Sessions

Rotaviruses belonging to the family Sedoreoviridae are important causative agents of acute gastroenteritis in both humans and animals. Within the genus Rotavirus, nine distinct species can be distinguished, designated by the letters A–J. The viral genome consists of 11 double-stranded RNA segments encoding six structural (VP) and five or six non-structural (NSP) proteins. Strains are classified into G and P genotypes based on the VP4 and VP7 genes. The presence of rotavirus H (RVH) has been demonstrated in pig populations in several countries, however, its clinical significance remains unclear. The aim of our study was to assess the occurrence of RVH in samples collected from pig herds in Hungary and to investigate the genetic diversity of the detected strains.

A total of 77 fecal swab samples were examined, originating from 16 pig herds affected by diarrhoeal disease. The samples were analysed using Nanopore next-generation sequencing, while sequence data processing and analysis were performed using Geneious Prime. Genetic characterization was based on the VP7 and VP4 genes. Phylogenetic trees were constructed using the maximum likelihood method in MEGA X, with 1000 bootstrap replicates.

RVH was detected in 21% of the examined samples and in 38% of the herds included in the study. Our results confirmed the presence of the virus in geographically distinct pig herds in Hungary. The VP7 and VP4 gene sequences of three RVH strains were determined, revealing the genotype combinations G18P[12], G4P[12], and G18P[10]. Phylogenetic analyses showed that the closest relatives of the Hungarian strains were previously described European RVH strains, predominantly those originating from Italy. However, the Hungarian sequences also formed distinct clusters within the known genotypes.

To our knowledge, this study provides the first genetic data on RVH strains circulating in Hungarian pig herds. Further research is required to clarify the clinical significance of RVH. Future whole-genome analyses may facilitate more detailed characterization of these strains and enable the investigation of potential reassortment and recombination events.