• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.300-307
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• 2006

In the present study, methods of the reverse transcription-polymerase chain reaction(RT-PCR) were evaluated for the rapid detection and differentiation of transmissible gastroenteritis virus(TGEV), porcine epidemic diarrhea virus(PEDV) and rotavirus in piglets suffering from diarrhea. For the purposes, the PCR conditions were first confirmed for the amplification of VP7 gene of rotavirus and N gene of TGEV and PEDV using each specific primers and their annealing temperature. Multiplex RT-PCR methods were further determined to distinguish these viral infections and the results are as follows. For the specific amplification of these viral genes, the reliable PCR condition was determined as 30 cycles of reaction consisting each 1 min of denature at $94^{\circ}C$, annealing at $42^{\circ}C$ and polymerization at $72^{\circ}C$ with 1.0 mM $MgCl_2$. It was able to differentiate these viral infections in the intestines and feces of piglets suffering from diarrhea by duplex PCR for TGEV and PEDV and single PCR for rotavirus with a primer-annealing temperature of $42^{\circ}C$. When the multiplex RT-PCR were undertaken for the field samples, 17 cases of PEDV and 5 cases of rotavirus infections were differential diagnosed in a total of 92 samples of intestines and feces of the piglets with diarrhea.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.267-274
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• 2015

Biopharmaceuticals and the cell substrates used for their manufacture are currently tested for porcine adventitious viruses due to the widespread use of porcine trypsin in cell culture. Porcine transmissible gastroenteritis virus (PTGV) is one of the major adventitious porcine viruses causing contaminated during the manufacture of biopharmaceuticals. Therefore, rapid and sensitive detection of PTGV is essential in ensuring the safety of biopharmaceuticals. A TaqMan probe real-time RT-PCR method was developed for the quantitative detection of PTGV contamination in cell substrates, raw materials, manufacturing processes, and final products, as well as PTGV clearance validation. Specific primers for the amplification of PTGV RNA were selected, and PTGV RNA was quantified by use of a specific TaqMan probe. Specificity, limit of detection (LOD), and robustness of the method was validated according to international guidelines on the validation of nucleic acid amplification tests. The sensitivity of the assay was calculated to be 1.10 × 10⁰ TCID₅₀/ml. The real-time RT-PCR method was validated to be reproducible, very specific to PTGV, and robust. The established real-time RT-PCR assay was successfully applied to the validation of Chinese Hamster Ovary (CHO)-K1 cells artificially infected with PTGV.

• Korean Journal of Veterinary Service
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• v.37 no.4
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• pp.263-271
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• 2014

In this study, we developed a cost and time saving one-step multiplex RT-PCR for the simultaneous detection and differentiation of swine influenza viruses (SIV) and 2009 pandemic influenza H1N1 virus (pH1N1). The one-step multiplex RT-PCR using four sets of primer was confirmed to be capable of detection of all SIV subtypes and differential diagnosis of major SIV subtype H1, H3 and pH1N1 on individual or mixed viral culture samples. The sensitivity of the multiplex RT-PCR was determined to be at least $2^{-6}$ $HA/25{\mu}L$ of the presented SIVs, providing sufficient efficacy for a routine SIV monitoring in diagnostic laboratories. In addition, compared with the conventional RT-PCR methods that cannot avoid the carryover DNA contamination, the developed RT-PCR applied with the uracil DNA glycosylase (UNG) system was proven to prevent a false positive reaction by carryover contamination of the pre-amplified DNA. In conclusion, the one-step RT-PCR with UNG system could be applicable to detect and differentiate of SIV from the viral cultures without worry of carryover DNA contamination in clinical laboratories.

