Entomopathogenic Viruses in the Neotropics: Current Status and Recently Discovered Species.

The market for biological control of insect pests in the world and in Brazil has grown in recent years due to the unwanted ecological and human health impacts of chemical insecticides. Therefore, research on biological control agents for pest management has also increased. For instance, insect viruses have been used to protect crops and forests around the world for decades. Among insect viruses, the baculoviruses are the most studied and used viral biocontrol agent. More than 700 species of insects have been found to be naturally infected by baculoviruses, with 90% isolated from lepidopteran insects. In this review, some basic aspects of baculovirus infection in vivo and in vitro infection, gene content, viral replication will be discussed. Furthermore, we provide examples of the use of insect viruses for biological pest control and recently characterized baculoviruses in Brazil.

The Fitness and Economic Benefits of Rearing the Parasitoid Telenomus podisi Under Fluctuating Temperature Regime.

Successful biological control requires detailed knowledge about the mass rearing conditions of the control agents in order to ensure higher quality of field-released insects. Thus, we investigated whether rearing fluctuating thermal condition would affect the fitness and costs of the parasitoid wasp Telenomus podisi Ashmead (a biocontrol agent used for controlling the Neotropical brown stink bug Euschistus heros (Fabricius)) when compared with parasitoid reared at constant temperature condition, which is commonly used in insect facilities. Parasitoids were reared under either constant (continuous exposure at 25 ± 2°C) or fluctuating temperature conditions (i.e., 30 ± 2°C during day and 20 ± 2°C at night) during four consecutive generations. Our results indicated that tested fluctuating temperature is more suitable for rearing of T. podisi as such temperature condition not only resulted in fitness benefits (e.g., shorter developmental time, longer female longevity, higher fecundity/fertility) but also reduced (approximately 23.5%) the estimated costs for producing the parasitoids. Furthermore, rearing T. podisi under fluctuating temperatures improved tolerance to low constant temperatures (i.e., 20°C) without changing the tolerance to constant high temperatures (30°C) in the fourth generation. Surprisingly, even parasitoids that developed under fluctuating thermal conditions performed better than those reared at constant temperature of 25°C. Collectively, our findings suggest that T. podisi reared under fluctuating thermal condition can tolerate better fluctuating temperatures that normally occur both during long periods of transport and in agricultural ecosystems, which will increase the quality and productivity of mass-reared T. podisi for inundative releases.

Life History Traits and Predatory Performance of Belostoma anurum (Hemiptera: Belostomatidae), a Biological Control Agent of Disease Vector Mosquitoes.

Understanding the life cycle and dietary requirements of laboratory-reared insects is critical for optimizing resources (including time) and can provide more reliable ecological basis for using such biological control agents in realistic programs. Here, we evaluated the complete development and the predatory abilities of Belostoma anurum (Herrich-Schäffer, 1848) (Hemiptera: Belostomatidae), an aquatic predator widely distributed in Neotropical region, when reared at different diets. We firstly investigated the predatory performance of B. anurum nymphs upon mosquito larvae (i.e., larvae of Aedes aegypti (Linnaeus, 1758) or Culex sp. (Diptera: Culicidae)) and, second, whether the immature diets (i.e., arthropod-based diet (mosquito larvae and adults of Notonectidae) or vertebrate (fish larvae)-based diet) affect the predatory behavior of B. anurum adults. The B. anurum egg-to-adult developmental time was 85.1 days in an arthropod-based diet. However, when a fish-based diet was offered after nymphs reached 3rd instar, we recorded up to 50% reductions on the B. anurum developmental time. Interestingly, B. anurum adults could live more than 1 year under laboratory conditions, independently of the immature diet regime. Furthermore, the fish diet-experienced B. anurum adults spent less time feeding on fish larvae when compared with adults that never experienced this type of diet. Predatory results revealed that 2nd instar B. anurum were more efficient to catch and consume larvae of A. aegypti than of Culex sp. Collectively, our findings show that B. anurum is long-lived aquatic predators, and demonstrate the impacts of dietary regime on the life history traits and predatory performance of these insects.

Extremely Low Frequency Electromagnetic Fields impair the Cognitive and Motor Abilities of Honey Bees.

