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Memórias do Instituto Oswaldo Cruz, Volume: 107, Número: 6, Publicado: 2012
  • Morphological and morphometrical assessment of spermathecae of Aedes aegypti females Articles

    Pascini, Tales Vicari; Ramalho-Ortigão, Marcelo; Martins, Gustavo Ferreira

    Resumo em Inglês:

    The vectorial capacity of Aedes aegypti is directly influenced by its high reproductive output. Nevertheless, females are restricted to a single mating event, sufficient to acquire enough sperm to fertilize a lifetime supply of eggs. How Ae. aegypti is able to maintain viable spermatozoa remains a mystery. Male spermatozoa are stored within either of two spermathecae that in Ae. aegypti consist of one large and two smaller organs each. In addition, each organ is divided into reservoir, duct and glandular portions. Many aspects of the morphology of the spermatheca in virgin and inseminated Ae. aegypti were investigated here using a combination of light, confocal, electron and scanning microscopes, as well as histochemistry. The abundance of mitochondria and microvilli in spermathecal gland cells is suggestive of a secretory role and results obtained from periodic acid Schiff assays of cell apexes and lumens indicate that gland cells produce and secrete neutral polysaccharides probably related to maintenance of spermatozoa. These new data contribute to our understanding of gamete maintenance in the spermathecae of Ae. aegypti and to an improved general understanding of mosquito reproductive biology.
  • Trypanosoma rangeli protein tyrosine phosphatase is associated with the parasite's flagellum Articles

    Prestes, Elisa Beatriz; Bayer-Santos, Ethel; Hermes Stoco, Patrícia; Sincero, Thaís Cristine Marques; Wagner, Glauber; Umaki, Adriana; Fragoso, Stenio Perdigão; Bordignon, Juliano; Steindel, Mário; Grisard, Edmundo Carlos

    Resumo em Inglês:

    Protein tyrosine phosphatases (PTPs) play an essential role in the regulation of cell differentiation in pathogenic trypanosomatids. In this study, we describe a PTP expressed by the non-pathogenic protozoan Trypanosoma rangeli (TrPTP2). The gene for this PTP is orthologous to the T. brucei TbPTP1 and Trypanosoma cruzi (TcPTP2) genes. Cloning and expression of the TrPTP2 and TcPTP2 proteins allowed anti-PTP2 monoclonal antibodies to be generated in BALB/c mice. When expressed by T. rangeli epimastigotes and trypomastigotes, native TrPTP2 is detected as a ~65 kDa protein associated with the parasite's flagellum. Given that the flagellum is an important structure for cell differentiation in trypanosomatids, the presence of a protein responsible for tyrosine dephosphorylation in the T. rangeli flagellum could represent an interesting mechanism of regulation in this structure.
  • Trichomonas vaginalis and Tritrichomonas foetus: interaction with fibroblasts and muscle cells - new insights into parasite-mediated host cell cytotoxicity Articles

    Vilela, Ricardo Chaves; Benchimol, Marlene

    Resumo em Inglês:

