Hajnalka Papp

Review of group A rotavirus strains reported in swine and cattle

Abstract Group A rotavirus (RVA) infections cause severe economic losses in intensively reared livestock animals, particularly in herds of swine and cattle. RVA strains are antigenically heterogeneous, and are classified in multiple G and P types defined by the two outer capsid proteins, VP7 and VP4, respectively. This study summarizes published literature on the genetic and antigenic diversity of porcine and bovine RVA strains published over the last 3 decades. The single most prevalent genotype combination among porcine RVA strains was G5P[7], whereas the predominant genotype combination among bovine RVA strains was G6P[5], although spatiotemporal differences in RVA strain distribution were observed. These data provide important baseline data on epidemiologically important RVA strains in swine and cattle and may guide the development of more effective vaccines for veterinary use.

Whole genome sequencing and phylogenetic analysis of a zoonotic human G8P[14] rotavirus strain.

The full-length genome of a rare human G8P[14] rotavirus strain, BP1062/04, identified during a surveillance study in Hungary was determined and analyzed. This strain showed a G8-P[14]-I2-R2-C2-M2-A11-N2-T6-E2-H3 genomic constellation. Phylogenetic analysis of each genome segment revealed common origins with selected animal and zoonotic human strains. The closest relatedness was seen with suspect zoonotic Hungarian G6P[14] strains in the NSP1 and NSP3 gene phylogeny, with ovine strains in the VP1, VP2, NSP4 gene phylogeny, and with bovine strains in the NSP5 gene phylogeny. The outer capsid VP7 and VP4 genes could not be derived from cognate genes of any known human or animal G8P[14] strains. The remaining genes, NSP2, VP3 and VP6, gave no definite clues to the host origin, although each was clearly different from true human strains. Altogether, our findings suggest that strain BP1062/04 represents an example of a direct zoonotic transmission event.

Complete molecular genome analyses of equine rotavirus A strains from different continents reveal several novel genotypes and a largely conserved genotype constellation

In this study, the complete genome sequences of seven equine group A rotavirus (RVA) strains (RVA/Horse-tc/GBR/L338/1991/G13P[18], RVA/Horse-wt/IRL/03V04954/2003/G3P[12] and RVA/Horse-wt/IRL/04V2024/2004/G14P[12] from Europe; RVA/Horse-wt/ARG/E30/1993/G3P[12], RVA/Horse-wt/ARG/E403/2006/G14P[12] and RVA/Horse-wt/ARG/E4040/2008/G14P[12] from Argentina; and RVA/Horse-wt/ZAF/EqRV-SA1/2006/G14P[12] from South Africa) were determined. Multiple novel genotypes were identified and genotype numbers were assigned by the Rotavirus Classification Working Group: R9 (VP1), C9 (VP2), N9 (NSP2), T12 (NSP3), E14 (NSP4), and H7 and H11 (NSP5). The genotype constellation of L338 was unique: G13-P[18]-I6-R9-C9-M6-A6-N9-T12-E14-H11. The six remaining equine RVA strains showed a largely conserved genotype constellation: G3/G14-P[12]-I2/I6-R2-C2-M3-A10-N2-T3-E2/E12-H7, which is highly divergent from other known non-equine RVA genotype constellations. Phylogenetic analyses revealed that the sequences of these equine RVA strains are related distantly to non-equine RVA strains, and that at least three lineages exist within equine RVA strains. A small number of reassortment events were observed. Interestingly, the three RVA strains from Argentina possessed the E12 genotype, whereas the three RVA strains from Ireland and South Africa possessed the E2 genotype. The unusual E12 genotype has until now only been described in Argentina among RVA strains collected from guanaco, cattle and horses, suggesting geographical isolation of this NSP4 genotype. This conserved genetic configuration of equine RVA strains could be useful for future vaccine development or improvement of currently used equine RVA vaccines.

Zoonotic transmission of reassortant porcine G4P[6] rotaviruses in Hungarian pediatric patients identified sporadically over a 15 year period.

