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1.
Int J Med Microbiol ; 314: 151600, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38246091

RESUMEN

Human norovirus is a major cause of viral gastroenteritis in all age groups. The virus is constantly and rapidly changing, allowing mutations and recombination events to create great diversity of circulating viruses. With the start of the COVID-19 pandemic in 2020, a wide range of public health measures were introduced worldwide to control human-to-human transmission of SARS-CoV-2. In Germany, control measures such as distance rules, contact restrictions, personal protection equipment as well as intensive hand hygiene were introduced. To better understand the effect of the measures to control the COVID-19 pandemic on incidence and the molecular epidemiological dynamics of norovirus outbreaks in Germany, we analyzed national notification data between July 2017 and December 2022 and characterized norovirus sequences circulating between January 2018 and December 2022. Compared to a reference period before the pandemic, the incidence of notified norovirus gastroenteritis decreased by 89.7% to 9.6 per 100,000 during the 2020/2021 norovirus season, corresponding to an incidence rate ratio (IRR) of 0.10. Samples from 539 outbreaks were genotyped in two regions of the viral genome from pre-pandemic (January 2018 to February 2020) and samples from 208 outbreaks during pandemic time period (March 2020 to December 2022). As expected, norovirus outbreaks were mainly found in child care facilities and nursing homes. In total, 36 genotypes were detected in the study period. A high proportion of recombinant strains (86%) was found in patients, the proportion of detected recombinant viruses did not vary between the pre-pandemic and pandemic phase. The proportion of the predominant recombinant strain GII.4 Sydney[P16] was unchanged before pandemic and during pandemic at 37.5%. The diversity of most common genotypes in nursing homes and child care facilities showed a different proportion of genotypes causing outbreaks. In nursing homes as well as in child care facilities GII.4 Sydney[P16] was predominant during the whole study period. Compared to the nursing homes, a greater variety of genotypes at the expense of GII.4 Sydney[P16] was detected in child care facilities. Furthermore, the overall proportion of recombinant strain GII.3[P12] increased during the pandemic, due to outbreaks in child care facilities. The COVID-19 pandemic had a high impact on the occurrence of sporadic cases and norovirus outbreaks in Germany, leading to a near suppression of the typical norovirus winter season following the start of the pandemic. The number of norovirus-associated outbreak samples sent to the Consultant Laboratory dropped by 63% during the pandemic. We could not identify a clear influence on circulating norovirus genotypes. The dominance of GII.4 Sydney recombinant strains was independent from the pandemic. Further studies are needed to follow up on the diversity of less predominant genotypes to see if the pandemic could have acted as a bottleneck to the spread of previously minoritized genotypes like GII.3[P12].


Asunto(s)
COVID-19 , Infecciones por Caliciviridae , Gastroenteritis , Norovirus , Humanos , Gastroenteritis/epidemiología , Norovirus/genética , Pandemias , COVID-19/epidemiología , Infecciones por Caliciviridae/epidemiología , SARS-CoV-2/genética , Genotipo , Brotes de Enfermedades , Filogenia
2.
Metabolomics ; 20(2): 23, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38347335

RESUMEN

INTRODUCTION: Animal welfare in aquaculture is becoming increasingly important, and detailed knowledge of the species concerned is essential for further optimization on farms. Every organism is controlled by an internal clock, the circadian rhythm, which is crucial for metabolic processes and is partially influenced by abiotic factors, making it important for aquaculture practices. OBJECTIVE: In order to determine the circadian rhythm of adult turbot (Scophthalmus maximus), blood samples were collected over a 24-h period and plasma metabolite profiles were analyzed by 1H-NMR spectroscopy. METHODS: The fish were habituated to feeding times at 9 am and 3 pm and with the NMR spectroscopy 46 metabolites could be identified, eight of which appeared to shift throughout the day. RESULTS: We noted exceptionally high values around 3 pm for the amino acids isoleucine, leucine, valine, phenylalanine, lysine, and the stress indicator lactate. These metabolic peaks were interpreted as either habituation to the usual feeding time or as natural peak levels in turbot in a 24-h circle because other indicators for stress (glucose, cortisol and lysozymes) showed a stable baseline, indicating that the animals had no or very little stress during the experimental period. CONCLUSION: This study provides initial insights into the diurnal variation of metabolites in adult turbot; however, further studies are needed to confirm present findings of possible fluctuations in amino acids and sugars. Implementing optimized feeding times (with high levels of sugars and low levels of stress metabolites) could lead to less stress, fewer disease outbreaks and overall improved fish welfare in aquaculture facilities.


