Rotavirus Research Articles

Developing communication tools on rotavirus vaccination to support family paediatricians in Italy

BackgroundUniversal rotavirus (RV) vaccination for newborns was introduced in Italy in 2018, but national vaccination coverage is still suboptimal. Effective communication between the family paediatrician (FP) and parents/caregivers is essential to promote vaccination acceptance. This project aimed to support FPs in communicating RV vaccination to parents/caregivers through the development and implementation of demonstrative videos and training modules. MethodsA working group composed of two FPs, two communication professionals, a medical expert from GSK and a clinical psychologist, was formed to establish the key scientific information to be communicated to parents/caregivers and develop the demonstrative videos. Four videos depicting four communication styles (I to IV) were developed based on the Social Styles Theory. Thirty FPs were then asked to pilot test the videos and provide feedback. In addition, two training modules with scientific information were developed to learn how to respond to parents’/caregivers’ objections. ResultsA total of 23 FPs provided feedback after using one or more videos at least five times. Twenty FPs (87.0 %) used mostly-one style, and most (60.0 %) used Style IV. Overall, the feedback was positive, as the majority of FPs (82.6 %, n = 19/23) indicated that the proposed videos were ‘useful’ or ‘extremely useful’ for introducing the RV vaccination to parents/caregivers in their actual practice. Based on this feedback, shorter versions of each video were also produced, and two training modules were developed to support FPs in responding to parental objections. Most FPs 75 % (n = 9/12) found Module 1 ‘very useful’, and all found Module 2 ‘very useful’ (100 %, n = 12/12). ConclusionsThe communication tools developed were well appreciated by the FPs and are expected to support FPs in communicating RV vaccination thereby increasing its coverage. Practicing RV communication may also prove beneficial for FPs to communicate other critical topics to parents/caregivers.

Impact after the Change from Voluntary to Universal Oral Rotavirus Vaccination on Consecutive Emergency Department Visits for Acute Gastroenteritis among Children in Kobe City, Japan (2016-2022).

Rotavirus (RV) is the leading cause of acute gastroenteritis (AGE), particularly in infants. In 2006, the high efficacy of oral RV vaccines (RVVs, RotarixTM and RotaTeqTM) was demonstrated. Voluntary RVV started in Japan in 2011, and in October 2020 were launched as universal oral RVVs in Japan. However, the impact of changes from voluntary to universal RVVs has not been studied in a primary emergency medical center in Japan. We investigated changes in the number of pediatric patients with AGE after introducing universal RVVs in our center. A clinical database of consecutive patients aged <16 who presented to Kobe Children's Primary Emergency Medical Center between 1 April 2016 and 30 June 2022 was reviewed. After implementing universal RVVs, fewer children presented with RV-associated AGE (the reduction of proportion of the patients in 2022 was -61.7% (all ages), -57.9% (<1 years), -67.8% (1-<3 years), and -61.4% (3-<5 years) compared to 2019). A similar decrease in those of age who were not covered by the universal RVV was observed. There was a significant decline in the number of patients with AGE during the RV season who presented to the emergency department after implementing universal RVVs.

Full genotype constellations analysis of unusual DS-1-like G12P[6] and G6P[8] rotavirus strains detected in Brazil, 2019

Rotavirus A (RVA) is a major cause of acute gastroenteritis (AGE) in children worldwide. We report unusual RVA G12P[6] and G6P[8] strains isolated from fecal samples from Brazilian children hospitalized for AGE. The characterized RVA have genome segments backbone: G12-P[6]/ G6-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2 of DS-1-like genogroup. Our study describes the first identification of G6P[8], a DS-1-like genogroup strain. Nucleotide analysis of VP7 and VP4 genes revealed that all G12 Brazilian strains clustered into the sub-lineages IIIB, mostly associated with P[6] lineage I. Additionally, our G6 lineage I strains were closely related to German G6 genotypes, bound with P[8] lineage III, differing from both vaccine strains. The comparative sequence analysis of our strains with vaccine strains revealed amino acid substitutions located in immunodominant regions of VP7 and VP4 proteins. Continuous monitoring of RVA genotypes is essential to evaluate the impact of vaccination on the dynamic nature of RVA evolution.

