Rotavirus, a primary contributor to severe cases of infantile gastroenteritis on a global scale, results in significant morbidity and mortality in the under-five population, particularly in middle to low-income countries, including India. WHO-approved live-attenuated vaccines are linked to a heightened susceptibility to intussusception and exhibit low efficacy, primarily attributed to the high genetic diversity of rotavirus, varying over time and across different geographic regions. Herein, molecular data on Indian rotavirus A (RVA) has been reviewed through phylogenetic analysis, revealing G1P[8] to be the prevalent strain of RVA in India. The conserved capsid protein sequences of VP7, VP4 and VP6 were used to examine helper T lymphocyte, cytotoxic T lymphocyte and linear B cell epitopes. Twenty epitopes were identified after evaluation of factors such as antigenicity, non-allergenicity, non-toxicity, and stability. These epitopes were then interconnected using suitable linkers and an N-terminal beta defensin adjuvant. The in silico designed vaccine exhibited structural stability and interactions with integrins (αvβ3 and αIIbβ3) and toll-like receptors (TLR2 and TLR4) indicated by docking and normal mode analyses. The immune simulation profile of the designed RVA multiepitope vaccine exhibited its potential to trigger humoral as well as cell-mediated immunity, indicating that it is a promising immunogen. These computational findings indicate potential efficacy of the designed vaccine against rotavirus infection.

Objective: To investigate the association between intestinal colonization of segmented filamentous bacteria (SFB) and the risk of rotavirus infection, and the possible mechanisms by which SFB resist rotavirus infection. Methods: This case-control study enrolled 50 children aged 0 to 5 years who present to the outpatient Department of Children\'s Hospital, Zhejiang University School of Medicine with diarrhea and positive stool tests for rotavirus. The children were divided into rotavirus enteritis group and control group consisting of 55 children with non-gastrointestinal and non-infectious surgical diseases.The age and sex composition of the two groups was matched. The DNA of the fecal flora was extracted and SFB was detected by real-time fluorescence quantitative PCR analysis. The children in the rotavirus enteritis group and the control group were subgrouped by age and sex to analyze the differences in SFB positivity rates between different groups, and further compare and analyze the differences in SFB positivity rates between these two groups of children in the ≤2 years old subgroup and the >2-5 years old subgroup. Neutralization test was performed with p3340 protein and rotavirus to determine the relationship between rotavirus infection rate and p3340 concentration in Vero cells. χ2 test or Fisher\'s exact probability method was used for comparison between the two groups. Results: There were 50 children in the rotavirus enteritis group with an age of (1.7±0.9) years, and 55 children in the control group with an age of (1.8±1.1) years. The positive rate of SFB in children with rotavirus enteritis showed a declining trend across ages groups, with the highest rate of 10/14 in the ≤1 year old group, followed by 67% (14/21) in the >1-2 years old group, 9/15 in the >2-5 years old group, and there was no statistically significant difference (P=0.867). The positive rate of SFB in the control group was 12/15 in the ≤1 year old group, 95% (19/20) in the >1-2 years old group, 50% (10/20) in the >2-5 years old group, with statistical significance (P=0.004). The positive rate of SFB in children with rotavirus enteritis was 74% (20/27) in males and 56% (13/23) in females (χ2=1.71, P=0.192). In the control group, it was 79% (22/28) in males and 70% (19/27) in females (χ2=0.49, P=0.485). The positive rate of SFB was 66% (33/50) in the rotavirus enteritis group and 75% (41/55) in the control group, with no statistically significant (χ2=0.56, P=0.454). In the children ≤2 years old, the SFB positivity rate was 69% (24/35) in the rotavirus enteritis group and 89% (31/35) in the control group, with a statistically significant difference (χ2=4.16, P=0.041). However, in the children >2-5 years old, no statistically significant difference was observed, with the positive rate of SFB being 9/15 in the rotavirus enteritis group and 50% (10/20) in the control group (P=0.734). Pearson correlation analysis revealed a negative correlation between rotavirus infection and SFB positivity (r=-0.87,P<0.001). As the concentration of the p3340 specific protein increased, the luminescence intensity of the luciferase in the Vero cells, which were suitable for cultivating rotavirus, exhibited a decreasing trend (F=4.17, P=0.001). Conclusions: SFB colonization in infants less than 2 years old is associated with a reduced risk of rotavirus infection. Cloning of specific SFB functional protein p3340 neutralizes rotavirus infection of Vero cells, and this mechanism of targeting rotavirus infection differs from the common antiviral mechanism.
目的： 探讨肠道分节丝状菌（SFB）定植与轮状病毒感染风险的关系及SFB抵御轮状病毒感染的可能机制。 方法： 病例对照研究。选择在浙江大学医学院附属儿童医院门诊因腹泻经粪便检测轮状病毒阳性的0~5岁患儿50例为研究对象，即轮状病毒性肠炎组，并以非胃肠道疾病、非感染性疾病的外科疾病患儿55例为对照组，年龄、性别组成与轮状病毒性肠炎组相匹配。提取粪便菌群的DNA，通过实时荧光定量PCR分析测定SFB，将轮状病毒性肠炎组及对照组患儿分别按照年龄和性别分组，分析SFB的阳性率在不同组间的差异，并进一步比较分析这两组患儿在≤2岁组及>2~5岁年龄组SFB阳性率的差异。通过p3340蛋白与轮状病毒进行中和试验，确定Vero细胞轮状病毒感染率与p3340浓度之间的关系。组间比较采用χ2检验或Fisher确切概率法。 结果： 轮状病毒性肠炎组患儿50例，年龄（1.7±0.9）岁，对照组患儿55例，年龄（1.8±1.1）岁。轮状病毒性肠炎组患儿SFB 的阳性率在各个年龄中呈递减分布，其中≤1岁组最高，为10/14，>1~2岁组为67%（14/21），>2~5岁组为9/15，差异无统计学意义（P=0.867）；对照组患儿≤1岁组SFB阳性率为12/15，>1~2岁组为95%（19/20），>2~5岁组为50%（10/20），差异有统计学意义（P=0.004）。轮状病毒性肠炎组患儿男童SFB阳性率为74%（20/27），女童为56%（13/23），差异无统计学意义（χ2=1.71，P=0.192）；对照组患儿男童SFB阳性率为79%（22/28），女童为70%（19/27），差异无统计学意义（χ2=0.49，P=0.485）。轮状病毒性肠炎组SFB阳性率66%（33/50），对照组为75%（41/55），差异无统计学意义（χ2=0.56，P=0.454）。在≤2岁患儿中，轮状病毒性肠炎组SFB阳性率69%（24/35），对照组为89%（31/35），差异有统计学意义（χ2=4.16，P=0.041）；在>2~5岁患儿中，轮状病毒性肠炎组SFB阳性率为9/15，对照组为50%（10/20），差异无统计学意义（P=0.734）。经Pearson相关性分析，随着SFB阳性率的增加，轮状病毒的感染率呈下降趋势（r=-0.87，P<0.001）。随着p3340特异蛋白浓度的增加，适合培养轮状病毒的Vero细胞荧光素酶的发光强度呈下降趋势（F=4.17，P=0.001）。 结论： 2岁以内婴幼儿肠道SFB定植与降低轮状病毒感染风险相关；克隆特定SFB功能蛋白p3340可以中和轮状病毒感染Vero细胞，且这种针对轮状病毒感染的机制可能不同于常见的抗病毒机制。.