Asunto(s)
Peces Planos , Animales , Peces Planos/metabolismo , Metabolómica , Ritmo Circadiano , Acuicultura/métodos , Aminoácidos/metabolismo , Azúcares/metabolismo
3.
Phytopathology ; 114(2): 378-392, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37606348

RESUMEN

Disease severity in plant pathology is often measured by the amount of a plant or plant part that exhibits disease symptoms. This is typically assessed using a numerical scale, which allows a standardized, convenient, and quick method of rating. These scales, known as quantitative ordinal scales (QOS), divide the percentage scale into a predetermined number of intervals. There are various ways to analyze these ordinal data, with traditional methods involving the use of midpoint conversion to represent the interval. However, this may not be precise enough, as it is only an estimate of the true value. In this case, the data may be considered interval-censored, meaning that we have some knowledge of the value but not an exact measurement. This type of uncertainty is known as censoring, and techniques that address censoring, such as survival analysis (SA), use all available information and account for this uncertainty. To investigate the pros and cons of using SA with QOS measurements, we conducted a simulation based on three pathosystems. The results showed that SA almost always outperformed midpoint conversion with data analyzed using a t test, particularly when data were not normally distributed. Midpoint conversion is currently a standard procedure. In certain cases, the midpoint approach required a 400% increase in sample size to achieve the same power as the SA method. However, as the mean severity increases, fewer additional samples are needed (approximately an additional 100%), regardless of the assessment method used. Based on these findings, we conclude that SA is a valuable method for enhancing the power of hypothesis testing when analyzing QOS severity data. Future research should investigate the wider use of survival analysis techniques in plant pathology and their potential applications in the discipline.


Asunto(s)
Enfermedades de las Plantas , Patología de Plantas , Simulación por Computador , Gravedad del Paciente , Análisis de Supervivencia
4.
Phys Rev Lett ; 130(5): 051803, 2023 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-36800477

RESUMEN

The COHERENT Collaboration searched for scalar dark matter particles produced at the Spallation Neutron Source with masses between 1 and 220 MeV/c^{2} using a CsI[Na] scintillation detector sensitive to nuclear recoils above 9 keV_{nr}. No evidence for dark matter is found and we thus place limits on allowed parameter space. With this low-threshold detector, we are sensitive to coherent elastic scattering between dark matter and nuclei. The cross section for this process is orders of magnitude higher than for other processes historically used for accelerator-based direct-detection searches so that our small, 14.6 kg detector significantly improves on past constraints. At peak sensitivity, we reject the flux consistent with the cosmologically observed dark-matter concentration for all coupling constants α_{D}<0.64, assuming a scalar dark-matter particle. We also calculate the sensitivity of future COHERENT detectors to dark-matter signals which will ambitiously test multiple dark-matter spin scenarios.

5.
Phys Rev Lett ; 131(22): 221801, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38101357

RESUMEN

Using an 185-kg NaI[Tl] array, COHERENT has measured the inclusive electron-neutrino charged-current cross section on ^{127}I with pion decay-at-rest neutrinos produced by the Spallation Neutron Source at Oak Ridge National Laboratory. Iodine is one the heaviest targets for which low-energy (≤50 MeV) inelastic neutrino-nucleus processes have been measured, and this is the first measurement of its inclusive cross section. After a five-year detector exposure, COHERENT reports a flux-averaged cross section for electron neutrinos of 9.2_{-1.8}^{+2.1}×10^{-40} cm^{2}. This corresponds to a value that is ∼41% lower than predicted using the MARLEY event generator with a measured Gamow-Teller strength distribution. In addition, the observed visible spectrum from charged-current scattering on ^{127}I has been measured between 10 and 55 MeV, and the exclusive zero-neutron and one-or-more-neutron emission cross sections are measured to be 5.2_{-3.1}^{+3.4}×10^{-40} and 2.2_{-0.5}^{+0.4}×10^{-40} cm^{2}, respectively.

