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The investigation of the glycan repertoire of several organisms has revealed a wide variation in terms of structures and abundance of glycan moieties. Among the parasites, it is possible to observe different sets of glycoconjugates across... more
The investigation of the glycan repertoire of several organisms has revealed a wide variation in terms of structures and abundance of glycan moieties. Among the parasites, it is possible to observe different sets of glycoconjugates across taxa and developmental stages within a species. The presence of distinct glycoconjugates throughout the life cycle of a parasite could relate to the ability of that organism to adapt and survive in different hosts and environments. Carbohydrates on the surface, and in excretory-secretory products of parasites, play essential roles in host–parasite interactions. Carbohydrate portions of complex molecules of parasites stimulate and modulate host immune responses, mainly through interactions with specific receptors on the surface of dendritic cells, leading to the generation of a pattern of response that may benefit parasite survival. Available data reviewed here also show the frequent aspect of parasite immunomodulation of mammalian responses through specific glycan interactions, which ultimately makes these molecules promising in the fields of diagnostics and vaccinology.
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To date, reliable techniques that can provide accurate information on the local and global prevalence of schistosomiasis are still associated with high costs or labour-intensive processes. Here we discuss old and new concepts for... more
To date, reliable techniques that can provide accurate information on the local and global prevalence of schistosomiasis are still associated with high costs or labour-intensive processes. Here we discuss old and new concepts for diagnostic approaches, and we highlight structural properties of schistosome eggshells that result in their affinity for magnetic materials as a new diagnostic approach.
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Research Interests: Microbiology, Biology, Medicine, Experimental parasitology, Humans, and 11 moreFemale, Animals, Liquid Chromatography / Electrospray Ionization Mass Spectrometry, Rats, Wistar Rats, Veterinary Sciences, Two-Dimensional Gel Electrophoresis, Two dimensional Gel Electrophoresis, Proteome, Angiostrongylus cantonensis, and Biomphalaria
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Angiostrongylus cantonensisis the main aetiological agent of eosinophilic meningoencephalitis in humans. Several outbreaks have been documented around the world, cementing its status as an emerging global public health concern. As a... more
Angiostrongylus cantonensisis the main aetiological agent of eosinophilic meningoencephalitis in humans. Several outbreaks have been documented around the world, cementing its status as an emerging global public health concern. As a result, new strategies for the diagnosis, prophylaxis and treatment of cerebral angiostrongyliasis are urgently needed. In this study, we report on thede novoassembly of theA. cantonensistranscriptome, its full functional annotation and a reconstruction of complete metabolic pathways. All results are available at AngiostrongylusDB (http://angiostrongylus.lad.pucrs.br/admin/welcome). The aim of this study was to identify the active genes and metabolic pathways involved in the mechanisms of infection and survival insideRattus norvegicus. Among 389 metabolic mapped pathways, the blood coagulation/antithrombin pathways of heparan sulphate/heparin are highlighted. Moreover, we identified genes codified to GP63 (leishmanolysin), CALR (calreticulin), ACE (pepti...
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Many molluscs may be infected with angiostrongylid larvae. Following the histopathological diagnosis of abdominal angiostrongyliasis in a grape farmer from southern Brazil, molluscs in the area were investigated. During a nocturnal... more
Many molluscs may be infected with angiostrongylid larvae. Following the histopathological diagnosis of abdominal angiostrongyliasis in a grape farmer from southern Brazil, molluscs in the area were investigated. During a nocturnal search, 245 specimens of slugs were collected and identified as the invasive Chinese slug Meghimatium pictum. Angiostrongylus costaricensis worms were recovered from mice that were experimentally infected with larvae obtained from 11 (4.5%) of the molluscs. This study presents the first report of M. pictum being identified as an intermediate host for A. costaricensis. Most of the slugs were collected from grape plants, which suggests that transmission may be associated with grape consumption.
