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1.
Ann Hepatol ; 28(1): 100770, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36220615

RESUMO

INTRODUCTION AND OBJECTIVES: Chronic hepatitis D infection contributes substantially to the progression of chronic liver disease, especially in most low and middle-income countries, where hepatitis B virus-related chronic liver disease is endemic. Therefore, this study aimed to determine the magnitude and genotype of hepatitis delta virus (HDV) among patients with chronic hepatitis B (CHB)-related liver diseases in Ethiopia. PATIENTS AND METHODS: In this cross-sectional study, 323 known HBsAg positive individuals comprising 220 patients with CHB-related liver diseases [121 advanced liver diseases (hepatocellular carcinoma /HCC/ and non-HCC) and 99 chronic hepatitis (CH)], and 103 symptomless blood donors (BD) were enrolled. An ELISA kit was employed to determine HDV infection, and quantitative real-time PCR was used to detect HDV RNA. In addition, a non-coding genomic RNA region was sequenced for genotyping and phylogenetic analysis. RESULTS: Irrespective of the stage of liver disease, the overall magnitude of HDV was 7.7% (25/323). The frequency of anti-HDV increases with the severity of liver disease, 1.9%, 4%, 10%, and 21.3% among BD, CH, non-HCC, and HCC patients, respectively. HDV RNA has been detected in 1.54 %(5/323) cases with a mean viral load of 4,010,360 IU/ml. All isolates were found to be HDV genotype 1. CONCLUSIONS: The magnitude of HDV infection increased with the severity of liver disease, indicating HDV infection is more common among patients with CHB-related liver diseases in Ethiopia.


Assuntos
Carcinoma Hepatocelular , Coinfecção , Hepatite B Crônica , Hepatite B , Neoplasias Hepáticas , Humanos , Vírus Delta da Hepatite/genética , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/epidemiologia , Etiópia/epidemiologia , Filogenia , Estudos Transversais , Vírus da Hepatite B , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/genética , Genótipo , RNA Viral/genética , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/genética , Hepatite B/epidemiologia , Antígenos de Superfície da Hepatite B , Coinfecção/epidemiologia
2.
Anal Chem ; 93(4): 2627-2634, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33471510

RESUMO

In March 2020, the SARS-CoV-2 virus outbreak was declared as a world pandemic by the World Health Organization (WHO). The only measures for controlling the outbreak are testing and isolation of infected cases. Molecular real-time polymerase chain reaction (PCR) assays are very sensitive but require highly equipped laboratories and well-trained personnel. In this study, a rapid point-of-need detection method was developed to detect the RNA-dependent RNA polymerase (RdRP), envelope protein (E), and nucleocapsid protein (N) genes of SARS-CoV-2 based on the reverse transcription recombinase polymerase amplification (RT-RPA) assay. RdRP, E, and N RT-RPA assays required approximately 15 min to amplify 2, 15, and 15 RNA molecules of molecular standard/reaction, respectively. RdRP and E RT-RPA assays detected SARS-CoV-1 and 2 genomic RNA, whereas the N RT-RPA assay identified only SARS-CoV-2 RNA. All established assays did not cross-react with nucleic acids of other respiratory pathogens. The RT-RPA assay's clinical sensitivity and specificity in comparison to real-time RT-PCR (n = 36) were 94 and 100% for RdRP; 65 and 77% for E; and 83 and 94% for the N RT-RPA assay. The assays were deployed to the field, where the RdRP RT-RPA assays confirmed to produce the most accurate results in three different laboratories in Africa (n = 89). The RPA assays were run in a mobile suitcase laboratory to facilitate the deployment at point of need. The assays can contribute to speed up the control measures as well as assist in the detection of COVID-19 cases in low-resource settings.


Assuntos
COVID-19/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Recombinases/metabolismo , SARS-CoV-2/isolamento & purificação , COVID-19/virologia , Humanos , Sensibilidade e Especificidade
3.
Cytometry A ; 99(8): 774-783, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33280233