    Trichomonas vaginalis and Tritrichomonas foetus are parasitic, flagellated protists that inhabit the urogenital tract of humans and bovines, respectively. T. vaginalis causes the most prevalent non-viral sexually transmitted disease worldwide and has been associated with an increased risk for human immunodeficiency virus-1 infection in humans. Infections by T. foetus cause significant losses to the beef industry worldwide due to infertility and spontaneous abortion in cows. Several studies have shown a close association between trichomonads and the epithelium of the urogenital tract. However, little is known concerning the interaction of trichomonads with cells from deeper tissues, such as fibroblasts and muscle cells. Published parasite-host cell interaction studies have reported contradictory results regarding the ability of T. foetus and T. vaginalis to interact with and damage cells of different tissues. In this study, parasite-host cell interactions were examined by culturing primary human fibroblasts obtained from abdominal biopsies performed during plastic surgeries with trichomonads. In addition, mouse 3T3 fibroblasts, primary chick embryo myogenic cells and L6 muscle cells were also used as models of target cells. The parasite-host cell cultures were processed for scanning and transmission electron microscopy and were tested for cell viability and cell death. JC-1 staining, which measures mitochondrial membrane potential, was used to determine whether the parasites induced target cell damage. Terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling staining was used as an indicator of chromatin damage. The colorimetric crystal violet assay was performed to ana-lyse the cytotoxicity induced by the parasite. The results showed that T. foetus and T. vaginalis adhered to and were cytotoxic to both fibroblasts and muscle cells, indicating that trichomonas infection of the connective and muscle tissues is likely to occur; such infections could cause serious risks to the infected host.
  • The infection of microvascular endothelial cells with ExoU-producing Pseudomonas aeruginosa triggers the release of von Willebrand factor and platelet adhesion Articles

    Freitas, Carla; Assis, Maria-Cristina; Saliba, Alessandra Mattos; Morandi, Veronica Maria; Figueiredo, Camila Castro; Pereira, Mirian; Plotkowski, Maria-Cristina

    Resumo em Inglês:

    An increased plasma concentration of von Willebrand factor (vWF) is detected in individuals with many infectious diseases and is accepted as a marker of endothelium activation and prothrombotic condition. To determine whether ExoU, a Pseudomonas aeruginosa cytotoxin with proinflammatory activity, enhances the release of vWF, microvascular endothelial cells were infected with the ExoU-producing PA103 P. aeruginosa strain or an exoU-deficient mutant. Significantly increased vWF concentrations were detected in conditioned medium and subendothelial extracellular matrix from cultures infected with the wild-type bacteria, as determined by enzyme-linked immunoassays. PA103-infected cells also released higher concentrations of procoagulant microparticles containing increased amounts of membrane-associated vWF, as determined by flow cytometric analyses of cell culture supernatants. Both flow cytometry and confocal microscopy showed that increased amounts of vWF were associated with cytoplasmic membranes from cells infected with the ExoU-producing bacteria. PA103-infected cultures exposed to platelet suspensions exhibited increased percentages of cells with platelet adhesion. Because no modulation of the vWF mRNA levels was detected by reverse transcription-polymerase chain reaction assays in PA103-infected cells, ExoU is likely to have induced the release of vWF from cytoplasmic stores rather than vWF gene transcription. Such release is likely to modify the thromboresistance of microvascular endothelial cells.
  • Cytokines and visceral leishmaniasis: a comparison of plasma cytokine profiles between the clinical forms of visceral leishmaniasis Articles

    Costa, Alinne Silva Andrade; Costa, Graciomar Conceição; Aquino, Dorlene Maria Cardoso de; Mendonça, Vitor Rosa Ramos de; Barral, Aldina; Barral-Netto, Manoel; Caldas, Arlene de Jesus Mendes

    Resumo em Inglês:

    It is not well established whether cytokine production differs in response to different clinical forms of visceral leishmaniasis (VL). In this work, we performed a cross-sectional study to investigate the plasma levels of cytokines [interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-2, IL-4, IL-10 and IL-12] involved in the pathogenesis of VL in 80 subjects from VL endemic areas, including subjects with active VL, subjects with asymptomatic infection, subjects with cured VL and uninfected controls. The patients were recruited by sampling from a referral hospital and by random selection from a population-based cohort study. The results showed significant differences in the plasma concentration of all cytokines between the groups (p < 0.05). Patients with the active disease had higher plasma levels of IL-10, IL-4, INF-γ and TNF-α relative to the other groups and they produced more IL-12 than asymptomatic and cured subjects. Only the IL-2 concentration was higher in the asymptomatic and cured subjects relative to the patients with active disease (p < 0.05). Our results suggest that these cytokines can be used as markers in epidemiological studies conducted in endemic areas to distinguish between different clinical forms of VL. However, their usefulness should be confirmed in investigations conducted in other endemic areas.
  • Angiostrongylus cantonensis (Nematode: Metastrongyloidea) in molluscs from harbour areas in Brazil Articles

