To evaluate the toxic effect of commercial formulations of neem oil, Azadirachta indica A. Juss, pre-pupae (PP), young pupae (YP) and old pupae (OP) of Diatraea saccharalis F. (Lepidoptera: Crambidae) were sprayed with the diluted extract in distilled water at concentrations of 0.0, 0.3, 0.5, 1.0 and 2.0%. The neem extract caused concentration-dependent effects on mortality of pupae, and the pupae that failed to emerge in adults had multiple abnormalities. The longevity of pupae that emerged in adults (YP and OP group) did not differ from the control group. The abnormalities found in adults were related to mortality in all treatments, except at the concentration of 1.0%. Fertility was assessed according to the oviposition of adult females from the YP group that showed no abnormalities, through the evaluation of the number of deposited eggs and the rate of undeveloped eggs. The results showed a reduction in the number of eggs laid and an increase in the percentage of undeveloped eggs. These results show that neem oil has a high potential to control the toughest stage of the sugarcane borer and also reduces the further development. Therefore, commercial formulations of neem oil have a toxic effect on pupae and adults of D. saccharalis.

No abstract

The acute T. gondii infection in the ileum of rats changes the proportion of VIPergic neurons and the epithelial cells, which can compromise the mucosal defense during infection.

The strains MT and E9 of Metarhizium anisopliae were found to be effective in causing the morphological changes in pupae of Diatraea saccharalis of different ages. However, during the treatment with the two strains, it was observed that there was a decrease in the longevity of old pupae and adults that emerged from old and young pupae. The adults that emerged died 24 h later and were totally covered by the pathogen's mycelium. Regarding the mortality of pupae of different ages, but in relation to the abnormalities, the pre-pupae were found to be more susceptible. The morphological alterations observed in the cuticle and in the internal tissues of the pupae were analyzed using a stereomicroscope, a light microscope and a scanning electron microscope. The adhesion stage and formation of the appressorium happened 18 h after the infection, occasioning black spots and depressions in the cuticle of young and old pupae. In pre-pupae, the sclerotization was not observed and the fungus acted faster and more effectively, thereby, achieving 100% mortality. The colonization of the pathogen was observed in young pupae between 48 and 120 h. The alterations were observed in the fat body, digestive system and musculature; moreover, several vacuoles were noticed inside the pupae. The extrusion happened after 120 h, presenting the mycelial growth upon the pupae cuticle and further sporulation upon the corpses. The morphological alterations that took place during the development of M. anisopliae suggest the possible causes for the mortality of the pupae of D. saccharalis.

Background Toxoplasma gondii infection can occur through the ingestion of raw meat that contains tissue cysts or food that contains oocysts. Through the ingestion of oocysts, the parasite crosses the intestinal barrier, where the enteric nervous system is located. The objective was to investigate the kinetics of neuronal and glial responses during acute T. gondii infection. Methods We used 45 Wistar rats that were divided into a control group and infected groups that were evaluated at 6, 12, 24, 48, 72 hours, 7 days, 10 days, and 15 days after infection. The rats received 5000 sporulated oocysts of the parasite orally. To detect neurons and enteric glia cells, the myenteric and submucosal plexuses of the duodenum underwent double‐labeling immunohistochemical techniques to evaluate HuC/HuD and S100, HuC/HuD and ChAT, and HuC/HuD and nNOS. Key Results We observed a reduction of the total neuron population in the submucosal plexus 72 hours after infection. Cholinergic neurons decreased in the submucosal plexus 15 days after infection, and nitrergic neurons decreased in the myenteric plexus 72 hours after infection. A decrease in the number of glial cells was observed 7 days after infection in the submucosal plexus, and an increase in the enteric glial cell (EGC)/neuron ratio was found in both plexuses 48 hours after infection. Conclusions and Inferences We found decrease of neurons and increase in the EGC/neuron ratio in both plexuses caused by acute T. gondii infection, with major alterations 72 hours after oral infection. The number of cholinergic neurons decreased in the submucosal plexus, and the number of nitrergic neurons decreased in the myenteric plexus. A decrease in the number of enteric glial cells was observed in the submucosal plexus, and an increase in the enteric glial cell/neuron ratio was observed in both ganglionate plexuses of the duodenum.

No abstract

Studies have reported the resurgence of insect pests that are resistant to chemical and, more recently, to biological pesticides. Diatraea saccharalis is one of the main pests in sugarcane crops and responsible for large losses in the sugar and alcohol industries. The use of plant extracts including garlic essential oil (Allium sativum) which contains allicin, a compound that interferes with biochemical and physiological factors of target insects is considered an efficient and sustainable alternative for integrated pest management. The objective of this study was to test the toxicity of garlic essential oil on D. saccharalis eggs by analyzing rates of unhatched eggs, changes in external morphology, and esterases profile, enzymes related to insect resistance. For this, 24, 48, and 72-h-old eggs were immersed in 0.1, 0.5, and 1% garlic essential oil solutions for 2 min. Observations on embryonic development were made every 24-h for 72-h. Data on unhatched eggs were collected 288-h after treatments. For the esterases profile, eggs at 24-h after treatment with 1% solution were used. Eggs at 24-h-old, showed the least resistance to bioinsecticide, being that, 24-h after treatments with solutions 0.1, 0.5, and 1%, unhatched rates 80, 91.7, and 89.2%, respectively. The absence of embryos, ruptures, and protrusions on the chorionic region, and partial inhibition of EST-9, 10, and 11 were observed 24-h after the bioassays. These results demonstrate that garlic essential oil affects D. saccharalis eggs, partially inhibiting enzymes related to the insect immune system and can be used as a sustainable alternative for the integrated management of this insect pest.

Resumo A microbiota humana é formada por bilhões de microrganismos que atuam beneficiando a saúde do hospedeiro humano contra invasões patogênicas. A mucosa intestinal fica exposta a antígenos que devem ser eliminados pela barreira imunológica, no qual é afetada por fatores como antibióticos, estilo de vida e a dieta do hospedeiro, sendo a dieta, o fator que mais associa-se com a microbiota intestinal. Os probióticos são microrganismos vivos que quando administrados em quantidades adequadas, asseguram benefícios à saúde do hospedeiro. Os prebióticos equilibram a flora intestinal e devem ser associados com uma alimentação saudável. A alimentação da mãe influencia a microbiota do bebê que é imatura, sendo colonizada após o nascimento. Através da alimentação ao longo da vida, novos microrganismos são introduzidos para formar uma microbiota intestinal madura que beneficia a saúde do hospedeiro. As alterações no desenvolvimento da microbiota podem ter efeitos negativos na saúde do hospedeiro, com desequilíbrios que causam doenças. Neste contexto, o presente estudo tem como objetivo relacionar a influência da microbiota intestinal humana com o sistema imunológico na proteção do organismo, associado com a alimentação ao longo da vida. Foi realizada uma pesquisa descritiva de levantamento bibliográfico a partir de publicações científicas nos idiomas de Português e Inglês. Foram consultados livros, dissertações, teses e outras documentações eletrônicas vinculadas às bases de dados como Scielo (Scientific Eletronic Library Online), Pubmed (National Center Biotechnology Information) e Google Acadêmico, com motores de busca através de trabalhos publicados em periódicos a partir do ano 2008 e outras publicações anteriores relevantes. Conclui-se que o sistema imunológico está intimamente ligado com a microbiota intestinal e a dieta é o maior contribuinte das alterações ocorridas. Uma alimentação equilibrada pode elevar a imunidade através da benéfica ação na microbiota intestinal. Palavras-chave: imunidade, dieta, trato gastrointestinal.