RESUMO

Cytomegalovirus (CMV)-specific T cells expand with CMV reactivation and are probably prerequisite for control and protection. Given the critical role STAT5A phosphorylation (pSTAT5A) in T cell proliferation, this study presents a simple and sensitive flow cytometric-based pSTAT5A assay to quickly identify CMV-specific T cell proliferation. We determined pSTAT5A in T cells treated with CMV-specific peptide mix (pp65 + IE1 peptides) from 20 healthy adult subjects and three immunodeficient patients with CARMIL-2 mutation. After stimulation, the percentage of pSTAT5A+ T cells in CMV-seropositive (CMV+ ) subjects significantly increased from 3.0% ± 1.9% (unstimulated) to 11.4% ± 5.9% (stimulated) for 24 h. After 7 days of stimulation, the percentage of expanded T cells amounted to 26% ± 17.2%. Conversely, the percentage of pSTAT5A+ T cells and T cell proliferation from CMV-seronegative (CMV- ) subjects hardly changed (from 3.0% ± 1.3% to 3.7% ± 1.8% and from 4.3% ± 2.1% to 5.7% ± 1.7%, respectively). We analyzed the correlation between the percentage of pSTAT5A+ T cells versus (1) CMV-IgG concentrations versus (2) the percentage of expanded T cells and versus (3) the percentage of initial CMV-specific T cells. In immunodeficient patients with CARMIL-2 mutation, CMV-specific pSTAT5A and T cell proliferation were completely deficient. In conclusion, flow cytometric-based pSTAT5A assay represents an appropriate tool to quickly identify CMV-specific T cell proliferation and helps to understand dysfunctions in controlling other pathogens. Flow cytometric-based pSTAT5A assay may be a useful test in clinical practice and merits further validation in large studies.


Assuntos
Infecções por Citomegalovirus , Citomegalovirus , Linfócitos T CD8-Positivos , Humanos , Fosfoproteínas , Fosforilação , Fator de Transcrição STAT5 , Linfócitos T , Proteínas da Matriz Viral
4.
J Med Virol ; 92(12): 3007-3015, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32170868

RESUMO

Enteroviruses (EVs) and human parechoviruses (HPeVs) infections are associated with various forms of disease, including gastroenteritis. As information on the molecular epidemiology of these viruses is limited in Ethiopia, the genetic diversity of EV and HPeV was investigated in the Northwestern part of the country. Of the total 450 stool samples obtained from infants and young children with diarrhea, 157 (34.9%) were positive for EV and 49 (10.9%) for HPeV RNA when tested by real-time reverse transcription polymerase chain reaction. Genotyping was performed by sequencing of the EV VP1 gene and the HPeV VP3/VP1 gene, respectively. Genotyping of EV was successful in 118 samples. Thereof, 82 (69.5%) belonged to non-polio EVs as a broad range of genotypes within species C, B, and A. Sabin polioviruses were found in 36 cases. HPeV sequences were also heterogeneous with a relative dominance of genotype 3. In conclusion, diverse EV and HPeV genotypes were found cocirculating in Northwest Ethiopia. The findings highlight the importance of continuous surveillance of these viruses in Ethiopia.

5.
Euro Surveill ; 25(46)2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33213686

RESUMO

Following a distinct summer heat wave, nine autochthonous cases of West Nile fever and West Nile neuroinvasive disease, including one fatality, were observed in Leipzig, Germany, in August and September 2020. Phylogenetic analysis demonstrated close relationships in viruses from humans, animals and mosquitos in eastern Germany, obtained during the preceding 2 years. The described large cluster of autochthonous West Nile virus infections in Germany indicates endemic seasonal circulation of lineage 2 viruses in the area.


Assuntos
Surtos de Doenças , Febre do Nilo Ocidental , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Alemanha/epidemiologia , Humanos , Pessoa de Meia-Idade , Filogenia , Febre do Nilo Ocidental/epidemiologia , Vírus do Nilo Ocidental/genética , Adulto Jovem
6.
J Virol ; 92(17)2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29950419

RESUMO

The flexible regulation of cellular metabolic pathways enables cellular adaptation to changes in energy demand under conditions of stress such as posed by a virus infection. To analyze such an impact on cellular metabolism, rubella virus (RV) was used in this study. RV replication under selected substrate supplementation with glucose, pyruvate, and glutamine as essential nutrients for mammalian cells revealed its requirement for glutamine. The assessment of the mitochondrial respiratory (based on the oxygen consumption rate) and glycolytic (based on the extracellular acidification rate) rate and capacity by respective stress tests through Seahorse technology enabled determination of the bioenergetic phenotype of RV-infected cells. Irrespective of the cellular metabolic background, RV infection induced a shift of the bioenergetic state of epithelial cells (Vero and A549) and human umbilical vein endothelial cells to a higher oxidative and glycolytic level. Interestingly there was a RV strain-specific, but genotype-independent demand for glutamine to induce a significant increase in metabolic activity. While glutaminolysis appeared to be rather negligible for RV replication, glutamine could serve as donor of its amide nitrogen in biosynthesis pathways for important metabolites. This study suggests that the capacity of RVs to induce metabolic alterations could evolve differently during natural infection. Thus, changes in cellular bioenergetics represent an important component of virus-host interactions and could complement our understanding of the viral preference for a distinct host cell population.IMPORTANCE RV pathologies, especially during embryonal development, could be connected with its impact on mitochondrial metabolism. With bioenergetic phenotyping we pursued a rather novel approach in virology. For the first time it was shown that a virus infection could shift the bioenergetics of its infected host cell to a higher energetic state. Notably, the capacity to induce such alterations varied among different RV isolates. Thus, our data add viral adaptation of cellular metabolic activity to its specific needs as a novel aspect to virus-host evolution. In addition, this study emphasizes the implementation of different viral strains in the study of virus-host interactions and the use of bioenergetic phenotyping of infected cells as a biomarker for virus-induced pathological alterations.