    Carvalho, Omar dos Santos; Scholte, Ronaldo Guilherme Carvalho; Mendonça, Cristiane Lafeta Furtado de; Passos, Liana Konovaloff Jannotti; Caldeira, Roberta Lima

    Resumo em Inglês:

    Angiostrongylus cantonensis is the most common aetiological agent of human eosinophilic meningoencephalitis. Following a report indicating the presence of this parasite in Brazil in 2007, the present study was undertaken to investigate the presence of A. cantonensis in the surrounding Brazilian port areas. In total, 30 ports were investigated and the following molluscs were identified: Achatina fulica, Belocaulus sp., Bradybaena similaris sp., Cyclodontina sp., Helix sp., Leptinaria sp., Melampus sp., Melanoides tuberculata, Phyllocaulis sp., Pomacea sp., Pseudoxychona sp., Rhinus sp., Sarasinula marginata, Streptaxis sp., Subulina octona, Succinea sp., Tomigerus sp., Wayampia sp. and specimens belonging to Limacidae and Orthalicinae. Digestion and sedimentation processes were performed and the sediments were examined. DNA was extracted from the obtained larvae and the internal transcribed spacer region 2 was analysed by polymerase chain reaction-restriction fragment length polymorphism after digestion with the endonuclease ClaI. Of the 30 ports investigated in this study, 11 contained molluscs infected with A. cantonensis larvae. The set of infected species consisted of S. octona, S. marginata, A. fulica and B. similaris. A total of 36.6% of the investigated ports were positive for A. cantonensis, indicating a wide distribution of this worm. It remains uncertain when and how A. cantonensis was introduced into South America.
  • Metallo-β-lactamase-production in meropenem-susceptible Pseudomonas aeruginosa isolates: risk for silent spread Articles

    Picão, Renata Cristina; Carrara-Marroni, Floristher Elaine; Gales, Ana Cristina; Venâncio, Emerson José; Xavier, Danilo Elias; Tognim, Maria Cristina Bronharo; Pelayo, Jacinta Sanchez

    Resumo em Inglês:

    The aim of this study was to characterize two metallo-β-lactamases (MBLs)-producing Pseudomonas aeruginosa clinical isolates showing meropenem susceptibility. Antimicrobial susceptibility was assessed by automated testing and Clinical and Laboratory Standards Institute agar dilution method. MBL production was investigated by phenotypic tests. Molecular typing was determined by pulsed field gel electrophoresis (PFGE). MBL-encoding genes, as well as their genetic context, were identified by polymerase chain reaction (PCR) and sequencing. The location of blaIMP-16 was determined by plasmid electrophoresis, Southern blot and hybridization. Transcriptional levels of blaIMP-16, mexB, mexD, mexF, mexY, ampC and oprD were determined by semi-quantitative real time PCR. The P. aeruginosa isolates studied, Pa30 and Pa43, showed imipenem and meropenem susceptibility by automated testing. Agar dilution assays confirmed meropenem susceptibility whereas both isolates showed low level of imipenem resistance. Pa30 and Pa43 were phenotypically detected as MBL producers. PFGE revealed their clonal relatedness. blaIMP-16 was identified in both isolates, carried as a single cassette in a class 1 integron that was embedded in a plasmid of about 60-Kb. Pa30 and Pa43 overexpressed MexAB-OprM, MexCD-OprJ and MexXY-OprM efflux systems and showed basal transcriptional levels of ampC and oprD. MBL-producing P. aeruginosa that are not resistant to meropenem may represent a risk for therapeutic failure and act as silent reservoirs of MBL-encoding genes.
  • Proteolytic activity in the adult and larval stages of the human roundworm parasite Angiostrongylus costaricensis Articles

