• Pediatric Infection and Vaccine
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• v.11 no.1
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• pp.59-72
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• 2004

Purpose : Rotaviruses are the major cause of gastroenteritis in infants and young children worldwide. It is important to get the epidemiologic data of rotavirus genotype for the application of rotavirus vaccine. So we tried to investigate the distribution of rotavirus genotypes with RT-PCR. Methods : A total of 120 rotavirus latex agglutinin test positive stool samples were collected continually from 120 children from Sep. 2000 to Apr. 2001. Rotavirus P(VP4), G (VP7) genotypes were determined by RT-PCR. Results : The genotype was identified in 116 stool samples of total 120 samples(96%). The incidence of G genotype was as follow; G1 17(14.2%), G2 74(61.7%), G4 1(0.8%), G9 1(0.8%). There were four cases of multiple genotypes; G1/G2, G1/G4, G1/G9, G8/G9 and genotype of G3, G8 were not found. Twenty three(19.2%) samples were nontypeable. The incidence of P was as follow; P[4] 77(64.2%), P[6] 22(18.3%), P4/P6 12(10%), P[4]/P[8] 1(0.8%) p[8] 1(0.8%). Seven(5.9%) samples were nontypeable. Conclusion : Various combinations of G and P genotypes were observed. Most rotavirus strains were P[4]G2 62(51.74%), followed by P[6]G2 7(5.8%), and P[6]G1 7(5.8%), P[4/P[6] G1 4(3%), P[4]/P[6]G2 4(3%), P[4]G1 3(2.5%), P[8]G2 1(0.8%), P[4]G4 1(0.8%) in Kyoungsangnamdo, Korea during 2000~2001.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.367-374
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• 1997

Bovine rotaviruses(A, 288, 55086 strains) isolated from fecal samples in Korea were propagated onto MA104 cells and were confirmed tentatively as G6, G8, and G10, respectively, by RFLP analysis. Full-length VP7 gene of these isolates was amplified by reverse transcriptase polymerase chain reaction(RT-PCR) using VP7 specific primers and cloned into TA vector. Nucleotide and deduced amino acid sequences of VP7 genes of the isolates were determined and compared with those of bovine rotavirus reference strains(NCDV; G6, UK; G6, Cody I-801; G8 and B223; G10). A, 288 and 55086 isolates showed high degree of nucleotide sequence homology with NCDV and UK(93% and 94%), Cody I-801(86%) and B223(97%), respectively, However, they showed 71~74% of nucleotide sequence homlogy with bovine rotavirus reference strains which belong to different serotypes. From the results of deduced amino acid sequence homology analysis, three isolates showed 94~96% of homology with the same serotype reference strains but 80~84% of homology with the different serotype reference strains. Three bovine rotavirus isolates, A, 288 and 55086 strains, were confirmed as G6, G8, and G10, respectively, by nucleotide and deduced amino acid sequence analysis.

• Microbiology and Biotechnology Letters
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• v.49 no.1
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• pp.120-129
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• 2021

Rotavirus A (RVA) is recognized as a major etiology responsible for the development of acute gastroenteritis in children worldwide. The purpose of the present study was to perform the molecular characterization of RVA. A total of 323 stool specimens collected from hospitalized children with acute gastroenteritis in Chiang Rai, Thailand, in 2016-2018 were identified for G- and P-genotypes through RT-PCR analysis. RVA was more prevalent in 2017-2018 (37.8%) than in 2016-2017 (23.2%). The seasonal peak of RVA occurred from March to April. G3P[8] was predominant in 2016-2017 (90.6%) and 2017-2018 (58.6%). Other genotypes including G1P[8], G8P[8], G9P[8], and mixed infections were also identified. G3P[8] strains clustered together in the same lineage with other novel human equine-like G3P[8] strains previously identified in multiple countries and presented a genotype 2 constellation (G3-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2). Several amino acid differences were observed in the antigenic epitopes of the VP7 and VP8* capsid proteins of the equine-like G3P[8] compared with those of the RVA vaccine strains. The homology modeling of the VP7 and VP8* capsid proteins of the equine-like G3P[8] strains evidently exhibited that these residue differences were present on the surface-exposed area of the capsid structure. The emergence of the equine-like G3P[8] strains in Thailand indicates the rapid spread of strains with human and animal gene segments. Continuous surveillance for RVA is essential to monitor genotypes and genetic diversity, which will provide useful information for selecting rotavirus strains to develop a safe and effective RVA vaccine that is efficacious against multiple genotypes and variants.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.353-356
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• 2004

