Hepatitis B virus (HBV) genotypes E to J are understudied genotypes. Genotype E is found almost exclusively in West Africa. Genotypes F and H are found in America and are rare in other parts of the ...world. The distribution of genotype G is not completely known. Genotypes I and J are found in Asia and probably result from recombination events with other genotypes. The number of reported sequences for HBV genotypes E to J is small compared to other genotypes, which could impact phylogenetic and pairwise distance analyses. Genotype F is the most divergent of the HBV genotypes and is subdivided into six subgenotypes F1 to F6. Genotype E may be a recent genotype circulating almost exclusively in sub-Saharan Africa. Genotype J is a putative genotype originating from a single Japanese patient. The paucity of data from sub-Saharan Africa and Latin America is due to the under-representation of these regions in clinical and research cohorts. The purpose of this review is to highlight the need for further research on HBV genotypes E to J, which appear to be overlooked genotypes.
The Receptor Binding Domain (RBD) of SARS-CoV-2, the virus responsible for the COVID-19 pandemic, is the functional region of the viral Spike protein (S), which is involved in cell attachment to ...target cells. The virus has accumulated progressively mutations in its genome, particularly in the RBD region, many of them associated with immune evasion of the host neutralizing antibodies. Some of the viral lineages derived from this evolution have been classified as Variant of Interest (VOI) or Concern (VOC). The neutralizing capacity of a F(ab')2 preparation from sera of horses immunized with viral RBD was evaluated by lytic plaque reduction assay against different SARS-CoV-2 variants. A F(ab')2 preparation of a hyperimmune serum after nine immunizations with RBD exhibited a high titer of neutralizing antibodies against the ancestral-like strain (1/18,528). A reduction in the titer of the F(ab')2 preparation was observed against the different variants tested compared to the neutralizing activity against the ancestral-like strain. The highest reduction in the neutralization titer was observed for the Omicron VOC (4.7-fold), followed by the Mu VOI (2.6), Delta VOC (1.8-fold), and Gamma VOC (1.5). Even if a progressive reduction in the neutralizing antibodies titer against the different variants evaluated was observed, the serum still exhibited a neutralizing titer against the Mu VOI and the Omicron VOC (1/7113 and 1/3918, respectively), the evaluated strains most resistant to neutralization. Therefore, the preparation retained neutralizing activity against all the strains tested.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Introduction: Hepatitis C virus (HCV) displays high genetic variability, with seven genotypes and numerous subtypes. The determination of the viral type has been essential for the selection and ...timing of antiviral treatment. In Venezuela, HCV genotype 2 is relatively diverse, being particularly prevalent subtype 2j.
Objective: To evaluate the performance of methodologies for genotyping HCV, particularly for identification of subtype 2j.
Materials and methods: HCV genotype and subtype were determined by reverse hybridization technique (LiPA) and sequencing of the HCV 5’UTR and NS5B regions.
Results: A total of 65 samples from HCV-infected patients were analyzed. PCR amplifications of the 5’UTR region exhibited the highest sensitivity (100% vs 91% for LiPA and 77% for NS5B). Genotype determination, taking as reference test NS5B, showed 100% concordance with the other methods, and 67% and 59% for subtypes with 5´NC and LiPA, respectively. NS5B sequencing allowed the identification of subtypes 2j and 2s, which were not detected by the other methods. A specific LiPA pattern was not
observed for HCV subtype 2j.
Conclusion: Although being the methodology with lowest sensitivity for amplification of HCV RNA, sequencing NS5B region remains a powerful tool for correct discrimination of the different HCV subtypes, which is of epidemiological relevance.
Hepatitis B eradication: vaccine as a key player Pujol, Flor Helene; Toyé, Rayana Maryse; Loureiro, Carmen Luisa ...