    Rebello, Karina Mastropasqua; Siqueira, Caroline Reis de; Ribeiro, Erika Louise; Valente, Richard Hemmi; Mota, Ester Maria; Perales, Jonas; Neves-Ferreira, Ana Gisele da Costa; Lenzi, Henrique Leonel

    Resumo em Inglês:

    Angiostrongylus costaricensis is a nematode that causes abdominal angiostrongyliasis, a widespread human parasitism in Latin America. This study aimed to characterize the protease profiles of different developmental stages of this helminth. First-stage larvae (L1) were obtained from the faeces of infected Sigmodon hispidus rodents and third-stage larvae (L3) were collected from mollusks Biomphalaria glabrata previously infected with L1. Adult worms were recovered from rodent mesenteric arteries. Protein extraction was performed after repeated freeze-thaw cycles followed by maceration of the nematodes in 40 mM Tris base. Proteolysis of gelatin was observed by zymography and found only in the larval stages. In L3, the gelatinolytic activity was effectively inhibited by orthophenanthroline, indicating the involvement of metalloproteases. The mechanistic class of the gelatinases from L1 could not be precisely determined using traditional class-specific inhibitors. Adult worm extracts were able to hydrolyze haemoglobin in solution, although no activity was observed by zymography. This haemoglobinolytic activity was ascribed to aspartic proteases following its effective inhibition by pepstatin, which also inhibited the haemoglobinolytic activity of L1 and L3 extracts. The characterization of protease expression throughout the A. costaricensis life cycle may reveal key factors influencing the process of parasitic infection and thus foster our understanding of the disease pathogenesis.
  • A study of multidrug-resistant tuberculosis in risk groups in the city of Santos, São Paulo, Brazil Articles

    Coelho, Andréa Gobetti Vieira; Zamarioli, Liliana Aparecida; Telles, Maria Alice; Ferrazoli, Lucilaine; Waldman, Eliseu Alves

    Resumo em Inglês:

    Monitoring the extent of and trends in multidrug-resistant tuberculosis (MDR-TB) is a priority of the Brazilian National Tuberculosis Control Programme. The current study aimed to estimate the incidence of MDR-TB, describe the profile of TB drug resistance in risk groups and examine whether screening for MDR-TB adhered to the recommended guidelines. A descriptive study that examined diagnosed cases of pulmonary TB was conducted in the city of Santos, Brazil, between 2000-2004. Of the 2,176 pulmonary TB cases studied, 671 (30.8%) met the criteria for drug sensitivity testing and, of these cases, 31.7% (213/671) were tested. Among the tested cases, 9.4% were resistant to one anti-TB drug and 15% were MDR. MDR was observed in 11.6% of 86 new TB cases and 17.3% of 127 previously treated cases. The average annual incidence of MDR-TB was 1.9 per 100,000 inhabitants-years. The extent of known MDR-TB in the city of Santos is high, though likely to be underestimated. Our study therefore indicates an inadequate adherence to the guidelines for MDR-TB screening and suggests the necessity of alternative strategies of MDR-TB surveillance.
  • Lutzomyia longipalpis abundance in the city of Posadas, northeastern Argentina: variations at different spatial scales Articles

    Santini, María Soledad; Fernández, María Soledad; Pérez, Adriana Alicia; Sandoval, Adolfo Enrique; Salomón, Oscar Daniel

    Resumo em Inglês:

