute to a global strategy to eliminate future YFV epidemics.

Ocorrência de Actinobacillus pleuropneumoniae biótipo 1 em pulmões de suínos com pleuropneumonia no Norte de Portugal / Occurrence of Actinobacillus pleuropneumoniae biotype 1 in swine with pleuropneumonia in the North of Portugal

The isolation and identification of Actinobacillus pleuropneumoniae in swine lungs with pleuropneumonia in the North of Portugal were reported. A total of 127 swine lungs with and without lesions were examined. The system of lesions classification was based on a semi-quantitative method. Diagnosis was made by isolation and identification of the etiological agent in typical lesions. The occurrence of observed lesions was 75.6 percent and the occurrence of isolation of A. pleuropneumoniae was 19.7 percent. In 25 out of 96 (26.0 percent) lung samples with lesions of pleuropneumonia, A. pleuropneumoniae was isolated.