6.
Virol J ; 20(1): 40, 2023 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-36864463

RESUMEN

BACKGROUND: Rotavirus A (RVA) infections remain a major cause of severe acute diarrhea affecting children worldwide. To date, rapid diagnostic tests (RDT) are widely used to detect RVA. However, paediatricians question whether the RDT can still detect the virus accurately. Therefore, this study aimed to evaluate the performance of the rapid rotavirus test in comparison to the one-step RT-qPCR method. METHODS: A cross-sectional study was conducted in Lambaréné, Gabon, from April 2018 to November 2019. Stool samples were collected from children under 5 years of age with diarrhoea or a history of diarrhoea within the last 24 h, and from asymptomatic children from the same communities. All stool samples were processed and analysed using the SD BIOLINE Rota/Adeno Ag RDT against a quantitative reverse transcription PCR (RT-qPCR), which is considered the gold standard. RESULTS: For a total of 218 collected stool samples, the overall sensitivity of the RDT was 46.46% (confidence interval (CI) 36.38-56.77), with a specificity of 96.64% (CI 91.62-99.08) compared to one-step RT-qPCR. After confirming the presence or absence of RVA gastroenteritis, the RDT showed suitable results in detecting rotavirus A-associated disease, with a 91% concordance with the RT-qPCR. Furthermore, the performance of this test varied when correlated with seasonality, symptoms, and rotavirus genotype. CONCLUSION: This RDT showed high sensitivity and was suitable for the detection of RVA in patients with RVA gastroenteritis, although some asymptomatic RVA shedding was missed by RT-qPCR. It could be a useful diagnostic tool, especially in low-income countries.


Asunto(s)
Infecciones por Enterovirus , Gastroenteritis , Infecciones por Rotavirus , Rotavirus , Niño , Humanos , Lactante , Preescolar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estudios Transversales , Diarrea/diagnóstico , Rotavirus/genética , Infecciones por Rotavirus/diagnóstico
7.
Phys Rev Lett ; 129(8): 081801, 2022 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-36053683

RESUMEN

We measured the cross section of coherent elastic neutrino-nucleus scattering (CEvNS) using a CsI[Na] scintillating crystal in a high flux of neutrinos produced at the Spallation Neutron Source at Oak Ridge National Laboratory. New data collected before detector decommissioning have more than doubled the dataset since the first observation of CEvNS, achieved with this detector. Systematic uncertainties have also been reduced with an updated quenching model, allowing for improved precision. With these analysis improvements, the COHERENT Collaboration determined the cross section to be (165_{-25}^{+30})×10^{-40} cm^{2}, consistent with the standard model, giving the most precise measurement of CEvNS yet. The timing structure of the neutrino beam has been exploited to compare the CEvNS cross section from scattering of different neutrino flavors. This result places leading constraints on neutrino nonstandard interactions while testing lepton flavor universality and measures the weak mixing angle as sin^{2}θ_{W}=0.220_{-0.026}^{+0.028} at Q^{2}≈(50 MeV)^{2}.

8.
Artículo en Alemán | MEDLINE | ID: mdl-35029725

RESUMEN

Viral hepatitis A to E describes various infectious inflammations of the liver parenchyma that are caused by the hepatitis viruses A to E (HAV, HBV, HCV, HDV, and HEV). Although the clinical pictures are similar, the pathogens belong to different virus families and differ in terms of pathogenesis, transmission routes, clinical course, prevention, and therapy options. In Germany, there is mandatory reporting according to the Infection Protection Act (IfSG) for direct or indirect laboratory evidence and for suspicion, illness, and death of viral hepatitis. The data are transmitted to the Robert Koch Institute.In this article, on the basis of published studies and notification data, we describe the epidemiology of hepatitis A to E as well as current challenges and prevention approaches. In particular, the latter contains the improvement of existing vaccination recommendations (hepatitis A and B); improvement of access to prevention, testing, and care including therapy with antiviral drugs (hepatitis B, C, and D) and the detection and prevention of foodborne infections and outbreaks; and improvements in the field of food safety (hepatitis A and E).


Asunto(s)
Hepatitis A , Hepatitis B , Hepatitis Viral Humana , Alemania/epidemiología , Hepatitis A/diagnóstico , Hepatitis A/epidemiología , Hepatitis A/prevención & control , Virus de Hepatitis , Hepatitis Viral Humana/diagnóstico , Hepatitis Viral Humana/epidemiología , Hepatitis Viral Humana/prevención & control , Humanos
9.
J Viral Hepat ; 28(1): 196-204, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32869414

RESUMEN

The hepatitis E virus (HEV) is one of the most common causes of hepatitis worldwide. HEV is also widespread in many developed countries, where the number of infections is steadily increasing. In those countries, the virus is transmitted mainly through consumption of undercooked or raw food or through contact with animals. Especially, pigs serve as a main reservoir of HEV. Here, we investigated the prevalence of HEV RNA in pork livers and pork meat products to assess the actual risk of HEV infection through food consumption in Germany. A total of 131 pork products were collected from grocery stores and butcher shops between October 2019 and February 2020 and screened for HEV RNA using nested PCR and subsequent sequencing. Overall, 10% of the samples were positive for HEV, including pork livers (5%), spreadable liver sausages (13%) and liver pâté samples (15%). Sequence analyses indicated that the large majority of HEV strains belonged to subtype HEV-3c, representing the most frequent subtype in Germany. One sample belonged to subtype HEV-3f. Further sequence analysis revealed large sequence variation between the samples; however, most of the mutations identified were synonymous. Although infectivity of the virus was not tested, the results suggest a considerable risk of HEV infection through food consumption. Therefore, preventive measures should be taken according to a One Health approach.