    The distribution of Lutzomyia longipalpis is heterogeneous with a pattern of high abundance areas (HAAs) embedded in a matrix of low abundance areas (LAAs). The objective of this study was to describe the variability in the abundance of Lu. longipalpis at two different spatial levels and to analyse the relationship between the abundance and multiple environmental variables. Of the environmental variables analysed in each household, the condition that best explained the differences in vector abundance between HAA-LAA was the variable "land_grass", with greater average values in the peridomestic environments within the LAA, and the variables "#sp tree", "#pots" and "dist_water" that were higher in the HAA. Of the environmental variables analysed in the patches, the variable "unpaved_streets" was higher in the LAAs and the variable "prop_inf_dogs" was higher in the HAAs. An understanding of the main environmental variables that influence the vector distribution could contribute to the development of strategies for the prevention and control of visceral leishmaniasis (VL). This is the first work in which environmental variables are analysed at the micro-scale in urban areas at the southern edge of the current range of Lu. longipalpis. Our results represent a significant contribution to the understanding of the abundance of the vector in the peridomestic habitats of the region.
  • Molecular characterisation of Bartonella species in cats from São Luís, state of Maranhão, north-eastern Brazil Articles

    Braga, Maria do Socorro Costa de Oliveira; Diniz, Pedro Paulo Vissotto de Paiva; André, Marcos Rogério; de Bortoli, Caroline Plácidi; Machado, Rosangela Zacarias

    Resumo em Inglês:

    Bartonella species are fastidious bacteria that predominantly infect mammalian erythrocytes and endothelial cells and cause long-lasting bacteraemia in their reservoir hosts. Reports that describe the epidemiology of bartonellosis in Brazil are limited. This study aimed to detect and characterise Bartonella spp DNA from cat blood samples in São Luís, Maranhão, north-eastern Brazil. Among 200 cats tested for multiple genes, nine (4.5%) were positive for Bartonella spp: six cats for Bartonella henselae and three for Bartonella clarridgeiae. Based on the phylogenetic analysis of four genes, the B. henselae strain matched strains previously observed in Brazil and was positioned in the same clade as B. henselae isolates from the United States of America. Moreover, sequence alignment demonstrated that the B. clarridgeiae strain detected in the present study was the same as the one recently detected in cats from southern Brazil.
  • Detection of enteric viruses in recreational waters of an urban lagoon in the city of Rio de Janeiro, Brazil Articles

    Vieira, Carmen Baur; Mendes, Anna Carolina de Oliveira; Guimarães, Flávia Ramos; Fumian, Tulio Machado; Leite, José Paulo Gagliardi; Gaspar, Ana Maria Coimbra; Miagostovich, Marize Pereira

    Resumo em Inglês:

    The aim of this study was to determine the occurrences of the group A rotavirus (RVA), norovirus (NoV) and human adenovirus (HAdV) in the surface waters of an urban lagoon (Rodrigo de Freitas Lagoon) in the city of Rio de Janeiro, Brazil. During one year of surveillance, water samples were obtained from the lagoon and other interconnected ecosystems (river and beach). The samples were concentrated using an adsorption-elution method with a negatively charged membrane and tested by qualitative and quantitative polymerase chain reaction assays. RVA was the most prevalent virus detected (24.3%) with a viral load ranging from 3.0 x 10¹-5.6 x 10(4) genome copies/L, followed by NoV (18.8%) and HAdV (16.7%). Considering water samples suitable for bathing, according to Escherichia coli criterion (< 2,000 most probable number/100 mL), viruses were detected in 50% (57/114) of them. Physicochemical parameters were also measured and showed possible correlations between turbidity and RVA presence and between pH and NoV presence. These data demonstrate the importance of considering viral parameters to ensure water quality and the utilisation of these parameters as additional tools for the characterisation of environmental contamination.
  • Hepatitis B virus genotypes in Southeast Brazil and its relationship with histological features Articles

    Nabuco, Leticia Cancella; Mello, Francisco Campello do Amaral; Gomes, Selma de Andrade; Perez, Renata Mello; Soares, Jorge André Segadas; Coelho, Henrique Sérgio Moraes; Nogueira, Cristiane Alves Villela

    Resumo em Inglês:

