Detection and molecular characterization of porcine group C rotaviruses in South Korea

Abstract

Group C rotaviruses (GCRVs) cause acute diarrhea in humans and animals worldwide and the evidence for a possible zoonotic role of GCRVs has been recently provided. However, there is little evidence of porcine GCRV infections or of their genetic diversity in South Korea. We examined 137 diarrheic fecal specimens from 55 farms collected from six provinces. RT-PCR utilizing primer pairs specific for the GCRV VP6 gene detected GCRV-positive reactions in 36 (26.2%) diarrheic fecal samples. Of these, 17 samples (12.4%) tested positive for porcine GCRVs alone and 19 samples (13.8%) were also positive for other pathogens. Other enteric pathogens except for GCRV were detected in 64 feces samples (46.7%) and no enteric pathogens were evident in 37 feces samples (27.0%). Phylogenetic and sequence homology analyses of GCRV partial VP6 gene between 23 Korean and other known porcine GCRVs demonstrated that Korean strains belonged to the porcine lineage. Furthermore, one Korean porcine strain shared the highest nucleotide (89.7-89.0%) and deduced amino acid sequence (92.9-93.9%) identities with bovine GCRV strains and was placed in the bovine GCRV lineage indicative of bovine origin. In conclusion, porcine GCRV infections are widespread in piglets with diarrhea in South Korea. The infecting porcine GCRVs mostly belong to the porcine lineage with the exception of one bovine-like GCRV, which possibly originated from bovine GCRV due to interspecies transmission.

Development of One-Step Real-Time Reverse Transcription Polymerase Chain Reaction Assays for Rapid Detection of Porcine Group C Rotaviruses

“…The authors previously reported that the prevalence of porcine GCRV infections in South Korea is 26% of the surveyed diarrheic fecal samples by conventional RT-PCR. 10 However, the present findings by both real-time RT-PCR assays indicate that the fecal prevalence of the porcine GCRVs in piglet diarrhea is much higher than that reported previously in South Korea. 10 Although RT-PCR has been used for the detection of porcine GCRV, 4,10 this assay cannot measure the viral load in the stool samples, resulting in a significant gap in veterinary knowledge about virological and epidemiological features.…”

“…10 However, the present findings by both real-time RT-PCR assays indicate that the fecal prevalence of the porcine GCRVs in piglet diarrhea is much higher than that reported previously in South Korea. 10 Although RT-PCR has been used for the detection of porcine GCRV, 4,10 this assay cannot measure the viral load in the stool samples, resulting in a significant gap in veterinary knowledge about virological and epidemiological features. Therefore, the copy number of porcine GCRV in the stool samples by real-time RT-PCR assays was evaluated.…”

“…10 For the detection of porcine GCRV, 0.1 g of feces was suspended in 0.9 ml phosphate buffered saline, yielding a 10% suspension. 10 The mixture was vortexed for 1 min and centrifuged at 2,060 3 g for 10 min at 4uC. The viral RNA was purified from 200 ml of fecal mixture using a viral RNA mini kit a according to the manufacturer's instructions.…”

“…10 The SYBR Green and TaqMan real-time RT-PCR assays were performed with primers and probe (Table 1), which were designed from the published sequence of the highly conserved region of porcine GCRV VP6 gene. b Both realtime RT-PCR assays were carried out using a commercial real-time amplification system c and a commercial 1-step RT-PCR kit.…”

Unexpected detection of porcine rotavirus C strains carrying human origin VP6 gene

“…Relevance of RVC is being augmented because piggery constitutes the main livelihood framework of rural and tribal population in many developing countries along with the possibility of zoonotic potential as indicated in earlier studies (Iturriza-Gomara et al 2004;Gabbay et al 2008). Detection of porcine-type RV in bovine sample and bovine-type isolate in porcine sample (Jeong et al 2009) also support the possibility of species jumping or re-assortment events. In India, only human RVCs are identified till to date (Brown et al 1988) and this group of RV could not mark its presence in other species before.…”