Concurrent Helminthic Infection Protects Schoolchildren with Plasmodium vivax from Anemia

Background

Plasmodium vivax is responsible for a significant portion of malaria cases worldwide, especially in Asia and Latin America, where geo-helminthiasis have a high prevalence. Impact of the interaction between vivax malaria and intestinal helminthes has been poorly explored. The objective of this study was to evaluate the influence of intestinal helminthiasis on the concentration of hemoglobin in children with Plasmodium vivax malaria in rural areas in the municipality of Careiro, in the Western Brazilian Amazon.

Methodology/Principal Findings

A cohort study was conducted from April to November 2008, enrolling children from 5 to 14 years old in two rural areas endemic for malaria. A cross-sectional evaluation was performed in April to actively detect cases of malaria and document baseline hemoglobin and nutritional status. Children were followed-up for six months through passive case detection of malaria based on light microscopy. Throughout the follow-up interval, hemoglobin value and stool examination (three samples on alternate days) were performed on children who developed P. vivax malaria. For 54 schoolchildren with a single infection by P. vivax, hemoglobin during the malaria episode was similar to the baseline hemoglobin for children co-infected with Ascaris lumbricoides (n = 18), hookworm (n = 11) and Trichuris trichiura (n = 9). In children without intestinal helminthes, a significant decrease in the hemoglobin during the malarial attack was seen as compared to the baseline concentration. In the survival analysis, no difference was seen in the time (in days) from the baseline cross-sectional to the first malarial infection, between parasitized and non-parasitized children.

Conclusion/Significance

For the first time, a cohort study showed that intestinal helminthes protect against hemoglobin decrease during an acute malarial attack by P. vivax.     

Genes Acquired by Horizontal Transfer Are Potentially Involved in the Evolution of Phytopathogenicity in Moniliophthora perniciosa and Moniliophthora roreri, Two of the Major Pathogens of Cacao

Moniliophthora perniciosa and Moniliophthora roreri are phytopathogenic basidiomycete species that infect cacao causing two important diseases in this crop: “Witches’ Broom” and “Frosty Pod Rot”, respectively. The ability of species from this genus (Moniliophthora) to cause disease is exceptional in the family Marasmiaceae. Species in closely related genera including, Marasmius, Crinipellis, and Chaetocalathus, are mainly saprotrophs and are not known to cause disease. In this study, the possibility that this phytopathogenic lifestyle has been acquired by horizontal gene transfer (HGT) was investigated. A stringent genome comparison pipeline was used to identify potential genes that have been obtained by Moniliophthora through HGT. This search led to the identification of three genes: a metallo-dependent hydrolase (MDH), a mannitol phosphate dehydrogenase (MPDH), and a family of necrosis-inducing proteins (NEPs). Phylogenetic analysis of these genes suggests that Moniliophthora acquired NEPs from oomycetes, MDH from actinobacteria and MPDH from firmicutes. Based on the known gene functions and on previous studies of M. perniciosa infection and development, a correlation between gene acquisition and the evolution of the phytopathogenic genus Moniliophthora can be postulated.     

Effect of diet on male reproductive tract of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae).

The morphology and histology of the reproductive tract of males of the predator Podisus nigrispinus (Dallas) fed on different diets were studied. P. nigrispinus was fed on diets of: larvae of Alabama argillacea (Hübner), Tenebrio molitor L., Musca domestica L., and an artificial diet. The male reproductive tract, independent of diet, showed testes with intense red coloration in a compact, circular, or slightly oval structure. The vasa deferentia were similar in color to the testes and formed long filaments, which joined with the yellow-cream colored ejaculatory duct. The morphological characteristics of the male reproductive tract were similar under all diets, except for the artificial one. The histological studies demonstrated that independent of the diet the testes of P. nigrispinus were composed of four to six follicles. The testes with six follicles generally had four developed and two atrophied follicles. The morphological and histological differences of the testes of P. nigrispinus when fed with different prey are presented and discussed.     

The Role of Reactive Oxygen Species in Anopheles aquasalis Response to Plasmodium vivax Infection

Malaria affects millions of people worldwide and hundreds of thousands of people each year in Brazil. The mosquito Anopheles aquasalis is an important vector of Plasmodium vivax, the main human malaria parasite in the Americas. Reactive oxygen species (ROS) have been shown to have a role in insect innate immune responses as a potent pathogen-killing agent. We investigated the mechanisms of free radicals modulation after A. aquasalis infection with P. vivax. ROS metabolism was evaluated in the vector by studying expression and activity of three key detoxification enzymes, one catalase and two superoxide dismutases (SOD3A and SOD3B). Also, the involvement of free radicals in the mosquito immunity was measured by silencing the catalase gene followed by infection of A. aquasalis with P. vivax. Catalase, SOD3A and SOD3B expression in whole A. aquasalis were at the same levels of controls at 24 h and upregulated 36 h after ingestion of blood containing P. vivax. However, in the insect isolated midgut, the mRNA for these enzymes was not regulated by P. vivax infection, while catalase activity was reduced 24 h after the infectious meal. RNAi-mediated silencing of catalase reduced enzyme activity in the midgut, resulted in increased P. vivax infection and prevalence, and decreased bacterial load in the mosquito midgut. Our findings suggest that the interactions between A. aquasalis and P. vivax do not follow the model of ROS-induced parasite killing. It appears that P. vivax manipulates the mosquito detoxification system in order to allow its own development. This can be an indirect effect of fewer competitive bacteria present in the mosquito midgut caused by the increase of ROS after catalase silencing. These findings provide novel information on unique aspects of the main malaria parasite in the Americas interaction with one of its natural vectors.     

