IHMT

Instituto de Higiene e Medicina Tropical

Home / Archives for Piedade J

Piedade J

Novel multiregion hybridization assay for the identification of the most prevalent genetic forms of the human immunodeficiency virus type 1 circulating in Portugal

The most efficient method for HIV-1 genetic characterization involves full-genome sequencing, but the associated costs, technical features, and low throughput preclude it from being routinely used for the analysis of large numbers of viral strains. Multiregion hybridization assays (MHA) represent an alternative for a consistent genetic analysis of large numbers of viral strains. Classically, MHA rely on the amplification by real-time PCR of several regions scattered along the HIV-1 genome, and on their characterization with clade-specific TaqMan probes (also known as hydrolysis probes).
Ler mais

Characterization of an insect-specific flavivirus (OCFVPT) co-isolated from Ochlerotatus caspius collected in southern Portugal along with a putative new Negev-like virus

We describe the isolation and characterization of an insect-specific flavivirus (ISF) from Ochlerotatus caspius (Pallas, 1771) mosquitoes collected in southern Portugal. The RNA genome of this virus, tentatively designated OCFVPT, for O. caspius flavivirus from Portugal, encodes a polyprotein showing all the features expected for a flavivirus. As frequently observed for ISF, the viral genomes seems to encode a putative Fairly Interesting Flavivirus ORF (FIFO)-like product, the synthesis of which would occur as a result of a -1 translation frameshift event. OCFVPT was isolated in the C6/36 Stegomyia albopicta (= Aedes albopictus) cell line where it replicates rapidly, but failed to replicate in Vero cells in common with other ISFs.
Ler mais

A new genotype 2 subcluster identified among GBV-C strains circulating in the Lisbon metropolitan area of Portugal

The rate of infection by the GBV-C virus was investigated in a group of 214 individuals at high risk of infection with parenterally transmitted viruses, and all living in the Lisbon metropolitan area (Portugal). RNA was extracted from plasma samples, and a fragment of the 5′-UTR was amplified by RT-PCR, disclosing a high prevalence of infection (40.7%).
Ler mais

A divergent insect-specific flavivirus that causes overt cytopathic effect in a mosquito cell-line

This work reports the initial characterization, including near full-length sequence analysis, of an ISF which seems to form a divergent lineage within the ISF radiation, as indicated by phylogenetic analysis based on ac multiple sequence alignment of the NS5 flavivirus coding sequence.
Ler mais

A new cloning system based on the OprI lipoprotein for the production of recombinant bacterial cell wall-derived immunogenic formulations.

The conjugation of antigens with ligands of pattern recognition receptors (PRR) is emerging as a promising strategy for the modulation of specific immunity. Here, we describe a new Escherichia coli system for the cloning and expression of heterologous antigens in fusion with the OprI lipoprotein, a TLR ligand from the Pseudomonas aeruginosa outer membrane (OM).
Ler mais

GB virus C (GBV-C) evolutionary patterns revealed by analyses of reference genomes, E2 and NS5B sequences amplified from viral strains circulating in the Lisbon area (Portugal).

GBV-C is a non-pathogenic virus that is largely dispersed in different human populations. The phylogenetic analysis of the 5′-untranslated region (5’UTR) of the GBV-C genome has led to the segregation of viral strains into six genotypes, but incongruent results are frequently obtained depending on the genome region analyzed. In this report, different phylogenetic approaches and multivariate statistics were combined to disclose evolutionary patterns that contribute to shape GBV-C evolution.
Ler mais

Hepatitis C virus subtypes circulating among intravenous drug users in Lisbon, Portugal.

Hepatitis C virus (HCV) infects 2-3% of the world population and intravenous drug consumption is the leading cause of transmission in industrialized countries. The unavailability of data on the molecular epidemiology of HCV infection in Portugal prompted the study of HCV subtypes circulating among intravenous drug users residing in the Lisbon metropolitan area and sampled about 10 years apart (1998-2000 and 2008-2009).
Ler mais

Genetic characterization of an insect-specific flavivirus isolated from Culex theileri mosquitoes collected in southern Portugal.

We describe the full genetic characterization of an insect-specific flavivirus (ISF) from Culex theileri (Theobald) mosquitoes collected in Portugal. This represents the first isolation and full characterization of an ISF from Portuguese mosquitoes. The virus, designated CTFV, for Culex theileri flavivirus, was isolated in the C6/36 Stegomyia albopicta (=Aedes albopictus) cell line, and failed to replicate in vertebrate (Vero) cells in common with other ISFs.
Ler mais

High rate of detection of G8P 6 rotavirus in children with acute gastroenteritis in Sao Tome, and Principe

The burden of rotavirus infections greatly affects the low-income African countries. In the absence of epidemiological data on pediatric diarrhea in São Tomé and Príncipe (STP), a study was conducted from August to December 2011.
Ler mais

Negeviruses found in multiple species of mosquitoes from southern Portugal: Isolation, genetic diversity, and replication in insect cell culture

In this report, an RT-PCR approach based on the use of degenerate primers allowed the identification of negeviruses in four different species of mosquitoes (Ochlerotatus caspius, Culex pipiens, Cx. theileri and Cx. univittatus) collected in southern Portugal. The genomes of two of these viruses, sequenced to full completion, were shown to encode all the proteins encoded by previously described negeviruses
Ler mais