Whole genome characterisation of G11P[25] and G9P[19] rotavirus A strains from adult patients with diarrhoea in Nepal

Emergence of human-porcine reassortment G9P[19] porcine rotavirus A strain in Guangdong Province, China

Group A rotaviruses of the family Reoviridae is one of the important intestinal pathogens causing diarrhea in piglets and humans. A human-porcine reassortment rotavirus, GDJM1, was identified from outbreak of diarrhea in suckling piglets and it associated with 60.00% (324/540) morbidity and 20.99% (68/324) mortality in Guangdong Province of China in 2022. Thus, to further characterize the evolutionary diversity of GDJM1, all gene segments were analyzed. The genome constellation was G9-P[19]-I5-R1-C1-M1-A8-N1-T1-E1-H1. Nucleotide sequence identity and phylogenetic analyses showed that the VP6, VP7, NSP4 and NSP5 genes of GDJM1 were the most closely related to the respective genes of porcine strains, with the highest homology ranging from 95.65-98.55% identity. The remaining seven genes (VP1-VP4, NSP1-NSP3) were the most closely related to human strains, with the highest homology ranging from 91.83-96.69% similarity. Therefore, it is likely that GDJM1 emerged as the result of genetic reassortment between porcine and human rotaviruses. To our knowledge, this is the first report that a human-porcine reassortment G9P[19] RVA strain has been identified in mainland China, which providing important insights into evolutionary characterization of G9P[19] RVA strain, and reveals that the strain has a potential risk of cross-species transmission.

Australian Rotavirus Surveillance Program: Annual Report, 2018

Abstract

This report, from the Australian Rotavirus Surveillance Program and collaborating laboratories Australia-wide, describes the rotavirus genotypes identified in children and adults with acute gastroenteritis during the period 1 January to 31 December 2018. During this period, 690 faecal specimens were referred for rotavirus G- and P- genotype analysis, including 607 samples that were confirmed as rotavirus positive. Of these, 457/607 were wild-type rotavirus strains and 150/607 were identified as rotavirus vaccine-like. Genotype analysis of the 457 wild-type rotavirus samples from both children and adults demonstrated that G3P[8] was the dominant genotype nationally, identified in 52% of samples, followed by G2P[4] (17%). The Australian National Immunisation Program, which previously included both RotaTeq and Rotarix vaccines, changed to Rotarix exclusively on 1 July 2017. Continuous surveillance is needed to identify if the change in vaccination schedule could affect rotavirus genotype distribution and diversity in Australia.

Human group A rotavirus P[25] VP8* specifically binds to A-type histo-blood group antigen

Rotavirus (RV) is a common cause of acute gastroenteritis in young children. While P[8] and P[4] are the most prevalent RV genotypes in humans, other genotypes are also reported in human infections occasionally, including human P[25]. The glycan binding and structural characteristics of human P[25] were explored in our study. Human P[25] VP8* recognized type A histo-blood group antigen (HBGA) in the glycan microarray/oligosaccharide binding assay and could specifically hemagglutinate type A blood cells. Moreover, the P[25] VP8* structure was determined at 2.6 Å, revealing a similar conformation and a conserved putative glycan binding site as that of P[14] VP8*. This study provided further knowledge of the glycan binding and structural features of P[25] RV VP8*, promoting our understanding of the infection, prevalence, and host range of the P[III] RVs.

Prevalence and genome characterization of porcine rotavirus A in southern Mozambique

Rotavirus A (RVA) is an important pathogen causing gastroenteritis in many species, including humans and pigs. The objective of this study was to determine the prevalence of RVA in pigs from smallholdings and commercial farms in southern Mozambique and characterize the complete genomes of selected strains. RVA was detected at a rate of 11.8% (n = 288), of which 7.6% was detected at commercial farms and 4.2% at smallholdings. The whole genomes of eight rotavirus strains were determined using an Illumina MiSeq platform. Seven displayed a G9P[13] and one a G4P[6] genotype combination, all with a typical porcine backbone (I1/5-R1-C1-M1-A1/8-N1-T1/7-E1-H1). Phylogenetic analysis indicated that the seven G9P[13] strains were in fact one strain that circulated on a commercial pig farm. The genome segments of this strain clustered with diverse segments of human and porcine RVA strains from various Asian countries. Analysis of the G4P[6] strain revealed four distinct genome segments (VP2, VP4, VP6 and VP7) and five genome segments closely related to South African porcine rotavirus strains (NSP1, NSP3, NSP4, NSP5 and VP1). These results suggest that both the G4P[6] and the G9P[13] strains possibly emerged through multiple reassortment events. The presence of these strains on the commercial farms and smallholdings calls for a more in-depth surveillance of rotavirus in Mozambique.