Frog Virus 3 Open Reading Frame 97R Localizes to the Endoplasmic Reticulum and Induces Nuclear Invaginations

Frog virus 3 (FV3) is the type species of the genus Ranavirus, family Iridoviridae. The genome of FV3 is 105,903 bases in length and encodes 97 open reading frames (ORFs). The FV3 ORF 97R contains a B-cell lymphoma 2 (Bcl-2) homology 1 (BH1) domain and has sequence similarity to the myeloid cell leukemia-1 (Mcl-1) protein, suggesting a potential role in apoptosis. To begin to understand the role of 97R, we characterized 97R through immunofluorescence and mutagenesis. Here we demonstrated that 97R localized to the endoplasmic reticulum (ER) at 24 h posttransfection. However, at 35 h posttransfection, 97R localized to the ER but also began to form concentrated pockets continuous with the nuclear membrane. After 48 h posttransfection, 97R was still localized to the ER, but we began to observe the ER and the outer nuclear membrane invaginating into the nucleus. To further explore 97R targeting to the ER, we created a series of C-terminal transmembrane domain deletion mutants. We found that deletion of 29 amino acids from the C terminus of 97R abolished localization to the ER. In contrast, deletion of 12 amino acids from the C terminus of 97R did not affect 97R localization to the ER. In addition, a hybrid protein containing the 97R C-terminal 33 amino acids was similarly targeted to the ER. These data indicate that the C-terminal 33 amino acids of 97R are necessary and sufficient for ER targeting.     

Effect of Chronic Treatment with Conventional and Organic Purple Grape Juices (Vitis labrusca) on Rats Fed with High-Fat Diet

Serra Gaucha is described as the most important wine region of Brazil. Regarding cultivars widespread in the Serra Gaucha, about 90 % of the area is occupied by vines of Vitis labrusca that is the most important specie used in grape juice production. The objective of this study was to investigate the antioxidant and neuroprotective effect of chronic intake of purple grape juice (organic and conventional) from Bordo variety (V. labrusca) on oxidative stress in different brain regions of rats supplemented with high-fat diet (HFD) for 3 months. A total of 40 male rats were randomly divided into 4 groups. Group 1 received a standard diet and water, group 2 HFD and water, group 3 HFD and conventional grape juice (CGJ), and group 4 HFD and organic grape juice (OGJ). All groups had free access to food and drink and after 3 months of treatment the rats were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum isolated and homogenized on ice for oxidative stress analysis. We observed that the consumption of calories in HFD and control groups, were higher than the groups supplemented with HFD and grape juices and that HFD diet group gain more weight than the other animals. Our results also demonstrated that HDF enhanced lipid peroxidation (TBARS) and protein damage (carbonyl) in cerebral cortex and hippocampus, reduced the non-enzymatic antioxidants defenses (sulfhydryl) in cerebral cortex and cerebellum, reduced catalase and superoxide dismutase activities in all brain tissues and enhanced nitric oxide production in all cerebral tissues. CGJ and OGJ were able to ameliorate these oxidative alterations, being OGJ more effective in this protection. Therefore, grape juices could be useful in the treatment of some neurodegenerative diseases associated with oxidative damage.     

Influence of the knee flexion on muscle activation and transmissibility during whole body vibration

The influence of the knee flexion on muscle activation and transmissibility during whole body vibration is controversially discussed in the literature. In this study, 34 individuals had electromyography activity (EMG) of the vastus lateralis and the acceleration assessed while squatting with 60° and 90° of knee flexion either with or without whole-body vibration (WBV). The conditions were maintained for 10 s with 1 min of rest between each condition. The main findings were (1) the larger the angle of knee flexion (90° vs. 60°), the greater the EMG (p < 0.001), with no difference on acceleration transmissibility; (2) for both angles of knee flexion, the addition of WBV produced no significant difference in EMG and higher acceleration compared to without WBV (p < 0.001). These results suggest that the larger the knee flexion angle (60° vs. 90°), the greater the muscle activation without acceleration modification. However, the addition of WBV increases the transmissibility of acceleration in the lower limbs without modification in EMG of vastus lateralis.     

A new subhaplogroup of native American Y-Chromosomes from the Andes

The human Y chromosome contains highly informative markers for making historical inferences about the pre-Columbian peopling of Americas. However, the scarcity of these markers has limited its use in the inference of shared ancestry and past migrations relevant to the origin of the culturally and biologically diverse Native Americans. To identify new single nucleotide polymorphisms (SNPs) and increase the phylogenetic resolution of the major haplogroup Q found in the Americas, we have performed a search for new polymorphisms based on sequencing divergent Y chromosomes identified by microsatellite haplotype analysis. Using this approach, a new Y-SNP (SA01) has been identified in the Andean populations of South America, allowing for the detection of a new sublineage of Q1a3a. This sublineage displays a less complex phylogeographic network of associated microsatellites and more restricted geographic occurrence, and is given the designation Q1a3a4. This result indicates that our approach can be successfully used to identify sublineages of interest in a specific region that allow the investigation of particular histories of human populations.     

Survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus) in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction

This work reports a survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus) in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction (PCR). Seventy pampas deer were captured in the dry season and surveyed using PCR, microscopic agglutination test (MAT) (n = 51) and by both techniques (n = 47). PCR detected infections in two pampas deer and MAT detected infections in three. Through sequencing and phylogenetic analyses, the PCR-amplified fragment detected in deer was identified as Leptospira interrogans. Serovars Pomona and Butembo were detected using MAT and the highest titre was 200 for serovar Pomona. Epidemiological aspects of the findings are discussed.