Search Results (46)

This review synthesizes current knowledge on the risks posed by viral foodborne infections associated with pork, emphasizing their global prevalence and the complexity of managing such pathogens. It covers a range of significant viruses, including hepatitis A and E, norovirus, rotavirus, sapovirus, enterovirus, astrovirus, and enteric adenovirus. The role of pigs as reservoirs for diverse pathogens with zoonotic potential further complicates safety challenges, extending risks to individuals involved in pork production and processing. Various factors influencing viral contamination throughout the meat production chain are explored, from farm-level practices to processing and handling procedures. Emphasis is placed on the critical importance of implementing effective control measures at each stage, including enhanced biosecurity, rigorous hygiene practices, and appropriate thermal processing techniques. Additionally, the need for improved surveillance and detection methods to effectively identify and monitor viral presence in meat products is highlighted. In conclusion, the necessity of adopting a One Health approach that integrates efforts in animal health, food safety, and public health to mitigate the risks of viral foodborne infections associated with meat consumption is underscored. This holistic strategy is essential for safeguarding consumer health and ensuring the safety of the global food supply. Full article

An intrinsically disordered protein (IDP) or region (IDR) lacks or has little protein structure but still maintains function. This lack of structure creates flexibility and fluidity, allowing multiple protein conformations and potentially transient interactions with more than one partner. Caliciviruses are positive-sense ssRNA viruses, containing a relatively small genome of 7.6–8.6 kb and have a broad host range. Many viral proteins are known to contain IDRs, which benefit smaller viral genomes by expanding the functional proteome through the multifunctional nature of the IDR. The percentage of intrinsically disordered residues within the total proteome for each calicivirus type species can range between 8 and 23%, and IDRs have been experimentally identified in NS1-2, VPg and RdRP proteins. The IDRs within a protein are not well conserved across the genera, and whether this correlates to different activities or increased tolerance to mutations, driving virus adaptation to new selection pressures, is unknown. The function of norovirus NS1-2 has not yet been fully elucidated but includes involvement in host cell tropism, the promotion of viral spread and the suppression of host interferon-λ responses. These functions and the presence of host cell-like linear motifs that interact with host cell caspases and VAPA/B are all found or affected by the disordered region of norovirus NS1-2. The IDRs of calicivirus VPg are involved in viral transcription and translation, RNA binding, nucleotidylylation and cell cycle arrest, and the N-terminal IDR within the human norovirus RdRP could potentially drive liquid–liquid phase separation. This review identifies and summarises the IDRs of proteins within the Caliciviridae family and their importance during viral replication and subsequent host interactions. Full article

Enteric viruses are the leading cause of diarrhoea in children <5 years. Despite existing studies describing rotavirus diarrhoea in Mozambique, data on other enteric viruses remains scarce, especially after rotavirus vaccine introduction. We explored the prevalence of norovirus GI and GII, adenovirus 40/41, astrovirus, and sapovirus in children <5 years with moderate-to-severe (MSD), less severe (LSD) diarrhoea and community healthy controls, before (2008–2012) and after (2016–2019) rotavirus vaccine introduction in Manhiça District, Mozambique. The viruses were detected using ELISA and conventional reverse transcription PCR from stool samples. Overall, all of the viruses except norovirus GI were significantly more detected after rotavirus vaccine introduction compared to the period before vaccine introduction: norovirus GII in MSD (13/195, 6.7% vs. 24/886, 2.7%, respectively; p = 0.006) and LSD (25/268, 9.3% vs. 9/430, 2.1%, p < 0.001); adenovirus 40/41 in MSD (7.2% vs. 1.8%, p < 0.001); astrovirus in LSD (7.5% vs. 2.6%, p = 0.002); and sapovirus in MSD (7.1% vs. 1.4%, p = 0.047) and controls (21/475, 4.4% vs. 51/2380, 2.1%, p = 0.004). Norovirus GII, adenovirus 40/41, astrovirus, and sapovirus detection increased in MSD and LSD cases after rotavirus vaccine introduction, supporting the need for continued molecular surveillance for the implementation of appropriate control and prevention measures. Full article