American journal of translational research,
01/2023, Letnik:
15, Številka:
8
Journal Article
OBJECTIVEDespite the availability of a highly effective and safe vaccine against hepatitis B virus (HBV) infection for 40 years, still almost 300 million persons are estimated to be chronically ...infected by this virus worldwide. The World Health Organization (WHO) has proposed a plan for hepatitis elimination by 2030. However, several factors, such as the reduction and limitation in vaccination campaigns or vaccine hesitancy (VH) in some regions of the World, might have played a role in limiting the worldwide coverage of hepatitis B prophylaxis. This review aims to describe which factors, such as VH, may be hampering the WHO 2030 goal for hepatitis B eradication. METHODSThe review describes the development and characteristics of the HBV vaccine, from the first plasma-derived to the recombinant one. Eventual limitations in its effectiveness and particularly VH were reviewed. RESULTSThe apparent pitfalls of the HBV vaccine, such as long-term effectiveness, vaccine-escape mutants, and adverse effects, were proven not to be a concern for this vaccine. However, VH persists and was even intensified by the COVID-19 pandemic. CONCLUSIONSMany barriers still exist, such as vaccine availability, lack of awareness of the benefits of HBV vaccination, and VH. HBV VH seems to be eventually overcome in many settings with active education campaigns and information, stressing the importance of developing these strategies to achieve the 2030 goal of the WHO.
The Receptor Binding Domain (RBD) of SARS-CoV-2, the virus responsible for the COVID-19 pandemic, is the functional region of the viral Spike protein (S), which is involved in cell attachment to ...target cells. The virus has accumulated progressively mutations in its genome, particularly in the RBD region, many of them associated with immune evasion of the host neutralizing antibodies. Some of the viral lineages derived from this evolution have been classified as Variant of Interest (VOI) or Concern (VOC). The neutralizing capacity of a F(ab′)2 preparation from sera of horses immunized with viral RBD was evaluated by lytic plaque reduction assay against different SARS-CoV-2 variants. A F(ab′)2 preparation of a hyperimmune serum after nine immunizations with RBD exhibited a high titer of neutralizing antibodies against the ancestral-like strain (1/18,528). A reduction in the titer of the F(ab’)2 preparation was observed against the different variants tested compared to the neutralizing activity against the ancestral-like strain. The highest reduction in the neutralization titer was observed for the Omicron VOC (4.7-fold), followed by the Mu VOI (2.6), Delta VOC (1.8-fold), and Gamma VOC (1.5). Even if a progressive reduction in the neutralizing antibodies titer against the different variants evaluated was observed, the serum still exhibited a neutralizing titer against the Mu VOI and the Omicron VOC (1/7113 and 1/3918, respectively), the evaluated strains most resistant to neutralization. Therefore, the preparation retained neutralizing activity against all the strains tested.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
6.
HIV-1 and GBV-C co-infection in Venezuela Rodríguez, Anny Karely; Garzaro, Domingo José; Loureiro, Carmen Luisa ...
Journal of infection in developing countries,
2014-Jul-14, Letnik:
8, Številka:
7
Journal Article
Recenzirano
Odprti dostop
Co-infection with GB virus C (GBV-C) in patients infected with human immunodeficiency virus 1 (HIV-1) has been associated with prolonged survival. The aim of this study was to evaluate the prevalence ...of GBV-C infection among HIV-1-infected patients in Venezuela, and to determine the effects of the co-infection on the levels of relevant cytokines.
Plasma samples were collected from 270 HIV-1-seronegative and 255 HIV-1-seropositive individuals. GBV-C infection was determined by RT-PCR of the NS5 region and genotyped by sequence analysis of the 5´UTR region. HIV-1 strains were characterized by sequence analysis of pol, vif, env, and nef genes. Selected cytokines were evaluated by ELISA.