Asunto(s)
Virus de la Hepatitis E , Hepatitis E , Productos de la Carne , Carne de Cerdo , Carne Roja , Animales , Alemania/epidemiología , Hepatitis E/epidemiología , Virus de la Hepatitis E/genética , Hígado , ARN Viral/genética , Porcinos
10.
Virol J ; 18(1): 20, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-33446224

RESUMEN

BACKGROUND: Coinfections of HIV-positive individuals with Hepatitis B and D virus (HBV and HDV) are common and can be associated with rapid liver damage. Several antiretroviral drugs for HIV exhibit anti-HBV effect; however, the selection of HBV drug resistance mutations (DRMs) in individuals under HIV antiretroviral therapy (ART) has been reported but rarely in Nigeria. In this study the HBV/HDV prevalence and HBV DRMs in HIV-positive individuals in Southwestern Nigeria were assessed. METHODS: Plasma samples collected from 310 HIV-positive individuals including 295 ART-experienced and 15 ART-naïve persons attending the HIV clinic in three south-western states of Nigeria between June 2017 and August 2017 were analysed by ELISA for HBsAg and anti-HDV. The presence of HDV RNA and HBV DNA was analysed by (RT)-PCR followed by sequencing and phylogenetic analyses for genotyping. The HBV reverse transcription (RT) region was amplified and sequenced for the analysis of drug resistance mutations. RESULTS: Overall, 16.1% (n = 50/310) of the HIV-positive individuals were positive for HBsAg, most of which were ART-experienced (94.0%; n = 47/50). From the 50 HBsAg-positive samples, 72.0% (n = 36/50) were positive for HBV DNA and 16.0% (n = 8/50) had detectable HDV RNA while 5.6% (n = 2/36) of the HBV-DNA positive samples had anti-HDV total antibodies. Sequences were available for 31/36 of the HBV DNA-positive and 3/8 HDV RNA-positive samples. HBV DNA-positive samples were characterised as HBV genotype E infections exclusively, while HDV genotype 1 was detected in the HDV RNA-positive samples. HBV DRMs V173L, L180M, S202I and M204V/I, which are associated with lamivudine resistance, were detected in 32.2% (n = 10/31) of the HBV DNA-positive samples. Most of these mutations (90.0%; n = 9/10) were present in the ART-experienced cohort. CONCLUSIONS: This study indicates that HBV/HDV coinfections are common in HIV-positive individuals under ART in Nigeria. Furthermore, a high proportion of HBV DRMs which potentially compromise future treatment options were detected, underscoring the need for HBV screening prior to starting ART. Further studies should be performed to monitor a possible increase in the spread of HDV among populations at risk of HIV and HBV infections.


Asunto(s)
Coinfección/epidemiología , Coinfección/virología , Infecciones por VIH/epidemiología , Hepatitis B/genética , Hepatitis D/epidemiología , Virus de la Hepatitis Delta/genética , Adolescente , Adulto , Anciano , Antirretrovirales/uso terapéutico , Niño , Preescolar , Femenino , Genotipo , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Anticuerpos Antihepatitis/sangre , Hepatitis B/epidemiología , Virus de la Hepatitis Delta/clasificación , Humanos , Masculino , Persona de Mediana Edad , Mutación , Nigeria/epidemiología , Filogenia , Prevalencia , Adulto Joven
11.
Phytopathology ; 111(2): 244-252, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33151825

RESUMEN

Pecan scab, caused by Venturia effusa, is the most economically damaging disease of pecan in the southeastern United States, and annual epidemics are most effectively managed through multiple fungicide applications. The fungicide applications can be the single greatest operating cost for commercial growers and the return on that investment is impacted by fungicide resistance. V. effusa produces multiple generations of conidia per season, exhibits substantial genetic diversity, overwinters as stromata in the tree, and is under immense selection from the applied fungicides, all of which lead to a high risk for developing fungicide resistance. Since the mid-1970s, resistance or reduced sensitivity has been observed in isolates of V. effusa to the methyl benzimidazole carbamates, demethylation inhibitors, quinone outside inhibitors, organotin compounds, and the guanidines. Over the last 10 years, several studies have been conducted that have improved both scab management and fungicide resistance management in V. effusa. The aim of this review is to summarize recent developments in our understanding of fungicide resistance in V. effusa in the context of scab management in southeastern pecan orchards. The history, modes of action, general use of the labeled fungicides, and mechanisms and stability of fungicide resistance in V. effusa are discussed; conclusions and future research priorities are also presented.