Seasonal prevalence of potentially infectious enteric viruses in surface waters below treated wastewater discharge.

Enteric viruses are widely distributed in the natural water environment. The aim of the study was to assess the prevalence of potentially infectious adenoviruses (AdV) and rotaviruses (RoV) in surface water near treated wastewater discharge. Water samples were collected from surface water below the treated wastewater effluent discharge located near a wastewater treatment plant receiving sewage from an urban area. Water samples were concentrated by ultrafiltration and treated with propidium monoazide dye, followed with v-qPCR/v-RT-qPCR analysis. Simultaneously, the temperature and pH of the collected samples were measured to check the influence of these parameters on the concentrations of potentially infectious viruses. The average concentrations of potentially infectious AdV and RoV particles in collected samples ranged between log10 1.86 ÷ 3.94 gc/L and log10 2.39 ÷ 3.82 gc/L in the winter season, and between log10 2.18 ÷ 3.59 gc/L and log10 1.85 ÷ 2.10 gc/L in the summer season, respectively. In general, AdVs were detected more often than RoVs, while RoV-positive samples were more frequent in the winter than in the summer season (Chi2: p = 0.028; Fisher's Exact test p = 0.033). Negative correlations between log10 concentration of viral particles and temperature and pH for both viruses were observed. The presence of potentially infectious AdVs and RoVs in the surface waters may constitute a health risk for the local population. Application of v-PCR-based methods and considering AdV as a viral contamination indicator should be introduced into virological water quality monitoring for estimations of public health risks.

Detection and Molecular Characterization of Rotavirus Infections in Children and Adults with Gastroenteritis from Vojvodina, Serbia.

Rotaviruses (RV) are the leading cause of gastroenteritis in infants, young children, and adults, responsible for serious disease burden. In the period 2012–2018, a cross-sectional study was conducted using stool samples collected from patients with acute gastroenteritis from Vojvodina, Serbia. We described age and gender distribution, as well as seasonal patterns of RV prevalence. Out of 1853 included stool samples, RV was detected in 29%. Hospitalized children between 1–2 years old were especially affected by RV infection (45%). The highest prevalence of infection was observed during the colder, winter/spring months. We compared sequenced representative G and P genotypes circulating in Serbia with vaccine strains and determined their genetic similarity. Genotype combination G2P[4] was the most prevalent (34.6%), followed by G2P[8] (24.1%) and G1P[8] (21.1%). Given that several epitopes were conserved, neutralization motifs among circulating strains can be characterized as sufficiently matching vaccine strains Rotarix™ and RotaTeq™, but existing antigenic disparities should not be overlooked. The present results contribute to a better insight into the prevalence of rotavirus infection in our region and point out the need for epidemiological surveillance of rotaviruses before the introduction of vaccines. These data can help formulate future vaccine strategies in Serbia.

Antibody Response to Rotavirus C Pre-Farrow Natural Planned Exposure to Gilts and Their Piglets.

A longitudinal study was conducted to investigate the dynamics of genotype-specific (G6 and P[5]) antibody response to different doses (3, 2 and 1) of rotavirus C (RVC) natural planned exposure (NPE) in gilt serum, colostrum/milk and piglet serum, and compare with antibody response to rotavirus A NPE (RVA genotypes G4, G5, P[7] and P[23]). G6 and P[5] antigens of RVC were expressed in mammalian and bacterial cells, and used to develop individual indirect ELISAs. For both antigens, group 1 with 3 doses of NPE resulted in significantly higher IgG and IgA levels in colostrum compared to other groups. In piglet serum, group 1 P[5] IgG levels were significantly higher than other study groups at day 0 and 7. Piglet serum had higher IgA levels for group 1 piglets compared to other groups for both antigens. A comparison of colostrum antibody levels to rotavirus A (RVA) and RVC revealed that colostrum RVC IgG and IgA titers were lower than RVA titers irrespective of the G and P-type. Next generation sequencing (NGS) detected same RVC genotypes (G6 and P[5]) circulating in the piglet population under the window of lactogenic immunity. We conclude that the low RVC load in NPE material (real-time PCR Ct-values 32.55, 29.32 and 30.30) failed to induce sufficient maternal immunity in gilts (low colostrum RVC antibody levels) and passively prevent piglets from natural RVC infection in the farrowing room. To the best of our knowledge, this is the first study comparing differences in antibody response to porcine RVA and RVC in a commercial setting.