Extremely low frequency electromagnetic field (ELF EMF) pollution from overhead powerlines is known to cause biological effects across many phyla, but these effects are poorly understood. Honey bees are important pollinators across the globe and due to their foraging flights are exposed to relatively high levels of ELF EMF in proximity to powerlines. Here we ask how acute exposure to 50 Hz ELF EMFs at levels ranging from 20-100 µT, found at ground level below powerline conductors, to 1000-7000 µT, found within 1 m of the conductors, affects honey bee olfactory learning, flight, foraging activity and feeding. ELF EMF exposure was found to reduce learning, alter flight dynamics, reduce the success of foraging flights towards food sources, and feeding. The results suggest that 50 Hz ELF EMFs emitted from powerlines may represent a prominent environmental stressor for honey bees, with the potential to impact on their cognitive and motor abilities, which could in turn reduce their ability to pollinate crops.

Enhanced expression of PD-L1 and IFN-γ on dendritic cells is associated with BCG-induced Th2 inhibition.

Accumulating evidence indicates that the exposure to Mycobacterium bovis bacillus Calmette-Guérin (BCG) prevents the development of allergy and the airway dendritic cells (DCs) may be involved in this protective effect. However, studies to better characterize the specific interactions between BCG and DCs and their role in this mycobacteria-mediated Th2 cell suppression are still ongoing. This study aimed to evaluate the effect of the neonatal BCG vaccination in the innate immune response in a mouse model of ovalbumin (OVA)-induced airway inflammation. BCG treated neonatal BALB/c mice were sensitized and challenged with aerosolized OVA. Twenty-four hours after the last challenge, samples were collected for analysis. The intranasal BCG treatment inhibited the allergic Th2-response by decreasing the allergen-induced eosinophilic inflammation, EPO activity, CCL11, IL-25, TSLP, IL-4 and IL-5 lung levels, and serum levels of IgE. Mycobacteria treatment increased lung levels of IL-10 and TGF-ß, and the TLR2 and TLR4 expressions by pulmonary CD11c+CD103+CD8α+ DCs. Additionally an enhanced expression of PD-L1 was observed besides an increased production of IFN-γ by these cells. These results indicated that neonatal BCG vaccination inhibits key features of allergic airway inflammation, probably by promoting T regulatory immune response via an enhanced expression of TLR2, TLR4 and PD-L1 on DCs.

Drosophila suzukii in Southern Neotropical Region: Current Status and Future Perspectives.

Non-native insect pests are often responsible for important damage to native and agricultural plant hosts. Since Drosophila suzukii Matsumura (Diptera: Drosophilidae) has become an important pest in North America and Europe (i.e., in 2008), the global production of soft thin-skinned fruits has faced severe production losses. In the southern Neotropical region, however, the first record of D. suzukii occurred in 2013 in the south of Brazil. It has also been recorded in Uruguay, Argentina, and Chile. Despite its recent occurrence in the southern Neotropical region, the fast dispersion of D. suzukii has inspired local research efforts in an attempt to mitigate the consequences of this insect pest invasion. In this forum, we explore the current status of D. suzukii in southern Neotropical regions, discussing its future perspectives. Additionally, we attempt to draft activities and a research agenda that may help to mitigate the losses caused by D. suzukii in native and commercial soft-skinned fruits produced in this region. Currently, D. suzukii appears to be well established in the south of Brazil, but considering the entire southern Neotropical region, the invasion panorama is still underinvestigated. The lack of studies and regulatory actions against D. suzukii has contributed to the invasion success of this species in this region. Considering several peculiarities of both the pest biology and the environmental of this region, the authors advocate for the need of intensive and integrative studies toward the development and implementation of area-wide integrated pest management programs against D. suzukii in the southern Neotropical region.

Obesity promotes prolonged ovalbumin-induced airway inflammation modulating T helper type 1 (Th1), Th2 and Th17 immune responses in BALB/c mice.

