Ultrastructural and pathogenicity of Brevibacillus laterosporus against sinantropic muscoid dipterans.

Brevibacillus laterosporus has entomopathogenic potential against several orders of insects and its wide bioactivity is associated with a variety of strain-specific molecules. In order to avoid the use of synthetic insecticides, along with the need to control insect pests, microbial control has been widely used. Muscoid dipterans are known for their medical-veterinary and sanitary importance, and synanthropy. The enormous biotechnological potential of B. laterosporus has been demonstrated, but there are still few studies with muscoid dipterans. The aim of the study was to verify the mortality of B. laterosporus NRS590 on synanthropic flies and to characterize its different cell stages ultrastructurally. The flies were collected from garbage bins and the colonies were adapted to the laboratory conditions. Bioassays with neo larvae were carried out from the bacterial growth in the phases: vegetative (6 hr), sporangium (20 hr), and free spores (44 hr). An aliquot of each phase was collected for Transmission (TEM) and Scanning Electron Microscopy (SEM). The effectiveness of NRS590 was observed in the sporulation phase, where the corrected mortality was 83.3, 85.1, and 99% for Chrysomya megacephala, Chrysomya putoria, and Musca domestica, respectively. The parasporal body was observed in detail on the entire spore surface. Although our knowledge of this bacterium is growing, it remains to be determined the real virulence factors responsible for the wide entomopathogenic activity observed on muscoid dipterans. Therefore, this study can provide subsidies for the improvement of efficient and safe microbial control techniques for the environment and living beings.

Clinical, electroneuromyographic and morphological studies of pure neural leprosy in a Brazilian referral centre.

Nineteen patients with pure neural leprosy were analysed with clinical examination, electroneuromyography and histopathology of nerve biopsies. Clinical examination showed sensory loss (78.9%), paresis (78.9%), nerve enlargement (68.4%) and nerve pain (42.1%). Electroneuromyographic study revealed an axonal pattern in 18 patients (94.7%) and a demyelinating pattern in one (0.5%). Mononeuropathy multiplex was the most frequent presentation (78.9%), followed by mononeuropathy simplex (10.5%) and polyneuropathy (10.5%). The histopathological study showed the presence of inflammatory infiltrate composed of epithelioid granuloma (42.1%), mononuclear infiltrate (36.8%) or macrophages positive for bacilli (21%). Fibrosis was present in 78.9% of the biopsies. Examination of semithin sections revealed, besides inflammatory infiltrate, myelinated fibre loss (94.7%), remyelination (42%), axonal degeneration (10%) as well as regeneration (31.5%). Based on these results, the pathogenesis of leprosy neuropathy in this group of patients is briefly discussed.

Estudo da interação de Leishmania amazonensis com fibroblastos de cultura primária de músculo esquelético e cardíaco de camundongos / Study of the interaction of Leishmania amazonensis in fibroblasts primary culture of skeletal and cardiac muscle of mice

Culturas primárias de fibroblastos foram obtidas a partir da dissociação de tecidos de músculo esquelético e cardíaco de embriões de camundongos suiços. Após 48h de cultivo a 37C e 5% CO2 formavam-se monocamadas que foram utilizadas para diferentes experimentos...Culturas de fibroblastos obtido de músculo cardíaco de embriões de camundongos irradiadas com raios gama foram infectadas com formas promastigotas de L. Amazonensis e tratadas com L-leu-Ome no quarto dia de infecção. este dia foi selecionado por apresentar os índices mais altos de infecção. Na concentração de 1nM nos tempos de 1, 2 e 24 horas os fibroblastos apresentaram parasitas destruídos, com percentuais de inibição da infecção de 16,63%, 10,68% e 84,36%, respectivamente. Na concentração de 2mM e nos mesmos tempos estes índices foram 13,78%, 25,71% e 95,9%. Nas culturas controle, os índices médios de infecção de 27,35% +- 7,56 (1 hora), 17,50 +- 4,09 (2 horas) e de 26,85 + - 8,27 (24 horas), confirmando os dados referentes à infecção de fibroblastos de músculo esquelético pelo mesmo parasita