Distribuição quantitativa dos casos de dengue no Paraná entre 2012 e 2016 / Quantitative distribution of dengue cases in the state of Paraná between 2012-2016

Introdução: A dengue é uma das principais arboviroses no mundo e no Brasil é responsável por milhares de casos anualmente. No Paraná, a doença tornou-se endêmica a partir da última década. Objetivo: O trabalho quantificou os casos de dengue no Paraná entre 2012 e 2016, analisando distribuição, formas graves e número de óbitos. Métodos: A pesquisa usou dados obtidos pelo SINAN e agrupou conforme período e região de ocorrência. Resultados: O total de casos variou de 18.824 (2013-2014) a 56.351 (2015-2016). Os registros de dengue com sinais de alarme (DSA) e dengue grave (DG) passaram de 195 e 32 para 780 e 132, respectivamente. O número de óbitos variou de 9 a 61. Conclusão: Nas regiões Norte, Noroeste e Oeste o número de casos foi elevado durante todo o período estudado, já no Leste, Campos Gerais e Centro-Sul a transmissão se iniciou mais tardiamente (AU).

INTRODUCTION Dengue is one of the leading arboviroses in the world, and in Brazil it accounts for thousands of cases annually. In the state of Paraná, the disease has become endemic since the last decade. OBJECTIVE The study quantified the cases of dengue in Paraná between 2012 and 2016, analyzing the distribution, severe forms, and number of deaths. METHODS The survey used data obtained by SINAN, and grouped them according to the period and region of occurrence. RESULTS: The total number of cases varied from 18,824 (2013-2014) to 56,351 (2015-2016). Records of dengue with alarming signals (DAS) and severe dengue (SD) increased from 195 and 32 to 780 and 132, respectively. The number of deaths varied from 9 to 61. CONCLUSION In the North, Northwest and West regions, the number of cases was high throughout the study period. In the East, Campos Gerais and Central-South regions, the transmission started later (AU).

Bacillus thuringiensis: mechanism of action, resistance, and new applications: a review.

Since the first report by Ishiwata in 1902 of a Bombyx mori infection, followed by the description by Berliner, Bacillus thuringiensis (Bt) has become the main microorganism used in biological control. The application of Bt to combat invertebrates of human interest gained momentum with the growing demand for food free of chemical pesticides and with the implementation of agriculture methods that were less damaging to the environment. However, the mechanisms of action of these products have not been fully elucidated. There are two proposed models: the first is that Bt causes an osmotic imbalance in response to the formation of pores in a cell membrane, and the second is that it causes an opening of ion channels that activate the process of cell death. There are various ways in which Bt resistance can develop: changes in the receptors that do not recognize the Cry toxin, the synthesis of membrane transporters that eliminate the peptides from the cytosol and the development of regulatory mechanisms that disrupt the production of toxin receptors. Besides the potential for formulation of biopesticides and the use in developing genetically modified cultivars, recent studies with Bt have discussed promising applications in other branches of science. Chitinase, an enzyme that degrades chitin, increases the efficiency of Bt insecticides, and there has been of increasing interest in the industry, given that its substrate is extremely abundant in nature. Another promising field is the potential for Bt proteins to act against cancer cells. Parasporins, toxins of Bt that do not have an entomopathogenic effect, have a cytotoxic effect on the cells changed by some cancers. This demonstrates the potential of the microorganism and new opportunities opening for future applications.

Development of a Low Cost Bioprocess for Endotoxin Production by Bacillus thuringiensis var israelensis Intended for Biological Control of Aedes aegypti

Aedes aegypti is the vector of Dengue disease, responsible for 20,000 deaths/year worldwide. Bacillus thuringiensis var israelensis - Bti releases selective and effective toxins (crystal proteins) against A. aegypti larvae. We present a low cost bioprocess for toxin production, accomplished by a selected Brazilian strain Bti (BR-LPB01) and employment of low cost substrates. Soybean meal and sugarcane molasses lead to high toxic effectiveness after 2L bioreactor fermentation (LD50=26ng/mL), near to the reference strain IPS82 (LD50=17.3 ng/mL). The pH ranged between 5.8 and 7.0 during the exponential growth period and between 7.0 and 8.4 during the stationary phase, with low activity. Thus, control of foam and pH 7.0 were started and proved to be crucial for high activity. It was verified that the fermentation could be discontinued after 20 hours, when the highest activity was present.

A dengue é transmitida pelo Aedes aegypti, doença responsável por 20.000 mortes/ano no mundo. Bacillus thuringiensis var israelensis libera toxinas seletivas e eficazes (proteínas cristal) contra larvas de A. aegypti. Propõe-se um bioprocesso de baixo custo para a produção da toxina, pelo emprego de uma cepa brasileira selecionada de Bti (BR-LPB01) e de substratos de baixo custo. Farelo de soja e melaço de cana levaram a eficácia tóxica alta após fermentação em biorreator 2L (DL50=26ng/mL), valor próximo a estirpe de referência IPS82 (DL50=17,3 ng/mL). O pH variou entre 5,8 e 7,0 durante o período de crescimento exponencial e entre 7,0 e 8,4 durante a fase estacionária, com baixa atividade larvicida. Assim, controles de espuma e de pH 7,0 foram iniciados e demonstraram serem cruciais para alta atividade. Verificou-se que a fermentação deve ser interrompida após vinte horas, quando se obtém a maior atividade.