Asunto(s)
Ascomicetos , Carya , Fungicidas Industriales , Hongos del Género Venturia , Fungicidas Industriales/farmacología , Enfermedades de las Plantas , Sudeste de Estados Unidos
12.
Plant Dis ; 105(2): 377-383, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32729799

RESUMEN

An 18-ha commercial pecan orchard was sampled over 3 years to study the spatial and temporal variation in fungicide sensitivity of Venturia effusa, cause of pecan scab. The orchard was divided into a two-dimensional, 8 × 8 grid of 64 quadrats, each containing nine trees (unless there were missing trees), and samples were collected once per year from each quadrat to be tested for sensitivity to fentin hydroxide, propiconazole, and thiophanate-methyl. Averaged across the orchard, insensitivity to all three fungicides was significantly lower in 2016 compared with 2015, but significantly greater for fentin hydroxide and thiophanate-methyl in 2017. Although significant spatial autocorrelation was observed for sensitivity to propiconazole in 2017 and for thiophanate-methyl in 2015 and 2017, indicating clustering, all other fungicide-by-year combinations were not significant. Omnidirectional spatial dependence was observed for sensitivity to propiconazole and thiophanate-methyl in 2017. In both instances, the semivariance increased linearly with lag distance; however, the range of spatial dependence was >276.5 m and could not be estimated accurately. Additionally, a separate sampling was conducted in all 3 years to identify an appropriate sampling size and pattern for fungicide sensitivity screening. A leaflet sample size of 165 in 11 groups of 15 allowed for accurate sensitivity testing for the three fungicides in all 3 years; however, a sample size of 45 leaflets in three groups of 15 was sufficient for quantifying sensitivity for propiconazole and thiophanate-methyl, in most cases. These results indicate that considerable biological variation in fungicide sensitivity exists in orchard-scale populations of V. effusa and that the spatial characteristics of those populations may differ in two-dimensional space depending on the growing season.


Asunto(s)
Ascomicetos , Carya , Fungicidas Industriales , Hongos del Género Venturia , Fungicidas Industriales/farmacología , Tiofanato
13.
Phytopathology ; 110(4): 734-743, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31859585

RESUMEN

Studies in plant pathology, agronomy, and plant breeding requiring disease severity assessment often use quantitative ordinal scales (i.e., a special type of ordinal scale that uses defined numeric ranges); a frequently used example of such a scale is the Horsfall-Barratt scale. Parametric proportional odds models (POMs) may be used to analyze the ratings obtained from quantitative ordinal scales directly, without converting ratings to percent area affected using range midpoints of such scales (currently a standard procedure). Our aim was to evaluate the performance of the POM for comparing treatments using ordinal estimates of disease severity relative to two alternatives, the midpoint conversions (MCs) and nearest percent estimates (NPEs). A simulation method was implemented and the parameters of the simulation estimated using actual disease severity data from the field. The criterion for comparison of the three approaches was the power of the hypothesis test (the probability to reject the null hypothesis when it is false). Most often, NPEs had superior performance. The performance of the POM was never inferior to using the MC at severity <40%. Especially at low disease severity (≤10%), the POM was superior to using the MC method. Thus, for early onset of disease or for comparing treatments with severities <40%, the POM is preferable for analyzing disease severity data based on quantitative ordinal scales when comparing treatments and at severities >40% is equivalent to other methods.


Asunto(s)
Enfermedades de las Plantas , Patología de Plantas , Recolección de Datos , Probabilidad , Proyectos de Investigación
14.
Virol J ; 16(1): 28, 2019 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-30832687

