Detection of a New Yellow Fever Virus Lineage Within the South American Genotype I in Brazil

Nucleotide sequences of two regions of the genomes of 11 yellow fever virus (YFV) samples isolated from monkeys or humans with symptomatic yellow fever (YF) in Brazil in 2000,2004, and 2008 were determined with the objective of establishing the genotypes and studying the genetic variation. Results of the Bayesian phylogenetic analysis showed that sequences generated from strains from 2004 and 2008 formed a new subclade within the clade 1 of the South American genotype I. The new subgroup is here designated as 1E. Sequences of YFV strains recovered in 2000 belong to the subclade 1D, which comprises previously characterized YFV strains from Brazil. Molecular dating analyses suggested that the new subclade 1E started diversifying from 1D about 1975 and that the most recent 2004-2008 isolates arose about 1985. J. Med. Virol. 82:175-185, 2010. (C) 2009 Wiley-Liss, Inc.

Detection of a new mumps virus genotype during parotitis epidemic of 2006-2007 in the state of Sao Paulo, Brazil

Nucleoticle sequence analyses of the SH gene of 18 mumps virus isolates collected in the 2006-2007 parotitis epidemic in the state of Sao Paulo identified a new genotype, designated genotype M. This new designation fulfills all the parameters required to define a new mumps virus genotype. The parameters were established by an expert panel in collaboration with the World Health Organization (WHO) in 2005. This information will enhance the mumps virus surveillance program both at the national and global levels.

Clinical evaluation and COL2A1 gene analysis in 21 Brazilian families with Stickler syndrome: Identification of novel mutations, further genotype/phenotype correlation, and its implications for the diagnosis

We present clinical and molecular evaluation from a large cohort of patients with Stickler syndrome: 78 individuals from 21 unrelated Brazilian families. The patients were selected in a Hospital with a craniofacial dysmorphology assistance service and clinical diagnosis was based on the presence of cleft palate associated to facial and ocular anomalies of Stickler syndrome. Analysis of COL2A1 gene revealed 9 novel and 4 previously described pathogenic mutations. Except for the mutation c.556G>T (p.Gly186X), all the others were located in the triple helical domain. We did not find genotype/phenotype correlation in relation to type and position of the mutation in the triple helical domain. However, a significantly higher proportion of myopia in patients with mutations located in this domain was observed in relation to those with the mutation in the non-tripe helical domain (c.556G>T; P < 0.04). A trend towards a higher prevalence of glaucoma, although not statistically significant, was observed in the presence of the mutation c.556G>T. It is possible. that this mutation alters the splicing of the mRNA instead of only creating a premature stop codon and therefore it can lead to protein products of different ocular effects. One novel DNA variation (c.1266+7G>C) occurs near a splice site and it was observed to co-segregate with the phenotype in one of the two families with this DNA variation. As in silico analysis predicted that the c.1266+7G>C DNA variation can affect the efficiency of the splicing, we still cannot rule it out as non-pathogenic. Our study also showed that ascertainment through cleft palate associated to other craniofacial signs can be very efficient for identification of Stickler syndrome patients. Still, high frequency of familial cases and high frequency of underdevelopment of distal lateral tibial epiphyses observed in our patients suggested that the inclusion of this information can improve the clinical diagnosis of Stickler syndrome. (C) 2008 Elsevier Masson SAS. All rights reserved.

Relation of pretreatment sequence diversity in NS5A region of HCV genotype 1 with immune response between pegylated-INF/ribavirin therapy outcomes

Hepatitis C virus (HCV) infection frequently persists despite substantial virus-specific immune responses and the combination of pegylated interferon (INF)-alpha and ribavirin therapy. Major histocompatibility complex class I restricted CD8+ T cells are responsible for the control of viraemia in HCV infection, and several studies suggest protection against viral infection associated with specific HLAs. The reason for low rates of sustained viral response (SVR) in HCV patients remains unknown. Escape mutations in response to cytotoxic T lymphocyte are widely described; however, its influence in the treatment outcome is ill understood. Here, we investigate the differences in CD8 epitopes frequencies from the Los Alamos database between groups of patients that showed distinct response to pegylated alpha-INF with ribavirin therapy and test evidence of natural selection on the virus in those who failed treatment, using five maximum likelihood evolutionary models from PAML package. The group of sustained virological responders showed three epitopes with frequencies higher than Non-responders group, all had statistical support, and we observed evidence of selection pressure in the last group. No escape mutation was observed. Interestingly, the epitope VLSDFKTWL was 100% conserved in SVR group. These results suggest that the response to treatment can be explained by the increase in immune pressure, induced by interferon therapy, and the presence of those epitopes may represent an important factor in determining the outcome of therapy.