• Korean Journal of Microbiology
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• v.49 no.3
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• pp.270-274
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• 2013

The bumblebee, Bombus terrestris, has played an important role as one of the alternative pollinators since the outbreak of honeybee collapse disorder. Recently, pathogens and parasites such as viruses, bacteria and mites, which affect the life span and fecundity of their host, have been discovered in B. terristris. In order to detect the microsporidian pathogen, Nosema spp. in the field populations of B. terristris, we collected adults and isolated their genomic DNA for diagnostic PCR. The PCR primers specific for Nosema spp. were newly designed and applied to gene amplification for cloning. Only small subunit ribosomal RNA (SSU rRNA) gene of N. ceranae was successfully amplified among examined genes and sequenced, which indicates that N. ceranae mainly infects the examined field population of B. terristris. To detect of SSU rRNA gene, two regions of SSU rRNA gene were selected by primary PCR analysis and further analyzed in quantitative real-time PCR (qRT-PCR). The qRT-PCR analysis demonstrated that SSU rRNA of N. ceranae was detected at concentration as low as $0.85ng/{\mu}l$ genomic DNA. This result suggests that the detection via qRT-PCR can be applied for the rapid and sensitive diagnosis of N. ceranae infection in the field population as well as risk assessment of B. terristris.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.1018-1023
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• 2005

Simplified procedure was developed for concentrating and detecting poliovirus and norovirus in oysters. Viruses were seeded into oyster tissue homogenates and concentrated through polyethylene glycol (PEG) precipitation, chloroform or Freon extraction, with additional PEG precipitation. Amount of viruses was evaluated using poliovirus plaque assay. Virus recovery during concentration procedure was approximately 16.4-26.0%. For defection, viral RNAs in oysters were examined using one-step RT-PCR after extraction with Trizol. Dilution or capturing of viral RNA using silica gel membrane allowed viruses to be detected by RT-PCR, whereas viruses could not be removed using $QIAshredder^{TM}$ Homogenizer, which is effective in removing RT-PCR inhibitors in lettuce and hamburgers. Freon extraction, generally used to concentrate viruses found in food, could be substituted with chloroform extraction using this procedure; no difference could be observed between detection limits of whole oyster extracts and digestive organ extracts indicating that RT-PCR inhibitors were distributed evenly throughout whole tissues. Nested PCR greatly improved efficiency of this procedure. Overall, this procedure could remove sufficient amount of inhibitors to allow detection of norovirus in oysters.

• Pediatric Infection and Vaccine
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• v.25 no.2
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• pp.91-100
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• 2018

Purpose: This study investigated the factors affecting the use of empirical antibiotics in febrile infants from 1 month to less than 3 months. Methods: We retrospectively reviewed the medical records of hospitalized previously healthy infants with fever in Pusan National University Children's Hospital from January 2010 to December 2016. Clinical features, laboratory findings and antibiotic therapy were analyzed. Respiratory viruses were identified by multiplex reverse transcriptase polymerase chain reaction (RT-PCR) and were reported after 1-3 days. Enterovirus were identified by real time polymerase chain reaction (PCR) and were reported in several hours. Results: The 129 of 366 subjects used empirical antibiotics and 237 patients didn't used empirical antibiotics. Empirical antibiotics were used more frequently when the fever was longer before admission, respiratory symptoms and ill being appearances were present and C-reactive protein was elevated. The rate of readmission was low in the group not used empirical antibiotics. Most of the patients detected by enterovirus PCR in cerebrospinal fluid didn't used empirical antibiotics. The results of respiratory virus multiplex RT-PCR showed no difference in the use of empirical antibiotics. Conclusions: In our study, empirical antibiotic prescriptions were affected not respiratory virus multiplex RT-PCR but enterovirus PCR. If multiplex RT-PCR were reported more rapid turn around time, it will affect antibiotic use.

• Research in Plant Disease
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• v.7 no.2
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• pp.80-85
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• 2001

This study was carried out to examine tne incidences of virus diseases in lily plants cultivated in highland areas, and to develop an effective detection method. Viral symptoms on lilies in the highland areas were differentiated into mosaic, crinkle, mottle, stripe and line pattern. The distribution of symptoms on infected plants was 43.8% of mosaic, 29.2% of crinkle, and 10.9% of mottle symptoms. Six viruses such as Lily symptomless vires(LSV), Cucumber mosaic virus (CMV), Lily mottle virus (LMoV), Lily virus X (LVX, Potexvirus), Tabacco mosaic virus (TMV,Tobamovirus), and Tabacco rattle virus (TRV,Tobravirus) were detected from the infected lilies. Infection rate of Lilium oriental (cvs. Casablanca and Marcopolo) was 2~4 times higher than that of L. asiatic (cvs. Solemio and Prato). Virus detection on lilies by one-step RT-PCR (by using reverse transcription and polymerase chain reaction simultaneously) was more rapid rapid and reliable than by the conventional RT-PCR method.