Assuntos
Metabolismo Energético , Glutamina/metabolismo , Glicólise/efeitos dos fármacos , Consumo de Oxigênio/fisiologia , Vírus da Rubéola/metabolismo , Células A549 , Células Endoteliais/metabolismo , Células Endoteliais/virologia , Glucose/metabolismo , Glucose/farmacologia , Glutamina/farmacologia , Homeostase , Humanos , Cinurenina/metabolismo , Redes e Vias Metabólicas/efeitos dos fármacos , Mitocôndrias/metabolismo , Nucleotídeos/biossíntese , Oxirredução , Estresse Oxidativo , Consumo de Oxigênio/efeitos dos fármacos , Fenótipo , Ácido Pirúvico/metabolismo , Ácido Pirúvico/farmacologia , Replicação Viral/efeitos dos fármacos
7.
J Virol ; 92(6)2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29263261

RESUMO

In previous studies, we showed that the cellular RNA-binding protein AUF1 supports the replication process of the flavivirus West Nile virus. Here we demonstrate that the protein also enables effective proliferation of dengue virus and Zika virus, indicating that AUF1 is a general flavivirus host factor. Further studies demonstrated that the AUF1 isoform p45 significantly stimulates the initiation of viral RNA replication and that the protein's RNA chaperone activity enhances the interactions of the viral 5'UAR and 3'UAR genome cyclization sequences. Most interestingly, we observed that AUF1 p45 destabilizes not only the 3'-terminal stem-loop (3'SL) but also 5'-terminal stem-loop B (SLB) of the viral genome. RNA structure analyses revealed that AUF1 p45 increases the accessibility of defined nucleotides within the 3'SL and SLB and, in this way, exposes both UAR cyclization elements. Conversely, AUF1 p45 does not modulate the fold of stem-loop A (SLA) at the immediate genomic 5' end, which is proposed to function as a promoter of the viral RNA-dependent RNA polymerase (RdRp). These findings suggest that AUF1 p45, by destabilizing specific stem-loop structures within the 5' and 3' ends of the flaviviral genome, assists genome cyclization and concurrently enables the RdRp to initiate RNA synthesis. Our study thus highlights the role of a cellular RNA-binding protein inducing a flaviviral RNA switch that is crucial for viral replication.IMPORTANCE The genus Flavivirus within the Flaviviridae family includes important human pathogens, such as dengue, West Nile, and Zika viruses. The initiation of replication of the flaviviral RNA genome requires a transformation from a linear to a cyclized form. This involves considerable structural reorganization of several RNA motifs at the genomic 5' and 3' ends. Specifically, it needs a melting of stem structures to expose complementary 5' and 3' cyclization elements to enable their annealing during cyclization. Here we show that a cellular RNA chaperone, AUF1 p45, which supports the replication of all three aforementioned flaviviruses, specifically rearranges stem structures at both ends of the viral genome and in this way permits 5'-3' interactions of cyclization elements. Thus, AUF1 p45 triggers the RNA switch in the flaviviral genome that is crucial for viral replication. These findings represent an important example of how cellular (host) factors promote the propagation of RNA viruses.


Assuntos
Flavivirus/fisiologia , Genoma Viral , Ribonucleoproteínas Nucleares Heterogêneas Grupo D/metabolismo , Conformação de Ácido Nucleico , RNA Viral/metabolismo , Replicação Viral/fisiologia , Ribonucleoproteína Nuclear Heterogênea D0 , Ribonucleoproteínas Nucleares Heterogêneas Grupo D/química , Ribonucleoproteínas Nucleares Heterogêneas Grupo D/genética , Humanos , RNA Viral/química , RNA Viral/genética , RNA Polimerase Dependente de RNA/química , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismo
8.
Arch Virol ; 164(12): 2985-2993, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31570995