    Data concerning the relationship between hepatitis B virus (HBV) genotypes and liver histology are scarce. The aim of this study was to compare HBV non-B and non-C genotypes according to demographic features, clinical status, HBV-DNA levels and liver histology in Rio de Janeiro. One hundred twenty one consecutive chronic HBV-infected patients were enrolled during two-year period and data were prospectively collected. Sera were tested for HBV genotyping using restriction fragment length polymorphism. Liver biopsy was obtained from patients with either increased alanine aminotransferase (ALT) or HBV-DNA levels. Genotype A was the most common, found in 82 (68%) patients, followed by F in 19 (15%), D in 17 (14%), B in one (1%) and C in two (2%). There was no association between HBV genotypes A, D and F and gender (p = 0.37), age (p = 0.78), race (p = 0.22), mode of infection (p = 0.94), HB "e" antigen status (p = 0.37) and HBV-DNA levels (p = 0.47). The ALT levels were lower in genotype D (75%) compared with A (47%) and F (55%) (p = 0.05). Liver biopsy showed lower inflammation [histological activity index (HAI) = 4] and fibrosis (F) (= 0) scores in genotype D than in genotypes A (HAI = 5, p < 0.001; F = 2, p = 0.008) or F (HAI = 5, p = 0.009; F = 2, p = 0.01). Genotype A was the most prevalent in chronic HBV-infected patients and genotype D patients presented with less intense liver disease.
  • The zinc finger protein TcZFP2 binds target mRNAs enriched during Trypanosoma cruzi metacyclogenesis Articles

    Mörking, Patricia Alves; Rampazzo, Rita de Cássia Pontello; Walrad, Pegine; Probst, Christian Macagnan; Soares, Maurilio José; Gradia, Daniela Fiori; Pavoni, Daniela Parada; Krieger, Marco Aurélio; Matthews, Keith; Goldenberg, Samuel; Fragoso, Stenio Perdigão; Dallagiovanna, Bruno

    Resumo em Inglês:

    Trypanosomes are parasitic protozoa in which gene expression is primarily controlled through the regulation of mRNA stability and translation. This post-transcriptional control is mediated by various families of RNA-binding proteins, including those with zinc finger CCCH motifs. CCCH zinc finger proteins have been shown to be essential to differentiation events in trypanosomatid parasites. Here, we functionally characterise TcZFP2 as a predicted post-transcriptional regulator of differentiation in Trypanosoma cruzi. This protein was detected in cell culture-derived amastigotes and trypomastigotes, but it was present in smaller amounts in metacyclic trypomastigote forms of T. cruzi. We use an optimised recombinant RNA immunopreciptation followed by microarray analysis assay to identify TcZFP2 target mRNAs. We further demonstrate that TcZFP2 binds an A-rich sequence in which the adenosine residue repeats are essential for high-affinity recognition. An analysis of the expression profiles of the genes encoding the TcZFP2-associated mRNAs throughout the parasite life cycle by microarray hybridisation showed that most of the associated mRNAs were upregulated in the metacyclic trypomastigote forms, also suggesting a role for TcZFP2 in metacyclic trypomastigote differentiation. Knockdown of the orthologous Trypanosoma brucei protein levels showed ZFP2 to be a positive regulator of specific target mRNA abundance.
  • Human bocavirus 1 and 3 infection in children with acute gastroenteritis in Brazil Articles

    Sousa, Teresinha Teixeira de; Souza, Menira; Fiaccadori, Fabíola Souza; Borges, Ana Maria Tavares; Costa, Paulo Sucasas da; Cardoso, Divina das Dôres de Paula

    Resumo em Inglês:

