• Journal of Microbiology and Biotechnology
• /
• v.16 no.7
• /
• pp.1017-1025
• /
• 2006

Hantaviruses possess three RNA segments of negative sense. Co-infection of closely related hantaviruses may result in generation of a progeny virus with genomic polyploidy, containing a partial or complete set of genome originated from more than one parental virus. To characterize the formation of viral genomic polyploidy, cultured Vero-E6 cells were co-infected with two closely related hantaviruses, Hantaan and Maaji, and the progeny viruses examined. The genotype of plaque-purified viruses was analyzed by a virus-specific RT-PCR. Seventy percent (67/96) of the progeny virus was categorized as Hantaan and 3.3% (2/96) was classified as Maaji, whereas 20% (21/96) was considered polyploidy as they contained both types of the S RNA segment. Most of the polyploidy progeny viruses were unstable and gave rise to either one of the parental viruses or a reassortant after several rounds of plaque purification. No recombination between the heterologous pair of S RNA was observed for those polyploid viruses during three consecutive plaque-to-plaque passages. These data suggest that the viral polyploidy formation constitutes a primary mechanism underlying the generation of a newly emerged hantavirus.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.2
• /
• pp.210-217
• /
• 2018

A one-step multiplex reverse transcription PCR (RT-PCR) method comprising six primer sets (for the detection of norovirus GI and GII, hepatitis A virus, rotavirus, and astrovirus) was developed to simultaneously detect four kinds of pathogenic viruses. The size of the PCR products for norovirus GI and GII, hepatitis A virus (VP3/VP1 and P2A regions), rotavirus, and astrovirus were 330, 164, 244, 198, 629, and 449 bp, respectively. The RT-PCR with the six primer sets showed specificity for the pathogenic viruses. The detection limit of the developed multiplex RT-PCR, as evaluated using serially diluted viral RNAs, was comparable to that of one-step single RT-PCR. Moreover, this multiplex RT-PCR was evaluated using food samples such as water, oysters, lettuce, and vegetable product. These food samples were artificially spiked with the four kinds of viruses in diverse combinations, and the spiked viruses in all food samples were detected successfully.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.11
• /
• pp.1885-1889
• /
• 2007

The tissue blot immunobinding assay (TBIA) is widely used for the detection and localization of plant viruses in various plant tissues. The basic experimental procedures of TBIA sampling and blotting were simplified using commercially available micropipette tips. This method was termed the ring-blot immunobinding assay (R-BIA), as the blot on the membrane forms a ring shape. The detection efficacy of R-BIA was tested for two chili pepper viruses, pepper mild mottle tobamovirus (PMMoV) and pepper mottle potyvirus (PepMoV), following the optimized serological procedures of TBIA (length of the incubation period and BSA concentration, and primary and secondary antibodies). Sensitivity of the R-BIA was about 1 ng/ml of purified PMMoV in pepper leaf sap from a healthy pepper plant. R-BIA also showed high specificity in the detection of PMMoV and PepMoV. Moreover, the modified sampling and blotting procedures were simpler and more reliable than other TBIA methods (such as whole-leaf blotting and crushed-leaf blotting), suggesting that the R-BIA may be used for medium- to large-scale detection of plant viruses in laboratories with minimal facilities.

• Clinical and Experimental Pediatrics
• /
• v.52 no.3
• /
• pp.269-276
• /
• 2009

Viruses are the most common cause of lower respiratory tract infections (LRTIs) in infants and young children and are a major public health problem in this age group. Viruses were identified in 54.9-70.4% of hospitalized infants and children with LRTIs in Korea. The viral pathogens identified included respiratory syncytial virus (RSV) A and RSV B, influenza (Inf) A, Inf B, parainfluenza (PIV)1, PIV2, human bocavirus (hBoV), human rhinovirus (hRV), adenovirus (ADV), human metapneumovirus (hMPV), human coronavirus (hCoV)-OC 43, hCoV-229E, hCoV-NL63, hCoV-HKU1, and human enterovirus (hEV). Coinfections with ${\geq}$2 viruses were observed in 11.5-22.8% of children. The occurrence of LRTIs was the highest in the first year of life. The specific viruses are frequently associated with specific clinical syndromes of LRTIs. LRTIs caused by RSV were predominant among younger infants. hRV accounted for a larger proportion of LRTIs in young infants than ADV and hBoV. hMPV was frequently detected in children >24 months old. The number of hMPV infections peaked between February and May, whereas hRV was detected throughout the year. Thus far, hCoV is a less common respiratory pathogen in cases of ALRI and URI in Korean children.