Clinical and epidemiological studies indicate that obesity affects the development and phenotype of asthma by inducing inflammatory mechanisms in addition to eosinophilic inflammation. The aim of this study was to assess the effect of obesity on allergic airway inflammation and T helper type 2 (Th2) immune responses using an experimental model of asthma in BALB/c mice. Mice fed a high-fat diet (HFD) for 10 weeks were sensitized and challenged with ovalbumin (OVA), and analyses were performed at 24 and 48 h after the last OVA challenge. Obesity induced an increase of inducible nitric oxide synthase (iNOS)-expressing macrophages and neutrophils which peaked at 48 h after the last OVA challenge, and was associated with higher levels of interleukin (IL)-4, IL-9, IL-17A, leptin and interferon (IFN)-γ in the lungs. Higher goblet cell hyperplasia was associated with elevated mast cell influx into the lungs and trachea in the obese allergic mice. In contrast, early eosinophil influx and lower levels of IL-25, thymic stromal lymphopoietin (TSLP), CCL11 and OVA-specific immunoglobulin (IgE) were observed in the obese allergic mice in comparison to non-obese allergic mice. Moreover, obese mice showed higher numbers of mast cells regardless of OVA challenge. These results indicate that obesity affects allergic airway inflammation through mechanisms involving mast cell influx and the release of TSLP and IL-25, which favoured a delayed immune response with an exacerbated Th1, Th2 and Th17 profile. In this scenario, an intense mixed inflammatory granulocyte influx, classically activated macrophage accumulation and intense mucus production may contribute to a refractory therapeutic response and exacerbate asthma severity.

Serum levels of nitric oxide and cytokines in smokers at the beginning and after 4months of treatment for smoking cessation.

INTRODUCTION: Nitric oxide (NO) modulates inflammatory reactions, having beneficial or toxic effects depending on the concentration. Its elevation can cause proinflammatory effects amplifying the inflammatory process with the participation of cytokines. Smoking has a negative impact on health and is considered one of the risk factors that influence disease development facilitating inflammatory processes. AIM: To compare the serum concentration of NO and cytokines in smokers at baseline and after 4months of abstinence treatment. METHODS: Blood samples which were collected to obtain the serum, at baseline and after 4months, were stored at -80°C until analysis. NO was measured by the total dose of nitrite determined by the Greiss method. CBA was the used technique to determine the concentration of cytokines in supernatants serum. The initial and final results of NO, TNF-α, IL-1, IL-6, IL-8, IL-10 and IL-12 that remained after 4months treatment were compared. Wilcoxon test was used to compare the data and Spearman test for correlations between NO and other variables. A significance level of p<0.05 was adopted. RESULTS: The analysis of NO observed a significant reduction (p=0.001) of the initial median value of 18.80 (3.55-80.01) µmol/L to 8.10 (2.85-14.97) µmol/L after 4months of treatment. There were no significant differences in cytokines from baseline to the end of treatment. CONCLUSION: The results may not mean harm to the body, but an adaptive process, decreasing the metabolism of abstinents due to the reduction of the use of nicotine.

Agrochemical-induced stress in stingless bees: peculiarities, underlying basis, and challenges.

The toxicological stress induced by pesticides, particularly neonicotinoid insecticides, and its consequences in bees has been the focus of much recent attention, particularly for honey bees. However, the emphasis on honey bees and neonicotinoids has led to neglect of the relevance of stingless bees, the prevailing pollinators of natural and agricultural tropical ecosystems, and of other agrochemicals, including other pesticides and even leaf fertilizers. Consequently, studies focusing on agrochemical effects on stingless bees are sparse, usually limited to histopathological studies, and lack a holistic assessment of the effects of these compounds on physiology and behavior. Such effects have consequences for individual and colony fitness and are likely to affect both the stingless bee populations and the associated community, thereby producing a hierarchy of consequences thus far overlooked. Herein, we review the current literature on stingless bee-agrochemical interactions and discuss the underlying mechanisms involved in reported stress symptoms, as well as the potential consequences based on the peculiarities of these pollinators.