Glycan-mediated interactions between bacteria, rotavirus and the host cells provide an additional mechanism of antiviral defence.

Limited efficacy of rotavirus (RV) vaccines in children in developing countries and in animals remains a significant problem necessitating further search for additional approaches to control RV-associated gastroenteritis. During cell attachment and entry events, RV interacts with cell surface O-glycans including histo-blood group antigens (HBGAs). Besides modulation of the protective immunity against RV, several commensal and probiotic bacteria were shown to express HBGA-like substances suggesting that they may affect RV attachment and entry into the host cells. Moreover, some beneficial bacteria have been shown to possess the ability to bind host HBGAs via sugar specific proteins called lectins. However, limited research has been done to evaluate the effects of HBGA-expressing and/or HBGA-binding bacteria on RV infection. The aim of this study was to investigate the ability of selected commensal and probiotic bacteria to bind different RV strains via HBGAs and to block RV infection of IPEC-J2 cells. Our data indicated that Gram-negative probiotic Escherichia coli Nissle 1917 (E. coli Nissle 1917) and commensal Gram-positive (Streptococcus bovis and Bifidobacterium adolescentis) and Gram-negative (Bacteroides thetaiotaomicron, Clostridium clostridioforme and Escherichia coli G58 (E. coli G58) bacteria of swine origin expressed HBGAs which correlated with their ability to bind group A and C RVs. Additionally, Gram-positive E. coli 1917 and E. coli G58 demonstrated the ability to block RV attachment onto IPEC-J2 cells. Taken together, our results support the hypothesis that physical interactions between RVs and HBGA-expressing beneficial bacteria may limit RV replication.

Rotavirus Quantification in Children with Acute Gastroenteritis

Introduction: Most intractable diarrheas are treated with antibiotics, irrespective of the causative agent. This study aimed to quantify rotavirus (RV) with TaqMan real-time PCR in fecal samples of children with acute gastroenteritis (AGE) in accordance with the program of reduction of drug resistance and use of antibiotics. Methods: A total of 190 fecal specimens were collected from under-5-year-old children with AGE in pediatric Hospital Regina Margherita of Turin in Italy in 2017. A total of 38 out of 67 (56.7%) episodes of AGE were associated with RV genomic detection with a multiplex commercial kit. Results: All fecal specimens were tested for the presence of RV and other GE viruses. The most commonly detected virus was norovirus (41%), astrovirus (15.8%), human bocavirus (8.9%), sapovirus (7.9%), human parechovirus (5.8%), rhinovirus (4.2%), and adenovirus (1%). In 66 out of 190 (34.7%), RV was detectable with the median viral load 7.2E + 11 ± 60E + 11 genomes/mg fecal specimens. Discussion/Conclusions: Our results showed that RV was present in around 34.7% of children hospitalized for AGE, a rate similar to those reported in previous studies conducted elsewhere which were in the range of 33–75%. Our protocols are able to quantify the absolute number of viral particle/mg of feces. The clinical utility of quantitative molecular assays, such as RV viral load, will be markedly improved.

Molecular characterisation of a novel avian rotavirus A strain detected from a gull species (Larus sp.).

A recent study demonstrated the possibility that migratory birds are responsible for the global spread of avian rotavirus A (RVA). However, little is known about what types of RVAs are retained in migratory birds. In this study, to obtain information on RVA strains in migratory birds, we characterised an RVA strain, Ho374, that was detected in a faecal sample from a gull species (Larus sp.). Genetic analysis revealed that all 11 genes of this strain were classified as new genotypes (G28-P[39]-I21-R14-C14-M13-A24-N14-T16-E21-H16). This clearly indicates that the genetic diversity of avian RVAs is greater than previously recognised. Our findings highlight the need for investigations of RVA strains retained in migratory birds, including gulls.

Visual and Rapid Detection of Porcine Epidemic Diarrhea Virus (PEDV) Using Reverse Transcription Loop-Mediated Isothermal Amplification Method.