• Journal of Microbiology and Biotechnology
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• v.31 no.12
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• pp.1709-1715
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• 2021

Outbreaks of food poisoning due to the consumption of norovirus-contaminated shellfish continue to occur. Male-specific (F+) coliphage has been suggested as an indicator of viral species due to the association with animal and human wastes. Here, we compared two methods, the double agar overlay and the quantitative real-time PCR (RT-PCR)-based method, for evaluating the applicability of F+ coliphage-based detection technique in microbial contamination tracking of shellfish samples. The RT-PCR-based method showed 1.6-39 times higher coliphage PFU values from spiked shellfish samples, in relation to the double agar overlay method. These differences indicated that the RT-PCR-based technique can detect both intact viruses and non-particle-protected viral DNA/RNA, suggesting that the RT-PCR based method could be a more efficient tool for tracking microbial contamination in shellfish. However, the virome information on F+ coliphage-contaminated oyster samples revealed that the high specificity of the RT-PCR- based method has a limitation in microbial contamination tracking due to the genomic diversity of F+ coliphages. Further research on the development of appropriate primer sets for microbial contamination tracking is therefore necessary. This study provides preliminary insight that should be examined in the search for suitable microbial contamination tracking methods to control the sanitation of shellfish and related seawater.

• The Journal of Korean Society of Virology
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• v.28 no.2
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• pp.147-155
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• 1998

Hantavirus is a genus of the Bunyaviridae family consisting following serotype groups: Hantaan, Seoul, Puumala, Prospect Hill, Thailand, Belgrade, Thotta palayam, Sin Nombre. Most of Hantavirus group have been associated with many clinically similar disease known collectively as hemorrhagic fever with renal syndrome (HFRS). Hantaan virus is the prototype of the genus hantavirus, originally isolated from Apodemus agrarius. Bat was found as a natural host for Hantaan virus in Lee's lab for the first time. Then, Hantaan-like virus was isolated Hantaan-like virus from bat. To identify hantaviruses that are present in Korea among bats, bats were collected from Jeong-Sun, Won-Joo, Chung-Ju and Hwa-Cheon area, RNA was isolated from lung and serum. RT-PCR was performed with a universal primer from M segment. Nested RT-PCR was carried out to differentiate Hantaan, Seoul and Puumala virus using serotype specific primers. As we expected, Hantaan viruses were detected in bats and Seoul virus was not detected. Interestingly, Puumala viruses were also detected in bats from Won-Ju, but not in other areas. Puumala virus is originally isolated from Clethrinomys glareolus, and cause light HFRS. Recently, Paradoxomis webbiana, a wild bird turn out to be a reservoir for Puumala virus in Korea. These data indicate that bat is a new natural reservoir of Puumala virus.

• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.104-110
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• 1999

Field infectious bursal disease viruses (IBDVs) were isolated from IBDV-suspected commercial chickens. The variable region in VP2 gene of six Korean IBDV isolates (K-IBDVs) and IBD vaccines was examined using the reverse transcriptase / polymerase chain reaction-restriction fragment length polymorphism (RT/PCR-RFLP) assay. With all K-IBDVs and vaccine IBDVs, a 474-bp fragment of the VP2 gene was amplified and tested with various restriction enzymes. Restriction enzymes BstNI and StyI differentiated K-IBDV isolates and IBD vaccines into four groups. Restriction enzyme profiles of K-IBDV isolates were different from them of IBD vaccines. K-IBDV isolates except for 310 isolate had specific SspI and TaqI recognition sites, which were recognized in highly virulent IBDVs, but IBD vaccines had no those sites. This study showed that RT/PCR-RFLP assay was thought to be valuable tool for differentiation of IBDVs and identification of highly virulent IBDV.