Animal rotaviruses A (RVAs) are considered the source of emerging, novel RVA strains that have the potential to cause global spread in humans. A case in point was the emergence of G8 bovine RVA consisting of the P[8] VP4 gene and the DS-1-like backbone genes that appeared to have jumped into humans recently. However, it was not well documented what evolutionary changes occurred on the animal RVA-derived genes during circulation in humans. Rotavirus surveillance in Vietnam found that DS-1-like G8P[8] strains emerged in 2014, circulated in two prevalent waves, and disappeared in 2021. This surveillance provided us with a unique opportunity to investigate the whole process of evolutionary changes, which occurred in an animal RVA that had jumped the host species barrier. Of the 843 G8P[8] samples collected from children with acute diarrhoea in Vietnam between 2014 and 2021, fifty-eight strains were selected based on their distinctive electropherotypes of the genomic RNA identified using polyacrylamide gel electrophoresis. Whole-genome sequence analysis of those fifty-eight strains showed that the strains dominant during the first wave of prevalence (2014-17) carried animal RVA-derived VP1, NSP2, and NSP4 genes. However, the strains from the second wave of prevalence (2018-21) lost these genes, which were replaced with cognate human RVA-derived genes, thus creating strain with G8P[8] on a fully DS-1-like human RVA gene backbone. The G8 VP7 and P[8] VP4 genes underwent some point mutations but the phylogenetic lineages to which they belonged remained unchanged. We, therefore, propose a hypothesis regarding the tendency for the animal RVA-derived genes to be expelled from the backbone genes of the progeny strains after crossing the host species barrier. This study underlines the importance of long-term surveillance of circulating wild-type strains in order to better understand the adaptation process and the fate of newly emerging, animal-derived RVA among the human population. Further studies are warranted to disclose the molecular mechanisms by which spillover animal RVAs become readily transmissible among humans, and the roles played by the expulsion of animal-derived genes and herd immunity formed in the local population.