Simple SummaryPorcine epidemic diarrhea (PED) is a severe disease which has led to tremendous economic losses in the swine industry all over the world. The early detection of its pathogen (PEDV) is vital to prevent and cure this disease. Here, we report the development of a new visual diagnostic test for PEDV—the reverse transcription loop-mediated isothermal amplification (RT-LAMP) method. This new assay proved to be specific and sensitive when applied to clinical specimens.Porcine epidemic diarrhea virus (PEDV) can cause severe infectious porcine epidemic diarrhea (PED) and infect different ages of pigs, resulting in sickness and death among suckling pigs. For PEDV detection, finding an effective and rapid method is a priority. In this study, we established an effective reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for PEDV detection. Three sets of primers, specific for eight different sequences of the PEDV N gene, were designed in this study. The optimized RT-LAMP amplification program was as follows: 59 min at 61.9 °C and 3 min at 80 °C. The RT-LAMP results were confirmed with the addition of SYBR Green I fluorescence dye and with the detection of a ladder-like band by conventional gel electrophoresis analysis, which demonstrated a significant agreement between the two methods. The LOD of PEDV by RT-LAMP was 0.0001 ng/μL. Compared with RT-LAMP, the traditional RT-PCR method is 100-fold less sensitive. The RT-LAMP results had no cross-reaction with porcine parvovirus (PPV), porcine circovirus type 1 (PCV1), porcine pseudorabies virus (PRV), porcine circovirus type 2 (PCV2), rotavirus (RV), transmissible gastroenteritis virus (TGEV) and porcine reproductive and respiratory syndrome virus (PRRSV). Consequently, the newly developed RT-LAMP method could provide an accurate and reliable tool for PEDV diagnosis.

Assessment of rotavirus and norovirus emitted from water spray park: QMRA, diseases burden and sensitivity analysis

A quantitative model on exposure to pathogenic viruses in air of recreational area and their corresponding health effects is necessary to provide mitigation actions in content of emergency response plans (ERP). Here, the health risk associated with exposure to two pathogenic viruses of concern: Rotavirus (RoV) and Norovirus (NoV) in air of water spray park were estimated using a quantitative microbial risk assessment (QMRA) model. To this end, real-time Reverse Transcriptase polymerase chain reaction (real-time RT-PCR) was employed to measure the concentration levels of RoV and NoV over a twelve-month period. The probability of infection, illness and diseases burden of gastrointestinal illness (GI) caused by RoV and NoV for both workers and visitors were estimated using QMRA and Monto-Carlo simulation technique. The annual mean concentration for RoV and NoV in sampling air of water spray park were 20and 1754, respectively. The %95 confidence interval (CI) calculated annual DALY indicator for RoV (Workers: 2.62 × 10−4–2.62 × 10−1, Visitors: 1.50 × 10−5–2.42 × 10−1) and NoV (Workers: 5.54 × 10−3–2.53 × 10−1; Visitors: 5.18 × 10−4–2.54 × 10−1) were significantly higher the recommended values by WHO and US EPA (10−6–10−4 DALY pppy). According to sensitivity analysis, exposure dose and disease burden per case (DBPC) were found as the most influencing factors on disease burden as a consequences of exposure to RoV and NoV, respectively. The comprehensive information on DALY and QMRA can aid authorities involved in risk assessment and recreational actions to adopt proper approach and mitigation actions to minimize the health risk.

One-Year Surveillance of SARS-CoV-2 and Rotavirus in Water Matrices from a Hot Spring Area.

The pandemic of Coronavirus Disease 2019 (COVID-19) caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is still impacting not only on human health but also all economic activities, especially in those related to tourism. In this study, in order to characterize the presence of SARS-CoV-2 in a hot spring park in Uruguay, swimming pools water, wastewater, and surface water from this area were analyzed by quantitative PCR. Wastewater from Salto city located next to the hydrothermal spring area was also evaluated as well as the presence of Rotavirus (RV). Overall, SARS-CoV-2 was detected in 13% (13/102) of the analyzed samples. Moreover, this virus was not detected in any of the samples from the swimming pools water and was present in 18% (3/17) of wastewater samples from the hotels area showing the same trend between the titer of SARS-CoV-2 and the number of infected people in Salto city. SARS-CoV-2 was also detected in wastewater samples (32% (11/34)) from Salto city, detecting the first positive sample when 105 persons were positive for SARS-CoV-2. Rotavirus was detected only in 10% (2/24) of the wastewater samples analyzed in months when partial lockdown measures were taken, however, this virus was detected in nearly all wastewater samples analyzed when social distancing measures and partial lockdown were relaxed. Wastewater results confirmed the advantages of using the detection and quantification of viruses in this matrix in order to evaluate the presence of these viruses in the population, highlighting the usefulness of this approach to define and apply social distancing. This study suggests that waters from swimming pools are not a source of infection for SARS-CoV-2, although more studies are needed including infectivity assays in order to confirm this statement.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12560-022-09537-w.