We investigated the occurrence of eight potential zoonotic viruses in 91 exotic companion mammals from pet shops in southern Italy via real-time PCR and end-point PCR. The animals were screened for aichivirus, sapovirus, astrovirus, hepatitis A, noroviruses (GI and GII), rotavirus, circovirus, and SARS-CoV-2. Among the nine species of exotic pets studied, only one rat tested positive for aichivirus. The high sequence similarity to a murine kobuvirus-1 strain previously identified in China suggests that the virus may have been introduced into Italy through the importation of animals from Asia. Since exotic companion mammals live in close contact with humans, continuous sanitary monitoring is crucial to prevent the spread of new pathogens among domestic animals and humans. Further investigations on detecting and typing zoonotic viruses are needed to identify emerging and re-emerging viruses to safeguard public health. Full article

Using a metagenomic sequencing approach on stool samples from children with Acute Flaccid Paralysis (AFP), we describe the genetic diversity of Sapoviruses (SaVs) in children in Nigeria. We identified six complete genome sequences and two partial genome sequences. Several SaV genogroups and genotypes were detected, including GII (GII.4 and GII.8), GIV (GIV.1), and GI (GI.2 and GI.7). To our knowledge, this is the first description of SaV infections and complete genomes from Nigeria. Pairwise identity and phylogenetic analysis showed that the Nigerian SaVs were related to previously documented gastroenteritis outbreaks with associated strains from China and Japan. Minor variations in the functional motifs of the nonstructural proteins NS3 and NS5 were seen in the Nigerian strains. To adequately understand the effect of such amino acid changes, a better understanding of the biological function of these proteins is vital. The identification of distinct SaVs reinforces the need for robust surveillance in acute gastroenteritis (AGE) and non-AGE cohorts to better understand SaVs genotype diversity, evolution, and its role in disease burden in Nigeria. Future studies in different populations are, therefore, recommended. Full article

Porcine sapovirus (PoSaV) is one of the most significant pathogens causing piglet diarrhea, and one with limited genetic characterization. In this study, the prevalence, infection pattern, and genetic evolution of porcine sapovirus were elucidated in detail. The positive rate of PoSaV was 10.1% (20/198), with dual, triple, and quadruple infections of 45%, 40%, and 5%, respectively. To further explore the viral composition in the PoSaV-positive diarrhea feces, metagenomic sequencing was carried out. The results confirmed that RNA viruses accounted for a higher proportion (55.47%), including the two primary viruses of PoSaV (21.78%) and porcine astrovirus (PAstV) (24.54%) in the tested diarrhea feces samples. Afterward, a full-length sequence of the PoSaV isolate was amplified and named SHCM/Mega2023, and also given the identifier of GenBank No. PP388958. Phylogenetic analysis identified the prevalent PoSaV strain SHCM/Mega2023 in the GIII genogroup, involving a recombinant event with MK962338 and KT922089, with the breakpoint at 2969–5132 nucleotides (nt). The time tree revealed that the GIII genogroup exhibits the widest divergence time span, indicating a high likelihood of viral recombination. Moreover, SHCM/Mega2023 had three nucleotide “RPL” insertions at the 151–153 nt site in the VP2 gene, compared to the other GIII strains. Further selective pressure calculations demonstrate that the whole genome of the SHCM/Mega2023 strain was under purifying selection (dN/dS < 1), with seven positively selected sites in the VP1 protein, which might be related to antigenicity. In conclusion, this study presents a novel genomic evolution of PoSaV, offering valuable insights into antigenicity and for vaccine research. Full article