Microemulsão: um promissor carreador para moléculas insolúveis / Microemulsion: a promising carrier system for insoluble compounds

Microemulsão (ME) é um sistema que foi descoberto por Hoar e Schulman no ano de 1943 e que é termodinamicamente estável e isotropicamente translúcido de dois líquidos imiscíveis (óleo/água), estabilizados por um filme interfacial de tensoativos. O estudo de sistemas microemulsionados se baseia nas suas três teorias de formação: (1) teoria da solubilização, (2) teoria da tensão interfacial e (3) teoria termodinâmica. A estrutura formada é influenciada pelas propriedades físico-químicas dos componentes utilizados e da razão entre os componentes. O objetivo desta revisão foi avaliar o estado da arte de sistemas microemulsionados enfatizando uma abordagem teórica. Além disso, os recentes avanços sobre a aplicabilidade clínca e utilização como carreador de moléculas insolúveis foram discutidas.

Microemulsions (ME) are thermodynamically stable and isotropic systems of two immiscible liquids (oil/water), stabilized by an interfacial film of surfactants, discovered by Hoar and Schulman in 1943. The study of ME formation is based on three areas of theory: (1) solubilization, (2) interfacial tension and (3) thermodynamics. ME structures are influenced by the physicochemical properties and proportions of their ingredients. The goal of this review is to assess the state of the art of microemulsified systems, from a theoretical viewpoint. Also, recent progress on their clinical application and use as carriers for insoluble compounds is discussed.

[Killer toxin and enzyme production by Candida albicans isolated from buccal mucosa in patients with cancer]. / Toxinas killer e produção de enzimas por Candida albicans isoladas da mucosa bucal de pacientes com câncer.

Opportunistic infections of the oral cavity are primarily caused by Candida and frequently occur in patients with cancer who are undergoing chemotherapy and antibiotic treatment. Of the specimens received from the oral mucosa of 44 patients with cancer, 25 (56.8%) yielded Candida on culture in Sabouraud agar. Twenty four of these isolates were identified as C. albicans (96%) and 1 as C. krusei (4%). The phenotypic characteristics of these isolates showed that all of them were strongly proteolytic, had a high ability to produce phospholipase, and presented the byotypes characterized as 811 (95.8%) and 511 (4.2%) in terms of susceptibility to killer toxins.

Toxinas killer e produção de enzimas por Candida albicans isoladas da mucosa bucal de pacientes com câncer / Killer toxin and enzyme production by Candida albicans isolated from buccal mucosa in patients with cancer

Opportunistic infections of the oral cavity are primarily caused by Candida and frequently occur in patients with cancer who are undergoing chemotherapy and antibiotic treatment. Of the specimens received from the oral mucosa of 44 patients with cancer, 25 (56.8%) yielded Candida on culture in Sabouraud agar. Twenty four of these isolates were identified as C. albicans (96%) and 1 as C. krusei (4%). The phenotypic characteristics of these isolates showed that all of them were strongly proteolytic, had a high ability to produce phospholipase, and presented the byotypes characterized as 811 (95.8%) and 511 (4.2%) in terms of susceptibility to killer toxins.

Infecções oportunistas da cavidade bucal são primariamente causadas por fungos do gênero Candida e freqüentemente ocorrem em pacientes com câncer que estão sobtratamento quimioterápico e antibacteriano. De 44 amostras coletadas da mucosa oral de pacientes com câncer, observou-se o isolamento de 25 leveduras do gênero Candida em cultivo realizado em ágar Sabouraud-dextrose. Foram identificados Candida albicans em 24 (96%) isolados e C. krusei em 1 (4%). As características fenotípicas das amostras de Candida albicans mostraram que todos os isolados foram fortemente proteolíticos, capazes de produzir fosfolipases e possuíam os biotipos caracterizados como 811(95,8%) e 511 (4,2%) em relação a susceptibilidade às toxinas killer.

A processing enzyme for prodynorphin derived peptides.

Endo-oligopeptidase A known to hydrolyse the Phe5-Ser6 bond of bradykinin and the Arg8-Arg9 bond of neurotensin has been shown to produce, by a single cleavage, leucine5-enkephalin from small prodynorphin derived enkephalin-containing peptides. The specificity constants (kcat/km) obtained for the hydrolysis of bradykinin, neurotensin and dynorphin B are of the same order, suggesting that the substrate amino acid sequence is not the only factor determining the cleavage site of this enzyme.