Rotavirus and Norovirus are major causative agents of acute diarrhea and gastroenteritis. In our study, Each viral RNA was isolated from the feces of patients for viral diarrhea in Korea, respectively. And cDNA library were constructed using RT-PCR. Also, cDNAs encoding VP8 derived from Rotavirus and Capsid protein derived from norovirus were subesequently cloned and expressed in Echerichia coli as a fusion antigen. Molecular weight of fusion antigen was approximately 60kDa. Also, substantial overexpression was accomplished. We yielded egg yolk lgY which is potentially useful in controlling of Rotavirus and Norovirus which are one of the most prevalent pathogenic viruses.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.3 no.1
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• pp.41-46
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• 2000

Purpose: It is important to have the epidemiologic data of rotavirus serotypes for the application of polyvalent rotavirus vaccines. Epidemiological studies of rotavirus serotypes in Korea have been reported only in limited areas with small number of cases. Authors tried to investigate the distribution of rotavirus G serotypes in ChungJu area with RT-PCR. Method: Stool specimens were collected from 202 children with acute diarrheal symptoms, who admitted to or visited Kon-Kuk University Hospital in ChungJu from June 1998 to May 1999. Samples were screened for rotavirus with EIA method (TestPack Rotavirus, Abbott Laboratories) and rotavirus G Serotypes were determined by RT-PCR. Results: Rotavirus was positive in 46.6%. The incidence of G serotypes was as follows; G1 10%, G2 10%, G3 28%, G4 26%, and G9 20%. There were three cases of multiple serotypes; G1 with G9, G2 with G9, and G4 with G9. Serotype of G8 was not found. Conclusion: The proportion of G serotypes in ChungJu is much different from previous reports. Serotype of G9 was found which had not been reported in Korean children till now. Long term plans for the investigation of rotavirus serotypes must be needed in wide area.

• Pediatric Infection and Vaccine
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• v.22 no.2
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• pp.81-90
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• 2015

Purpose: Group A rotavirus (RV) is most common etiologic agent of acute gastroenteritis (AGE) in children worldwide. Recently, vaccination has been introduced in several countries to reduce the disease burden caused by RV infections, but continuous surveillance of RV strains is necessary to detect the emergence of potential variants induced by vaccine-immune pressure. This study aimed to investigate the changing pattern of RV genotypes in children with AGE, following the introduction of vaccination in Korea. Methods: Genotyping of RVs by RT-PCR on the basis of VP7 and VP4 gene segment sequence was carried out on 201 rotavirus-positive stool samples, from children hospitalized with AGE between August 2009 and June 2013. We have directly sequenced PCR products and analyzed the phylogenetic tree. Results: The most prevalent G genotype was G9 (33.3%), followed by G1 (22.4%), G3 (15.9%), G2 (6.0%), G4 (3.0%), G10 (1.5%), and mixed G-type (15.4%), with some nontypeable cases (2.5%). The detected P genotypes were P[4] (45.3%), P[8] (43.8%), mixed P-type (10.4 %), and P[2] (0.5%). The G9P[4] genotype was predominantly observed in hospitalized cases in Seoul in 2010/2011, however G1P[8] has been re-emerged as the predominant genotype in the following season (P =0.004). Conclusions: It seems that the periodic fluctuation in predominance of the G1, G3, and G9 strains occurred in Korea during 2009-2013, following the introduction of RV vaccination.