Apolipoprotein E genotype is related to nitric oxide production in platelets

The presence of the, 4 allele of apolipoprotein E (APOE) is considered a risk factor for sporadic Alzheimer`s disease (AD). Our recent data demonstrated that the systemic modulation of oxidative stress in platelets and erythrocytes is disrupted in aging and AD. In this study, the relationship between APOE genotype and oxidative stress markers, both in AD patients and controls, was evaluated. The AD group showed an increase in the content of thiobarbituric acid-reactive substances (TBARS) and in the activities of nitric oxide synthase (NOS) and Na, K-ATPase, when compared to controls. Both groups had a similar cGMP content and superoxide dismutase activity. APOE epsilon 4 allele carriers showed higher NOS activity than non-carriers. These results suggest a possible influence of APOE genotype on nitric oxide (NO) production that might enhance the effects of age-related specific factor(s) associated with neurodegenerative disorders. Copyright (C) 2008 John Wiley & Sons, Ltd.

Isolation and genotype analysis of rubella virus from a case of Guillain-Barre syndrome

Rubella virus (RV) infection has sporadically been linked to Guillain-Barre syndrome (GBS), but the association with RV has been based only on clinical and/or serological backgrounds. In the present case it was possible to isolate RV (genotype 1a) from cerebrospinal fluid and peripheral blood mononuclear cells of an 18-year-old woman diagnosed with GBS after clinical manifestations of rubella. This report contributes to confirm RV as one of the triggering pathogens of this peripheral nervous system disease. (C) 2008 Elsevier B.V. All rights reserved.

Evolutionary history of Dengue virus type 4: Insights into genotype phylodynamics

Dengue virus type 4 (DENV-4) circulates in tropical and subtropical countries from Asia and the Americas. Despite the importance of dengue virus distribution, little is known about the worldwide viral spread. Following a Bayesian phylogenetic approach we inferred the evolutionary history of 310 isolates sampled from 37 countries during the time period 1956-2008 and the spreading dynamics for genotypes I and II. The region (tropical rainforest biome) comprised by Malaysia-Thailand was the most likely ancestral area from which the serotype has originated and spread. Interestingly, cross-correlation analysis on demographic time series with the Asian sequences showed a statistically significant negative correlation that could be suggestive of competition among genotypes within the same serotype. (C) 2011 Elsevier B.V. All rights reserved.

Phylogenetic analysis of a near-full-length sequence of an erythrovirus genotype 3 strain isolated in Brazil

Human parvovirus B19 is the only member of the genus Erythrovirus that causes human disease. Recent findings of several strains with considerable sequence divergence from B19 have suggested a new classification for parvovirus genotypes as 1 (B19), 2 (A-6 and LaLi) and 3 (V9). In their overall DNA sequence, the three genotypes differ by similar to 10%. Here, we report the isolation of a genotype-3-related strain named BR543 during a prospective study conducted in Sao Paulo, Brazil. Analysis of the nearly full-length genome sequence of BR543 indicates that this B19 variant sequence clusters with Gh2768, a strain from Ghana belonging to subtype 3b, and showed mostly synonymous substitutions.