Postweaning diarrhea (PWD) is a multifactorial disease caused by different aetiological agents, like viruses or bacteria and where the role of the microbiota remains unclear. The aim of this study was to assess differences between healthy and diarrheic weaned pigs concerning the prevalence of pathogens and changes in the intestinal microbiota. Eighteen farms with PWD were selected and 277 fecal samples were collected (152 diarrheic vs 125 healthy). Presence of Rotavirus A (RVA), B (RVB), C (RVC) and Porcine Epidemic Diarrhea Virus (PEDV), virulence factors of Escherichia coli and Clostridioides difficile were analyzed by PCR. Finally, the microbiota composition was also study by 16 S rRNA sequencing on 148 samples (102 diarrheic vs 46 healthy). RVA (53.95 % vs 36 %, p=0.04) and RVB (49.67 % vs 28.8 %, p<0.001) were more frequent in diarrheic animals. Furthermore, RVA viral load was higher in diseased animals. VT2 toxin was significantly associated with diarrhea, whereas other virulence factors were not. Presence of C. difficile and PEDV was almost negligible. Regarding microbiota changes, Fusobacteriota phylum was more frequent in diarrheic samples and Ruminococcaceae family in healthy penmates. During the first week postweaning, Enterobacteriace and Campylobacteria were enriched in animals presenting diarrhea. Furthermore, Lactobacillus was detected in those individuals with no RVA infection. In conclusion, RVA seems to play a primary role in PWD. Classic E. coli virulence factors were not associated with diarrhea, indicating the need for revising their implication in disease. Moreover, Lactobacillus was found frequently in animals negative for RVA, suggesting some protective effect.

BACKGROUND: Gastroenteritis is a common cause of morbidity and mortality globally. Its cause encompasses a spectrum of agents, including viruses, bacteria, parasites, toxins, and drugs. Viruses account for a considerable portion of gastroenteritis cases across all age groups, typically presenting with symptoms like nausea, vomiting, diarrhea, dehydration, anorexia, and weight loss. While sporadic cases occur, viral gastroenteritis is more frequently observed in outbreaks within closely knit communities such as daycare facilities, nursing homes, and cruise ships. Therefore, it becomes necessary to determine when healthcare providers should consider this condition in their differential diagnosis and to develop the most effective strategy to confirm the diagnosis.
METHODS: De-identified data of patients with gastroenteritis were collected over a five-year period utilizing the Patient Cohort Explorer, an electronic health record at the University of Mississippi Medical Center. Confirmatory laboratory tests employed the BioFire® FilmArray® multiplex polymerase chain reaction for gastrointestinal pathogens. Out of the 22 most common agents associated with gastroenteritis, only viral pathogens, specifically adenovirus, astrovirus, norovirus, rotavirus, and sapovirus, were included in the analysis. When available, histopathology was reviewed.
RESULTS: Among the various causes of gastroenteritis, both infectious and non-infectious, our findings revealed that 25.46% of the cases were linked to viral pathogens. This included a significantly higher percentage of pediatric patients (72.73%) when compared to adults (27.07%), with a p-value of 0.015. Norovirus genogroups I and II emerged as the most frequently detected viruses across all age groups, with a significant prevalence among adults. No discernible gender-based differences were observed. The histopathological findings included inflammation, ulceration, erosion, architectural distortion, and the pathognomonic viral inclusion bodies associated with adenovirus.
CONCLUSIONS: Our comprehensive analysis of viral gastroenteritis cases highlights the substantial burden of this condition, particularly among pediatric patients. Norovirus emerges as a prevalent culprit which emphasizes the importance of vigilant surveillance and timely diagnosis, especially in settings where outbreaks are common.

Insect cells have long been the main expression host of many virus-like particles (VLP). VLPs resemble the respective viruses but are non-infectious. They are important in vaccine development and serve as safe model systems in virus research. Commonly, baculovirus expression vector system (BEVS) is used for VLP production. Here, we present an alternative, plasmid-based system for VLP expression, which offers distinct advantages: in contrast to BEVS, it avoids contamination by baculoviral particles and proteins, can maintain cell viability over the whole process, production of alphanodaviral particles will not be induced, and optimization of expression vectors and their ratios is simple. We compared the production of noro-, rota- and entero-VLP in the plasmid-based system to the standard process in BEVS. For noro- and entero-VLPs, similar yields could be achieved, whereas production of rota-VLP requires some further optimization. Nevertheless, in all cases, particles were formed, the expression process was simplified compared to BEVS and potential for the plasmid-based system was validated. This study demonstrates that plasmid-based transfection offers a viable option for production of noro-, rota- and entero-VLPs in insect cells.