RESUMEN

BACKGROUND: HCV exhibits a high genetic diversity and is classified into 7 genotypes which are further divided into 86 confirmed subtypes. However, there are multiple isolates with unassigned subtypes. We aimed to amplify and characterize the full-length genome sequence of an HCV genotype 1 (HCV-1) divergent isolate (DE/17-0414) in Germany. METHODS: The HCV infection was detected in an HIV-1-positive German female within an HCV/HIV-coinfection study using a commercially available antigen-antibody HCV ELISA kit and confirmed by an in-house quantitative real-time RT-PCR assay. Preliminary genotyping was done by sequencing and phylogenetic analysis on partial NS5B region. The full-length genome sequence was determined by consensus RT-PCR assays. Resistance-associated substitutions (RASs) were analyzed using the web-based tool Geno2pheno[HCV]. RESULTS: Partial NS5B region of the isolate DE/17-0414 showed more than 95% identity to 73-08460349-1 l and HCV_Fr_003 from France and QC316 from Canada. Full-length genome analysis of the DE/17-0414 strain showed 91.8% identity to QC316 but less than 79.6% to other HCV-1 strains. Phylogenetic analyses demonstrated that DE/17-0414, 73-08460349-1 l, HCV_Fr_003, and QC316 formed a separate subcluster within HCV-1. DE/17-0414 had a distinct 3 amino acids insertion at the N-terminal of hypervariable region 1 (HVR1) within viral envelope glycoprotein 2 (E2) and several potential antiviral RASs among the NS3 and NS5A genes. CONCLUSIONS: We identified and analyzed an HCV-1 divergent isolate derived from an HIV-1 coinfected individual in Germany, which will be assigned to a new HCV-subtype 1o. Our understanding of the origin and transmission dynamics of this new subtype 1o requires further assessments from patients worldwide.


Asunto(s)
Variación Genética , Genotipo , Infecciones por VIH/virología , Hepacivirus/clasificación , Femenino , Genoma Viral , Alemania , VIH-1 , Hepacivirus/aislamiento & purificación , Humanos , Persona de Mediana Edad , Filogenia , Análisis de Secuencia de ADN , Proteínas del Envoltorio Viral/genética , Proteínas no Estructurales Virales/genética
15.
J Clin Microbiol ; 56(5)2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29514938

RESUMEN

Autochthonous hepatitis E virus genotype 3 (HEV-3) infections in industrialized countries are more frequent than previously assumed. HEV-3 is zoonotic and the causal pathogen of chronic hepatitis E. According to the latest classification of the family Hepeviridae, 10 designated HEV-3 subtypes (HEV-3a to HEV-3j) and 7 unassigned HEV-3 subtypes are proposed. In order to identify and characterize the HEV-3 variants in circulation, we developed a molecular approach combining a sensitive HEV-specific real-time reverse transcription-PCR (RT-PCR) targeting the overlapping region of HEV ORF2 and ORF3 (the ORF2/3 region) and two newly designed consensus nested RT-PCRs targeting the HEV ORF1 and ORF2 genes, respectively. Since complete genome sequences are required for new HEV-3 subtype assignment, we implemented a straightforward approach for full-length HEV-3 genome amplification. Twenty-nine human serum samples and six human feces samples from chronic hepatitis E patients were selected for evaluation of the system. Viral loads ranged from 1 × 104 to 1.9 × 1010 copies/ml of serum and from 1.8 × 104 to 1 × 1012 copies/g of feces. Sequence and phylogenetic analyses of partial ORF1 and ORF2 sequences showed that HEV strains had considerable genetic diversity and clustered into the HEV-3c (29/35), HEV-3e (2/35), HEV-3f (2/35), and unassigned HEV-3 (2/35) subtypes. Moreover, from these strains, three full-length HEV-3 genome sequences were generated and characterized. DE/15-0030 represents a typical HEV-3c strain (95.7% nucleotide identity to wbGER27), while DE/15-0031 and SW/16-0282 have <89.2% homology to known HEV-3 strains and are phylogenetically divergent, indicating novel HEV-3 subtypes. In summary, our approach will significantly facilitate the detection, quantification, and determination of HEV-3 strains and will thus help to improve molecular diagnostics and our knowledge of HEV diversity and evolution.


Asunto(s)
Variación Genética , Genotipo , Virus de la Hepatitis E/clasificación , Virus de la Hepatitis E/genética , Hepatitis E/virología , Análisis por Conglomerados , Heces/virología , Virus de la Hepatitis E/aislamiento & purificación , Humanos , Filogenia , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Homología de Secuencia , Suero/virología , Carga Viral
16.
J Med Virol ; 90(2): 239-249, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28906005

