Experimental bovine rotavirus-A (RV-A)infection causes intestinal and extra-intestinal pathology in suckling mice

Isolation and Genomic Characterization of the G6P[1]-Type Sheep Rotavirus in China

Rotavirus A (RVA) is a prevalent cause of enteric diarrhea in infants, bovine, pigs, and sheep globally. Currently, the G6P[1]-type rotaviruses are prevalent in sheep or goat in Bangladesh, Turkey, and Uganda. However, this genotype has not been reported in Chinese sheep or goat. Therefore, 12 anal swabs were collected from diarrheal sheep in Gansu Province, China, in 2023 and tested for rotavirus using reverse transcription-polymerase chain reaction (RT-PCR). Pathological sections and immunohistochemistry were used to observe pathological changes and rotavirus antigens in the duodenum, respectively. The sheep rotavirus was isolated in MA-104 cells and characterized through indirect immunofluorescence and transmission electron microscopy. The genes of the strain were obtained using the next-generation sequencing technology and analyzed phylogenetically. One sheep was positive for rotavirus by RT-PCR, and immunohistochemistry revealed numerous rotavirus antigens in the apical portion of the duodenal villi. Transmission electron microscopy revealed that the strain was characterized by virus particles that were "wheel-shaped" and measured 70-80 nm in size. The gene constellations of this strain is G6-P[1]-I2-R2-C2-M2-A11-N2-T6-E2-H3. BLASTn and phylogenetic tree analyses suggest that this strain is likely a recombinant of human rotavirus, goat rotavirus, and bovine rotavirus. The comparison of amino acid similarities revealed three differences in the key antigenic epitopes of the VP7 and VP4 proteins between the GO34 strain and this study strain despite the identical gene constellations of the two strains. To date, this is the first report of this constellation of RVA being found in sheep.

Rotavirus-related systemic diseases: clinical manifestation, evidence and pathogenesis

Rotaviruses, double-stranded, non-enveloped RNA viruses, are a global health concern, associated with acute gastroenteritis and secretory-driven watery diarrhoea, especially in infants and young children. Conventionally, rotavirus is primarily viewed as a pathogen for intestinal enterocytes. This notion is challenged, however, by data from patients and animal models documenting extra-intestinal clinical manifestations and viral replication following rotavirus infection. In addition to acute gastroenteritis, rotavirus infection has been linked to various neurological disorders, hepatitis and cholestasis, type 1 diabetes, respiratory illness, myocarditis, renal failure and thrombocytopenia. Concomitantly, molecular studies have provided insight into potential mechanisms by which rotavirus can enter and replicate in non-enterocyte cell types and evade host immune responses. Nevertheless, it is fair to say that the extra-intestinal aspect of the rotavirus infectious process is largely being overlooked by biomedical professionals, and there are gaps in the understanding of mechanisms of pathogenesis. Thus with the aim of increasing public and professional awareness we here provide a description of our current understanding of rotavirus-related extra-intestinal clinical manifestations and associated molecular pathogenesis. Further understanding of the processes involved should prove exceedingly useful for future diagnosis, treatment and prevention of rotavirus-associated disease.

Molecular characterization of rotaviruses obtained from patients with rotavirus-associated encephalitis/encephalopathy

Group A rotavirus (RVA) rarely causes severe complications such as encephalitis/encephalopathy. However, the pathophysiology of this specific complication remains unclear. Next-generation sequence analysis was used to compare the entire genome sequences of RVAs detected in patients with encephalitis/encephalopathy and gastroenteritis. This study enrolled eight patients with RVA encephalitis/encephalopathy and 10 with RVA gastroenteritis who were treated between February 2013 and July 2014. Viral RNAs were extracted from patients' stool, and whole-genome sequencing analysis was carried out to identify the specific gene mutations in RVA obtained from patients with severe neurological complications. Among the eight encephalitis/encephalopathy cases, six strains were DS-1-like G1P[8] and the remaining two were Wa-like G1P[8] (G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1). Meanwhile, eight of the 10 viruses detected in rotavirus gastroenteritis patients were DS-1-like G1P[8], and the remaining two were Wa-like G1P[8]. These strains were further characterized by conducting phylogenetic analysis. No specific clustering was demonstrated in RVAs detected from encephalitis/encephalopathy patients. Although the DS-1-like G1P[8] strain was predominant in both groups, no specific molecular characteristics were detected in RVAs from patients with severe central nervous system complications.

Immunohistochemical and molecular detection of natural cases of bovine rotavirus and coronavirus infection causing enteritis in dairy calves

Bovine rotavirus (BRoV) and bovine coronavirus (BCoV) are major enteric viral pathogens responsible for calve diarrhoea. They are widespread both in dairy and beef cattle throughout the world and causing huge economic losses. The diagnosis of these agents is very difficult due to non-specific nature of lesions and the involvement of some intrinsic and extrinsic risk factors. We performed postmortem of 45 calves, which was below three months of age. Out of 45 necropscid calves, three (6.66%) cases were positive for BRoV and four (8.88%) cases were found positive for BCoV, screened by reverse transcriptase polymerase chain reaction (RT-PCR). Further RT-PCR positive cases were confirmed by immunohistochemistry (IHC) in paraffin-embedded intestinal tissue sections. Three cases of enteritis caused by BRoV showed the hallmark lesions of the shortening and fusion of villi, denudation and infiltration of mononuclear cells in the lamina propria. The BRoV antigen distribution was prominent within the lining epithelium of the villi, peyer's patches in the ileum and strong immunoreactions in the lymphocytes and some macrophages of the mesenteric lymph nodes. Four cases in which BCoV was detected, grossly lesions characterized by colonic mucosa covered with thick, fibrinous and diphtheritic membrane. Histopathologically, jejunum showed skipping lesion of micro-abscesses in crypts. The BCoV antigen distribution was prominent within the necrotic crypts in the jejunum and cryptic micro-abscesses in the colon and ileum. It is the first report of BRoV and BCoV antigen demonstration in the jejunum, colon, ileum, Peyer's patches and mesenteric lymph nodes of naturally infected calves from India by using IHC.

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The present study was to investigation of natural cases of BRoV and BCoV infection causing enteritis in dairy calves.

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Out of 45 necropscid calves, 6.66% cases for BRoV and 8.88% cases for BCoV were found positive.

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BRoV and BCoV antigen demonstration in the jejunum, colon, ileum, Peyer's patches and mesenteric lymph nodes of infected calves by using IHC.