Human rotaviruses exhibit limited tropism and replicate poorly in most cell lines. Attachment protein VP4 is a key rotavirus tropism determinant. Previous studies in which human rotaviruses were adapted to cultured cells identified mutations in VP4. However, most such studies were conducted using only a single human rotavirus genotype. In the current study, we serially passaged 50 human rotavirus clinical specimens representing five of the genotypes most frequently associated with severe human disease, each in triplicate, three to five times in primary monkey kidney cells then ten times in the MA104 monkey kidney cell line. From 13 of the 50 specimens, we obtained 25 rotavirus antigen-positive lineages representing all five genotypes, which tended to replicate more efficiently in MA104 cells at late versus early passage. We used Illumina next-generation sequencing and analysis to identify variants that arose during passage. In VP4, variants encoded 28 mutations that were conserved for all P[8] rotaviruses and 12 mutations that were conserved for all five genotypes. These findings suggest there may be a conserved mechanism of human rotavirus adaptation to MA104 cells. In the future, such a conserved adaptation mechanism could be exploited to study human rotavirus biology or efficiently manufacture vaccines.

Rotaviruses (RVs) are known to infect various avian and mammalian hosts, including swine. The most common RVs associated with infection in pigs are A, B, C and H (RVA-C; RVH). In this study we analysed rotavirus strains circulating on a porcine farm in the Western Cape province of South Africa over a two-year period. Whole genomes were determined by sequencing using Illumina MiSeq without prior genome amplification. Fifteen RVA genomes, one RVB genome and a partial RVC genome were identified. Phylogenetic analyses of the RVA data suggested circulation of one dominant strain (G5-P[6]/P[13]/P[23]-I5-R1-C1-M1-A8-N1-T7-E1-H1), typical of South African porcine strains, although not closely related to previously detected South African porcine strains. Reassortment with three VP4-encoding P genotypes was detected. The study also reports the first complete RVB genome (G14-P[5]-I13-R4-C4-M4-A10-T4-E4-H7) from Africa. The partial RVC (G6-P[5]-IX-R1-C1-MX-A9-N6-T6-EX-H7) strain also grouped with porcine strains. The study shows the continued circulation of an RVA strain, with a high reassortment rate of the VP4-encoding segment, on the porcine farm. Furthermore, incidents of RVB and RVC on this farm emphasize the complex epidemiology of rotavirus in pigs.

Diarrhea, often caused by viruses like rotavirus (RV) and norovirus (NV), is a global health concern. This study focuses on RV and NV in Jining City from 2021 to 2022. Between 2021 and 2022, a total of 1052 diarrhea samples were collected. Real-Time Quantitative Fluorescent Reverse Transcriptase-PCR was used to detect RV-A, NV GI, and NV GII. For RV-A-positive samples, VP7 and VP4 genes were sequenced for genotype analysis, followed by the construction of evolutionary trees. Likewise, for NV-GII-positive samples, VP1 and RdRp genes were sequenced for genotypic analysis, and evolutionary trees were subsequently constructed. Between 2021 and 2022, Jining City showed varying detection ratios: RV-A alone (excluding co-infection of RV-A and NV GII) at 7.03%, NV GI at 0.10%, NV GII alone (excluding co-infection of RV-A and NV GII) at 5.42%, and co-infection of RV-A and NV GII at 1.14%. The highest RV-A ratios were shown in children ≤1 year and 2-5 years. Jining, Jinxiang County, and Liangshan County had notably high RV-A ratios at 24.37% (excluding co-infection of RV-A and NV GII) and 18.33% (excluding co-infection of RV-A and NV GII), respectively. Jining, Qufu, and Weishan had no RV-A positives. Weishan showed the highest NV GII ratios at 35.48% (excluding co-infection of RV-A and NV GII). Genotype analysis showed that, in 2021, G9P[8] and G2P[4] were dominant at 94.44% and 5.56%, respectively. In 2022, G8P[8], G9P[8], and G1P[8] were prominent at 75.86%, 13.79%, and 10.35%, respectively. In 2021, GII.3[P12], GII.4[P16], and GII.4[P31] constituted 71.42%, 14.29%, and 14.29%, respectively. In 2022, GII.3[P12] and GII.4[P16] accounted for 55.00% and 45.00%, respectively. RV-A and NV showed varying patterns for different time frames, age groups, and regions within Jining. Genotypic shifts were also observed in prevalent RV-A and NV GII strains in Jining City from 2021 to 2022. Ongoing monitoring of RV-A and NV is recommended for effective prevention and control.

The replication of species A rotaviruses (RVAs) involves the recruitment of and interaction with cellular organelles\' lipid droplets (LDs), both physically and functionally. The inhibition of enzymes involved in the cellular fatty acid biosynthesis pathway or the inhibition of cellular lipases that degrade LDs was found to reduce the functions of \'viral factories\' (viroplasms for rotaviruses or replication compartments of other RNA viruses) and decrease the production of infectious progeny viruses. While many other RNA viruses utilize cellular lipids for their replication, their detailed analysis is far beyond this review; only a few annotations are made relating to hepatitis C virus (HCV), enteroviruses, SARS-CoV-2, and HIV-1.