• Journal of Veterinary Science
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• v.22 no.5
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• pp.69.1-69.12
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• 2021

Background: Bovine group A rotavirus (BoRVA) is a major cause of severe gastroenteritis in newborn dairy calves. Only one study has investigated the G and P genotypes among dairy calves in a few regions of China, which were G6 and P[5]. Therefore, data on the prevalence and molecular characteristics of BoRVA in dairy calves in China remains limited. Objectives: The purpose of this study was to investigate the prevalence and molecular characteristics of BoRVA in dairy calves in China. Methods: 269 dairy calves diarrheic samples from 23 farms in six provinces in China were collected to detect BoRVA using reverse transcription polymerase chain reaction. Results: 71% of samples were determined to be BoRVA-positive. Two G genotypes (G6, G10) and two P genotypes (P[1], P[5]) were identified, and G6P[1] BoRVA was the predominant strain. Moreover, the VP7 and VP4 gene sequences of these dairy calf BoRVA strains revealed abundant genetic diversity. Interestingly, eight out of 17 complete G6 VP7 sequences were clustered into G6 lineage VI and analysis showed the strains were closely related to Chinese yak BoRVA strains. Conclusions: The results of this study show that BoRVA circulates widely among dairy calves in China, and the dominant genotype in circulation is G6P[1], first report on molecular characteristics of complete P[5] VP4 genes in chinese dairy calves. These results will help us to further understand the prevalence and genetic evolution of BoRVA among dairy calves in China and, thus, prevent the disease more effectively.

• Clinical and Experimental Pediatrics
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• v.58 no.3
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• pp.102-107
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• 2015

Purpose: Human parechovirus (HPeV) and enterovirus (EV) are causative agents of a sepsis-like illness in neonates and of infections of the central nervous system in young children. The objectives of this study were to assess the prevalence of HPeV3 and EV infection in young children with a sepsis-like illness or with meningitis in Jinju, Korea. Methods: Cerebrospinal fluid (CSF) samples were collected from 267 patients (age range, 1 day to 5 years) and assessed for HPeV and EV by performing reverse transcription polymerase chain reaction assay. Amplification products of the VP3/VP1 region of HPeV and of the VP1 region of EV were sequenced to identify the virus type. Results: HPeV and EV were detected in 3.4% and 7.5% of the total CSF samples assessed, respectively. The age distribution of EV-positive patients (median age, 1.4 months) had a significantly broader range than that of HPeV-positive patients (median age, 7.8 months). The peak seasons for HPeV and EV infection were spring and summer, respectively. The clinical symptoms for HPeV and EV infection were similar, and fever was the most common symptom. Pleocytosis was detected in 22.2% of HPeV-positive patients and 35.5% of EV-positive patients. The VP3/VP1 gene sequence of the nine Korean strains clustered most closely with the Japanese strain (AB759202). Conclusion: The data indicate that HPeV infection is predominant in young infants (<6 months) and that meningitis without pleocytosis was caused by both HPeV and EV infection in children.

• 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.

• Journal of Life Science
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• v.20 no.6
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• pp.907-913
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• 2010

Human enteroviruses (HEV) are considered one of the major infectious causes of central nervous system infections such as aseptic encephalomeningitis in pediatrics. This study was focused on providing information related to genetic characteristics and diversities of HEV which prevailed between 2007 and 2009 in Busan, Korea. A total of 2,743 specimens were collected from children and screened for isolation of HEV by cell culture and RT-PCR. Among the specimins, 240 isolates were grouped into 21 different HEV serotypes using VP1 RT-PCR. The major etiological agents were CV-A6 and CV-B2 in 2007, E-6 and E-30 in 2008 and CV-B1 in 2009. The occurrence of HEV infections was the most frequent in the summer (May to August, 188 cases, 78.3%). Most of the isolates were identified from specimens from children under 10 years old, with the highest occurrence in the 2 to 4 year old range (15.2%). However, there were no significant differences between male and female children for the isolates. For analyzing genetic characterization, VP1 gene was amplified by RT-PCR and sequenced. The phylogenetic tree was established by Clustal W method using DNASTAR software. Using the sequence analysis of the VP1 region, it was classified into 2 groups; HEV-A and HEV-B. The HEV-A group contained 6 serotypes and sequences of 31 isolates were compared within each serotype. The HEV-B group contained 10 serotypes and the sequences of 41 isolates were compared within each serotype. Homology analysis of the VP1 region showed that the identity scores of HEV-A and B isolates were different. In conclusion, genetic divergences were observed among the isolates from children between 2007 and 2009 in Busan.