    To determine the positivity rate of human bocavirus (HBoV) 1 and 3 among children who presented with acute gastroenteritis symptoms during the period of 1994-2004 in the Central-West Region of Brazil, 762 faecal samples were tested using polymerase chain reaction (PCR) for the detection of HBoV DNA. Primers for a segment of the non-structural viral protein 1 (NS1) gene of HBoV-1 and HBoV-3 were used. Twelve HBoV-positive samples were further characterised via genomic sequencing and phylogenetic analysis. Of the samples tested, 5.8% (n = 44) were positive for HBoV-1 or HBoV-3 and co-infection was observed in 14 (31.8%) of the 44 HBoV-positive samples. Nine of the 14 samples were also positive for Rotavirus A and five were positive for Aichi virus. The genomic sequencing of the NS1 partial sequence of 12 HBoV-samples showed that 11 samples were characterised as HBoV-1 and that one was characterised as HBoV-3. The phylogenetic analysis showed that the HBoV-1 samples had a high sequence homology to others previously identified in China, Sweden and Brazil. This is the first study conducted in the Central-West Region of Brazil to detect HBoV-1 and HBoV-3 in faecal samples from children with acute gastroenteritis. Further studies are required to define the role of HBoVs as aetiological agents of gastroenteritis.
  • Molecular characterisation of dengue virus type 1 reveals lineage replacement during circulation in Brazilian territory Articles

    Carneiro, Adriana Ribeiro; Cruz, Ana Cecília Ribeiro; Vallinoto, Marcelo; Melo, Diego de Vasconcelos; Ramos, Rommel Thiago J; Medeiros, Daniele Barbosa Almeida; Silva, Eliana Vieira Pinto da; Vasconcelos, Pedro Fernando da Costa

    Resumo em Inglês:

    Dengue fever is the most important arbovirus infection found in tropical regions around the world. Dispersal of the vector and an increase in migratory flow between countries have led to large epidemics and severe clinical outcomes, such as dengue haemorrhagic fever and dengue shock syndrome. This study analysed the genetic variability of the dengue virus serotype 1 (DENV-1) in Brazil with regard to the full-length structural genes C/prM/M/E among 34 strains isolated during epidemics that occurred in the country between 1994-2011. Virus phylogeny and time of divergence were also evaluated with only the E gene of the strains isolated from 1994-2008. An analysis of amino acid differences between these strains and the French Guiana strain (FGA/89) revealed the presence of important nonsynonymous substitutions in the amino acid sequences, including residues E297 (Met→Thr) and E338 (Ser→Leu). A phylogenetic analysis of E proteins comparing the studied isolates and other strains selected from the GenBank database showed that the Brazilian DENV-1 strains since 1982 belonged to genotype V. This analysis also showed that different introductions of strains from the 1990s represented lineage replacement, with the identification of three lineages that cluster all isolates from the Americas. An analysis of the divergence time of DENV-1 indicated that the lineage circulating in Brazil emerged from an ancestral lineage that originated approximately 44.35 years ago.
  • Coccidioidomycosis in armadillo hunters from the state of Ceará, Brazil Short Communications

    Brillhante, Raimunda Sâmia Nogueira; Moreira Filho, Renato Evando; Rocha, Marcos Fábio Gadelha; Castelo-Branco, Débora de Souza Collares Maia; Fechine, Maria Auxiliadora Bezerra; Lima, Rita Amanda Chaves de; Picanço, Yuri Vieira Cunha; Cordeiro, Rossana de Aguiar; Camargo, Zoilo Pires de; Queiroz, José Ajax Nogueira; Araujo, Roberto Wagner Bezerra de; Mesquita, Jacó Ricarte Lima de; Sidrim, José Júlio Costa

    Resumo em Inglês:

    Coccidioidomycosis is a systemic mycosis with a variable clinical presentation. Misdiagnosis of coccidioidomycosis as bacterial pneumopathy leads to inappropriate prescription of antibiotics and delayed diagnosis. This report describes an outbreak among armadillo hunters in northeastern Brazil in which an initial diagnosis of bacterial pneumonia was later confirmed as coccidioidomycosis caused by Coccidioides posadasii. Thus, this mycosis should be considered as an alternative diagnosis in patients reporting symptoms of pneumonia, even if these symptoms are only presented for a short period, who are from areas considered endemic for this disease.
  • Distinct subcellular localization of tRNA-derived fragments in the infective metacyclic forms of Trypanosoma cruzi Short Communications