RESUMEN

Nigeria having approximately 50 000 Rotavirus A (RVA) deaths annually is yet to introduce RVA vaccine into routine national immunization; therefore surveillance of RVA strains circulating before vaccine introduction is essential in evaluating impact of the intervention. Stool samples and sociodemographic data of diarrhoeic children, <5 years were collected between August 2012 and December 2013. While a high prevalence of RVA infection (47.6%; 49/103) was observed by quantitative reverse transcription real time PCR, only 25% (26/103) had high RVA genome concentrations and were antigen positive. G and P types were obtained for 31 and 37 samples respectively. G12P[8] strains were predominant (30.6%; 16/31); Other genotypes found included G9, G3, G2 and P[4], P[6], P[8]. A G12 + G2/P[8] + P[6] mixed infection was detected. The P[8] genotype showed divergence with strains distributed in lineage III and IV. Compared to the vaccines, changes in antigenic sites of VP8* and VP7 were found. The finding of the G2P[6] genotype combination and emergence of G12 strains support observations in most of the recent RVA studies from Africa. P[6] is common in many African countries, in contrast to countries in Europe and the Americas. In conclusion, this study shows the circulation of other RVA genotypes compared to the common RVA genotypes in Nigeria. PCR results should be interpreted with caution to avoid significant bias from samples with low RVA genome concentrations. These findings provide important information on the detection and molecular epidemiology of RVA prior to vaccination and contribute as a baseline for future evaluations after possible vaccine introduction.


Asunto(s)
Antígenos Virales/genética , Proteínas de la Cápside/genética , Genotipo , Infecciones por Rotavirus/epidemiología , Infecciones por Rotavirus/virología , Rotavirus/clasificación , Rotavirus/genética , Preescolar , Heces/virología , Femenino , Variación Genética , Humanos , Lactante , Recién Nacido , Masculino , Epidemiología Molecular , Nigeria/epidemiología , Prevalencia , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rotavirus/aislamiento & purificación
17.
Virol J ; 15(1): 163, 2018 10 23.
Artículo en Inglés | MEDLINE | ID: mdl-30352598

RESUMEN

BACKGROUND: In 2017 the Nigerian Ministry of Health notified the World Health Organization (WHO) of an outbreak of hepatitis E located in the north-east region of the country with 146 cases with 2 deaths. The analysis of the hepatitis E virus (HEV) genotypes responsible for the outbreak revealed the predominance of HEV genotypes 1 (HEV-1) and 2 (HEV-2). Molecular data of HEV-2 genomes are limited; therefore we characterized a HEV-2 strain of the outbreak in more detail. FINDING: The full-length genome sequence of an HEV-2 strain (NG/17-0500) from the outbreak was amplified using newly designed consensus primers. Comparison with other HEV complete genome sequences, including the only HEV-2 strain (Mex-14) with available complete genome sequences and the availability of data of partial HEV-2 sequences from Sub-Saharan Africa, suggests that NG/17-0500 belongs to HEV subtype 2b (HEV-2b). CONCLUSIONS: We identified a novel HEV-2b strain from Sub-Saharan Africa, which is the second complete HEV-2 sequence to date, whose natural history and epidemiology merit further investigation.


Asunto(s)
Brotes de Enfermedades , Genoma Viral/genética , Virus de la Hepatitis E/clasificación , Virus de la Hepatitis E/aislamiento & purificación , Hepatitis E/epidemiología , Hepatitis E/virología , ARN Viral/genética , ADN Complementario/genética , Genotipo , Hepatitis E/sangre , Virus de la Hepatitis E/genética , Humanos , Nigeria/epidemiología , Filogenia , ARN Viral/sangre , Análisis de Secuencia de ADN , Análisis de Secuencia de Proteína
18.
Euro Surveill ; 22(4)2017 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-28181902

RESUMEN

Since early November 2016, the number of laboratory-confirmed norovirus infections reported in Germany has been increasing steeply. Here, we report the detection and genetic characterisation of an emerging norovirus recombinant, GII.P16-GII.2. This strain was frequently identified as the cause of sporadic cases as well as outbreaks in nine federal states of Germany. Our findings suggest that the emergence of GII.P16-GII.2 contributed to rising case numbers of norovirus gastroenteritis in Germany.


Asunto(s)
Infecciones por Caliciviridae/epidemiología , Brotes de Enfermedades , Gastroenteritis/virología , Genotipo , Norovirus/clasificación , Norovirus/genética , Infecciones por Caliciviridae/virología , Niño , Preescolar , Diarrea/epidemiología , Diarrea/virología , Notificación de Enfermedades/estadística & datos numéricos , Gastroenteritis/epidemiología , Variación Genética , Alemania/epidemiología , Humanos , Lactante , Norovirus/aislamiento & purificación , Filogenia , ARN Viral/genética , Estaciones del Año , Análisis de Secuencia de ADN
19.
Gut ; 65(10): 1733-43, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27222534