Ninety-seven of 525 (18.5%) plasma samples tested positive for GBV-C RNA. A significantly higher prevalence of GBV-C was found among HIV-1 patients compared to HIV-1-seronegative individuals (67/255, 26% versus 30/270, 11%; p < 0.001). Statistical difference was observed in the viral load between HIV-1+GBV-C+ and HIV-1+GBV-C- (p = 0.014), although no differences in CD4+ cell counts were found between both groups. TNFα concentration was higher in HIV-1+GBV-C- than in HIV-1+GBV-C+ patients (25.9 pg/mL versus 17.3 pg/mL; p = 0.02); RANTES expression levels were more variable in GBV-C co-infected patients and more frequently elevated in HIV-1 mono-infected patients compared to patients co-infected with GBV-C.
The previously observed beneficial effect of co-infection with HIV-1 and GBV-C on disease progression is complex and might be due in part to a change in the cytokine environment. More studies are required to understand the interaction between both viruses.
Estrés celular y SARS-CoV-2 Delgado, Mariangel; Rodríguez, Mariajose; Moros, Zoila ...
Salus (Universidad de Carabobo. Facultad de Ciencias de la Salud),
02/2022, Letnik:
25, Številka:
3
Journal Article
Odprti dostop
Introducción: El agente etiológico responsable de COVID-19, SARSCoV-2, es un virus ARN perteneciente a la familia Coronaviridae. Durante la replicación, los componentes virales interactúan con la ...maquinaria celular induciendo alteraciones en la fisiología celular, lo que contribuye a la patogénesis del virus. Método: Revisión bibliográfica en NCBI/Pubmed sobre estrés celular y SARS-CoV-2 Hallazgos de interpretación: Como respuesta a la infección, en la célula hospedadora se activan vías de señalización, cuyo principal objetivo es recuperar la homeostasis y de no lograrlo, inducir a la activación de la muerte celular. Entre las vías de señalización mejor caracterizadas, destacan las rutas de estrés celular como el estrés oxidativo, la UPR (Respuesta a proteínas no plegadas), y la autofagia, las cuales son evolutivamente bien conservadas y además están interconectadas entre sí. Hay fuerte evidencia teórica y experimental de diversas interacciones de algunos componentes de estas rutas con distintas proteínas virales de los coronavirus, y ya se han adelantado algunos estudios con SARS-CoV-2. En esta revisión, resaltamos algunas de las rutas celulares-virus que se han caracterizado hasta el momento.
Reflexiones finales: Aún queda mucho por entender de estas rutas y su relación con las infecciones virales; esto pudiera constituir un importante blanco para la investigación y desarrollo de terapias antivirales.
Introducción. El virus de la hepatitis C (HCV) presenta una gran variabilidad genética, con siete genotipos y numerosos subtipos. La determinación del tipo viral ha sido fundamental para la ...escogencia y la duración del tratamiento antiviral adecuado. En Venezuela, el genotipo 2 del HCV es relativamente diverso, siendo particularmente prevalente el subtipo 2j.Objetivo. Evaluar el desempeño de las metodologías para la determinación del genotipo del HCV, particularmente para la identificación del subtipo 2j.Materiales y métodos. Se determinaron el genotipo y el subtipo del HCV mediante la técnica de hibridación inversa LiPA (Line Probe Assay) y secuenciación de las regiones genómicas 5’NC y NS5B del virus.Resultados. En 65 muestras analizadas, la metodología basada en la amplificación de la región 5’NC mostró mayor sensibilidad (100 %), en comparación con la técnica LiPA (91 %) y la secuenciación de la región NS5B (77 %). La determinación de genotipo, tomando como método de referencia la secuenciación de NS5B, mostró un alto grado de concordancia para la secuenciación de la región 5´NC y la hibridación inversa LiPA, con 100 % en la asignación de genotipos, comparado con 70 % y 66 % para los subtipos, respectivamente. La secuenciación de la región NS5B permitió identificar los subtipos 2j y 2s, los cuales no fueron detectados por las otras metodologías. No se observó un patrón característico para las muestras subtipo 2j en la hibridación inversa LiPA.Conclusión. Aunque es la metodología con menor sensibilidad, la secuenciación de la región NS5B es una herramienta poderosa para la correcta discriminación de los distintos subtipos circulantes del HCV, lo cual reviste importancia epidemiológica.
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