Circulating rotavirus P[8]-lineage IV, unlike P[8]-lineage III, significantly related to nonsecretors status in Iranian children.

Rotavirus (RV) P[8] strains are responsible for the most of the RV infections globally and are significantly associated with the secretor and Lewis positive status. Among the distinct P[8] lineages, different ligand affinities have been detected which can be linked to differences in secretor status associated histo-blood group antigens (HBGAs).Herein, we report the lineages of P[8] strains and their associated secretor and Lewis antigen phenotypes in Iranian children. The phylogenetic tree and sequence analyses showed that the most common detected RV P[8] strain belonged to P[8]-lineage III (92%) and were significantly associated with secretor and Lewis positive status. In contrast, 8% of P[8] strains clustered into the P[8]-lineage IV and were significantly associated with nonsecretor status, implying that lineage IV tends to infect nonsecretor individuals. Furthermore, protein modeling and amino acid analyses of the VP8* glycan binding site of Iranian P[8]-lineage IV strains indicated two residual substitutions (T184V and N216V/I) compared to the P[8]-lineage III strains that might have affected the glycan affinity among P[8]-lineages IV strains. The corresponding residual changes might permit their continued transmission in nonsecretor children in competition with other P[8]-lineages. Although nonsecretors show natural resistant to P[8] strains, but such residual changes might overcome this natural resistance which in turn might indirectly contribute to the decline in the vaccine efficacy in populations where HBGA polymorphism allows their circulation at high frequency.

Rotavirus C infections in asymptomatic piglets in India, 2009-2013: genotyping and phylogenetic analysis of all genomic segments.

Asymptomatic infection with rotavirus C (RVC) was observed in pigs in India, with a detection rate of 20%. Sequencing of the VP6, VP7, and NSP4 genes of RVC strains identified the genotypes I7/I10, G1, and E5, respectively. Full genome sequencing of one of these strains revealed that the genotypes of the VP4, VP1, VP2, VP3, NSP1, NSP2, NSP3, and NSP5 genes were P1, R1, C1, M3, A1, N5, T5, and H1, respectively. The detection of porcine RVC strains at two different locations in India at different time points strongly suggests that they are circulating continuously in the pig population through asymptomatic infections.

Rotavirus Infection in Swine: Genotypic Diversity, Immune Responses, and Role of Gut Microbiome in Rotavirus Immunity.

Rotaviruses (RVs) are endemic in swine populations, and all swine herds certainly have a history of RV infection and circulation. Rotavirus A (RVA) and C (RVC) are the most common among all RV species reported in swine. RVA was considered most prevalent and pathogenic in swine; however, RVC has been emerging as a significant cause of enteritis in newborn piglets. RV eradication from swine herds is not practically achievable, hence producers’ mainly focus on minimizing the production impact of RV infections by reducing mortality and diarrhea. Since no intra-uterine passage of immunoglobulins occur in swine during gestation, newborn piglets are highly susceptible to RV infection at birth. Boosting lactogenic immunity in gilts by using vaccines and natural planned exposure (NPE) is currently the only way to prevent RV infections in piglets. RVs are highly diverse and multiple RV species have been reported from swine, which also contributes to the difficulties in preventing RV diarrhea in swine herds. Human RV-gut microbiome studies support a link between microbiome composition and oral RV immunogenicity. Such information is completely lacking for RVs in swine. It is not known how RV infection affects the functionality or structure of gut microbiome in swine. In this review, we provide a detailed overview of genotypic diversity of swine RVs, host-ranges, innate and adaptive immune responses to RVs, homotypic and heterotypic immunity to RVs, current methods used for RV management in swine herds, role of maternal immunity in piglet protection, and prospects of investigating swine gut microbiota in providing immunity against rotaviruses.