This study investigated the prevalence and genetic diversity of gastroenteric viruses in mussels and oysters in Rio de Janeiro, Brazil. One hundred and thirty-four marketed bivalve samples were obtained between January and December 2022. The viral analysis was performed according to ISO/TS 15216, and the screening revealed the detection of norovirus GII/GI (40.3%), sapovirus (SaV; 12.7%), human mastadenovirus (7.5%), and rotavirus A (RVA; 5.9%). In total, 44.8% (60) of shellfish samples tested positive for one or more viruses, 46.7% (28/60) of the positive samples tested positive for a single viral agent, 26.7% (16) tested positive for two viral agents, 8.3% (5) for three viral agents, and 13.3% (8) for four viral agents. Additionally, three mussel samples were contaminated with the five investigated viruses (5%, 3/60). Norovirus GII showed the highest mean viral load (3.4 × 10⁵ GC/g), followed by SaV (1.4 × 10⁴ GC/g), RVA (1.1 × 10⁴ GC/g), human mastadenovirus (3.9 × 10³ GC/g), and norovirus GI (6.7 × 10² GC/g). Molecular characterization revealed that the recovered norovirus strains belonged to genotypes GII.2, GII.6, GII.9, GII.17, and GII.27; SaV belonged to genotypes GI.1 and GIV.1; RVA to genotypes G6, G8, P[8]-III, and human mastadenovirus to types F40 and F41. The GII.27 norovirus characterized in this study is the only strain of this genotype reported in Brazil. This study highlights the dissemination and diversity of gastroenteric viruses present in commercialized bivalves in a touristic area, indicating the potential risk to human health and the contribution of bivalves in the propagation of emerging pathogens. Full article

Human sapoviruses (HuSaVs) and noroviruses are considered the leading cause of acute gastroenteritis worldwide. While extensive research has focused on noroviruses, our understanding of sapoviruses (SaVs) and their interactions with the host’s immune response remains limited. HuSaVs have been challenging to propagate in vitro, making the porcine sapovirus (PSaV) Cowden strain a valuable model for studying SaV pathogenesis. In this study we show, for the first time, that PSaV Cowden strain has mechanisms to evade the host’s innate immune response. The virus 3C-like protease (NS6) inhibits type I IFN production by targeting TBK1. Catalytically active NS6, both during ectopic expression and during PSaV infection, targets TBK1 which is then led for rapid degradation by the proteasome. Moreover, deletion of TBK1 from porcine cells led to an increase in PSaV titres, emphasizing its role in regulating PSaV infection. Additionally, we successfully established PSaV infection in IPEC-J2 cells, an enterocytic cell line originating from the jejunum of a neonatal piglet. Overall, this study provides novel insights into PSaV evasion strategies, opening the way for future investigations into SaV–host interactions, and enabling the use of a new cell line model for PSaV research. Full article

Human viruses and viruses from animals can cause illnesses in humans after the consumption of contaminated food or water. Contamination may occur during preparation by infected food handlers, during food production because of unsuitably controlled working conditions, or following the consumption of animal-based foods contaminated by a zoonotic virus. This review discussed the recent information available on the general and clinical characteristics of viruses, viral foodborne outbreaks and control strategies to prevent the viral contamination of food products and water. Viruses are responsible for the greatest number of illnesses from outbreaks caused by food, and risk assessment experts regard them as a high food safety priority. This concern is well founded, since a significant increase in viral foodborne outbreaks has occurred over the past 20 years. Norovirus, hepatitis A and E viruses, rotavirus, astrovirus, adenovirus, and sapovirus are the major common viruses associated with water or foodborne illness outbreaks. It is also suspected that many human viruses including Aichi virus, Nipah virus, tick-borne encephalitis virus, H5N1 avian influenza viruses, and coronaviruses (SARS-CoV-1, SARS-CoV-2 and MERS-CoV) also have the potential to be transmitted via food products. It is evident that the adoption of strict hygienic food processing measures from farm to table is required to prevent viruses from contaminating our food. Full article