RESUMO

Human adenovirus (HAdV) and human astrovirus (HAstV) are common causes of gastroenteritis. Data on the prevalence and diversity of enteric viruses are important for control and preventive measures. However, epidemiological information regarding HAdV and HAstV infections in Ethiopia are limited. Fecal specimens were collected from 450 outpatient diarrheic infants and young children in Gondar and Bahir Dar from November 2015 to April 2016. Socio-demographic information was recorded. All fecal specimens were screened for the presence of HAdV and classical HAstV using PCR. Genotyping was performed by sequencing and phylogenetic analysis. Human HAdV and HAstV were detected in 144 (32%) and 16 (3.6%) of the children, respectively. Overall, 182 different adenovirus genotypes were detected, including mixed infections. Species F adenoviruses (HAdV-40, HAdV-41) were less common than other adenoviruses (HAdV-1, -2, -3, -5,-12, -16, -31, species D types) with a frequency of 32 versus 150, respectively. The HAstV genotypes were classified as HAstV-8 (n = 10), HAstV-1 (n = 3), HAstV-2 (n = 3), and HAstV-3 (n = 1). HAstV was detected only in Gondar. Thirty-eight coinfections HAdV and one HAstV coinfections were detected. There was no significant difference in the detection rate of HAdV and HAstV between boys and girls. The detection rates also did not differ between children from rural and urban areas. Children under 6 months of age, were less often infected with both viruses. These findings suggest that HAdV and HAstV are common in children with diarrhea in Ethiopia.


Assuntos
Infecções por Adenoviridae/virologia , Adenovírus Humanos/genética , Infecções por Astroviridae/virologia , Gastroenterite/virologia , Mamastrovirus/genética , Doença Aguda/epidemiologia , Infecções por Adenoviridae/epidemiologia , Adenovírus Humanos/classificação , Adenovírus Humanos/isolamento & purificação , Adolescente , Adulto , Infecções por Astroviridae/epidemiologia , Criança , Pré-Escolar , Etiópia/epidemiologia , Feminino , Gastroenterite/epidemiologia , Variação Genética , Genótipo , Humanos , Lactente , Masculino , Mamastrovirus/classificação , Mamastrovirus/isolamento & purificação , Pessoa de Meia-Idade , Filogenia , Adulto Jovem
9.
RNA ; 22(10): 1574-91, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27520967

RESUMO

A prerequisite for the intracellular replication process of the Flavivirus West Nile virus (WNV) is the cyclization of the viral RNA genome, which enables the viral replicase to initiate RNA synthesis. Our earlier studies indicated that the p45 isoform of the cellular AU-rich element binding protein 1 (AUF1) has an RNA chaperone activity, which supports RNA cyclization and viral RNA synthesis by destabilizing a stem structure at the WNV RNA's 3'-end. Here we show that in mammalian cells, AUF1 p45 is consistently modified by arginine methylation of its C terminus. By a combination of different experimental approaches, we can demonstrate that the methyltransferase PRMT1 is necessary and sufficient for AUF1 p45 methylation and that PRMT1 is required for efficient WNV replication. Interestingly, in comparison to the nonmethylated AUF1 p45, the methylated AUF1 p45(aDMA) exhibits a significantly increased affinity to the WNV RNA termini. Further data also revealed that the RNA chaperone activity of AUF1 p45(aDMA) is improved and the methylated protein stimulates viral RNA synthesis considerably more efficiently than the nonmethylated AUF1 p45. In addition to its destabilizing RNA chaperone activity, we identified an RNA annealing activity of AUF1 p45, which is not affected by methylation. Arginine methylation of AUF1 p45 thus represents a specific determinant of its RNA chaperone activity while functioning as a WNV host factor. Our data suggest that the methylation modifies the conformation of AUF1 p45 and in this way affects its RNA binding and restructuring activities.


Assuntos
Arginina/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas Grupo D/metabolismo , Processamento de Proteína Pós-Traducional , RNA Viral/genética , Regiões 3' não Traduzidas , Linhagem Celular Tumoral , Ribonucleoproteína Nuclear Heterogênea D0 , Ribonucleoproteínas Nucleares Heterogêneas Grupo D/genética , Humanos , Metilação , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , RNA Viral/metabolismo , Proteínas Repressoras/metabolismo , Replicação Viral , Vírus do Nilo Ocidental/genética , Vírus do Nilo Ocidental/fisiologia
10.
J Gen Virol ; 98(12): 3037-3045, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29095687