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Angiostrongylus costaricensis is a parasite that infects rodents, including the wild cotton rat Sigmodon hispidus and pygmy rice rats Oligoryzomys spp., among others. However, urban Rattus norvegicus and Mus musculus have not been... more
Angiostrongylus costaricensis is a parasite that infects rodents, including the wild cotton rat Sigmodon hispidus and pygmy rice rats Oligoryzomys spp., among others. However, urban Rattus norvegicus and Mus musculus have not been identified as important hosts of A. costaricensis. In this study, Swiss mice (SW), Wistar R. norvegicus (RN), wild Oligoryzomys nigripes (ON) and a local strain of M. musculus (RGS) were experimentally infected with A. costaricensis. Survival, elimination of L1 (total sum per group, A0), and the number of adult worms recovered divided by the dose of each L3 inoculum (yield ratio, YR) were examined for each group after a 40-day post-infection period. The survival rates, A0 and YR values were: 27%, 207,589 and 0.42 for the SW group; 81%, 8691 and 0.01 for the RN group; and 63.6%, 26,560 and 0.16 for the RGS group, respectively, in each case. The survival rate for the ON group was 100% and the A0 value was 847,050. A YR was not calculated for the ON group sin...
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SUMMARY Baylisascaris procyonis , the raccoon roundworm, infects a wide range of vertebrate animals, including humans, in which it causes a particularly severe type of larva migrans. It is an important cause of severe neurologic disease... more
SUMMARY Baylisascaris procyonis , the raccoon roundworm, infects a wide range of vertebrate animals, including humans, in which it causes a particularly severe type of larva migrans. It is an important cause of severe neurologic disease (neural larva migrans [NLM]) but also causes ocular disease (OLM; diffuse unilateral subacute neuroretinitis [DUSN]), visceral larva migrans (VLM), and covert/asymptomatic infections. B. procyonis is common and widespread in raccoons, and there is increasing recognition of human disease, making a clinical consideration of baylisascariasis important. This review provides an update for this disease, especially its clinical relevance and diagnosis, and summarizes the clinical cases of human NLM and VLM known to date. Most diagnosed patients have been young children less than 2 years of age, although the number of older patients diagnosed in recent years has been increasing. The recent development of recombinant antigen-based serodiagnostic assays has ai...
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Research Interests: Biology, Proteomics, Medicine, Biological Sciences, Phylogeny, and 15 moreSequence alignment, OMEGA, De, Animals, Glutathione, Fasciola hepatica, Detoxification, Tandem Mass Spectrometry, Enzyme, Sigma, Proteome analysis, Glutathione Transferase, Amino Acid Sequence, Molecular Sequence Data, and Medical and Health Sciences
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Angiostrongylus costaricensis is a zoonotic parasitic nematode described for the first time in 1971 by Pedro Morera and Rodolfo Céspedes in Costa Rica. This parasite causes an infection known as abdominal angiostrongyliasis, affecting... more
Angiostrongylus costaricensis is a zoonotic parasitic nematode described for the first time in 1971 by Pedro Morera and Rodolfo Céspedes in Costa Rica. This parasite causes an infection known as abdominal angiostrongyliasis, affecting mainly school-aged children and young adults. Infection with A. costaricensis has been associated with a myriad of rodent and mollusk species in the Americas and the Caribbean, as its natural hosts and reservoirs. In this commemorative review, we highlight the extensive research collected through a 50-year journey, which includes ecological, pathological, and molecular studies on A. costaricensis and its implicated disease. We also identify major knowledge gaps in its evolutionary history, the ecological role of imported and invasive mollusk species, and immune response. We propose that the advent of -omics analyses will allow us to gather novel information regarding A. costaricensis biology and infection dynamics, as well as to promote the design of m...
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INTRODUCTION: Brazil’s southernmost state, Rio Grande do Sul (RGS), was considered schistosomiasis-free until 1998 when a low endemic focus was identified in Esteio, a city located next to the capital of RGS. In the last two decades, the... more
INTRODUCTION: Brazil’s southernmost state, Rio Grande do Sul (RGS), was considered schistosomiasis-free until 1998 when a low endemic focus was identified in Esteio, a city located next to the capital of RGS. In the last two decades, the control interventions applied in the region have been apparently successful, and the absence of new cases indicated the possibility of interrupted schistosomiasis transmission. The objective of this study was to update the clinical and epidemiological data of schistosomiasis in Esteio. METHODS: We reviewed all 28 individuals diagnosed with the infection since 1997 and a survey was applied to a group of 29 school-aged children residing in Vila Pedreira, one of the most affected neighborhoods. RESULTS No eggs were detected in fecal samples using the Helmintex method, and all samples were negative for serum antibodies on examination by the western blot technique using the Schistosoma mansoni microsomal antigen (MAMA- WB). In contrast, 23 individuals (7...
