Analysis of the Excretion Dynamics and Genotypic Characteristics of Rotavirus A during the Lives of Pigs Raised on Farms for Meat Production

Abstract

To determine the excretion dynamics and genotypic characteristics of rotavirus A (RVA), a longitudinal observational study was performed in 10 pigs from 3 litters at a farrow-to-finish farm. A total of 400 fecal samples were directly collected from the rectums of individual pigs (aged 7 to 217 days) at 3- to 14-day intervals. Seventy-one samples (17.5%) were positive for RVA by reverse transcription-PCR designed to detect the VP7 and VP4 genes. At least 13 combinations of 5 G (G2, G4, G5, G9, and G11) and 6 P (P[6], P[7], P[13], P[23], P[27], and P[34]) genotypes were identified by direct sequencing of the PCR products. We were able to detect RVA VP7 sequences from each pig 4 to 6 times with intervals of 7 to 52 days (from 7 to 119 days of age). Each pig harbored RVAs with at least 3 to 6 different combinations of G and P genotypes, while repeated excretions of RVAs carrying the same combinations of G and P genotypes were also observed. Virus shedding and changes in G and P genotypes appeared to be associated with movement of the pigs into weaning, growing, and finishing barns. These results indicated that, over their lifetimes, pigs raised for meat frequently and intermittently excrete genetically diverse RVAs.

Diversity of group A rotavirus on a UK pig farm

“…Four rotavirus VP7 genotypes (G2, G3, G4 and G5) and three VP4 genotypes (P[6], P[7] and P[32]) were detected on the study farm and almost every combination of these genotypes was found over the 2 years. This extent of genetic heterogeneity is similar to that described in similar studies of GARV on pig farms in other countries ( Amimo et al, 2013 , Lachapelle et al, 2014 , Miyazaki et al, 2013 , Miyazaki et al, 2012 ).…”

Phylogenetic Analyses of the VP4 and VP7 Genes of Porcine Group A Rotaviruses in São Paulo State, Brazil: First Identification of G5P[23] in Piglets

“…These results are in accordance with the findings of a previous study (10). Furthermore, asymptomatic rotavirus infections in pigs have caused concern, as rotaviruses are excreted from subclinically infected animals and can cause diarrheal outbreaks in herds (11,12). The novel primers used (Table 1) were advantageous for the molecular characterization of the rotaviruses in the samples.…”

“…The P [23] genotype has been described as predominant in Thailand (16,32) and was isolated from a pig in China (33). Pigs are regarded as important reservoirs for human rotavirus diversification (10,12,28,34). A study comparing rotavirus genotypes and the pathogenicity and virulence caused by amino acid indels is required for a broader understanding of the infections caused by rotaviruses.…”

Complete Genome Characterization of Recent and Ancient Belgian Pig Group A Rotaviruses and Assessment of Their Evolutionary Relationship with Human Rotaviruses

“…Another explanation for the higher genetic diversity in the pig genes might be the existence of a stronger evolutionary drift in pig RVAs than in human RVAs. This is not unlogical, as pigs repeatedly come into contact with different rotavirus strains during the intense production stages (35,36).…”