Genotype G4P[6] Rotavirus A (RVA) strains collected from children admitted to hospital with gastroenteritis over a 15 year period in the pre rotavirus vaccine era in Hungary were characterized in this study. Whole genome sequencing and phylogenetic analysis was performed on eight G4P[6] RVA strains. All these RVA strains shared a fairly conservative genomic configuration (G4-P[6]-I1/I5-R1-C1-M1-A1/A8-N1-T1/T7-E1-H1) and showed striking similarities to porcine and porcine-derived human RVA strains collected worldwide, although genetic relatedness to some common human RVA strains was also seen. The resolution of phylogenetic relationship between porcine and human RVA genes was occasionally low, making the evaluation of host species origin of individual genes sometimes difficult. Yet the whole genome constellations and overall phylogenetic analyses indicated that these eight Hungarian G4P[6] RVA strains may have originated by independent zoonotic transmission, probably from pigs. Future surveillance studies of human and animal RVA should go parallel to enable the distinction between direct interspecies transmission events and those that are coupled with reassortment of cognate genes.

One Year Survey of Human Rotavirus Strains Suggests the Emergence of Genotype G12 in Cameroon

In this study the emergence of rotavirus A genotype G12 in children <5 years of age is reported from Cameroon during 2010/2011. A total of 135 human stool samples were P and G genotyped by reverse transcriptase PCR. Six different rotavirus VP7 genotypes were detected, including G1, G2, G3, G8, G9, and G12 in combinations with P[4], P[6] and P[8] VP4 genotypes. Genotype G12 predominated in combination with P[8] (54.1%) and P[6] (10.4%) genotypes followed by G1P[6] (8.2%), G3P[6] (6.7%), G2P[4] (5.9%), G8P[6] (3.7%), G2P[6] (0.7%), G3P[8] (0.7%), and G9P[8] (0.7%). Genotype P[6] strains in combination with various G‐types represented a substantial proportion (N = 44, 32.6%) of the genotyped strains. Partially typed strains included G12P[NT] (2.2%); G3P[NT] (0.7%); G(NT)P[6] (1.5%); and G(NT)P[8] (0.7%). Mixed infections were found in five specimens (3.7%) in several combinations including G1 + G12P[6], G2 + G3P[6] + P[8], G3 + G8P[6], G3 + G12P[6] + P[8], and G12P[6] + P[8]. The approximately 10% relative frequency of G12P[6] strains detected in this study suggests that this strain is emerging in Cameroon and should be monitored carefully as rotavirus vaccine is implemented in this country, as it shares neither G‐ nor P‐type specificity with strains in the RotaTeq® and Rotarix® vaccines. These findings are consistent with other recent reports of the global spread and increasing epidemiologic importance of G12 and P[6] strains. J. Med. Virol. 85:1485–1490, 2013.

Novel NSP4 genotype in a camel G10P[15] rotavirus strain

In this study a Kuwaiti camel rotavirus strain, RVA/Camel-wt/KUW/s21/2010/G10P[15], is characterized by sequencing and phylogenetic analysis. The strain had multiple genes with high nucleotide sequence similarities to ovine and bovine strains (VP2, ≤ 96%; NSP2 and NSP5, ≤ 97%, NSP3, ≤ 94%), or, to porcine strains (VP1, ≤ 89%). Other genes had moderate sequence similarities (VP4, ≤ 87%; VP6, ≤ 81%; VP7, ≤ 82%) with reference strains from ruminants. The NSP4 gene shared limited sequence identity (≤ 71%) with other mammalian and avian rotavirus NSP4 types, and was designated a novel genotype, E15. This study demonstrates genetic diversity in the outer capsid and some backbone genes of an old-world camelid rotavirus strain and uncovers its common evolutionary roots with strains from other ruminants.

Global distribution of group A rotavirus strains in horses: A systematic review

Group A rotavirus (RVA) is a major cause of diarrhea and diarrhea-related mortality in foals in parts of the world. In addition to careful horse farm management, vaccination is the only known alternative to reduce the RVA associated disease burden on horse farms. The precise evaluation of vaccine effectiveness against circulating strains needs enhanced surveillance of equine RVAs in areas where vaccine is already available or vaccine introduction is anticipated. Therefore, we undertook the overview of relevant information on epidemiology of equine RVA strains through systematic search of public literature databases. Our findings indicated that over 99% of equine RVA strains characterized during the past three decades belonged to two common genotypes, G3P[12] and G14P[12], whereas most of the minority equine RVA strains were probably introduced from a heterologous host by interspecies transmission. These baseline data on RVA strains in horses shall contribute to a better understanding of the spatiotemporal dynamics of strain prevalence in vaccinated and non-vaccinated herds.