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A infecção parasitária pelo Ascaris lumbricoides representa um acometimento comum no Brasil e em outras regionalidades subdesenvolvidas. A localização do verme em vesícula biliar é rara e quando há presença de quadro clínico importante,... more
A infecção parasitária pelo Ascaris lumbricoides representa um acometimento comum no Brasil e em outras regionalidades subdesenvolvidas. A localização do verme em vesícula biliar é rara e quando há presença de quadro clínico importante, essa hipótese deve ser levantada como diagnóstico diferencial frente a outras doenças da árvore biliar. Relatamos o caso de paciente de 65 anos admitido em emergência devido à pancreatite por etiologia de áscaris em vesícula biliar, o qual, posteriormente, evoluiu para quadro alarmante de disfunção de múltiplos órgãos.
In the present work, we reported for the first time the microbiome from Phyllocaulis soleiformis and Biomphalaria glabrata assessed using high-throughput DNA sequencing pre- and post-infection with the helminth parasite Angiostrongylus... more
In the present work, we reported for the first time the microbiome from Phyllocaulis soleiformis and Biomphalaria glabrata assessed using high-throughput DNA sequencing pre- and post-infection with the helminth parasite Angiostrongylus cantonensis. B. glabrata and P. soleiformis were experimentally infected with A. cantonensis. Fecal DNAs from control and infected groups were extracted and subjected to 16S rRNA high-throughput sequencing survey. No significant differences were found in the alpha diversity indexes in Phyllocaulis and Biomphalaria experiments independently. PCoA analysis using the unweighted UniFrac measures showed that both microbiotas behaved differently depending on the host. In Biomphalaria microbiota, control and infected groups were significantly different (p = 0.0219), while Phyllocaulis samples were not (p = 0.5190). The microbiome of P. soleiformis infected with A. cantonensis showed a significant decrease of Sphingobacterium and a substantial increase of Cellvibrio when compared to a control group. The microbiome of B. glabrata infected with A. cantonensis showed a significant decline in the abundance of Flavobacterium, Fluviicola, Nitrospira, Vogesella and an OTU belonging to the family Comamonadaceae, and a significant increase of Uliginosibacterium and an OTU belonging to the family Weeksellaceae when compared to a control group. Overall, the microbiome data reported here provided valuable information with regard to the diversity of bacterial communities that comprise the gut microbiome of gastropods. Furthermore, we report here the effect of the infection of the helminth A. cantonensis in the ratio and distribution of the fecal microbiome of the snails. Further studies are highly valuable in order to better understand those interactions by comparing different microbiome profiles and mollusk models. By now, we anticipate that ecological studies will take significant advantage of these advances, particularly concerning improving our understanding of helminth-microbiome-host interactions.
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Abstract The assessment of environmental communities may lead to the identification of the novel or not-yet-classified organisms. Few studies have focused on the meiofauna of poorly known habitats such as native soils in subtropical... more
Abstract The assessment of environmental communities may lead to the identification of the novel or not-yet-classified organisms. Few studies have focused on the meiofauna of poorly known habitats such as native soils in subtropical forests. We surveyed eukaryotic communities inhabiting soil in an unexplored area of a native Atlantic Forest in southern Brazil using high-throughput sequencing. We analyzed a total of 281,400 sequences using V4 and V9 hypervariable regions of 18S rRNA gene. Opisthokonta was the most abundant supergroup, with Fungi and Metazoa representing an average of 40.6% and 15.8% of the sequences, respectively. Among the metazoan, Nematoda was the second most abundant phylum (4.8%). Isolation and morphological assessment 1745 specimens of nematodes, classified by functional feeding groups as plant parasites (35%), bacterial feeders (30%), omnivores (7%) and predators (5%). Specimens belonged to the class Chromadorea (89.6%) and Enoplea (10.4%).Approximately 65% of them could be morphologically classified only to order level. Results identified a considerable number of newly or still uncharacterized nematodes in soil biota in Atlantic Forest soils. Furthermore, this is the first study in this subtropical area to show that both high throughput sequencing and morphology can give complementary indications of the diversity of nematodes in soil samples.
