Molecular characterization of equine rotaviruses isolated in Europe in 2013: Implications for vaccination

Abstract

Equine group A rotavirus (RVAs) mainly cause disease in foals under the age of 3 months. Only sporadic data are available on the circulation of RVAs in equine populations in Europe. In this study, 65 diarrheic samples from foals under 4 months of age were collected in Belgium (n=32), Germany (n=17), Slovenia (n=5), Sweden (n=4), Hungary (n=3), Italy (n=2), France (n=1) and The Netherlands (n=1). Forty percent of these samples (n=26) were found to be RVA positive by a quantitative RT-PCR assay. The viral load in 11 of these samples was sufficiently high to be (partially) genotyped. G3, G14 and P[12] were the main genotypes detected, and phylogenetic analyses revealed that they were closely related to contemporary equine RVA strains detected in Europe as well as in Brazil and South Africa. Regional variation was observed with only G14 and P[12] being detected in Germany, whereas mainly G3P[12] was encountered in Belgium. Surprisingly the only G14P[12] RVA strain detected in Belgium was also found to possess the very rare P[18] genotype, which has been described only once from equine RVA strain L338 detected in the UK in 1991. Despite the identification of this uncommon P[18] genotype, G3P[12] and G14P[12] RVA strains remained the most important genotypes in Europe during the study period. Based on this finding and the knowledge that G3P[12] and G14P[12] serotypes are partially cross-reactive it can be assumed that a vaccine based on an inactivated virus of the G3P[12] genotype is still relevant in the current European epidemiological situation, although the addition of a G14 strain would most likely be beneficial.

Comparison of electron microscopy, ELISA, real time RT-PCR and insulated isothermal RT-PCR for the detection of Rotavirus group A (RVA) in feces of different animal species

“…The Ct values obtained by the in-house rtRT-PCR assay were 21 and 18.3, compared to 26.18 and 36.01, respectively, by the commercial rtRT-PCR kit. While we did not have additional equine samples to further examine this, these high Ct values from equine samples are consistent with a previous report (Matthijnssens et al, 2015) in which the same commercial molecular assay was also used for diarrheic samples from equine. Ct values for positive samples from that study ranged from 26.18-36.01.…”

Development and evaluation of a one-step multiplex real-time TaqMan® RT-qPCR assay for the detection and genotyping of equine G3 and G14 rotaviruses in fecal samples

“…Group A rotaviruses are a primary cause of diarrhea in children and animal species, including horses [1-6, 43, 44]. Even though seven G-types and six P-types of ERVA have been identified in horses, the G3P [12] and G14P [12] constitute the most epidemiologically relevant genotypes [1,2,[17][18][19]. Spatial as well as temporal fluctuations between these predominant G-types (G3 and G14) of ERVA circulating in equine populations have been reported around the world [2,30].…”

“…Currently, 27 G-types and 35 P-types of RVA have been recognized in several species including humans [9]. Thus far, seven G-types (G3, G5, G6, G8, G10, G13 and G14) and six P-types (P [1], P [3], P [7], P [11], P [12] and P [18]) have been identified among the RVA affecting horses, with G3P [12] and G14P [12] being the most prevalent and epidemiologically relevant genotypes [1,2,[17][18][19]. Other genomic arrangements involving G-and P-types different from G3/G14 and P [12] have been infrequently described as infecting horses [1].…”

Genetic linkage of capsid protein-encoding RNA segments in group A equine rotaviruses

“…Based on differences within RVA, a number of genotypes have been described for the VP4 (P[1]-P[37]), VP6 (I1-I16) and VP7 (G1-G27) gene (Estes & Greenberg, 2013;Matthijnssens et al, 2012;Trojnar et al, 2013 (Browning et al, 1991;Ciarlet et al, 2001;Isa et al, 1996;Miño et al, 2013;Taniguchi et al, 1994), G3P[12] and G14P[12] are the most prevalent strains associated with diarrhoea in foals worldwide. Rotavirus strains carrying the G3 genotype have been found in a wide range of host species (Estes & Greenberg, 2013;Martella et al, 2010), but the equine-like G3, G14 and P[12] genotypes have never been found producing outbreaks in any other host species than equines (Bailey et al, 2013;Garaicoechea et al, 2011;Matthijnssens et al, 2015;Weinberg et al, 2013). Genomes of equine RVA G3P [12] and G14P[12] are highly conserved, and only three gene segments have shown different genotypes (i.e.…”