Seroprevalence of Anti-tTg-IgA among Symptomized Celiac Disease Patients and Their Correlation with Rotavirus Infection.

Celiac disease (CD) is a chronic inflammatory disorder in the intestinal tract as a response to the use of gluten in genetically predisposed individuals. It is a worldwide problem, with a high prevalence rate in North America. This is a descriptive cross-sectional study involving 1090 samples collected from different hospitals of Rawalpindi and Islamabad, Pakistan, from January 2019 to December 2019. In this study, 1090 blood samples screened for seroprevalence of anti-tTG antibodies in CD symptomatic patients via ELISA (enzyme-linked immunosorbent assay). 1090 fecal samples from the same CD patients were collected and tested for the presence of rotavirus (RV) via ELISA and RT-PCR. Of the 1090 patients tested for seroprevalence of anti-tTG antibodies, 112/1090 (10.3%) were found to be positive. Of the 112 anti-tTG-positive patients, 78/112 (70%) were positive for RV via ELISA and 74/112 (66.1%) were RV positive via RT-PCR. A statistically significant association was reported between rotavirus infection and celiac disease (p˂0.05). Anti-tTG antibodies were higher in age group 6 (12-18 years) patients (18.4%) and at minimum in age group 3 (1-3 years) patients (4.8%). However, there was a statistically insignificant relationship between group age and CD prevalence (p > 0.05). The highest CD prevalence was noted during winter season (19.6%) and the lowest (3.0%) during fall/autumn. Our study findings demonstrate that Pakistan has a high prevalence of CD compared to other studies. Further studies in the fields of environmental risk factors and treatment with more advanced serological and histopathological studies are needed in the future.

Generation and characterization of mouse monoclonal antibodies against the VP4 protein of group A human rotaviruses

Human rotaviruses (RVs) are the leading cause of severe diarrhea in infants and young children worldwide. Among the structural proteins, as a spike protein, rotavirus VP4 plays a key role in both viral attachment and penetration. Currently, studies on monoclonal antibodies (mAbs) against VP4 are limited. In this study, mice were immunized with truncated VP4* to produce murine mAbs. In total, 50 mAbs were produced and characterized. Twenty-four mAbs were genotype-specific and 20 mAbs recognized the common VP4 epitopes shared by P[8], P[4], and P[6] viruses. Thirty-five of the 50 mAbs were neutralizing mAbs, among which nine mAbs could neutralize all three P-genotype RVs, and 10 neutralizing mAbs exhibited conformational sensitivity. Ten mAbs recognized dominant neutralizing epitopes, including the broadly neutralizing mAb 9C4 recognized conformational epitope. Further investigation shows that S376 and S464 are key amino acids for 9C4 binding, however, the exact binding sites of 9C4 remain to be fully defined. Overall, this panel of mAbs has demonstrated utility as immunodiagnostic and research reagents, and could potentially serve as crucial tools for exploring the neutralizing mechanisms and quality control of VP4* protein-based RV subunit vaccines. Further evaluation of cross-neutralizing mAbs could not only improve the understanding of the heterotypic protection conferred by RV vaccines, but also facilitate the development of broadly protective RV vaccines.

Genomic and evolutionary characteristics of G9P[8], the dominant group a rotavirus in China (2016-2018).