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The investigation of the glycan repertoire of several organisms has revealed a wide variation in terms of structures and abundance of glycan moieties. Among the parasites, it is possible to observe different sets of glycoconjugates across... more
The investigation of the glycan repertoire of several organisms has revealed a wide variation in terms of structures and abundance of glycan moieties. Among the parasites, it is possible to observe different sets of glycoconjugates across taxa and developmental stages within a species. The presence of distinct glycoconjugates throughout the life cycle of a parasite could relate to the ability of that organism to adapt and survive in different hosts and environments. Carbohydrates on the surface, and in excretory-secretory products of parasites, play essential roles in host–parasite interactions. Carbohydrate portions of complex molecules of parasites stimulate and modulate host immune responses, mainly through interactions with specific receptors on the surface of dendritic cells, leading to the generation of a pattern of response that may benefit parasite survival. Available data reviewed here also show the frequent aspect of parasite immunomodulation of mammalian responses through...
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In this era of increasing demand for sensitive techniques to diagnose schistosomiasis, there is a need for an increased focus on the properties of the parasite eggs. The eggs are not only directly linked to the morbidity of chronic... more
In this era of increasing demand for sensitive techniques to diagnose schistosomiasis, there is a need for an increased focus on the properties of the parasite eggs. The eggs are not only directly linked to the morbidity of chronic infection but are also potential key targets for accurate diagnostics. Eggs were the primary target of diagnostic tools in the past and we argue they could be the target of highly sensitive tools in the future if we focus on characteristics of their structure and shell surface that could be exploited for enhanced detection. In this review, we discuss the current state of knowledge of the physical structures of schistosome eggs and eggshells with a view to identifying pathways to a comprehensive understanding of their role in the host-parasite relationship and pathogenesis of infection, and pathways to new strategies for development of diagnostics.
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Angiostrongylus cantonensis is a parasitic nematode and the main causative agent of human cerebral eosinophilic meningoencephalitis (EoM). A definitive diagnosis of EoM usually requires serologic or molecular analysis of the patient's... more
Angiostrongylus cantonensis is a parasitic nematode and the main causative agent of human cerebral eosinophilic meningoencephalitis (EoM). A definitive diagnosis of EoM usually requires serologic or molecular analysis of the patient's clinical sample. Currently, a 31 kDa antigen is used in immunological tests for this purpose, however as a crude antigen preparation it may present cross-reactivity with other helminthic infections, especially echinococcosis. Heterologous expression studies using prokaryotic systems failed on producing antigenic proteins. The aim of this study was to express and purify three recombinant glycoproteins representing A. cantonensis antigens: ES-7, Lec-5, and 14-3-3, in Chinese hamster ovary (CHO) cells and ES-7 in human embryonic kidney (HEK) cells to develop a source of specific antigens to be used in the diagnosis of angiostrongyliasis. The potential diagnostic value of these three proteins was subsequently characterized in one- and two-dimensional e...
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Control initiatives have successfully reduced the prevalence and intensity of schistosomiasis transmission in several localities around the world. However, individuals that release low numbers of eggs in their feces may not be detected by... more
Control initiatives have successfully reduced the prevalence and intensity of schistosomiasis transmission in several localities around the world. However, individuals that release low numbers of eggs in their feces may not be detected by classical methods that are limited by low sensitivity. Given that accurate estimates of prevalence are key to implementing planning control actions for the elimination of schistosomiasis, new diagnostic tools are needed to effectively monitor infections and confirm transmission interruption. The World Health Organization recommends the Kato-Katz (KK) thick smear as a parasitological test for epidemiological surveys, even though this method has been demonstrated to underestimate prevalence when egg burdens are low. The point-of-care immunodiagnostic for detecting schistosome cathodic circulating antigen (POC-CCA) method has been proposed as a more sensitive substitute for KK in prevalence estimations. An alternative diagnostic, the Helmintex (HTX) m...
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Eosinophilic meningitis caused by Angiostrongylus cantonensis is spreading worldwide, and it can manifest as a severe neurological disease. Angiostrongyliasis is a food- and water-borne parasitosis that usually exhibits a seasonal and... more
Eosinophilic meningitis caused by Angiostrongylus cantonensis is spreading worldwide, and it can manifest as a severe neurological disease. Angiostrongyliasis is a food- and water-borne parasitosis that usually exhibits a seasonal and circumscribed geographical distribution. To improve control and treatment of these infections, further studies of transmission dynamics under natural conditions and the development of better diagnostic tools and treatment options are needed.