• Environmental Analysis Health and Toxicology
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• v.21 no.3 s.54
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• pp.291-299
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• 2006

The experiments investigated whether early exposure to testosterone propionate (TP) during prepuberty alters testis development in Sprague-Dawley male rats. We performed Hershberger assay using the stimulated weanling male rats by OECD protocols, cDNA microarray, and Western blot. TP was subcutaneously injected to uncastrated Sprague-Dawley male rat of 22 days old for 10 consecutive days at doses of 0.4, 0.8, 1.0, 1.2, 1.6 mg/kg per day. At necropsy, the following tissues were removed and weighed: combined testes, epididymides (Epi), Cowper's glands (COW), levator am, and bulbocavernosus muscles (LABC), seminal vesicles, together with coagulating gland (SV) and ventral prostate (VP). We found that TP increased the weights of Epi, VP, SV, COW, and LABC, while testis was decreased in a dose-dependent manner. In cDNA microarray analysis of testis, there were significant reductions in the expression of cytochrome P450 11A (CYP11A), the rate-limiting enzyme of steroidogenesis. Taken together these results, TP exposure before puberty in male rats may produce the delay in testis development by inhibiting the CYP11A gene expression.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.1055-1064
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• 2009

Enteroviruses were identified and characterized from patients with aseptic meningitis and other enterovirus-related diseases in Chungnam, Korea from 2005 to 2006. Enteroviruses were isolated from 79 of 519 cases (15.2%) in 2005, and 37 of 386 cases (9.6%) in 2006. Based on partial VP1 sequencing, a total of 116 enterovirus isolates were resolved into 13 types. Prevalent among the Chungnam isolates were echovirus 18 and coxsackievirus B5 in 2005, and echoviruses 5 and 25 in 2006. This is the first time echoviruses 5 and 18 have been identified in Korea since enterovirus surveillance began there in 1993. The temporal distribution of enterovirus epidemics in Chungnam showed a remarkable seasonal pattern, with cases occurring during most of the three months of the summer from June to August. The highest rate of enterovirus-positive cases occurred in patients less than 1 year of age. The ratio of male to female enterovirus-positive patients was approximately 1.8:1. Comparison of the VP1 amino acid sequences of the 15 coxsackievirus B5 isolates with reference strains revealed that all Chungnam isolates are substituted at positions 23 (V231), 19 (S19G), 75 (Y75F), and 95 (N95S). Upon comparing the nine ECV5 isolates with foreign strains, it was found that only the Chungnam isolates, with the exception of Kor06-ECV5-239cn, have P at position 153 and F at position 146. The three ECV9 isolates from 2006 show alterations at amino acids 36, 148, and 154 outside of the BC-loop and at position 84 in the BC-loop, whereas the seven isolates from 2005 and the other ECV9 strains in the database only show the alteration at position 84 (D, I, N, S). The five ECV25 isolates have an S residue at position 134, whereas most of the foreign strains have an N residue.

• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.588-591
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• 2018

Baculovirus was originally isolated from the alfalfa looper and contains a 134-kbp genome with 154 open reading frames (ORF). The major capsid protein VP39 together with some minor proteins forms the nucleocapsid ($21nm{\times}260nm$) that encloses the DNA with p6.9 protein. They are double-stranded, circular, supercoiled DNA molecules in a rod-shaped capsid. Wild-type baculoviruses exhibit both lytic and occluded life cycles that develop independently throughout the three phases of virus replication. Recombinant baculoviruses can transfer their vectors and express their recombinant proteins in a wide range of mammalian cell types. Especially, inclusion of a dominant selectable marker in these baculoviral vectors can express diverse recombinant genes in many cells. Baculoviral vectors were reconstructed with cytomegalovirus (CMV) promoter,uroplakin II promoter, polyhedron promoter, vesicular stomatitis virus G (VSVG), enhanced green fluorescent protein (EGFP), protein transduction domain (PTD) gene and so on. These reconstructed vectors were infected into various cell and cell lines. We performed transfection and expression of these recombinant vectors comparison with other control vectors. From this study, we knew that transfection and expression of these recombinant vectors have higher efficacy than any control vector. This work was supported by a grant from Mid-Career Researcher Program(NRF-2016R1A2B4016552) through the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT & Future Planning(MSIP).

• Journal of Life Science
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• v.27 no.3
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• pp.275-282
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• 2017

Adenovirus (ADV) and human bocavirus (hBoV) cause acute respiratory tract infections, and are often associated with increased rates of hospitalization and death, particularly in infants and young children. The aim of this study was to analyze the clinical features and molecular phylogeny of ADV and hBoV isolated in Busan, from January 2011 to November 2013. In total, 3,230 specimens (throat swabs) were collected from patients with influenza-like illnesses and acute respiratory tract infections. Multiplex real-time RT-PCR was performed to detect eight respiratory viru [rhinovirus, adenovirus, respiratory syncytial virus, human coronavirus, human metapneumovirus, human bocavirus, parainfluenza virus and influenza virus] and detected 1,485(46.0%) cases. Among 1,485 positive specimens, 257(8.0%) cases were ADV and 68(2.1%) cases of hBoV. A significant clinical feature of ADV is fever and headache whereas hBoV is wheezing. Serotypic distributions of isolated ADV and hBoV were analyzed by sequencing of hexon and VP1/VP2 gene, respectively. ADV was identified seven different serotypes(1~6, 8), revealing a high similarity among the isolates (>97%). The predominant types of ADV were type 1 in 2011, type 3 and 4 in 2012, type 3 in 2013, respectively. ADV type 3 was major causative type during outbreaks in 2013. All of the hBoV was identified as hBoV type 1.

• Pediatric Infection and Vaccine
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• v.16 no.1
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• pp.73-79
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• 2009

Purpose : We undertook this study to improve our understanding of the epidemiologic and clinical features of nonpolioenterovirus (NPEV) infections, especially enterovirus 71 (EV71) infections, in Korean children. Methods : Between April and June 2000, NPEVs were detected by RT-PCR and cultures of specimens obtained from patients with aseptic meningitis, acute respiratory disease, and acute gastroenteritis which were associated with enteroviral exanthem and vesicular pharyngeal enanthem, such as herpangina, and hand, foot, and mouth disease (HFMD). EV71 was identified by sequencing the VP1 gene. The clinical and epidemiologic data were analyzed retrospectively after all 87 NPEV-positive patients were divided into 4 groups, according to the clinical manifestations. Sixteen patients who mainly had symptoms of acute gastroenteritis were in group A, 21 patients with symptoms and signs of lower respiratory tract infections were in group B, 42 patients with a HFMD rash only were in group C with or without fever, and 8 patients with aseptic meningitis or paralysis were in group D. For the 11 EV71-positive patients, 1 was in group A, 2 were group B, 7 were in group C, and 1 was in group D. Results : There were 87 NPEV infections, including 11 EV71 infections. The mean age of the patients was 2 years and 11 months, ranging from 1 day to 15 years. There were no fatal cases among a total of 87 NPEV infections and no significant differences in clinical severity between the EV71 and other NPEV infections. Conclusion : NPEV infections in children were common during the 3 months in the spring of 2000. Unlike in southeast Asia, where fatal EV71 infection outbreaks have occurred since 1997, the clinical features of EV71 infection in Korean children are mild.