• The Journal of Korean Society of Virology
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• v.30 no.3
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• pp.189-202
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• 2000

This study was conducted to see what types of bovine rotaviruses were isolated at Jedong farm in Jeju province and Seohwa farm in Chungnum province. The results were as follows. 1. Rotavirus was positively detected in 18 out of 39 fecal samples from calves with diarrhea in Jeju province and in 13 out of 18 fecal samples from calves with diarrhea in Chungnam province. 2. The electropherotype pattern of dsRNA for 31 viruses was shown to be 4 : 2 : 3 : 2 type like traditional group A and the imigration pattern of dsRNA was the long type like NCDV (G6), JBR (G6), B223 (G10) and KK3 (G10). 3. The serotypes of the 18 viruses of Jedong and 9 viruses of Seowha were shown to be group A, subgroup I, G6, and P1 by ELISA and PCR analyses. The serotypes of S-2, S-6, S-9 and S-12 viruses of Seowha were shown to be group A, subgroup I, G10, but was not shown to be P type. 4. The partial nucleotide sequence of VP4 of S-8 was 97% homology with that of BRV 033. VP4 of J-10 showed 96% homology with that of BRV 033 in nucleotide sequence.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.296-301
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• 2014

Rotavirus is a major cause of acute gastroenteritis in young children in developed and developing countries. The use of probiotics for the treatment of gastrointestinal diseases is both safe and easily accessible. In this study, we evaluated the anti-rotaviral activities of probiotic mixtures in a Sprague-Dawley rat. 24 litters with their dams were randomly assigned to four groups; placebo, phosphate buffered saline (PBS), and two probiotic mixture (PRO-1 and PRO-2) groups. All rats were inoculated with rotavirus at dose of 8 log plaque forming units per rat at 5 days old. Animals in the PRO-1 and PRO-2 groups were orally administered probiotic mixtures 1 or 2, respectively, at a dose of 8 log colony forming units daily during 4 days. For control purposes, placebo and PBS groups were orally administered the same amount of placebo (containing maltose and polydextrose) or PBS once daily for 4 days, respectively. Antiviral analysis was performed by real-time quantitative PCR (RT-qPCR) and observing intestinal villi. As a result, weights of small intestines were greater in the PRO-1, PRO-2 groups than in control groups. Villi were short and villous epithelial necrosis was exhibited in control groups, but these morphological changes were not observed in PRO-1, PRO-2 treated rats. RT-qPCR analysis showed that VP7 gene level of rotavirus in fecal samples and small intestinal epithelial cells were lower in the PRO-1 and PRO-2 groups. These findings suggest that probiotic mixtures may be useful probiotics for the treatment of or as alternative therapies for rotaviral gastroenteritis.

• Korean Journal of Veterinary Research
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• v.36 no.2
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• pp.395-403
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• 1996

Monoclonal antibodies(MAbs) against field isolates of the bovine rotavirus A strain(G6), V strain(G10) and reference I-801 strain(G8) were produced and characterized. Six MAbs(4C2, 4D9, 5E1, 5E7, 5D5, 3E4) against A strain had neutralizing activity and reacted only with the G6 bovine rotaviruses determined by fluorescence focus neutralization (FFN) test. Otherwise, five neutralizing MAbs(1G2, 2G6, 5E2, 5E12, 5H7) against I-801 strain neutralized the G6 and G8 bovine rotaviruses. Five non-neutralizing MAbs(5F12, 7F12, 5E11, 2A11, 2B12) were VP6-specific and cross-reacted with all bovine and porcine rotaviruses examined by fluorescence antibody(FA) test. None of the MAbs reacted with bovie viral diarrhea virus(BVDV) and bovine coronavirus(BCV) determined by FA and FFN test.