Detection of rare reassortant G5P[6] rotavirus, Bulgaria

During the ongoing rotavirus strain surveillance program conducted in Bulgaria, an unusual human rotavirus A (RVA) strain, RVA/Human/BG/BG620/2008/G5P[6], was identified among 2200 genotyped Bulgarian RVAs. This strain showed the following genomic configuration: G5-P[6]-I1-R1-C1-M1-A8-N1-T1-E1-H1. Phylogenetic analysis of the genes encoding the neutralization proteins and backbone genes identified a probable mixture of RVA genes of human and porcine origin. The VP1, VP6 and NSP2 genes were more closely related to typical human rotavirus strains. The remaining eight genes were either closely related to typical porcine and unusual human-porcine reassortant rotavirus strains or were equally distant from reference human and porcine strains. This study is the first to report an unusual rotavirus isolate with G5P[6] genotype in Europe which has most likely emerged from zoonotic transmission. The absence of porcine rotavirus sequence data from this area did not permit to assess if the suspected ancestral zoonotic porcine strain already had human rotavirus genes in its genome when transmitted from pig to human, or, the transmission was coupled or followed by gene reassortment event(s). Because our strain shared no neutralization antigens with rotavirus vaccines used for routine immunization in children, attention is needed to monitor if this G-P combination will be able to emerge in human populations. A better understanding of the ecology of rotavirus zoonoses requires simultaneous monitoring of rotavirus strains in humans and animals.

Surveillance of human rotaviruses in 2007–2011, Hungary: Exploring the genetic relatedness between vaccine and field strains

BACKGROUND The availability of rotavirus vaccines has resulted in an intensification of post vaccine strain surveillance efforts worldwide to gain information on the impact of vaccines on prevalence of circulating rotavirus strains. OBJECTIVES In this study, the distribution of human rotavirus G and P types in Hungary is reported. In addition, the VP4 and VP7 genes of G1P[8] strains were sequenced to monitor if vaccine-derived strains were introduced and/or some strains/lineages were selected against. STUDY DESIGN The study was conducted in 8 geographic areas of Hungary between 2007 and 2011. Rotavirus positive stool samples were collected from diarrheic patients mostly <5 years of age. Viral RNA was amplified by multiplex genotyping RT-PCR assay, targeting the medically most important G and P types. When needed, sequencing of the VP7 and VP4 genes was performed. RESULTS In total, 2380 strains were genotyped. During the 5-year surveillance we observed the dominating prevalence of genotype G1P[8] (44.87%) strains, followed by G4P[8] (23.4%), G2P[4] (14.75%) and G9P[8] (6.81%) genotypes. Uncommon strains were identified in a low percentage of samples (4.12%). Phylogenetic analysis of 318 G1P[8] strains identified 55 strains similar to the Rotarix strain (nt sequence identities; VP7, up to 97.9%; VP4, up to 98.5%) although their vaccine origin was unlikely. CONCLUSIONS Current vaccines would have protected against the majority of identified rotavirus genotypes. A better understanding of the potential long-term effect of vaccine use on epidemiology and evolutionary dynamics of co-circulating wild type strains requires continuous strain surveillance.

Monitoring of group A rotaviruses in wild-living birds in Hungary.

SUMMARY. Rotavirus is a common pathogen causing gastroenteritis in humans and domesticated animals. The incidence of rotavirus in wild-living animals, particularly in avian species, has not been systematically investigated. In this study 1220 fecal samples and cloacal swabs collected from wild-living birds during 2008 in Hungary were tested for the presence of group A rotaviruses by a VP6 gene-specific reverse-transcription–polymerase-chain-reaction assay. Of the 1220 samples, 276 and 944 were processed as individual and pooled specimens, respectively. Rotavirus was identified in two pooled pheasant (Phasianus colchicus) samples and two individual reed bunting samples (Emberiza schoeniclus). These data indicated a very low prevalence of group A rotaviruses (0.3%) in our sample set. Nonetheless, the present study, together with existing literature data, implies that rotavirus infections occur in a wide spectrum of feral bird species. These findings are exciting and suggest that pursuing rotavirus monitoring is needed to uncover avian rotavirus strain diversity and understand rotavirus ecology in nature.