Functional Feeding Group composition and attributes: evaluation of freshwater ecosystems in Atlantic Forest, Brazil / Composição e atributos de Grupos Funcionais Alimentares: avaliação de ecossistemas de água doce na Mata Atlântica, Brasil

Abstract: Benthic macroinvertebrates Functional Feeding Group (FFG) have been used to determine aquatic assemblage dynamics and as a biomonitoring tool. The main goals of this study were to assess the effects of stream variables on the abundance and richness of FFGs and evaluate ecosystem attributes (FFG ratios) as a tool to assess ecological conditions of Atlantic Rainforest streams. We sampled 146 sites with different impairment conditions in Rio de Janeiro, Brazil. Richness was significantly different among impairment conditions for all FFGs. Mixed-effect models show that aquatic macroinvertebrate FFGs differed in their responses to abiotic variables for abundance and richness. Also, they were reduced in the impaired sites when compared to intermediate and reference sites. The FFG ratio indicated significant differences along the impairment gradient. The FFG ratio analysis was shown to be a fast and cheap tool that can be used for monitoring aquatic ecosystems in the Atlantic Forest biome. However, further studies are required to calibrate the method specifically for the Atlantic Forest region.

Resumo: Os Grupos Funcionais de Alimentação (GFA) são utilizados para determinar a dinâmica da comunidade de macroinvertebrados bentônicos e como uma ferramenta de biomonitoramento. Os principais objetivos deste estudo foram: avaliar os efeitos de variáveis de riacho na abundância e riqueza de GFAs e os atributos do ecossistema (razão GFA) como uma ferramenta para avaliar as condições ecológicas dos córregos da Mata Atlântica. Foram amostrados 146 locais com diferentes condições de impacto no Rio de Janeiro, Brasil. A riqueza foi significativamente diferente com as condições de impacto entre todos os GFA. Os modelos de efeito misto mostraram que os GFA diferiam em suas respostas às variáveis abióticas quanto à abundância e riqueza. Além disso, eles diferem nas áreas impactadas quando comparados as áreas intermediária e de referência. A razão de GFA encontrou diferenças significativas ao longo do gradiente de impacto. A análise da razão de GFA evidenciou-se uma ferramenta rápida e barata, com potencial para ser utilizada no monitoramento de ecossistemas aquáticos no bioma Mata Atlântica. No entanto, mais estudos serão necessários para calibrar o método especificamente para a região da Mata Atlântica.

Exploring the environmental diversity of kinetoplastid flagellates in the high-throughput DNA sequencing era

The class Kinetoplastea encompasses both free-living and parasitic species from a wide range of hosts. Several representatives of this group are responsible for severe human diseases and for economic losses in agriculture and livestock. While this group encompasses over 30 genera, most of the available information has been derived from the vertebrate pathogenic genera Leishmaniaand Trypanosoma. Recent studies of the previously neglected groups of Kinetoplastea indicated that the actual diversity is much higher than previously thought. This article discusses the known segment of kinetoplastid diversity and how gene-directed Sanger sequencing and next-generation sequencing methods can help to deepen our knowledge of these interesting protists.

Molecular and morphological characterization of Contracaecum pelagicum (Nematoda) parasitizing Spheniscus magellanicus (Chordata) from Brazilian waters / Caracterização molecular e morfológica de Contracaecum pelagicum (Nematoda) parasito de Spheniscus magellanicus (Chordata) em águas brasileiras

Three new sequences of Mitochondrial cytochrome c-oxidase subunit 2 (mtDNA cox-2) from C. pelagicum parasite of Spheniscus magellanicus, the Magelanicus penguin, were determined from Brazilian waters. The sequences presented 99 and 98% of similarity with C. pelagicum sequences from Argentina, deposited on GenBank for the same genetic region and with a strong statistical support inferred from the phylogenetic tree. The morphological and ultrastructural studies that were carried out confirmed the genetic analysis.

Foram determinadas três novas sequências da região do Citocromo c-oxidase da subunidade II do DNA mitocondrial (cox-2 mtDNA) de Contracaecum pelagicum, parasito de Spheniscus magellanicus, pinguim Magalhães, de águas brasileiras. As sequências apresentaram 99 e 98% de similaridade com sequências de C. pelagicum da Argentina depositadas no GenBank da mesma região genética com forte suporte estatístico inferido pela arvore filogenética. Estudos morfológicos e ultraestruturais realizados confirmaram a identidade genética.

Frequency of amoebiasis and other intestinal parasitoses in a settlement in Ilheus City, State of Bahia, Brazil

Introduction: This study evaluated the frequency of intestinal parasites, emphasizing the identification and differentiation of Entamoeba spp. Methods: Multiplex polymerase chain reaction (PCR), coproantigen tests and morphometric analysis were performed for Entamoeba spp. differentiation. Results: The overall frequency of intestinal parasites was 65%. Entamoeba histolytica was detected by the coproantigen test, and the PCR showed that Entamoeba dispar predominated in the population. In contrast, morphometric analysis was important for identifying Entamoeba hartmanni. Conclusions: It is possible to identify the causative agent of amoebiasis and to differentiate this agent from other species by combining techniques. .

Comparison of multiplex-PCR and antigen detection for differential diagnosis of Entamoeba histolytica

Amebiasis is an infection caused by Entamoeba histolytica. However, differentiation between E. histolytica and Entamoeba dispar, which are morphologically identical species, is essential for treatment decision, precaution of the invasive disease and public health. The purpose of the present study was to evaluate a Multiplex -PCR for detection and differentiation of E. histolytica from E. dispar from fresh stool samples in comparison with the coproantigen commercial ELISA. Microscopic examination of stools using the Coprotest method, detection of stool antigen by enzyme-linked immunosorbent assay kit and a home made Multiplex-PCR, were used for the diagnosis of amoebiasis infection. Analysis of the 127 stools samples by microscopy examination demonstrated that only 27 (21 percent) samples were positive for E. histolytica/E. dispar complex. Among these stool samples, 11 were positive by Multiplex-PCR, with nine presenting the diagnostic fragment characteristic of E. dispar (96 bp) and two presenting diagnostic fragment of E. histolytica (132 bp). Among negative samples detected by microscopic examination, three positive samples for E. dispar and one positive for E. histolytica by Multiplex-PCR was observed. This denotes a low sensibility of microscopic examination when a single stool sample is analyzed. Assay for detection of E. histolytica antigen was concordant with multiplex-PCR in relation to E. histolytica. Statistical analysis comparing the sensibility tests was not done because of the low number of E. histolytica cases. The results demonstrate the importance of the specific techniques use for the differentiation between E. histolytica and E. dispar.

A importância do diagnóstico laboratorial da estrongiloidíase em pacientes imunossuprimidos / The importance of laboratory diagnosis of strongyloidiasis in immunosuppressed patie

A estrongiloidiase é uma parasitose causada por Strongyloides stercoralis, bastante frequente no Brasil...