Detection and characterisation of group A rotavirus in asymptomatic piglets in southern Ireland

Abstract

Porcine group A rotaviruses (GARV) are causative agents of enteritis in piglets and are a large reservoir of genetic material for the diversification of human GARVs. Accumulation of information on the genetic heterogeneity of porcine viruses is pivotal for readily characterising unusual human strains. Screening of 292 fecal samples, collected from 4-5- to 8-9-week-old asymptomatic pigs from four herds in Ireland between 2005 and 2007 resulted in 19 (6.5%) samples testing positive by reverse-transcription PCR (RT-PCR) for GARV. The strains were molecularly characterized to collate data on the VP7 and partial VP4 outer capsid genes. By sequence analysis of the VP7 gene, the Irish strains were identified as G2, G4, G5, G9 and G11 viruses. The G11 strains were closely related to other human and porcine G11 strains, while the G2 strains resembled porcine G2 viruses detected recently in Europe and southern Asia. The G4 strains were distantly related to other G4 human and animal strains, constituting a separate G4 VP7 lineage. Analysis of the G5 strains revealed that they were similar to a selection of G5 human and porcine strains, while the G9 strains resembled other porcine G9 viruses. By sequence analysis of the VP8* fragment of the VP4, the Irish viruses were characterised as P[6], P[7], P[13], P[13]/[22], P[26] and P[32].

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

“…Phylogenic analysis enabled us to classify the 65 RVA VP4 sequences as one of six P genotypes (P [6], P [7], P [13], P [23], P [27], and P [34]) of 35 established P genotypes (Fig. 2).…”

“…P [7] genotypes were detected most frequently (39.4%, n ϭ 28), followed by P [13] (22.5%, n ϭ 16), P[27] (14.1%, n ϭ 10), P[6] (7.0%, n ϭ 5), P [34] (5.6%, n ϭ 4), and P[23] (2.8%, n ϭ 2). The nucleotide sequences corresponding to the P [6], P [7], P [23], P [27], and P [34] genotypes shared greater than 99.0% nt identities, and each genotype was able to be assigned to a single branch (Fig. 2).…”

“…Although five G genotypes (G1 to G4, and G9) and three P genotypes (P [4], P [6], and P [8]) represent the majority of clinically important RVA strains in humans (36), the intensive RVA surveillance associated with introduction of the RVA vaccine into human populations has resulted in the detection of RVAs with unusual genotypes, including those commonly detected in pigs and cattle (14,19,21,29,38). Animal RVAs are therefore regarded as a potential reservoir for the genetic diversity of human RVAs, and consequently their ecology has been of great concern (24).…”

“…Understanding the viral ecology within a pig population is crucial for preventing or reducing the incidence of porcine RVA diarrhea as well as transmission of porcine RVAs to humans. However, most studies of porcine RVAs have focused on the genotypes present in suckling and weaned pigs (6,16,41), which is not informative about viral ecology and genotypic characteristics when animals are raised on farms over an extended period.…”

Genotype diversity of group A rotavirus strains in children with acute diarrhea in urban Burkina Faso, 2008–2010

“…The nature of two outer capsid proteins of the virus, VP4 and VP7, elicits the production of neutralizing antibodies to the virus [Hoshino et al, 1985;Offit et al, 1986] and allows to define the P (for P sensitive) and G (for glycoprotein) serotypes of the virus. Currently, 23 G genotypes and 32 P genotypes have been described, based on nucleotide sequence variation [Matthijnssens et al, 2008a[Matthijnssens et al, ,b, 2009Ursu et al, 2009;Collins et al, 2010]. Global epidemiologic surveys have identi- and G9P[8] as the most common global G/P genotype combinations associated with diarrhea in humans Estes and Kapikian, 2007].…”