Full genome characterization of a human‐porcine reassortment G12P[7] rotavirus and its pathogenicity in piglets

Abstract

In recent years, increasing numbers of cases of acute gastroenteritis caused by Group A rotavirus (RVA) G12 strains have been reported in humans from many countries around the world, but G12 RVA detection in animals is currently less reported. Pigs are an important animal reservoir of zoonotic RVs and a mixing vessel for RVs. In 2020, RVA infection cases in piglets increased in China, which attracted more attention. During an epidemiological survey, a new type of porcine G12P[7] strain (CN127) was detected in pig farms across several provinces. Complete genome analyses revealed that strain CN127 possessed a Wa‐like backbone with a genotype constellation of G12‐P[7]‐I1‐C1‐M1‐R1‐A8‐N1‐T1‐E1‐H1. The A8 genotype is indicative of its porcine rotavirus origin. Sequence identities and phylogenetic analyses showed that the VP2, VP4, NSP1, NSP4 and NSP5 genes were most closely related to those of porcine rotaviruses, but the VP1, VP6, VP7 and NSP2‐3 genes were most closely related to those of human rotaviruses. CN127 likely emerged due to genetic reassortment between porcine and human rotavirus. In vivo experiments showed that CN127 infection caused gastrointestinal tract lesions in piglets and histopathological changes in the lung, liver and mesenteric lymph nodes (MLNs). In the small intestine, RVA antigen was detected in the duodenum and jejunum but not in the ileum. In the extra‐intestinal tissues, RVA antigen was detected in the lung but not in the MLNs. Viral RNA was detected in the intestinal and extra‐intestinal tissues as well as blood. This study reveals that RVA G12P[7] may become an epidemic strain in China and also provides further evidence that cocirculating human and porcine strains could produce new genotype rotaviruses with high virulence in piglets.

Isolation and Pathogenicity Analysis of a G5P[23] Porcine Rotavirus Strain

“…In a previous study, diarrhea was reported in piglets infected with PRG942 (G9P [23]) and PRG9121 (G9P [7]) strains at 1-8 dpi [42]. Furthermore, Miao et al reported diarrhea in 1-day-old piglets infected with the CN127 strain after 6-24 h, which continued until euthanization at 48 h, but none of them died due to the infection [38].…”

Commentary: Identification of pulmonary infections with porcine Rotavirus A in pigs with respiratory disease

“…More and more evidence shows that RVA belonging to G9 and G12 genotypes was detected in the lungs and nasal swabs associated with lung damage ( 10 ). To some extent, these studies indicated that (1) the respiratory transmission route was another route of RV transmission, (2) the lungs could be another target for RV infection, and (3) nasal swabs or lung samples should be considered candidate samples for the detection of RV.…”

Isolation and Pathogenicity Analysis of a G5P[23] Porcine Rotavirus Strain

“…PoRVs are prevalent worldwide and result in significant economic losses to the swine industry [ 15 ]. Isolation and cell-based cultivation of PoRV can help understand their pathogenicity in piglets [ 38 ]. In this study, PoRV-positive samples from a pig farm, suffering from diarrhea in suckling piglets, were treated with 10 µg/mL trypsin for 1 h, and the optimal conditions for the isolation of PoRV were established by adding trypsin to a final concentration of 4 µg/mL in the maintenance medium.…”

“…In a previous study, diarrhea was reported in piglets infected with PRG942 (G9P[23]) and PRG9121 (G9P[7]) strains at 1–8 dpi [ 42 ]. Furthermore, Miao et al reported diarrhea in 1-day-old piglets infected with the CN127 strain after 6–24 h, which continued until euthanization at 48 h, but none of them died due to the infection [ 38 ].…”