A new genotype of Trypanosoma cruzi associated with bats evidenced by phylogenetic analyses using SSU rDNA, cytochrome b and Histone H2B genes and genotyping based on ITS1 rDNA

We characterized 15 Trypanosoma cruzi isolates from bats captured in the Amazon, Central and Southeast Brazilian regions. Phylogenetic relationships among T. cruzi lineages using SSU rDNA, cytochrome b, and Histone H2B genes positioned all Amazonian isolates into T. cruzi I (TCI). However, bat isolates from the other regions, which had been genotyped as T. cruzi II (TC II) by the traditional genotyping method based on mini-exon gene employed in this study, Were not nested within any of the previously defined TCII sublineages, constituting a new genotype designated as TCbat. Phylogenetic analyses demonstrated that TCbat indeed belongs to T. cruzi and not to other closely related bat trypanosomes of the subgenus Schizotrypanum, and that although separated by large genetic distances TO-tat is closest to lineage TCI. A genotyping method targeting ITS1 rDNA distinguished TCbat from established T. cruzi lineages, and from other Schizotrypanum species. In experimentally infected mice, TCbat lacked virulence and yielded loss parasitaemias. Isolates of TCbat presented distinctive morphological features and behaviour in triatomines. To date, TCbat genotype wall found only in bats from anthropic environments of Central and Southeast Brazil. Our findings indicate that the complexity of T. cruzi is larger than currently known, and confirmed bats as important reservoirs and potential source of T. cruzi infections to humans.

Phylogenetic analysis of Trypanosoma vivax supports the separation of South American/West African from East African isolates and a new T-vivax-like genotype infecting a nyala antelope from Mozambique

In this study, we addressed the phylogenetic and taxonomic relationships of Trypanosoma vivax and related trypanosomes nested in the subgenus Duttonella through combined morphological and phylogeographical analyses. We previously demonstrated that the clade T. vivax harbours a homogeneous clade comprising West African/South American isolates and the heterogeneous East African isolates. Herein we characterized a trypanosome isolated from a nyala antelope (Tragelaphus angasi) wild-caught in Mozambique (East Africa) and diagnosed as T. vivax-like based on biological, morphological and molecular data. Phylogenetic relationships, phylogeographical patterns and estimates of genetic divergence were based on SSU and ITS rDNA sequences of T. vivax from Brazil and Venezuela (South America), Nigeria (West Africa), and from T. vivax-like trypanosomes from Mozambique, Kenya and Tanzania (East Africa). Despite being well-supported within the T. vivax clade, the nyala trypanosome was highly divergent from all other T. vivax and T. vivax-like trypanosomes, even those from East Africa. Considering its host origin, morphological features, behaviour in experimentally infected goats, phylogenetic placement, and genetic divergence this isolate represents a new genotype of trypanosome closely phylogenetically related to T. vivax. This study corroborated the high complexity and the existence of distinct genotypes yet undescribed within the subgenus Duttonella.

GENOTYPE CHARACTERIZATION OF THE Haematobia irritans (DIPTERA: MUSCIDAE) FROM BRAZIL, DOMINICAN REPUBLIC AND COLOMBIA BASED ON RANDOMLY AMPLIFIED POLYMORPHIC DNA (RAPD) ANALYSIS

Blood-sucking flies are important parasites in animal production systems, especially regarding confinement conditions. Haematobia irritans, the horn fly, is one of the most troublesome species within bovine production systems, due to the intense stress imposed to the animals. H. irritans is one of the parasites of cattle that cause significant economic losses in many parts of the world, including South America. In the present work, Brazilian, Colombian and Dominican Republic populations of this species were studied by Random Amplified Polymorphic DNA(RAPD) to assess basically genetic variability between populations. Fifteen different decamer random primers were employed in the genomic DNA amplification, yielding 196 fragments in the three H. irritans populations. Among h. irritans samples, that from Colombia produced the smallest numbers of polymorphic hands. This high genetic homogeneity may be ascribed to its geographic origin, which causes high isolation, low gene flow, unlike the other American populations, from Brazil and Dominican Republic. Molecular marker fragments, which its produced exclusive bands, detected in every sample enabled the population origin to be characterized, but they are also potentially useful for further approaches such as the putative origin of Brazilian, Colombian and Dominican Republic populations of horn fly from South America. Similarity indices produced by chemo metric analysis showed the closest relationships between flies from Brazil and Dominican Republic, while flies from Colombia showed the greatest genotypic differentiation relative to the others populations.