G9P[8] became the predominant rotavirus A (RVA) genotype in China in 2012. To evaluate its genetic composition at the whole-genome level, 115 G9P[8] RVA strains isolated from children under 5 years old were sequenced and characterized. All 13 strains in 2016 and 2017 and an additional 54 strains in 2018 were genotyped as G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. The other 48 strains in 2018 were all genotyped as G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E2-H1, with the NSP4 gene characterized as a DS-1-like genotype. The time of the most recent common ancestor (tMRCA) and evolution rates of the VP7, VP4, and NSP4 (E1 and E2) genes of these strains were estimated by Bayesian evolutionary dynamics analysis. We estimated the evolution rates (nt substitutions per site per year) as 1.38 × 10–3 [the 95% highest posterior density (HPD) was 1.09–1.72 × 10–3] for VP7, 0.87 × 10–3 (95% HPD: 0.75–1.00 × 10–3) for VP4, 0.56 × 10–3 (95% HPD: 0.41–0.73 × 10–3) for NSP4-E1, and 1.35 × 10–3 (95% HPD: 0.92–1.86 × 10–3) for NSP4-E2. The tMRCA was estimated to be 1935.4 (95% HPD: 1892.4–1961.3) for VP7, 1894.3 (95% HPD: 1850.5–1937.8) for VP4, 1929.4 (95% HPD: 1892.4–1961.3) for NSP4-E1, and 1969.2 (95% HPD: 1942.2–1985.3) for NSP4-E2. The baseline genetic information in this study is expected to improve our understanding of the genomic and evolutionary characteristics of the rotavirus genome. Furthermore, it will provide a basis for the development of next-generation rotavirus vaccines for humans.

Sneaking into the viral safe-houses: Implications of host components in regulating integrity and dynamics of rotaviral replication factories.

The biology of the viral life cycle essentially includes two structural and functional entities—the viral genome and protein machinery constituting the viral arsenal and an array of host cellular components which the virus closely associates with—to ensure successful perpetuation. The obligatory requirements of the virus to selectively evade specific host cellular factors while exploiting certain others have been immensely important to provide the platform for designing host-directed antiviral therapeutics. Although the spectrum of host-virus interaction is multifaceted, host factors that particularly influence viral replication have immense therapeutic importance. During lytic proliferation, viruses usually form replication factories which are specialized subcellular structures made up of viral proteins and replicating nucleic acids. These viral niches remain distinct from the rest of the cellular milieu, but they effectively allow spatial proximity to selective host determinants. Here, we will focus on the interaction between the replication compartments of a double stranded RNA virus rotavirus (RV) and the host cellular determinants of infection. RV, a diarrheagenic virus infecting young animals and children, forms replication bodies termed viroplasms within the host cell cytoplasm. Importantly, viroplasms also serve as the site for transcription and early morphogenesis of RVs and are very dynamic in nature. Despite advances in the understanding of RV components that constitute the viroplasmic architecture, knowledge of the contribution of host determinants to viroplasm dynamicity has remained limited. Emerging evidence suggests that selective host determinants are sequestered inside or translocated adjacent to the RV viroplasms. Functional implications of such host cellular reprogramming are also ramifying—disarming the antiviral host determinants and usurping the pro-viral components to facilitate specific stages of the viral life cycle. Here, we will provide a critical update on the wide variety of host cellular pathways that have been reported to regulate the spatial and temporal dynamicity of RV viroplasms. We will also discuss the methods used so far to study the host-viroplasm interactions and emphasize on the potential host factors which can be targeted for therapeutic intervention in the future.

Rotavirus A in Domestic Pigs and Wild Boars: High Genetic Diversity and Interspecies Transmission.

Rotavirus A (RVA) is an important pathogen for porcine health. In comparison to humans, RVA in domestic animals and especially in wildlife is under researched. Therefore, the aim of the present study was to investigate the prevalence, genetic diversity, molecular epidemiology and interspecies transmission of RVA in domestic pigs and wild boars. During the three consecutive RVA seasons (2018–2021) we collected 445 and 441 samples from domestic pigs and wild boars, respectively. Samples were tested by real-time RT-PCR, and RVA-positive samples were genotyped in VP7 and VP4 segments. Our results report an RVA prevalence of 49.9% in domestic pigs and 9.3% in wild boars. Outstanding RVA genetic diversity was observed in VP7 and VP4 segments, especially in domestic pigs exhibiting a striking 23 different RVA combinations (G5P[13] and G9P[23] prevailed). Interspecies transmission events were numerous between domestic pigs and wild boars, sharing G3, G5, G6, G9, G11 and P[13] genotypes. Furthermore, our data indicate that such transmission events involved even bovines (G6, P[11]) and, intriguingly, humans (G1P[8]). This study contributes to the basic knowledge that may be considered important for vaccine development and introduction, as a valuable and currently missing tool for efficient pig health management in the EU.