    Reifur, Larissa; Garcia-Silva, Maria Rosa; Poubel, Saloê Bispo; Alves, Lysangela Ronalte; Arauco, Paulo; Buiar, Diane Kelly; Goldenberg, Samuel; Cayota, Alfonso; Dallagiovanna, Bruno

    Resumo em Inglês:

    Small non-coding RNAs derived from transfer RNAs have been identified as a broadly conserved prokaryotic and eukaryotic response to stress. Their presence coincides with changes in developmental state associated with gene expression regulation. In the epimastigote form of Trypanosoma cruzi, tRNA fragments localize to posterior cytoplasmic granules. In the infective metacyclic form of the parasite, we found tRNA-derived fragments to be abundant and evenly distributed within the cytoplasm. The fragments were not associated with polysomes, suggesting that the tRNA-derived fragments may not be directly involved in translation control in metacyclics.
  • The in vivo antimalarial activity of methylene blue combined with pyrimethamine, chloroquine and quinine Short Communications

    Garavito, Giovanny; Bertani, Stéphane; Quiliano, Miguel; Valentin, Alexis; Aldana, Ignacio; Deharo, Eric

    Resumo em Inglês:

    The effectiveness of methylene blue (MB) combined with pyrimethamine (PYR), chloroquine (CQ) or quinine (Q) was examined in a classical four-day suppressive test against a causative agent of rodent malaria, Plasmodium berghei. A marked potentiation was observed when MB was administered at a non-curative dose of 15 mg/kg/day in combination with PYR (0.19 mg/kg/day) or Q (25 mg/kg/day). No synergy was found between MB (15 mg/Kg) and CQ (0.75 mg/Kg). Our results suggest that the combination of MB with PYR or Q may improve the efficacy of these currently used antimalarial drugs.
  • Upregulation of hsa-miR-125b in HTLV-1 asymptomatic carriers and HTLV-1-associated myelopathy/tropical spastic paraparesis patients Short Communications

    Nicolete, Larissa Deadame de Figueiredo; Nicolete, Roberto; Haddad, Rodrigo; Azevedo, Rochele; Castro, Fabíola Attié de; Tanaka, Yuetsu; Takayanagui, Osvaldo Massaiti; Covas, Dimas Tadeu; Kashima, Simone

    Resumo em Inglês:

    The retrovirus human T lymphotropic virus type 1 (HTLV-1) promotes spastic paraparesis, adult T cell leukaemia and other diseases. Recently, some human microRNAs (miRNAs) have been described as important factors in host-virus interactions. This study compared miRNA expression in control individuals, asymptomatic HTLV-1 carriers and HTLV-1 associated myelopathy (HAM)/tropical spastic paraparesis patients. The proviral load and Tax protein expression were measured in order to characterize the patients. hsa-miR-125b expression was significantly higher in patients than in controls (p = 0.0285) or in the HAM group (p = 0.0312). Therefore, our findings suggest that miR-125b expression can be used to elucidate the mechanisms of viral replication and pathogenic processes.
  • Why do we need alternative tools to control mosquito-borne diseases in Latin America? Reader's Opinion

    Maciel-de-Freitas, Rafael; Aguiar, Raquel; Bruno, Rafaela V; Guimarães, Maria Cristina; Lourenço-de-Oliveira, Ricardo; Sorgine, Marcos HF; Struchiner, Cláudio J; Valle, Denise; O'Neill, Scott L; Moreira, Luciano A

    Resumo em Inglês:

    In this opinion paper, we discuss the potential and challenges of using the symbiont Wolbachia to block mosquito transmitted diseases such as dengue, malaria and chikungunya in Latin America.
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