Morpho-biometrical characterisation of Portuguese Bursaphelenchus xylophilus isolates with mucronate, digitate or round tailed females

Morpho-biometrical studies were conducted on 12 Bursaphelenchus xylophilus isolates collected from maritime pine, Pinus pinaster, in Portugal. The studies were carried out on 20 females and 20 males from each isolate. A wide variation in the female tails, from round, digitate to mucronate was detected in all isolates, confirming the occurrence of mucronate tails in some females of B. xylophilus. The presence of mucronate tailed females in the Portuguese isolates of B. xylophilus clearly makes the identification of B. xylophilus by this morphological character difficult since other non-pathogenic Bursaphelenchus species also have mucronate tailed females. Amplification of satellite DNA of single specimens using species-specific primers confirmed the identity of the mucronate tailed females in the Portuguese isolates as B. xylophilus. The satellite DNA technique was also useful in the identification of juveniles of B. xylophilus from P. pinaster wood samples

Is there still room to explore cyclodextrin glycosyltransferase-producers in Brazilian biodiversity?

In the present work, different Brazilian biomes aiming to identify and select cyclodextrin glycosyltransferase-producer bacteria are explored. This enzyme is responsible for converting starch to cyclodextrin, which are interesting molecules to carry other substances of economic interest applied by textile, pharmaceutical, food, and other industries. Based on the enzymatic index, 12 bacteria were selected and evaluated, considering their capacity to produce the enzyme in culture media containing different starch sources. It was observed that the highest yields were presented by the bacteria when grown in cornstarch. These bacteria were also characterized by sequencing of the 16S rRNA region and were classified as Bacillus, Paenibacillus, Gracilibacillus and Solibacillus.publishersversionpublishe

Biochemical and Molecular Characterization of Plant-Parasitic Nematodes

Nematologists need correct species identification to carry out research, teaching, extension and other activities. Therefore, nematode taxonomy must be pursued diligently at all levels. The identification of plant-parasitic nematodes is not always easy and that of some species is especially difficult. Most of the information that nematologists use when characterizing and identifying specimens is based on morphological and morphometrical characters. Although these characters are of primary importance, in the last three decades they have been supplemented by biochemical/ molecular characters. Biochemical approaches include the separation of proteins (general proteins and isozymes) by one-dimensional gel electrophoresis, isoelectric focusing, two-dimensional gel electrophoresis, and sodium dodecyl sulphate-capillary gel electrophoresis. Serology has also been found effective in the identification and quantification of nematodes, monoclonal antibodies being a more useful immunological tool than polyclonal antibodies. Identification based on the direct examination of DNA is potentially a more powerful method to characterize inter- and intra-specific variability. The development of techniques such as the polymerase chain reaction, restriction fragment length polymorphism, randomly amplified polymorphic DNA, and amplified fragment length polymorphism has increased the accuracy and speed of nematode characterization/identification. Progress continues to be made and more and more nematologists are using molecular techniques for diagnostic purposes and to assess genetic variation

Human toxocariasis: contribution by Brazilian researchers

In the present paper the main aspects of the natural history of human infection by Toxocara larvae that occasionally result in the occurrence of visceral and/or ocular larva migrans syndrome were reviewed. The contribution by Brazilian researchers was emphasized, especially the staff of the Tropical Medicine Institute of São Paulo (IMT)