RESUMO

Species D is the largest of the seven species of human mastadenoviruses (HAdV), but few of its multiple types are associated with asevere disease, e.g. epidemic keratoconjunctivitis. Many other types are hardly ever associated with significant diseases in immunocompetent patients, but have been isolated from the diarrhoeal faeces of terminal AIDS patients suggesting their role as opportunistic pathogens. Three novel HAdV-D strains were isolated from the faeces of three immunocompromised adult patients (clinical diagnoses: lymphoma, myelodysplastic syndrome and AIDS CDC3B, respectively). These strains were not typeable by imputed serology of the hexon and fibre gene and therefore complete genomic sequences were generated by next-generation sequencing (NGS). All three strains were multiple recombinants and fulfilled the criteria for designation as types 73, 74 and 75 with the penton/hexon/fibre genotype codes P67H45F27, P70H74F51 and P75H26F29, respectively. A novel genomic backbone and also a novel hexon neutralization epitope sequence were discovered in type 74, and a novel penton sequence in type 75. At the complete genome level, types 73, 74 and 75 were closely related neither to each other nor to type 70, which was previously isolated in the same region. However, these four HAdV-D types were closely related to each other in single genes and gene regions, e.g. penton, E1 and E4 due to recombination events in their phylogeny. In conclusion, regional co-circulation of opportunistic HAdV-D types facilitated co- and super-infections, which are essential for homologous recombination, and thus resulted in the evolution of novel genotypes by lateral gene transfer.

12.
J Clin Microbiol ; 54(1): 142-7, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26560532

RESUMO

Norovirus is the most common cause of sporadic gastroenteritis and outbreaks worldwide. The rapid identification of norovirus has important implications for infection prevention measures and may reduce the need for additional diagnostic testing. The Xpert Norovirus assay recently received FDA clearance for the detection and differentiation of norovirus genogroups I and II (GI and GII), which account for the vast majority of infections. In this study, we evaluated the performance of the Xpert Norovirus assay with both fresh, prospectively collected (n = 914) and frozen, archived (n = 489) fecal specimens. A Centers for Disease Control and Prevention (CDC) composite reference method was used as the gold standard for comparison. For both prospective and frozen specimens, the Xpert Norovirus assay showed positive percent agreement (PPA) and negative percent agreement (NPA) values of 98.3% and 98.1% for GI and of 99.4% and 98.2% for GII, respectively. Norovirus prevalence in the prospective specimens (collected from March to May of 2014) was 9.9% (n = 90), with the majority of positives caused by genogroup II (82%, n = 74). The positive predictive value (PPV) of the Xpert Norovirus assay was 75% for GI-positive specimens, whereas it was 86.5% for GII-positive specimens. The negative predictive values (NPV) for GI and GII were 100% and 99.9%, respectively.


Assuntos
Infecções por Caliciviridae/diagnóstico , Fezes/virologia , Genótipo , Técnicas de Diagnóstico Molecular/métodos , Norovirus/classificação , Norovirus/isolamento & purificação , Virologia/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções por Caliciviridae/virologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Norovirus/genética , Valor Preditivo dos Testes , Estudos Prospectivos , Adulto Jovem
13.
Clin Oral Investig ; 20(1): 193-7, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26411858

RESUMO

OBJECTIVES: Co-occurrence of oral lichen planus (OLP) and chronic hepatitis C virus (HCV) infection suggests a strong association, but the relation between mucocutaneus, autoimmune lichen planus and HCV infection remains unclear. In areas with higher prevalence of HCV infection in general population, like Japan and southern Europe, 20 to 40 % of patients with OLP test positive for anti-HCV antibodies, whereas in German populations, a co-occurrence of 4.2 to 16 % was reported. MATERIAL AND METHODS: We screened 143 patients with histopathologically proven OLP for prevalence of anti-HCV antibodies. Additionally, we examined 51 anti-HCV-positive subjects with current or past HCV infection for clinical symptoms of OLP. In all patients, confirmatory diagnosis was made by the detection of HCV RNA via reverse transcription-polymerase chain reaction (RT-PCR). A randomized control group comprised 109 blood sera samples of patients without any characteristics of OLP. RESULTS: The results of all patients showed no co-occurrence in either cohort. CONCLUSION: In conclusion, no association between oral lichen planus and chronic HCV infection in our study population was found. CLINICAL RELEVANCE: Anti-HCV antibody screening in patients with confirmed oral lichen planus is not indicated routinely in central Germany.


Assuntos
Hepatite C/epidemiologia , Líquen Plano Bucal/epidemiologia , Estudos Transversais , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Reação em Cadeia da Polimerase em Tempo Real
14.
J Virol ; 88(19): 11586-99, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25078689

