27 research outputs found
Cost-effective analysis of different algorithms for the diagnosis of hepatitis C virus infection
Frequency and genotypic distribution of GB virus C (GBV-C) among Colombian population with Hepatitis B (HBV) or Hepatitis C (HCV) infection
<p>Abstract</p> <p>Background</p> <p>GB virus C (GBV-C) is an enveloped positive-sense ssRNA virus belonging to the <it>Flaviviridae </it>family. Studies on the genetic variability of the GBV-C reveals the existence of six genotypes: genotype 1 predominates in West Africa, genotype 2 in Europe and America, genotype 3 in Asia, genotype 4 in Southwest Asia, genotype 5 in South Africa and genotype 6 in Indonesia. The aim of this study was to determine the frequency and genotypic distribution of GBV-C in the Colombian population.</p> <p>Methods</p> <p>Two groups were analyzed: i) 408 Colombian blood donors infected with HCV (n = 250) and HBV (n = 158) from Bogotá and ii) 99 indigenous people with HBV infection from Leticia, Amazonas. A fragment of 344 bp from the 5' untranslated region (5' UTR) was amplified by nested RT PCR. Viral sequences were genotyped by phylogenetic analysis using reference sequences from each genotype obtained from GenBank (n = 160). Bayesian phylogenetic analyses were conducted using Markov chain Monte Carlo (MCMC) approach to obtain the MCC tree using BEAST v.1.5.3.</p> <p>Results</p> <p>Among blood donors, from 158 HBsAg positive samples, eight 5.06% (n = 8) were positive for GBV-C and from 250 anti-HCV positive samples, 3.2%(n = 8) were positive for GBV-C. Also, 7.7% (n = 7) GBV-C positive samples were found among indigenous people from Leticia. A phylogenetic analysis revealed the presence of the following GBV-C genotypes among blood donors: 2a (41.6%), 1 (33.3%), 3 (16.6%) and 2b (8.3%). All genotype 1 sequences were found in co-infection with HBV and 4/5 sequences genotype 2a were found in co-infection with HCV. All sequences from indigenous people from Leticia were classified as genotype 3. The presence of GBV-C infection was not correlated with the sex (p = 0.43), age (p = 0.38) or origin (p = 0.17).</p> <p>Conclusions</p> <p>It was found a high frequency of GBV-C genotype 1 and 2 in blood donors. The presence of genotype 3 in indigenous population was previously reported from Santa Marta region in Colombia and in native people from Venezuela and Bolivia. This fact may be correlated to the ancient movements of Asian people to South America a long time ago.</p
Characterization of a Peptide Domain within the GB Virus C NS5A Phosphoprotein that Inhibits HIV Replication
BACKGROUND:GBV-C infection is associated with prolonged survival in HIV-infected people and GBV-C inhibits HIV replication in co-infection models. Expression of the GBV-C nonstructural phosphoprotein 5A (NS5A) decreases surface levels of the HIV co-receptor CXCR4, induces the release of SDF-1 and inhibits HIV replication in Jurkat CD4+ T cell lines. METHODOLOGY/PRINCIPAL FINDINGS:Jurkat cell lines stably expressing NS5A protein and peptides were generated and HIV replication in these cell lines assessed. HIV replication was significantly inhibited in all cell lines expressing NS5A amino acids 152-165. Substitution of an either alanine or glycine for the serine at position 158 (S158A or S158G) resulted in a significant decrease in the HIV inhibitory effect. In contrast, substituting a phosphomimetic amino acid (glutamic acid; S158E) inhibited HIV as well as the parent peptide. HIV inhibition was associated with lower levels of surface expression of the HIV co-receptor CXCR4 and increased release of the CXCR4 ligand, SDF-1 compared to control cells. Incubation of CD4+ T cell lines with synthetic peptides containing amino acids 152-167 or the S158E mutant peptide prior to HIV infection resulted in HIV replication inhibition compared to control peptides. CONCLUSIONS/SIGNIFICANCE:Expression of GBV-C NS5A amino acids 152-165 are sufficient to inhibit HIV replication in vitro, and the serine at position 158 appears important for this effect through either phosphorylation or structural changes in this peptide. The addition of synthetic peptides containing 152-167 or the S158E substitution to Jurkat cells resulted in HIV replication inhibition in vitro. These data suggest that GBV-C peptides or a peptide mimetic may offer a novel, cellular-based approach to antiretroviral therapy
High prevalence and autochtonous transmission of human pegivirus (HPgV‐1) in blood donors in the extreme southern of Brazil
Clinical reactivation after liver transplantation with an unusual minor strain of hepatitis B virus in an occult carrier
Prevalence of GB virus C/hepatitis G virus among blood donors in north-eastern Brazil.
We tested 70 blood donors from Fortaleza (Ceara state, Brazil) for GB virus C/hepatitis G virus (GBV/HGV) infection by polymerase chain reaction and detection of antienvelope antibodies. Twenty-seven (38.6%) showed signs of an active or resolved infection. Sixty-four percent of those with indications of other blood-borne viral infections showed signs of GBV-C/HGV infection also
Prevalence of Hepatitis G Virus and Co-Infection with Hepatitis B Virus and Hepatitis C Virus Among Hemodialysis Patients in Ahvaz, Iran
Tonometers and infectious risk: myth or reality? Efficacy of different disinfection regimens on tonometer tips.
Purpose To evaluate the adequacy of
common disinfection regimens for disposable
tonometer tips and assess if disinfection of
reusable prisms or the use of disposable tips is
preferable.
Methods We used disposable tonometer tips,
using the same material and tip diameter of
standard Goldmann tonometer prism. Strains
of Pseudomonas aeruginosa, Staphylococcus
aureus, Bacillus subtilis and Candida albicans
were tested according to the European
standard guidelines for disinfectants test.
Antimicrobial effectiveness of the following
disinfection practices has been assessed:
dry wipe, Minuten wipes (Alpros), soaking
in 3% hydrogen peroxide, 0.5% benzalkonium
chloride, and 0.5% Pantasepts for 1, 5, and
15 min. All tests have been performed
three times and all conditions tested in
duplicate.
Results Dry wiping and 1 min soak in 3%
hydrogen peroxide were ineffective on all
microrganisms. Minuten wipes, 1 min soak in
0.5% benzalkonium chloride or 3% hydrogen
peroxide were ineffective on B. subtilis. 0.5%
Pantasepts soak was effective in 1 min for all
microrganisms tested, whereas 3% hydrogen
peroxide and 0.5% benzalkonium chloride
soaks were effective when performed for at
least 5 min. B. subtilis was the most resistant
organism to disinfectant regimes at 1 min time.
Conclusions Results of our study
demonstrate a relative disinfection efficacy for
the different evaluated regimens, provided
that correct exposure times are adopted for the
chosen disinfectants, a condition difficult to
ensure in a busy clinic setting. We conclude
that disposable prism tonometry provides a
safe alternative to Goldmann tonometry