RESUMEN

OBJECTIVE: Hepatitis E virus (HEV) infection can take chronic courses in immunocompromised patients potentially leading to liver cirrhosis and liver failure. Ribavirin (RBV) is currently the only treatment option for many patients, but treatment failure can occur which has been associated with the appearance of a distinct HEV polymerase mutant (G1634R). Here, we performed a detailed analysis of HEV viral intrahost evolution during chronic hepatitis E infections. DESIGN: Illumina deep sequencing was performed for the detection of intrahost variation in the HEV genome of chronically infected patients. Novel polymerase mutants were investigated in vitro using state-of-the-art HEV cell culture models. RESULTS: Together, these data revealed that (1) viral diversity differed markedly between patients but did not show major intraindividual short-term variations in untreated patients with chronic hepatitis E, (2) RBV therapy was associated with an increase in viral heterogeneity which was reversible when treatment was stopped, (3) the G1634R mutant was detectable as a minor population prior to therapy in patients who subsequently failed to achieve a sustained virological response to RBV therapy and (4) in addition to G1634R further dominant variants in the polymerase region emerged, impacting HEV replication efficiency in vitro. CONCLUSIONS: In summary, this first investigation of intrahost HEV population evolution indicates that RBV causes HEV mutagenesis in treated patients and that an emergence of distinct mutants within the viral population occurs during RBV therapy. We also suggest that next-generation sequencing could be useful to guide personalised antiviral strategies.


Asunto(s)
Genoma Viral/efectos de los fármacos , Virus de la Hepatitis E , Hepatitis E , Mutagénesis , Ribavirina , Adolescente , Adulto , Anciano , Antivirales/administración & dosificación , Antivirales/efectos adversos , Enfermedad Crónica , Monitoreo de Drogas , Femenino , Heterogeneidad Genética/efectos de los fármacos , Hepatitis E/tratamiento farmacológico , Hepatitis E/fisiopatología , Hepatitis E/virología , Virus de la Hepatitis E/efectos de los fármacos , Virus de la Hepatitis E/genética , Humanos , Masculino , Persona de Mediana Edad , Ribavirina/administración & dosificación , Ribavirina/efectos adversos
20.
J Gen Virol ; 97(8): 1865-1876, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27147296

RESUMEN

An effective immune response against hepatitis C virus (HCV) requires the early development of multi-specific class 1 CD8+ and class II CD4+ T-cells together with broad neutralizing antibody responses. We have produced mammalian-cell-derived HCV virus-like particles (VLPs) incorporating core, E1 and E2 of HCV genotype 1a to produce such immune responses. Here we describe the biochemical and morphological characterization of the HCV VLPs and study HCV core-specific T-cell responses to the particles. The E1 and E2 glycoproteins in HCV VLPs formed non-covalent heterodimers and together with core protein assembled into VLPs with a buoyant density of 1.22 to 1.28 g cm-3. The HCV VLPs could be immunoprecipited with anti-ApoE and anti-ApoC. On electron microscopy, the VLPs had a heterogeneous morphology and ranged in size from 40 to 80 nm. The HCV VLPs demonstrated dose-dependent binding to murine-derived dendritic cells and the entry of HCV VLPs into Huh7 cells was blocked by anti-CD81 antibody. Vaccination of BALB/c mice with HCV VLPs purified from iodixanol gradients resulted in the production of neutralizing antibody responses while vaccination of humanized MHC class I transgenic mice resulted in the prodution of HCV core-specific CD8+ T-cell responses. Furthermore, IgG purified from the sera of patients chronically infected with HCV genotypes 1a and 3a blocked the binding and entry of the HCV VLPs into Huh7 cells. These results show that our mammalian-cell-derived HCV VLPs induce humoral and HCV-specific CD8+ T-cell responses and will have important implications for the development of a preventative vaccine for HCV.


Asunto(s)
Hepacivirus/inmunología , Anticuerpos contra la Hepatitis C/sangre , Linfocitos T/inmunología , Vacunas de Partículas Similares a Virus/inmunología , Animales , Anticuerpos Neutralizantes/sangre , Línea Celular , Células Cultivadas , Hepacivirus/genética , Hepatocitos/virología , Humanos , Ratones Endogámicos BALB C , Ratones Transgénicos , Microscopía Electrónica , Vacunas de Partículas Similares a Virus/administración & dosificación , Vacunas de Partículas Similares a Virus/genética , Vacunas de Partículas Similares a Virus/aislamiento & purificación , Proteínas del Núcleo Viral/genética , Proteínas del Núcleo Viral/inmunología , Proteínas del Núcleo Viral/metabolismo , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/inmunología , Proteínas del Envoltorio Viral/metabolismo , Virosomas/genética , Virosomas/inmunología , Virosomas/metabolismo , Virosomas/ultraestructura
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