Sapovirus (SaV) is a type of gastroenteric virus that can cause acute gastroenteritis. It is highly contagious, particularly among children under the age of 5. In this study, a total of 712 stool samples from children under the age of 5 with acute gastroenteritis were collected. Out of these samples, 28 tested positive for SaV, resulting in a detection rate of 3.93% (28/712). Samples with Ct < 30 were collected for library construction and high-throughput sequencing, resulting in the acquisition of nine complete genomes. According to Blast, eight of them were identified as GI.1, while the remaining one was GI.6. The GI.6 strain sequence reported in our study represents the first submission of the GI.6 strain complete genome sequence from mainland China to the Genbank database, thus filling the data gap in our country. Sequence identity analysis revealed significant nucleotide variations between the two genotypes of SaV and their corresponding prototype strains. Phylogenetic and genetic evolution analyses showed no evidence of recombination events in the obtained sequences. Population dynamics analysis demonstrated potential competitive inhibition between two lineages of GI.1. Our study provides insights into the molecular epidemiological and genetic evolution characteristics of SaV prevalent in the Nantong region of China, laying the foundation for disease prevention and control, as well as pathogen tracing related to SaV in this area. Full article

Rotavirus (RV), norovirus (NoV), sapovirus (SaV), and human astrovirus (HAstV) are the most common viral causes of gastroenteritis in children worldwide. From 2016 to 2021, we conducted a cross-sectional descriptive study to determine the prevalence of these viruses in hospitalized children under five years old in Nam Dinh and Thua Thien Hue provinces in Vietnam during the pilot introduction of the RV vaccine, Rotavin-M1 (POLYVAC, Hanoi, Vietnam). We randomly selected 2317/6718 (34%) acute diarrheal samples from children <5 years of age enrolled at seven sentinel hospitals from December 2016 to May 2021; this period included one year surveillance pre-vaccination from December 2016 to November 2017. An ELISA kit (Premier Rotaclone^®, Meridian Bioscience, Inc., Cincinnati, OH, USA) was used to detect RV, and two multiplex real-time RT-PCR assays were used for the detection of NoV, SaV and HAstV. The prevalence of RV (single infection) was reduced from 41.6% to 22.7% (p < 0.0001) between pre- and post-vaccination periods, while the single NoV infection prevalence more than doubled from 8.8% to 21.8% (p < 0.0001). The SaV and HAstV prevalences slightly increased from 1.9% to 3.4% (p = 0.03) and 2.1% to 3.3% (p = 0.09), respectively, during the same period. Viral co-infections decreased from 7.2% to 6.0% (p = 0.24), mainly due to a reduction in RV infection. Among the genotypeable samples, NoV GII.4, SaV GI.1, and HAstV-1 were the dominant types, representing 57.3%, 32.1%, and 55.0% among the individual viral groups, respectively. As the prevalence of RV decreases following the national RV vaccine introduction in Vietnam, other viral pathogens account for a larger proportion of the remaining diarrhea burden and require continuing close monitoring. Full article

Sapoviruses, like noroviruses, are single-stranded positive-sense RNA viruses classified in the family Caliciviridae and are recognized as a causative pathogen of diarrhea in infants and the elderly. Like human norovirus, human sapovirus (HuSaV) has long been difficult to replicate in vitro. Recently, it has been reported that HuSaV can be replicated in vitro by using intestinal epithelial cells (IECs) derived from human tissues and cell lines derived from testicular and duodenal cancers. In this study, we report that multiple genotypes of HuSaV can sufficiently infect and replicate in human-induced pluripotent stem cell-derived IECs. We also show that this HuSaV replication system can be used to investigate the conditions for inactivation of HuSaV by heat and alcohol, and the effects of virus neutralization of antisera obtained by immunization with vaccine antigens, under conditions closer to the living environment. The results of this study confirm that HuSaV can also infect and replicate in human normal IECs regardless of their origin and are expected to contribute to future virological studies. Full article