RESUMO

UNLABELLED: A central aspect of current virology is to define the function of cellular proteins (host factors) that support the viral multiplication process. This study aimed at characterizing cellular proteins that assist the RNA replication process of the prevalent human pathogen West Nile virus (WNV). Using in vitro and cell-based approaches, we defined the p45 isoform of AU-rich element RNA-binding protein 1 (AUF1) as a host factor that enables efficient WNV replication. It was demonstrated that AUF1 p45 has an RNA chaperone activity, which aids the structural rearrangement and cyclization of the WNV RNA that is required by the viral replicase to initiate RNA replication. The obtained data suggest the RNA chaperone activity of AUF1 p45 is an important determinant of the WNV life cycle. IMPORTANCE: In this study, we identified a cellular protein, AUF1 (also known as heterogeneous ribonucleoprotein D [hnRNPD]), acting as a helper (host factor) of the multiplication process of the important human pathogen West Nile virus. Several different variants of AUF1 exist in the cell, and one variant, AUF1 p45, was shown to support viral replication most significantly. Interestingly, we obtained a set of experimental data indicating that a main function of AUF1 p45 is to modify and thus prepare the West Nile virus genome in such a way that the viral enzyme that generates progeny genomes is empowered to do this considerably more efficiently than in the absence of the host factor. The capability of AUF1 p45 to rearrange the West Nile virus genome was thus identified to be an important aspect of a West Nile virus infection.


Assuntos
Regulação Viral da Expressão Gênica , Genoma Viral , Ribonucleoproteínas Nucleares Heterogêneas Grupo D/genética , Chaperonas Moleculares/genética , RNA Viral/genética , Vírus do Nilo Ocidental/genética , Sítios de Ligação , Linhagem Celular Tumoral , Hepatócitos/metabolismo , Hepatócitos/virologia , Ribonucleoproteína Nuclear Heterogênea D0 , Ribonucleoproteínas Nucleares Heterogêneas Grupo D/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Chaperonas Moleculares/metabolismo , Ligação Proteica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA/química , RNA/genética , RNA/metabolismo , RNA Circular , RNA Viral/química , RNA Viral/metabolismo , Replicação Viral , Vírus do Nilo Ocidental/metabolismo
15.
J Med Virol ; 87(6): 978-84, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25649964

RESUMO

Antiretroviral drug resistance is a major challenge for management and control of HIV-1 infection worldwide and particularly in resource limited countries. The frequency of primary drug resistance mutations (DRMs) and of naturally occurring polymorphisms was determined in 83 antiretroviral treatment (ART) naïve Ethiopian individuals infected with HIV-1, consecutively enrolled in 2010. In all individuals HIV-1C was found. The median (interquartile range) of CD4(+) T-cell count and viral load were 100 (49-201) cells/µl and 44,640 (12,553-134,664) copies/ml, respectively. Protease (PR) and reverse transcriptase (RT) genes of HIV-1 RNA were amplified and sequenced. The proportion of primary DRM to any drug class, using the World Health Organization mutation lists, was 7.2% (6/83), thus exceeding the WHO threshold limit of 5%. Three individuals (3.6%) had non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations, two individuals (2.4%) had protease inhibitor mutations, and one (1.2%) had mutations associated with two drug classes (nucleoside reverse transcriptase inhibitor and NNRTI). In addition, the frequency of polymorphisms in the PR and RT genes was higher compared with previous studies in Ethiopian as well as worldwide isolates. Hence, genotypic drug resistance testing as part of routine management of individuals seems reasonable even in resource limited countries prior to treatment in order to allow proper choice of ART.


Assuntos
Fármacos Anti-HIV/farmacologia , Farmacorresistência Viral/genética , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Mutação , Adulto , Contagem de Linfócito CD4 , Etiópia , Feminino , Genótipo , Protease de HIV/genética , Inibidores da Protease de HIV/farmacologia , Transcriptase Reversa do HIV/genética , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Polimorfismo Genético , Inibidores da Transcriptase Reversa/farmacologia , Fatores de Risco , Carga Viral , Adulto Jovem
16.
J Neurovirol ; 19(5): 461-70, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23996691

RESUMO

Acute measles may lead in rare instances to the chronic progressive central nervous system disease process subacute sclerosing panencephalitis (SSPE). SSPE results from a persistent measles virus (MV) infection with incomplete virus replication involving the entire human brain. The experimental encephalitis model in Lewis rats was used to define affected cell populations after infection with the neurotropic MV strain CAM/RB. Distribution patterns of MV were analysed by appropriate cell markers in the brain sections of infected animals employing multiple immunofluorescence labelling and confocal laser scanning microscopy. MV was detected in neurones but not in astrocytes, oligodendrocytes, microglia, and endothelial cells. GABAergic and glutamatergic neurons displayed MV antigen whereas cholinergic and catecholaminergic neurons appeared devoid of MV immunoreactivity. Mapping of the rat brain has revealed MV-infected neurones predominantly in motor, somatosensory, auditory, and visual cortices as well as in the basal ganglia and thalamic nuclei of infected rats. The results indicate that MV apparently disseminates via GABAergic and glutaminergic neurones and their processes. The tightly restricted viral distribution pattern is consistent with both inefficient immune clearance from infected neurones and with the observed disease symptoms.


