Estimação de parâmetros genéticos para resistência à infecção por IMNV em camarões Litopenaeus vannamei por meio de análise de sobrevivência

The main specie of marine shrimp raised at Brazil and in the world is Litopenaeus vannamei, which had arrived in Brazil in the `80s. However, the entry of infectious myonecrosis virus (IMNV), causing the infectious myonecrosis disease in marine shrimps, brought economic losses to the national shrimp farming, with up to 70% of mortality in the shrimp production. In this way, the objective was to evaluate the survival of shrimps Litopenaeus vannamei infected with IMNV using the non parametric estimator of Kaplan-Meier and a model of frailty for grouped data. It were conducted three tests of viral challenges lasting 20 days each, at different periods of the year, keeping the parameters of pH, temperature, oxygen and ammonia monitored daily. It was evaluated 60 full-sib families of L. vannamei infected by IMNV in each viral challenge. The confirmation of the infection by IMNV was performed using the technique of PCR in real time through Sybr Green dye. Using the Kaplan-Meier estimator it was possible to detect significant differences (p <0.0001) between the survival curves of families and tanks and also in the joint analysis between viral challenges. It were estimated in each challenge, genetic parameters such as genetic value of family, it`s respective rate risk (frailty), and heritability in the logarithmic scale through the frailty model for grouped data. The heritability estimates were respectively 0.59; 0.36; and 0.59 in the viral challenges 1; 2; and 3, and it was also possible to identify families that have lower and higher rates of risk for the disease. These results can be used for selecting families more resistant to the IMNV infection and to include characteristic of disease resistance in L. vannamei into the genetic improvement programs

Prevalência e fatores associados à testagem para HIV em homens que fazem sexo com homens

A infecção por HIV/Aids (vírus da imunodeficiência humana/síndrome da imunodeficiência adquirida) constitui um importante problema mundial de Saúde Pública. Dados do último boletim apresentado pela UNAIDS (Organização das Nações Unidas para Aids) em 2013, apontam que mais de 35 milhões de pessoas vivem com HIV em todo mundo. No Brasil, a epidemia é concentrada, com prevalência de infecção menor que 1% na população de 15 a 49 anos, porém chegando a 10,5% entre homens que fazem sexo com homens (HSH). O diagnóstico precoce do HIV se associa a uma redução da morbidade, mortalidade e também da transmissão desta infecção. O presente estudo tem o objetivo de avaliar a prevalência e fatores associados à testagem prévia para HIV na população de HSH dos municípios de Natal/RN e Parnamirim/RN. Os participantes respondiam a um questionário contendo perguntas referentes a dados sociodemográficos, padrões de relacionamento sexual, conhecimentos sobre HIV/Aids, uso de preservativo, consumo de álcool, drogas e busca de testagem para HIV e sífilis. Em seguida, os que desejassem poderiam realizar teste rápido para HIV e sífilis. No total, foram pesquisados 101 sujeitos, destes, 70 foram recrutados com a utilização da técnica Respondent Driving Sample, e 31 com uma amostra de conveniência. O teste de HIV havia sido realizado por 63,3% dos homens pelo menos uma vez na vida. A testagem prévia para HIV foi associada à idade (27 anos ou mais), realização prévia do teste para sífilis, conhecimento sobre locais onde o teste de HIV é feito gratuitamente e resultado positivo para sífilis no momento da pesquisa. A prevalência de testagem para HIV na amostra foi baixa, semelhante ao verificado em outros estudos com a população HSH. Ações que priorizem a divulgação de locais onde o anti-HIV pode ser realizado gratuitamente e direcionadas para o público jovem parecem ser as mais adequadas para a ampliação da testagem entre os HSH na nossa realidade

Estratégias de Produção in vitro de Bioinseticida Viral: influências do Isolado, da Cinética e do Modo de operação

Societal concerns about environmental sustainability has lead to the development of ecologically-friendly alternatives to chemical insecticides for crop protection. One such alternative is biological pest control. In particular, baculoviruses are well suited as insect biopesticides due to their narrow host specificity and relative ease of propagation. In Brazil, the baculovirus Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV) is the main biological control agent employed for the soybean pest, Anticarsia gemmatalis. This baculovirus biopesticide is currently produced using caterpillars, but increasing market demand for the product has encouraged the development of an in vitro manufacturing process, which can be scaled up to much higher virus productivities. In this study, three wild-type AgMNPV isolates (AgMNPV-2D, AgMNPV-MP2 and AgMNPV-MP5) and a recombinant form (vAgEGT-LacZ) were characterised in terms of occlusion body (OB) production and infection kinetics, to enable future optimisation of the in vitro production process. These viruses were propagated using a Spodoptera frugiperda (IPLB-SF21) insect cell line grown in shaker-flask batch cultures. Among the virus isolates tested, AgMNPV-MP5 was found to be the best producer, yielding (5.3±0.85)x108 OB/mL after 8 days post infection. The characterisation of vAgEGT-LacZ propagation in suspension cell cultures has not been previously reported in the literature; hence it became the main focus for this thesis. In particular, it was carried out a study on the effect of the multiplicity of infection (MOI) on OB production. Five successive batches were performed getting a final production (8.9±1.42)x1014 occlusion bodies, considering that production is related for a bioreactor with final volume of 10m3. A low MOI associated with a fed-batch process for vAgEGT-LacZ production was found to support a 3-fold higher OB yield when compared to the default batch process (1.8x107 and 5.3x107 OB/mL, respectively). This yield is competitive with regards to the production process.