Porcine sapovirus (PoSaV) has been reported in many countries over the world, which may cause gastroenteritis symptoms in pigs with all ages. There has been no report on PoSaV infection in Vietnam up to now. In this study, a total of 102 samples were collected from piglets, fattening pigs, and sows with diarrhea in several cities and provinces in northern Vietnam. The PoSaV genome was examined using polymerase chain reaction (PCR). Sequencing of the partial RNA-dependent RNA polymerase (RdRp) gene sequences (324 bp) was performed. Of the 102 tested samples, 10 (9.8%) and 7/20 (35%) were detected as positive for the PoSaV RdRp gene using the PCR method at the individual and farm levels, respectively. Genetic analysis of the partial RdRp gene region of about 324 bp indicated that the nucleotide identity of the current 10 Vietnamese viral strains ranged from 61.39% to 100%. Among the 10 strains obtained, 8 belonged to genotype III and the remaining 2 strains were clustered in genotype VIII. The Vietnamese genotype III viruses formed two sub-clusters. The Vietnamese PoSaV strains were closely related to PoSaVs reported in South Korea, Venezuela, and the Netherlands. This research was the first to describe PoSaV infection in northern Vietnam during 2022–2023. Full article

We devised a reverse genetics system to generate an infectious human sapovirus (HuSaV) GII.3 virus. Capped/uncapped full-length RNAs derived from HuSaV GII.3 AK11 strain generated by in vitro transcription were used to transfect HuTu80 human duodenum carcinoma cells; infectious viruses were recovered from the capped RNA-transfected cells and passaged in the cells. Genome-wide analyses indicated no nucleotide sequence change in the virus genomes in the cell-culture supernatants recovered from the transfection or those from the subsequent infection. No virus growth was detected in the uncapped RNA-transfected cells, suggesting that the 5′-cap structure is essential for the virus’ generation and replication. Two types of virus particles were purified from the cell-culture supernatant. The complete particles were 39.2-nm-dia., at 1.350 g/cm³ density; the empty particles were 42.2-nm-dia. at 1.286 g/cm³. Two proteins (58-kDa p58 and 17-kDa p17) were detected from the purified particles; their molecular weight were similar to those of VP1 (~60-kDa) and VP2 (~16-kDa) of AK11 strain deduced from their amino acids (aa) sequences. Protein p58 interacted with HuSaV GII.3-VP1-specific antiserum, suggesting that p58 is HuSaV VP1. A total of 94 (57%) aa of p17 were identified by mass spectrometry; the sequences were identical to those of VP2, indicating that the p17 is the VP2 of AK11. Our new method produced infectious HuSaVs and demonstrated that VP2 is the minor protein of the virion, suggested to be involved in the HuSaV assembly. Full article

Acute gastroenteritis (AGE) contributes to increased morbidity and mortality worldwide. In particular, children in resource-poor settings suffer from frequent episodes of diarrhea. A variety of pathogens, including bacteria, viruses, fungi, and protozoa, can cause AGE. Common viruses associated with AGE are norovirus, rotavirus, astrovirus, adenovirus, and sapovirus. Due to their similar clinical presentation, AGE pathogens cannot be distinguished on clinical grounds rendering the etiological diagnosis challenging. However, reliable diagnosis is essential for individual and public health reasons, e.g., to limit transmission, for appropriate antibiotic use, prognostic appreciation, and vaccination programs. Therefore, high-quality data derived by accurate diagnostics are important to improve global health. In Western industrialized countries, diagnosis relies on microbiological testing, including culture methods, microscopy, immunochromatography, and single-target molecular methods. Recently, multiplex PCR or syndromic panels have been introduced, which simultaneously analyze for multiple pathogens in a very short time. A further technological advancement is cartridge-based syndromic panels, which allow for near patient/point-of-care testing independently from a laboratory. In resource-poor tropical regions, however, laboratory diagnosis is rarely established, and there are little routine laboratory data on the epidemiology of viral AGE pathogens. Limiting factors for the implementation of syndromic panels are high costs, sophisticated equipment, and the need for trained personnel. In addition, pilot studies have shown a large number of viral (co-)detections among healthy controls, thus further challenging their clinical utilization. Hence, there are little evidence-based data on the impact of multiplex syndromic panels from resource-limited regions. Here, we aim to provide a brief overview of what is known about the use of syndromic panels for virus-associated AGE in tropical regions and to address future challenges. Full article