Assuntos
Encéfalo/patologia , Vírus do Sarampo/fisiologia , Sarampo/patologia , Neurônios/patologia , Panencefalite Esclerosante Subaguda/patologia , Animais , Animais Recém-Nascidos , Astrócitos/patologia , Biomarcadores/análise , Encéfalo/virologia , Células Endoteliais/patologia , Imunofluorescência , Humanos , Sarampo/virologia , Vírus do Sarampo/patogenicidade , Microglia/patologia , Neurônios/virologia , Oligodendroglia/patologia , Ratos , Ratos Endogâmicos Lew , Panencefalite Esclerosante Subaguda/virologia , Replicação Viral
17.
Infect Agent Cancer ; 18(1): 4, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36703179

RESUMO

BACKGROUND: Human papillomavirus (HPV) genotypes differ by geographic location. With the advent of HPV vaccination and HPV-based cervical screening tests in Ethiopia, a nationwide dataset on the genotype distribution of HPV among women has paramount importance in the fight against cervical cancer. However, there is limited data in this regard in the northwest part of the country. Therefore, this study aimed to identify the genotype distribution of high-risk HPVs among women presenting with cervical abnormalities. METHODS: A health facility-based cross-sectional study was conducted at Felege Hiwot Comprehensive Specialized Hospital (FHCSH), Bahir Dar-Ethiopia. Women aged ≥ 30 years who visited the hospital gynecology unit from 01 March 2019 to 30 October 2021 were included. Following general and pelvic examinations, a senior gynecologist collected cervical punch biopsies for histopathological examinations and cervical swabs for HR-HPV detection using the Abbott Alinity m system (Abbott Molecular, Des Plaines, IL, USA). Extended genotyping was carried out with the INNO-LiPA HPV Genotyping Extra II assay (INNO-LiPA; Fujirebio Europe, Ghent, Belgium) as per the manufacturer protocols at the Institute of Virology, Leipzig University Hospital, Germany. RESULTS: We included 355 women with a mean age of 46.4 ± 11.4 years. The majority of the participants, 277 (79.4%) were sexually active before the age of 18 years and 180 (51.6%) had multiple sexual partners. Forty-eight (13.5%) of the participants were HIV positive. The proportion of HR-HPV was 53.0% (n = 188; 95%CI: 47.8-58.1%). From these samples, 13 different HR-HPV types with a total of 258 sequences were identified. The detection of HR-HPV increased significantly with an increase in the age of the participants. The predominant identified HR-HPV was HPV16, 50.4% followed by HPV31 (9.7%), HPV33 (8.5%), HPV39, and HPV68 each (5.8%) and HPV18 (4.7%). Of the total HR-HPV-positive women, 23.9% (45/188) were infected with multiple HR-HPV types. All HPV16, HPV18, HPV35, and HPV45 genotypes (as a single or in coinfections) were found to be associated with either high-grade lesions or cervical cancer. CONCLUSIONS: HR-HPV infection was reportedly higher among women in the present study area. Based on our findings, we strongly recommend the nonavalent HPV vaccine for immunization and any HPV-based screening method to take into consideration the predominant genotypes circulating in the country. The role of multiple HPV infections in high-grade cervical lesions entails further study in Ethiopia.

18.
Infect Drug Resist ; 15: 1981-1994, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35480057

RESUMO

Background: Viral gastroenteritis belongs to the major public health problems of infant and children worldwide. The largest proportion of morbidity and mortality occurs in Sub-Saharan Africa. Purpose: Aimed to assess the burden and genetic diversity of enteric viruses among children with diarrhea. Patients and Methods: A cross-sectional study was undertaken from December 2015 to April 2016 in Debre Tabor. A total of thirty-eight children, who presented with diarrhea at Debre Tabor health centers, were included. Fecal samples were collected and screened for enteric viruses by RT-PCR. Data were analyzed using SPSS software. Descriptive summary techniques were used to display the findings. Results: Out of thirty-eight children screened, 52.6% were positive for at least one enteric virus. Six (30.0%) of the children had mixed enteric virus infections. Human adenovirus (HAdV) 7 (18.4%) was predominant followed by noroviruses (NoVs) 5 (13.2%), enterovirus (EV) 5 (13.2%), rotavirus A (RVA) 4 (10.5%), human astrovirus (HAstV) 2 (5.3%), and human parechovirus (HPeV) 1 (2.6%). Overall, nineteen different types of enteric virus genotypes were identified. Diverse adenovirus within species A (HAdV-12,-31), B (HAdV-3), C (HAdV-2), and F (HAdV-4) were detected. Norovirus II (GII.4 and GII.6) and norovirus I (GI.2, GI.3, and GI.5) genotypes were found. Sapovirus genotypes within genogroup II (GII.1, GII.5, and GII.6) were identified. Wild-type rotavirus G9 and P[8] genotypes were detected in one of the rotavirus positive samples. Non-polio enteroviruses within species A (coxsackie A virus (CAV) 5, CAV6, and CAV14) and C (enterovirus (EV-C) 99) were also identified. In two of the fecal samples classic HAstV-2 was detected. Conclusion: Diverse enteric viruses were detected in fecal samples from under-five children with diarrhea. The detection of heterogeneous enteric viruses in this small data set highlights the need for extended multicenter studies to describe the burden and genetic diversity of enteric virus.

