Chikungunya risk for Brazil

<div><p>This study aimed to show, based on the literature on the subject, the potential for dispersal and establishment of the chikungunya virus in Brazil. The chikungunya virus, a Togaviridae member of the genusAlphavirus, reached the Americas in 2013 and, the following year, more than a million cases were reported. In Brazil, indigenous transmission was registered in Amapa and Bahia States, even during the period of low rainfall, exposing the whole country to the risk of virus spreading. Brazil is historically infested by Ae. aegypti and Ae. albopictus, also dengue vectors. Chikungunya may spread, and it is important to take measures to prevent the virus from becoming endemic in the country. Adequate care for patients with chikungunya fever requires training general practitioners, rheumatologists, nurses, and experts in laboratory diagnosis. Up to November 2014, more than 1,000 cases of the virus were reported in Brazil. There is a need for experimental studies in animal models to understand the dynamics of infection and the pathogenesis as well as to identify pathophysiological mechanisms that may contribute to identifying effective drugs against the virus. Clinical trials are needed to identify the causal relationship between the virus and serious injuries observed in different organs and joints. In the absence of vaccines or effective drugs against the virus, currently the only way to prevent the disease is vector control, which will also reduce the number of cases of dengue fever.</p></div

Revalidation and genetic characterization of new members of Group C (<i>Orthobunyavirus</i> genus, <i>Peribunyaviridae</i> family) isolated in the Americas

<div><p>Group C serogroup includes members of the <i>Orthobunyavirus</i> genus (family <i>Peribunyaviridae</i>) and comprises 15 arboviruses that can be associated with febrile illness in humans. Although previous studies described the genome characterization of Group C orthobunyavirus, there is a gap in genomic information about the other viruses in this group. Therefore, in this study, complete genomes of members of Group C serogroup were sequenced or re-sequenced and used for genetic characterization, as well as to understand their phylogenetic and evolutionary aspects. Thus, our study reported the genomes of three new members in Group C virus (Apeu strain BeAn848, Itaqui strain BeAn12797 and Nepuyo strain BeAn10709), as well as re-sequencing of original strains of five members: Caraparu (strain BeAn3994), Madrid (strain BT4075), Murucutu (strain BeAn974), Oriboca (strain BeAn17), and Marituba (strain BeAn15). These viruses presented a typical genomic organization related to members of the <i>Orthobunyavirus</i> genus. Interestingly, all viruses of this serogroup showed an open reading frame (ORF) that encodes the putative nonstructural NSs protein that precedes the nucleoprotein ORF, an unprecedented fact in Group C virus. Also, we confirmed the presence of natural reassortment events. This study expands the genomic information of Group C viruses, as well as revalidates the genomic organization of viruses that were previously reported.</p></div

Group C viruses used in the present study.

<p>Group C viruses used in the present study.</p

Reassortment events in Group C viruses.

<p>(a) Apeu, (b) Itaqui, (c) Oriboca and (d) Summary of RDP4 analysis to determine potential reassortants.</p

ML phylogenetic trees based on alignments of nucleotide sequences of Group C viruses.

<p>(a) S segment (b) M segment and (c) L segment. Phylogenies are midpoint rooted for clarity of presentation. The scale bar indicates evolutionary distance in numbers of substitutions per nucleotides substitutions/site, and the principal bootstrap support levels were indicated. Branches are colour-coded according to group. Viruses strains sequenced in this study are highlighted with red color. The Bimiti, Guama, Catu and Mahogany hammock were used as outgroup. Pairwise distance based on alignments of nucleotide sequences of Group C viruses with (d) S segment (e) M segment and (f) L segment.</p

Genome organization of Group C viruses.

<p>(a) Apeu, (b) Caraparu, (c) Itaqui, (d) Madrid, (e) Marituba, (f) Murucutu, (g) Nepuyo and (h) Oriboca.</p

Alignment of non-structural protein of Group C viruses.

<p>Alignment of non-structural protein of Group C viruses.</p

Transmission electron photomicrographs of ultrathin sections obtained from control (A) and mouse brain infected intracerebrally with Curionopolis for 36 (B,C), 60 (D) and 96 h (E), and with Itacaiunas for 24 (F), 60 (G), 72 (H), 96 (I) and 108 h (J).

<p>Normal tissue with intact neuronal soma and appendages (A); viral particles (arrow), interstitial edema (stars) and cellular rarefaction (lozenge) are seen 36 h post-inoculation (p.i.) (B, C); necrotic cells were observed at 60 h p.i. (D); intense perivascular edema (stars), hyperplastic endotheliocytes and reduced vessel luminal area (E); well-preserved brain parenchyma and vessels at 24 h p.i. (F); viral particles, endotheliocyte hyperplasia, and mild interstitial edema (stars) at 60 h p.i. (G); membrane viral budding in rich polyribosomes oligodendrocyte-like cell at 72 h p.i. (H); brain parenchyma at 96 h p.i. presenting a large number of viral particles (I); apoptotic features were more marked at 108 h p.i. (J). AC = apoptotic cell, M = mitochondria, OL = oligodendrocyte, EC = endothelial cells, VL = vascular lumen, N = cell nucleus, NC = necrotic cells.</p

Transmission electron photomicrographs of ultrathin sections obtained from primary neuronal cultures.

<p>Control cultures of normal cells (A) and after Itacaiunas (B) and Curionopolis (C, D) infection at 4 and 5 days post-inoculation, respectively. Apoptotic cells (C) and virus budding (rectangle and arrows) (C, D) after Curionopolis infection. Itacaiunas virus particles (arrows) in culture at 5 days post-inoculation (B). N: nucleus; AN: apoptotic nucleus.</p

Combined interferential contrast and fluorescent photomicrographs of positive and negative controls (A, B) and Curionopolis- (C, D) or Itacaiunas (E,F)-infected neurons after TUNEL immunolabeling.

<p>Apoptotic nuclei (arrows) are observed in control cultures exposed to UV light (A) and after Curionopolis (D) and Itacaiunas (F) virus inoculation at 4 and 5 days post-inoculation, respectively. Negative control cultures (B) and infected cultures at 1 day post-inoculation (C, E) present few stained nuclei.</p