• The Plant Pathology Journal
• /
• v.29 no.3
• /
• pp.338-343
• /
• 2013

A detection system based on a multiplex reverse transcription (RT) polymerase chain reaction (PCR) was developed to simultaneously identify multiple viruses in the lily plant. The most common viruses infecting lily plants are the cucumber mosaic virus (CMV), lily mottle virus (LMoV), lily symptomless virus (LSV). Leaf samples were collected at lily-cultivation facilities located in the Kangwon province of Korea and used to evaluate the detection system. Simplex and multiplex RT-PCR were performed using virus-specific primers to detect single- or mixed viral infections in lily plants. Our results demonstrate the selective detection of 3 different viruses (CMV, LMoV and LSV) by using specific primers as well as the potential of simultaneously detecting 2 or 3 different viruses in lily plants with mixed infections. Three sets of primers for each target virus, and one set of internal control primers were used to evaluate the detection system for efficiency, reliability, and reproducibility.

• The Journal of Information Systems
• /
• v.15 no.1
• /
• pp.145-168
• /
• 2006

Current computer viruses are one of the most serious problems in information age due to their potential demage and impact on use of information systems. To make the problem worse, virus development technology has been advanced rapidly, and use of network systems has expanded widely. Therefore computer viruses are much more complex and use of anti-virus software(AV S/W) is not enough to prrevent virus incidents. It implies that computer viruses as well as other information security matters are not solely a technical problem but also a managerial one. This study emphasized on computer virus controls from managerial perspective of information security and investigated factors influencing the effectiveness of computer virus controls. Organization's comprehensive security policies provide guidelines on how organization or individual can protect themselves from computer viruses. Especially, user's education has positive impact on user's security related characteristics. Based on the analysis of research model using structural equation modeling technique, security policies were influencing security controls and improving user's computer viruses related awareness. Also security controls had positive impact on security effectiveness. However, no significant relationship was found between user's security related characteristics and security effectiveness.

• Journal of Veterinary Science
• /
• v.22 no.2
• /
• pp.21.1-21.6
• /
• 2021

In this study, we describe the isolation and characterization of previously unreported Y280-lineage H9N2 viruses from two live bird markets in Korea in June 2020. Genetic analysis revealed that they were distinct from previous H9N2 viruses circulating in Korea and had highest homology to A/chicken/Shandong/1844/2019(H9N2) viruses. Their genetic constellation showed they belonged to genotype S, which is the predominant genotype in China since 2010, where genotype S viruses have infected humans and acted as internal gene donors to H5 and H7 zoonotic influenza viruses. Active surveillance and control measures need to be enhanced to protect the poultry industry and public health.

• The Plant Pathology Journal
• /
• v.37 no.3
• /
• pp.258-267
• /
• 2021

Asian pear (Pyrus pyrifolia) is a widely cultivated and commercially important fruit crop, which is occasionally subject to severe economic losses due to latent viral infections. Thus, the aim of the present study was to examine and provide a comprehensive overview of virus populations infecting a major pear cultivar ('Singo') in Korea. From June 2017 to October 2019, leaf samples (n = 110) of pear trees from 35 orchards in five major pear-producing regions were collected and subjected to RNA sequencing. Most virus-associated contigs matched the sequences of known viruses, including apple stem grooving virus (ASGV) and apple stem pitting virus (ASPV). However, some contigs matched the sequences of apple green crinkle-associated virus and cucumber mosaic virus. In addition, three complete or nearly complete genomes were constructed based on transcriptome data and subjected to phylogenetic analyses. Based on the number of virus-associated reads, ASGV and ASPV were identified as the dominant viruses of 'Singo.' The present study describes the virome of a major pear cultivar in Korea, and looks into the diversity of viral communities in this cultivar. This study can provide valuable information on the complexity of genetic variability of viruses infecting pear trees.

• Microbiology and Biotechnology Letters
• /
• v.51 no.2
• /
• pp.135-146
• /
• 2023

Viral oncology is focused on understanding the relationship between cancer and viruses, which are known to play a role in the development of certain types of cancer. Approximately 15-20% of human cancers are believed to be caused by oncogenic viruses, and as a result, there is significant interest in understanding how these viruses contribute to cancer development. There are several viruses that have been linked to cancer, including human papillomavirus, hepatitis B and C virus, Epstein-Barr virus, human T-cell lymphotropic virus type 1, Kaposi's sarcoma-associated herpesvirus, and Merkel cell polyomavirus. Each of these viruses is associated with different types of cancer, and the mechanisms by which they contribute to cancer development are diverse. This article discusses these mechanisms as well as current and future strategies for preventing and treating virus-associated cancers with the goal of presenting a thorough review of the current state of knowledge in viral oncology and to highlight the importance of continued research in this field.

• Korean Journal of Veterinary Service
• /
• v.20 no.2
• /
• pp.195-203
• /
• 1997

Fecal samples were collected from 47 calves with diarrhea and 12 clinically normal co-h-abitants, and tested for virus using MDBK cell cultures. Three cytopathic viruses were isolated from 8 fecal samples obtained from diarrheic calves. The isolated viruses were neutralized by bovine coronavirus hyperimmune serum In plaque reduction assay and were detected in the cytoplasm of MDBK cell by bovine coronavirus hyperimmune serum using immunofluorescence staining. The viruses agglutinated mouse erythrocytes only among the various animal erythrocytes tested and new isolates were identified as bovine coronavirus.