19.
PLoS One ; 17(11): e0276687, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36378635

RESUMO

BACKGROUND: Despite the availability of effective vaccines and treatments for hepatitis B virus (HBV), it continues to be a major public health problem in sub-Saharan Africa including Ethiopia. Routine screening for HBV in pregnant women is widely recommended, but there is lack of screening for HBV during pregnancy in Ethiopia. Therefore, this study aimed to assess viral load, and genetic diversity among pregnant women in the Amhara National Regional State, Ethiopia. MATERIALS AND METHODS: Hepatitis B surface antigen (HBsAg) testing was performed on 1846 pregnant women, 85 of who tested positive were included in this study. HBV DNA was isolated from 85 positive sera, and the partial surface/polymerase gene was amplified and sequenced. HBV genotypes, sub-genotypes, serotypes and mutations in surface genes and polymerase were studied. RESULTS: Out of 85 pregnant women`s HBsAg positive sera, 59(69.4%) had detectable viral DNA. The median viral load was 3.4 log IU/ml ranging from 2.6 to7.6 and 46 samples were successfully sequenced and genotyped. Genotypes A and D were identified in 39 (84.8%) and 7 (15.2%); respectively. All genotype A isolates were further classified into sub-genotype A1 and serotype adw2 (84.8%) whereas genotype D isolates were further classified into three sub genotypes; 2 (4.3%) D2, 1(2.2%) D4, and 4 (8.7%) D10 with serotypes ayw2 (10.9%), and ayw3 (4.3%). There were 19 (41.3%) surface gene mutations in the major hydrophilic region (MHR). Six (13.1%) of them were discovered in MHR`s `a'-determinant region. Six polymerase gene mutations (13%) were identified. CONCLUSION: Genotype A was the predominant genotype in the Amhara National Regional State. The surface and polymerase gene mutations identified in this study may lead to immune therapy failure, diagnostics escape and drug resistance. Thus, the data generated in this study will contribute to the planning of HBV diagnosis, vaccination and treatment, and most importantly to the prevention of vertical transmission of HBV in Ethiopia. Therefore, further molecular studies on HBV are warranted and continuous surveillance is important for patient management and for the prevention and control of HBV infection in the country.


Assuntos
Vírus da Hepatite B , Hepatite B , Humanos , Feminino , Gravidez , Antígenos de Superfície da Hepatite B/genética , Etiópia/epidemiologia , Gestantes , Hepatite B/epidemiologia , DNA Viral/genética , Genótipo , Mutação
20.
Viruses ; 13(10)2021 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-34696390

RESUMO

Globally and in all age groups, noroviruses are a main cause of gastroenteritis. To assess their local epidemiology and genetic diversity, stool samples of 7509 inpatients with gastrointestinal complaints from all age groups were analyzed. After detection of norovirus genogroup I and II RNA by real-time RT-PCR, viral capsids were genotyped by partial nucleic acid sequencing. In the case of GII.2 strains, polymerase genotypes were also assessed. Between October 2013 and September 2017, presence of norovirus RNA was shown in 611 samples (8.1%), of which 610 (99.8%) were typed successfully. Norovirus positivity rate was higher in patients aged below five years (14.8%) than in older patients (5.7%). Among the 611 norovirus positive samples, GII.4 (56.6%) strains prevailed, followed by GII.6 (11.3%), GII.3 (11.0%) and GII.2 (9.5%). The most common genogroup I (GGI) genotype was GI.3 (3.6%). In addition, rare genotypes such as GII.13, GII.14 and GII.26 were detected. Interestingly, GII.3 infections were most common in children under the age of five years. Assessment of polymerase genotypes in GII.2 viruses showed a shift from P2 to P16, with higher diversity in P2 sequences. The varying distribution of norovirus genotypes depending on season, age and setting of infection highlights the importance of frequent genotyping as a basis for vaccine development and needful adjustments.


Assuntos
Infecções por Caliciviridae/epidemiologia , Variação Genética , Genótipo , Norovirus/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Fezes/virologia , Feminino , Gastroenterite/epidemiologia , Gastroenterite/virologia , Alemanha/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Norovirus/classificação , Norovirus/patogenicidade , Filogenia , Prevalência , RNA Viral/genética , Adulto Jovem
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